bluuebunny/crossref_metadata_2025_split huggingface dataset:
EPR study of chromium‐doped porous titanium dioxide
Authors: Pentegov I. S. , Konstantinova E. A. 
Published: December 2010

AbstractEPR study of chromium‐doped porous titanium dioxide samples has been carried out both in dark and under visible light illumination. Cr+3 spin centers located in subsurface layer and at the surface of the samples and O2–radicals were discovered in titanium dioxide and their dynamics under illumination of the samples was investigated. The number of Cr+3 spin centers correlates with content of chromium in the samples. Obtained data can be useful for development of chromium based TiO2 photocatalysts (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Fabrication of patterned porous silicon structures using a poly(N‐iso‐propylacrylamide) microgel mask and catalytic etching
Authors: Pacholski Claudia 
Published: December 2010

AbstractThe unique properties of porous silicon such as high surface area, well‐studied surface chemistry, and tuneable optical properties triggered its application in several areas such as sensing or optics. The performance of corresponding devices could be improved by the supply of micro/nanostructured porous silicon. Here, we report on the fabrication of patterned porous silicon using a combination of colloidal lithography and metal‐assisted etching. The method is solely based on chemical techniques and therefore is fast, cost‐efficient, and simple to perform. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electrical properties of InSb thin films with an InAsSb buffer layer grown by MOVPE
Authors: Homma Hideyuki , Nagata Hirotaka , Yamaguchi Shigeo 
Published: December 2010

AbstractWe have studied the electrical and thermoelectric properties of InSb thin films. The films were prepared by metalorganic vapor phase epitaxy on a sapphire substrate using an InAsSb buffer layer with a thickness of 0.9 nm, 2.6 nm, 5.1 nm, 10 nm, or 15 nm. The electrical and thermoelectric properties and the crystallinity of InSb thin films with an InAsSb buffer layer were evaluated. Maximum values of electron mobility and power factor were 10,240 cm2/Vs and 3.73 × 10‐4W/mK2, respectively, at room temperature for InSb with an InAsSb buffer layer of 5.1 nm thickness. On the basis of temperature dependence of electrical properties and a simulation, we proposed and showed that two‐conduction layers exist between InSb and substrate probably caused by their lattice‐mismatch. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Internal quantum efficiency and internal loss of ultraviolet laser diodes on the low dislocation density AlGaN underlying layer
Authors: Takeda Kenichiro , Nagata Kengo , Ichikawa Tomoki , Nonaka Kentaro , Ogiso Yuji , Oshimura Yoshinori , Iwaya Motoaki , Takeuchi Tetsuya , Kamiyama Satoshi , Akasaki Isamu , Amano Hiroshi , Yoshida Harumasa , Kuwabara Masakazu , Yamashita Yoji , Kan Hirofumi 
Published: December 2010

AbstractWe fabricated and evaluated GaN/AlGaN multi‐quantum wells (MQWs) and ultraviolet laser diodes (UV LDs) on high and low dislocation density underlying layers by epitaxial lateral overgrowth (ELO) method. We analyzed the internal quantum efficiency (IQE) versus carrier concentration characteristics quantitatively by excitation intensity dependent photoluminescence method. The IQE of the MQWs on the ELO AlGaN is 75% when the carrier density is 1x1019 cm‐3. We demonstrated the UV LD on the ELO AlGaN. However, the UV LD on flat AlGaN did not operate. Also, we investigated the internal loss (αi) and the IQE multiplied the injection efficiency by changing the reflectivity of the facets. The results showed that the internal loss is 6 cm‐1, and the IQE multiplied by the injection efficiency is 18% (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Low temperature (down to 450 °C) annealed TiAl contacts on N‐type gallium nitride characterized by differential scanning calorimetry
Authors: Thierry‐Jebali Nicolas , Menard Olivier , Chiriac Rodica , Collard Emmanuel , Brylinski Christian , Cayrel Frédéric , Alquier Daniel 
Published: December 2010

