bluuebunny/crossref_metadata_2025_split huggingface dataset:
Permanent antistatic polypropylene based on polyethylene wax/polypropylene wax‐grafting sodium acrylate
Authors: Xu Xiang , Xiao Huining , Guan Yong , Li Shuzhao , Wei Dafu , Zheng Anna 
Published: May 2012

AbstractTwo types of permanent antistatic agents, polyethylene wax grafted with sodium acrylate (PEW‐g‐AAS) and polypropylene (PP) wax grafted with sodium acrylate (PPW‐g‐AAS), were prepared using a solution grafting method and applied to PP to enhance antistatic properties. The grafting degree was determined using back titration method, and structures were confirmed by Fourier transform infrared spectroscopy. The antistatic properties of PEW‐g‐AAS/PP blends and PPW‐g‐AAS/PP blends were characterized by surface resistivities (ρs) and volume resistivities (ρv), and a combination of contact angle measurement, scanning electron microscopy, permittivity, and dielectric loss were used to investigate the surface and inner structures of the blends. Results showed that ρs and ρv of PEW‐g‐AAS/PP blends dropped significantly (four to seven orders of magnitudes) above a critical addition at 10%, where an electrostatic dissipative network formed; PPW‐g‐AAS revealed an inferior antistatic performance than PEW‐g‐AAS due to its better compatibility and smaller content of dispersed phase in the matrix. Furthermore, the antistatic blends treated in 80°C water, 80°C air, and room temperature were investigated, and the results were interpreted from surface energy. Moreover, the addition of antistatic agent had little impact on tensile strength of the PP matrix. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Preparation and some properties of stereocomplex‐type poly(lactic acid)/layered silicate nanocomposites
Authors: Furuhashi Yukiko , Morioka Kousuke , Tamegai Hideyuki , Yoshie Naoko 
Published: May 2012

AbstractStereocomplex‐type poly(lactic acid)‐ [PLA]‐ based blends were prepared by solution casting of equimolar PLLA/PDLA with different amounts of organo‐modified montmorillonite. The homocrystallization and stereocomplexation of PLAs were enhanced by annealing of the blends. The stereocomplexation of PLAs, intercalation of the polymer chains between the silicates layers, and morphological structure of the filled PLAs were analyzed by wide‐angle X‐ray diffraction and transmission electron microscope. Thermogravimetric analyses (TGA), differential scanning calorimetry (DSC), and tensile test were performed to study the thermal and mechanical properties of the blends. The homo‐ and stereocomplex crystallization of neat PLLA/PDLA were enhanced by annealing. The effect of annealing on the crystallization was emphasized by the addition of clay. With this structural change, thermal stabilities properties were also improved by the addition of clay. The silicate layers of the clay were slightly stacked but intercalated and distributed in the PLA‐matrix. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Preparation and characterization of new flame retardant polyurethane composite and nanocomposite
Authors: Aslzadeh Mohammad M. , Abdouss Majid , Sadeghi Gity M. M. 
Published: May 2012

AbstractIn this work, a new flame retardant additive [2‐phenyl‐1,3,2 oxazaphospholidine 2‐oxide (POPO)] containing phosphorus and nitrogen is synthesized using phenyl phosphonic dichloride, ethanol amine, and copper (II) chloride, as catalyst. POPO is characterized by 1H‐NMR, 13C‐NMR, and 31P‐NMR and used as additive in polyurethane composites. Moreover, two commercial flame retardant additives [tricalcium diphosphate and hexabromocyclododecane (HBCD)] as well as nanoclay are used to compare flame retardancy of the synthesized additive. Limited oxygen index (LOI) and time burning (flammability test) of polyurethane composites and nanocomposites are evaluated. The results of the LOI test demonstrate that POPO is an excellent flame retardant additive and can be used to improve flame retardancy of polyurethane composites. In addition, increasing the additive content leads to an improvement of the flame retardancy of the samples. The LOI results show, however, that POPO is a good flame retardant, but the high synthesis cost of this flame retardant is a major disadvantage. Thermogravimetric analysis results show that using POPO in polyurethane matrices leads to low thermal stability and high char residue. Moreover, the nanocomposite has better thermal stability than the other samples. Scanning electron microscope micrographs have been used to evaluate the char residue of the samples. These micrographs indicate that POPO is an intumescent flame retardant and HBCD follows a nonintumescent mechanism. Exfoliated/intercalated structures have been shown for nanocomposites by transmission electron microscope. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Comparative study of maleated and glycidyl methacrylate functionalized terpolymers as compatibilizers for low‐density polyethylene–wood flour composites
Authors: Altun Yasemin , Doğan Mehmet , Bayramlı Erdal 
Published: May 2012

