bluuebunny/crossref_metadata_2025_split huggingface dataset:
Bulk heterojunction polymer solar cells based on binary and ternary blend systems
Authors: Park Song Ju , Cho Jung Min , Byun Won‐Bae , Lee Jong‐Cheol , Shin Won Suk , Kang In‐Nam , Moon Sang‐Jin , Lee Sang Kyu 
Published: July 2011

AbstractPolymer solar cells (PSCs) were fabricated using a ternary blend film consisting two conjugated polymers and a soluble fullerene derivative as the donor and acceptor materials, respectively. And, to compare ternary blend system, the single‐component copolymers consisting of the repeating units of each of the copolymers, used in ternary blend solar cells, were designed and synthesized for use as the electron donor materials in binary blend solar cells. We systematically investigated the field‐effect carrier mobilities and the optical, electrochemical, and photovoltaic properties of the copolymers. Under optimized conditions, the binary blend polymer systems showed power conversion efficiencies (PCEs) for the PSCs in the range 3.87–4.16% under AM 1.5 illumination (100 mW cm−2). All polymers exhibited similar PCEs that did not depend on the ratio of repeating units. The binary blend solar cell containing a single‐component copolymer as the electron donor material performed better than the ternary blend solar cell in this work. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Copolymerization of norbornene with methoxycarbonylnorbornene catalyzed by Ni{CF3C(O)CHC[N(naphthyl)]CH3}2/B(C6F5)3 catalytic system and good processability for Dry/Wet phase inversion and electrospinning technique
Authors: Xing Yuepeng , Chen Yiwang , He Xiaohui 
Published: July 2011

AbstractCopolymerization of norbornene (NB) with methoxycarbonylnorbornene (NB‐COOCH3) was carried out with catalytic system of Ni{CF3C(O)CHC[N(naphthyl)]CH3}2 and B(C6F5)3 in toluene. The catalytic system exhibited higher activity 2.69 × 105 (gpolymer/mol Ni h) for copolymerization of norbornene and methoxycarbonylnorbornene. The influence results of the comonomer feed content on the polymerization showed that the NB‐COOCH3 has a very high insertion ratio in all copolymers, and the NB‐COOCH3 content in copolymers can be controlled to be 7.9–77.6 mol % at content of 10–90 mol % of the NB‐COOCH3 in the monomer feeds ratios. The reactivity ratios, rNB‐COOCH3 = 0.578 and rNB = 0.859, were determined by the Kelen–TÜdÕs method. Copolymers were processed by solution casting method, dry/wet phase inversion technique, and electrospinning. The films prepared by solution casting method showed good transparency in the visible region. The membranes processed by dry/wet phase inversion technique were microporous structures. The fibers diameters fabricated by electrospinning were about 3 μm. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Novel perfluorocyclobutyl aryl ether‐based well‐defined amphiphilic block copolymer
Authors: Yao Wenqiang , Li Yongjun , Zhang Sen , Liu Hao , Huang Xiaoyu 
Published: July 2011

AbstractA series of fluorine‐containing amphiphilic diblock copolymers comprising hydrophobic poly(p‐(2‐(p‐tolyloxy)perfluorocyclobutoxy)phenyl methacrylate) (PTPFCBPMA) and hydrophilic poly(2‐(diethylamino)ethyl methacrylate) (PDEAEMA) segments were synthesized via successive reversible addition fragmentation chain transfer (RAFT) polymerizations. RAFT homopolymerization of p‐(2‐(p‐tolyloxy)perfluorocyclobutoxy)phenyl methacrylate was first initiated by 2,2′‐azobisisobutyronitrile using cumyl dithiobenzoate as chain transfer agent, and the results show that the procedure was conducted in a controlled way as confirmed by the fact that the number‐average molecular weights increased linearly with the conversions of the monomer while the polydispersity indices kept below 1.30. Dithiobenzoate‐capped PTPFCHPMA homopolymer was then used as macro‐RAFT agent to mediate RAFT polymerization of 2‐(diethylamino)ethyl methacrylate, which afforded PTPFCBPMA‐b‐PDEAEMA amphiphilic diblock copolymers with different block lengths and narrow molecular weight distributions (Mw/Mn ≤ 1.28). The critical micelle concentrations of the obtained amphiphilic diblock copolymers were determined by fluorescence spectroscopy technique using N‐phenyl‐1‐naphthylamine as probe. The morphology and size of the formed micelles were investigated by transmission electron microscopy and dynamic light scattering, respectively. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Photoresponsive self‐assembling structures from a pyrene‐based triblock copolymer
Authors: Menon Sajith , Das Suresh 
Published: July 2011

