bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tetrahedral germanium in amorphous phase change materials: Exploring the isochemical scenario
Authors: Micoulaut Matthieu , Kachmar Ali , Charpentier Thibault 
Published: August 2012

AbstractThe structural, vibrational, and electronic properties of low‐temperature supercooled GeTe4 are studied using density functional theory (DFT). Two models have been considered: an ordinary melt‐quenched system containing a majority of defect‐octahedral germanium atoms, and a relaxed one obtained from a quenched SiTe4 rescaled structure which contains mostly tetrahedral germanium, while leaving the Te environment preserved. The tetrahedral system exhibits an increased agreement with the experimental structure factor S(k), the pair distribution function g(r), and the infrared absorption spectrum. It is suggested that the fraction of tetrahedral Ge must be higher as usually believed. In addition, we provide the calculation of the 125Te wideline NMR spectra. While the latter do not agree with recent experimental findings, both systems exhibit important significant differences in the widths of the computed spectra. These exploratory calculations clearly show that NMR will be an interesting probe that deserves further investigations for the experimental determination of the local geometry.
Electronic structure, phonon spectra, and anisotropy of electron–phonon interaction in scandium
Authors: Sichkar S. M. , Antonov V. N. 
Published: August 2012

AbstractThe anisotropy of transport function, electronic structure, Fermi surface, phonon spectra, electron–phonon spectral function, orbital dependence of the cyclotron masses, and extremal cross sections of the Fermi surface of Sc were investigated from first principles using the full potential linear muffin‐tin orbital method. The calculations of the dynamic matrix were carried out within the framework of the linear response theory. A good agreement with experimental data of phonon spectra, electrical resistivity, cyclotron masses, and extremal cross sections of the Fermi surface in high symmetry directions was achieved.
Dual‐Responsive Breakdown of Nanostructures with High Doxorubicin Payload for Apoptotic Anticancer Therapy
Authors: Yoon Sujin , Kim Woo Jin , Yoo Hyuk Sang 
Published: August 2012

AbstractSelf‐assembled nanoaggregates co‐encapsulating doxorubicin (DOX) and oligonucleotide are prepared for dual‐responsive breakdown of the nanostructure with complete disappearance characteristics. Four‐arm poly(ethylene glycol) is co‐conjugated with DOX and anti‐bcl‐2 oligonucleotide with reducible linkers and acid‐cleavable linkers, respectively. The conjugate is hydrophobically self‐assembled into nanoaggregates in aqueous solution. Elemental scanning of the nanoaggregates reveals their core–shell structure with DOX and oligonucleotide located at the core and the shell, respectively. The tracking of size modulation suggests the complete disappearance of the particles under reducing conditions and the liberation of oligonucleotide at low pH, which is confirmed by dynamic light scattering and electron microscopy. The release of DOX and oligonucleotide is controlled by the pH and the reducing potential of the medium, and most of the drug and DNA are released in 24 h. The released fractions are analyzed by reversed‐phase chromatography, which indicates facile cleavage of DOX and oligonucleotide from the carriers. The nanoaggregates with both DOX and oligonucleotide show the lowest IC50 value when a cytotoxicity assay is performed against A549 cells. Apoptosis assay also confirms that cells treated with the nanoaggregates having both DOX and oligonucleotide show higher fluorescence intensity of antiapoptotic antibody than native DOX.
Achieving Ultrahigh Concentrations of Fluorescent Single‐Walled Carbon Nanotubes Using Small‐Molecule Viscosity Modifiers
Authors: Leeds Jarrett D. , Fourkas John T. , Wang YuHuang 
Published: August 2012

AbstractSurfactant dispersion is a well‐established method for stabilizing individual single‐walled carbon nanotubes in aqueous solutions. However, achieving high concentrations of individually dispersed nanotubes with this technique has proven challenging. Here it is demonstrated that the introduction of viscosity‐enhancing compounds such as sucrose can increase the maximum concentration of surfactant‐dispersed single‐walled carbon nanotubes by more than a factor of 100 while still retaining the optical properties of individual nanotubes. When these solutions are used as inks for methods such as inkjet printing, they retain their fluorescent properties even after the ink has dried.
How Can We Better Understand Current and Future Workforce Values in the Global Business Environment?
Authors: Richards Malika , Egri Carolyn P. , Ralston David A. , Naoumova Irina , Casado Tania , Wangenheim Florian v. , Hung Vu Thanh , Pekerti Andre A. , Schroll‐Machl Sylvia 
Published: August 2012

