bluuebunny/crossref_metadata_2025_split huggingface dataset:
Diode laser‐based photoacoustic spectroscopy detection of acetylene gas and its quantitative analysis
Authors: Chen Weigen , Liu Bingjie , Zhou Hengyi , Wang Youyuan , Wang Caisheng 
Published: March 2011

SUMMARYAcetylene in oil is an important characteristic gas which reflects early discharge faults of transformer and other oil‐immersed electrical equipment. Laser‐based photoacoustic spectroscopy techniques of high sensitivity and good selectivity can be well applied to detect trace gases. A portable and tunable experimental setup with a distributed feedback diode laser has been developed in this paper. The photoacoustic cell property parameters, the relationships between the photoacoustic signals and the laser power and the acetylene gas concentrations were analysed experimentally. By means of diode laser wavelength modulation, the high‐resolution acetylene photoacoustic spectrum near 1.5 µm in the first overtone band near infrared was investigated. A novel method of photoacoustic quantitative analysis was proposed on the basis of least square regression. The theoretical and experimental results show the feasibility of on‐line monitoring of acetylene and designing a tunable photoacoustic spectrometer with high sensitivity. Copyright © 2011 John Wiley & Sons, Ltd.
A 16 000‐year record of vegetational change in south‐western Alaska as inferred from plant macrofossils and pollen
Authors: Kaltenrieder Petra , Tinner Willy , Lee Byoungyoon , Hu Feng Sheng 
Published: March 2011

AbstractPollen and macrofossil analyses of a sediment core from Beaver Pond (60° 37′ 14″ N, 154° 19′ W, 579 m a.s.l.) reveal a record of regional and local postglacial vegetation change in south‐western Alaska. The chronology is based on five AMS (accelerator mass spectrometry) 14C ages obtained from terrestrial plant macrofossils. Pollen and macrofossil records suggest that open herb and shrub tundra with e.g. Poaceae, Cyperaceae, Artemisia, Vaccinium and Salix prevailed on the landscape before ca. 14 000 cal a BP. The shift from herb‐ to shrub‐dominated tundra (Salix, subsequent Betula expansion) possibly reflects climatic warming at the beginning of the Bølling period at ca. 14 700–14 500 and around 13 500 cal a BP. Vegetation (Betula shrub tundra) remained relatively stable until the early Holocene. Macrofossil influx estimates provide evidence for greater biomass in Betula shrub tundra during the early postglacial period than today. Charcoal accumulation rates suggest tundra fire activity was probably greater from ca. 12 500 to 10 500 cal a BP, similar to results from elsewhere in Alaska. The pollen and macrofossil records of Beaver Pond suggest the prevalence of low shrub tundra (shrub Betula, Betula nana, Vaccinium, Ledum palustre, Ericaceae) and tall shrub tundra (Alnus viridis ssp. crispa, Salix) between 10 000 and 4000 cal a BP. This Holocene vegetation type is comparable with that of the modern treeless wet and moist tundra in south‐western Alaska. The expansion of Picea glauca occurred ∼4000 cal a BP, much later than that of A. viridis (ssp. crispa), whereas in central and eastern Alaska Picea glauca expanded prior to or coincident with Alnus (viridis). At sites located only 200–400 km north‐east of Beaver Pond (Farewell and Wien lakes), Picea glauca and Betula forests expanded 8000–6000 cal a BP. Unfavourable climatic conditions and soil properties may have inhibited the expansion and establishment of Picea across south‐west Alaska during the mid and late Holocene. Copyright © 2011 John Wiley & Sons, Ltd.
Cosmogenic nuclide constraints on glacial chronology in the source area of the Urumqi River, Tian Shan, China
Authors: Li Yingkui , Liu Gengnian , Kong Ping , Harbor Jon , Chen Yixin , Caffee Marc 
Published: March 2011

