bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sampling procedure simulating on‐the‐go sensing for soil nutrients
Authors: Schirrmann Michael , Domsch Horst 
Published: November 2010

AbstractThe emergence of a new sensor technology based on the use of ion‐selective membranes provides an increasing number of opportunities for on‐the‐go field measurements of soil nutrients and soil pH. In the future, on‐the‐go sensing should provide a cost‐effective monitoring of heterogeneous soils with high sampling resolution. It is suitable for site‐specific management because it can be focused on the spatial representativity of observation. This study evaluates the on‐the‐go‐sensing sampling design by comparing it with a standard approach to soil sampling for soil pH and the base nutrients P, K, and Mg under local field conditions in Germany. Soil samples were taken in two test sites at a resolution and in a manner as if they were sampled with an on‐the‐go sensing system and were compared with soil samples taken at a coarser resolution and with standard methods. In general, a higher variability was observed among the on‐the‐go samples due to their smaller sample support. The finer sampling resolution of the on‐the‐go design improved field‐scale semivariogram‐analysis results, identifying the spatial structures for soil pH, P, and Mg clearly. In addition, kriged maps of these soil parameters had predominantly higher estimation accuracies. However, the on‐the‐go samples were strongly influenced by the small‐scale variability of K in one of the test sites. This variability increased the kriging standard deviation for K by 50% compared with standard sampling design. Despite of this problem, the on‐the‐go‐sensing sampling design revealed field‐scale spatial variability for base nutrient status more accurately. Except for K, the mean absolute error of fertilizer‐application maps was reduced when using the on‐the‐go sample design in comparison with the standard sample design (Ca: 210/268 kg ha–1, P: 2.85/6.75 kg ha–1, K: 13.7/6.0 kg ha–1, Mg 5.7/6.8 kg ha–1). This will reduce over‐ and underfertilization using variable‐rate fertilizer‐application systems. In the future, it will be of interest if real on‐the‐go soil‐sensor measurements exhibit the same variability behavior addressed here or if results will differ substantially.
A critical evaluation of multi‐proxy dendroclimatology in northern Finland
Authors: McCarroll Danny , Tuovinen Mervi , Campbell Rochelle , Gagen Mary , Grudd Håkan , Jalkanen Risto , Loader Neil J. , Robertson Iain 
Published: November 2010

AbstractTwentieth‐century summer (July–August) temperatures in northern Finland are reconstructed using ring widths, maximum density and stable carbon isotope ratios (δ13C) of Scots pine tree rings, and using combinations of these proxies. Verification is based on the coefficient of determination (r2), reduction of error (RE) and coefficient of efficiency (CE) statistics. Of the individual proxies, δ13C performs best, followed by maximum density. Combining δ13C and maximum density strengthens the climate signal but adding ring widths leads to little improvement. Blue intensity, an inexpensive alternative to X‐ray densitometry, is shown to perform similarly. Multi‐proxy reconstruction of summer temperatures from a single site produces strong correlations with gridded climate data over most of northern Fennoscandia. Since relatively few trees are required (<15) the approach could be applied to long sub‐fossil chronologies where replication may be episodically low. Copyright © 2010 John Wiley & Sons, Ltd.
Quantitative structure–property relationship modeling of water‐to‐wet butyl acetate partition coefficient of 76 organic solutes using multiple linear regression and artificial neural network
Authors: Dashtbozorgi Zahra , Golmohammadi Hassan 
Published: November 2010

AbstractThe main aim of this study was the development of a quantitative structure–property relationship method using an artificial neural network (ANN) for predicting the water‐to‐wet butyl acetate partition coefficients of organic solutes. As a first step, a genetic algorithm‐multiple linear regression model was developed; the descriptors appearing in this model were considered as inputs for the ANN. These descriptors are principal moment of inertia C (IC), area‐weighted surface charge of hydrogen‐bonding donor atoms (HACA‐2), Kier and Hall index (order 2) (2χ), Balaban index (J), minimum bond order of a C atom (PC) and relative negative‐charged SA (RNCS). Then a 6‐4‐1 neural network was generated for the prediction of water‐to‐wet butyl acetate partition coefficients of 76 organic solutes. By comparing the results obtained from multiple linear regression and ANN models, it can be seen that statistical parameters (Fisher ratio, correlation coefficient and standard error) of the ANN model are better than that regression model, which indicates that nonlinear model can simulate the relationship between the structural descriptors and the partition coefficients of the investigated molecules more accurately.
Frequency and severity approaches to indexing exposure to trauma: The Critical Incident History Questionnaire for police officers
Authors: Weiss Daniel S. , Brunet Alain , Best Suzanne R. , Metzler Thomas J. , Liberman Akiva , Pole Nnamdi , Fagan Jeffrey A. , Marmar Charles R. 
Published: November 2010

