ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

Ihre E-Mail wurde erfolgreich gesendet. Bitte prüfen Sie Ihren Maileingang.

Leider ist ein Fehler beim E-Mail-Versand aufgetreten. Bitte versuchen Sie es erneut.

Vorgang fortführen?

Exportieren
Filter
  • Chemistry  (58.393)
  • LUNAR AND PLANETARY EXPLORATION  (3.867)
  • Chemical Engineering  (3.296)
  • AERODYNAMICS  (2.824)
  • 2020-2024  (47)
  • 1990-1994  (57.532)
  • 1900-1904
Sammlung
Schlagwörter
Erscheinungszeitraum
Jahr
  • 1
    facet.materialart.
    Unbekannt
    EDP SCIENCES
    Publikationsdatum: 2024-04-05
    Beschreibung: Chemistry
    Schlagwort(e): Chemistry ; thema EDItEUR::P Mathematics and Science::PN Chemistry ; thema EDItEUR::P Mathematics and Science::PN Chemistry::PNN Organic chemistry::PNNP Polymer chemistry
    Sprache: Französisch
    Format: image/jpeg
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 2
    facet.materialart.
    Unbekannt
    EDP SCIENCES
    Publikationsdatum: 2024-04-05
    Beschreibung: Chemistry
    Schlagwort(e): Chemistry ; thema EDItEUR::P Mathematics and Science::PN Chemistry ; thema EDItEUR::P Mathematics and Science::PN Chemistry::PNN Organic chemistry::PNNP Polymer chemistry ; thema EDItEUR::P Mathematics and Science::PN Chemistry ; thema EDItEUR::P Mathematics and Science::PN Chemistry::PNN Organic chemistry::PNNP Polymer chemistry
    Sprache: Französisch
    Format: image/jpeg
    Format: image/jpeg
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 3
    facet.materialart.
    Unbekannt
    EDP SCIENCES
    Publikationsdatum: 2024-04-07
    Beschreibung: Chemistry
    Schlagwort(e): Chemistry ; thema EDItEUR::P Mathematics and Science::PN Chemistry ; thema EDItEUR::P Mathematics and Science::PN Chemistry::PNN Organic chemistry::PNNP Polymer chemistry
    Sprache: Französisch
    Format: image/jpeg
    Format: image/jpeg
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 4
    facet.materialart.
    Unbekannt
    EDP SCIENCES
    Publikationsdatum: 2024-04-05
    Beschreibung: Chemistry
    Schlagwort(e): Chemistry ; thema EDItEUR::P Mathematics and Science::PN Chemistry ; thema EDItEUR::P Mathematics and Science::PN Chemistry::PNN Organic chemistry::PNNP Polymer chemistry ; thema EDItEUR::P Mathematics and Science::PN Chemistry ; thema EDItEUR::P Mathematics and Science::PN Chemistry::PNN Organic chemistry::PNNP Polymer chemistry
    Sprache: Französisch
    Format: image/jpeg
    Format: image/jpeg
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 5
    Publikationsdatum: 2024-04-05
    Beschreibung: Chemistry
    Schlagwort(e): Chemistry ; thema EDItEUR::P Mathematics and Science::PN Chemistry ; thema EDItEUR::P Mathematics and Science::PN Chemistry::PNN Organic chemistry::PNNP Polymer chemistry ; thema EDItEUR::P Mathematics and Science::PN Chemistry ; thema EDItEUR::P Mathematics and Science::PN Chemistry::PNN Organic chemistry::PNNP Polymer chemistry
    Sprache: Französisch
    Format: image/jpeg
    Format: image/jpeg
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 6
    facet.materialart.
    Unbekannt
    EDP SCIENCES
    Publikationsdatum: 2024-04-08
    Beschreibung: Chemistry
    Schlagwort(e): Chemistry ; thema EDItEUR::P Mathematics and Science::PN Chemistry::PNN Organic chemistry::PNNP Polymer chemistry
    Sprache: Französisch
    Format: image/jpeg
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 7
    facet.materialart.
    Unbekannt
    EDP SCIENCES
    Publikationsdatum: 2024-04-05
    Beschreibung: Chemistry;Materials science
    Schlagwort(e): Chemistry ; Materials science ; thema EDItEUR::P Mathematics and Science::PN Chemistry ; thema EDItEUR::P Mathematics and Science::PN Chemistry::PNN Organic chemistry::PNNP Polymer chemistry
    Sprache: Französisch
    Format: image/jpeg
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 8
    facet.materialart.
    Unbekannt
    EDP SCIENCES
    Publikationsdatum: 2024-04-05
    Beschreibung: Chemistry
    Schlagwort(e): Chemistry ; thema EDItEUR::P Mathematics and Science::PN Chemistry ; thema EDItEUR::P Mathematics and Science::PN Chemistry::PNN Organic chemistry::PNNP Polymer chemistry
    Sprache: Französisch
    Format: image/jpeg
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 9
    facet.materialart.
    Unbekannt
    IntechOpen | IntechOpen
    Publikationsdatum: 2024-04-05
    Beschreibung: Mineralogy includes thirteen chapters that discuss the methodology of specific mineralogical methods, the composition of minerals from different igneous rocks, and the composition of minerals from different sedimentary rocks.It contains detailed mineralogical studies from Africa, Asia, and Europe. Chapters present different scientific mineralogical methods and detailed descriptions of minerals from different magmatic and sedimentary rocks.
    Schlagwort(e): Chemistry ; thema EDItEUR::P Mathematics and Science::PN Chemistry::PNV Chemistry of minerals, crystals and gems
    Sprache: Englisch
    Format: image/jpeg
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 10
    facet.materialart.
    Unbekannt
    IntechOpen | IntechOpen
    Publikationsdatum: 2024-04-05
    Beschreibung: Benzimidazole is a comprehensive survey of the known and new methods of benzimidazole synthesis, the spectral and theoretical aspects of existing benzimidazole derivatives, and the anticancer properties of a new class of benzimidazole derivatives. This book examines aspects and newer mechanisms of benzimidazoles containing heterocyclic moiety. Chapters report on anticancer properties of benzimidazole derivatives, novel methods of synthesis of benzimidazoles, versatile nature of the benzimidazoles, spectral and theoretical studies of benzimidazole derivatives, and medicinal importance and pharmacological aspects of benzimidazole derivatives.
    Schlagwort(e): Chemistry ; thema EDItEUR::P Mathematics and Science::PN Chemistry::PNN Organic chemistry
    Sprache: Englisch
    Format: image/jpeg
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 11
    facet.materialart.
    Unbekannt
    IntechOpen | IntechOpen
    Publikationsdatum: 2024-04-05
    Beschreibung: Green Chemistry - New Perspectives is at the frontiers of this continuously evolving interdisciplinary science, and publishes research that attempts to reduce the environmental impact of the chemical enterprise by developing a technology base that is inherently non-toxic to living things and the environment. The book covers all aspects of green chemistry, including chemical synthesis, nano synthesis, eco-friendly processes, biomass, extraction techniques, environmental remediation, and energy, making it a unique reference resource. This will continue to encourage scientists around the world to develop novel synthetic methods or improve the existing ones to circumvent some of the problems and favours all aspects of green chemistry. This book is intended for academia, professionals, scientists, as well as graduate and undergraduate students without any geographical limitations.
    Schlagwort(e): Chemistry ; thema EDItEUR::P Mathematics and Science::PN Chemistry::PNN Organic chemistry
    Sprache: Englisch
    Format: image/jpeg
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 12
    facet.materialart.
    Unbekannt
    IntechOpen | IntechOpen
    Publikationsdatum: 2024-04-05
    Beschreibung: This book consists of several selected chapters on important subjects in modern high-performance liquid chromatography (HPLC) and ultra-performance liquid chromatography (UPLC). The content addresses aspects related to both improvements in the mainstream HPLC/UPLC technology and utilization, as well as developments of exploratory new materials and equipment. The book presents useful details about the presented subjects as well as describes new applications and/or relevant case studies for each subject. It is addressed to a large audience of analytical chemists involved in separation science. Each chapter is authored by scientists with considerable field and academic experience.
    Schlagwort(e): Chemistry ; thema EDItEUR::P Mathematics and Science::PN Chemistry::PNF Analytical chemistry
    Sprache: Englisch
    Format: image/jpeg
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 13
    facet.materialart.
    Unbekannt
    IntechOpen | IntechOpen
    Publikationsdatum: 2024-04-05
    Beschreibung: Recent Advances in Chemical Kinetics provides a comprehensive overview of several types of chemical reactions. It includes six chapters that discuss solvent catalysis, customized flow reactors, p-conjugation in kinetics, kinetics of autoxidation, molecular chameleon for cations and anions, and internal clocks of atoms.
    Schlagwort(e): Chemistry ; thema EDItEUR::P Mathematics and Science::PN Chemistry::PNR Physical chemistry
    Sprache: Englisch
    Format: image/jpeg
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 14
    facet.materialart.
    Unbekannt
    IntechOpen | IntechOpen
    Publikationsdatum: 2024-04-05
    Beschreibung: Redox reactions are involved in biochemistry, energy, corrosion, and much more. In both biology and electrochemistry, the redox reaction is complex and varied. For example, redox shuttles in supercapacitors show aspects of molecular electrochemistry applied to electrode porosity. In pseudocapacitors, the formalism associated with their electrochemical response requires investigation and formalism. Similarly, the simple definition of redox potential opens fundamental questions about its measurement in solutions without supporting salts. This book illustrates the variety of redox reactions in its examination of the importance of redox molecules in the development of new electrical energy storage devices.
    Schlagwort(e): Chemistry ; thema EDItEUR::P Mathematics and Science::PN Chemistry::PNR Physical chemistry::PNRH Electrochemistry and magnetochemistry
    Sprache: Englisch
    Format: image/jpeg
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 15
    facet.materialart.
    Unbekannt
    IntechOpen | IntechOpen
    Publikationsdatum: 2024-04-05
    Beschreibung: We are living in a critical time, both for humanity and the planet, which has led us to look for more sustainable formulas to interact with the environment. One of the important changes in the design and operation of chemical processes is the search for environmentally friendly technologies. Supercritical carbon dioxide has been revealed as a promising environmentally friendly solvent that is energy efficient, selective and capable of reducing waste, making it a promising alternative to conventional organic solvents. However, reliable and versatile mathematical models of phase equilibrium thermodynamics are needed for the use of supercritical carbon dioxide in process design and viability studies. This book reviews experimental procedures for obtaining high-pressure phase equilibria data and describes the phase diagrams of binary mixtures and some thermodynamic models capable of determining the conditions of phase equilibria at high pressures. These concepts are applied to the components of the transesterification reaction of rac-2-pentanol with a vinyl ester, which is important in the pharmaceutical industry because (S)-2-pentanol can be obtained as a reaction product. This product is a key intermediate in the synthesis of drugs against Alzheimer’s disease.
    Schlagwort(e): Chemistry ; thema EDItEUR::P Mathematics and Science::PN Chemistry::PNR Physical chemistry
    Sprache: Englisch
    Format: image/jpeg
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 16
    facet.materialart.
    Unbekannt
    IntechOpen | IntechOpen
    Publikationsdatum: 2024-04-05
    Beschreibung: In recent decades, artificial porous structures have attracted increasing enthusiasm from researchers inspired by the fascinating molecular pores in nature and their unique biological functions. Although substantial achievements in porous materials have been realized, the construction of topologically designed pores is still challenging. Recently, the emergence of covalent organic frameworks (COFs), which are constructed based on organic and polymer chemistry, has made it possible to design artificial pores with controlled pore size, topology and interface properties. COFs are crystalline porous materials constructed by the precise reticulation of organic building blocks via dynamic covalent bonds. Distinct from non-covalent interactions which tend to produce isostructures, covalent bonds enable accurate pore design owing to their predetermined reaction pathways. In addition, the appropriate polycondensation of organic building units enables the formation of extended two-dimensional (2D) and three-dimensional (3D) polymer architectures with periodically ordered skeletons and well-defined pores. With their large surface area, tailorable structures, and tunable chemistry, COFs are regarded as potentially superior candidates for various applications including catalysis, energy storage and conversion, mass transport and biotechnology. This book examines the historic achievement of COFs, providing clear and comprehensive guidance for researchers on their structural design, synthetic protocols and functional exploration.
    Schlagwort(e): Chemistry ; thema EDItEUR::P Mathematics and Science::PN Chemistry::PNN Organic chemistry
    Sprache: Englisch
    Format: image/jpeg
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 17
    facet.materialart.
    Unbekannt
    IntechOpen | IntechOpen
    Publikationsdatum: 2024-04-05
    Beschreibung: Fluoride covers a continuum of topics that are frequently studied in the broad area of fluoride (F) research. It provides an overview of the primary sources of environmental fluoride in typical high-fluoride environments and demonstrates the transitions and transformations that emerge and culminate in hydro-geochemical interactions that result in fluoride-fouling of large portions of the world’s water and agricultural resources. This way, the book pinpoints the connection between F enrichment of water sources and the prevalence of endemic fluorosis in certain areas of the world. In order to contribute to a better understanding of the global fluoride problem, new fluoride detection and quantification technologies are proposed with an in-depth analysis of emerging trends in the use of portable user-friendly devices in point-of-use measurements of water fluoride. This has been presented against the backdrop of a robust overview of traditional fluoride quantification methodologies that are still in wide application among the scientific communities. In addressing fluoride toxicities, which are not limited to dental and skeletal dilapidations, the authors have explored the role of natural antioxidants in ameliorating physiological fluoride-induced noxious effects in mammalian systems. Nonetheless, since community dependence on high-fluoride water due to a lack of alternative clean water sources remains to be the principal pathway of human fluoride over-exposure, a review chapter on F mitigation techniques applied all over the world is incorporated aiming at providing a succinct overview of water defluoridation techniques and strategies being used to combat the impacts of human F overexposure around the globe. Since every cloud has a silvery lining, the possibility of using ammonium fluorides as a novel reagent in mineral processing has been considered convenient industrial fluorinating agents, which present the possibility of complete regeneration that is not afforded by the reagents presently used in decomposing silicon component of the ores.
    Schlagwort(e): Chemistry ; thema EDItEUR::P Mathematics and Science::PN Chemistry::PNK Inorganic chemistry
    Sprache: Englisch
    Format: image/jpeg
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 18
    facet.materialart.
    Unbekannt
    IntechOpen | IntechOpen
    Publikationsdatum: 2024-04-05
    Beschreibung: This book discusses the chemistry and applications of pyridine derivatives. The library of pyridine derivatives is growing steadily with numerous synthetic analogues already described and the identification of new, naturally occurring pyridine-based compounds. The book includes ten chapters organized into two parts. The first part focuses on the numerous types of reactions that arise from pyridine derivatives. The second part examines the pharmaceutical applications of pyridine derivatives as well as their usefulness as sensors for metal cations and extracting agents for platinum group metals.
    Schlagwort(e): Chemistry ; thema EDItEUR::P Mathematics and Science::PN Chemistry::PNN Organic chemistry
    Sprache: Englisch
    Format: image/jpeg
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 19
    facet.materialart.
    Unbekannt
    IntechOpen | IntechOpen
    Publikationsdatum: 2024-04-05
    Beschreibung: The book discusses multiple issues associated with modern dosimetry in physics and treatment planning and how investigators from diverse world centers and institutions approach problem-solving in these important areas. It examines topics including pretreatment validation and factors affecting reference dosimetry. It also addresses unique issues affecting pediatric populations as well as the modern role of thermoluminescence validation. Several chapters discuss intensity modulation, including defining modern problems associated with both treatment planning and the definition of tumor and normal tissue contours. Furthermore, the book examines the role of imaging as both a vehicle to define tumor targets and normal tissue as well as a tool for dose validation.
    Schlagwort(e): Chemistry ; thema EDItEUR::P Mathematics and Science::PN Chemistry::PNR Physical chemistry::PNRL Nuclear chemistry, photochemistry and radiation
    Sprache: Englisch
    Format: image/jpeg
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 20
    facet.materialart.
    Unbekannt
    IntechOpen | IntechOpen
    Publikationsdatum: 2024-04-05
    Beschreibung: The book comprises 14 chapters covering all the issues related to water desalination. These chapters emphasize the relationship between problems encountered with the use of feed water, the processes developed to address them, the operation of the required plants and solutions actually implemented. This compendium will assist designers, engineers and investigators to select the process and plant configuration that are most appropriate for the particular feed water to be used, for the geographic region considered, as well as for the characteristics required of the treated water produced. This survey offers a comprehensive, hierarchical and logical assessment of the entire desalination industry. It starts with the worldwide scarcity of water and energy, continues with the thermal - and membrane-based processes and, finally, presents the design and operation of large and small desalination plants. As such, it covers all the scientific, technological and economical aspects of this critical industry, not disregarding its environmental and social points of view. One of InTech's books has received widespread praise across a number of key publications. Desalination, Trends and Technologies (Ed. Schorr, M. 2011) has been reviewed in Corrosion Engineering, Science & Technology – the official magazine for the Institute of Materials, Minerals & Mining, and Taylor & Francis's Desalination Publications. Praised for its “multi-faceted content [which] contributes to enrich it,” and described as “an essential companion...[that] enables the reader to gain a deeper understanding of the desalination industry,” this book is testament to the quality improvements we have been striving towards over the last twelve months.