AbstractOur study tested the predictive power of socioeconomic development theory and age differences theory to explain work values across cultures and across age groups. We compared the values orientations of future managers, business students under the age of 25, with those of current managers and professionals, who we split into three decade groups (30 to 39, 40 to 49, and 50 to 59). Our respondents (n = 1,518) come from six diverse societies: Brazil, Germany, Indonesia, Russia, the United States, and Vietnam. Our findings indicate that both theories contribute to our understanding of work values and behaviors. One implication is that while socioeconomic development theory makes an important contribution, it is clearly not sufficient by itself to explain work values/behavior differences in the global context. The study findings and the discussion of them will hopefully provide multinational managers with a clearer assessment of current and future workforce values/behavior. © 2012 Wiley Periodicals, Inc.
Performance Implications of MNEs' Diversification Strategies and Institutional Distance
Authors: Chao Mike Chen‐Ho , Kim Seung H. , Zhao Hongxin , Hsu Chin‐Chun 
Published: August 2012

AbstractBy proposing a conceptual outline for a general model that explains the link between multinational enterprises' (MNEs') diversification and their performance, this study tests the moderating effects of institutional distance empirically. Integrating literature from a strategic perspective within international business research, the proposed integrated, multidimensional framework can analyze MNEs' product diversification, international diversification, and institutional distance, as well as the impacts of these elements on firm performance. A sample of Fortune Global 500 companies confirms this moderation and extends prior research by establishing the importance of relationships among MNEs' product and international diversification, institutional distance, and performance. © 2012 Wiley Periodicals, Inc.
Reflections on the Evolving Terrorist Threat to Luxury Hotels: A Case Study on Marriott International
Authors: Wernick David A. , Von Glinow Mary Ann 
Published: August 2012

AbstractThe advent of global terrorist networks represents a challenge to international business (IB) theory. Traditionally conceptualized as a type of political risk experienced by multinational enterprises (MNEs) operating in conflictive areas, terrorism has evolved in recent years. The global terrorist networks that dominate the international scene today have different motivations, strategies, tactics, and organizational structures than their secular and ethnic‐separatist predecessors and these differences matter for IB theory and practice. Moreover, these groups have shown themselves adaptive, resilient, and capable of striking targets of strategic and symbolic importance in global business and financial centers. This paper examines the changing nature of the terrorist threat to MNEs and the implications for a sector that has been a target of recent attacks: the luxury hotel industry. Structured as a case study of Marriott International, a leading global hospitality provider, the paper analyzes ways the firm is adapting to the evolving threat and the measures it has introduced to safeguard guests, staff, property, and brand. Implications for IB theory and practice are drawn. © 2012 Wiley Periodicals, Inc.
In situ labeling and imaging of endogenous neural stem cell proliferation and migration
Authors: Vande Velde Greetje , Couillard‐Després Sébastien , Aigner Ludwig , Himmelreich Uwe , van der Linden Annemie 
Published: August 2012

AbstractEndogenous neural stem cells (eNSCs) reside in defined regions of the adult brain and have the potential to generate new brain cells, including neurons. Stimulation of adult neurogenesis presents an enormous potential for regenerative therapies in the central nervous system. However, the methods used to monitor the proliferation, migration, differentiation, and functional integration of eNSCs and their progeny are often invasive and limited in studying dynamic processes. To overcome this limitation, novel techniques and contrast mechanisms for in vivo imaging of neurogenesis have recently been developed and successfully applied. In vivo labeling of endogenous neuronal progenitor cells in situ with contrast agents or tracers enables longitudinal visualization of their proliferation and/or migration. Labeling of these cells with magnetic nanoparticles has proven to be very useful for tracking neuroblast migration with MRI. Alternatively, genetic labeling using reporter gene technology has been demonstrated for optical and MR imaging, leading to the development of powerful tools for in vivo optical imaging of neurogenesis. More recently, the iron storage protein ferritin has been used as an endogenously produced MRI contrast agent to monitor neuroblast migration. The use of specific promoters for neuronal progenitor cell imaging increases the specificity for visualizing neurogenesis. Further improvements of detection sensitivity and neurogenesis‐specific contrast are nevertheless required for each of these imaging techniques to further improve the already high utility of this toolbox for preclinical neurogenesis research. WIREs Nanomed Nanobiotechnol 2012, 4:663–679. doi: 10.1002/wnan.1192This article is categorized under:

Diagnostic Tools > In Vivo Nanodiagnostics and Imaging
Therapeutic Approaches and Drug Discovery > Nanomedicine for Neurological Disease
Syntheses, Structures, Magnetic Properties, and NIR Emission Properties of a Series of Novel 1, 2, 4, 5‐Cyclohexanetetracarboxylate‐bridged Lanthanide Complexes with 3D Framework Structures
Authors: Wang Li , Gu Wen , Liao Sheng‐Yun , Zhang Ming , Yang Lin‐Yan , Wei Xiao‐Hua , Liu Xin 
Published: August 2012

AbstractSolvothermal combination of trivalent lanthanide metal precursors with 1, 2, 4, 5‐cyclohexanetetracarboxylic acid (L) ligand has afforded the preparation of a family of eight new coordination polymers [Ln4(L)3(H2O)10]·7H2O (Ln = Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb) (1–8). Structural analyses reveal that the 1, 2, 4, 5‐cyclohexanetetracarboxylic acid ligand with e,a,a,e (LI) conformation displays a μ4‐(κ3O, O, O5)(κ2O2,O2)(κ2O4,O4)‐bridging mode to generate 3D frameworks of complexes 1–8 and the α‐Po topology with the short Schläfli symbol {412.63} could be observed in complexes 1–8. The near‐infrared luminescence properties were studied, and the results have shown that the HoIII, ErIII, and YbIII complexes emit typical near‐infrared luminescence in the solid‐state. Variable‐temperature magnetic susceptibility measurements of complexes 2–7 have shown that complex 2 (Gd) shows the ferromagnetic coupling between magnetic centers, whereas the complexes 3–7 show the antiferromagnetic coupling between magnetic centers. Additionally, the thermogravimetric analyses were discussed.
Formation of Thiosemicarbazone‐Functionalized Complexes with (GeS2)2 and (SnS2)2 Units
Authors: Eußner Jens P. , Dehnen Stefanie 
Published: August 2012

AbstractBy reaction of organo‐functionalized germanium or tin sesquisulfides [(R1T)4S6] (T = Ge, Sn; R1 = CMe2CH2COMe) with thiosemicarbazide or its methyl or phenyl derivative, a series of four compounds were obtained and structurally characterized that are based on an inorganic (TS2)2 unit with an extended organic chelate ligand CMe2CH2CMeNNCSNHR′ (R′ = H, Me, Ph). The products combine a small, reactive metal chalcogenide moiety with a ligand system that allows for a variety of directed extensions at the terminal NHR′ group. Thus, this work represents the starting point to a multifaceted consecutive chemistry involving both the extension of the binary inorganic unit and further derivatization and/or coordination of the organic ligands.
Structural Effects on the Electronic Properties of TlCu7–δS4 Investigated by Diffraction‐Resistance Measurements
Authors: Engin T. Erinc , Hull Steve , Powell Anthony V. 
Published: August 2012

AbstractThe design and construction of a specialised sample cell for the simultaneous investigation of electron‐transport and structural properties by powder neutron diffraction in the temperature range1.5 ≤ T /K ≤ 300 is described. This cell has been used to investigate the structural origin of anomalies in the transport properties of the pseudo‐one‐dimensional ternary sulfide TlCu7–δS4 (δ = 0.15). The data reveal an anomaly in ρ(T) observed at 255 K, which is associated with a phase change involving a change in symmetry from I4/m to P4/n on cooling. This corresponds to a doubling of the crystallographic c axis and is evidenced by the splitting of a strong reflection at d = 2.28 Å and the appearance of additional peaks in the low‐temperature diffraction data. A lower temperature ρ(T) anomaly at 205 K is related to subtle structural distortions involving chains of edge‐shared Cu4 tetrahedra.
New Heptazine Based Materials with a Divalent Cation – Sr[H2C6N7O3]2·4H2O and Sr[HC6N7(NCN)3]·7H2O
Authors: Braml Nicole E. , Schnick Wolfgang 
Published: August 2012

