bluuebunny/crossref_metadata_2025_split huggingface dataset:
Computational homogenization for heat conduction in heterogeneous solids
Authors: Özdemir I. , Brekelmans W. A. M. , Geers M. G. D. 
Published: May 2007

AbstractIn this paper, a multi‐scale analysis method for heat transfer in heterogeneous solids is presented. The principles of the method rely on a two‐scale computational homogenization approach which is applied successfully for the stress analysis of multi‐phase solids under purely mechanical loading. The present paper extends this methodology to heat conduction problems. The flexibility of the method permits one to take into account local microstructural heterogeneities and thermal anisotropy, including non‐linearities which might arise at some stage of the thermal loading history. The resulting complex microstructural response is transferred back to the macro level in a consistent manner. A proper macro to micro transition is established in terms of the applied boundary conditions and likewise a micro to macro transition is formulated in the form of consistent averaging relations. Imposition of boundary conditions and extraction of macroscopic quantities are elaborated in detail. A nested finite element solution procedure is outlined, and the effectiveness of the approach is demonstrated by some illustrative example problems. Copyright © 2007 John Wiley & Sons, Ltd.
Role of APAF‐1, E‐cadherin and peritumoural lymphocytic infiltration in tumour budding in colorectal cancer
Authors: Zlobec I , Lugli A , Baker K , Roth S , Minoo P , Hayashi S , Terracciano L , Jass J R 
Published: May 2007

AbstractTumour budding or dedifferentiation at the invasive margin of colorectal cancer (CRC) is an important prognostic marker and linked mechanistically to dysregulation of Wnt pathway signalling. Since budding is observed in only 40% of CRCs, we hypothesized that Wnt pathway dysregulation may be a necessary but insufficient explanation for budding and that buds may be destroyed selectively by tumour immune mechanisms. Twenty potential markers of tumour budding were evaluated in tissue microarrays (TMAs) obtained from the main tumour body of 1164 DNA mismatch repair‐proficient CRCs and the findings were correlated with tumour budding, lymphocytic infiltration and survival. Loss of expression of E‐cadherin and APAF‐1 were independent predictors of budding (sensitivity 70.3% and specificity 48.2% when one or the other was lost). Peritumoural lymphocytes (PTLs) were observed more frequently in CRCs with loss of either E‐cadherin or APAF‐1 that were budding‐negative. PTLs and tumour‐infiltrating lymphocytes (TILs) were strongly correlated. The absence of TILs increased the adverse prognostic impact of E‐cadherin and APAF‐1 loss. Co‐occurrence of E‐cadherin loss, APAF‐1 loss and low TIL counts in CRCs was an independent prognostic factor. The findings were verified in whole tissue sections from 88 CRCs with known KRAS mutation status (which was not associated with budding). Loss of E‐cadherin and APAF‐1 within the main body of CRCs are independent predictors of tumour budding. The prognostic benefit of lymphocytic infiltration may be explained by the immune destruction of budding cells. Copyright © 2007 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Defect structure of ZrO2‐doped rare earth perovskite scintillators
Authors: Stanek C. R. , Levy M. R. , McClellan K. J. , Uberuaga B. P. , Grimes R. W. 
Published: May 2007

AbstractDuring the systematic consideration of 4+ cation doping of REAlO3 perovskites for 4+ cations ranging from Ti4+ to Pb4+, a normalization error was discovered in the original Zr4+ solution data that appears in C. R. Stanek et al., phys. stat. sol. (b) 242, R113 (2005). The corrected figure describing solution energetics of Zr4+ in REAlO3 perovskites is provided. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Magnetic ordering of Mn and Ru in (La0.52Ba0.48) (Mn0.51Ru0.49)O3
Authors: Wu S. Y. , Li W.‐H. , Yang C. C. , Lynn J. W. , Liu R. S. 
Published: May 2007