AbstractTwo types of terpolymers, maleic anhydride (MA) and glycidyl methacrylate (GMA) functionalized, are used as compatibilizer in low‐density polyethylene–wood flour composites. The type and amount of compatibilizer on the tensile, impact, morphological, and water absorption properties of composites are investigated. The effect of preimpregnation with a compatibilizer solution is also studied. The MA functionalized compatibilizer increases the mechanical properties of composites, when it is used either directly or with preimpregnation. GMA functionalized compatibilizer is not as effective as MA functionalized compatibilizer giving rise to small improvements in properties. An important point is doubling of the modulus with MA preimpregnated compatibilizer. With both compatibilizers the water absorption value of composites are reduced and the preimpregnation with both compatibilizers do not change the total amount of absorbed water with respect to the non‐preimpregnated ones. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Preparation and performance of high refractive index silicone resin‐type materials for the packaging of light‐emitting diodes
Authors: Yang Xiongfa , Shao Qian , Yang Linlin , Zhu Xiaobiao , Hua Xilin , Zheng Qunliang , Song Guangxin , Lai Guoqiao 
Published: May 2012

AbstractA novel high refractive index and highly transparent silicone resin‐type material for the packaging of high‐power light‐emitting diodes (LEDs) is introduced, which was synthesized by hydrosilylation of vinyl end‐capped methylphenyl silicone resin and methylphenyl hydrosilicone oil catalyzed by Karstedt's catalyst. The vinyl end‐capped methylphenyl silicone resins were prepared by hydrolysis−polycondensation method from methylphenyl diethoxysilane (MePhSi(OEt)2), phenyl triethoxysilane (PhSi(OEt)3), and vinyl dimethylethoxy silane (Me2ViSiOEt) in toluene/water mixture catalyzed by cation‐exchange resin. The vinyl end‐capped methylphenyl silicone resins were characterized by 1H‐NMR and Fourier‐transform infrared. The performances of the cured silicone resin‐type materials for LED packaging have been examined in detail. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Y:BaZrO3 Perovskite Compounds I: DFT Study on the Unprotonated and Protonated Local Structures
Authors: Cammarata Antonio , Ordejón Pablo , Emanuele Antonio , Duca Dario 
Published: May 2012

AbstractY‐doped BaZrO3 derivatives were studied by density functional theory (DFT) to investigate the local arrangements of the octahedral sites in Pmm cubic frameworks. Single‐ and double substitution of zirconium by yttrium were considered, including in the presence of a nearby oxygen vacancy. Although the structural symmetry of undoped barium zirconate was not modified after yttrium doping, the presence of yttrium induced several differences in the oxygen sites around it, according to the local geometrical arrangement of yttrium in the host matrix. As an example, the differences between such oxygen sites were shown in the presence of a proton. In this case, different stabilization energies characterized the protonated fragments. Only in those structures, in which two yttrium atoms were neighbors (i.e., formed Y‐O‐Y moieties), were the relative energy differences between the corresponding proton stable sites in agreement with the order of magnitude of the experimental proton‐hopping activation energies. The distribution of such energy differences suggested a grouping of the oxygen atoms into three sets, which had peculiar structural features that weren′t easily deducible from their topologies. The existence of proton traps was also discussed on the basis of the energy‐difference distributions.
Exponential H∞ Filtering for Discrete‐Time Switched State‐Delay Systems Under Asynchronous Switching
Authors: Zheng Yan , Feng Gang , Qiu Jianbin 
Published: May 2012

AbstractThe exponential H∞ filtering problem of discrete‐time switched state‐delay systems under asynchronous switching is considered in this paper. The objective is to design a full‐order or reduced‐order switched filter guaranteeing the exponential stability with the weighted H∞ performance of the filtering error system. A sufficient condition for the exponential stability with the weighted H∞ performance of the filtering error system is provided based on delay‐dependent multiple Lyapunov‐Krasovskii functionals. The gains of the filter can be obtained by solving a set of linear matrix inequalities. A numerical example is presented to demonstrate the effectiveness of the developed results.
Bounded Consensus Algorithms for Multi‐Agent Systems in Directed Networks
Authors: Du Haibo , Li Shihua , Ding Shihong 
Published: May 2012

