bluuebunny/crossref_metadata_2025_split huggingface dataset:
Production of Exploding Materials for Electro Explosive Devices
Authors: Orbovic Nikola , Luco Ana Cofré , Bozovic Milomir 
Published: August 2008

AbstractThe production of some explosive materials for use in the manufacture of electro explosive devices has been investigated. This work concerns the production of lead salts of some polynitro derivatives of hydroxybenzene (phenol), 1,3‐dihydroxybenzene (resorcinol), and carboxybenzene (benzoic acid), suitable for making fusehead dipping suspensions. During our research, we have discovered that polynitro derivatives of phenol, resorcinol, and benzoic acid react directly with lead oxide in semi‐aprotic solvents such as ethanol or methanol, without the need to convert them to soluble salts. After filtering, washing, and drying (only partially) the products can be used, in wet state for electro explosive device manufacture, without any pretreatment (total drying, screening, or ball grinding). The reactions depend on the acidity of the polynitro derivatives. The effect of different solvents, reaction temperature, procedure, and others, on the product yields and quality has been investigated. The acidity of the polynitro derivatives is the driving force for the reaction. The type of solvent (semi‐aprotic, moderate proton attraction) allows that reactions take place slowly and with uniform particle sizes. The reaction mechanism is discussed. Some of the products obtained in wet state, were used for dipping mixtures and fusehead production. The obtained dipping mixtures have very good stability regarding sedimentation. Fuseheads made with these dipping mixtures have the expected performance.
Malayamycin, a new streptomycete antifungal compound, specifically inhibits sporulation of Stagonospora nodorum (Berk) Castell and Germano, the cause of wheat glume blotch disease
Authors: Li Wenfeng , Csukai Michael , Corran Andrew , Crowley Patrick , Solomon Peter S , Oliver Richard P 
Published: August 2008

AbstractBACKGROUND: Malayamycin is a novel perhydrofuropyran C‐nucleoside isolated from Streptomyces malaysiensis that shows promising antifungal activity, fully controlling a range of diseases when applied to plants at 100 µg mL−1. The goal of this study was to determine the mode of action.RESULTS: Malayamycin exhibited in vitro antifungal activity against Stagonospora nodorum (Berk) Castell & Germano, the cause of stagonospora nodorum blotch of wheat. Growth in liquid minimum medium was merely delayed at 50 µg mL−1, but sporulation was suppressed by more than 50% by 10 µg mL−1 of malayamycin. When applied to wheat seedlings 36 h prior to infection, 10 µg mL−1 of malayamycin reduced lesion size and significantly reduced pycnidiation to only 5% of the non‐treated level. A transcription factor gene, Mrg1 (malayamycin response gene) whose expression was upregulated by application of malayamycin, was identified. Both Mrg1 knockout and overexpression strains were created. These strains were fully pathogenic, suggesting that the expression of Mrg1 did not affect pathogenicity. Interestingly, a strain that expressed Mrg1 50 times more than wild type showed a significant reduction in sporulation. However, all the tested knockout and overexpression strains retained sensitivity to malayamycin.CONCLUSIONS: Malayamycin is a new type of antifungal compound that acts primarily by inhibiting sporulation. Although Mrg1 may be involved in the sporulation process, it is not the major contributor for sporulation inhibition caused by malayamycin treatment. Copyright © 2008 Society of Chemical Industry
Magnetic‐field dependence of electrothermal conductivity in YBCO
Authors: Mariño A. , Uribe R. 
Published: August 2008

AbstractExperimental measurements of the electrothermal conductivity (P) near Tc, as a function of external magnetic field were carried out in undoped YBCO (123) superconducting samples. The electrothermal conductivity which relates electrical and thermal currents, depends on the applied magnetic field in high Tc materials, contrary to conventional low Tc superconductors where P is nearly independent of the magnetic field. The experimental P (B, T) data determined from resistivity and thermopower measurements were analyzed in terms of theoretical models and showed a behavior consistent with an order‐parameter symmetry (OPS) of d‐wave type. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Progress in dye‐sensitized solid state solar cells
Authors: Sirimanne P. M. , Perera V. P. S. 
Published: August 2008

