bluuebunny/crossref_metadata_2025_split huggingface dataset:
A High‐Performance Renewable Thermosetting Resin Derived from Eugenol
Authors: Harvey Benjamin G. , Sahagun Christopher M. , Guenthner Andrew J. , Groshens Thomas J. , Cambrea Lee R. , Reams Josiah T. , Mabry Joseph M. 
Published: April 2014

AbstractA renewable bisphenol, 4,4′‐(butane‐1,4‐diyl)bis(2‐methoxyphenol), was synthesized on a preparative scale by a solvent‐free, Ru‐catalyzed olefin metathesis coupling reaction of eugenol followed by hydrogenation. After purification, the bisphenol was converted to a new bis(cyanate) ester by standard techniques. The bisphenol and cyanate ester were characterized rigorously by NMR spectroscopy and single‐crystal X‐ray diffraction studies. After complete cure, the cyanate ester exhibited thermal stability in excess of 350 °C and a glass transition temperature (Tg) of 186 °C. As a result of the four‐carbon chain between the aromatic rings, the thermoset displayed a water uptake of only 1.8 % after a four day immersion in 85 °C water. The wet Tg of the material (167 °C) was only 19 °C lower than the dry Tg, and the material showed no significant degradation as a result of the water treatment. These results suggest that this resin is well suited for maritime environments and provide further evidence that full‐performance resins can be generated from sustainable feedstocks.
In Situ Thermally Cross‐linked Polyacrylonitrile as Binder for High‐Performance Silicon as Lithium Ion Battery Anode
Authors: Shen Lanyao , Shen Lian , Wang Zhaoxiang , Chen Liquan 
Published: April 2014

AbstractElectrode integrity and electric contact between particles and between particle and current collector are critical for electrochemical performance, especially for that of electrode materials with large volume change during cycling and with poor electric conductivity. We report on the in situ thermally cross‐linked polyacrylonitrile (PAN) as a binder for silicon‐based anodes of lithium‐ion batteries. The electrode delivers excellent cycle life and rate capability with a reversible capacity of about 1450 mA h g−1 even after 100 cycles. The improved electrochemical performance of such silicon electrodes is attributed to heat‐treatment‐induced cross‐linking and the formation of conjugated PAN. These findings open new avenues to explore other polymers for both anode and cathode electrodes of rechargeable batteries.
The Effects of Preparation Conditions for a BaNbO2N Photocatalyst on Its Physical Properties
Authors: Hisatomi Takashi , Katayama Chisato , Teramura Kentaro , Takata Tsuyoshi , Moriya Yosuke , Minegishi Tsutomu , Katayama Masao , Nishiyama Hiroshi , Yamada Taro , Domen Kazunari 
Published: April 2014

AbstractBaNbO2N is a semiconductor photocatalyst active for water oxidation under visible‐light irradiation up to λ=740 nm. It is important to understand the nitridation processes of precursor materials to form BaNbO2N to tune the physical properties and improve the photocatalytic activity. Comprehensive experiments and analyses of temperatures, durations, ammonia flow rates, and barium/niobium ratios in the precursor during the nitridation process reveals that faster ammonia flow rates and higher barium/niobium ratios in the precursors help to suppress reduction of pentavalent niobium ions in the nitridation products and that the use of a precursor prepared by a soft‐chemistry route allows the production of BaNbO2N at lower temperatures in shorter times than the use of physical mixtures of BaCO3 and Nb2O5 because the niobium species is dispersed among the barium species. BaNbO2N prepared by the soft‐chemistry route exhibits comparatively higher activity than that prepared from physical mixtures of BaCO3 and Nb2O5, probably because of lower nitridation temperatures, which suppress excessive dissociation of ammonia, and thereby reduce pentavalent niobium ions, and intimate interaction of niobium and barium sources, which lowers the densities of mid‐gap states associated with defects.
Non‐isolated single‐switch DC–DC converters with extended duty cycle for high step‐down voltage applications
Authors: Sabzali Ahmad J. , Ismail Esam H. , Al‐Saffar Mustafa A. , Behbehani Hussain M. 
Published: April 2014

