ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

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
  • Artikel  (31)
  • Chemical Engineering  (27)
  • Aerospace Medicine
  • Curculionidae
  • ELECTRONIC SYSTEMS
  • FLUID MECHANICS AND HEAT TRANSFER
  • 2005-2009
  • 1990-1994  (20)
  • 1970-1974  (11)
Sammlung
Schlagwörter
Verlag/Herausgeber
Erscheinungszeitraum
Jahr
  • 1
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 1789-1800 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: The finite element method was used to model microwave thawing of pure-water and 0.1-M NaCl cylinders. The electromagnetic field was described by Maxwell's equations with temperature-dependent dielectric properties, while the heat equation, coupled with the Stefan and Robin conditions, was used to describe the thawing process. An additional equation for the frozen volume fraction was used, when necessary, to account for the presence of a mushy region. Two microwave frequencies, 915 MHz and 2,450 MHz, were examined and the microwave radiation was assumed to be radially isotropic and normal to the surface of the cylinder. Results show that a two-phase mushy region may exist, and an additional thawing front may appear at the center of the cylinder. Salt cylinders have a higher dielectric loss than pure-water cylinders and therefore thaw more quickly. Internal resonance occurs when the wavelength of the radiation is a harmonic of the cylinder radius. Resonance increases power deposition and expedites the thawing process. The onset of resonance alters thawing times and complicates the development of heuristic rules for microwave thawing.
    Zusätzliches Material: 12 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 2
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 40 (1994), S. 1433-1439 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: It is generally believed that oil samples heat faster in a microwave oven than do water samples of the same mass. For sufficiently large and thich samples this conventional wisdom is indeed correct, but this trend can be far from true in smaller samples. In a commercially-made home microwave oven, we observed that with decreasing sample size the heating rate of a water sample increases much faster than that of an oil sample. At 50 g the heating rate of a water sample is several times greater than that of an oil sample. Additionally, in studies of cylindrical samples in a customized oven having a unidirectional microwave source, the heating rate of water samples smaller than 2.4 cm in radius is greater than that of oil samples and is a strongly oscillatory increasing function of decreasing sample radius. Combining Maxwell's theory of microwave penetration and the heat conduction equation, we show that this previously unreported oscillatory heating behavior results from the added power absorbed by samples due to resonant absorption of microwaves. The added power arises from standing waves produced by internally reflected microwaves. This effect is small for oil because only 3% of the microwave power is reflected at an oil-air interface. On the other hand, 64% is reflected at a water-air interface, which causes strong resonant heating. Our findings might prove to be useful for future consumer food product development or oven design.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 3
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 313-322 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Transient temperature profiles in multilayer slabs are predicted, by simultaneously solving Maxwell's equations with the heat conduction equation, using Galerkin finite elements. It is assumed that the medium is homogeneous and has temperature-dependent dielectric and thermal properties. The method is illustrated with applications involving the heating of food and polymers with microwaves. The temperature dependence of dielectric properties affects the heating appreciably, as is shown by comparison with a constant property model.
    Zusätzliches Material: 7 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 4
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 38 (1992), S. 1577-1592 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Transient temperature profiles for long rods of lossy dielectric materials with thermally-dependent dielectric properties exposed to uniform plane waves are obtained. Maxwell's equation and the heat equation are simultaneously solved using the finite element method to predict the power absorbed and the resulting temperature rise in samples of square and circular cross-section. Following the method introduced recently, we derive an exact radiation boundary condition which is independent of the rod cross-section. For a cylindrical sample, the boundary condition is imposed on the cylinder itself. For a square rod, the boundary condition is imposed on a cylinder containing the rod. The temperature dependence of dielectric properties and sample dimensions appreciably influence heating patterns. For square samples, the edges focus radiation, causing preferential heating at the edges. This effect is pronounced for larger samples. In addition, the incident wave polarization influences the heating of the rod. For waves where the electric field is polarized along the long axis of the sample (TMz polarization) the power absorbed is higher than when the electric field is perpendicular to the axis (TEz polarization). A case involving runaway heating is also investigated.