AbstractCosmogenic nuclide surface exposure dating of boulders and erratics provides new constraints for a glacial chronology in the source area of the Urumqi River, Tian Shan, China. 10Be exposure ages of 15.0 ± 1.3–17.1 ± 1.5 ka from the Upper Wangfeng (UWF) moraines agree well with their previous relative age assignments to marine isotope stage (MIS) 2, but are younger than published AMS 14C and electron spin resonance (ESR) ages (from 22.8 ± 0.6 to 37.4 ka). This difference may result from variations in techniques, or could reflect the impact of surface erosion and sediment/snow cover on surface exposure dating. 10Be ages from the Lower Wangfeng (LWF) moraines (18.7 ± 1.8 and 16.2 ± 1.5 ka) are indistinguishable from the UWF exposure ages, but are significantly younger than previously reported thermoluminescence (TL) and ESR ages (37.7 ± 2.6–184.7 ± 18 ka). Either these two groups were formed during the same period (MIS 2) and there are problems with TL and ESR ages, or the moraines were of very different ages and the similar exposure ages result from different degrees of degradation. Erratics on rock steps and a drumlin along >8 km of the main glacial valley above the UWF have internally consistent and slightly decreasing 10Be exposure ages indicating glacier retreat >2.5 m a−1 after MIS 2 and before middle or late Holocene glacier re‐advances. This retreat rate is similar to rates observed from modern glaciers. Copyright © 2011 John Wiley & Sons, Ltd.
Millennial‐scale fire and vegetation history from a mesic hardwood forest of southeastern Wisconsin, USA
Authors: Long Colin J. , Power Mitchell J. , Mcdonald Breanne 
Published: March 2011

AbstractHigh‐resolution charcoal analysis of lake sediment cores was used to reconstruct the fire history from two sites in a mesic hardwood forest of south‐eastern Wisconsin located in the Kettle Moraine State Forest. Pollen data from the region indicate that the sites, which lie within 5 km of each other, have had a consistent presence of mesic hardwood forest for the last 6500 years. A pollen record from one of the sites confirmed the regional vegetation history and the charcoal analysis indicated that fire frequency at each site was temporally linked to regional drought. Periods of high fire occurrence occurred in connection with a region‐wide drought 4200 years ago and, over the last 2000 years, shorter‐scale regional droughts were centred at 1800, 1650, 1100, 1000, 800, 700 and 600 cal a BP. The fire histories indicate that the last 1000 years have had lower fire frequencies than the previous 6500 years and suggest that the mesic hardwood forests may be resilient to increases in fire that may result from future climate change. Copyright © 2011 John Wiley & Sons, Ltd.
School‐based intervention programs for PTSD symptoms: A review and meta‐analysis
Authors: Rolfsnes Erika S. , Idsoe Thormod 
Published: March 2011

AbstractThis is a review and meta‐analysis of school‐based intervention programs targeted at reducing symptoms of posttraumatic stress disorder (PTSD). Nineteen studies conducted in 9 different countries satisfied the inclusionary criteria. The studies dealt with various kinds of type I and type II trauma exposure. Sixteen studies used cognitive–behavioral therapy methods; the others used play/art, eye movement desensitization and reprocessing, and mind‐body techniques. The overall effect size for the 19 studies was d = 0.68 (SD = 0.41), indicating a medium‐large effect in relation to reducing symptoms of PTSD. The authors' findings suggest that intervention provided within the school setting can be effective in helping children and adolescents following traumatic events.
Factor structure and concurrent validity of the Posttraumatic Growth Inventory–Short Form among veterans from the Iraq War
Authors: Kaler Matthew E. , Erbes Christopher R. , Tedeschi Richard G. , Arbisi Paul A. , Polusny Melissa A. 
Published: March 2011

AbstractThe Posttraumatic Growth Inventory is a frequently used self‐report measure of posttraumatic growth. It was adapted recently to a short form with preliminary evidence in support of its psychometric properties. The current survey study replicates evidence for the short form's factor structure, internal consistency reliability, and concurrent validity among a sample of 327 National Guard soldiers deployed in support of military operations in Iraq, a population distinct from the original scale‐development sample of undergraduates. Findings provide evidence for satisfactory reliability, replicable factor structure (i.e., the same 5‐factor structure as the original measure), and support for concurrent validity (i.e., relations with theoretically related constructs). Further research should address validity of the scale among more ethnically and racially heterogeneous samples.
Low‐Density Nanocellular Foams Produced by High‐Pressure Carbon Dioxide
Authors: Reglero Ruiz Jose Antonio , Dumon Michel , Pinto Javier , Rodriguez‐Pérez Miguel Angel 
Published: March 2011