AbstractThe cover picture of the current issue relates to the article by S. Y. Wu et al. [1]. The authors study the crystal structure and magnetic properties of a polycrystalline (La0.52Ba0.48) (Mn0.51Ru0.49)O3 sample. The critical temperatures of Ru and Mn were determined using the temperature dependent peak intensities. Neutron magnetic diffraction measurements show anomalies that are associated with the ferromagnetic ordering of the Mn and Mn/Ru spins, respectively, with the spin magnetic moments (shown as arrows) either parallel or at an inclined angle to the c‐axis direction.The corresponding author Sheng Yun Wu is Assistant Professor at the Department of Physics of the National Dong Hwa University in Hualien, Taiwan. His research interests include the study of magnetic properties in perovskite system and spin polarization of closed d‐shell nanoparticles.
Capture kinetics at deep‐level electron traps in GaN‐based laser diode
Authors: Yastrubchak O. , Wosiński T. , Mąkosa A. , Figielski T. , Porowski S. , Grzegory I. , Czernecki R. , Perlin P. 
Published: May 2007

AbstractTwo deep‐level electron traps, E1 at EC – 0.23 eV and E2 at EC – 0.55 eV, have been revealed by means of deep‐level transient spectroscopy (DLTS) in a GaN‐based laser‐diode heterostructure grown by metalorganic vapour‐phase epitaxy on a bulk GaN substrate. The two traps represent different electron capture behaviours. The E1 trap, which exhibits the logarithmic capture kinetics and the DLTS‐line shape characteristic of band‐like electron states, is attributed to the core states of threading dislocations in a p ‐type layer of the structure. In contrast, the E2 trap, being the most prominent deep‐level electron trap in GaN layers, displays the exponential capture kinetics and is assigned to isolated point defects, likely the nitrogen antisite defect. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Theory of partial dislocations in SiC
Authors: Savini G. 
Published: May 2007

AbstractSiC p‐i‐n diodes exhibit an increase in the voltage drop under forward bias which has been linked with the increased mobility of the partial dislocations. Through first‐principles calculations I have investigated the Shockley partials in 4H‐SiC. I have found that the asymmetric reconstructions do not posses midgap states, while the symmetric reconstructions are always electrically active with a half‐filled band. The kink migration analysis have demonstrated that the symmetric reconstructions are always more likely to migrate. Further I have proposed a new theoretical model that can explain the enhancement of the dislocation mobility under forward bias. This model can be applied to any semiconductor materials in order to predict the behaviour under electron‐hole plasma injections. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Studies on dislocation patterning in 6‐inch GaAs crystals
Authors: Rudolph P. , Frank‐Rotsch Ch. , Juda U. , Eichler St. , Scheffer‐Czygan M. 
Published: May 2007

AbstractThe present paper investigates the correlations between the cell dimension d of characteristic dislocation cell patterns and acting thermo‐elastic stress τ at the growth of 6‐inch semi‐insulating VCz and VGF GaAs crystals. Whereas the dislocation density and cells are analysed experimentally the history of the elastic stress, responsible for the cell formation, is obtained by global numeric calculation. At stresses below 1 MPa diffusion‐controlled creep is the dominant mechanism of dislocation motion. Different d (τ) ‐ proportionalities in VCz and VGF crystals are determined. This is due to the varying thermal conditions and stay times of the growing crystal at high temperatures. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Role of extended defects in brown colouration of diamond
Authors: Hounsome L. S. , Jones R. , Martineau P. M. , Fisher D. , Shaw M. J. , Briddon P. R. , Öberg S. 
Published: May 2007

AbstractThe absorption spectrum of brown diamond is broad and featureless, in both natural type IIa and CVD‐grown material. It is argued that such an absorption is due to an extended, rather than a point, defect. Ab‐initio modelling studies have been conducted on dislocations and extended vacancy‐related defects. While certain dislocations could potentially explain the origin of colour, their density is too low to account for experimentally observed absorption magnitudes. It is demonstrated that a vacancy disk lying in the {111} plane has an absorption spectrum similar to that seen in natural and CVD brown diamond. Such disks are unstable above about 200 vacancies and should relax to dislocation loops in natural diamond. Hydrogen is shown to passivate the optical activity of the disks. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The role of dislocations in producing efficient near‐bandgap luminescence from silicon
Authors: Fraser K. , Stowe D. , Galloway S. , Senkader S. , Falster R. , Wilshaw P. 
Published: May 2007