AbstractRecently, dye sensitized solid‐state solar cells with the configuration of n‐semiconductor | sensitizer | hole‐conductor (NDP) have been demonstrated. The maximum power conversion efficiency of this type of solar cells reaches only one third compared to that of dye sensitized photo‐electrochemical cells. The properties of different types of solid‐state dye‐sensitized solar cells are discussed with the aim to understand the mechanisms of operation of these devices. Here we present an overview and the current state of NDP type solar cells based on copper iodide (or copper thiocyanate) as a hole‐conductor. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Origin of the broad lifetime distribution of localized excitons in InGaN/GaN quantum dots
Authors: Winkelnkemper M. , Dworzak M. , Bartel T. P. , Strittmatter A. , Hoffmann A. , Bimberg D. 
Published: August 2008

AbstractWe derive an energy‐dependent decay‐time distribution function from the multi‐exponential decay of the ensemble photoluminescence (PL) of Inx Ga1–x N/GaN quantum dots (QDs), which agrees well with recently published single‐QD time‐resolved PL measurements. Using eight‐band k · p modelling, we show that the built‐in piezo‐ and pyroelectric fields within the QDs cause a sensitive dependence of the radiative lifetimes on the exact QD geometry and composition. Moreover, the radiative lifetimes also depend heavily on the composition of the direct surrounding of the QDs. A broad lifetime distribution occurs even for moderate variations of the QD structure. Thus, for unscreened fields a multi‐exponential decay of the ensemble PL is generally expected in this material system. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Structural, electronic and optical properties of spinel MgAl2O4 oxide
Authors: Hosseini S. M. 
Published: August 2008

AbstractThe structure, band structure, total density of states, dielectric function, reflectivity, refractive index and loss function have been calculated for spinel MgAl2O4 oxide using density functional theory. The full‐potential linearized augmented plane wave method was used with the generalized gradient approximation. Calculations of the optical spectra have been performed for the energy range 0–40 eV. It is shown that the material is transparent at visible wavelengths and the dispersion curve of the refractive index is fairly flat in the long‐wavelength region and rises rapidly towards shorter wavelengths. The refractive index is 1.774 at 800 nm near the visible region. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Impurity effects on Fe‐ or MgO‐doped LiNbO3 crystals studied by 7Li and 93Nb NMR relaxation
Authors: Yeom Tae Ho , Lim Ae Ran , Noiret I. 
Published: August 2008

AbstractThe spin–lattice and spin–spin relaxation times of 7Li and 93Nb nuclei were investigated as a function of the concentration of Fe or MgO species in LiNbO3 crystals using pulse NMR spectrometry. The spin–lattice relaxation times T1 of both nuclei were found to decrease as the number of Fe impurities increased in Fe‐doped LiNbO3 single crystals, because of paramagnetic‐impurity effects. On the other hand, the T1 values of the 7Li and 93Nb nuclei in LiNbO3:MgO crystals remained nearly constant with increasing MgO concentration. The T1 of 7Li was found to be longer than that of 93Nb for both Fe‐ or MgO‐doped single crystals. The spin–spin relaxation times T2 of the 7Li and 93Nb nuclei remained nearly constant with increasing concentration of Fe or MgO. From our results, we can conclude that T1 depends on the concentration of Fe impurities but is independent of the concentration of Mg impurities. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Carrier density and effective mass calculations in carbon nanotubes
Authors: Marulanda Jose M. , Srivastava Ashok 
Published: August 2008

AbstractIn this work, the intrinsic carrier concentration and doping effects have been investigated for different carbon nanotubes. Electronic structure and the density of states functions have been utilized to derive analytical equations for the carrier concentration under high and low doping concentrations. The temperature dependence has also been investigated. The results show how varying diameters and wrapping angles of carbon nanotubes change their concentration profile. The implications of these results allow us to use the same material (carbon nanotube) for a wide range of applications only by varying the chiral vector (n,m). The calculations performed in this work set an upper limit for a wide range of applications including carbon nanotube interconnects and carbon nanotube field effect transistors. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electrodeposition of α‐ and β‐cobalt hydroxide thin films via dilute nitrate solution reduction
Authors: Brownson Jeffrey R. S. , Lévy‐Clément Claude 
Published: August 2008

