bluuebunny/crossref_metadata_2025_split huggingface dataset:
‘Vive la différence?’: The ‘international’ experiences of UK students overseas
Authors: Waters Johanna , Brooks Rachel 
Published: March 2010

AbstractAs interest in the geographies of student mobilities grows, this paper examines the experiences of UK students overseas. More specifically, it considers the ‘international’ nature of their experiences, asking: to what extent do students actively seek out and encounter ‘cultural difference’ through their educational choices? International students are often described by those advocating the internationalisation of education as potential ‘global citizens’, cosmopolitans and ambassadors of inter‐cultural understanding. However, our research on UK students has suggested a more complex engagement with ‘diversity’ through international education. First, we examine the motivations of UK students, and show that whilst many claim to be seeking ‘something different’ from an overseas education, at the same time they also desire a ‘knowable’ destination. Film and television were very significant in terms of making certain places familiar to students and thereby influencing their decisions. Secondly, students' experiences of cultural diversity overseas were often confined to an international student community. This has several implications. Most obviously, it limits the extent to which students encounter cultures ‘local’ to the destination country. The separation and isolation of the international student community, however, does serve a useful function in terms of wider processes of elite class formation and social reproduction. Thirdly, we describe some instances of where individuals formed significant and meaningful relationships with foreign nationals, often as a direct consequence of their experiences of studying overseas. Clearly, this suggests a very direct engagement with ‘cultural diversity’, albeit of a certain kind. Copyright © 2010 John Wiley & Sons, Ltd.
Manipulating emission of CdTeSe quantum dots embedded in synthetic opals
Authors: Vion C. , Barthou C. , Benalloul P. , Schwob C. , Coolen L. , Gruzintsev A. N. , Emelchenko G. A. , Masalov W. M. , Frigerio J.‐M. , Maitre A. 
Published: March 2010

AbstractPhotonic crystals (PCs) are the object of great interest due to the possibility, for appropriate PCs, to modify and control light propagation and even to influence the emission properties of an emitter, such as its emission diagram and its life time. One of the most common approaches to prepare 3D PCs takes advantage of the spontaneous self‐organisation of spherical colloidal particles. Large opals have been prepared by the sedimentation method and the size of the balls has been adjusted so that the pseudo‐band gap of those PCs lies in the same region than the emission band of CdSe/ZnS nanocrystals. Diagrams of radiation and the modification of the spontaneous life time of the embedded nanocrystals will be presented and discussed. It is found that, for the opal‐CdSe/ZnS nanocomposites, the emission intensity decreases and the luminescence decay time increases in the spatial directions, in which the spectral positions of the photonic band gap and the luminescence peak of the quantum dots coincide (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Nanolasers from ZnO nanorods as natural resonance cavities
Authors: Visimberga G. , Yakimov E. E. , Redkin A. N. , Gruzintsev A. N. , Volkov V. T. , Romanov S. , Emelchenko G. A. 
Published: March 2010

AbstractZnO provides conditions for the formation of a variety of micro/nanostructures which act as laser resonators sustaining guided modes, whispering gallery modes, random lasing and a combination of them. The scanning cathodoluminescence spectra and images of a ZnO nanorod with two mirrors at the end faces are studied at 10 K. Emission peaks of bound excitons and edge luminescence are observed in the ultraviolet spectral region. The spatial distribution pattern of emission intensity corresponding to localized photon modes of the nanorod is recorded at different wavelengths. A new method of visualization of localized optical modes in micro‐ and nano‐sized laser cavities is suggested. The lasing peaks display successive onset and saturation with increasing excitation power density, and fit well the expected resonance spectrum of guided modes in hexagonal ZnO nanorods (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Growth conditions and structural properties as limiting factors of electrical parameters of ZnO thin films grown by Atomic Layer Deposition with diethylzinc and water precursors
Authors: Krajewski Tomasz A. , Łuka Grzegorz , Wachnicki Łukasz , Guziewicz Elżbieta , Godlewski Marek , Witkowski Bartłomiej , Łukasiewicz Małgorzata , Łusakowska Elżbieta , Kowalski Bogdan J. , Paszkowicz Wojciech 
Published: March 2010