AbstractThis work reports on Differential Scanning Calorimetry (DSC) measurements performed on Ti‐Al metallic layers stacks deposited on n+‐GaN. The aim is to get better understanding of the mechanisms leading to ohmic contact formation during the annealing stage. Two exothermic peaks were found, one below 500 °C and the other one around 660 °C. They can be respectively attributed to Al3Ti and Al2Ti compounds formation. The locations of these peaks provide clear evidence of solid‐solid reactions. Lowest contact resistance is well correlated with the presence of Al3Ti compound, corresponding to Al(200nm)/Ti(50nm) stoichiometric ratio. Subsequently, Al(200 nm)Ti(50 nm) stacks on n+‐GaN were annealed from 400 °C to 650 °C. Specific Contact Resistivity (SCR) values stay in the mid 10‐5 Ω.cm² range for annealing temperatures between 450 °C and 650 °C. Such low‐temperature annealed contacts on n+‐GaN may open new device processing routes, simpler and cheaper, in which Ohmic and Schottky contacts are annealed together. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Analysis of excitation energy transfer in quantum dot clusters in the presence of nonluminescent dots
Authors: Miyazaki Jun , Kinoshita Shuichi , Jin Takashi 
Published: December 2010

AbstractWe studied the excitation energy transfer (EET) process in CdSe/CdZnS quantum dot (QD) clusters by measuring time‐ and spectrally‐resolved fluorescence intensities. Radiative and non‐radiative exciton recombinations that occurs after EET were evaluated: the latter occurred in a large class of QD ensembles because of the presence of nonluminescent (dark) QDs. Numerical simulation confirmed the effect of the dark QDs on time‐dependent fluorescence intensities, and the results were compared with that of the experiment. Nonradiative recombination occurring after EET was found to be dominant in the low quantum yield of QDs. The EET rate as a function of QD energy was successfully calculated on the basis of these findings. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Variational study of polaron dynamics with the Davydov Ansätze
Authors: Luo Bin , Ye Jun , Zhao Yang 
Published: December 2010

AbstractWe derive explicit expressions for the amplitudes of the deviation vectors for the time‐dependent Davydov D1, D2 and $ {\tilde {\rm D}} $ Ansätze from the exact solution of the Schrödinger equation for the Holstein polaron.By comparing the deviation amplitudes with the system energies, a systematic study is carried out on the validity of the Davydov Ansätze. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Switched system approach to stabilization of networked control systems
Authors: Yu Junyan , Wang Long , Yu Mei 
Published: December 2010

AbstractStabilization problems of networked control systems (NCSs) with bounded packet losses and transmission delays are addressed. We model such NCSs as a class of switched systems, and establish stabilizing conditions in the form of matrix inequalities by using packet‐loss dependent Lyapunov functions. By solving the inequalities, packet‐loss dependent controllers are designed for two types of packet‐loss processes: one is an arbitrary packet‐loss process, and the other is a Markovian packet‐loss process. Several numerical examples and simulations are worked out to demonstrate the effectiveness of the proposed design techniques. Copyright © 2010 John Wiley & Sons, Ltd.
Mesoporous materials: Why PMO? Towards Functionality and Utility of Periodic Mesoporous Organosilicas (Small 23/2010)
Authors: Wang Wendong , Lofgreen Jennifer E. , Ozin Geoffrey A. 
Published: December 2010

AbstractCreative synthetic chemistry has endowed the class of periodic mesoporous organosilica materials, dubbed PMO, with a variety of new and exciting compositions, properties, and functions since its inception a decade ago. Using a handful of recent trendsetting case histories, the multidisciplinary applications of PMO materials in chemistry and physics, materials science and engineering, biology, and medicine are demonstrated in a most powerful way. In doing so, this Review aims to inspire more collaborative and ambitious endeavors in the second decade of PMO research.
Functional and dynamic rheological properties of acetylated starches from two cultivars of cassava
Authors: Osundahunsi Oluwatooyin Faramade , Mueller Rudolf 
Published: December 2010