AbstractA new type of nanocellular polymeric material based on PMMA and a MAM triblock copolymer is presented. The production avoids the use of physical additives and leads to completely homogeneous nanostructured polymers with a large number of CO2 nucleation sites. The foamed materials show average cell sizes <200 nm and relative foam densities of 0.4, presenting a homogeneous cell structure. A physical effect not measured before in nanocellular materials is demonstrated, which leads to an increase of the glass transition temperature due to the confining effect of PMMA chains in the cell walls of the nanocellular foam. The effects of changing saturation pressure and MAM content in the cellular structure are described, together with three‐point bending Young's modulus measured using DMA. magnified image
Modeling Film Drainage and Coalescence of Drops in a Viscous Fluid
Authors: Janssen Pieter J. A. , Anderson Patrick D. 
Published: March 2011

AbstractA proper description of coalescence of viscous drops is challenging from an experimental, numerical, and theoretical point of view. Although the problem seems easy at first sight, consensus in the literature has still not been reached on how to predict a realistic coalescence rate given flow type, capillary number and viscosity ratio. Despite advances in algorithms and computational power, and the emergence of fully‐closed analytical results, a match between theory, experiment and simulation for drainage rates only appears in a severely limited number of cases. In this paper, several recent developments are reviewed, and a summary is made of several challenges that still lay ahead. magnified image
Synergism Effect of Montmorillonite and Cellulose Whiskers on the Mechanical and Barrier Properties of Natural Rubber Composites
Authors: Bendahou Abdelkader , Kaddami Hamid , Espuche Eliane , Gouanvé Fabrice , Dufresne Alain 
Published: March 2011

AbstractA series of nanocomposite films based on natural rubber (NR), Na+‐montmorillonite (MMT), and cellulose whiskers (W) was prepared, keeping a total filler content equal to 5 wt.‐%. In the binary NR/MMT system, small stacks of intercalated montmorillonites were homogeneously dispersed within the polymer matrix whereas they were clearly lying in the vicinity of cellulose whiskers in the ternary NR/MMT/W blends. The effects of MMT and W on mechanical and gas barrier properties of the nanocomposite films were investigated. A significant increase of the rubbery modulus was obtained upon filler addition. The reinforcing effect was particularly important for the nanocomposite film reinforced with 1 wt.‐% MMT and 4 wt.‐% W. The improvement of the gas barrier properties observed upon filler addition was explained by a tortuosity effect. The calculated tortuosity values indicated that the simultaneous use of MMT and W could greatly slow down the gas diffusion rate in NR. Formation of MMT‐W subassembly should be responsible for this synergism effect. magnified image
QSAR Modelling of Rat Acute Toxicity on the Basis of PASS Prediction
Authors: Lagunin Alexey , Zakharov Alexey , Filimonov Dmitry , Poroikov Vladimir 
Published: March 2011

AbstractThe method for QSAR modelling of rat acute toxicity based on the combination of QNA (Quantitative Neighbourhoods of Atoms) descriptors, PASS (Prediction of Activity Spectra for Substances) predictions and self‐consistent regression (SCR) is presented. PASS predicted biological activity profiles are used as independent input variables for QSAR modelling with SCR. QSAR models were developed using LD50 values for compounds tested on rats with four types of administration (oral, intravenous, intraperitoneal, subcutaneous). The proposed method was evaluated on the set of compounds tested for acute rat toxicity with oral administration (7286 compounds) used for testing the known QSAR methods in T.E.S.T. 3.0 program (U.S. EPA). The several other sets of compounds tested for acute rat toxicity by different routes of administration selected from SYMYX MDL Toxicity Database were used too. The method was compared with the results of prediction of acute rodent toxicity for noncongeneric sets obtained by ACD/Labs Inc. The test sets were predicted with regards to the applicability domain. Comparison of accuracy for QSAR models obtained separately using QNA descriptors, PASS predictions, nearest neighbours’ assessment with consensus models clearly demonstrated the benefits of consensus prediction. Free available web‐service for prediction of LD50 values of rat acute toxicity was developed: http://www.pharmaexpert.ru/GUSAR/AcuToxPredict/
Retrospective Mapping of SAR Data for TTR Protein in Chemico‐Biological Space Using Ligand Efficiency Indices as a Guide to Drug Discovery Strategies
Authors: Blasi Daniel , Arsequell Gemma , Valencia Gregori , Nieto Joan , Planas Antoni , Pinto Marta , Centeno Nuria B. , Abad‐Zapatero Cele , Quintana Jordi 
Published: March 2011