AbstractCathodoluminescence is used to investigate the phenomenon of relatively efficient band‐to‐band luminescence from silicon specimens processed to contain near surface dislocations. Dislocations are produced either by ion implantation and subsequent high‐temperature annealing or by mechanical abrasion of specimens having a wide range of doping concentrations. It is found that the luminescence is not directly related to the presence of dislocations and, in some cases, can be enhanced by low temperature annealing. This luminescence behaviour is explained by the effect of competing non‐radiative recombination due to impurity deep levels and Auger recombination. The enhancement observed in some specimens is due to gettering of the deep level impurities. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Nanoindentation response of compound semiconductors
Authors: Le Bourhis E. , Patriarche G. 
Published: May 2007

AbstractThe paper reviews the nanoindentation behaviour of III‐V semiconductors under concentrated load and its implication for optoelectronic‐device design. We consider first, fundamental aspects involved into the mechanical resistance to contact loading of semiconductor single crystals (elastic‐plastic transition, indentation strain, hardness‐yield relationship). The paper then describes recent applicative studies aimed at improving the heterostructure quality used in optoelectronic applications and emphasizes the so‐called mechanical design (alloying and compliant substructure). (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Luminescence of dislocation network in directly bonded silicon wafers
Authors: Yu X. , Kittler M. , Vyvenko O. F. , Seifert W. , Arguirov T. , Wilhelm T. , Reich M. 
Published: May 2007

AbstractThe luminescence behaviors of dislocation network in directly bonded silicon wafers have been investigated in this paper. The individual dislocations were observed in the sample bonded with extreme small misorientation angles by electron beam induced current (EBIC) technique. The temperature dependence of EBIC contrast of the dislocation lines showed that its contamination degree was smaller than 104/cm. The cathodoluminescence (CL) from the dislocation networks showed D1‐line existed in all the bonded samples, often along with D2‐line. The D3/D4‐lines could also be obtained by tuning the misorientations. Meanwhile, the application of an external bias can effectively enhance the luminescence. Furthermore, a metal‐insulator (SiOx, x < 2)‐semiconductor light‐emitting diode (MOS‐LED) based on the bonded silicon wafer was demonstrated. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effects of two‐step rapid thermal processing in different ambients on denuded zone and oxygen precipitation in Czochralski silicon
Authors: Fu Liming , Yang Deren , Ma Xiangyang , Cui Can , Que an. Duanlin 
Published: May 2007

AbstractThe effects of two‐step rapid thermal processing (RTP) sequentially in different ambients on the formation of denuded zone (DZ) and oxygen precipitation in the Czochralski (CZ) silicon wafers have been investigated. With the first‐step RTP in Ar ambient, no obvious DZ but a high density of bulk micro‐defects (BMDs) were formed in the sample with the second‐step RTP in N2 ambient, while the BMD density in the sample with the second‐step RTP in O2 ambient was remarkably low. With the first‐step RTP in N2 ambient, a high density of BMDs and a width of DZ could be formed in either of the samples with the second‐step RTP in Ar or O2 ambient, but the DZ width in the two samples differed to a certain extent. With the first‐step RTP in O2 ambient, the two samples with the second‐step RTP in Ar and N2 ambients respectively possessed reasonably comparable DZ width and BMD density. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Structure and energy of partial dislocations in wurtzite‐GaN
Authors: Savini G. , Blumenau A. T. , Heggie M. I. , Öberg S. 
Published: May 2007

AbstractFirst‐principle calculations have shown that both the partials can be electrically active. In particular we have shown the Ga(g) core partials are a good candidate for the observed absorption peak at 2.4 eV revealed by energy loss spectroscopy measurements. The symmetric and asymmetric reconstructions have relatively close formation energies. Our results have suggested that the asymmetric reconstructions, characterized by strong bonds along the dislocation line are favourable in intrinsic materials. However, in strongly p and n‐type materials or in high stress field the symmetric reconstructions can become energetically more stable. These reconstructions are always electrically active with a deep band across the forbidden gap. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Peculiarities of dislocation photoluminescence in germanium with quasi‐equilibrium dislocation structure
Authors: Shevchenko S. , Tereshchenko A. 
Published: May 2007

