ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • American Institute of Physics (AIP)  (380)
  • Springer Science + Business Media  (182)
  • 1
    Publication Date: 2014-04-01
    Description: PurposeWhen dealing with remediation projects in zones affected by mining activities, the risk posed by the ingestion of the plants by fauna is often forgotten. The purpose of this study is the assessment of arsenic assimilation by the natural vegetation in these areas. To study the transfer to the trophic chain two mammals, the sheep and the vole are selected. The risk analysis is founded on the contribution of these natural plants to the ingestion.Material and methodsSoil samples and the same number of plants (165) growing in the soils were collected in an old mining area in the southeast of Spain. Physico-chemical properties were calculated by means of the usual procedures. To determine the arsenic content, the soil samples and plant materials were digested by means of a microwave system and the arsenic concentration was determined using atomic fluorescence spectrometry with automated continuous flow hydride generation (HG-AFS). A semiquantitative estimation of the mineralogical composition of the samples was made by X-ray diffraction analysis.Results and discussionThe mineralogy and As content of the soils studied depends on the materials related with the mining activity. The descriptive statistical analysis of the population of plants studied points to an As range of 0.31–150 mg/kg in roots, although the concentration in shoots was lower (0.21–83.4 mg/kg). Bioconcentration (BCF) and transfer factors (TF) were studied for each plant species and soil type on which it grew. The results show that As transfer depends on the plant species and the characteristics of the soil. The potential risk of As entering the food chain through the plant species was evaluated. The exposure pathway considered was oral ingestion, calculating the contribution of the plant to the daily dose based on the arsenic concentration in the shoots of the plants analysed.ConclusionsIn the samples studied, the levels of As in roots were higher than in shoots, and increased with the As concentration in the soil. The BCFs were generally very low, and the TFs while slightly higher, seldom exceeded unity. When undertaking with the phytoremediation of contaminated sites, the contribution of the As level in plants to the daily diet of animals should be used as an indicator for the screening of the vegetal species to be used. ©2014 Springer-Verlag Berlin Heidelberg
    Print ISSN: 1439-0108
    Electronic ISSN: 1614-7480
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Geosciences
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 76 (2000), S. 3274-3276 
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Moderate pressure techniques (P=20 kbar) have been used to prepare Tl2−xCdxMn2O7 (0≤x≤0.4) pyrochlore-like materials. The x=0.2 compound has been characterized by neutron powder diffraction, magnetic, magnetotransport, and Hall measurements. This material is ferromagnetic below TC=110 K. Both electrical resistance and magnetoresistance (MR) are enhanced with respect to stoichiometric Tl2Mn2O7, due to the drastic reduction in the number of carriers (electrons) induced by hole doping. MR(0.5 T) is higher than 106% at 120 K, and MR(9 T) is 30% at room temperature. We show that hole doped derivatives of Tl2Mn2O7 are promising candidates in which to search for large bulk magnetoresistance. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 64 (1993), S. 2147-2152 