AbstractThe Critical Incident History Questionnaire indexes cumulative exposure to traumatic incidents in police by examining incident frequency and rated severity. In over 700 officers, event severity was negatively correlated (rs = −.61) with frequency of exposure. Cumulative exposure indices that varied emphasis on frequency and severity—using both nomothetic and idiographic methods—all showed satisfactory psychometric properties and similar correlates. All indices were only modestly related to posttraumatic stress disorder (PTSD) symptoms. Ratings of incident severity were not influenced by whether officers had ever experienced the incident. Because no index summarizing cumulative exposure to trauma had superior validity, our findings suggest that precision is not increased if frequency is weighted by severity.
Dissemination of evidence‐based psychological treatments for posttraumatic stress disorder in the Veterans Health Administration
Authors: Karlin Bradley E. , Ruzek Josef I. , Chard Kathleen M. , Eftekhari Afsoon , Monson Candice M. , Hembree Elizabeth A. , Resick Patricia A. , Foa Edna B. 
Published: November 2010

AbstractUnlike the post‐Vietnam era, effective, specialized treatments for posttraumatic stress disorder (PTSD) now exist, although these treatments have not been widely available in clinical settings. The U.S. Department of Veterans Affairs (VA) is nationally disseminating 2 evidence‐based psychotherapies for PTSD throughout the VA health care system. The VA has developed national initiatives to train mental health staff in the delivery of Cognitive Processing Therapy (CPT) and Prolonged Exposure therapy (PE) and has implemented a variety of strategies to promote local implementation. In this article, the authors examine VA's national CPT and PE training initiatives and report initial patient, therapist, and system‐level program evaluation results. Key issues, lessons learned, and next steps for maximizing impact and sustainability are also addressed.
Continuing land degradation: Cause–effect in Ethiopia's Central Rift Valley
Authors: Meshesha D. T. , Tsunekawa A. , Tsubo M. 
Published: November 2010

AbstractThe Central Rift Valley (CRV) is one of the most environmentally vulnerable areas of Ethiopia. Most of the lowland in the CRV is arid or semiarid, and droughts occur frequently. We studied the dynamics of land use and cover and land degradation by analyzing Landsat data from 1973, 1985, and 2006 using Geographic Information Systems and remote sensing techniques. The analysis revealed that in the last 30 years, water bodies, forest, and woodland decreased by 15·3, 66·3, and 69·2 per cent, respectively; intensive cultivation, mixed cultivation/woodland, and degraded land increased by 34·5, 79·7, and 200·7 per cent. The major causes of land use and cover change (LUCC) and land degradation in the area were population and livestock growth in regions of limited resources, unsustainable farming techniques, the Ethiopian land tenure system and poverty. Lake level and area decline, and accelerated land degradation are the major environmental impacts of LUCC observed in the CRV. The environmental and socio‐economic consequences of LUCC and land degradation are far‐reaching. As a result of the expansion of land degradation over time, agricultural productivity has decreased and worsened food insecurity (shortages) and poverty in the Ethiopian CRV. In addition, if current trends in LUCC continue, Lake Abiyata will dry up by 2021. A detailed study of the degradation amount in relation to soil erosion, sediment yield to the lakes and catchment characteristics should be made using adaptable models; so as to guide the implementation of comprehensive and sustainable land use management by giving more attention to erosion prone areas. Copyright © 2010 John Wiley & Sons, Ltd.
Seeding and mulching + seeding effects on post‐fire runoff, soil erosion and species diversity in Galicia (NW Spain)
Authors: Fernández C. , Vega J.A. , Jiménez E. , Vieira D.C.S. , Merino A. , Ferreiro A. , Fonturbel T. 
Published: November 2010

AbstractThe effects of two different soil rehabilitation treatments on runoff, infiltration, erosion and species diversity were evaluated in a shrubland area in Galicia (NW Spain) after an experimental fire by means of rainfall simulations. The treatments compared were: seeding, seeding + mulching and control (untreated). Rainfall simulations were conducted 9 months after fire and the application of soil rehabilitation treatments. A rainfall rate of 67 mm h−1 was applied for 30 min to each runoff plot. Seeding significantly increased plant species richness in the treated plots relative to the control plots, although it had no effect on diversity or evenness. Rehabilitation treatments did not significantly increase soil cover or affect runoff and infiltration. Soil losses were low in all cases, varying from 75·6 kg ha−1 in the seeded + mulched plots to 212·1 kg ha−1 in the untreated plots. However, there were no significant differences in sediment yields between treatments. The percentage of bare soil appeared to be a critical variable in controlling runoff and erosion. Copyright © 2010 John Wiley & Sons, Ltd.
Synthesis of Water Soluble, Biodegradable, and Electroactive Polysaccharide Crosslinker with Aldehyde and Carboxylic Groups for Biomedical Applications
Authors: Wang Qian , He Wen , Huang Junqi , Liu Siwei , Wu Guifu , Teng Wei , Wang Qinmei , Dong Yugang 
Published: November 2010