AbstractThis paper discusses the correlations between growth conditions and electrical, structural and optical properties of zinc oxide thin films grown at low temperature by Atomic Layer Deposition (ALD) method from diethylzinc (DEZn) and deionized water. The surface morphology and microstructure of ZnO layers were studied with Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM) and X‐ray Diffraction (XRD) techniques. The electrical and optical properties of samples were examined by performing room temperature Hall effect and photoluminescence (PL) measurements. These investigations and Electron Dispersive X‐ray (EDX) analysis revealed that changes of the growth conditions (growth temperature, number of ALD cycles (layer thickness)) enable us to control the free electron concentration in as‐grown ZnO layers in the range of 1017 – 5×1019cm–3, which is related to the changes in structural properties and stoichiometry of the films (defect concentration, grains' sizes). (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effects of a high humidity environment and air anneal treatments on the electrical resistivity of transparent conducting ZnO‐based thin films
Authors: Asvarov Abil , Abduev Aslan , Akhmedov Akhmed , Abdullaev Abdulla 
Published: March 2010

AbstractTransparent conducting Al‐doped and Ga‐doped ZnO thin films (so‐called AZO and GZO, respectively) have been grown on glass substrates by dc magnetron sputtering under identical growth conditions. The thermal stability and the damp heat stability of AZO and GZO thin films deposited at room temperature (RT) as well as 250 °C were investigated for hi‐tech applications in thin‐film solar cells and displays. AZO and GZO thin films grown at 250 °C have showed much greater stability to air and damp heat treatments than thin films deposited at RT. At growth temperature of 250 °C, however, it was shown that GZO thin films resistivity to various treatments was significantly more stable than one for AZO thin films. The mechanism of the charge carrier transport in doped ZnO conducting thin films has been proposed. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Photoluminescence studies of HgCdTe epilayers
Authors: Robin I. C. , Taupin M. , Derone R. , Solignac A. , Ballet P. , Lusson A. 
Published: March 2010

AbstractPhotoluminescence spectra on Hg1‐xCdxTe (x∼0.3) layers grown by molecular beam epitaxy on CdZnTe substrates were studied. The investigations were carried out on non intentionally doped, In doped and As doped samples and the effect of different annealing procedures were investigated. Excitation‐power dependent and temperature dependent comparative studies were performed. The transition mechanisms are discussed. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A novel chrysanthemum‐like ZnO nanostructure synthesized by the ultrasonic spray pyrolysis method
Authors: Guo Yun , Wei Xiaoyin , Wang Bin , Zhao Yue , Min Jiahua , Sang Wenbin 
Published: March 2010

AbstractA novel ZnO nanostructure was synthesized by the ultrasonic spray pyrolysis method. X‐ray diffraction (XRD) and Raman Spectroscopy analyses reveal the hexagonal polycrystalline structure of wurtzite. Under the lower magnification image of Scanning Electron Microscopy (SEM), ZnO film exhibits a chrysanthemum‐like configuration. Their petals are built up from numerous fine particles linking together under higher magnifications, with the uniform diameters of 100 nm. The strong peaks for Zn and O in the EDS (Energy Dispersive Spectroscopy) spectrum indicate the main chemical composition. The reasonable growth process and formation mechanism of the unique ZnO nanostructure were proposed (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Transport properties of microstructured MF‐sputtered Zn0.98Al0.02O
Authors: Piechotka M. , Elm M. T. , Henning T. , Szyszka B. , Meyer B. K. , Klar P. J. 
Published: March 2010

AbstractWe studied the effect of microstructuring on the electric transport properties of Zn0.98Al0.02O thin films (AZO) grown by reactive mid‐frequency magnetron sputtering. A series of AZO wire arrays was prepared by photolithography followed by wet‐chemical etching. The nominal wire width b′ was varied between 8 and 32 j.m. The wire arrays were characterized by scanning electron microscopy, atomic force microscopy, and temperature‐dependent resistivity measurements. The extension z of the surface‐layer affected by the microfabrication process and its effect on the electronic transport through the wire were assessed. z is determined by the grain structure of the sputtered layer and is independent of wire thickness and degree of under‐etching (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Seebeck effect of as‐grown and micro‐structured metallic (Zn,Al)O
Authors: Homm G. , Teubert J. , Henning T. , Klar P. J. , Szyszka B. 
Published: March 2010