AbstractIn this paper, the consensus problem is investigated via bounded controls for the multi‐agent systems with or without communication. Based on the nested saturation method, the saturated control laws are designed to solve the consensus problem. Under the designed saturated control laws, the transient performance of the closed‐loop system can be improved by tuning the saturation level. First of all, asymptotical consensus algorithms with bounded control inputs are proposed for the multi‐agent systems with or without communication delays. Under these consensus algorithms, the states’ consensus can be achieved asymptotically. Then, based on a kind of novel nonlinear saturation functions, bounded finite‐time consensus algorithms are further developed. It is shown that the states’ consensus can be achieved in finite time. Finally, two examples are given to verify the efficiency of the proposed methods.
Voluntary Disclosures of Emissions by US Firms
Authors: Stanny Elizabeth 
Published: May 2012

ABSTRACTThis paper examines voluntary disclosures about greenhouse gas emissions by the US S&P 500 firms to the Carbon Disclosure Project (CDP). Trends in three disclosures (answering the questionnaire, disclosing emissions and disclosing accounting methodology for emissions) are examined from 2006 to 2008. The frequencies of all three disclosures increased over this period. The finding that many firms answer the questionnaire, but do not disclose their emission amounts or how they account for them, is consistent with a prediction from the legitimacy theory literature that firms will disclose the minimum to avoid scrutiny. Disclosure patterns are routine since previous disclosures are the most significant variable in explaining subsequent ones. The research contributes to the understanding of emission disclosures, in particular, and voluntary disclosures, in general, by highlighting the importance of considering previous disclosures in understanding subsequent ones. Copyright © 2012 John Wiley & Sons, Ltd and ERP Environment
Using TSPi and PBL to support software engineering education in an upper‐level undergraduate course
Authors: Garcia I. A. , Pacheco C. L. 
Published: May 2012

ABSTRACTIn recent years, software engineering education has rapidly changed to incorporate more realistic ways of learning. More frequently the software industry requires more skilled and qualified staff; however at the university level students are young, inexperienced, and relatively homogeneous in background and abilities. This article describes an approach that integrates a student teamwork methodology (TSPi) and project‐based learning (PBL) to improve software project managerial skills in undergraduate students. As complementary support, a computational tool, the Teamwork Platform for Software Engineering Education, has been developed to establish an interactive software engineering course with local software industry collaboration. Experimental results show that a set of software metrics was defined to demonstrate performance improvement of 45 students following our approach.© 2012 Wiley Periodicals, Inc. Comput Appl Eng Educ 22:736–749, 2014; View this article online at wileyonlinelibrary.com/journal/cae; DOI 10.1002/cae.21566
Providing Support in Favor of the Existence of a PdII/PdIV Catalytic Cycle in a Heck‐Type Reaction
Authors: Juliá‐Hernández Francisco , Arcas Aurelia , Vicente José 
Published: May 2012

AbstractThe complex [Pd(O,N,C‐L)(OAc)], in which L is a monoanionic pincer ligand derived from 2,6‐diacetylpyridine, reacts with 2‐iodobenzoic acid at room temperature to afford the very stable pair of PdIV complexes (OC‐6‐54)‐ and (OC‐6‐26)‐[Pd(O,N,C‐L)(O,C‐C6H4CO2‐2)I] (1.5:1 molar ratio, at −55 °C). These complexes and the PdII species [Pd(O,N,C‐L)(OX)] and [Pd(O,N,C‐L′)(NCMe)]ClO4, (X=MeC(O) or ClO3, L′=another monoanionic pincer ligand derived from 2,6‐diacetylpyridine), are precatalysts for the arylation of CH2CHR (RCO2Me, CO2Et, Ph) using IC6H4CO2H‐2 and AgClO4. These catalytic reactions have been studied and a tentative mechanism is proposed. The presence of two PdIV complexes was detected by ESI(+)‐MS during the catalytic process. All the data obtained strongly support a PdII/PdIV catalytic cycle.
SnS‐Quantum Dot Solar Cells Using Novel TiC Counter Electrode and Organic Redox Couples
Authors: Guo Wei , Shen Yihua , Wu Mingxing , Wang Liang , Wang Linlin , Ma Tingli 
Published: May 2012