AbstractThe starches derived from two different cultivars of cassava were modified with acetic anhydride. The increase in swelling power and solubility of the cassava starch (CS) pastes treated with different acetic anhydride concentration could be attributed to easier hydration, resulting from reduction of interaction between starch chains due to the substitution. The transition temperatures (To, Tp and Tc) and enthalpy of gelatinisation (ΔH) of acetylated CS, were determined. The values were lower than those of native starches. Rheological properties of CS pastes (5% w/w) as a function of the degree of substitution were evaluated in dynamic shear force measurements. Magnitude of storage modulus (G′), loss modulus (G′′) and complex viscosity (Eta*) of acetylated CS pastes were determined also. Dynamic moduli (G′, G′′ and Eta*) values of acetylated sweet cultivar pastes were generally higher than those of native starch whereas the acetylated samples of the bitter cultivar were lower than those of native starch. The magnitudes of G′ were greater than those of G′′ and Eta* at all frequencies (ω). The fact that all the tan δ (ratio G′′/G′) values (0.7–0.48 and 0.25–0.44) were less than one is an indication that the samples are more elastic than viscous. The acetylated starches could find promising industrial uses in food products like Lemon curd and Mayonnaise and other non‐food applications.
Interactive instabilities of thin‐walled laminated composite pultrusion box columns
Authors: Kabir Mohammed Zaman , Shafei Erfan 
Published: December 2010

SUMMARYThe problem of interactive buckling and post‐buckling of intermediate length thin‐walled columns built of laminated plate elements subjected to compressive load has been proposed and solved analytically. Pultrusion columns have wide‐range applications in high‐rise building due to their low weight and high load carrying capacity. Classic stability theory and laminate theory were implemented to prove the existence of mixed‐mode buckling in thin‐walled pultrusion columns. Interactive stability modes can result in lower loading capacity of most compressive members and affects their post‐buckling behaviour in major proportions. Interactive buckling load analysis has been performed by means of a simplified theoretical model and verified by means of numerical analysis. The calculations were carried out for commonly used square section thin‐walled composite columns dimensions. The post‐buckling performance of selected sections has been investigated and an optimum layup configuration criterion for each section has been extracted according to pre‐ and post‐critical behaviour. Copyright © 2010 John Wiley & Sons, Ltd.
Adolescents' Declining Motivation to Learn Science: Inevitable or Not?
Authors: Vedder‐Weiss Dana , Fortus David 
Published: December 2010

AbstractThere is a growing awareness that science education should center not just on knowledge acquisition but developing the foundation for lifelong learning. However, for intentional learning of science to occur in school, out of school, and after school, there needs to be a motivation to learn science. Prior research had shown that students' motivation to learn science tends to decrease during adolescence [Anderman and Young [1994] Journal of Research in Science Teaching 31: 811–831; Lee and Anderson [1993] American Educational Research Journal 30: 585–610; Simpson and Oliver [1990] Science Education 74: 1–18]. This study compared 5th through 8th grade students' self‐reported goal orientations, engagement in science class, continuing motivation for science learning, and perceptions of their schools' and parents' goals emphases, in Israeli traditional and democratic schools. The results show that the aforementioned decline in adolescents' motivation for science learning in school and out of school is not an inevitable developmental trend, since it is apparent only in traditional schools but not in democratic ones. The results suggest that the non‐declining motivation of adolescents in democratic schools is not a result of home influence but rather is related to the school culture. © 2010 Wiley Periodicals, Inc., J Res Sci Teach 48: 199–216, 2011
Examining the effect of teachers' adaptations of a middle school science inquiry‐oriented curriculum unit on student learning
Authors: Fogleman Jay , McNeill Katherine L. , Krajcik Joseph 
Published: December 2010