    Schlagwort(e): Chemistry ; thema EDItEUR::P Mathematics and Science::PN Chemistry::PNF Analytical chemistry
    Sprache: Englisch
    Format: image/jpeg
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 21
    Publikationsdatum: 2024-04-05
    Beschreibung: The Global Methane Initiative (GMI) is a voluntary international partnership that promotes methane recovery and reuse activities in developing and transition economies. The U.S. Department of State requested an evaluation of the activities and outcomes supported in whole or in part by its contributions to GMI to gauge its value added to the program.
    Schlagwort(e): Physics ; Environmental Science ; Chemistry ; thema EDItEUR::P Mathematics and Science::PN Chemistry ; thema EDItEUR::T Technology, Engineering, Agriculture, Industrial processes::TQ Environmental science, engineering and technology ; thema EDItEUR::R Earth Sciences, Geography, Environment, Planning::RB Earth sciences::RBP Meteorology and climatology
    Sprache: Englisch
    Format: image/jpeg
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 22
    facet.materialart.
    Unbekannt
    IntechOpen | IntechOpen
    Publikationsdatum: 2024-04-05
    Beschreibung: Progress in agricultural, biomedical and industrial applications' is a compilation of recent advances and developments in gas chromatography and its applications. The chapters cover various aspects of applications ranging from basic biological, biomedical applications to industrial applications. Book chapters analyze new developments in chromatographic columns, microextraction techniques, derivatisation techniques and pyrolysis techniques. The book also includes several aspects of basic chromatography techniques and is suitable for both young and advanced chromatographers. It includes some new developments in chromatography such as multidimensional chromatography, inverse chromatography and some discussions on two-dimensional chromatography. The topics covered include analysis of volatiles, toxicants, indoor air, petroleum hydrocarbons, organometallic compounds and natural products. The chapters were written by experts from various fields and clearly assisted by simple diagrams and tables. This book is highly recommended for chemists as well as non-chemists working in gas chromatography.
    Schlagwort(e): Chemistry ; thema EDItEUR::P Mathematics and Science::PN Chemistry::PNF Analytical chemistry
    Sprache: Englisch
    Format: image/jpeg
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 23
    facet.materialart.
    Unbekannt
    IntechOpen | IntechOpen
    Publikationsdatum: 2024-04-05
    Beschreibung: This book discusses electrocatalysis and electrocatalysts for energy, water electrolysis, water treatment, CO2 conversion, and green chemistry. It reviews various electrocatalysts and their properties and electrochemical performances. The first section of the book covers topics in direct alcohol fuel cells including Pt-based electrocatalysts as non-carbon electrode support materials and the development of electrocatalysts for direct methanol fuel cells. The second section of the book covers various topics in electrocatalysis and electrocatalysts for a cleaner environment, including electrocatalysts for the conversion of CO2 to valuable products and SYNGAS, electrocatalysts for water electrolysis, and much more.
    Schlagwort(e): Chemistry ; thema EDItEUR::P Mathematics and Science::PN Chemistry::PNR Physical chemistry::PNRH Electrochemistry and magnetochemistry
    Sprache: Englisch
    Format: image/jpeg
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 24
    facet.materialart.
    Unbekannt
    MDPI - Multidisciplinary Digital Publishing Institute
    Publikationsdatum: 2023-06-23
    Beschreibung: The aim of this second Eng Special Issue is to collect experimental and theoretical re-search relating to engineering science and technology. The general topics of Eng are as follows: electrical, electronic and information engineering; chemical and materials engineering; energy engineering; mechanical and automotive engineering; industrial and manufacturing engineering; civil and structural engineering; aerospace engineering; biomedical engineering; geotechnical engineering and engineering geology; and ocean and environmental engineering. Therefore, the following editorial is a selection of representative works of these topics.
    Schlagwort(e): &nbsp ; Environment Management ; Environmental Engineering ; Chemical Engineering ; Materials Engineering&nbsp ; bic Book Industry Communication::T Technology, engineering, agriculture::TB Technology: general issues ; bic Book Industry Communication::T Technology, engineering, agriculture::TB Technology: general issues::TBX History of engineering & technology
    Sprache: Englisch
    Format: image/jpeg
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 25
    facet.materialart.
    Unbekannt
    IntechOpen | IntechOpen
    Publikationsdatum: 2024-04-05
    Beschreibung: Surfactants are ubiquitous and have applications in diverse areas, including food, cosmetics, detergents, lubricants, enhanced oil recovery (EOR), and targeted drug delivery systems. Their wide diversity of applications owes to their unique structure, namely, a hydrophilic and a hydrophobic group present in the same molecule. Although most surfactants used industrially are synthetic, there is a growing need for natural surfactants, as the latter is obtainable from renewable sources and are less toxic and highly biodegradable in contrast to their synthetic counterparts. This book is a compilation of interesting articles by various experts that cover various applications of both synthetic and natural surfactants.
    Schlagwort(e): Chemistry ; thema EDItEUR::P Mathematics and Science::PN Chemistry::PNR Physical chemistry::PNRC Colloid chemistry
    Sprache: Englisch
    Format: image/jpeg
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 26
    facet.materialart.
    Unbekannt
    IntechOpen | IntechOpen
    Publikationsdatum: 2024-04-05
    Beschreibung: The chemical sensor plays an essential role in the fields of environmental conservation and monitoring, disaster and disease prevention, and industrial analysis. A typical chemical sensor is a device that transforms chemical information in a selective and reversible way, ranging from the concentration of a specific sample component to total composition analysis, into an analytically useful signal. Much research work has been performed to achieve a chemical sensor with such excellent qualities as quick response, low cost, small size, superior sensitivity, good reversibility and selectivity, and excellent detection limit. This book introduces the latest advances on chemical sensors. It consists of 15 chapters composed by the researchers active in the field of chemical sensors, and is divided into 5 sections according to the classification following the principles of signal transducer. This collection of up-to-date information and the latest research progress on chemical sensor will provide valuable references and learning materials for all those working in the field of chemical sensors.
    Schlagwort(e): Chemistry ; thema EDItEUR::P Mathematics and Science::PN Chemistry::PNF Analytical chemistry
    Sprache: Englisch
    Format: image/jpeg
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 27
    facet.materialart.
    Unbekannt
    IntechOpen | IntechOpen
    Publikationsdatum: 2024-04-05
    Beschreibung: Distillation is an important separation technique that has been used for many centuries to exploit the volatility differences between components in a mixture. The distillation process has many variations and applications. This book includes two sections on desalination and reactive distillation. It discusses desalination in the processes of solar and membrane distillation, with a focus on the reduction of energy costs to obtain potable water. It also discusses reactive distillation, which can be used in some cases to reduce the power duty in the separation process by using the reaction heat directly in the separation. The book includes cases of mathematical modeling, simulation, and optimization of the distillation process.
    Schlagwort(e): Chemistry ; thema EDItEUR::P Mathematics and Science::PN Chemistry::PNF Analytical chemistry
    Sprache: Englisch
    Format: image/jpeg
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 28
    facet.materialart.
    Unbekannt
    IntechOpen | IntechOpen
    Publikationsdatum: 2024-04-05
    Beschreibung: Cyclodextrins (CDs) have attracted great interest from the research community as well as industries in an array of sectors because of their unique structural features. This book provides a comprehensive overview of CDs, beginning with their historical background. Chapters address such topics as the structure and physiochemical properties of CDs, advancements in the field, and potential applications of these materials in fields such as drug delivery and sensing. This book reveals new frontiers in the CD world and is a useful resource for organic, analytical, and supramolecular chemists as well as scientists engaged in biological and material sciences.
    Schlagwort(e): Chemistry ; thema EDItEUR::P Mathematics and Science::PN Chemistry::PNN Organic chemistry::PNNP Polymer chemistry
    Sprache: Englisch
    Format: image/jpeg
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 29
    facet.materialart.
    Unbekannt
    IntechOpen | IntechOpen
    Publikationsdatum: 2024-04-05
    Beschreibung: The book presents a comprehensive overview of sorption, which is a multi-parametric separation process. It is extensively used in the removal of various pollutants from the tertiary stage of wastewater treatment, from leachates, etc. It discusses fundamental points of the technique as well as kinetic theories and isotherms. It also examines the synthesis and characterizations of all studied adsorbent materials to find their paths of sorption. Finally, it highlights the importance of having a cost-estimation plan for the synthesis of sorbent materials as well as predictions for their reusability.
    Schlagwort(e): Chemistry ; thema EDItEUR::P Mathematics and Science::PN Chemistry::PNR Physical chemistry::PNRX Surface chemistry and adsorption
    Sprache: Englisch
    Format: image/jpeg
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 30
    facet.materialart.
    Unbekannt
    IntechOpen | IntechOpen
    Publikationsdatum: 2024-04-05
    Beschreibung: Carotenoids are natural and versatile secondary metabolites, most of them showing colours that vary from yellow to red. They are widespread among living beings where they are involved in many biological roles reporting beneficial actions. To date, more than 750 carotenoids have been described in nature. Humans cannot synthesize carotenoids de novo, thus they are mainly obtained through diet. In fact, carotenoids are consistently found in tissues or biological fluids where they play a beneficial decreasing the risk of developing some diseases.During the last half-century, significant advances in carotenoids research have been made. This book highlights new perspectives and applications of carotenoids including characterization and isolation of new compounds (including rare carotenoids), their production at a mid-large scale (involving new innovative approaches), and uses of carotenoids in different biotechnological fields like food science, biomedicine, and cosmetics.
    Schlagwort(e): Chemistry ; thema EDItEUR::P Mathematics and Science::PN Chemistry::PNN Organic chemistry
    Sprache: Englisch
    Format: image/jpeg
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 31
    facet.materialart.
    Unbekannt
    IntechOpen | IntechOpen
    Publikationsdatum: 2024-04-05
    Beschreibung: Infrared Spectroscopy - Perspectives and Applications is a compendium of contributions from experts in the field of infrared (IR) spectroscopy. This assembly of investigations and reviews provides a comprehensive overview of the fundamentals as well as the groundbreaking applications in the field. Chapters discuss IR spectroscopy applications in the food and biomedicine sectors and for measuring transport through polymer membranes, characterizing lignocellulosic biomasses, detecting adulterants, and characterizing enamel surface advancements. This book is an invaluable resource and reference for students, researchers, and other interested readers.
    Schlagwort(e): Chemistry ; thema EDItEUR::P Mathematics and Science::PN Chemistry::PNF Analytical chemistry::PNFS Spectrum analysis, spectrochemistry, mass spectrometry
    Sprache: Englisch
    Format: image/jpeg
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 32
    Publikationsdatum: 2023-03-08
    Beschreibung: © The Author(s), 2022. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in LeClerc, H., Tompsett, G., Paulsen, A., McKenna, A., Niles, S., Reddy, C., Nelson, R., Cheng, F., Teixeira, A., & Timko, M. Hydroxyapatite catalyzed hydrothermal liquefaction transforms food waste from an environmental liability to renewable fuel. IScience, 25(9), (2022): 104916, https://doi.org/10.1016/j.isci.2022.104916.
    Beschreibung: Food waste is an abundant and inexpensive resource for the production of renewable fuels. Biocrude yields obtained from hydrothermal liquefaction (HTL) of food waste can be boosted using hydroxyapatite (HAP) as an inexpensive and abundant catalyst. Combining HAP with an inexpensive homogeneous base increased biocrude yield from 14 ± 1 to 37 ± 3%, resulting in the recovery of 49 ± 2% of the energy contained in the food waste feed. Detailed product analysis revealed the importance of fatty-acid oligomerization during biocrude formation, highlighting the role of acid-base catalysts in promoting condensation reactions. Economic and environmental analysis found that the new technology has the potential to reduce US greenhouse gas emissions by 2.6% while producing renewable diesel with a minimum fuel selling price of $1.06/GGE. HAP can play a role in transforming food waste from a liability to a renewable fuel.
    Beschreibung: This work was funded by the DOE Bioenergy Technology Office (DE-EE0008513), a DOE DBIR (DE-SC0015784) and the MassCEC. The authors thank WenWen Yao, Department of Environmental Science at WPI, for TOC analysis, Mainstream Engineering for heating value characterization of the oil and solid samples, Wei Fan for assistance in obtaining SEM images and, Julia Martin and Ronald Grimm for their assistance in collecting XPS data, and Jeffrey R. Page for his assistance with oil upgrading and analysis. HOL was partially funded for this work by NSF Graduate Research Fellowship award number 2038257. A portion of this work was performed at the National High Magnetic Field Laboratory Ion Cyclotron Resonance user facility, which is supported by the NSF Division of Materials Research and Division of Chemistry through DMR 16-44779 and the State of Florida.
    Schlagwort(e): Chemistry ; Chemical engineering ; Catalysis
    Repository-Name: Woods Hole Open Access Server
    Materialart: Article
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 33
    Publikationsdatum: 2024-04-05
    Beschreibung: Chemiebezogene Kompetenzen werden bereits im Sachunterricht der Grundschule entwickelt und sollen im Chemieunterricht der Sekundarstufe I aufgegriffen und weiterentwickelt werden. Ziel dieser Studie war es, die chemiebezogenen Kompetenzen der Schülerinnen und Schüler in der Übergangsphase zwischen Sachunterricht und Chemieunterricht zu analysieren. In einer Ergänzungsstudie wurden zusätzlich sowohl die Auswirkungen der Schulschließungen aufgrund der SARS-CoV-II Pandemie auf die Kompetenzen der Schülerinnen und Schüler als auch der Einfluss einer veränderten Testadministration untersucht. Insgesamt wurden die Kompetenzen von 2262 Lernenden der Jahrgangsstufen 5 bis 9 zu drei Messzeitpunkten analysiert. Die Ergebnisse zeigen, dass die chemiebezogenen Kompetenzen sowohl zum Ende der Grundschulzeit als auch zu Beginn des Chemieunterrichts über alle Kompetenzbereiche hinweg sehr heterogen ausfallen. Dennoch sind sie zu Beginn des Chemieunterrichts in einigen Kompetenzbereichen höher ausgeprägt als zum Ende der Grundschulzeit. Nach den pandemiebedingten Schulschließungen waren die Kompetenzen ähnlich ausgeprägt wie in den gleichen Jahrgangsstufen vor den Schulschließungen. Eine während der Schulschließungen notwendige Bearbeitung der Testhefte von zu Hause aus führte vor allem bei den jüngeren Schülerinnen und Schülern zu besseren Testergebnissen als die Bearbeitung in der Schule. Um die Entwicklung chemiebezogener Kompetenzen in der Übergangsphase zu optimieren, sollte der Erwerb dieser Kompetenzen bereits im Sachunterricht einheitlicher gestaltet werden.
    Schlagwort(e): Science ; Chemistry ; Education ; thema EDItEUR::P Mathematics and Science::PN Chemistry ; thema EDItEUR::J Society and Social Sciences::JN Education
    Sprache: Deutsch
    Format: image/jpeg
    Format: image/jpeg
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 34
    facet.materialart.
    Unbekannt
    Logos Verlag Berlin | Logos Verlag Berlin
    Publikationsdatum: 2024-04-05
    Beschreibung: In 2005, the hybrid model was published by Prof. H.-D. Alber and Prof. P. Zhu as an alternative to the Allen-Cahn model for the description of phase field transformations. With low interfacial energy, it is more efficient, since the resolution of the diffuse interface is numerically broader for the same solution accuracy and allows coarser meshing. The solutions of both models are associated with energy minimisation and in this work the error terms introduced in the earlier publications are discussed and documented using one and two dimensional numerical simulations. In the last part of this book, phase field problems, initially not coupled with material equations, are combined with linear elasticity and, after simple introductory examples, a growing martensitic inclusion is simulated and compared with literature data. In addition to the confirmed numerical advantage, another phenomenon not previously described in the literature is found: with the hybrid model, in contrast to the examples calculated with the Allen-Cahn model, an inclusion driven mainly by curvature energy does not disappear completely. The opposite problem prevents inclusions from growing from very small initial configurations, but this fact can be remedied by a very finely chosen diffuse interface width and by analysing and adjusting the terms that generate the modelling errors. The last example shows that the hybrid model can be used with numerical advantages despite the above mentioned peculiarities.
    Schlagwort(e): Science ; Chemistry ; Mathematics ; Science ; Physics ; thema EDItEUR::P Mathematics and Science::PN Chemistry ; thema EDItEUR::P Mathematics and Science::PB Mathematics ; thema EDItEUR::P Mathematics and Science::PH Physics
    Sprache: Englisch
    Format: image/jpeg
    Format: image/jpeg
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 35
    facet.materialart.