AbstractThe new heptazine based compounds Sr[H2C6N7O3]2·4H2O and Sr[HC6N7(NCN)3]·7H2O have been synthesized by metathesis reactions in aqueous solution. Crystal structures were studied by single‐crystal X‐ray diffraction and Rietveld refinement. Strontium cyamelurate tetrahydrate exhibits distorted zigzag strands embedding Sr2+ ions surrounded by crystal water molecules (Fdd2, a = 1194.0(17), b = 6358.14(97), c = 602.73(89) pm, Z = 8, GOF = 1.034, Rp = 0.033, wRp = 0.042, RB = 0.84). Strontium melonate heptahydrate crystallizes in a layer‐like structure characteristic for heptazine‐based compounds (P$\bar{1}$, a = 660.76(13), b = 1080.7(2), c = 1353.8(3) pm, α = 101.67(3), β = 101.40(3), γ = 94.60(3)°, Z = 2, R1 = 0.032, wR2 = 0.072). Additionally, the thermal behavior has been studied by DTA/TG measurements and FTIR spectroscopy data are presented.
Rheological and Microscopic Properties of Fat Blends with Similar Solid Fat Content but Different Trans Composition
Authors: Mert Behic , Erinc Hakan , Sahin Kubra , Tekin Aziz 
Published: August 2012

AbstractIn this study, two different groups of fat samples were prepared in a way that samples of each group had different trans fatty acid (TFA) composition but similar solid fat content (SFC). Samples of the first group (named group A) had TFA between 0.0 and 56.23 %, while the samples of the second group (group B) contained trans isomers ranging from 0.0 to 44.4 %. A polarized microscope was used to monitor the differences between the samples in terms of crystal size and crystal number during isothermal crystallization. In general, increasing TFA resulted in formation of larger crystals in a shorter time. Similar findings were also observed when small deformation time and frequency sweep experiments were conducted. A higher TFA content led to higher complex modulus values during isothermal crystallization. On the other hand, when the samples were stored at 4 °C for 48 h, the samples with the lower trans isomer had higher hardness values.
Stability of rotating non-smooth complex fluids
Authors: Sharma Ishan 
Published: August 2012

AbstractWe extend the classical energy criterion for stability, the Lagrange–Dirichlet theorem, to rotating non-smooth complex fluids. The stability test so developed is very general and may be applied to most rotating non-smooth systems where the spectral method is inapplicable. In the process, we rigourously define an appropriate coordinate system in which to investigate stability – this happens to be the well-known Tisserand mean axis of the body – as well as systematically distinguish perturbations that introduce angular momentum and/or jumps in the stress state from those that do not. With a view to future application to planetary objects, we specialize the stability test to freely rotating self-gravitating ellipsoids. This is then employed to investigate the stability to homogeneous perturbations of rotating inviscid fluid ellipsoids. We recover results consistent with earlier predictions, and, in the process, also reconcile some contradictory conclusions about the stability of Maclaurin spheroids. Finally, we consider the equilibrium and stability of freely rotating self-gravitating Bingham fluid ellipsoids. We find that the equilibrium shapes of most such ellipsoids are secularly stable to homogeneous perturbations that preserve angular momentum, but not otherwise. We also touch upon the effect of shear thinning on stability.
Boundary layer structure in confined turbulent thermal convection
Authors: Verzicco R. 
Published: August 2012

AbstractThe structure of viscous and thermal boundary layers at the heated and cooled plates in turbulent thermally driven flows are of fundamental importance for heat transfer and its dependence on the thermal forcing (the Rayleigh number $\mathit{Ra}$ in non-dimensional form). The paper by Shi, Emran & Schumacher (J. Fluid Mech., this issue, vol. 706, 2012, pp. 5–33) stresses the deviations of the boundary layer vertical profiles from the Prandtl–Blasius–Pohlhausen theory. Recent papers showing very similar results, in contrast, focus more on the similarities.
Impulsively actuated jets from thin liquid films for high-resolution printing applications
Authors: Brown Matthew S. , Brasz C. Frederik , Ventikos Yiannis , Arnold Craig B. 
Published: August 2012