AbstractWe report the synthesis and characterization of a polysaccharide crosslinker of tetraaniline grafting oxidized sodium alginate with large aldehyde and carboxylic groups. We demonstrate that this copolymer has the following properties: it is water soluble under any pH, biodegradable, electroactive, and noncytotoxic; it can self‐assemble into nanoparticles with large active functional groups on the outer surface; it can crosslink materials with amino and aminoderivative groups like gelatin to form hydrogels, and thus the electroactivity is readily introduced to the materials. This copolymer has potential applications in biomedical fields such as tissue engineering, drug delivery, and nerve probes where electroactivity is required. magnified image
Enhanced Photoluminescence, Mesomorphism and Conformation of Liquid‐Crystalline Conjugated Polymers with Terphenyl Mesogen Pendants
Authors: Chen Lie , Chen Yiwang , Zhou Dan , Li Fan , Zha Daijun , Yao Kai 
Published: November 2010

AbstractA variety of LCCPs containing terphenyl pendants based on polyacetylene, polythiophene, poly(p‐phenylene) and a poly(p‐phenylene) copolymer backbone have been synthesized. The effects of the structural variation on their properties, especially their mesomorphism, photoluminescence and secondary structures, were studied systematically. Longer alkoxy spacer favor stronger light emission and better mesomorphism. Disubstituted polyacetylenes show better developed mesomorphic textures, higher quantum yields and better thermal stability than their corresponding monosubstituted analogs. Steric effects and the “jacket‐ effect” from the mesogens cause the bulky terphenyl mesogen pendants to rotate around the main chain and force the main chain to assume a spiral conformation along the main chain in long range.
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Two‐Step Smectic CA Phase Formation from Isotropic Liquid upon Supercooling in Main‐Chain Liquid‐Crystalline BB‐5(1‐Me) Polyester
Authors: Ishige Ryohei , Tokita Masatoshi , Funaoka Shin‐ichiro , Kang Sungmin , Watanabe Junji 
Published: November 2010

AbstractThe mesophase formation process of a main‐chain BB‐5(1‐Me) polyester in the supercooled isotropic‐liquid state has been studied using DSC, WAXD, and optical microscopy. The supercooled isotropic liquid follows two different SmCA formation processes. Above 85 °C, it forms the expected SmCA phase. Below, it yields a metastable SmA phase that displays a layer spacing almost twice the one of the SmCA phase. The SmA phase develops from a homogeneous nucleation followed by 3D growth and thereafter transforms to the SmCA phase. This two‐step SmCA formation involves a change in polymer chain configuration: first, the chains are folded in each two units to form the SmA phase and then they stretch to achieve the characteristic zigzag arrangement of the mesogens in the SmCA phase. magnified image
An Intriguing Morphology Evolution of Polyoxometalate‐Polystyrene Hybrid Amphiphiles from Vesicles to Tubular Aggregates
Authors: Han Yao‐Kun , Zhang Zi‐Jian , Wang Yong‐Liang , Xia Nan , Liu Bo , Xiao Yu , Jin Liu‐Xin , Zheng Ping , Wang Wei 
Published: November 2010

AbstractThe originally synthesized hydrophobic hybrid polymer Bu4N+‐POM‐PS is tuned into a giant amphiphile composed of a hydrophilic H+‐POM head and a hydrophobic PS tail through protonation. Immediately, the hybrid amphiphiles self‐assemble into vesicles. A further annealing treatment induces an evolution from vesicles to tubular aggregates containing H+‐POM nanotubes wrapped with PS coronas. After this transformation, the tubular aggregates grow further and then arrange in a parallel manner to form domains. This interesting morphology evolution provides us an opportunity to understand the intriguing aggregation behavior of the hybrid amphiphiles and, meanwhile, to generate POM nanotubes which might be utilized to create nanomaterials for potential applications.
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Facile One‐Pot Approach for Preparing Functionalized Polymeric Nanoparticles via ROMP
Authors: Liu Jingwei , Liao Yang , He Xiaohua , Yu Jiahui , Ding Liang , Xie Meiran 
Published: November 2010