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: We describe a spectrometer (visible-ultraviolet photon energy range) for the measurement of reflectance-difference spectra of cubic semiconductors. The spectrometer employs a photoelastic modulator to modulate the polarization of the light incident on the sample and allows for a simple procedure to correct the measured spectra for parasitic components associated with such modulation. The instrument reported has a higher throughput than more conventional setups. To illustrate the spectrometer performance we report on reflectance-difference spectra of (001) oriented GaAs single crystals doped with silicon donors at a level of 1018/cm3.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The magnetic properties of a stoichiometric Pr2NiO4 single crystal have been examined by means of the temperature dependence of the complex ac susceptibility and the isothermal magnetization in fields up to 200 kOe at T=4.2 K. Three separate phases have been identified and their anisotropic character has been analyzed. A collinear antiferromagnetic phase appears first between TN = 325 K and Tc1 = 115 K, where the Pr ions are polarized by an internal magnetic field. At Tc1 a first modification of the magnetic structure occurs in parallel with a structural phase transition (Bmab to P42/ncm). This magnetic transition has a first-order character and involves both the out-of-plane and the in-plane spin components (magnetic modes gx and gxcyfz, respectively). A second magnetic transition having also a first-order character is also clearly identified at Tc2 = 90 K which corresponds to a spin reorientation process (gxcyfz to cxgyaz magnetic modes). It should be noted as well that the out-of-phase component of χac shows a peak around 30 K which reflects the coexistence of both magnetic configurations in a wide temperature interval. Finally, two field-induced transitions have been observed at 4.2 K when the field is directed along the c axis. We propose that the high-field anomaly arises from a metamagnetic transition of the weak ferromagnetic component, similarly to La2CuO4.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Publication Date: 2015-11-06
    Description: In this work, the influence of applied load on the frictional behavior of alkyl acrylate copolymer elastomers coated with diamond-like carbon films is studied at dry conditions. The performance of two coatings with very different microstructure (patched vs. continuous film) is compared with the uncoated substrate. A wide range of applied loads is explored, from 1 mN to 1 N, which is achieved by using a specific tribometer. The variation of 3 orders of magnitude in the applied load leads to a strong variation of the observed frictional phenomena. The different behavior of both samples at various loads is explained using a model that considers two contributions to the friction coefficient, namely, an adhesive and a rubber hysteresis part. The constraints and applicability of such model are critically evaluated.
    Print ISSN: 0021-8979
    Electronic ISSN: 1089-7550
    Topics: Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Publication Date: 2014-07-25
    Description: We calculate negative moments of the N -dimensional Laguerre distribution for the orthogonal, unitary, and symplectic symmetries. These moments correspond to those of the proper delay times, which are needed to determine the statistical fluctuations of several transport properties through classically chaotic cavities, like quantum dots and microwave cavities with ideal coupling.
    Print ISSN: 0022-2488
    Electronic ISSN: 1089-7658
    Topics: Mathematics , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Publication Date: 2014-11-07
    Description: In this work, we report on photoreflectance (PR) and photoreflectance-difference (PR-D) measurements of GaAs(001) upon deposition of Gd 2 O 3 thin films. The study is focused on two different substrates: a semi-insulating (SI) with Cr impurities and a Si-doped n -type. PR-D results show that Gd 2 O 3 induces a tensile strain on the GaAs surface and a direct piezo-electric dipole is created. Such strain changes the crystal symmetry from cubic to orthorhombic and renders the quadratic electro-optic (QEO) component anisotropic. For the SI substrate, both linear electro-optic (LEO) and QEO components contribute to the PR-D spectrum, whereas the n -type PR-D spectrum is dominated by the LEO component. In both cases, a tensile strain induces a rigid redshift of ∼20 meV to low energies of the E 1 and E 1  + Δ 1 optical transitions.