AbstractLow‐cost quantum‐dot sensitized solar cells (QDSSCs) were fabricated by using the earth‐abundant element SnS quantum dot, novel TiC counter electrodes, and the organic disulfide/thiolate (T2/T−) redox couple, and reached an efficiency of 1.03 %. QDSSCs based on I−/I3−, T2/T−, and S2−/Sx2− redox couples were assembled to study the role of the redox couples in the regeneration of sensitizers. Charge‐extraction results reveal the reasons for the difference in JSC in three QDSSCs based on I−/I3−, T2/T−, and S2−/Sx2− redox couples. The catalytic selectivity of TiC and Pt towards T2/T− and I−/I3− redox couples was investigated using Tafel polarization and electrochemical impedance analysis. These results indicated that Pt and TiC show a similar catalytic selectivity for I−/I3−. However, TiC possesses better catalytic activity for T2/T− than for I−/I3−. These results indicate the great potential of transition metal carbide materials and organic redox couples used in QDSSCs.
Predicting the physicochemical profile of diastereoisomeric histidine‐containing dipeptides by property space analysis
Authors: Vistoli Giulio , Straniero Valentina , Pedretti Alessandro , Fumagalli Laura , Bolchi Cristiano , Pallavicini Marco , Valoti Ermanno , Testa Bernard 
Published: May 2012

AbstractObjectivesThis study aimed at measuring the lipophilicity and ionization constants of diastereoisomeric dipeptides, interpreting them in terms of conformational behavior, and developing statistical models to predict them.MethodsA series of 20 dipeptides of general structure NH2‐L‐X‐(L or D)‐His‐OMe was designed and synthetized. Their experimental ionization constants (pK1, pK2 and pK3) and lipophilicity parameters (log PN and log D7.4) were measured by potentiometry. Molecular modeling in three media (vacuum, water, and chloroform) was used to explore and sample their conformational space, and for each stored conformer to calculate their radius of gyration, virtual log P (preferably written as log PMLP, meaning obtained by the molecular lipophilicity potential (MLP) method) and polar surface area (PSA). Means and ranges were calculated for these properties, as was their sensitivity (i.e., the ratio between property range and number of rotatable bonds).ResultsMarked differences between diastereoisomers were seen in their experimental ionization constants and lipophilicity parameters. These differences are explained by molecular flexibility, configuration‐dependent differences in intramolecular interactions, and accessibility of functional groups. Multiple linear equations correlated experimental lipophilicity parameters and ionization constants with PSA range and other calculated parameters.ConclusionThis study documents the differences in lipophilicity and ionization constants between diastereoisomeric dipeptides. Such configuration‐dependent differences are shown to depend markedly on differences in conformational behavior and to be amenable to multiple linear regression. Chirality 24:566–576, 2012. © 2012 Wiley Periodicals, Inc.
Variations in pain management outcomes among palliative care centers and the impact of organizational factors
Authors: Shin Dong Wook , Hwang Seung Sik , Oh Juhwan , Kim Jung Hoe , Park Jong Hyock , Cho Juhee , Cho Belong , Jung Kee Taig , Park Eun‐Cheol 
Published: May 2012

AbstractBACKGROUND:The assessment of pain management outcomes is important for the quality assurance of palliative care. The objective of this study was to determine whether there are significant variations in pain management outcomes among palliative care centers and whether they are affected by organizational factors.METHODS:Data used in this investigation were from the 2009 Korean Terminal Cancer Patient Information System and administrative records of the 34 inpatient palliative care centers designated by the Korean Ministry of Health and Welfare in 2009. Self‐reported pain scores (range, from 0 to 10) at admission and 1 week after admission were prospectively collected. Multilevel mixed‐effect regression models were used to analyze the variations and the impact of organizational‐level factors on 2 pain management outcomes (ie, reduction in average pain score and achievement of adequate pain control at 1 week after admission).RESULTS:In total, 1711 patients with terminal cancer were included in the analyses. The mean reduction in the pain score was 0.69 to 1.91 after 1 week, and most patients (82.8%) achieved adequate pain control. There were significant variations in pain management outcomes among palliative care centers. Higher composite scores for human resources adequacy were associated significantly with a greater reduction in pain score (β, 0.11; 95% confidence interval, 0.01‐0.21), and achievement of adequate pain control (adjusted odds ratio, 1.26; 95% confidence interval, 1.10‐1.45).CONCLUSIONS:There were significant variations in pain management outcomes among inpatient palliative care centers, and they were affected by organizational factors, such as human resources adequacy. Cancer 2011. © 2012 American Cancer Society.
Stereotactic body radiation therapy for inoperable hepatocellular carcinoma as a local salvage treatment after incomplete transarterial chemoembolization
Authors: Kang Jin‐Kyu , Kim Mi‐Sook , Cho Chul Koo , Yang Kwang Mo , Yoo Hyung Jun , Kim Jin Ho , Bae Sun Hyun , Jung Da Hoon , Kim, Kum Bae , Lee Dong Han , Han Chul Ju , Kim Jin , Park Su Cheol , Kim Young Han 
Published: May 2012