    Unbekannt
    Logos Verlag Berlin | Logos Verlag Berlin
    Publikationsdatum: 2024-04-05
    Beschreibung: Das selbstgesteuerte Experimentieren ist laut den nationalen Bildungsstandards sowie den Lehrplänen im Fach Chemie ein wichtiger Bestandteil der naturwissenschaftlichen Schulbildung. Offene Experimentierformen sind jedoch wenig etabliert. Um das selbstgesteuerte Experimentieren in die Unterrichtspraxis zu implementieren, wurde im Rahmen dieses Forschungsprojekts eine eintägige Lehrkräftefortbildung zur Konzeption von selbstgesteuerten Experimenten im Chemieunterricht durchgeführt. Dazu wurde ein literaturbasiertes Strukturierungskonzept entwickelt, mit dem die Lehrkräfte kochbuchartige Schulversuche zu selbstgesteuerten und kompetenzorientierten Experimenten mit beliebigen Öffnungsgraden modifizieren können. Begleitend zur Fortbildung wurde im Prä-Post-Follow-Up-Design das fachdidaktische Wissen der Teilnehmenden hinsichtlich der Planung von selbstgesteuerten Experimenten empirisch überprüft. Zur Erfassung dieses Konstrukts wurde ein neues Messinstrument literaturbasiert entwickelt und die Güte des Messinstruments evaluiert. Die Auswertungen zeigen, dass die Fortbildung hinsichtlich des fachdidaktischen Wissens der Lehrkräfte kurz- sowie langfristig lernförderlich ist und die Fortbildung von den Teilnehmenden positiv bewertet wird. Die Reliabilitätsanalyse sowie die Validierungsstudie zeigen, dass der Test sowohl reliabel als auch valide ist. In Folgestudien könnte die langfristige Verhaltensänderung der Lehrkräfte bezüglich der Implementierung des selbstgesteuerten Experimentierens in den Unterricht untersucht werden.
    Schlagwort(e): Science ; Chemistry ; Science ; Education ; thema EDItEUR::P Mathematics and Science::PN Chemistry ; thema EDItEUR::P Mathematics and Science::PD Science: general issues ; thema EDItEUR::J Society and Social Sciences::JN Education
    Sprache: Deutsch
    Format: image/jpeg
    Format: image/jpeg
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 36
    facet.materialart.
    Unbekannt
    De Gruyter | De Gruyter
    Publikationsdatum: 2024-04-05
    Beschreibung: The essential principles of green chemistry are the use of renewable raw materials, highly efficient catalysts and green solvents linked with energy efficiency and process optimization in real-time. Experts from different fields show, how to examine all levels from the molecular elementary steps up to the design and operation of an entire plant for developing novel and efficient production processes.
    Schlagwort(e): Process Engineering ; Chemical Engineering ; Technical Chemistry ; thema EDItEUR::P Mathematics and Science::PN Chemistry ; thema EDItEUR::R Earth Sciences, Geography, Environment, Planning::RN The environment ; thema EDItEUR::R Earth Sciences, Geography, Environment, Planning::RN The environment::RNU Sustainability ; thema EDItEUR::T Technology, Engineering, Agriculture, Industrial processes::TD Industrial chemistry and manufacturing technologies::TDC Industrial chemistry and chemical engineering ; thema EDItEUR::T Technology, Engineering, Agriculture, Industrial processes::TG Mechanical engineering and materials::TGM Materials science ; thema EDItEUR::T Technology, Engineering, Agriculture, Industrial processes::TQ Environmental science, engineering and technology
    Sprache: Englisch
    Format: image/jpeg
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 37
    facet.materialart.
    Unbekannt
    Logos Verlag Berlin | Logos Verlag Berlin
    Publikationsdatum: 2024-04-05
    Beschreibung: Konsumgüter werden beispielsweise mit Slogans wie "Gut in Bio. Schlecht in Chemie." beworben. Dabei wird intendiert, sich gezielt von "Chemie" abzugrenzen und sich das positive Bild von "Natur" zu Nutze zu machen. Dies prägt die öffentliche Meinung und trägt zu einer antagonistisch-wertenden Sicht von "Chemie" und "Natur" bei. Dass Chemie als Naturwissenschaft der Beschreibung der Natur dient, um deren Stoffe und Stoffumwandlungen zu erklären, ist dem Laien selten bewusst. Chemie findet überall statt, insbesondere in der Natur! Genau an diesem Punkt setzt das Unterrichtskonzept "Chemie Pur - Unterrichten in der Naturglqq an. Ziel ist es, im Freiland, mit direkt vor Ort gewonnenen Naturstoffen, Umweltprozesse experimentell zu erarbeiten. Die projektbegleitende Evaluationsstudie stellte sich der Forschungsfrage, wie sich das Unterrichtskonzept auf das Fach- und Sachinteresse, auf die Naturverbundenheit sowie auf die Einstellung zu Chemie und Natur von Schülerinnen und Schülern der Sekundarstufe II auswirkt. Die Auswertung der Fragebogenergebnisse mit latenten Veränderungsmodellen haben gezeigt, dass die Intervention im Freiland das inhaltsbezogene Sachinteresse steigert und die Einstellung zu Chemie und Natur positiv beeinflusst sowie ein erhöhten Fachwissenszuwachs ermöglicht. Die gewonnenen Erkenntnisse können die Grundlage für die Entwicklung und Evaluation von good-practice-Ansätzen naturwissenschaftlicher Lernsituationen bilden. Das Unterrichtskonzept Chemie Pur leistet zudem einen Beitrag im Bereich Outdoor Education, um den Antagonismus von Chemie und Natur zu verringern.
    Schlagwort(e): Science ; Chemistry ; Science ; Education ; thema EDItEUR::P Mathematics and Science::PN Chemistry ; thema EDItEUR::P Mathematics and Science::PD Science: general issues ; thema EDItEUR::J Society and Social Sciences::JN Education
    Sprache: Deutsch
    Format: image/jpeg
    Format: image/jpeg
    Format: image/jpeg
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 38
    facet.materialart.
    Unbekannt
    The MIT Press | The MIT Press
    Publikationsdatum: 2024-03-27
    Beschreibung: The original 1818 text of Mary Shelley's classic novel, with annotations and essays highlighting its scientific, ethical, and cautionary aspects. Mary Shelley's Frankenstein has endured in the popular imagination for two hundred years. Begun as a ghost story by an intellectually and socially precocious eighteen-year-old author during a cold and rainy summer on the shores of Lake Geneva, the dramatic tale of Victor Frankenstein and his stitched-together creature can be read as the ultimate parable of scientific hubris. Victor, “the modern Prometheus,” tried to do what he perhaps should have left to Nature: create life. Although the novel is most often discussed in literary-historical terms—as a seminal example of romanticism or as a groundbreaking early work of science fiction—Mary Shelley was keenly aware of contemporary scientific developments and incorporated them into her story. In our era of synthetic biology, artificial intelligence, robotics, and climate engineering, this edition of Frankenstein will resonate forcefully for readers with a background or interest in science and engineering, and anyone intrigued by the fundamental questions of creativity and responsibility. This edition of Frankenstein pairs the original 1818 version of the manuscript—meticulously line-edited and amended by Charles E. Robinson, one of the world's preeminent authorities on the text—with annotations and essays by leading scholars exploring the social and ethical aspects of scientific creativity raised by this remarkable story. The result is a unique and accessible edition of one of the most thought-provoking and influential novels ever written. Essays by Elizabeth Bear, Cory Doctorow, Heather E. Douglas, Josephine Johnston, Kate MacCord, Jane Maienschein, Anne K. Mellor, Alfred Nordmann
    Schlagwort(e): science fiction ; gothic ; horror ; European ; British ; literature ; fiction ; cautionary tale ; STEM ; science ; bioethics ; classic ; bicentennial ; Josephine Johnston ; Cory Doctorow ; Jane Maienschein ; Kate MacCord ; Alfred Nordmann ; Elizabeth Bear ; Anne K. Mellor ; Heather E. Douglas ; Frankenstein ; Creature ; Monster ; Mary Shelley ; Makers ; women in science ; science and anti-science ; values in science ; responsible innovation ; Industrial Revolution ; Mary Wollstonecraft ; William Godwin ; Percy Bysshe Shelley ; Galvanism ; Mount Tambora ; Myths ; Two Cultures ; epistolary novel ; Victor Frankenstein ; Geneva ; Prometheus ; Arctic ; Lord Byron ; John Polidori ; ghost stories ; Revisions ; Electricity ; Lightning ; Vitalism ; Chemistry ; Extinction ; Magnetism ; Moral responsibility ; Legal responsibility ; Social responsibility ; Consequences ; Obligations ; Ethics ; Maker Culture ; DIY ; Technology Adjacent Possible ; Facebook ; Surveillance ; Aristotle ; Fetal development ; Epigenesis ; Embryo ; Person ; Technoscience ; Alchemy ; uncanny valley ; animation ; complexity ; Morality ; Monstrosity ; Christianity ; Otherness ; Gender ; Nature ; Domestic Affections ; Women ; Sexuality ; Technical Sweetness ; Los Alamos ; Trinity Test ; Scientific Responsibility ; Nuclear Weapons ; adjacent possible ; synthetic biology ; robotics ; thema EDItEUR::F Fiction and Related items::FB Fiction: general and literary::FBC Classic fiction: general and literary ; thema EDItEUR::F Fiction and Related items::FL Science fiction::FLC Classic science fiction
    Sprache: Englisch
    Format: image/jpeg
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 39
    facet.materialart.
    Unbekannt
    Logos Verlag Berlin | Logos Verlag Berlin
    Publikationsdatum: 2024-04-05
    Beschreibung: When auralizing moving sound sources in Virtual Reality (VR) environments, the two main input parameters are the location and radiated signal of the source. An array measurement-based model is developed to characterize moving sound sources regarding the two parameters in this thesis. This model utilizes beamforming, i.e. delay and sum beamforming (DSB) and compressive beamforming (CB) to obtain the locations and signals of moving sound sources. A spiral and a pseudorandom microphone array are designed for DSB and CB, respectively, to yield good localization ability and meet the requirement of CB. The de-Dopplerization technique is incorporated in the time-domain DSB to address moving source problems. Time-domain transfer functions (TDTFs) are calculated in terms of the spatial locations within the steering window of the moving source. TDTFs then form the sensing matrix of CB, thus allowing CB to solve moving source problem. DSB and CB are further extended to localize moving sound sources, and the reconstructed signals from the beamforming outputs are investigated to obtain the source signals. Moreover, localization and signal reconstruction are evaluated through varying parameters in the beamforming procedures, i.e. steering position, steering window length and source speed for a moving periodic signal using DSB, and regularization parameter, signal to noise ratio (SNR), steering window length, source speed, array to source motion trajectory and mismatch for a moving engine signal using CB. The parameter studies show guidelines of parameter selection based on the given situations in this thesis for modeling moving source using beamforming. Both algorithms are able to reconstruct the moving signals in the given scenarios. Although CB outperforms DSB in terms of signal reconstruction under particular conditions, the localization abilities of the two algorithms are quite similar. The practicability of the model has been applied on pass-by measurements of a moving loudspeaker using the designed arrays, and the results can match the conclusions drawn above from simulations. Finally, a framework on how to apply the model for moving source auralization is proposed.
    Schlagwort(e): Science ; Chemistry ; Technology & Engineering ; Construction ; Technology & Engineering ; thema EDItEUR::P Mathematics and Science::PN Chemistry ; thema EDItEUR::T Technology, Engineering, Agriculture, Industrial processes::TN Civil engineering, surveying and building::TNK Building construction and materials ; thema EDItEUR::T Technology, Engineering, Agriculture, Industrial processes::TB Technology: general issues
    Sprache: Englisch
    Format: image/jpeg
    Format: image/jpeg
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 40
    Publikationsdatum: 2024-04-05
    Beschreibung: Neuere Erkenntnisse zum Umsatzverhalten an Dieseloxidationskatalysatoren (DOCs) zeigen, dass das Umsatzverhalten von Schadstoffen vom Oxidationsgrad der verwendeten Edelmetallkatalysatoren abhängen kann. Dabei wird deutlich, dass sich der Oxidationsgrad bei typischen Abgaszusammensetzungen langsam und reversibel mit der Katalysatortemperatur ändert. Das kann bei periodischen Katalysatortemperaturänderungen zu einem ausgeprägten Hystereseverhalten führen. Bisherige Ergebnisse liegen insbesondere zum Verhalten der NO-Oxidation an Platin-Katalysatoren vor. Ziel der vorliegenden Arbeit ist es daher, die Untersuchungen auf seriennahe Pd- und PtPd-Mischkatalysatoren sowie auf andere abgastypische Schadstoffe, wie CO und Kohlenwasserstoffe, zu erweitern und dabei auch den Einfluss der Katalysatoralterung zu erfassen. Es wurde ein globalkinetisches Modell entwickelt und an die experimentellen Befunde angepasst. Dabei zeigte sich, dass es in der Regel möglich ist, das Umsatzverhalten bei reinen Pt- und Pd-Katalysatoren mit diesem örtlich eindimensionalen, makrokinetischen Zweiphasenmodell zutreffend zu beschreiben, wohingegen das Verhalten auf Pt/Pd-Mischkatalysatoren weniger gut simuliert werden kann. Dies ist vermutlich auf die heterogene Struktur der Pt/Pd-legierten Partikel zurückzuführen.
    Schlagwort(e): Science ; Chemistry ; Technology & Engineering ; Chemical & Biochemical ; thema EDItEUR::P Mathematics and Science::PN Chemistry ; thema EDItEUR::T Technology, Engineering, Agriculture, Industrial processes::TD Industrial chemistry and manufacturing technologies::TDC Industrial chemistry and chemical engineering
    Sprache: Deutsch
    Format: image/jpeg
    Format: image/jpeg
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 41
    facet.materialart.
    Unbekannt
    Taylor & Francis | CRC Press
    Publikationsdatum: 2024-03-31
    Beschreibung: Hydroxyapatite coatings are of great importance in the biological and biomedical coatings fields, especially in the current era of nanotechnology and bioapplications. With a bonelike structure that promotes osseointegration, hydroxyapatite coating can be applied to otherwise bioinactive implants to make their surface bioactive, thus achieving faster healing and recovery. In addition to applications in orthopedic and dental implants, this coating can also be used in drug delivery. Hydroxyapatite Coatings for Biomedical Applications explores developments in the processing and property characterization and applications of hydroxyapatite to provide timely information for active researchers and newcomers alike. In eight carefully reviewed chapters, hydroxyapatite experts from the United States, Japan, Singapore, and China present the latest on topics ranging from deposition processes to biomedical applications in implants and drug delivery. This book discusses: Magnetron sputtering and electrochemical deposition The modification of hydroxyapatite properties by sol–gel deposition to incorporate other elements found in natural bones, such as zinc, magnesium, and fluorine The use of pure hydroxyapatite in drug delivery applications The growth or self-assembly of hydroxyapatite on shape memory alloy Hydroxyapatite composite coatings—with carbon nanotubes, titanium dioxide (TiO2), and others—on the titanium alloy Offering valuable insights and a wealth of data, including numerous tables and figures, this is a rich source of information for research on hydroxyapatite coatings. Each chapter also covers material that provides an accessible stepping stone for those who are new to the field.
    Schlagwort(e): Pre-clinical medicine: basic sciences ; Chemistry ; Materials science ; thema EDItEUR::M Medicine and Nursing::MF Pre-clinical medicine: basic sciences ; thema EDItEUR::P Mathematics and Science::PN Chemistry ; thema EDItEUR::T Technology, Engineering, Agriculture, Industrial processes::TG Mechanical engineering and materials::TGM Materials science
    Sprache: Englisch
    Format: image/jpeg
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 42
    facet.materialart.
    Unbekannt
    MDPI - Multidisciplinary Digital Publishing Institute
    Publikationsdatum: 2024-04-05
    Beschreibung: Nanofibers, particularly those of a carbonaceous content, have received increased interest in the past two decades due to their outstanding physico-chemical characteristics and their possibility to form and contribute towards a plethora of potentially advantageous materials for consumer, industrial and medical applications. Despite this, and together with the numerous research studies and published articles that have sought to investigate these aspects, the potential impact of CNTs is still not understood. Whether or not nanofibers may be able to provide a sophisticated alternative to conventional materials is still debatable, whilst their effects upon both environmental and human health are highly equivocal. How nanofibers are conceived can determine how they may interact with different environments, such as the human body. Understanding each key step of the synthesis and production of nanofibers to their use within potential applications is therefore essential in gaining an insight into how they may be perceived by any biological system and environment. Thus, obtaining such information will enable all scientific communities to begin to realize the potential advantages posed by nanofibers. The aim of this Special Issue therefore, was to provide a collective overview of nanofibers; ‘from synthesis to application’. The Issue particularly focuses upon carbon-based nanofibers, but also highlights alternative nanofiber types. Emphasis is given holistically, with articles discussing the production routes of nanofibers, their plight during their life-cycle (origin to applied form and effects over time), as well as how nanofibers could either incite conflict, or provide aid to human and environmental health.