AbstractA new photoresponsive amphiphilic triblock copolymer, poly(pyrenylmethyl methacrylate)‐block‐polystyrene‐block‐poly(ethylene oxide) (PPy‐b‐PSt‐b‐PEO), was synthesized using atom‐transfer radical polymerization. Formation of colloidal aggregates of the polymer was observed in solutions under controlled conditions due to the amphiphilic nature of the polymer. Irradiation of the polymer aggregates using UV light resulted in the photodissociation of 1‐pyrenemethanol units from the polymer back‐bone resulting in break‐up of the aggregates mainly due to the hydrophilic nature of the residual polymer. The use of these polymer aggregates to trap hydrophobic fluorescent dyes in water and its controlled release on exposure to UV light has also been explored. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Glow‐discharge Electrolysis Plasma Induced Synthesis of Polyvinylpyrrolidone/Acrylic Acid Hydrogel and its Adsorption Properties for Heavy‐metal Ions
Authors: Lu Quanfang , Yu Jie , Gao Jinzhang , Yang Wu , Li Yan 
Published: July 2011

AbstractPolyvinylpyrrolidone/acrylic acid (PVP/AAc) hydrogel is synthesized using glow‐discharge electrolysis plasma (GDEP) technique in an aqueous solution. To optimize the synthesis conditions, the following parameters are examined in detail: discharge voltage, discharge time, mass ratio of PVP to AAc, and content of crosslinker to acrylic acid. The properties of hydrogels are characterized by thermogravimetric analysis (TGA), scanning electron microscopy (SEM), energy dispersive X‐ray spectrometer (EDS), Fourier transform infrared spectroscopy (FT‐IR), and X‐ray photoelectron spectroscopy (XPS). The results show that both chemical complexation and ion‐exchange play an important role for Pb(II) adsorption onto PVP/AAc hydrogel. Langmuir and Freundlich adsorption models are applied to describe the isotherms at room temperature, and a good agreement between the Langmuir model the experimental data is obtained.magnified image
Laboratory and field comparisons of insecticides to reduce infestation of Drosophila suzukii in berry crops
Authors: Bruck Denny J , Bolda Mark , Tanigoshi Lynell , Klick Jimmy , Kleiber Joseph , DeFrancesco Joe , Gerdeman Beverly , Spitler Hollis 
Published: July 2011

AbstractBACKGROUND: The spotted wing Drosophila, Drosophila suzukii (Matsumura, 1931) (Diptera: Drosophilidae), is an invasive pest of small‐fruit crops. Unlike most other Drosophila, this insect is able to oviposit into and damage ripe and ripening fruit, making it unmarketable. Because this is a new pest in the United States, it is necessary to identify registered insecticides to manage this insect effectively in conventional and organic production systems.RESULTS: The present laboratory bioassays and field trials identified a number of insecticides representing various modes of action that are effective in controlling D. suzukii. Products that performed well in the laboratory bioassay also performed well in the field, indicating that screening of new chemistries in the laboratory is a worthy exercise. Field application of pyrethoids, organophosphates or spinosyns provided 5–14 days of residual control of D. suzukii. The efficacy of the neonicotinoids as adulticides was not satisfactory compared with the other contact‐mode‐of‐action chemistries. Based on the zero tolerance by the small‐fruit industry and the individual effects mentioned above, neonicotinoids are not currently recommended for D. suzukii management.CONCLUSIONS: There are effective insecticides registered for controlling D. suzukii infestations in susceptible small‐fruit crops. Copyright © 2011 Society of Chemical Industry
Pyrethroid insecticide resistance in British populations of the cabbage whitefly, Aleyrodes proletella
Authors: Springate Simon , Colvin John 
Published: July 2011