    Zusätzliches Material: 9 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 5
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 40 (1994), S. 1268-1272 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Zusätzliches Material: 7 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 6
    ISSN: 1573-1561
    Schlagwort(e): Coleoptera ; Curculionidae ; Rhynchophorus cruentatus ; palmetto weevil ; S. palmetto ; aggregation pheromone ; 5-methyl-4-octanol ; cruentol
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract 5-Methyl-4-octanol is the major aggregation pheromone of the palmetto weevil,Rhynchophorus cruentatus (F.). The pheromone (cruentol) was identified by coupled gas chromatographic-electroantennographic (GC-EAD) analysis of male-produced volatiles, coupled GC-mass spectrometry (MS) in electron impact and chemical ionization mode, and coupled GC-high resolution MS. In laboratory and field assays, a diastereomeric mixture of synthetic cruentol greatly enhanced attraction of weevils to cabbage palmetto,Sabal palmetto (Walter), stem tissue, indicating that cruentol and host volatiles are synergistically attractive. An attractive lure in combination with efficient traps should facilitate development of semiochemical-based management forR. cruentatus.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 7
    ISSN: 1573-1561
    Schlagwort(e): Coleoptera ; Curculionidae ; Rhynchophorus cruentatus ; Sabalpalmetto ; aggregation pheromone ; olfactometer ; field trapping
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Laboratory and field assays were conducted to determine if palmetto weevil,Rhynchophorus cruentatus (F.), adults produce an aggregation pheromone. Attraction of females in a Y-tube olfactometer to conspecific males was greater than to clean air. Male and female attraction to conspecific male volatiles combined with host-palm,Sabal palmetto (Walter), volatiles was greater than to host-palm volatiles alone. Similarly, more weevils were caught in the field in traps baited with conspecific males plus host-palm tissue than in similar traps baited with only males, or palm tissue, or females, or females plus palm tissue. These results suggest thatR. cruentatus males produce an aggregation pheromone(s) that is highly attractive to conspecific adults of both sexes when combined with host-palm volatiles. This study is an important step towards understanding the chemical ecology ofR. cruentatus.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 8
    ISSN: 1573-1561
    Schlagwort(e): Coleoptera ; Curculionidae ; Rhynchophorus phoenicis ; Rhynchophorus cruentatus ; aggregation pheromone ; pheromone chirality ; (3S,4S)-3-methyl-octan-4-ol ; (3R,4R)-3-methyl-octan-4-ol ; (3S,4R)-3-methyl-octan-4-ol ; (3R,4S)-3-methyl-octan-4-ol ; (4S,5S)-5-methyl-octan-4-ol ; (4R,5R)-5-methyl-octan-4-ol ; (4S,5R)-5-methyl-octan-4-ol ; (4R,5S)-5-methyl-octan-4-ol
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract There are four stereoisomers of both 3-methyl-octan-4-ol, the aggregation pheromone of the African palm weevil,Rhynchophorus phoenicis (F.) and 5-methyl-octan-4-ol, the aggregation pheromone of the palmetto weevil,Rhynchophorus cruentatus (F.). Synthetic stereoisomers of 3-methyl-octan-4-ol and 5-methyl-octan-4-ol were baseline-separated on a Cyclodex-B fused silica column. Use of this column in gas chromatographic-electroantennographic detection (GC-EAD) and GC-mass spectrometric (GC-MS) analyses revealed that only one stereoisomer, (3S,4S)-3-methyl-octan-4-ol and (4S,5S)-5-methyl-octan-4-ol, is produced by maleR. phoenicis and maleR. cruentatus, respectively, and elicits good antennal responses by conspecific male and female weevils. In field trapping experiments, withR. phoenicis in Côte d'Ivoire andR. cruentatus in Florida, (3S,4S)-3-methyl-octan-4-ol and (4S,5S)-5-methyl-octan-4-ol strongly enhanced attraction of fresh palm tissue, whereas other stereoisomers were behaviorally benign. Stereoisomeric 3-methyl-octan-4-ol and 5-methyl-octan-4-ol may be utilized to monitor and/or manage populations of these two palm weevils.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 9
    ISSN: 1573-1561
    Schlagwort(e): Attractant ; alcohol ; aldehyde ; geranic acid ; monitoring ; aggregation pheromone ; Anthonomus eugenii ; pepper weevil ; Coleoptera ; Curculionidae
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract This study describes the identification of an aggregation pheromone for the pepper weevil,Anthonomus eugenii and field trials of a synthetic pheromone blend. Volatile collections and gas chromatography revealed the presence of six male-specific compounds. These compounds were identified using chromatographic and spectral techniques as: (Z)-2-(3,3-dimethylcyclohexylidene)ethanol, (E)-2-(3,3-dimethylcyclohexylidene)ethanol, (Z)-(3,3-dimethylcyclohexylidene)acetaldehyde, (E)-(3,3-dimethylcyclohexylidene)acetaldehyde, (E)-3,7-dimethyl-2,6-octadienoic acid (geranic acid), and (E)-3,7-dimethyl-2,6-octadien-1-ol (geraniol). The emission rates of these compounds from feeding males were determined to be about: 7.2, 4.8, 0.45, 0.30, 2.0, and 0.30µg/male/day, respectively. Sticky traps baited with a synthetic blend of these compounds captured more pepper weevils (both sexes) than did unbaited control traps or pheromone-baited boll weevil traps. Commercial and laboratory formulations of the synthetic pheromone were both attractive. However, the commercial formulation did not release geranic acid properly, and geranic acid is necessary for full activity. The pheromones of the pepper weevil and the boll weevil are compared. Improvements for increasing trap efficiency and possible uses for the pepper weevil pheromone are discussed. A convenient method for purifying geranic acid is also described.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 10
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 1905-1905 
    ISSN: 0001-1541
    Schlagwort(e): Chemistry ; Chemical Engineering
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...