AbstractWe studied the Seebeck coefficient S of sputtered Zn0.98Al0.02O samples with free carrier concentrations varying from 1018 to 1021 cm–3. The temperature dependence of the Seebeck coefficient at low carrier concentrations exhibits typical semiconductor behavior (S < 0 and pronounced phonon drag below 80K) whereas the metallic as‐grown Zn0.98Al0.02O shows a sign reversal of the Seebeck coefficient with decreasing temperature which is related to the not square‐root‐like density of states of this degenerately doped metallic material. Furthermore, metallic specimens were microstructured by photolithography and wet‐chemical etching with a pattern based on a square grid with a unit cell consisting of a centered square‐hole. The Seebeck coefficient changed systematically with decreasing size of the unit cell. The change of S is caused by a shift of the Fermi energy due to the creation of additional surface traps at the sidewalls of the micro holes (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Hybrid resonant organic‐inorganic nanostructures for novel light emitting devices and solar cells
Authors: Agranovich Vladimir M. , Rupasov Valery I. , Silvestri Leonardo 
Published: March 2010

AbstractThe energy transfer from an inorganic layer to an organic component of resonant hybrid organic/inorganic nanos‐tructures can be used for creation of new type of LED. We mentioned the problem of electrical pumping which has to be solved. As was first suggested in 1979 by Dexter the transfer energy in opposite direction from organic part of nanostructure to semiconductor layer can be used for the creation of new type of solar cells.In this note we stress the importance of the idea by Dexter for photovoltaics and solar cells. We argue that the organic part in such hybrid structures can play a role of an effective organic collector of the light energy (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A new insight on the role of Mg in calcite
Authors: Stashans Arvids , Chamba Gaston 
Published: March 2010

AbstractMagnesium is a key determinant in calcite (CaCO3) mineralization having a notable significance upon the carbonate growth. Magnesium is also present in CaCO3 mineral scale formation which is a persistent and expensive problem in oil and gas production. In the present work, we attempt to treat CaCO3 calcite mineral bulk inducing different concentrations of Mg impurity. The study is done using a quantum‐chemical computer code based on the Hartree–Fock method. It is found that small Mg impurity concentrations produce a significant distortion of the defect‐closest O atoms thus developing local microstructures being distinct to those of the original calcite structure. This structural alteration is accompanied by the electron density redistribution from the O 2pz atomic orbitals (AOs) toward the O 2px and 2py AOs for impurity nearest oxygens. On the other hand, the high Mg impurity concentrations make the chemical bonding in calcite more ionic. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011
Expansion of the π‐molecular orbitals of the C60 fullerene in spherical harmonics
Authors: Nikolaev A. V. 
Published: March 2010

AbstractStarting with the Hückel model for the C60 fullerene, we discuss details of the expansion of the occupied π‐molecular orbitals in terms of spherical harmonics. Our calculation unambiguously indicates that the highest occupied molecular orbital (HOMO, 1hu) and the lowest unoccupied molecular orbital (LUMO, 2t1u) have the largest contribution from the terms with ℓ = 5. This observation justifies the important “ℓ = 5 approximation” for HOMO and LUMO of the C60 fullerene. As a result, the angular dependence of HOMO and LUMO can be written in a simple analytical form. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011
Role of OH bonding in catalytic activity of Nb2O5 during the course of dehydrogenation of MgH2
Authors: Hirate H. , Sawai H. , Yukawa H. , Morinaga M. 
Published: March 2010

AbstractThe hydrogen desorption reaction of MgH2, MgH2 → Mg + H2, is accelerated by the addition of metal oxide catalysts (e.g., Nb2O5). From our theoretical calculation of electronic structure, it was predicted that the catalytic activities of metal oxides are related closely to the OH interaction operating at the interface between oxide catalyst and MgH2. In this study, the OH vibration on the Nb2O5‐catalyzed MgH2 was investigated experimentally using FTIR spectroscopy. The broad absorption band due to the OH stretching mode was observed in the region of 2,800–3,600 cm−1 in the FTIR spectra of the specimens when hydrogen desorption reaction was in progress. The absorbance of the band decreased monotonously with decreasing hydrogen content in the specimen during the course of dehydrogenation of MgH2. This experimental result was in agreement with our prediction for the existence of OH interaction in the hydrogen desorption process. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011
H‐atom acceptor capacity of free radicals used in antioxidant measurements
Authors: Košinová Pavlína , Di Meo Florent , Anouar El Hassane , Duroux Jean‐Luc , Trouillas Patrick 
Published: March 2010