    Print ISSN: 0003-6951
    Electronic ISSN: 1077-3118
    Topics: Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Publication Date: 2014-04-01
    Description: PurposeGreen areas in urban parks are special ecosystems because of social and ecological benefits.Materials and methodsWe investigated the ecological impacts of green spaces by comparing the properties of soils, with emphasis on metals, in green spaces and bare soil playgrounds in four urban parks in Murcia City (SE Spain).Results and discussionOrganic matter (OM) contents in green areas are higher than playground soils due to litter decomposition from grass. Cation exchange capacity in green areas ranged from 10 to 14 compared to 2 cmol+kg−1 in playground soils, showing the effect of OM (and clay) contents in green areas due to the presence of vegetation. Soil total metal contents in urban parks are below the environmental threshold values for soils in Spain and other European countries, and come from atmospheric deposition and fertilizers application. Diethylenetriaminepentaacetic acid (DTPA)-extractable soil Cd in green areas (4% of total Cd) is lower than in playground soils (58% of total Cd). We attributed the reduced DTPA- and water-extractable Cd, Co, Cr, Mn, and Mo to the formation of stable complexes between metals and OM produced from the continued decomposition of roots of grasses in green spaces.ConclusionsGrasses accumulate less metal than soils except in roots where Cr and Zn are higher than soils by as much as 31 and 17%, respectively. We conclude that grasses increased (up to 8×) soil OM content in green areas to significantly increase the ability of soils to accumulate nutrients for plants, and to retain and reduce the mobility and toxicity of metals in soils in urban parks. ©2014 Springer-Verlag Berlin Heidelberg
    Print ISSN: 1439-0108
    Electronic ISSN: 1614-7480
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Geosciences
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    Publication Date: 1995-02-01
    Description: Synkinematic quartz veins are ubiquitous in the shear zone separating the Veleta unit from the Calar Alto unit in the internal part of the Betic Cordilleras. They have been studied with respect to quartz c-axis fabrics, microstructures and fluid inclusions. Veins were probably generated during syn-metamorphic stacking of the units at P = 500 − 600 MPa and T = 400 − 500°C. Quartz displays two groups of microstructures in the shear zone: (1) older coarse-grained mosaics (CGM) resulting from exaggerated grain growth; and (2) younger fine-grained mosaics (FGM) developed at the expense of the former. The fine-grained mosaics show polygonal granoblastic and elongate mosaic microstructures in general, with ribbon microstructures often found near the boundary of the units. Fluids contained in secondary inclusions vary from high salinity brines to different types of CO2—brine mixtures and low density CO2 fluids. Differences in composition and P-T trapping conditions are indicated for the different types of inclusions. Some fluid inclusions are older than the FGM, whereas others are younger, thus constraining the P- T conditions at which the two microstructural events took place. Fluid inclusion evidence suggests conditions of Pfluid 〉 170 MPa and T ≧ 370−430°C for the CGM and Pfluid ≧ 20−80 MPa and T 〉 340°C for the FGM. The quartz c-axis fabrics dealt with here correspond to the second recrystallization event, as little evidence of older fabrics is preserved in the shear zone. C-axis patterns vary across the shear zone from slightly asymmetrical type I crossed girdles in the hanging wall and footwall to more asymmetrical crossed girdles at the boundary of the units. This indicates a correlative increase in the magnitude of the heterogeneous shear strain in the same direction. Most of the deformation is concentrated at the top of the Veleta unit. The sense of movement is top to the west, in agreement with other kinematic markers. The quartz c-axis fabrics resulted from dynamic recrystallization during simple shear. The retrograde P-T path inferred from fluid inclusion analysis, along with other geological and geochronological evidence, indicates that this deformation is coeval with a reduction in the crustal overburden. Geochronological and stratigraphic data show that the proposed Dos Picos extensional detachment, separating the Calar Alto and Veleta units, took place during the early Miocene, synchronous with the intense thinning of the Nevado-Filábride Complex and of the whole continental crust underlying the Alborán Basin. ©1995 Springer-Verlag
    Print ISSN: 1437-3254
    Electronic ISSN: 1437-3262
    Topics: Geosciences
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    Publication Date: 2016-05-21
    Description: Nowadays, solar resource estimation via clear-sky models is widely accepted when correctly validated with on ground records. In the past, different approaches have been proposed in order to determine clear-sky periods of solar radiation on-ground records: visual inspection of registers, discretization via a threshold value of clear sky index, and correlation with estimated clear sky solar irradiation. However, due to the fact that the process must be automated and the need for universality, the search for clear-sky conditions presents a challenging feat. This study proposes a new algorithm based on the persistent value of the Linke turbidity in conjunction with a transitory filter. The determinant of the correlation matrix of estimated clear-sky solar irradiance and measured irradiance is calculated to distinguish between days under clear-sky conditions and cloudy or overcast days. The method was compared and proved superior against a review of other 10 commonly used techniques at 21 sites of the Baseline Surface Radiation Network, which includes diverse climates and terrain.
    Electronic ISSN: 1941-7012
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...