AbstractReform based curriculum offer a promising avenue to support greater student achievement in science. Yet teachers frequently adapt innovative curriculum when they use them in their own classrooms. In this study, we examine how 19 teachers adapted an inquiry‐oriented middle school science curriculum. Specifically, we investigate how teachers' curricular adaptations (amount of time, level of completion, and activity structures), teacher self‐efficacy (teacher comfort and student understanding), and teacher experience enacting the unit influenced student learning. Data sources included curriculum surveys, videotape observations of focal teachers, and pre‐ and post‐tests from 1,234 students. Our analyses using hierarchical linear modeling found that 38% of the variance in student gain scores occurred between teachers. Two variables significantly predicted student learning: teacher experience and activity structure. Teachers who had previously taught the inquiry‐oriented curriculum had greater student gains. For activity structure, students who completed investigations themselves had greater learning gains compared to students in classrooms who observed their teacher completing the investigations as demonstrations. These findings suggest that it can take time for teachers to effectively use innovative science curriculum. Furthermore, this study provides evidence for the importance of having students actively engaging in inquiry investigations to develop understandings of key science concepts. © 2010 Wiley Periodicals, Inc., J Res Sci Teach 48: 149–169, 2011
The case of the boiled bladder – or, how to avoid medical errors
Authors: Kirby Roger , Dasgupta Prokar , Beacock Christopher 
Published: December 2010

AbstractNot too long ago, a disturbing case occurred in which a thermal injury was sustained by a patient as a result of the use of overheated irrigating fluid during a bladder tumour resection. Sadly, there was not a happy ending. The bladder never recovered from the trauma, but became shrunken and contracted, producing debilitating symptoms. A cystectomy and urinary diversion became necessary, but further complications set in, and eventually these were fatal. To the surprise of all concerned, litigation was not initiated by the family, although the hospital involved did offer a profound apology. So what lessons are there to be learned from so tragic an episode? Copyright © 2010 Wiley Interface Ltd
NLOOK: a computational attention model for robot vision
Authors: Heinen Milton Roberto , Engel Paulo Martins 
Published: December 2010

Abstract
The computational models of visual attention, originally proposed as cognitive models of human attention, nowadays are being used as front-ends to some robotic vision systems, like automatic object recognition and landmark detection. However, these kinds of applications have different requirements from those originally proposed. More specifically, a robotic vision system must be relatively insensitive to 2D similarity transforms of the image, as in-plane translations, rotations, reflections and scales, and it should also select fixation points in scale as well as position. In this paper a new visual attention model, called NLOOK, is proposed. This model is validated through several experiments, which show that it is less sensitive to 2D similarity transforms than other two well known and publicly available visual attention models: NVT and SAFE. Besides, NLOOK can select more accurate fixations than other attention models, and it can select the scales of fixations, too. Thus, the proposed model is a good tool to be used in robot vision systems.
Influences of the genetic neighborhood on ramet reproductive success in a clonal desert cactus
Authors: Carrillo‐Angeles Israel G. , Mandujano María C. , Golubov Jordan 
Published: December 2010

AbstractClonal structure in clonal plants can affect sexual reproduction. Individual ramets can decrease reproduction if their neighbors are ramets of the same genet due to inbreeding depression or self‐incompatibility. We assessed ramet reproductive success in the partial self‐incompatible Ferocactus robustus (Cactaceae) as a function of floral display size in focal ramets and floral display size and clonal structure of their reproductive neighborhoods. Ramets were labeled, sized in number of stems, mapped and genetically identified through RAPD markers in one population. A pollen dispersal area of 15‐m radius was established for each ramet to determine the clonal diversity in the neighborhoods. Flower production and fruit set were counted on a monthly basis during one reproductive season as a surrogate of ramet fitness. We expected a decrease in individual ramet reproductive success as a function of the number of reproductive ramets of the same genet in the neighborhood. A total of 272 sampled ramets revealed 116 multilocus genotypes, showing high clonal diversity in the population (G/N = 0.43, D = 0.98). Clonal diversity of neighborhoods ranged from 0.06 to 1 and fruit set varied from 0 to 76.9%. Individual ramet reproductive success was influenced by (1) mate availability, (2) floral display size of a genet within the reproductive neighborhood, and (3) the proportion of distinguishable genotypes. Floral display size of genets and ramets coupled with the genetic diversity within the reproductive neighborhood determines the low sexual reproduction in F. robustus.
Intraoperative Patient Skin Prep Agents: Is There a Difference?
Authors: Zinn Jennifer , Jenkins Jeanne B. , Swofford Vangela , Harrelson Beverly , McCarter Sharon 
Published: December 2010