AbstractWe have previously reported the design and synthesis of ligands that stabilize Transthyretin protein (TTR) in order to obtain therapeutically active compounds for Familial Amyloid Polyneuropathy (FAP). We are hereby reporting a drug design strategy to optimize these ligands and map them in Chemico‐Biological Space (CBS) using Ligand Efficiency Indices (LEIs). We use a binding efficiency index (BEI) based on the measured binding affinity related to the molecular weight (MW) of the compound combined with surface‐binding efficiency index (SEI) based on Polar Surface Area (PSA). We will illustrate the use of these indices, combining three crucial variables (potency, MW and PSA) in a 2D graphical representation of chemical space, to perform a retrospective mapping of SAR data for a current TTR inhibitors database, and we propose prospective strategies to use these efficiency indices and chemico‐biological space maps for optimization and drug design efforts for TTR ligands.
The process and effect of supportive message expression and reception in online breast cancer support groups
Authors: Kim Eunkyung , Han Jeong Yeob , Moon Tae Joon , Shaw Bret , Shah Dhavan V. , McTavish Fiona M. , Gustafson David H. 
Published: March 2011

AbstractObjective: To better understand the process and effect of social support exchanges within computer‐mediated social support (CMSS) groups for breast cancer patients, this study examines (1) the dynamic interplay between emotional support giving and receiving and (2) the relative effects of emotional support giving and receiving on patients' psychosocial health outcomes.Methods: Data was collected from 177 patients who participated in online cancer support groups within the Comprehensive Health Enhancement Support System (CHESS) during the 4‐month intervention. Data included (1) pretest and/or post‐test survey scores of demographic, disease‐related, and psychosocial factors, (2) automatically collected CHESS usage data, and (3) computer‐aided content analysis of social support messages posts.Results: Hierarchical regression analyses revealed that those who receive higher levels of support from others have fewer breast cancer‐related concerns (β = − 0.15, p<0.05), while those who give higher levels of support to others reframe their own problems in a positive light and adopt more positive strategies for coping (β = 0.16, p<0.05). In addition to these positive effects, partial correlation analysis indicated that these two supportive behaviors are reciprocal.Conclusions: We concluded that supportive exchanges of receiving and giving play positive, but different, roles in predicting psychosocial health outcomes. Moreover, emotional support giving and receiving tend to reinforce each other. Our findings help practitioners, health‐care providers, and health system designers make sense of diverse social support processes among cancer patients participating within CMSS groups. Copyright © 2011 John Wiley & Sons, Ltd.
Surface‐enhanced Raman scattering from gold deposited mesoporous silicon
Authors: Miyagawa Ryohei , Fukami Kazuhiro , Sakka Tetsuo , Ogata Yukio H. 
Published: March 2011

AbstractAs an SERS‐active template, Au deposited mesoporous Si was prepared by anodization of Si in hydrofluoric acid solution, followed by the displacement deposition of Au in solution containing Au(S2O3). The size and dispersion of deposited Au particles became small as the concentration of Au ions and the immersion duration decreased. The SERS‐activity measured with rhodamine 6G as the target molecule was affected by the morphology of Au deposits.
High quality 3D shapes by silicon anodization
Authors: Ivanov Alexey , Kovacs Andras , Mescheder Ulrich 
Published: March 2011

AbstractIn this paper some process considerations and optimizations of anodization for three‐dimensional (3D)‐structuring of silicon are discussed. For the shape controlling of etched form different approaches, such as frontside masking design, local backside doping and surface pre‐structuring are presented. Influences of the opening size and etch depth on the shape of the etching form are investigated. The surface quality of the resulting 3D structures is critically dependent on the specific process parameters and process flow. Best surface quality was obtained for electropolishing in 7 wt.% hydrofluoric acid (HF) at applied current densities of 100–300 mA/cm2. Application of 3D silicon forms for injection moulding is demonstrated and further implementations of the process for optical and fluidic devices are discussed.magnified image
3D silicon shapes fabricated using anodization process with local backside doping design.
On the way to meet the experimental observation of persistent current in a mesoscopic cylinder: A mean field study
Authors: Maiti Santanu K. 
Published: March 2011

AbstractThe behavior of persistent current in a mesoscopic cylinder threaded by an Aharonov–Bohm flux ϕ is carefully investigated within a Hartree–Fock mean field approach. We examine the combined effect of second‐neighbor hopping integral and Hubbard correlation on the enhancement of persistent current in presence of disorder. A significant change in current amplitude is observed compared to the traditional nearest‐neighbor hopping model and the current amplitude becomes quite comparable to experimental realizations. Our analysis is found to exhibit several interesting results which have so far remained unaddressed.
Efficient interdigitated back‐contacted silicon heterojunction solar cells
Authors: Mingirulli Nicola , Haschke Jan , Gogolin Ralf , Ferré Rafel , Schulze Tim F. , Düsterhöft J. , Harder Nils‐Peter , Korte Lars , Brendel Rolf , Rech Bernd 
Published: March 2011