Abstractα‐ and β‐cobalt hydroxyde thin films were synthesized by cathodic electrodeposition on transparent conductive oxide (TCO) substrates, at 60 °C and 95 °C, respectively, using a very low concentration of Co(NO3)2 and an alkali nitrate supporting electrolyte. Localized cathodic electrochemical generation of hydroxyl species via the reduction of nitrate precursors led to the formation of well crystallized nanostructured films. Scanning Electron Microscopy and X‐ray diffraction confirmed the films were composed of vertically oriented nanoparticle platelets with the c‐axis parallel to the substrate surface, and free of turbostratic disorder. UV/Vis spectra and thermal gravimetric analyses (TGA) indicated variation between the cobalt structures. Films deposited at 60 °C yielded a hydrotalcite‐like compound namely an “hydroxyl‐deficient” [Co(OH)2–x (H2O)x ]x + with NO3– intercalated anion along with water molecules in the interlayer region. Those deposited at 95 °C yielded the brucite β‐Co(OH)2. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Highly active photocatalyst Bix Tiy Vx O4x +2y (x ≈ y) for oxygen evolution under visible‐light illumination
Authors: Liu Haimei , Imanishi Akihito , Nakamura Ryuhei , Nakato Yoshihiro 
Published: August 2008

AbstractA coupled TiO2‐BiVO4 system, Bix Tiy Vx O4x +2y (x ≈ y), with modified TiO2 and BiVO4 crystals through their interaction, was prepared in the form of powder by solid‐state reaction under the concept of combining properties of active photocatalysts. Experiments of photocatalytic oxygen evolution from an aqueous powder suspension under visible‐light irradiation (λ ≥ 420 nm) have shown that Bix Tiy Vx O4x +2y (x ≈ y) exhibits activity much higher than that of BiVO4, which is known as one of the most active visible‐light‐responsive photocatalysts, indicating the effectiveness of the interaction and the modification of TiO2 and BiVO4. XRD experiments showed that Bix Tiy Vx O4x +2y (x ≈ y) was composed of BiVO4 and TiO2 crystals slightly modified probably by partial exchange of V5+ and Ti4+ ions. Photocurrent vs. wavelength for a particulate Bix Tiy Vx O4x +2y (x ≈ y) film electrode demonstrated several components, in agreement with the conclusion that Bix Tiy Vx O4x +2y (x ≈ y) consisted of modified BiVO4 and TiO2 crystals. A possible band model was tentatively proposed to explain observed characteristics such as photocurrent density (j) vs. potential (U), j vs. illumination wavelength (λ), the U dependence of j vs. λ, and the effect of the addition of a reductant such as I−, MeOH, SCN− and Br– on j vs. U and j vs. λ. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Niobium‐doped TiO2 films as window layer for chalcopyrite solar cells
Authors: Neumann Bernhard , Bierau Frauke , Johnson Benjamin , Kaufmann Christian Alexander , Ellmer Klaus , Tributsch Helmut 
Published: August 2008

AbstractSmooth and semitransparent Nbx Ti1–x Oy (x = 0.03, y = 1.84–1.91) films have been prepared by reactive magnetron sputtering at temperatures below 420 K. Structural investigations by RAMAN‐spectroscopy together with resistivity‐ and temperature‐dependent Hall‐measurements were used in order to analyze the film structure and the nature of the charge transport in this material. These films can be used as a window layer (TCO) for thin film solar cells. Cu(In,Ga)Se2 solar cells equipped with the new window layer keep their functionality which excludes first, the presence of strong energetic barriers and second, a strong interfacial recombination. The development of TiO2‐based window layers is expected to make thin film solar cells less sensitive against corrosion after contact with humidity. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Enzyme–semiconductor interactions: Routes from fundamental aspects to photoactive devices
Authors: Lewerenz H. J. 
Published: August 2008

AbstractScanning tunnelling microscopy (STM) experiments at protein–semiconductor systems are analyzed using concepts from applied semiconductor physics such as Fermi level pinning and MIS (metal–insulator–semiconductor) junction electronics. Routes for immobilization of enzymes (proteins) on nanostructured surfaces of MoTe2 and Si are outlined using so‐called DLVO and non‐DLVO interaction forces. An overview of the catalytic activity of the imaged enzymes, reverse transcriptases of the retroviruses HIV 1 and AMV (avian myeloblastosis virus), is given including their tertiary structural properties which is revealed also in the STM and tapping mode AFM images. For the interpretation of STM images, a resonant charge transfer mechanism is invoked, based on the potential dependence of the image contrast and the energy band structure of MoTe2 near the valence band maximum. First analyses of the charge transport from the semiconductor to the STM tip at negative bias of MoTe2 suggest that the observed uninhibited conductivity in the constant current experiments results from solvation‐assisted release of electrons from traps that exist along the polypeptide chains and that charge transport occurs at the circumference of the enzymes where biological water is present. Therefore, charge injection into catalytically active enzymes such as hydrogenase or water oxidase of Photosystem I and II with subsequent charge transport to the active sites appears difficult to realize. Possibilities of radiation‐less long‐distance energy transfer based on the Förster mechanism, its multichromic extension and on Dexter exciton hopping are considered for catalytically active hybrid inorganic/organic absorber–enzyme structures. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Preparation routes based on magnetron sputtering for tungsten disulfide (WS2) films for thin‐film solar cells
Authors: Ellmer K. 
Published: August 2008