AbstractAntioxidants are well‐known for their beneficial effects on human health. Their capacity to scavenge free radicals mainly depends on their capacity to transfer H atoms to free radicals (R•), and indirectly to labile H‐atoms of the R•‐parent molecule (RH). The aim of this study was to select an accurate method to estimate bond dissociation enthalpies (BDEs) of ROOH, LOOH and DPPHH. ROO• and LOO• are radicals involved in lipid peroxidation and DPPH is a free radical used to measure antioxidant activities. BDE(ROOH) was systematically calculated with more than 20 different methods (HF, post‐HF and DFT). This methodology was performed on three ROOH prototypes (HOOH, CH3OOH, and CH3CH2OOH) for which theoretical BDEs were compared to experimental BDEs. B3P86 and BHandH/6‐31+G(d,p) appeared as the best compromises. The influence of R chain length and conjugation degree on BDEs was studied with DFT. Both parameters did not significantly change BDE(ROOH), except when intra H bonding was formed. The DPPHH BDE was accurately calculated with B3P86. This functional could definitely be considered as a good compromise since it also gave a reliable estimation of OH BDE for polyphenols. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011
Inhibition of Notch Signaling in Human Embryonic Stem Cell–Derived Neural Stem Cells Delays G1/S Phase Transition and Accelerates Neuronal Differentiation In Vitro and In Vivo
Authors: Borghese Lodovica , Dolezalova Dasa , Opitz Thoralf , Haupt Simone , Leinhaas Anke , Steinfarz Barbara , Koch Philipp , Edenhofer Frank , Hampl Ales , Brüstle Oliver 
Published: March 2010

Abstract
The controlled in vitro differentiation of human embryonic stem cells (hESCs) and other pluripotent stem cells provides interesting prospects for generating large numbers of human neurons for a variety of biomedical applications. A major bottleneck associated with this approach is the long time required for hESC-derived neural cells to give rise to mature neuronal progeny. In the developing vertebrate nervous system, Notch signaling represents a key regulator of neural stem cell (NSC) maintenance. Here, we set out to explore whether this signaling pathway can be exploited to modulate the differentiation of hESC-derived NSCs (hESNSCs). We assessed the expression of Notch pathway components in hESNSCs and demonstrate that Notch signaling is active under self-renewing culture conditions. Inhibition of Notch activity by the γ-secretase inhibitor N-[N-(3,5-difluorophenacetyl)-L-alanyl]-S-phenylglycine t-butyl ester (DAPT) in hESNSCs affects the expression of human homologues of known targets of Notch and of several cell cycle regulators. Furthermore, DAPT-mediated Notch inhibition delays G1/S-phase transition and commits hESNSCs to neurogenesis. Combined with growth factor withdrawal, inhibition of Notch signaling results in a marked acceleration of differentiation, thereby shortening the time required for the generation of electrophysiologically active hESNSC-derived neurons. This effect can be exploited for neural cell transplantation, where transient Notch inhibition before grafting suffices to promote the onset of neuronal differentiation of hESNSCs in the host tissue. Thus, interference with Notch signaling provides a tool for controlling human NSC differentiation both in vitro and in vivo.
Epidemiology of Small Bowel Carcinoids in a Defined Population
Authors: Landerholm Kalle , Falkmer Sture , Järhult Johannes 
Published: March 2010