    Schlagwort(e): QD1-999 ; Toxicology ; Chemistry ; Biology ; Material Science ; Nanofibers ; Nanotechnology ; thema EDItEUR::P Mathematics and Science::PN Chemistry
    Sprache: Englisch
    Format: application/octet-stream
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 43
    Publikationsdatum: 2024-04-04
    Beschreibung: This volume, occasioned by the centenary of the Fritz Haber Institute, formerly the Institute for Physical Chemistry and Electrochemistry, covers the institute's scientific and institutional history from its founding until the present. The institute was among the earliest established by the Kaiser Wilhelm Society, and its inauguration was one of the first steps in the development of Berlin-Dahlem into a center for scientific research. Its establishment was made possible by an endowment from Leopold Koppel, granted on the condition that Fritz Haber, well-known for his discovery of a method to synthesize ammonia from its elements, be made its director. The history of the institute has largely paralleled that of 20th-century Germany. It undertook controversial weapons research during World War I, followed by a "Golden Era" during the 1920s, in spite of financial hardships.
    Schlagwort(e): Chemistry ; Chemistry ; Fritz Haber Institute ; thema EDItEUR::P Mathematics and Science::PD Science: general issues::PDX History of science
    Sprache: Englisch
    Format: image/jpeg
    Format: image/jpeg
    Format: image/jpeg
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 44
    facet.materialart.
    Unbekannt
    transcript Verlag | transcript Verlag
    Publikationsdatum: 2024-04-04
    Beschreibung: Die Chemie büßt zugunsten physikalischer und lebenswissenschaftlicher Konzeptionen zunehmend an Deutungsmacht über die molekulare Welt ein. Sandra Lang untersucht, inwiefern die Ausdifferenzierung der chemischen Wissenschaften mit sich ebenfalls ausdifferenzierenden Zugriffen auf das Molekulare zusammenhängt. Anhand der vier exemplarischen Grenzfelder Materialwissenschaften, Biomedizin, Pharmazie und Quantenchemie und deren Narrative zur molekularen Eigenschaft der Chiralität veranschaulicht sie die transformative Phase der Chemie angesichts sich wandelnder Innovationsdispositive.
    Schlagwort(e): Chemie ; Chiralität ; Molekülkonzept ; Naturwissenschaften ; Grenzarbeit ; Interdisziplinarität ; Hybridität ; Wissenschaft ; Technik ; Wissenschaftssoziologie ; Techniksoziologie ; Wissenssoziologie ; Wissenschaftsgeschichte ; Soziologie ; Chemistry ; Chirality ; Molecule Concept ; Natural Sciences ; Border Work ; Interdisciplinarity ; Hybridity ; Science ; Technology ; Sociology of Science ; Sociology of Technology ; Sociology of Knowledge ; History of Science ; Sociology ; thema EDItEUR::P Mathematics and Science::PD Science: general issues::PDR Impact of science and technology on society ; thema EDItEUR::J Society and Social Sciences::JH Sociology and anthropology::JHB Sociology
    Sprache: Deutsch
    Format: image/jpeg
    Format: image/jpeg
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 45
    facet.materialart.
    Unbekannt
    De Gruyter | De Gruyter
    Publikationsdatum: 2024-04-11
    Beschreibung: Presents technologies and key concepts to produce suitable smart materials and intelligent structures for sensing, information and communication technology, biomedical applications (drug delivery, hyperthermia therapy), self-healing, flexible memories and construction technologies. Novel developments of environmental friendly, cost-effective and scalable production processes are discussed by experts in the field.
    Schlagwort(e): Science ; Chemistry ; Industrial & Technical ; Technology & Engineering ; Textiles & Polymers ; thema EDItEUR::T Technology, Engineering, Agriculture, Industrial processes::TD Industrial chemistry and manufacturing technologies::TDC Industrial chemistry and chemical engineering ; thema EDItEUR::T Technology, Engineering, Agriculture, Industrial processes::TG Mechanical engineering and materials::TGM Materials science
    Sprache: Englisch
    Format: image/jpeg
    Format: image/jpeg
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 46
    facet.materialart.
    Unbekannt
    De Gruyter | De Gruyter
    Publikationsdatum: 2024-04-05
    Beschreibung: Comprise definition of 1500 terms. Innovation from A to Z presents a glossary, including: Terms, older terms whose meanings have changed, acronyms, synonyms, famous names, selected abbreviations, and cross-references. A highly interdisciplinary approach incorporating strategy and entrepreneurship with technology and engineering sciences, economics, marketing, organizational behavior and theory. Ideal for engineers, managers, sales people and economists. Innovation Technology from A to Z Glossary of terms, including acronyms, synonyms, abbreviations, cross-references 1500 terms supplemented by figures and tables that clearly demonstrate the state-of-the-art in Innovation Technology
    Schlagwort(e): Science ; Chemistry ; Technology & Engineering ; Agriculture ; thema EDItEUR::P Mathematics and Science::PN Chemistry ; thema EDItEUR::T Technology, Engineering, Agriculture, Industrial processes::TV Agriculture and farming
    Sprache: Englisch
    Format: image/jpeg
    Format: image/jpeg
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 47
    facet.materialart.
    Unbekannt
    Coimbra University Press
    Publikationsdatum: 2022-01-31
    Beschreibung: This work brings together various contributions from experts in very diverse areas of knowledge, to discuss the theme ‘Light’ from various points of view. The subjects gathered in this work come from the areas of Physics, Philosophy, Transcendence, Chemistry, Optics, Literature, History of Sciences, History, Geography, International Relations, Biology, Psychology, Art, Cinema and Photography, Medicine and Museology. The texts partially reflect the contents presented at the interdisciplinary colloquium ‘Visões da Luz’ held in October 2015, on the occasion of the International Year of Light 2015, under the aegis of III-UC and open to academia and society, to teachers of the Basic and Secondary Education.
    Schlagwort(e): Geography ; Chemistry ; Literature ; Geology ; Light ; Optics ; Biology ; History ; Physics
    Sprache: Portugiesisch
    Format: image/jpeg
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 48
    facet.materialart.
    Unbekannt
    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1994-04-01
    Beschreibung: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Flam, F -- New York, N.Y. -- Science. 1994 Apr 1;264(5155):32-3.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/8140417" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): AIDS Vaccines/*chemical synthesis/immunology ; Animals ; Antibodies, Viral/biosynthesis ; Cellobiose ; Chemistry ; HIV Antibodies/biosynthesis ; Herpesvirus 4, Human/*immunology ; Societies, Scientific ; *Vaccines, Synthetic/immunology ; Viral Proteins ; Viral Vaccines/*chemical synthesis/immunology
    Print ISSN: 0036-8075
    Digitale ISSN: 1095-9203
    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 49
    facet.materialart.
    Unbekannt
    In:  Other Sources
    Publikationsdatum: 2011-08-24
    Beschreibung: The 3.0-micrometers water of hydration absorption feature observed in the IR photometry of many low-albedo and some medium-albedo asteroids strongly correlates with the 0.7-micrometers Fe(+2) to Fe(+3) oxidized iron absorption feature observed in narrowband spectrophotometry of these asteroids. Using this relationship, an empirical algorithm for predicting the presence of water of hydration in the surface material of a Solar System body using photometry obtained through the Eight-Color Asteroid Survey nu (0.550 micrometers), w (0.701 micrometers), and x (0.853 micrometers) filters was developed and applied to the ECAS photometry of asteroids and outer planet satellites. The percentage of objects in low-albedo, outer main-belt asteroid classes that test positively for water of hydration increases from P to B to C to G class and correlates linearly with the increasing mean albedos of those objects testing positively. The medium-albedo M-class asteroids do not test positively in large number using this algorithm. Aqueously altered asteroids dominate the Solar System population between heliocentric distances of 2.6 to 3.5 AU, bracketing the Solar System region where the aqueous alteration mechanism operated most strongly. One jovian satellite, J VI Himalia, and one saturnian satellite. Phoebe, tested positively for water of hydration, supporting the hypothesis that these may be captured C-class asteroids from a postaccretional dispersion. The proposed testing technique could be applied to an Earth-based survey of asteroids or a space-probe study of an asteroid's surface characteristic in order to identify a potential water source.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Icarus (ISSN 0019-1035); 111; 2; p. 456-467
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 50
    Publikationsdatum: 2011-08-24
    Beschreibung: The infrared transmission spectra and photochemical behavior of various organic compounds isolated in solid N2 ices, appropriate for applications to Triton ad Pluto, are presented. It is shown that excess absorption in the surface spectra of Triton and Pluto, i.e., absorption not explained by present models incorporating molecules already identified on these bodies (N2, CH4, CO, and CO2), that starts near 4450/cm (2.25 microns) and extends to lower frequencies, may be due to alkanes (C(n)H(2n+2)) and related molecules frozen in the nitrogen. Branched and linear alkanes may be responsible. Experiments in which the photochemstry of N2: CH4 and N2: CH4: CO ices was explored demonsrtrate that the surface ices of Triton and Pluto may contain a wide variety of additional species containing H, C, O, and N. Of these, the reactive molecule diazomethane, CH2N2, is particularly important since it may be largely responsible for the synthesis of larger alkanes from CH4 and other small alkanes. Diazomethane would also be expected to drive chemical reactions involving organics in the surface ices of Triton and Pluto toward saturation, i.e., to reduce multiple CC bonds. The positions and intrinsic strengths (A values) of many of the infrared absorption bands of N2 matrix-isolated molecules of relevance to Triton and Pluto have also been determined. These can be used to aid in their search and to place constraints on their abundances.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Icarus (ISSN 0019-1035); 111; 1; p. 151-173
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 51
    Publikationsdatum: 2011-08-24
    Beschreibung: The compressible dynamic stall flowfield over a NACA 0012 airfoil transiently pitching from 0 to 60 deg at a constant rate under compressible flow conditions has been studied using real-time interferometry. A quantitative description of the overall flowfield, including the finer details of dynamic stall vortex formation, growth, and the concomitant changes in the airfoil pressure distribution, has been provided by analyzing the interferograms. For Mach numbers above 0.4, small multiple shocks appear near the leading edge and are present through the initial stages of dynamic stall. Dynamic stall was found to occur coincidentally with the bursting of the separation bubble over the airfoil. Compressibility was found to confine the dynamic stall vortical structure closer to the airfoil surface. The measurements show that the peak suction pressure coefficient drops with increasing freestream Mach number, and also it lags the steady flow values at any given angle of attack. As the dynamic stall vortex is shed, an anti-clockwise vortex is induced near the trailing edge, which actively interacts with the post-stall flow.
    Schlagwort(e): AERODYNAMICS
    Materialart: AIAA Journal (ISSN 0001-1452); 32; 3; p. 586-593
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 52
    facet.materialart.
    Unbekannt
    In:  Other Sources
    Publikationsdatum: 2011-08-24
    Beschreibung: The effect of the porous leading edge of an airfoil on the blade-vortex interaction noise, which dominates the far-field acoustic spectrum of the helicopter, is investigated. The thin-layer Navier-Stokes equations are solved with a high-order upwind-biased scheme and a multizonal grid system. The Baldwin-Lomax turbulence model is modified for considering transpiration on the surface. The amplitudes of the propagating acoustic wave in the near field are calculated directly from the computation. The porosity effect on the surface is modeled in two ways: (1) imposition of prescribed transpiration velocity distribution and (2) calculation of transpiration velocity distribution by Darcy's law. Results show leading-edge transpiration can suppress pressure fluctuations at the leading edge during blade-vortex interaction and consequently reduce the amplitude of propagating noise by 30% at a maximum in the near field.
    Schlagwort(e): AERODYNAMICS
    Materialart: AIAA Journal (ISSN 0001-1452); 32; 3; p. 480-488
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 53
    Publikationsdatum: 2011-08-24
    Beschreibung: A method has been developed for calculating the viscous flow about airfoils with and without deflected flaps at -90 deg incidence. This method provides for the solution of the unsteady incompressible Navier-Stokes equations by means of an implicit technique. The solution is calculated on a body-fitted computational mesh using a staggered-grid method. The vorticity is defined at the node points, and the velocity components are defined at the mesh-cell sides. The staggered-grid orientation provides for accurate representation of vorticity at the node points and the continuity equation at the mesh-cell centers. The method provides for the noniterative solution of the flowfield and satisfies the continuity equation to machine zero at each time step. The method is evaluated in terms of its stability to predict two-dimensional flow about an airfoil at -90-deg incidence for varying Reynolds number and laminar/turbulent models. The variations of the average loading and surface pressure distribution due to flap deflection, Reynolds number, and laminar or turbulent flow are presented and compared with experimental results. The comparisom indicate that the calculated drag and drag reduction caused by flap deflection and the calculated average surface pressure are in excellent agreement with the measured results at a similar Reynolds number.
    Schlagwort(e): AERODYNAMICS
    Materialart: AIAA Journal (ISSN 0001-1452); 32; 3; p. 449-454
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 54
    facet.materialart.
    Unbekannt
    In:  Other Sources
    Publikationsdatum: 2011-08-24
    Beschreibung: This report presents the most recent spherical harmonic topography model of Venus developed at Jet Propulsion Laboratory. It was produced by a spherical harmonic analysis of the most complete set of Magellan altimetry data, augmented by Pioneer Venus and Venera data. The harmonic coefficients of the topography were computed to degree and order 360. Compared to previous topography models, this one has the highest correlation with the gravity field of Venus.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Icarus (ISSN 0019-1035); 112; 1; p. 27-33
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 55
    facet.materialart.
    Unbekannt
    In:  Other Sources
    Publikationsdatum: 2011-08-24
    Beschreibung: The 500-Myr average crater retention age for Venus has raised questions about the present-day level of tectonic activity. In this study we examine the relationship between the gravity and topography of four large volcanic swells, Beta, Atla, Bell, and Western Eistla Regiones, for clues about their stage evolution. The Magellan line-of-sight gravity data are inverted using a point mass model of the anomalous mass to solve for the local vertical gravity field. Spectral admittance calculated from both the local gravity inversions and a spherical harmonic model is compared to three models of compensation: local compensation, a 'flexural' model with local and regional compensation of surface and subsurface loads, and a 'hotspot' model of compensation that includes top loading by volcanoes and subsurface loading due to a deep, low density mass anomaly. The coherence is also calculated in each region, but yields an elastic thickness estimate only at Bell Regio. In all models, the long wavelengths are compensated locally. Our results may indicate a relatively old, possibly inactive plume.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Icarus (ISSN 0019-1035); 112; 1; p. 2-26
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 56
    Publikationsdatum: 2011-08-24
    Beschreibung: Rotor noise prediction codes predict the thickness and loading noise produced by a helicopter rotor, given the blade motion, rotor operating conditions, and fluctuating force distribution over the blade surface. However, the criticality of these various inputs, and their respective effects on the predicted acoustic field, have never been fully addressed. This paper examines the importance of these inputs, and the sensitivity of the acoustic predicitions to a variation of each parameter. The effects of collective and cyclic pitch, as well as coning and cyclic flapping, are presented. Blade loading inputs are examined to determine the necessary spatial and temporal resolution, as well as the importance of the chordwise distribution. The acoustic predictions show regions in the acoustic field where significant errors occur when simplified blade motions or blade loadings are used. An assessment of the variation in the predicted acoustic field is balanced by a consideration of Central Processing Unit (CPU) time necessary for the various approximations.
    Schlagwort(e): AERODYNAMICS
    Materialart: American Helicopter Society, Journal (ISSN 0002-8711); 39; 3; p. 43-52
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 57
    facet.materialart.
    Unbekannt
    In:  Other Sources
    Publikationsdatum: 2011-08-24
    Beschreibung: Recent mapping studies west of Elysium Mons, Mars, have pinpointed subice features that suggest the existence of a frozen paleolake in Utopia Planitia as recently as 1.8 billion years ago. The subice features are interpreted to be hyaloclastic ridges and hills, table moutains, associated joekulhalaup deposits, and fluvial channels. Photoclinometric studies of these features and of a basal scarp around the northwest flank of Elysium Mons interpreted to have been an ice-sheet boundary indicate that the maximum thickness of ice within the basin may have been about 180 m. This thickness of ice during a relatively late stage of Martian geologic history would have important implications concerning the atmospheric, the climatic, and possibly the exobiologic history of the planet.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Icarus (ISSN 0019-1035); 109; 2; p. 393-406
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 58
    facet.materialart.