AbstractThe semiconductor tungsten disulfide (WS2) exhibits van der Waals bonding, crystallizes in a layer‐type structure and is of interest as an absorber layer for thin‐film solar cells. In this review article different preparation routes for WS2 thin films, based on magnetron sputtering, are reviewed. Films prepared by direct magnetron sputtering, though exhibiting quite a good structural quality, are not or only poorly photoactive. This can be attributed to the generation of recombination centers, especially sulfur vacancies, during the ion bombardment of the films, due to the low defect‐formation energy of tungsten disulfide, an intrinsic property of transition metal dichalcogenides. A promising preparation route, which leads to photoactive WS2 films, is a two‐step process, where, in a first step, a sulfur‐rich, X‐ray amorphous tungsten sulfide is deposited at low substrate temperatures onto a thin metal film (Ni, Co). This film sandwich is after wards annealed in an ampoule in a sulfur atmosphere or in flowing gas with a sufficient H2S partial pressure. From in‐situ transmission electron microscopy and energy‐dispersive X‐ray diffraction, it was found that the WS2 film crystallization with a pronounced (001) texture is closely related to the formation of the liquid (eutectic) metal–sulfur phase. Based on these in‐situ investigations the growth of the 2‐dimensional WS2 nanosheets from an amorphous WS3+x precursor can be described as an amorphous solid‐liquid‐crystalline solid process (SLS), somewhat similar to the well‐known vapor‐liquid‐solid (VLS) process for the growth of whiskers or nanorods and nanotubes. Research opportunities, to overcome current limitations for a broad use of WS2 (and MoS2) as thin‐film solar cell absorbers are given. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On the homogeneity region, growth modes and optoelectronic properties of chalcopyrite‐type CuInS2
Authors: Fiechter Sebastian , Tomm Yvonne , Kanis Michael , Scheer Roland , Kautek Wolfgang 
Published: August 2008

AbstractStudying the pseudo‐binary phase diagrams of Cu2S–In2S3 and CuS–InS in the ternary system Cu–In–S showed that the CuInS2 compound semiconductor exhibits a melting point at T = 1093(±3) °C and a homogeneity region at room temperature ranging from 2 mol% in In2S3 to 1.5 mol% in the CuS direction. This material, which crystallizes in the chalcopyrite‐type structure, occurs in nature as the mineral roquésite. Investigating the influence of inert gas pressure on the crystallization of a stoichiometric melt, a disproportionation of the crystallized material into a Cu2S‐rich bulk material of composition Cu1.06In0.98S2 epitaxially intergrown with ∼1.5 µm thick lamellae of the thiospinel phase CuIn5S8 was observed. Structure and composition of the bulk material were characterized by applying scanning Auger microscopy (SAM) and scanning electron microscopy (SEM) as well as differential thermal analysis (DTA) and X‐ray diffractometry (XRD). In photoluminescence measurements (PL), Cu‐rich bulk material is distinguished by sharp emission lines representing excitons close to the band to band transition at 1.55 eV and a broadband emission in the range from 1.3 eV to 1.45 eV. Exciton peaks of highest intensity were found at a Cu:In ratio = 1.0524. Investigating the spectral response of thin film chalcopyrite solar cells, a significant change of the optical gap from 1.45 eV for a “Cu‐rich” to 1.37 eV for an “In‐rich” absorber layer was observed. The results show that the homogeneity region of the material can be varied in the percentage range. A shift of the optical band gap can be influenced by stoichiometry (at% sulphur: at% metal) and the crystallization conditions of the adamantine‐type structure. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effect of different doses of Manuka honey in experimentally induced inflammatory bowel disease in rats
Authors: Prakash A. , Medhi B. , Avti P. K. , Saikia U. N. , Pandhi P. , Khanduja K. L. 
Published: August 2008