AbstractA facile approach to the preparation of functionalized polymeric nanoparticles with UV‐crosslinkable core and bromine‐bearing shell has been developed from the polymerization‐induced self‐assembly of the block copolymers PBNBE‐b‐PCONBI and PBNBE‐b‐PCONBI‐b‐PONBDM. The block copolymers were characterized by means of 1H NMR and GPC. The polymeric nanoparticles with a fixed shell length and varied core lengths were obtained through the control of the molar ratio of monomers in the feed. The micelles were crosslinked using UV‐irradiation, and the characteristics of the polymeric nanoparticles in toluene, THF, or CHCl3 before and after UV irradiation were investigated by means of DLS, UV‐Vis, GPC, AFM, and TEM.
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Assembly Properties of an Alanine‐Rich, Lysine‐Containing Peptide and the Formation of Peptide/Polymer Hybrid Hydrogels
Authors: Grieshaber Sarah E. , Nie Ting , Yan Congqi , Zhong Sheng , Teller Sean S. , Clifton Rodney J. , Pochan Darrin J. , Kiick Kristi L. , Jia Xinqiao 
Published: November 2010

AbstractAn alanine‐based peptide doped with charged lysines with a sequence of (AKA3KA)2 (AK2) was selected from the crosslinking regions of the natural elastin as a starting point for the fabrication of chemically diverse and structurally complex peptide/polymer hybrid hydrogels. At low peptide concentration, Pluronic F127 (F127) micelles are capable of increasing the peptide helicity and stabilizing it against thermal denaturation. At higher peptide concentration in basic media, the AK2 peptide developed a substantial amount of β‐sheet structure. The self‐assembled nanoscale structures were covalently interlocked. The crosslinked hybrid hydrogels were viscoelastic, exhibiting an elastic modulus of approximately 17 kPa and a loss tangent of 0.2. magnified image
Solid‐State Dye‐Sensitized Solar Cells with Conjugated Polymers as Hole‐Transporting Materials
Authors: Zhang Wei , Cheng Yueming , Yin Xiong , Liu Bin 
Published: November 2010

AbstractDSCs are a promising alternative to conventional silicon‐based solar cells owing to their low cost and relatively high efficiency. However, the utilization of a liquid electrolyte containing the iodine/iodide redox couple in traditional DSCs brings practical problems for their long‐term application, which leads to rapid development of SDSCs based on inorganic p‐type semiconductors or organic HTMs. In this review, we summarize the current research on SDSCs using conjugated polymer as HTM. Special attention is paid to understand the effects of polymer HTM structure and deposition process on SDSC performance. The limiting factors for SDSC energy conversion efficiency are discussed and strategies to improve device performance are proposed. magnified image
Rheological Behavior and Morphologies of Reactively Compatibilized PVDF/TPU Blends
Authors: Ma Haiying , Xiong Zhengrong , Lv Fengxian , Li Chan , Yang Yuming 
Published: November 2010

AbstractUsing the comb copolymer PVDF‐g‐AAc as a compatibilizer, five reactively compatibilized PVDF/TPU blends with different compositions were prepared. During melt blending, the carboxylic acid groups of PVDF‐g‐AAc react with the urethane linkages of TPU to generate the graft copolymers PVDF‐g‐AAc‐g‐TPU, which lead to compatibilization of the PVDF/TPU blends. The rheological behavior of the compatibilized PVDF/TPU blends can be described by a generalized Zener model. PVDF/TPU 50/50 and PVDF/TPU 30/70 blends show a particle network structure, indicating elastic interactions between the grafted shells of compatibilized PVDF domains. SEM shows that almost all compatibilized PVDF/TPU blends exhibit a dispersion‐type morphology. magnified image
Click‐Chemistry: An Alternative Way to Functionalize Poly(2‐methyl‐2‐oxazoline)
Authors: Volet Gisèle , Lav Thanh‐Xuan , Babinot Julien , Amiel Catherine 
Published: November 2010

AbstractCROP has been used to synthesize well‐defined POXZ with a monofunctional (iodomethane) or a bifunctional (1,3‐diiodopropane) initiator. POXZ has been functionalized with an azido group at one (α‐azido‐POXZ, $\overline {M} _{{\rm n}} $ = 3.58 × 103 g · mol−1) or both ends (α,ω‐azido‐POXZ, $\overline {M} _{{\rm n}} $ = 6.21 × 103 g · mol−1) of the macromolecular chain. The Huisgen 1,3‐dipolar cycloaddition has been investigated between azido‐POXZ and a terminal alkyne on a small or larger molecule (PEG). In each case, the click reaction has been successful and quantitative. In this way, different telechelic polymers (polymers bearing different functions such as acrylate, epoxide, or carboxylic acid) and block copolymers of POXZ and PEG have been prepared. The polymers have been characterized by means of FTIR, 1H NMR, and SEC. magnified image
Controlled Synthesis of Well Defined Poly(3‐hydroxyalkanoate)s‐based Amphiphilic Diblock Copolymers Using Click Chemistry
Authors: Babinot Julien , Renard Estelle , Langlois Valérie 
Published: November 2010