AbstractBackgroundThis retrospective study describes the epidemiology of small bowel carcinoids in a geographically defined population, with no other selection bias.MethodsAll patients (n = 145) resident in Jönköping County when diagnosed with carcinoid in the jejunum or ileum from 1960 to 2005 were included. Medical records were reviewed in detail, and tumor specimens were histopathologically and immunohistochemically reexamined when required (n = 44).ResultsThe annual age‐adjusted incidence of small bowel carcinoids was 1.12 (95% confidence interval 0.95–1.31) per 100,000 persons. Median age at diagnosis was 69 years. The predominating presenting symptom was uncharacteristic abdominal pain (50%), whereas a smaller number suffered from typical flushes (13%). Surprisingly, 14% presented with overt gastrointestinal hemorrhage. Most of the patients diagnosed based on their symptoms had metastases at diagnosis (44% regional, 40% distant). Metastasized tumors by definition belong to World Health Organization (WHO) histopathologic group 2; and when reexamined, most (83%) of the localized tumors were also found to belong to WHO group 2.ConclusionsIn comparison to previous reports, a higher age‐adjusted incidence of small bowel carcinoids was observed, and the patients were clearly older at the time of diagnosis. Even with metastatic disease, the presenting symptoms were usually uncharacteristic, and the carcinoid syndrome was infrequently seen.
Synthesis of High Purity Mono‐Alkyl Phosphate Using Cyclic Polyphosphoric Acid
Authors: Ye Qingguo , Yan Shuyun 
Published: March 2010

AbstractThe uniform design method was used to study the synthesis of high purity mono‐alkyl phosphate (MAP) by cyclic polyphosphoric acid. The main factors influencing the content of mono‐alkyl phosphate were investigated. The experimental results were analyzed by regression, and the optimum conditions were found to be as follows: mass pentoxide/mass 85 wt% phosphoric acid/mass octanol = 14.2/5.62/48.5, reaction temperature: 115°C, reaction time: 8 h. Under the optimized conditions, a high purity mono‐alkyl phosphate with 98.6 wt% MAP yield was obtained.
The Conversion of Low Grade Tallow into Biodiesel‐Grade Methyl Ester
Authors: Fröhlich András , Rice Bernard , Vicente Gemma 
Published: March 2010

AbstractThe conversion of low grade tallow with free fatty acid contents of 11.0–26.0% into biodiesel‐grade methyl ester was investigated on a laboratory scale. Methanolysis of low grade tallow could not be carried out by the standard base‐catalysed process, because the high free fatty acid content of low grade tallow caused incomplete methanolysis and prevented phase separation. The problem was able to be partly overcome by adding more potassium hydroxide to neutralise the free fatty acids, 50–100% more methanol and some water to promote phase separation. However, even with the modified method only about 55% of the starting material could be recovered as methyl ester and this fell to 35 and 14% when the free fatty acid content of tallow increased to 20 and 26%, respectively. It was shown that yield losses were caused mainly by the dissolution of methyl ester in the glycerol phase, and to a lesser extent to hydrolysis of the triglycerides. In order to prevent yield losses caused by the dissolution of methyl ester in the glycerol phase the possibility of esterifying free fatty acids either before or after base catalysed methanolysis was investigated. Both methods involving methanolysis and esterification gave good conversions of low grade tallow to methyl ester, and in each case yields above 90% were obtained by relatively simple processes.
Activity rating of Pliocene–Quaternary faults: a formalized approach (example of the Baikal rift system)
Authors: Lunina O.V. 
Published: March 2010

Abstract
It is suggested to estimate the Pliocene–Quaternary fault activity in a formalized way from synthesis of different data. The respective database consists of two main sections: (i) general information and basic fault parameters and (ii) geomorphic, structural, paleoseismic, seismological, geophysical, geodetic, engineering-geological, hydrological, and meteorological data. The fault characteristics are scored according to their significance, and the cumulative score measures the fault activity. With this approach, the faults in the Barguzin and Tunka rift basins and in the northeastern flank of the Baikal rift system have been divided into five activity classes (low, medium, relatively high, high, and very high activity) and mapped correspondingly. It has been recommended that the concept of an hazardous fault, as updated with regard to the activity rating, refers to faults of relatively high, high, and very high activity. Thus identified hazardous faults within the study area are quite few (4–8%), though this percent may increase slightly as more input data become available. The underestimation cannot be dramatic because all known seismological and structural characteristics of faults essential for the activity rating have been already taken into account. The new approach may be useful in seismic risk assessment and in choice of sites for instrumental monitoring of seismicity.