AbstractThe dislocation photoluminescence (DPL) at 4.2 K was studied in germanium (Ge) single crystals of n‐ and p‐type with quasi‐equilibrium structure of 60° dislocations. The DPL spectra for different samples were decomposed on Gaussian lines (Gm‐lines) over the range 0.47‐0.58 eV characterized by practically the same peak energies Em and the widths under 15 meV. The G‐lines with Em ≤ 0.55 eV were ascribed to the radiation of regular segments of 60° dislocations with different stacking fault (SF) widths Δ between 30 and 90° partials. An increase of the dislocations density up to ND ∼ 107 cm–2 was found to result in a considerable growth of the intensity of the G‐lines with Em <0.513 eV. The factors, which promote the appearance of different Δ values for quasi‐equilibrium 60° dislocation structure, are discussed. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
X‐ray diffuse scattering from carbon‐ion‐irradiated diamond
Authors: Sugai H. , Maeta H. , Matsumoto N. , Kato T. , Haruna K. , Sataka M. , Ono F. 
Published: May 2007

AbstractSynthetic single crystal diamonds are irradiated with 100 MeV carbon‐ion and characterized by measurements of the X‐ray lattice parameter and diffuse scattering (XDS) at room temperature. The lattice parameter increases with the ion fluence. The intensity of XDS diffuses asymmetrically to form a streak along the [‐1 0 0] direction parallel to the reciprocal lattice vector. These results suggest that interstitial atoms induced by irradiation aggregate to form dislocation loop on the (1 0 0) plane in the synthetic single crystal diamonds. The results are similar to the XDS of boron‐doped single crystal diamond suggesting that boron atoms are likely to form precipitates on the (1 0 0) plane. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Bound electronic states on a dislocation kink in semiconductors
Authors: Vardanyan Robert A. , Kteyan Armen A. 
Published: May 2007

AbstractWe discuss electron localization on dislocation kinks, that is essential for multiphonon capture of carriers by the dislocation, in view of the problem of recombination‐enhanced defect glide in wide‐band semiconductors. In the case of a smooth kink (when the continuum model is applicable) the formation of bound electronic states is analyzed analytically. The eigenstates and corresponding wave functions are found, depending both on kink parameters and electronic characteristics of the semiconductor. A possible application of the obtained results for the analysis of electron localization on an abrupt kink is considered. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Defect structure in self‐implanted silicon annealed under enhanced hydrostatic pressure – electron microscopy study
Authors: Wzorek M. , Czerwinski A. , Ratajczak J. , Misiuk A. , Surma B. , Kątcki J. 
Published: May 2007

AbstractThe effect of hydrostatic pressure on crystal structure of annealed self‐implanted silicon was investigated by transmission electron microscopy and scanning electron microscopy observation of selectively etched samples. 3°‐angle bevel mechanical polishing allowed determining depth distributions of dislocations. The effect of enhanced hydrostatic pressure on recrystallization and dislocation evolution depending on annealing temperature was discussed. The structure of defects in annealed samples was correlated with photoluminescence spectra on the basis of transmission electron microscopy analysis. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A new method of strain determination in partially relaxed thin films
Authors: Maciejewski G. , Sarzyński M. , Domagala J. Z. , Leszczyński M. 
Published: May 2007

AbstractIt is well known that classical Stoney's formula for radius of thin film bowing fails when thin film is dislocated. Thereby, a method of determination lattice parameters for each of heterostructure epilayers is needed when inelastic relaxation takes place. In this article, we have developed a method of determination lattice parameters of a heterostructure from radius curvature measurement data. Description of deformation when dislocations are nucleated is carefully analyzed. It is shown that in order to take into account nucleated dislocations in thin film an additional term responsible for increased volume of layers should be included in the analysis. The proposed method is based on the finite deformation elasticity and uses the finite element method and bowing radius measurement by the laser beam reflection method. As an example the nitride alloy heterostructure with GaN as a substrate is analyzed. The verification is performed using X‐ray measurement of lattice parameters. A very good correspondence between numerically determined lattice parameters and XRD measurements data are observed. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Stress and unemployment
Authors: Fagin Leonard 
Published: May 2007