AbstractBlister-actuated laser-induced forward transfer (BA-LIFT) is a versatile printing technique in which fine jets of ink are ejected from a thin donor film onto an acceptor substrate, enabling high-resolution patterns to be formed. Fluid ejections are initiated by the rapid expansion of micrometre-sized blisters that form on a polymer film underneath the ink layer. Recent work has demonstrated that these ejections exhibit novel flow phenomena due to the unique dimensions and geometry of the BA-LIFT configuration. In this work, we study the dynamics of BA-LIFT printing using a computational model in which fluid is forced by a boundary that deforms according to experimental time-resolved measurements of an expanding blister profile. This allows the model’s predictions to be unambiguously correlated with experimental blister-actuated ejections without any fitting parameters. First, we validate the model’s predictive capabilities against experimental results, including the ability to accurately reproduce the size, shape and temporal evolution of the jet as well as the total volume of ink released. The validated model is then used to interrogate the flow dynamics in order to better understand the mechanisms for fluid ejection. Finally, parametric studies are conducted to investigate the influence of ink density, surface tension, viscosity and film thickness as well as the size of the blister used. These results provide key insights into avenues for optimization and better control of the BA-LIFT process for improved resolution and repeatability of the printed features.
The catalytic role of the beta effect in barotropization processes
Authors: Venaille A. , Vallis G. K. , Griffies S. M. 
Published: August 2012

AbstractThe vertical structure of freely evolving, continuously stratified, quasi-geostrophic flow is investigated. We predict the final state organization, and in particular its vertical structure, using statistical mechanics and these predictions are tested against numerical simulations. The key role played by conservation laws in each layer, including the fine-grained enstrophy, is discussed. In general, the conservation laws, and in particular that enstrophy is conserved layer-wise, prevent complete barotropization, i.e. the tendency to reach the gravest vertical mode. The peculiar role of the$\ensuremath{\beta} $effect, i.e. of the existence of planetary vorticity gradients, is discussed. In particular, it is shown that increasing$\ensuremath{\beta} $increases the tendency toward barotropization through turbulent stirring. The effectiveness of barotropization may be partially parameterized using the Rhines scale$2\lrm{\pi} { E}_{0}^{1/ 4} / {\ensuremath{\beta} }^{1/ 2} $. As this parameter decreases ($\ensuremath{\beta} $increases) then barotropization can progress further, because the$\ensuremath{\beta} $term provides enstrophy to each layer. However, if the$\ensuremath{\beta} $effect is too large then the statistical mechanical predictions fail and wave dynamics prevent complete barotropization.
Influence of active control on STG-based generation of streamwise vortices in near-wall turbulence
Authors: Deng B.-Q. , Xu C.-X. 
Published: August 2012

AbstractNear-wall streamwise vortices are closely related to the generation of high skin friction in wall-bounded turbulent flows. A common feature of controlled, friction-reduced turbulent flows is weakened near-wall streamwise vortices. In the present study, the streak transient growth (STG) mechanism for generating near-wall streamwise vortices by Schoppa & Hussain (J. Fluid Mech., vol. 453, 2002, pp. 57–108) is employed, and the opposition control proposed by Choi, Moin & Kim (J. Fluid Mech., vol. 262, 1994, pp. 75–110) is imposed during the transient growth process of perturbations to determine how active control affects the generation of quasi-streamwise vortices. In the transient growth stage, when the detection plane is located near the wall (${ y}_{d}^{+ } = 15$), the control can suppress the production of streamwise vorticity by weakening the near-wall vertical velocity; when the detection plane moves away from the wall (${ y}_{d}^{+ } = 28$), the control has the opposite effect. In the vortex generation stage, the control cannot change the dominance of the stretching effect. Controls imposed at different stages reveal the importance of the STG stage in vortex generation. Strengthened out-of-phase control and lessened in-phase control are proposed as an extension of the original opposition-control scheme. Application in a fully developed turbulent channel flow shows that strengthened ${ y}_{d}^{+ } = 10$ control can yield an even higher drag reduction rate than the original ${ y}_{d}^{+ } = 15$ control. Moreover, lessened ${ y}_{d}^{+ } = 28$ control can also achieve drag reduction and turbulence suppression.