AbstractFor health care institutions, intraoperative prep agents are a critical link in combating surgical site infections and the associated economic burden. The question remains, is there an intraoperative prep agent that is truly superior to the others? We conducted a literature review to examine available empirical evidence related to intraoperative prep agents used in our health system for open abdominal, general surgery procedures: povidone‐iodine, chlorhexidine gluconate, parachoroxylenol, and iodine povacrylex in 74% isopropyl alcohol. Intraoperative surgical skin prep studies were limited in providing empirical evidence to support one superior prep agent. Each prep agent has a specific mechanism of action along with specific advantages and disadvantages. We concluded that no one perioperative skin prep agent is superior in all clinical situations. Factors to consider when choosing an appropriate intraoperative skin prep agent include contraindications, environmental risks, the patient's allergies and skin condition, the surgical site, the manufacturer recommendations for the prep agent, and surgeon preference.
Particle motion driven by solute gradients with application to autonomous motion: continuum and colloidal perspectives
Authors: BRADY JOHN F. 
Published: December 2010

Diffusiophoresis, the motion of a particle in response to an externally imposed concentration gradient of a solute species, is analysed from both the traditional coarse-grained macroscopic (i.e. continuum) perspective and from a fine-grained micromechanical level in which the particle and the solute are treated on the same footing as Brownian particles dispersed in a solvent. It is shown that although the two approaches agree when the solute is much smaller in size than the phoretic particle and is present at very dilute concentrations, the micromechanical colloidal perspective relaxes these restrictions and applies to any size ratio and any concentration of solute. The different descriptions also provide different mechanical analyses of phoretic motion. At the continuum level the macroscopic hydrodynamic stress and interactive force with the solute sum to give zero total force, a condition for phoretic motion. At the colloidal level, the particle's motion is shown to have two contributions: (i) a ‘back-flow’ contribution composed of the motion of the particle due to the solute chemical potential gradient force acting on it and a compensating fluid motion driven by the long-range hydrodynamic velocity disturbance caused by the chemical potential gradient force acting on all the solute particles and (ii) an indirect contribution arising from the mutual interparticle and Brownian forces on the solute and phoretic particle, that contribution being non-zero because the distribution of solute about the phoretic particle is driven out of equilibrium by the chemical potential gradient of the solute. At the colloidal level the forces acting on the phoretic particle – both the statistical or ‘thermodynamic’ chemical potential gradient and Brownian forces and the interparticle force – are balanced by the Stokes drag of the solvent to give the net phoretic velocity.For a particle undergoing self-phoresis or autonomous motion, as can result from chemical reactions occurring asymmetrically on a particle surface, e.g. catalytic nanomotors, there is no imposed chemical potential gradient and the back-flow contribution is absent. Only the indirect Brownian and interparticle forces contribution is responsible for the motion. The velocity of the particle resulting from this contribution can be written in terms of a mobility times the integral of the local ‘solute pressure’ – the solute concentration times the thermal energy – over the surface of contact between the particle and the solute. This was the approach taken by Córdova-Figueroa & Brady (Phys. Rev. Lett., vol. 100, 2008, 158303) in their analysis of self-propulsion. It is shown that full hydrodynamic interactions can be incorporated into their analysis by a simple scale factor.
Pavel Rozhkov and Slava. ‘The first Soviet whalers in the Antarctic’
Authors: Bulkeley Rip 
Published: December 2010

ABSTRACTPavel Sergeyevich Rozhkov was captain of the whale catcher Slava 3 on the first Soviet whaling cruise in the Antarctic, which took place in 1946–1947. He wrote an exceptionally frank and detailed account of the cruise, for those times, which was published in a Lithuanian newspaper and is now presented here for the first time in English translation.