    Unbekannt
    In:  Other Sources
    Publikationsdatum: 2011-08-24
    Beschreibung: The ion and electron momentum equations, along with Ampere's law, are solved for the ion and electron drift velocities and the electric field in the subsolar Venus ionosphere, assuming a partially ionized gas and a single ion species having the ion mean mass. All collision terms among the ions, electrons and neutral particles are retained in the equations. A general expression for the evolution of the magnetic field is derived and compared with earlier expressions. Subsolar region data in the altitude range 150-300 km from the Pioneer Venus Orbiter are used to calculate altitude profiles of the components of the current due to the electric field, gradients of pressure, and gravity. Altitude profiles of the ion and electron velocities as well as the electric field, electrodynamic heating, and the energy density are determined. Only orbits having a complete set of measured plasma temperatures and densities, neutral densities, and magnetic field were considered for analysis; the results are shown only for orbit 202. The vertical velocity at altitudes above 220 km is upgoing for orbit 202. This result is consistent with observations of molecular ions at high altitudes and of plasma flow to the nightside, both of which require upward velocity of ions from the dayside ionosphere. Above about 230 km the momentum equations are extremely sensitive to the altitude profiles of density, temperature, and magnetic field.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Journal of Geophysical Research (ISSN 0148-0227); p. 8791-8800
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 59
    Publikationsdatum: 2011-08-24
    Beschreibung: We report here analyses of olivines and pyroxenes, and petrofabrics of 27 chondritic interplanetary dust particles (IDPs), comparing those from anhydrous and hydrous types. Approximately 40% of the hydrous particles contain diopside, a probable indicator of parent body thermal metamorphism, while this mineral is rarely present in the anhydrous particles. Based on this evidence, we find that hydrous and anhydrous IDPs are, in general, not directly related, and we conclude that olivine and pyroxene major-element compositions can be used to help discriminate between IDPs that are (1) predominantly nebular condensates, and lately resided in anhydrous or icy (no liquids) primitive parent bodies, and (2) those originating from more geochemically active parent bodies (probably hydrous and anhydrous asteroids).
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Meteoritics (ISSN 0026-1114); 29; 5; p. 616-620
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 60
    Publikationsdatum: 2011-08-24
    Beschreibung: This paper reports on a magnetic field phenomenon, hereafter referred to as null fields, which were discovered during the inbound pass of the recent flyby of Jupiter by the Ulysses spacecraft. These null fields which were observed in the outer dayside magnetosphere are characterised by brief but sharp decreases of the field magnitude to values less than 1 nT. The nulls are distinguished from the current sheet signatures characteristic of the middle magnetosphere by the fact that the field does not reverse across the event. A field configuration is suggested that accounts for the observed features of the events.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Geophysical Research Letters (ISSN 0094-8276); 21; 6; p. 405-408
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 61
    facet.materialart.
    Unbekannt
    In:  Other Sources
    Publikationsdatum: 2011-08-24
    Beschreibung: The U.S. National Aeronautics and Space Administration (NASA) Balloon Program has been highly successful since recovering from the catastrophic balloon failure problems of the early to mid 1980s. Balloons have continued to perform at unprecedented success rates. The comprehensive research and development (R&D) effort has continued with advances being made across the spectrum of balloon related disciplines. The long duration balloon project will be transitioning from a development effort to an operational capability this year. Recently, emphasis has been placed on the development and implementation of new support systems and facilities. A new permanent launch facility at Fort Sumner, New Mexico has been established. New ground station support equipment is being implemented, and a new heavy load launch vehicle is scheduled to be implemented in 1992. The progress, status and future plans for these and other aspects of the NASA program will be presented.
    Schlagwort(e): AERODYNAMICS
    Materialart: Advances in Space Research (ISSN 0273-1177); 14; 2; p. (2)129-(2)135
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 62
    facet.materialart.
    Unbekannt
    In:  Other Sources
    Publikationsdatum: 2011-08-24
    Beschreibung: The catastrophic balloon failure during the first half of the 1980's identified the need for a comprehensive and continuing balloon research and development (R&D) commitment by NASA. Technical understanding was lacking in many of the disciplines and processes associated with scientific ballooning. A comprehensive balloon R&D plan was developed in 1986 and implemented in 1987. The objectives were to develop the understanding of balloon system performance, limitations, and failure mechanisms. The program consisted of five major technical areas: structures, performance and analysis, materials, chemistry and processing, and quality control. Research activitites have been conducted at NASA/Goddard Space Flight Center (GSFC)-Wallops Flight Facility (WFF), other NASA centers and government facilities, universities, and the balloon manufacturers. Several new and increased capabilities and resources have resulted from this activity. The findings, capabilities, and plan of the balloon R&D program are presented.
    Schlagwort(e): AERODYNAMICS
    Materialart: Advances in Space Research (ISSN 0273-1177); 14; 2; p. (2)137-(2)146
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 63
    Publikationsdatum: 2011-08-24
    Beschreibung: Caps have been used to structurally reinforce scientific research balloons since the late 1950's. The scientific research balloons used by the National Aeronautics and Space Administration (NASA) use internal caps. A NASA cap placement specification does not exist since no empirical information exisits concerning cap placement. To develop a cap placement specification, NASA has completed two in-hangar inflation tests comparing the structural contributions of internal caps and external caps. The tests used small scale test balloons designed to develop the highest possible stresses within the constraints of the hangar and balloon materials. An externally capped test balloon and an internally capped test balloon were designed, built, inflated and simulated to determine the structural contributions and benefits of each. The results of the tests and simulations are presented.
    Schlagwort(e): AERODYNAMICS
    Materialart: Advances in Space Research (ISSN 0273-1177); 14; 2; p. (2)49-(2)52
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 64
    Publikationsdatum: 2011-08-24
    Beschreibung: Geochemical profiles of surface units, impact, and volcanic features are studied in detail to determine the underlying structure in an area of extensive mare/highland interface, Sinus Amoris. This study region includes and surrounds the northeastern embayment of Mare Tranquillitatis. The concentrations of two major rock-forming elements (Mg and Al), which were derived from the Apollo 15 orbital geochemical measurements, were used in this study. Mapped units and deposits associated with craters in the northwestern part of the region tend to have correlated low Mg and Al concentrations, indicating the presence of Potassium (K)-Rare Earth Elements (REE)-Phosphorus (P) (KREEP)-enriched basalt. Found along the northeastern rim of Tranquillitatis were areas with correlated high Mg and Al concentration, indicating the presence of troctolite. Distinctive west/east and north/south trends were observed in the concentrations of Mg and Al, and, by implication, in the distribution of major rock components on the surface. Evidence for a systematic geochemical transition in highland or basin-forming units may be observed here in the form of distinctive differences in chemistry in otherwise similar units in the western and eastern portions of the study region.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Earth, Moon, and Planets (ISSN 0167-9295); 64; 2; p. 165-185
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 65
    Publikationsdatum: 2011-08-24
    Beschreibung: The purpose of this Note is to present results from an analytic/experimental study that investigated the potential for passively changing blade twist through the use of extension-twist coupling. A set of composite model rotor blades was manufactured from existing blade molds for a low-twist metal helicopter rotor blade, with a view toward establishing a preliminary proof concept for extension-twist-coupled rotor blades. Data were obtained in hover for both a ballasted and unballasted blade configuration in sea-level atmospheric conditions. Test data were compared with results obtained from a geometrically nonlinear analysis of a detailed finite element model of the rotor blade developed in MSC/NASTRAN.
    Schlagwort(e): AERODYNAMICS
    Materialart: AIAA Journal (ISSN 0001-1452); 32; 7; p. 1549-1551
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 66
    Publikationsdatum: 2011-08-24
    Beschreibung: The paper considers the compressible Rayleigh equation as a model for the Mach wave emission mechanism associated with high-temperature supersonic jets. Solutions to the compressible Rayleigh equation reveal the existence of several families of supersonically convecting instability waves. These waves directly radiate noise to the jet far field. The predicted noise characteristics are compared to previously acquired experimental data for an axisymmetric Mach 2 fully pressure balanced jet operating over a range of jet total temperatures from ambient to 1370 K. The results of this comparison show that the first-order supersonic instability wave and the Kelvin-Hemlhlotz first-, second-, and third-order modes have directional radiation characteristics that are in agreement with observed data. The assumption of equal initial amplitudes for all of the waves leads to the conclusion that the flapping mode of instability dominates the noise radiatio process of supersonic jets. At a jet temperature of 1370 K, supersonic instability waves are predicted to dominate the noise radiated at high frequency at narrow angles to the jet axis.
    Schlagwort(e): AERODYNAMICS
    Materialart: AIAA Journal (ISSN 0001-1452); 32; 12; p. 2345-2350
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 67
    Publikationsdatum: 2011-08-24
    Beschreibung: The objective of the present work is to study the mixing characteristics of a linear array of supersonic rectangular jets under conditions of screech synchronization. The screech synchronization at a fully expanded jet Mach number of 1.61 is achieved by a precise adjustment of the internozzle spacing. To our knowledge, such an experiment on the resonant mixing of screech synchronized multiple rectangular jets has not been reported before. The results are compared with the case where the screech was suppressed in the multijet configuration.
    Schlagwort(e): AERODYNAMICS
    Materialart: AIAA Journal (ISSN 0001-1452); 32; 12; p. 2477-2480
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 68
    facet.materialart.
    Unbekannt
    In:  Other Sources
    Publikationsdatum: 2011-08-24
    Beschreibung: The objective of the present investigation is to assess the effect of the spatial order of accuracy used for the evaluation of the inviscid fluxes on the resolution of higher order quantitites, such as velocity gradients. The viscous terms are computed as second-order accurate with central difference formulas, even though for the explicit part of the algorithm higher order approximations may be used. A viscous/inviscid method is used, and the outer part of the flowfield is computed with the inviscid flow equations. The viscous boundary-layer type flow region close to the body surface is computed with an algebraic eddy viscosity model. Results obtained with the conservative and nonconservative formulations and the viscous/inviscid approach are compared with available experimental data. The effect of grid refinement on the accuracy of the solution is also presented.
    Schlagwort(e): AERODYNAMICS
    Materialart: AIAA Journal (ISSN 0001-1452); 32; 12; p. 2471-2474
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 69
    facet.materialart.
    Unbekannt
    In:  Other Sources
    Publikationsdatum: 2011-08-24
    Beschreibung: The aerobraking orbital activities of Magelland during the gravity mapping of Venus are discussed. The goal of aerobraking was to circularize Magellan's orbit. By aerobraking the spacecraft into a nearly circula orbit, the Magellan team was able to provide scientists with a different data set to deepen their understanding of what is going on beneath Venus' surface. Before undertaking its gravity-mapping mission, Magellan completed three cycles of radar mapping. This repeated coverage allowed the spacecraft to see some of Venus' geologic features from different viewing angles. Various aspects of the mission are discussed, and maps of Venus are presented.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Planetary Report (ISSN 0736-3680); 14; 2; p. 6-13
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 70
    Publikationsdatum: 2011-08-24
    Beschreibung: Spatial correlation among densely packed particles can substantially change their single-scattering properties, thus making questionable the applicability of the independent scattering approximation in calculations of light scattering by planetary regoliths. The same problem arises in geophysics in light scattering computations for snow, frosts, and bare soil. In this paper, we use a dense-medium light-scattering theory based on the introduction of the static structure factor to calculate asymmetry parameters of the phase function for densely packed particles with real refractive indices 1.31 and 1.66, approximating water ice and soil particles, respectively, and imaginary refractive indices 0, 0.01, and 0.3. For sparsely distributed, independently scattering grains, the calculated asymmetry parameters are always positive and always larger than those for densely packed particles. For densely packed grains, the asymmetry parameters may be negative but only for radius-to-wavelength ratios from about 0.1 to about 0.4. With decreasing particle size, the calculated asymmetry parameters tend to zero independently of the compaction state. In the geometrical optics regime, the asymmetry parameters for densely packed scatterers are positive and very close to those for independently scattering grains. These results may have important implications for remote sensing of the Earth and solid planetary surfaces. In particular, it is demonstrated that negative asymmetry parameters derived with some approximate multiple-scattering theories may be physically irrelevant and can be the result of using an inaccurate bidirectional reflection function combined with the ill-conditionally of the inverse scattering problem.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Journal of Quantitative Spectroscopy & Radiative Transfer (ISSN 0022-4073); 52; 1; p. 95-110
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 71
    facet.materialart.
    Unbekannt
    In:  Other Sources
    Publikationsdatum: 2011-08-24
    Beschreibung: The first comprehensive discussion of the south seasonal polar cap spectra obtained by the Mariner 7 infrared spectrometer in the short-wavelength region (2-4 microns) is presented. The infrared spectra is correlated with images acquired by the wide-angle camera. Significant spectral variation is noted in the cap interior and regions of varying water frost abundance, CO2 ice/frost cover, and CO2-ice path length can be distinguished. Many of these spectral variations correlate with heterogeneity noted in the camera images, but certain significant infrared spectral variations are not discernible in the visible. Simple reflectance models are used to classify the observed spectral variations into four regions. Region I is at the cap edge, where there is enhanced absorption beyond 3 microns inferred to be caused by an increased abundance of water frost. The increase in water abundance over that in the interior is on the level of a few parts per thousand or less. Region II is the typical cap interior characterized by spectral features of CO2 ice at grain sizes of several millimeters to centimeters. These spectra also indicate the presence of water frost at the parts per thousand level. A third, unusual region (III), is defined by three spectra in which weak CO2 absorption features are as much as twice as strong as in the average cap spectra and are assumed to be caused by an increased path length in the CO2. Such large paths are inconsistent with the high reflectance in the visible and at 2.2 microns and suggest layered structures or deposition conditions that are not accounted for in current reflectance models. The final region (IV) is an area of thinning frost coverage or transparent ice well in the interior of the seasonal cap. These spectra are a combination of CO2 and ground signatures.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Journal of Geophysical Research (ISSN 0148-0227); 99; E10; p. 21,143-21,152
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 72
    facet.materialart.
    Unbekannt
    In:  Other Sources
    Publikationsdatum: 2011-08-24
    Beschreibung: We report new measurements of the sodium emission intensity seen in a line of sight just above the surface of the Moon. These data show a strong dependence on lunar phase. The emission intensity decreases from a maximum around first quarter (phase angle 90 deg) to very small values near full Moon (phase angle 0 deg). This suggests that the rate of sodium vapor production from the lunar surface is largest at the subsolar point and becomes small near the terminator. However, the sodium emission near full Moon falls below that which would be expected for solar photon-driven processes. Since the solar wind flux decreases substantially when the Moon enters the Earth's magnetotail near full Moon, while the global solar photon flux is undiminished, we suggest that solar wind sputtering is the dominant process for sodium production.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Geophysical Research Letters (ISSN 0094-8276); 21; 21; p. 2263-2266
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 73
    Publikationsdatum: 2011-08-24
    Beschreibung: Infrared diffuse reflectance spectra (2.53-25 microns) of some carbonaceous (C) chondrites were measured. The integrated intensity of the absorption bands near 3 microns caused by hydrous minerals were compared with the modal content of hydrous minerals for the meteorites. The CM and CI chondrites show larger values of the intergated intensity than those of the unique C chondrites Y82162, Y86720 and B7904, suggesting that the amount of hydrous minerals in the CM and CI chondrites is larger, which supports the contention that hydrous minerals were dehydrated by thermal metamorphism in the unique chondrites. Orgueil (CI) has the largest value of the integrated intensity among the C chondrites we measured and shows a sharp absorption band at 3685/cm (2.71 microns) that is not seen in the spectra of the CM chondrites. There is an excellent correlation between the observed hydrogen content in C chondrites and the integrated intensity. The CM chondrites show a wide variation in the strength of absorption bands at 1470/cm (6.8 microns), despite the similarity in absorption features near 3 micron for all CM chondites. The 1470/cm band could be due to the presence of some hydrocarbons but may also be a result of terrestrial alteration processes.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Meteoritics (ISSN 0026-1114); 29; 6; p. 849-853
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 74
    Publikationsdatum: 2011-08-24
    Beschreibung: Oxygen production from a lunar rock has been experimentally demonstrated for the first time. A 10 g sample of high-Ti basalt 70035 was reduced with hydrogen in seven experiments at temperatures of 900-1050 C and pressures of 14.7-150 psia. In all experiments, water evolution began almost immediately and was essentially complete in tens of minutes. Oxygen yields ranged from 2.93 to 4.61% of the starting sample weight, and showed weak dependence on temperature and pressure. Analysis of the solid samples demonstrated total reduction of Fe(2+) in ilmenite and small degrees of reduction in olivine and pyroxene. Ti O2 was also partially reduced to one or more suboxides. Data from these experiments provide a basis for predicting the yield of oxygen from lunar basalt as well as new constraints on natural reduction in the lunar regolith.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Journal of Geophysical Research (ISSN 0148-0227); 99; E5; p. 10,887-10,897
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 75
    Publikationsdatum: 2011-08-24
    Beschreibung: ARC2D is a computational fluid dynamics program developed at the NASA Ames Research Center specifically for airfoil computations. The program uses implicit finite-difference techniques to solve two-dimensional Euler equations and thin layer Navier-Stokes equations. It is based on the Beam and Warming implicit approximate factorization algorithm in generalized coordinates. The methods are either time accurate or accelerated non-time accurate steady state schemes. The evolution of the solution through time is physically realistic; good solution accuracy is dependent on mesh spacing and boundary conditions. The mathematical development of ARC2D begins with the strong conservation law form of the two-dimensional Navier-Stokes equations in Cartesian coordinates, which admits shock capturing. The Navier-Stokes equations can be transformed from Cartesian coordinates to generalized curvilinear coordinates in a manner that permits one computational code to serve a wide variety of physical geometries and grid systems. ARC2D includes an algebraic mixing length model to approximate the effect of turbulence. In cases of high Reynolds number viscous flows, thin layer approximation can be applied. ARC2D allows for a variety of solutions to stability boundaries, such as those encountered in flows with shocks. The user has considerable flexibility in assigning geometry and developing grid patterns, as well as in assigning boundary conditions. However, the ARC2D model is most appropriate for attached and mildly separated boundary layers; no attempt is made to model wake regions and widely separated flows. The techniques have been successfully used for a variety of inviscid and viscous flowfield calculations. The Cray version of ARC2D is written in FORTRAN 77 for use on Cray series computers and requires approximately 5Mb memory. The program is fully vectorized. The tape includes variations for the COS and UNICOS operating systems. Also included is a sample routine for CONVEX computers to emulate Cray system time calls, which should be easy to modify for other machines as well. The standard distribution media for this version is a 9-track 1600 BPI ASCII Card Image format magnetic tape. The Cray version was developed in 1987. The IBM ES/3090 version is an IBM port of the Cray version. It is written in IBM VS FORTRAN and has the capability of executing in both vector and parallel modes on the MVS/XA operating system and in vector mode on the VM/XA operating system. Various options of the IBM VS FORTRAN compiler provide new features for the ES/3090 version, including 64-bit arithmetic and up to 2 GB of virtual addressability. The IBM ES/3090 version is available only as a 9-track, 1600 BPI IBM IEBCOPY format magnetic tape. The IBM ES/3090 version was developed in 1989. The DEC RISC ULTRIX version is a DEC port of the Cray version. It is written in FORTRAN 77 for RISC-based Digital Equipment platforms. The memory requirement is approximately 7Mb of main memory. It is available in UNIX tar format on TK50 tape cartridge. The port to DEC RISC ULTRIX was done in 1990. COS and UNICOS are trademarks and Cray is a registered trademark of Cray Research, Inc. IBM, ES/3090, VS FORTRAN, MVS/XA, and VM/XA are registered trademarks of International Business Machines. DEC and ULTRIX are registered trademarks of Digital Equipment Corporation.