SummarySeveral new topologies of single‐switch non‐isolated DC–DC converters with wide conversion gain and reduced semiconductor voltage stress are proposed in this paper. Most of the proposed topologies are derived from the conventional inverse of SEPIC (Zeta) converter. The proposed topologies can operate with larger switch duty cycles compared with the existing single switch topologies, hence, making them well suitable for high step‐down voltage conversion applications. With extended duty cycle, the current stress in the active power switch is reduced, leading to a significant improvement of the system losses. Moreover, the active power switch in some of the proposed topologies is utilized much better compared to the conventional Zeta and quadratic‐buck converters. The principle of operation, theoretical analysis, and comparison of circuit performances with other step‐down converters are discussed regarding voltage and current stress and switch silicon utilization. Finally, simulation and experimental results for a design example of a 50 W/5 V at 42‐V input voltage operating at 50 kHz will be provided to evaluate the performance of the proposed converters. Copyright © 2014 John Wiley & Sons, Ltd.
Using watershed‐scale hydrological models to predict the impacts of increasing urbanization on freshwater fish assemblages
Authors: Knouft Jason H. , Chu Ma. Librada 
Published: April 2014

AbstractNatural flow regimes are important predictors of variation in freshwater biodiversity, yet urbanization can significantly impact the volume and variability of water moving through a watershed. Moreover, there is limited quantitative understanding of spatial variation in the effects of urbanization on watershed hydrology and the impacts of this variation on aquatic species distributions and assemblage composition. We used a physically based watershed model (MIKE‐SHE), a hydrodynamic river model (MIKE‐11), and current landcover classifications to characterize flows at sites across the Big River watershed in eastern Missouri. Estimates of streamflow from the MIKE‐SHE model based on current landcover classifications were then used to predict variation in fish species richness at 44 sites across the watershed. We also quantified the potential effects of five urbanization scenarios on streamflows throughout the watershed and used flow estimates from the urbanization hydrological models to predict changes in fish species richness as urban areas increase. Responses varied among sites, with some sites predicted to increase in species richness whereas others are predicted to decrease in species richness. This mosaic of responses is likely due to the inconsistent impact of urbanization on streamflows throughout the watershed. Results also differed among taxonomic groups. The number of species of Cyprinidae (minnows) is generally expected to increase within sites across the watershed, whereas the number of species of Centrachidae (bass and sunfish) is expected to decrease. This differential shift in cyprinid and centrarchid richness is predicted to have a compensatory effect, with overall richness remaining, on average, relatively constant among sites. Copyright © 2014 John Wiley & Sons, Ltd.
Effects of temperature and time of freezing on lipid oxidation in anchovy (Engraulis encrasicholus) during frozen storage
Authors: Aydin Isın , Gokoglu Nalan 
Published: April 2014

The aim of this study was to determine the effects of temperature and time of freezing on lipid oxidation in anchovy during frozen storage. The fish were frozen at three different temperatures (−20, −40, and −80°C). During the freezing, temperature of the thermal center of fish was measured using a thermo couple and then time of freezing was calculated. Frozen fish were stored in a deep freezer at −18°C for 6 months. The highest freezing velocity and the shortest freezing time were observed for anchovies frozen at −80°C. Peroxide value (PV), thiobarbutiric acid (TBA), para‐anisidine (p‐Av), conjugated diene (CD), and free fatty acid (FFA) values were significantly affected by freezing temperature. Low freezing temperature resulted in low oxidation level. Oxidation levels significantly increased during the storage. The lowest values were determined in the samples frozen at −80°C. The best freezing temperature in terms of delaying of lipid oxidation was found to be −80°C.During frozen storage, lipid oxidation is an important issue for fatty fish, anchovy.
Effect of roasting conditions on the fat, tocopherol, and phytosterol content and antioxidant capacity of the lipid fraction from cocoa beans of different Theobroma cacao L. cultivars
Authors: Oracz Joanna , Nebesny Ewa , Żyżelewicz Dorota 
Published: April 2014