AbstractWe present back‐contacted amorphous/crystalline silicon heterojunction solar cells (IBC‐SHJ) on n‐type substrates with fill factors exceeding 78% and high current densities, the latter enabled by a SiNx /SiO2 passivated phosphorus‐diffused front surface field. Voc calculations based on carrier lifetime data of reference samples indicate that for the IBC architecture and the given amorphous silicon layer qualities an emitter buffer layer is crucial to reach a high Voc, as known for both‐side contacted silicon heterojunction solar cells. A back surface field buffer layer has a minor influence. We observe a boost in solar cell Voc of 40 mV and a simultaneous fill factor reduction introducing the buffer layer. The aperture‐area efficiency increases from 19.8 ± 0.4% to 20.2 ± 0.4%. Both, efficiencies and fill factors constitute a significant improvement over previously reported values. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Constraint‐based human resource allocation in software projects
Authors: Kang Dongwon , Jung Jinhwan , Bae Doo‐Hwan 
Published: March 2011

AbstractResource allocation in a software project is crucial for successful software development. Among various types of resources, human resource is the most important as software development is a human‐intensive activity. Human resource allocation is very complex owing to the human characteristics of developers. The human characteristics affecting allocation can be grouped into individual‐level characteristics and team‐level characteristics. At the individual level, familiarity with tasks needs to be taken into account as it affects the performance of developers. In addition, developers have different levels of productivity, depending on their capability and experience; the productivity of developers also varies according to tasks. At the team level, characteristics such as team cohesion, communication overhead, and collaboration and management also affect human resource allocation. As these characteristics affect the efficiency of project execution, we treat them as constraints of human resource allocation in our approach. We identify individual‐level constraints and team‐level constraints based on the literature and interviews with experts in the industry. With these constraints, our approach optimizes the scheduling of human resource allocations, resulting in more realistic and efficient allocations. We also provide a guideline supporting various factors, with respect to roles and module characteristics, to estimate the productivity of developers based on COCOMO II. As productivity data are hard to obtain and manage, our guideline can provide a useful direction for human resource allocation in case of software projects. To validate our proposed approach, we document a case study using real project data. Copyright © 2011 John Wiley & Sons, Ltd.
Analyse von Deskriptorsystemen mit Hilfe von Berechnungsgraphen
Authors: Reinschke K. J. , Röbenack K. 
Published: March 2011

AbstractDer Beitrag ist der graphentheoretischen Analyse von Deskriptorsystemen mit unbestimmten Parametern gewidmet. Die Deskriptorgleichungen werden als Berechnungsabläufe interpretiert und im Berechnungsgraphen veranschaulicht. Mit Hilfe des Berechnungsgraphen und des zugehörigen Ableitungsgraphen lassen sich wichtige Charakteristiken bei linearen Deskriptorsystemen graphentheoretisch deuten und durch Inspektion der Graphen ermitteln. Ableseregeln für die Dimension des langsamen Teilsystems, die Anzahl und die Größe der Jordan‐Blöcke des schnellen Teilsystems und für die strukturellen Steuerbarkeitsmerkmale werden formuliert. Anhand der graphentheoretischen Bestimmung des relativen Grades wird gezeigt, daß Berechnungsgraphen an Kombination mit den Ableitungsgraphen auch für die Analyse nichtlinearer dynamischer Systeme nützlich sind.
Microstructural Decomposition Error Estimates
Authors: Zohdi T. , Wriggers P. 
Published: March 2011

AbstractComputational simulations of interacting microstructure in solid structures, with methods such as the finite element method, require solutions to numerically enormous boundary value problems. The primary objective of this work is to introduce a‐posteriori error bounds for a domain decomposition which can be used to reduce the computational complexity of boundary value problems associated with such simulations. The approach is to partition and decouple the heterogeneous body into more computationally tractable, nonoverlapping, subdomains whose union forms the entire domain under analysis. This is achieved by computing a relatively inexpensive auxiliary „decoupling problem”︁ with regularized coefficients but with the same external geometry and loading as the original body. The solution to the decoupling problem is then used to construct local boundary data for the subdomains, which can thereafter be solved independently, possibly in parallel.