    Schlagwort(e): AERODYNAMICS
    Materialart: COS-10029
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 76
    facet.materialart.
    Unbekannt
    In:  Other Sources
    Publikationsdatum: 2011-08-24
    Beschreibung: Panel method computer programs are software tools of moderate cost used for solving a wide range of engineering problems. The panel code PMARC_12 (Panel Method Ames Research Center, version 12) can compute the potential flow field around complex three-dimensional bodies such as complete aircraft models. PMARC_12 is a well-documented, highly structured code with an open architecture that facilitates modifications and the addition of new features. Adjustable arrays are used throughout the code, with dimensioning controlled by a set of parameter statements contained in an include file; thus, the size of the code (i.e. the number of panels that it can handle) can be changed very quickly. This allows the user to tailor PMARC_12 to specific problems and computer hardware constraints. In addition, PMARC_12 can be configured (through one of the parameter statements in the include file) so that the code's iterative matrix solver is run entirely in RAM, rather than reading a large matrix from disk at each iteration. This significantly increases the execution speed of the code, but it requires a large amount of RAM memory. PMARC_12 contains several advanced features, including internal flow modeling, a time-stepping wake model for simulating either steady or unsteady (including oscillatory) motions, a Trefftz plane induced drag computation, off-body and on-body streamline computations, and computation of boundary layer parameters using a two-dimensional integral boundary layer method along surface streamlines. In a panel method, the surface of the body over which the flow field is to be computed is represented by a set of panels. Singularities are distributed on the panels to perturb the flow field around the body surfaces. PMARC_12 uses constant strength source and doublet distributions over each panel, thus making it a low order panel method. Higher order panel methods allow the singularity strength to vary linearly or quadratically across each panel. Experience has shown that low order panel methods can provide nearly the same accuracy as higher order methods over a wide range of cases with significantly reduced computation times; hence, the low order formulation was adopted for PMARC_12. The flow problem is solved by modeling the body as a closed surface dividing space into two regions: the region external to the surface in which an unknown velocity potential exists representing the flow field of interest, and the region internal to the surface in which a known velocity potential (representing a fictitious flow) is prescribed as a boundary condition. Both velocity potentials are required to satisfy Laplace's equation. A surface integral equation for the unknown potential external to the surface can be written by applying Green's Theorem to the external region. Using the internal potential and zero flow through the surface as boundary conditions, the unknown potential external to the surface can be solved for. When the internal flow option, which allows the analysis of closed ducts, wind tunnels, and similar internal flow problems, is selected, the geometry is modeled such that the flow field of interest is inside the geometry and the fictitious flow is outside the geometry. Items such as wings, struts, or aircraft models can be included in the internal flow problem. The time-stepping wake model gives PMARC_12 the ability to model both steady and unsteady flow problems. The wake is convected downstream from the wake-separation line by the local velocity field. With each time step, a new row of wake panels is added to the wake at the wake-separation line. Time stepping can start from time t=0 (no initial wake) or from time t=t0 (an initial wake is specified). A wide range of motions can be prescribed, including constant rates of translation, constant rate of rotation about an arbitrary axis, oscillatory translation, and oscillatory rotation about any of the three coordinate axes. Investigators interested in a visual representation of the phenomenon they are studying with PMARC_12 may want to consider obtaining the program GVS (ARC-13361), the General Visualization System. GVS is a Silicon Graphics IRIS program which was created for the purpose of supporting the scientific visualization needs of PMARC_12. GVS is available separately from COSMIC. PMARC_12 is written in standard FORTRAN 77, with the exception of the NAMELIST extension used for input. This makes the code fairly machine independent. A compiler which supports the NAMELIST extension is required. The amount of free disk space and RAM memory required for PMARC_12 will vary depending on how the code is dimensioned using the parameter statements in the include file. The recommended minimum requirements are 20Mb of free disk space and 4Mb of RAM. PMARC_12 has been successfully implemented on a Macintosh II running System 6.0.7 or 7.0 (using MPW/Language Systems Fortran 3.0), a Sun SLC running SunOS 4.1.1, an HP 720 running HP-UX 8.07, an SGI IRIS running IRIX 4.0 (it will not run under IRIX 3.x.x without modifications), an IBM RS/6000 running AIX, a DECstation 3100 running ULTRIX, and a CRAY-YMP running UNICOS 6.0 or later. Due to its memory requirements, this program does not readily lend itself to implementation on MS-DOS based machines. The standard distribution medium for PMARC_12 is a set of three 3.5 inch 800K Macintosh format diskettes and one 3.5 inch 1.44Mb Macintosh format diskette which contains an electronic copy of the documentation in MS Word 5.0 format for the Macintosh. Alternate distribution media and formats are available upon request, but these will not include the electronic version of the document. No executables are included on the distribution media. This program is an update to PMARC version 11, which was released in 1989. PMARC_12 was released in 1993. It is available only for use by United States citizens.
    Schlagwort(e): AERODYNAMICS
    Materialart: ARC-13362
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 77
    facet.materialart.
    Unbekannt
    In:  Other Sources
    Publikationsdatum: 2011-08-24
    Beschreibung: This program determines the supersonic flowfield surrounding three-dimensional wing-body configurations of a delta wing. It was designed to provide the numerical computation of three dimensional inviscid, flowfields of either perfect or real gases about supersonic or hypersonic airplanes. The governing equations in conservation law form are solved by a finite difference method using a second order noncentered algorithm between the body and the outermost shock wave, which is treated as a sharp discontinuity. Secondary shocks which form between these boundaries are captured automatically. The flowfield between the body and outermost shock is treated in a shock capturing fashion and therefore allows for the correct formation of secondary internal shocks . The program operates in batch mode, is in CDC update format, has been implemented on the CDC 7600, and requires more than 140K (octal) word locations.
    Schlagwort(e): AERODYNAMICS
    Materialart: ARC-11015
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 78
    facet.materialart.
    Unbekannt
    In:  Other Sources
    Publikationsdatum: 2011-08-24
    Beschreibung: The ORBSIM program was developed for the accurate extraction of geophysical model parameters from Doppler radio tracking data acquired from orbiting planetary spacecraft. The model of the proposed planetary structure is used in a numerical integration of the spacecraft along simulated trajectories around the primary body. Using line of sight (LOS) Doppler residuals, ORBSIM applies fast and efficient modelling and optimization procedures which avoid the traditional complex dynamic reduction of data. ORBSIM produces quantitative geophysical results such as size, depth, and mass. ORBSIM has been used extensively to investigate topographic features on the Moon, Mars, and Venus. The program has proven particulary suitable for modelling gravitational anomalies and mascons. The basic observable for spacecraft-based gravity data is the Doppler frequency shift of a transponded radio signal. The time derivative of this signal carries information regarding the gravity field acting on the spacecraft in the LOS direction (the LOS direction being the path between the spacecraft and the receiving station, either Earth or another satellite). There are many dynamic factors taken into account: earth rotation, solar radiation, acceleration from planetary bodies, tracking station time and location adjustments, etc. The actual trajectories of the spacecraft are simulated using least squares fitted to conic motion. The theoretical Doppler readings from the simulated orbits are compared to actual Doppler observations and another least squares adjustment is made. ORBSIM has three modes of operation: trajectory simulation, optimization, and gravity modelling. In all cases, an initial gravity model of curved and/or flat disks, harmonics, and/or a force table are required input. ORBSIM is written in FORTRAN 77 for batch execution and has been implemented on a DEC VAX 11/780 computer operating under VMS. This program was released in 1985.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: NPO-16671
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 79
    facet.materialart.
    Unbekannt
    In:  Other Sources
    Publikationsdatum: 2011-08-24
    Beschreibung: This theoretical aerodynamics program, TAD, was developed to predict the aerodynamic characteristics of vehicles with sounding rocket configurations. These slender, axisymmetric finned vehicle configurations have a wide range of aeronautical applications from rockets to high speed armament. Over a given range of Mach numbers, TAD will compute the normal force coefficient derivative, the center-of-pressure, the roll forcing moment coefficient derivative, the roll damping moment coefficient derivative, and the pitch damping moment coefficient derivative of a sounding rocket configured vehicle. The vehicle may consist of a sharp pointed nose of cone or tangent ogive shape, up to nine other body divisions of conical shoulder, conical boattail, or circular cylinder shape, and fins of trapezoid planform shape with constant cross section and either three or four fins per fin set. The characteristics computed by TAD have been shown to be accurate to within ten percent of experimental data in the supersonic region. The TAD program calculates the characteristics of separate portions of the vehicle, calculates the interference between separate portions of the vehicle, and then combines the results to form a total vehicle solution. Also, TAD can be used to calculate the characteristics of the body or fins separately as an aid in the design process. Input to the TAD program consists of simple descriptions of the body and fin geometries and the Mach range of interest. Output includes the aerodynamic characteristics of the total vehicle, or user-selected portions, at specified points over the mach range. The TAD program is written in FORTRAN IV for batch execution and has been implemented on an IBM 360 computer with a central memory requirement of approximately 123K of 8 bit bytes. The TAD program was originally developed in 1967 and last updated in 1972.
    Schlagwort(e): AERODYNAMICS
    Materialart: GSC-12680
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 80
    facet.materialart.
    Unbekannt
    In:  Other Sources
    Publikationsdatum: 2011-08-24
    Beschreibung: This program, which is called 'AOFA', determines the complete viscous and inviscid flow around a body of revolution at a given angle of attack and traveling at supersonic speeds. The viscous calculations from this program agree with experimental values for surface and pitot pressures and with surface heating rates. At high speeds, lee-side flows are important because the local heating is difficult to correlate and because the shed vortices can interact with vehicle components such as a canopy or a vertical tail. This program should find application in the design analysis of any high speed vehicle. Lee-side flows are difficult to calculate because thin-boundary-layer theory is not applicable and the concept of matching inviscid and viscous flow is questionable. This program uses the parabolic approximation to the compressible Navier-Stokes equations and solves for the complete inviscid and viscous regions of flow, including the pressure. The parabolic approximation results from the assumption that the stress derivatives in the streamwise direction are small in comparison with derivatives in the normal and circumferential directions. This assumption permits the equation to be solved by an implicit finite difference marching technique which proceeds downstream from the initial data point, provided the inviscid portion of flow is supersonic. The viscous cross-flow separation is also determined as part of the solution. To use this method it is necessary to first determine an initial data point in a region where the inviscid portion of the flow is supersonic. Input to this program consists of two parts. Problem description is conveyed to the program by namelist input. Initial data is acquired by the program as formatted data. Because of the large amount of run time this program can consume the program includes a restart capability. Output is in printed format and magnetic tape for further processing. This program is written in FORTRAN IV and has been implemented on a CDC 7600 with a central memory requirement of approximately 35K (octal) of 60 bit words.
    Schlagwort(e): AERODYNAMICS
    Materialart: ARC-11087
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 81
    facet.materialart.
    Unbekannt
    In:  Other Sources
    Publikationsdatum: 2011-08-24
    Beschreibung: The Comprehensive Analytical Model of Rotorcraft Aerodynamics, CAMRAD, program is designed to calculate rotor performance, loads, and noise; helicopter vibration and gust response; flight dynamics and handling qualities; and system aeroelastic stability. The analysis is a consistent combination of structural, inertial, and aerodynamic models applicable to a wide range of problems and a wide class of vehicles. The CAMRAD analysis can be applied to articulated, hingeless, gimballed, and teetering rotors with an arbitrary number of blades. The rotor degrees of freedom included are blade/flap bending, rigid pitch and elastic torsion, and optionally gimbal or teeter motion. General two-rotor aircrafts can be modeled. Single main-rotor and tandem helicopter and sideby-side tilting proprotor aircraft configurations can be considered. The case of a rotor or helicopter in a wind tunnel can also be modeled. The aircraft degrees of freedom included are the six rigid body motion, elastic airframe motions, and the rotor/engine speed perturbations. CAMRAD calculates the load and motion of helicopters and airframes in two stages. First the trim solution is obtained; then the flutter, flight dynamics, and/or transient behavior can be calculated. The trim operating conditions considered include level flight, steady climb or descent, and steady turns. The analysis of the rotor includes nonlinear inertial and aerodynamic models, applicable to large blade angles and a high inflow ratio, The rotor aerodynamic model is based on two-dimensional steady airfoil characteristics with corrections for three-dimensional and unsteady flow effects, including a dynamic stall model. In the flutter analysis, the matrices are constructed that describe the linear differential equations of motion, and the equations are analyzed. In the flight dynamics analysis, the stability derivatives are calculated and the matrices are constructed that describe the linear differential equations of motion. These equations are analyzed. In the transient analysis, the rigid body equations of motion are numerically integrated, for a prescribed transient gust or control input. The CAMRAD program product is available by license for a period of ten years to domestic U.S. licensees. The licensed program product includes the CAMRAD source code, command procedures, sample applications, and one set of supporting documentation. Copies of the documentation may be purchased separately at the price indicated below. CAMRAD is written in FORTRAN 77 for the DEC VAX under VMS 4.6 with a recommended core memory of 4.04 megabytes. The DISSPLA package is necessary for graphical output. CAMRAD was developed in 1980.
    Schlagwort(e): AERODYNAMICS
    Materialart: ARC-12337
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 82
    facet.materialart.