AbstractBACKGROUND: The cabbage whitefly, Aleyrodes proletella L., is emerging as a significant pest of field brassica crops in certain regions of the United Kingdom. In order to investigate the contribution of pesticide resistance to this phenomenon, A. proletella populations were sampled from five different areas in England in 2008 and 2009. Adult residual leaf‐dip bioassays were carried out using pyrethroid and neonicotinoid insecticides.RESULTS: Significant resistance to pyrethroids was found in multiple samples collected from two areas. No evidence of cross‐resistance to neonicotinoids was found in a subset of the pyrethroid‐resistant populations. While the patterns of resistance to different pyrethroids were broadly correlated, the magnitude of resistance factors differed substantially. Survival of strains at a putative diagnostic concentration of lambda‐cyhalothrin was found to provide a guide to their LC50. Significant differences in LC50 were found when different brassica crops were used in the bioassay, although the resistance patterns between strains were maintained.CONCLUSION: Reduced susceptibility to multiple pyrethroid insecticides exists in populations of A. proletella in the United Kingdom, corresponding to recent major outbreaks. The mechanism(s) of resistance are yet to be determined, but molecular structural differences in pyrethroids probably influence the magnitude of cross‐resistance within this group of insecticides. Copyright © 2011 Society of Chemical Industry
Mid‐infrared emission from Er3+ and energy transfer in Er3+–Yb3+ and Er3+–Nd3+ co‐doped Ga2S3–GeS2–Sb2S3 glasses
Authors: Ichikawa Manabu , Ishikawa Yoichi , Wakasugi Takashi , Kadono Kohei 
Published: July 2011

AbstractThe radiative and nonradiative transitions of the first three excited levels of Er3+ doped in Ga2S3–GeS2–Sb2S3 glass were investigated. Particularly, we focused on the 4I9/2 and 4I11/2 which are the initial and final levels of mid‐infrared emission around 4 µm. The effects of energy transfer from these levels to co‐doped rare‐earth ions, Yb3+ and Nd3+, were estimated. The population of the final level, 4I11/2, was efficiently quenched by the energy transfer to the Yb3+, 2F5/2 level. This leads to the population inversion between the initial and final levels. In the Nd3+‐co‐doped glass, on the contrary, the initial level, 4I9/2, was more rapidly quenched than the final level, 4I11/2, through the energy transfer to Nd3+, 4F5/2 + 2H9/2.
Electric field induced dynamics of charged species in metal oxide devices: Diffusion equation analysis
Authors: Kiselev I. , Sommer M. , Sysoev V. V. , Skorokhodov S. L. 
Published: July 2011

AbstractDistributions of charged species over metal oxide appearing after a step‐like voltage bias application and under the alternate voltage respectively are examined in framework of the diffusion initial‐boundary value problem. When possible, the solutions are derived in analytical form to make general conclusions. The solutions obtained are helpful in particular to ascertain limits of the diffusion approach to explain the transient behavior of non‐linear electric potential distributions over gas sensitive metal oxide films and the low‐frequency abnormalities of impedance spectra of such films.
Mechanical loss of calcium fluoride at cryogenic temperatures
Authors: Schwarz Christian , Heinert Daniel , Seidel Paul , Tünnermann Andreas , Hammond Giles D. , Nawrodt Ronny 
Published: July 2011

AbstractLow mechanical loss materials are in great demand for micro‐mechanical applications as well as high precision instrumentation. We describe low mechanical loss measurements of a calcium fluoride (CaF2) bulk sample. A new mechanical relaxation process was observed for frequencies in the range from 31 to 64 kHz and temperatures of 10 to 50 K. The activation energy of this process was found to be 10 meV. This relaxation process increases the mechanical loss significantly and thus sets limits to the application of this material at these temperatures.
Effects of jackfruit waste flour on the properties of poly(vinyl alcohol) film
Authors: Ooi Z.X. , Ismail H. , Abu Bakar A. , Aziz N.A. 
Published: July 2011

AbstractA series of biodegradable polymer films based on poly(vinyl alcohol) (PVOH) and jackfruit waste flour (JWF) was prepared in the presence of water and glycerol and cast by a solution casting method. The JWF was introduced as a promoter of biodegradability. The blended films were evaluated for their tensile properties, water absorption, water vapor transmission rate (WVTR), and degradation behavior under different environmental conditions such as natural weathering and natural soil. The tensile strength (1.7–6.4 MPa) and elongation at break (13–108%) of the PVOH/JWF films were lower than those of unfilled PVOH film (26MPa and 238%). However, the Young's modulus values (157–196 MPa) of the PVOH/JWF films were higher than that of unfilled PVOH film (137 MPa). The PVOH/JWF blended films showed higher water absorption and WVTR, which increased with increasing JWF content. Biodegradability tests revealed that the presence of JWF stimulated the degradation rate and caused the weight loss and reduction in tensile properties of the PVOH/JWF blended films. J. VINYL ADDIT. TECHNOL., 2011. © 2011 Society of Plastics Engineers
Preparation and evaluation of some benzophenone terpolymers as photostabilizers for rigid PVC
Authors: Braun Dietrich , Rabie Samira T. , Khaireldin Nahid Y. , Abd El‐Ghaffar Mahmoud A. 
Published: July 2011