AbstractA modular synthesis of short chain length and medium chain length poly(3‐hydroxyalkanoate)s‐b‐poly(ethylene glycol) (PHAs‐b‐PEG) diblock copolymers is described. First, length‐controlled oligomers of hydrophobic poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) (PHBHV), poly(3‐hydroxybutyrate‐co‐3‐hydroxyhexanoate) (PHBHHx), and poly(3‐hydroxyoctanoate‐co‐hydroxyhexanoate) (PHOHHx) containing a carboxylic acid end group were obtained by thermal treatment, with molar masses ranging from 3 800 to 15 000 g · mol−1. After quantitative functionalization with propargylamine, ligation with azide‐terminated poly(ethylene glycol) of 5 000 g · mol−1 was accomplished using the copper (I) catalyzed azide alkyne cycloaddition (CuAAC). Well‐defined diblock copolymers were obtained up to 93% yield, with molar masses ranging from 9 900 to 23 100 g · mol−1. All products were fully characterized using 1H NMR, COSY, SEC, TGA, and DSC. magnified image
Nanostructured Polymer Blends: From Core/Shell Nanoobjects to Continuous Three‐Phase Morphologies
Authors: Lei Liangcai , Detrembleur Christophe , Jeusette Mélanie , Leclère Philippe , Lazzaroni Roberto , Jérôme Robert 
Published: November 2010

AbstractA PS‐b‐PIP‐b‐PMMA copolymer has been melt‐blended with homo‐PMMA with a similar molecular weight as the PMMA block. For a 50:50 wt.‐% mixture, the components form 3D bicontinuous lamellae. Upon annealing at 190 °C, a more regular network is observed, which consists of PMMA and 55 nm‐thick bilayered lamellae of triblock copolymer, both being continuous. This co‐continuity persists even when$\overline {M} _{{\rm n}} $of the homo‐PMMA is twice that of the PMMA block in the copolymer. For 30:70 and 20:80 wt.‐% copolymer/homopolymer pair, the copolymer forms cylindrical and spherical phases, respectively. Blends have also been prepared by solvent casting. Large domains of copolymer interconnected by few lamellae are observed in the 50:50 blend that reorganize into a bicontinuous network upon annealing.magnified image
Plasma Polymerization Surface Modification of Carbon Black and its Effect in Elastomers
Authors: Mathew Tony , Datta Rabin N. , Dierkes Wilma K. , Talma Auke G. , van Ooij Wim J. , Noordermeer Jacques W. M. 
Published: November 2010

AbstractSurface modification of carbon black by plasma polymerization was aimed to reduce its surface energy in order to compatibilize the filler with various elastomers. A fullerenic carbon black was used for the modification process. Thermogravimetric analysis, wetting behavior with liquids of known surface tension, TEM and TOF‐SIMS were used to characterize the carbon black before and after modification. The state of plasma‐coated carbon black in rubber was studied by means of conductivity measurements. The behavior of the modified filler in rubber was studied using the Payne effect and stress/strain properties. The study shows that plasma‐coated carbon black results in a better dispersion in different rubber systems than the uncoated version. magnified image
Dramatic Effects of Scalable SNN‐Assisted Melt Dispersion on Thermal Conductivity and Coefficient of Thermal Expansion of Nanocomposites
Authors: Kumar Sandeep , Lively Brooks , Liu Tian , Sun Lili , Tangpong Annie , Zhong Wei‐Hong 
Published: November 2010

AbstractIt is demonstrated that SNN‐assisted melt dispersion can lead to a significant improvement of the thermal conductivity of PC/MWCNT composites accompanied by a dramatic reduction in their linear CTE. The thermal conductivity of the SNN‐containing composites after the 2‐step process was about 95% higher than that of neat PC and 25% higher than that from 1‐step processing at same loading. The CTE below the glass‐transition temperature of composites with a 1.0 wt.‐% MWCNT loading is substantially reduced compared to the neat polymer. A reduction in the CTE of up to 60.8% is observed for composites from the 2‐step process. Simultaneous achievement of high thermal conductivity and low CTE is required for electronic packaging in microelectronics for device protection. magnified image