The effect of roasting conditions on the content of fat, tocopherol, and phytosterol and antioxidant capacity of the lipid fraction from cocoa beans of different Theobroma cacao cultivars was investigated. The raw cocoa beans were roasted at four different temperatures (ranging from 110 to 150°C) and three different air humidities (0.3 to 5.0%). The results of this study show that roasting affected significantly the photochemical composition and lipophilic antioxidant activity of cocoa beans. Roasting may lead to significant degradation of α‐tocopherol and phytosterols when compared to raw cocoa beans. This was not true in samples roasted at the lowest temperatures and evaluated humidity; these samples had a higher γ‐ and δ‐tocopherol content and antioxidant capacity compared to the raw cocoa beans and samples roasted at other conditions. The present study also revealed that the content of bioactive compounds and antioxidant activity of different Theobroma cacao L. cultivars vary markedly.Practical applications: Cocoa beans are the primary raw material used in the manufacture of chocolate products, which can be great source of health‐beneficial bioactive compounds such as tocopherols and phytosterols. The differences between varieties in the levels of these bioactive compounds revealed in this study show that it is possible to increase their content in cocoa derived products by choosing an appropriate cultivar. Thermal processing at relatively high temperature may lead to the degradation of tocopherols and phytosterols.Influence of roasting conditions on the tocopherols (A), phytosterols (B), and antioxidant capacity (C) of the lipid fraction from cocoa beans of different Theobroma cacao L. cultivars
Ambient sonic‐spray ionization mass spectrometry for rapid monitoring of secondary oxidation products in biodiesel
Authors: Pereira Gustavo G. , Alberici Rosana M. , Fernandes Gabriel D. , Cunha Ildenize B. S. , Eberlin Marcos N. , Dobarganes M. C. , Daroda Romeu J. , Barrera‐Arellano Daniel 
Published: April 2014

This paper proposes the use of easy ambient sonic‐spray ionization mass spectrometry (EASI‐MS) to detect markers of high‐level oxidation in biodiesel via a simple and rapid single‐shot analytical protocol. Soybean biodiesel was oxidized in Rancimat and then analyzed at different time periods by both EASI‐MS and traditional physicochemical methods. Major changes in the EASI(+)‐MS profile as well in the peroxide value, acidity, and kinematic viscosity were observed after the induction period (IP). Fatty acid methyl esters (FAME) and their respective hydroperoxides were primarily identified using EASI‐MS in fresh biodiesel and at the initial stages of oxidation. After the IP, EASI‐MS revealed the formation of dimers and low‐mass non‐volatile molecules, such as aldehydes, due to hydroperoxide breakdown. Both the dimers and aldehydes are attributed to secondary oxidation products. Therefore, EASI‐MS was found to provide a fast, direct, and accurate technique to identify markers in biodiesel with high‐level of oxidation.Practical applications: EASI‐MS is a useful technique to identify primary and secondary oxidation products formed in biodiesel in a single procedure that is rapid and does not require sample preparation. Therefore, EASI‐MS has potential applications in biodiesel routine analysis to screen samples with high‐levels of oxidation.EASI‐MS provides a fast, direct, and accurate technique to identify markers in biodiesel with high‐level of oxidation.
Retracted: High‐Performance Molybdenum Dioxide‐Based Anode for Dodecane‐Fueled Solid‐Oxide Fuel Cells (SOFCs)
Authors: Kwon Byeong W. , Hu Shuozhen , Marin‐Flores Oscar , Norton M. Grant , Kim Jinsoo , Scudiero Louis , Breit Joe , Ha Su 
Published: April 2014