    Unbekannt
    In:  Other Sources
    Publikationsdatum: 2011-08-24
    Beschreibung: ARC2D is a computational fluid dynamics program developed at the NASA Ames Research Center specifically for airfoil computations. The program uses implicit finite-difference techniques to solve two-dimensional Euler equations and thin layer Navier-Stokes equations. It is based on the Beam and Warming implicit approximate factorization algorithm in generalized coordinates. The methods are either time accurate or accelerated non-time accurate steady state schemes. The evolution of the solution through time is physically realistic; good solution accuracy is dependent on mesh spacing and boundary conditions. The mathematical development of ARC2D begins with the strong conservation law form of the two-dimensional Navier-Stokes equations in Cartesian coordinates, which admits shock capturing. The Navier-Stokes equations can be transformed from Cartesian coordinates to generalized curvilinear coordinates in a manner that permits one computational code to serve a wide variety of physical geometries and grid systems. ARC2D includes an algebraic mixing length model to approximate the effect of turbulence. In cases of high Reynolds number viscous flows, thin layer approximation can be applied. ARC2D allows for a variety of solutions to stability boundaries, such as those encountered in flows with shocks. The user has considerable flexibility in assigning geometry and developing grid patterns, as well as in assigning boundary conditions. However, the ARC2D model is most appropriate for attached and mildly separated boundary layers; no attempt is made to model wake regions and widely separated flows. The techniques have been successfully used for a variety of inviscid and viscous flowfield calculations. The Cray version of ARC2D is written in FORTRAN 77 for use on Cray series computers and requires approximately 5Mb memory. The program is fully vectorized. The tape includes variations for the COS and UNICOS operating systems. Also included is a sample routine for CONVEX computers to emulate Cray system time calls, which should be easy to modify for other machines as well. The standard distribution media for this version is a 9-track 1600 BPI ASCII Card Image format magnetic tape. The Cray version was developed in 1987. The IBM ES/3090 version is an IBM port of the Cray version. It is written in IBM VS FORTRAN and has the capability of executing in both vector and parallel modes on the MVS/XA operating system and in vector mode on the VM/XA operating system. Various options of the IBM VS FORTRAN compiler provide new features for the ES/3090 version, including 64-bit arithmetic and up to 2 GB of virtual addressability. The IBM ES/3090 version is available only as a 9-track, 1600 BPI IBM IEBCOPY format magnetic tape. The IBM ES/3090 version was developed in 1989. The DEC RISC ULTRIX version is a DEC port of the Cray version. It is written in FORTRAN 77 for RISC-based Digital Equipment platforms. The memory requirement is approximately 7Mb of main memory. It is available in UNIX tar format on TK50 tape cartridge. The port to DEC RISC ULTRIX was done in 1990. COS and UNICOS are trademarks and Cray is a registered trademark of Cray Research, Inc. IBM, ES/3090, VS FORTRAN, MVS/XA, and VM/XA are registered trademarks of International Business Machines. DEC and ULTRIX are registered trademarks of Digital Equipment Corporation.
    Schlagwort(e): AERODYNAMICS
    Materialart: ARC-12112
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 83
    facet.materialart.
    Unbekannt
    In:  Other Sources
    Publikationsdatum: 2011-08-24
    Beschreibung: Panel methods are moderate cost tools for solving a wide range of engineering problems. PMARC (Panel Method Ames Research Center) is a potential flow panel code that numerically predicts flow fields around complex three-dimensional geometries. PMARC's predecessor was a panel code named VSAERO which was developed for NASA by Analytical Methods, Inc. PMARC is a new program with many additional subroutines and a well-documented code suitable for powered-lift aerodynamic predictions. The program's open architecture facilitates modifications or additions of new features. Another improvement is the adjustable size code which allows for an optimum match between the computer hardware available to the user and the size of the problem being solved. PMARC can be resized (the maximum number of panels can be changed) in a matter of minutes. Several other state-of-the-art PMARC features include internal flow modeling for ducts and wind tunnel test sections, simple jet plume modeling essential for the analysis and design of powered-lift aircraft, and a time-stepping wake model which allows the study of both steady and unsteady motions. PMARC is a low-order panel method, which means the singularities are distributed with constant strength over each panel. In many cases low-order methods can provide nearly the same accuracy as higher order methods (where the singularities are allowed to vary linearly or quadratically over each panel). Low-order methods have the advantage of a shorter computation time and do not require exact matching between panels. The flow problem is solved by assuming that the body is at rest in a moving flow field. The body is modeled as a closed surface which divides space into two regions -- one region contains the flow field of interest and the other contains a fictitious flow. External flow problems, such as a wing in a uniform stream, have the external region as the flow field of interest and the internal flow as the fictitious flow. This arrangement is reversed for internal flow problems where the internal region contains the flow field of interest and the external flow field is fictitious. In either case it is assumed that the velocity potentials in both regions satisfy Laplace's equation. PMARC has extensive geometry modeling capabilities for handling complex, three-dimensional surfaces. As with all panel methods, the geometry must be modeled by a set of panels. For convenience, the geometry is usually subdivided into several pieces and modeled with sets of panels called patches. A patch may be folded over on itself so that opposing sides of the patch form a common line. For example, wings are normally modeled with a folded patch to form the trailing edge of the wing. PMARC also has the capability to automatically generate a closing tip patch. In the case of a wing, a tip patch could be generated to close off the wing's third side. PMARC has a simple jet model for simulating a jet plume in a crossflow. The jet plume shape, trajectory, and entrainment velocities are computed using the Adler/Baron jet in crossflow code. This information is then passed back to PMARC. The wake model in PMARC is a time-stepping wake model. The wake is convected downstream from the wake separation line by the local velocity flowfield. With each time step, a new row of wake panels is added to the wake at the wake separation line. PMARC also allows an initial wake to be specified if desired, or, as a third option, no wakes need be modeled. The effective presentation of results for aerodynamics problems requires the generation of report-quality graphics. PMAPP (ARC-12751), the Panel Method Aerodynamic Plotting Program, (Sterling Software), was written for scientists at NASA's Ames Research Center to plot the aerodynamic analysis results (flow data) from PMARC. PMAPP is an interactive, color-capable graphics program for the DEC VAX or MicroVAX running VMS. It was designed to work with a variety of terminal types and hardcopy devices. PMAPP is available separately from COSMIC. PMARC was written in standard FORTRAN77 using adjustable size arrays throughout the code. Redimensioning PMARC will change the amount of disk space and memory the code requires to be able to run; however, due to its memory requirements, this program does not readily lend itself to implementation on MS-DOS based machines. The program was implemented on an Apple Macintosh (using 2.5 MB of memory) and tested on a VAX/VMS computer. The program is available on a 3.5 inch Macintosh format diskette (standard media) or in VAX BACKUP format on TK50 tape cartridge or 9-track magnetic tape. PMARC was developed in 1989.
    Schlagwort(e): AERODYNAMICS
    Materialart: ARC-12642
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 84
    facet.materialart.
    Unbekannt
    In:  Other Sources
    Publikationsdatum: 2011-08-24
    Beschreibung: The Transonic Airfoil analysis computer code, TAIR, was developed to employ a fast, fully implicit algorithm to solve the conservative full-potential equation for the steady transonic flow field about an arbitrary airfoil immersed in a subsonic free stream. The full-potential formulation is considered exact under the assumptions of irrotational, isentropic, and inviscid flow. These assumptions are valid for a wide range of practical transonic flows typical of modern aircraft cruise conditions. The primary features of TAIR include: a new fully implicit iteration scheme which is typically many times faster than classical successive line overrelaxation algorithms; a new, reliable artifical density spatial differencing scheme treating the conservative form of the full-potential equation; and a numerical mapping procedure capable of generating curvilinear, body-fitted finite-difference grids about arbitrary airfoil geometries. Three aspects emphasized during the development of the TAIR code were reliability, simplicity, and speed. The reliability of TAIR comes from two sources: the new algorithm employed and the implementation of effective convergence monitoring logic. TAIR achieves ease of use by employing a "default mode" that greatly simplifies code operation, especially by inexperienced users, and many useful options including: several airfoil-geometry input options, flexible user controls over program output, and a multiple solution capability. The speed of the TAIR code is attributed to the new algorithm and the manner in which it has been implemented. Input to the TAIR program consists of airfoil coordinates, aerodynamic and flow-field convergence parameters, and geometric and grid convergence parameters. The airfoil coordinates for many airfoil shapes can be generated in TAIR from just a few input parameters. Most of the other input parameters have default values which allow the user to run an analysis in the default mode by specifing only a few input parameters. Output from TAIR may include aerodynamic coefficients, the airfoil surface solution, convergence histories, and printer plots of Mach number and density contour maps. The TAIR program is written in FORTRAN IV for batch execution and has been implemented on a CDC 7600 computer with a central memory requirement of approximately 155K (octal) of 60 bit words. The TAIR program was developed in 1981.
    Schlagwort(e): AERODYNAMICS
    Materialart: ARC-11436
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 85
    facet.materialart.
    Unbekannt
    In:  Other Sources
    Publikationsdatum: 2011-08-24
    Beschreibung: The TAWFIVE program calculates transonic flow over a transport-type wing and fuselage. Although more complex Euler and Navier-Stokes methods are available, TAWFIVE combines a multi-grid acceleration technique in the iterative solution of the potential equation with the use of integral-form boundary-layer equations to provide a computationally efficient and sufficiently accurate design tool. TAWFIVE simplifies the solution process by breaking the problem into a loosely coupled set of modified equations. The inviscid method, using standard inviscid equations (nonlinear full potential), is valid in the "outer" region away from the wing, whereas the boundary-layer equations are valid in the thin region near the solid surface of the wing. The two types of equations are coupled by a technique of modifying surface boundary conditions for the inviscid equations. This interaction process starts with a solution of the outer flow field. Pressures are computed at the wing surface and are used to calculate the boundary layer. The boundary-layer and wake properties are then computed using a three-dimensional integral method, and the computed displacement thickness is added to the surface of the "hard" geometry. This new displaced wing surface is then regridded and the inviscid flowfield is recomputed. New values of the inviscid pressures are then used by the boundary-layer method to predict a new displacement thickness distribution. An under-relaxed update of the previously predicted displacement thickness is then made to obtain a new displacement thickness correction that is added to the "hard" geometry. These global iterations are continued until suitable convergence is obtained. Input to TAWFIVE is limited to geometric definition of the configuration, free-stream flow quantities, and iteration control parameters. The geometric input consists of the definition of a series of airfoil sections to define the wing and a series of fuselage cross sections to model the fuselage. High-aspect-ratio wings are modeled more accurately than low-aspect-ratio wings since no special provisions are made to accurately model the wing-fuselage juncture or the wingtip region. The user can specify the solution either in terms of lift or in terms of angle of attack. TAWFIVE can produce tabular output and input files for PLOT3D (COSMIC program number ARC-12779). TAWFIVE is written in FORTRAN 77 for CRAY series computers running UNICOS. The main memory requirement is 2.7Mb for execution. This program is available on a 9-track 1600 BPI UNIX tar format magnetic tape. TAWFIVE was under development from 1979 to 1989 and first released by COSMIC in 1991. CRAY and UNICOS are registered trademarks of Cray Research, Inc.
    Schlagwort(e): AERODYNAMICS
    Materialart: LAR-14722
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 86
    facet.materialart.
    Unbekannt
    In:  Other Sources
    Publikationsdatum: 2011-08-24
    Beschreibung: This computer program is designed to calculate the flow fields in two-dimensional and three-dimensional axisymmetric supersonic inlets. The method of characteristics is used to compute arrays of points in the flow field. At each point the total pressure, local Mach number, local flow angle, and static pressure are calculated. This program can be used to design and analyze supersonic inlets by determining the surface compression rates and throat flow properties. The program employs the method of characteristics for a perfect gas. The basic equation used in the program is the compatibility equation which relates the change in stream angle to the change in entropy and the change in velocity. In order to facilitate the computation, the flow field behind the bow shock wave is broken into regions bounded by shock waves. In each region successive rays are computed from a surface to a shock wave until the shock wave intersects a surface or falls outside the cowl lip. As soon as the intersection occurs a new region is started and the previous region continued only in the area in which it is needed, thus eliminating unnecessary calculations. The maximum number of regions possible in the program is ten, which allows for the simultaneous calculations of up to nine shock waves. Input to this program consists of surface contours, free-stream Mach number, and various calculation control parameters. Output consists of printed and/or plotted results. For plotted results an SC-4020 or similar plotting device is required. This program is written in FORTRAN IV to be executed in the batch mode and has been implemented on a CDC 7600 with a central memory requirement of approximately 27k (octal) of 60 bit words.
    Schlagwort(e): AERODYNAMICS
    Materialart: ARC-11098
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 87
    facet.materialart.
    Unbekannt
    In:  Other Sources
    Publikationsdatum: 2011-08-24
    Beschreibung: This program was developed to predict turbine stage performance taking into account the effects of complex passage geometries. The method uses a quasi-3D inviscid-flow analysis iteratively coupled to calculated losses so that changes in losses result in changes in the flow distribution. In this manner the effects of both the geometry on the flow distribution and the flow distribution on losses are accounted for. The flow may be subsonic or shock-free transonic. The blade row may be fixed or rotating, and the blades may be twisted and leaned. This program has been applied to axial and radial turbines, and is helpful in the analysis of mixed flow machines. This program is a combination of the flow analysis programs MERIDL and TSONIC coupled to the boundary layer program BLAYER. The subsonic flow solution is obtained by a finite difference, stream function analysis. Transonic blade-to-blade solutions are obtained using information from the finite difference, stream function solution with a reduced flow factor. Upstream and downstream flow variables may vary from hub to shroud and provision is made to correct for loss of stagnation pressure. Boundary layer analyses are made to determine profile and end-wall friction losses. Empirical loss models are used to account for incidence, secondary flow, disc windage, and clearance losses. The total losses are then used to calculate stator, rotor, and stage efficiency. This program is written in FORTRAN IV for batch execution and has been implemented on an IBM 370/3033 under TSS with a central memory requirement of approximately 4.5 Megs of 8 bit bytes. This program was developed in 1985.
    Schlagwort(e): AERODYNAMICS
    Materialart: LEW-14218
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 88
    Publikationsdatum: 2011-08-24
    Beschreibung: Turbomachinery components are often connected by ducts, which are usually annular. The configurations and aerodynamic characteristics of these ducts are crucial to the optimum performance of the turbomachinery blade rows. The ANDUCT computer program was developed to calculate the velocity distribution along an arbitrary line between the inner and outer walls of an annular duct with axisymmetric swirling flow. Although other programs are available for duct analysis, the use of the velocity gradient method makes the ANDUCT program fast and convenient while requiring only modest computer resources. A fast and easy method of analyzing the flow through a duct with axisymmetric flow is the velocity gradient method, also known as the stream filament or streamline curvature method. This method has been used extensively for blade passages but has not been widely used for ducts, except for the radial equilibrium equation. In ANDUCT, a velocity gradient equation derived from the momentum equation is used to determine the velocity variation along an arbitrary straight line between the inner and outer wall of an annular duct. The velocity gradient equation is used with an assumed variation of meridional streamline curvature. Upstream flow conditions may vary between the inner and outer walls, and an assumed total pressure distribution may be specified. ANDUCT works best for well-guided passages and where the curvature of the walls is small as compared to the width of the passage. The ANDUCT program is written in FORTRAN IV for batch execution and has been implemented on an IBM 370 series computer with a central memory requirement of approximately 60K of 8 bit bytes. The ANDUCT program was developed in 1982.
    Schlagwort(e): AERODYNAMICS
    Materialart: LEW-14000
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 89
    facet.materialart.
    Unbekannt
    In:  Other Sources
    Publikationsdatum: 2011-08-24
    Beschreibung: The Panel Code for Planar Cascades was developed as an aid for the designer of turbomachinery blade rows. The effective design of turbomachinery blade rows relies on the use of computer codes to model the flow on blade-to-blade surfaces. Most of the currently used codes model the flow as inviscid, irrotational, and compressible with solutions being obtained by finite difference or finite element numerical techniques. While these codes can yield very accurate solutions, they usually require an experienced user to manipulate input data and control parameters. Also, they often limit a designer in the types of blade geometries, cascade configurations, and flow conditions that can be considered. The Panel Code for Planar Cascades accelerates the design process and gives the designer more freedom in developing blade shapes by offering a simple blade-to-blade flow code. Panel, or integral equation, solution techniques have been used for several years by external aerodynamicists who have developed and refined them into a primary design tool of the aircraft industry. The Panel Code for Planar Cascades adapts these same techniques to provide a versatile, stable, and efficient calculation scheme for internal flow. The code calculates the compressible, inviscid, irrotational flow through a planar cascade of arbitrary blade shapes. Since the panel solution technique is for incompressible flow, a compressibility correction is introduced to account for compressible flow effects. The analysis is limited to flow conditions in the subsonic and shock-free transonic range. Input to the code consists of inlet flow conditions, blade geometry data, and simple control parameters. Output includes flow parameters at selected control points. This program is written in FORTRAN IV for batch execution and has been implemented on an IBM 370 series computer with a central memory requirement of approximately 590K of 8 bit bytes. This program was developed in 1982.
    Schlagwort(e): AERODYNAMICS
    Materialart: LEW-13862
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 90
    Publikationsdatum: 2011-08-24
    Beschreibung: An exact, full-potential-equation model for the steady, irrotational, homoentropic, and homoenergetic flow of a compressible, inviscid fluid through a two-dimensional planar cascade together with its appropriate boundary conditions has been derived. The CAS2D computer program numerically solves an artificially time-dependent form of the actual full-potential-equation, providing a nonrotating blade-to-blade, steady, potential transonic cascade flow analysis code. Comparisons of results with test data and theoretical solutions indicate very good agreement. In CAS2D, the governing equation is discretized by using type-dependent, rotated finite differencing and the finite area technique. The flow field is discretized by providing a boundary-fitted, nonuniform computational mesh. This mesh is generated by using a sequence of conformal mapping, nonorthogonal coordinate stretching, and local, isoparametric, bilinear mapping functions. The discretized form of the full-potential equation is solved iteratively by using successive line over relaxation. Possible isentropic shocks are captured by the explicit addition of an artificial viscosity in a conservative form. In addition, a four-level, consecutive, mesh refinement feature makes CAS2D a reliable and fast algorithm for the analysis of transonic, two-dimensional cascade flows. The results from CAS2D are not directly applicable to three-dimensional, potential, rotating flows through a cascade of blades because CAS2D does not consider the effects of the Coriolis force that would be present in the three-dimensional case. This program is written in FORTRAN IV for batch execution and has been implemented on an IBM 370 series computer with a central memory requirement of approximately 200K of 8 bit bytes. The CAS2D program was developed in 1980.