AbstractTo evaluate the effect of different doses of Manuka honey in experimentally induced inflammatory bowel disease in rats. Adult Wistar rats of either sex were used (n = 30). Colitis was induced by a single intracolonic administration of TNBS dissolved in 35% ethanol. The rats (n = 30) were divided into five groups (n = 6) and were treated with vehicle (ethanol), TNBS, Manuka honey (5 g/kg, p.o.), Manuka honey (10 g/kg, p.o.) or sulfasalazine (360 mg/kg, p.o.) body weight for 14 days. After completion of treatment, the animals were killed and the following parameters were assessed: morphological score, histological score and different antioxidant parameters.Manuka honey at different doses provided protection against TNBS‐induced colonic damage. There was significant protection with Manuka honey 5 g/kg as well as with 10 g/kg body weight compared with the control (p < 0.001). All the treated groups showed reduced colonic inflammation and all the biochemical parameters were significantly reduced compared with the control in the Manuka honey treated groups (p < 0.001). Manuka honey at different doses restored lipid peroxidation as well as improved antioxidant parameters. Morphological and histological scores were significantly reduced in the low dose Manuka honey treated group (p < 0.001). In the inflammatory model of colitis, oral administration of Manuka honey 5 g/kg and Manuka honey 10 g/kg body weight significantly reduced the colonic inflammation. The present study indicates that Manuka honey is efficacious in the TNBS‐induced rat colitis model, but these results require further confirmation in human studies. Copyright © 2008 John Wiley & Sons, Ltd.
Effect of Tilia × viridis flower extract on the proliferation of a lymphoma cell line and on normal murine lymphocytes: contribution of monoterpenes, especially limonene
Authors: Manuele Maria Gabriela , Ferraro Graciela , Anesini Claudia 
Published: August 2008

AbstractTilia species are widely used in Europe as medicinal plants. The selective antiproliferative activity of a Tilia cordata flower dichloromethane extract (DME) on a lymphoma cell line has been reported previously and in order to extend this to other unstudied Tilia species, the effect of Tilia × viridis DME on the proliferation of tumor and normal murine lymphocytes was investigated. The bioguided fractionation of DME yielded a fraction rich in limonene (L), α‐pinene and β‐pinene, which presented a selective antiproliferative action on tumor lymphocytes (EC50 on tumor cells: 3.8 ± 0.2 µg/mL; EC50 on normal cells: 205 ± 1.8 µg/mL). While all monoterpenes exhibited this activity, limonene proved to be the most active (EC50 on tumor cells: 35 ± 2.0 µg/mL; EC50 on normal cells: 72 ± 5.0 µg/mL) also exerting a stimulatory effect on non‐mitogen stimulated lymphocytes proliferation (% of stimulation respect to control) (mean ± SEM): L 10 µg/mL: 25 ± 1.0%; 20 µg/mL: 38.5 ± 2.5%; L 40 µg/mL: 41 ± 0.9%; L 60 µg/mL: 58.5 ± 3%. T. × viridis may thus constitute a potential source of monoterpenes with immunomodulatory activity. Copyright © 2008 John Wiley & Sons, Ltd.
The effects of Alcea rosea L., Malva sylvestris L. and Salvia libanotica L. water extracts on the production of Anti‐egg albumin antibodies, interleukin‐4, gamma interferon and interleukin‐12 in BALB/c mice
Authors: Ghaoui Walid Bou Jaber El , Ghanem Elsa Bou , Chedid Lara Abou , Abdelnoor Alexander M. 
Published: August 2008

AbstractPolysaccharides obtained from certain plants have been reported to have immunomodulatory properties. As a consequence of these reports the aim of this study was to investigate some immunomodulatory properties of water extracts of Alcea rosea L. (ARE), Malva sylvestris L. (MSE) and Salvia libanotica L. (SLE).Groups of egg albumin (EA)‐immunized and ‐non‐immunized Balb/c mice were treated with the carbohydrate‐rich water extracts. Mice from each group were bled and their spleens removed at 3, 6 and 10 days post‐immunization/treatment. Anti‐egg albumin antibody levels in the processed sera were determined by an enzyme linked immunosorbent assay (ELISA). RNA was extracted from spleen cells and interleukin‐4 (IL‐4), interleukin‐12 (IL‐12) and γ‐interferon transcripts were determined by the reverse transcription polymerase chain reaction (RT‐PCR).ARE appeared to boost the antibody response to EA, but had no effect on IL‐4 and γ‐interferon gene transcription. MSE and SLE appeared to have no effect on anti‐EA antibody production, but enhanced IL‐12 and γ‐interferon gene transcription. MSE appeared to switch off, and SLE had no effect on, IL‐4 transcription.In conclusion, it appears that ARE is a B‐lymphocyte polyclonal activator, and MSE and SLE are macrophage and T helper‐1 (Th‐1) activators. Copyright © 2008 John Wiley & Sons, Ltd.