AbstractSome terpolymeric stabilizers based on polymerizable derivatives of 2,4‐dihydroxy‐benzophenone were prepared and evaluated as photostabilizers for rigid poly(vinyl chloride) (PVC). The prepared terpolymers, namely, (methyl methacrylate)/(2‐hydroxyethyl methacrylate)/2‐hydroxy‐4‐methacryloxybenzophenone (MMA/HEMA/HBMA) and (methyl methacrylate)/(2‐hydroxyethyl methacrylate)/2‐hydroxy‐4‐(3‐methacryloxy‐2‐hydroxypropoxy)benzophenone (MMA/HEMA/PBMA), were characterized, and their structures were confirmed by GPC, thermogravimetric analysis, FTIR, and ultraviolet‐visible (UV–vis) spectroscopy. The results revealed that the stabilizing effect of these terpolymers increased upon increasing the stabilizer concentration and the content of UV absorber units in the terpolymers. Promising results were achieved, and the prepared terpolymers showed higher stabilizing efficiency than the corresponding monomeric UV absorbers of low molecular weight. J. VINYL ADDIT. TECHNOL., 2011.© 2011 Society of Plastics Engineers
The use of decision trees for cost‐sensitive classification: an empirical study in software quality prediction
Authors: Seliya Naeem , Khoshgoftaar Taghi M. 
Published: July 2011

AbstractThis empirical study investigates two commonly used decision tree classification algorithms in the context of cost‐sensitive learning. A review of the literature shows that the cost‐based performance of a software quality prediction model is usually determined after the model‐training process has been completed. In contrast, we incorporate cost‐sensitive learning during the model‐training process. The C4.5 and Random Forest decision tree algorithms are used to build defect predictors either with, or without, any cost‐sensitive learning technique. The paper investigates six different cost‐sensitive learning techniques: AdaCost, Adc2, Csb2, MetaCost, Weighting, and Random Undersampling (RUS). The data come from case study include 15 software measurement datasets obtained from several high‐assurance systems. In addition, to a unique insight into the cost‐based performance of defection prediction models, this study is one of the first to use misclassification cost as a parameter during the model‐training process. The practical appeal of this research is that it provides a software quality practitioner with a clear process for how to consider (during model training) and analyze (during model evaluation) the cost‐based performance of a defect prediction model. RUS is ranked as the best cost‐sensitive technique among those considered in this study. © 2011 John Wiley & Sons, Inc. WIREs Data Mining Knowl Discov 2011 1 448–459 DOI: 10.1002/widm.38This article is categorized under:

Algorithmic Development > Hierarchies and Trees
Technologies > Classification
Technologies > Prediction
On the limits of refinement-testing for model-checking CSP
Authors: Murray Toby 
Published: July 2011

Abstract
Refinement-checking, as embodied in tools like FDR, PAT and ProB, is a popular approach for model-checking refinement-closed predicates of CSP processes. We consider the limits of this approach to model-checking these kinds of predicates. By adopting Clarkson and Schneider’s hyperproperties framework, we show that every refinement-closed denotational predicate of finitely-nondeterministic, divergence-free CSP processes can be written as the conjunction of a safety predicate and the refinement-closure of a liveness predicate. We prove that every safety predicate is refinement-closed and that the safety predicates correspond precisely to the CSP refinement checks in finite linear observations models whose left-hand sides (i.e. specification processes) are independent of the systems to which they are applied. We then show that there exist important liveness predicates whose refinement-closures cannot be expressed as refinement checks in any finite linear observations model , divergence-strict model or non-divergence-strict divergence-recording model , i.e. in any standard CSP model suitable for reasoning about the kinds of processes that FDR can handle, namely finitely-branching ones. These liveness predicates include liveness properties under intuitive fairness assumptions, branching-time liveness predicates and non-causation predicates for reasoning about authority. We conclude that alternative verification approaches, besides refinement-checking, currently under development for CSP should be further pursued.
The Methods of Reconstruction of Pancreatic Digestive Continuity After Pancreaticoduodenectomy: A Meta‐Analysis of Randomized Controlled Trials
Authors: Yang Sun Hu , Dou Ke Feng , Sharma Neel , Song Wen Jie 
Published: July 2011