AbstractAlthough not a new phenomenon, unemployment is now a feature of most industrialized societies. Previous research has highlighted the nature of physical and psychological problems associated with this major life event. Before describing the nature of the response to unemployment, it is essential to analyse why work has become so important for social and psychological adjustment. The response to unemployment can then be described as a predictable set of phases similar to other experiences of loss, such as bereavement. Pathology in unemployment, both physical and psychological, has been observed, and the nature of these disorders is described, as well as those groups more likely to suffer and the possible pathways from health to illness.
Of man and pigs: Is malignant hyperthermia a stress‐related disorder?
Authors: Hall G. M. , Lucke J. N. 
Published: May 2007

AbstractMalignant hyperthermia (MH) is a very rare but frequently fatal complication of anaesthesia. The identification of susceptible patients depends on a family history of anaesthetic difficulties, increased serum creatine kinase activity and the pharmacological assessment of a muscle biopsy. Dantrolene has been introduced recently as a specific therapeutic agent for MH. Detailed investigation of MH in pigs has drawn attention to the possible role of circulating catecholamines in initiating and potentiating the syndrome. Only certain breeds of pigs develop MH and these breeds are also susceptible to the occurrence of the porcine stress syndrome (PSS) and pale, soft, exudative pork (PSEP). There is increasing evidence that isolated cases of ‘awake MH’ can be triggered by excessive fatigue, emotional stress and high environmental temperatures. It is possible that in some MH‐susceptible families death may occur from ventricular arrhythmias in emotional stressful situations, possibly associated with an underlying cardiomyopathy.
Psychiatric aspects of violence in Northern Ireland
Authors: Cairns Ed , Wilson Ronnie 
Published: May 2007

AbstractThis article reviews a number of studies which have examined the possible impact of political violence on psychiatric morbidity in Northern Ireland. A brief introduction outlining the way in which the violence has varied spatially, quantitatively and qualitatively since 1969 also draws attention to other possible stressors in Northern Irish society. This is followed by a detailed review of studies which have analysed either admission and referral rates, suicide and attempted suicide rates, trends in psychotropic drug prescribing or data from community‐based studies. The criticism is made that several of the early studies did not pay enough attention to important sociodemographic factors and therefore are open to interpretations other than those originally proposed. Nevertheless some agreement does emerge suggesting that it is unlikely that the political violence caused any marked increase in serious psychiatric illnesses but rather stimulated an increase in normal anxiety, particularly among the more vulnerable and especially those with a previous history. Further recent research has begun to suggest that denial of the seriousness of the violence may be one of the mechanisms being used to enable people in Northern Ireland to cope with this continuing problem.
The relationship of hypertension and its treatment with stress and well‐being
Authors: Gill J. S. , Beevers D. G. 
Published: May 2007

AbstractThe evidence that environmental stress or personality type are related to hypertension is inconsistent. A review of the literature reveals that a multitude of stressors has been investigated in relation to hypertension and interest in the treatment of hypertension by non‐pharmacological methods, including stress management, has increased. Well‐being has been defined as the ability to perform a normal occupation, housework, hobbies and leisure interests, and this also includes enjoyment of eating, drinking, personal relations, social contacts and sex. There is little evidence that the state of well‐being differs between individuals unaware of their hypertensive status and normotensives, although there does appear to be an influence of labelling individuals as hypertensives on the well‐being status. The act of diagnosis and drug treatment may impair well‐being and it is important that clinicians appreciate the negative effects of therapy as well as the benefits.
Possible protective value of severe psychopathology against lethal effects of an unfavourable milieu
Authors: Randrup Axel 
Published: May 2007

AbstractVoles were studied in restricted and enriched milieux and observations made of stereotypy and social hierarchy. Further experiments compared the behaviour of voles caught in the wild to that of voles reared in the laboratory. Tyrannic hierarchy was observed in 77 per cent of cages with a restricted environment as compared to 10 per cent of those with an enriched environment (p< 0.005). The incidence of stereotyped and hyperaggressive behaviour was significantly greater in laboratory bred animals and excessive water‐drinking and death significantly greater in the wild species.