AbstractBACKGROUND:The objective of this study was to evaluate the efficacy and safety of stereotactic body radiation therapy (SBRT) as a local salvage treatment after incomplete transarterial chemoembolization (TACE) for inoperable hepatocellular carcinoma (HCC).METHODS:The main eligibility criteria were a greatest tumor dimension (LD sum) <10 cm, inoperable HCC, and incomplete response after TACE. Prescribed SBRT doses were up to 60 gray (Gy) in 3 fractions, but doses were reduced until normal tissue constraints were allowed.RESULTS:Between May 2008 and February 2011, 50 patients were enrolled in this phase 2 trial, of which 47 patients were evaluable. Forty‐one patients had Child‐Pugh class A disease (A5/A6 were 32/9), 6 patients had class B7 disease, and 5 patients had portal vein tumor thrombosis. All patients underwent TACE 1 to 5 times before SBRT. SBRT doses ranged from 42 to 60 Gy in 3 fractions (median dose, 57 Gy), and the median LD sum was 29 mm (range, 13‐78 mm). Eighteen patients (38.3%) achieved complete remission within 6 months of completing of SBRT, and 18 patients (38.3%) had a partial response. The 2‐year local control rate was 94.6%, the overall survival rate was 68.7%, and the progression‐free survival rate was 33.8%. Three patients (6.4%) experienced grade 3 gastrointestinal toxicity, and 2 patients (4.3%) experienced grade 4 gastric ulcer perforation.CONCLUSIONS:This trial demonstrated that SBRT after incomplete TACE for inoperable HCC achieves promising rates of response and local control. On the basis of these study results, a modified, multi‐institutional, phase 2 trial to reduce gastrointestinal toxicity is recommended. Cancer 2012. © 2012 American Cancer Society.
Head and neck carcinoma in the United States
Authors: Ang K. Kian , Chen Amy , Curran Walter J. , Garden Adam S. , Harari Paul M. , Murphy Barbara A. , Wong Stuart J. , Bellm Lisa A. , Schwartz Marc , Newman Jason , Adkins Douglas , Hayes D. Neil , Parvathaneni Upendra , Brachman David , Ghabach Bassam , Schneider Charles J. , Greenberg Michael , Anné Pramila R. 
Published: May 2012

AbstractBACKGROUND:Detailed information about how patients with head and neck carcinoma (HNC) are treated across practice settings does not exist. The authors conducted a prospective, observational study to examine the patterns of care for a series of patients with newly diagnosed HNC in the United States and to test 2 hypotheses: 1) There is no difference in the pattern of care between community and academic settings; and 2) the results of major randomized clinical trials will change the pattern of care in both practice settings within 1 year of publication in peer‐reviewed journals.METHODS:Patients aged ≥18 years were enrolled in the Longitudinal Oncology Registry of Head and Neck Carcinoma (LORHAN) after providing written informed consent if they had a confirmed diagnosis of new HNC and were scheduled to receive treatment other than surgery alone.RESULTS:Between 2005 and 2010, 100 centers enrolled 4243 patients, including 2612 patients (62%) from academic investigators and 1631 patients (38%) from community centers. Initial treatments were radiation with concurrent chemotherapy (30%) or cetuximab (9%), adjuvant radiotherapy (21%), induction chemotherapy (16%), and other (24%). Intensity modulated radiation therapy was the dominant radiation technique (84%). Single‐agent cisplatin was prescribed in nearly half of patients and more often in academic centers (53% vs 43% of patients; P < .0001). Single‐agent cetuximab was the next most common drug used (19%) and was prescribed more frequently in community settings (24% vs 17%; P = .0001). The data rejected the 2 prospective hypotheses.CONCLUSIONS:LORHAN documented differences in patient characteristics and treatments between community and academic settings for a large series of patients in the United States. Cancer 2012. © 2012 American Cancer Society.