AbstractBackgroundPancreatic fistula (PF) is an important factor responsible for the considerable morbidity associated with pancreaticoduodenectomy (PD). There have been many techniques proposed for the reconstruction of pancreatic digestive continuity to prevent fistula formation but which is best is still highly debated. We carried out a systematic review and meta‐analysis to determine the effectiveness of methods of anastomosis after PD.MethodsA full literature search was conducted in the Cochrane Controlled Trials Register Databases, Medline, and other resources irrespective of language. Randomized controlled trials (RCTs) were considered for inclusion. Analyses were carried out using RevMan software.ResultsIn all, ten RCTs that included a total of 1,408 patients were included. The meta‐analysis showed that the PF, postoperative complications, biliary fistula, mortality, reoperation, and length of hospital stay were not statistically different between the pancreaticogastrostomy (PG) and pancreaticojejunostomy (PJ) groups. The PF, postoperative complications, mortality, and reoperation were not statistically different between the duct‐to‐mucosa PJ and PJ groups. Binding PJ significantly decreased the PF and postoperative complications compared with conventional PJ. The PF, postoperative complications, and mortality were not statistically different between ligation of the pancreatic duct without anastomosis versus PJ.ConclusionNo pancreatic reconstruction technique after PD was found to be applicable to all kinds of pancreatic remnants in our systematic review and meta‐analysis. Some new approaches such as binding PJ and modified PG will be considered for study in the future.
Evaluation of an Improved Indirect Method for the Analysis of 3‐MCPD Esters Based on Acid Transesterification
Authors: Ermacora Alessia , Hrncirik Karel 
Published: July 2011

AbstractThe quantification of 3‐chloropropane‐1,2‐diol (3‐MCPD) esters in fat‐based matrices is currently carried out according to a number of methods that involve either the conversion of all the esters to the free form that is then quantified (indirect methods), or the separation and quantification of the individual esters (direct methods). Indirect methods of analysis show a better sensitivity, however, the series of chemical reactions that take place during sample preparation may affect the reliability of the results because of the potential ex‐novo formation of 3‐MCPD from precursors present in the sample. This study is focused on the evaluation of the selectivity and robustness of an indirect acid‐catalysed method of 3‐MCPD esters analysis. The interference of chloride ions and glycidyl esters was evaluated. 3‐MCPD esters are overestimated only when high levels of chloride ions (>1.7 mmol/kg oil) were added to the samples. The interference by chloride ions can be easily eliminated by a single extraction step of the samples before analysis. In contrast, glycidyl esters did not interfere with the determination of 3‐MCPD esters. Further investigation on the robustness of the method showed that the time allowed for the transesterification, a major drawback of the previous version of the method, can be reduced from 16 to 4 h without any significant reduction of the accuracy and repeatability (RSD = 0.7%).
Le principe de l’anonymat du don de sperme: remarques sur son histoire et son application
Authors: Bateman S. 
Published: July 2011

Résumé

Introduction
Cet article, basé sur des recherches sociologiques menées sur l’activité d’insémination artificielle et de conservation de sperme, vise à répondre à quatre questions relatives à la politique actuelle d’anonymat du don du sperme: qu’est-ce que le principe d’anonymat du don de sperme ? D’où vient-il ? Quelle fonction remplit-il dans l’organisation de la pratique d’insémination artificielle avec sperme de donneur (IAD) ? Comment s’applique-t-il au quotidien ?

Matériel et méthodes
L’analyse des origines de cette politique et de son évolution repose sur des documents des années 1970 et 1980, qui permettent de reconstituer l’histoire de la pratique de l’IAD, en particulier celle menée dans le cadre des règles proposées par les Centres d’étude et de conservation du sperme (Cecos).

Résultats
Il en ressort que l’anonymat du don de sperme est une politique effective depuis au moins deux siècles, tandis que la notion d’un principe d’anonymat est relativement récente.

Conclusion
Sa remise en question aujourd’hui met à jour des interrogations persistantes sur ce qui constitue la paternité lorsque celle-ci est dissociée de l’engendrement.
Impact of running away on girls’ pregnancy
Authors: Thrane Lisa E. , Chen Xiaojin 
Published: July 2011

ABSTRACTThis study assessed the impact of running away on pregnancy in the subsequent year among U.S. adolescents. We also investigated interactions between running away and sexual assault, romance, and school disengagement. Pregnancy among females between 11 and 17 years (n = 6100) was examined utilizing the Longitudinal Study of Adolescent Health (Add Health) data from Waves 1 and 2. The odds of pregnancy in the next year were 1.67 times greater for runaways net of other factors. A history of sexual assault and romantic involvement increased the likelihood of pregnancy. The relationship between pregnancy and runaway behavior in the general population is understudied. Our findings suggest that runaway youth have a multiplicity of needs that require a complex array of medical, social, emotional, and academic resources to promote positive sexual health outcomes.