    Schlagwort(e): AERODYNAMICS
    Materialart: LEW-13854
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 91
    Publikationsdatum: 2011-08-24
    Beschreibung: A computer program, QSONIC, has been developed for calculating the full potential, transonic quasi-three-dimensional flow through a rotating turbomachinery blade row. The need for lighter, more efficient turbomachinery components has led to the consideration of machines with fewer stages, each with blades capable of higher speeds and higher loading. As speeds increase, the numerical problems inherent in the transonic regime have to be resolved. These problems include the calculation of imbedded shock discontinuities and the dual nature of the governing equations, which are elliptic in the subcritical flow regions but become hyperbolic for supersonic zones. QSONIC provides the flow analyst with a fast and reliable means of obtaining the transonic potential flow distribution on a blade-to-blade stream surface of a stationary or rotating turbomachine blade row. QSONIC combines several promising transonic analysis techniques. The full potential equation in conservative form is discretized at each point on a body-fitted period mesh. A mass balance is calculated through the finite volume surrounding each point. Each local volume is corrected in the third dimension for any change in stream-tube thickness along the stream tube. The nonlinear equations for all volumes are of mixed type (elliptic or hyperbolic) depending on the local Mach number. The final result is a block-tridiagonal matrix formulation involving potential corrections at each grid point as the unknowns. The residual of each system of equations is solved along each grid line. At points where the Mach number exceeds unity, the density at the forward (sweeping) edge of the volume is replaced by an artificial density. This method calculates the flow field about a cascade of arbitrary two-dimensional airfoils. Three-dimensional flow is approximated in a turbomachinery blade row by correcting for stream-tube convergence and radius change in the through flow direction. Several significant assumptions were made in developing the QSONIC program, including: (1) the flow is inviscid and adiabatic, (2) the flow relative to the blade is steady, (3) the fluid is a perfect gas with constant specific heat, (4) the flow is isentropic and any discontinuities (shocks) are weak enough to be approximated as isentropic jumps, (5) there is no velocity component normal to the stream surface, and (6) the flow relative to a fixed frame in space (absolute velocity) is completely irrotational. These assumptions place some limitations on the application of QSONIC. Sharp leading edges at high incidence and high-Mach-number turbine blade trailing edges with substantial deviation will both cause large velocity peaks on the blade. In addition, the program may have difficulty converging if the passage is nearly choked. Input to QSONIC consists of case control parameters, a geometry description, upstream boundary conditions, and a rotor description. Output includes solution scheme parameters and flow field parameters. A data file is also output which contains data on the solution mesh, surface Mach numbers, surface static pressures, isomachs, and the velocity vector field. This data may be used for further processing or for plotting. The QSONIC is written in FORTRAN IV for batch execution and has been implemented on an IBM 370 series computer with a central memory requirement of approximately 500K of 8 bit bytes. QSONIC was developed in 1982.
    Schlagwort(e): AERODYNAMICS
    Materialart: LEW-13832
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 92
    Publikationsdatum: 2011-08-24
    Beschreibung: This computer program, WIND, was developed to numerically solve the exact, full-potential equation for three-dimensional, steady, inviscid flow through an isolated wind turbine rotor. The program automatically generates a three-dimensional, boundary-conforming grid and iteratively solves the full-potential equation while fully accounting for both the rotating and Coriolis effects. WIND is capable of numerically analyzing the flow field about a given blade shape of the horizontal-axis type wind turbine. The rotor hub is assumed representable by a doubly infinite circular cylinder. An arbitrary number of blades may be attached to the hub and these blades may have arbitrary spanwise distributions of taper and of the twist, sweep, and dihedral angles. An arbitrary number of different airfoil section shapes may be used along the span as long as the spanwise variation of all the geometeric parameters is reasonably smooth. The numerical techniques employed in WIND involve rotated, type-dependent finite differencing, a finite volume method, artificial viscosity in conservative form, and a successive overrelaxation combined with the sequential grid refinement procedure to accelerate the iterative convergence rate. Consequently, WIND is cabable of accurately analyzing incompressible and compressible flows, including those that are locally transonic and terminated by weak shocks. Along with the three-dimensional results, WIND provides the results of the two-dimensional calculations to aid the user in locating areas of possible improvement in the aerodynamic design of the blade. Output from WIND includes the chordwise distribution of the coefficient of pressure, the Mach number, the density, and the relative velocity components at spanwise stations along the blade. In addition, the results specify local values of the lift coefficient and the tangent and axial aerodynamic force components. These are also given in integrated form expressing the total torque and the total axial force acting on the shaft. WIND can also be used to analyze the flow around isolated aircraft propellers and helicopter rotors in hover as long as the relative oncoming flow is subsonic. The WIND program is written in FORTRAN IV for batch execution and has been implemented on an IBM 370 series computer with a central memory requirement of approximately 253K of 8 bit bytes. WIND was developed in 1980.
    Schlagwort(e): AERODYNAMICS
    Materialart: LEW-13740
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 93
    Publikationsdatum: 2011-08-24
    Beschreibung: This computer program calculates the flow field in the supersonic portion of a mixed-compression aircraft inlet at non-zero angle of attack. This approach is based on the method of characteristics for steady three-dimensional flow. The results of this program agree with those produced by the two-dimensional method of characteristics when axisymmetric flow fields are calculated. Except in regions of high viscous interaction and boundary layer removal, the results agree well with experimental data obtained for threedimensional flow fields. The flow field in a variety of axisymmetric mixed compression inlets can be calculated using this program. The bow shock wave and the internal shock wave system are calculated using a discrete shock wave fitting procedure. The internal flow field can be calculated either with or without the discrete fitting of the internal shock wave system. The influence of molecular transport can be included in the calculation of the external flow about the forebody and in the calculation of the internal flow when internal shock waves are not discretely fitted. The viscous and thermal diffussion effects are included by treating them as correction terms in the method of characteristics procedure. Dynamic viscosity is represented by Sutherland's law and thermal conductivity is represented as a quadratic function of temperature. The thermodynamic model used is that of a thermally and calorically perfect gas. The program assumes that the cowl lip is contained in a constant plane and that the centerbody contour and cowl contour are smooth and have continuous first partial derivatives. This program cannot calculate subsonic flow, the external flow field if the bow shock wave does not exist entirely around the forebody, or the internal flow field if the bow flow field is injected into the annulus. Input to the program consists of parameters to control execution, to define the geometry, and the vehicle orientation. Output consists of a list of parameters used, solution planes, and a description of the shock waves. This program is written in FORTRAN IV for batch execution and has been implemented on a CDC 6000 series machine with a central memory requirement of 110K (octal) of 60 bit words when it is overlayed. This flow analysis program was developed in 1978.
    Schlagwort(e): AERODYNAMICS
    Materialart: LEW-13279
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 94
    Publikationsdatum: 2011-08-24
    Beschreibung: This computer program was developed for calculating the subsonic or transonic flow on the hub-shroud mid-channel stream surface of a single blade row of a turbomachine. The design and analysis of blades for compressors and turbines ideally requires methods for analyzing unsteady, three-dimensional, turbulent viscous flow through a turbomachine. Since an exact solution is impossible at present, solutions on two-dimensional surfaces are calculated to obtain a quasi-three dimensional solution. When three-dimensional effects are important, significant information can be obtained from a solution on a cross-sectional surface of the passage normal to the flow. With this program, a solution to the equations of flow on the meridional surface can be carried out. This solution is chosen when the turbomachine under consideration has significant variation in flow properties in the hubshroud direction, especially when input is needed for use in blade-to-blade calculations. The program can also perform flow calculations for annular ducts without blades. This program should prove very useful in the design and analysis of any turbomachine. This program calculates a solution for two-dimensional, adiabatic shockfree flow. The flow must be essentially subsonic, but there may be local areas of supersonic flow. To obtain the solution, this program uses both the finite difference and the quasi-orthogonal (velocity gradient) methods combined in a way that takes maximum advantage of both. The finite-difference method solves a finite-difference equation along the meridional stream surface in a very efficient manner but is limited to subsonic velocities. This approach must be used in cases where the blade aspect ratios are above one, cases where the passage is curved, and cases with low hub-tip-ratio blades. The quasi-orthogonal method solves the velocity gradient equation on the meridional surface and is used if it is necessary to extend the range of solutions into the transonic regime. In general the blade row may be fixed or rotating and the blades may be twisted and leaned. The flow may be axial, radial, or mixed. The upstream and downstream flow conditions can vary from hub to shroud with provisions made for an approximate correction for loss of stagnation pressure. Also, viscous forces are neglected along solution mesh lines running from hub to tip. The capabilities of this program include handling of nonaxial flows without restriction, annular ducts without blades, and specified streamwise loss distributions. This program is written in FORTRAN IV for batch execution and has been implemented on an IBM 360 computer with a central memory requirement of approximately 700K of 8 bit bytes. This core requirement can be reduced depending on the size of the problem and the desired solution accuracy. This program was developed in 1977.
    Schlagwort(e): AERODYNAMICS
    Materialart: LEW-12966
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 95
    Publikationsdatum: 2011-08-24
    Beschreibung: A computer program has been developed for the design of supersonic rotor blades where losses are accounted for by correcting the ideal blade geometry for boundary layer displacement thickness. The ideal blade passage is designed by the method of characteristics and is based on establishing vortex flow within the passage. Boundary-layer parameters (displacement and momentum thicknesses) are calculated for the ideal passage, and the final blade geometry is obtained by adding the displacement thicknesses to the ideal nozzle coordinates. The boundary-layer parameters are also used to calculate the aftermixing conditions downstream of the rotor blades assuming the flow mixes to a uniform state. The computer program input consists essentially of the rotor inlet and outlet Mach numbers, upper- and lower-surface Mach numbers, inlet flow angle, specific heat ratio, and total flow conditions. The program gas properties are set up for air. Additional gases require changes to be made to the program. The computer output consists of the corrected rotor blade coordinates, the principal boundary-layer parameters, and the aftermixing conditions. This program is written in FORTRAN IV for batch execution and has been implemented on an IBM 7094. This program was developed in 1971.
    Schlagwort(e): AERODYNAMICS
    Materialart: LEW-11744
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 96
    facet.materialart.
    Unbekannt
    In:  Other Sources
    Publikationsdatum: 2011-08-24
    Beschreibung: This program obtains a transonic flow solution on a blade-to-blade surface between blades of a turbomachine. The flow must be essentially subsonic, but there may be locally supersonic flow. The solution is two-dimensional, isentropic, and shock free. The blades may be fixed or rotating. The flow may be axial, radial, or mixed, and there may be a change in stream-channel thickness in the through-flow direction. A loss in relative stagnation pressure may be accounted for. The program input consists of blade and stream-channel geometry, stagnation flow conditions, inlet and outlet flow angles, and blade-to-blade stream-channel weight flow. The output includes blade surface velocities, velocity magnitude and direction at all interior mesh points in the blade-to-blade passage, and streamline coordinates throughout the passage. The transonic solution is obtained by a combination of a finite-difference, stream-function solution and a velocity-gradient solution. The finite-difference solution at a reduced weight flow provides information needed to obtain a velocity-gradient solution. This program is written in FORTRAN IV for batch execution and has been implemented on the IBM 360 computer with a central memory requirement of approximately 36K of 8 bit bytes. This program was developed in 1969 and last updated in 1979.
    Schlagwort(e): AERODYNAMICS
    Materialart: LEW-10977
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 97
    facet.materialart.
    Unbekannt
    In:  Other Sources
    Publikationsdatum: 2011-08-24
    Beschreibung: This program is a revision of an existing program for blade-to-blade aerodynamic analysis of turbomachine blades and it is a simpler program while consistent with related programs. The analysis is for two-dimensional, subsonic, compressible (or incompressible), nonviscous flow in a circular or straight infinite cascade of blades, which may be fixed or rotating. The flow may be axial, radial, or mixed, and the stream channel thickness may change in the through-flow direction. The program input consists of blade and stream channel geometry, total flow conditions, inlet and outlet flow angles, and blade-to-blade stream channel weight flow. The output includes blade surface velocities, velocity magnitude and direction at all interior mesh points in the blade-to-blade passage, and streamline coordinates throughout the passage. This program was developed on an IBM 7094/7044 DCS.
    Schlagwort(e): AERODYNAMICS
    Materialart: LEW-10788
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 98
    Publikationsdatum: 2011-08-24
    Beschreibung: This computer program gives the blade-to-blade solution of the two-dimensional, subsonic, compressible (or incompressible), nonviscous flow problem for a circular or straight infinite cascade of tandem or slotted turbomachine blades. The blades may be fixed or rotating. The flow may be axial, radial , or mixed. The method of solution is based on the stream function using an iterative solution of nonlinear finite-difference equations. These equations are solved using two major levels of iteration. The inner iteration consists of the solution of simultaneous linear equations by successive over-relaxation, using an estimated optimum over-relaxation factor. The outer iteration then changes the coefficients of the simultaneous equations to correct for compressibility. The program input consists of the basic blade geometry, the meridional stream channel coordinates, fluid stagnation conditions, weight flow and flow split through the slot, and inlet and outlet flow angles. The output includes blade surface velocities, velocity magnitude and direction throughout the passage, and the streamline coordinates.
    Schlagwort(e): AERODYNAMICS
    Materialart: LEW-10743
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 99
    facet.materialart.
    Unbekannt
    In:  Other Sources
    Publikationsdatum: 2011-08-24
    Beschreibung: This FORTRAN IV computer program which incorporates the method of characteristics was written to assist in the design of supersonic inlets. There were two objectives: (1) to study a greater variety of supersonic inlet configurations and (2) to reduce the time required for trial-and-error procedures to arrive at optimum inlet design. The computer program was written with the intention of being able to construct a variety of inlet configurations by interchanging specific subroutines. In this manner, greater flexibility of choice was attained, and the time required to program a specific inlet configuration was greatly reduced. The second objective was accomplished by a reformulation of the boundary value problem for hyperbolic equations. By this reformulation of the boundary data, the engineering design quantities, throat Mach number and flow angle, were introduced as direct input quantities to the computer program. As a consequence of introducing the engineering parameters as input, the computer program will calculate the surface contours required to satisfy the specific throat conditions. Inviscid flow is assumed and the method used to calculate the inlet contour results in minimum distortion to the flow in the throat. This program was developed on an IBM 7094.
    Schlagwort(e): AERODYNAMICS
    Materialart: LEW-10868
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 100
    Publikationsdatum: 2011-08-24
    Beschreibung: This program represents a subsonic aerodynamic method for determining the mean camber surface of trimmed noncoplaner planforms with minimum vortex drag. With this program, multiple surfaces can be designed together to yield a trimmed configuration with minimum induced drag at some specified lift coefficient. The method uses a vortex-lattice and overcomes previous difficulties with chord loading specification. A Trefftz plane analysis is used to determine the optimum span loading for minimum drag. The program then solves for the mean camber surface of the wing associated with this loading. Pitching-moment or root-bending-moment constraints can be employed at the design lift coefficient. Sensitivity studies of vortex-lattice arrangements have been made with this program and comparisons with other theories show generally good agreement. The program is very versatile and has been applied to isolated wings, wing-canard configurations, a tandem wing, and a wing-winglet configuration. The design problem solved with this code is essentially an optimization one. A subsonic vortex-lattice is used to determine the span load distribution(s) on bent lifting line(s) in the Trefftz plane. A Lagrange multiplier technique determines the required loading which is used to calculate the mean camber slopes, which are then integrated to yield the local elevation surface. The problem of determining the necessary circulation matrix is simplified by having the chordwise shape of the bound circulation remain unchanged across each span, though the chordwise shape may vary from one planform to another. The circulation matrix is obtained by calculating the spanwise scaling of the chordwise shapes. A chordwise summation of the lift and pitching-moment is utilized in the Trefftz plane solution on the assumption that the trailing wake does not roll up and that the general configuration has specifiable chord loading shapes. VLMD is written in FORTRAN for IBM PC series and compatible computers running MS-DOS. This program requires 360K of RAM for execution. The Ryan McFarland FORTRAN compiler and PLINK86 are required to recompile the source code; however, a sample executable is provided on the diskette. The standard distribution medium for VLMD is a 5.25 inch 360K MS-DOS format diskette. VLMD was originally developed for use on CDC 6000 series computers in 1976. It was originally ported to the IBM PC in 1986, and, after minor modifications, the IBM PC port was released in 1993.
    Schlagwort(e): AERODYNAMICS
    Materialart: LAR-15160
    Format: text
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...