AbstractFor the solid‐oxide fuel cells (SOFCs), nickel–yttrium‐stabilized zirconia (Ni–YSZ) cermet anodes operating with complex liquid hydrocarbon fuels display severe carbon formation on the Ni surface and sulfur poisoning. In this present study, we fabricate molybdenum dioxide (MoO2)‐based anodes with an optimum microporous structure that leads to a maximum power density over 3 W cm−2 at 750 °C under the direct feeding of n‐dodecane fuel mixture. The cell resisted the carbon (coke) formation for over 24 h of continuous cell testing and was also resistant to deactivation with 500 ppm of sulfur in the fuel stream.
Characterization of Toluene Insolubles from Low‐Temperature Coal Tar
Authors: Li Dong , Liu Xin , Sun Zhihui , Tian Panpan , Li Wenhong 
Published: April 2014

AbstractHydrogenation has been investigated in recent years as a potential method for upgrading low‐temperature coal tar (LCT). LCT contains toluene insolubles (TIs) that can cause process problems by plugging hydrotreater feed filters and catalyst beds. In this study, TIs are separated from LCT, and the composition and structure are studied by using elemental analysis, scanning electron microscopy (SEM), Fourier‐transform infrared spectrometry (FTIR), X‐ray diffraction analyses (XRD), X‐ray photoelectron spectroscopy (XPS), and other techniques. Microscopic observations reveal TI particles to be small approximately 50 % of the particles have a diameter of <3 μm. TIs contain a high proportion of inorganic material, for example, quartz, aluminosilicate, and calcium. Evidence for aliphatic and aromatic species is demonstrated by FTIR and XPS analysis. Although LCT contains many complex aromatic compounds, TIs exhibit a lower degree of aromaticity. Sulfate salts are the main form of sulfur element, and the greatest amounts of nitrogen occur in TIs as pyridinic nitrogen (N‐6) and oxidized nitrogen (N‐X) species.
Monitoring of Scoring Using the e‐rater® Automated Scoring System and Human Raters on a Writing Test
Authors: Wang Zhen , von Davier Alina A. 
Published: April 2014

AbstractThis article proposes and investigates several methodologies for monitoring the quality of constructed‐response (CR) scoring, both human and automated. There is an increased interest in the operational scoring of essays using both automated scoring and human raters. There is also evidence of rater effects—scoring severity and score inconsistency by human raters. Recently, automated scoring of CRs was successfully implemented with human scoring for operational programs (TOEFL® and GRE® tests); however, there is much that is not yet known about the performance of automated scoring systems. Hence, for quality assurance purposes, there is the need to provide a consistent and standardized approach to monitor the quality of the CR scoring over time and across programs. Monitoring the scoring results will help provide scores that are both fair and accurate for test takers and test users, enabling testing programs to detect and correct changes in the severity of scoring.
The Impact of Health Insurance on Health Outcomes and Spending of the Elderly: Evidence from China's New Cooperative Medical Scheme
Authors: Cheng Lingguo , Liu Hong , Zhang Ye , Shen Ke , Zeng Yi 
Published: April 2014

AbstractThis paper investigates the effects of China's New Cooperative Medical Scheme (NCMS) on health outcomes and healthcare expenditure of the elderly in rural China, using panel data from the 2005 and 2008 waves of the Chinese Longitudinal Healthy Longevity Survey. We employ a strategy that combines propensity score matching with a difference‐in‐differences approach to address selection bias. Results show that the NCMS has significantly improved the elderly enrollees' activities of daily living and cognitive function but has not led to better self‐assessed general health status. We find no significant effect of NCMS on mortality for the previously uninsured elderly in NCMS counties, although there is moderate evidence that it is associated with reduced mortality for the elderly enrollees. We also find that the elderly participants are more likely to get adequate medical services when sick, which provides a good explanation for the beneficial health effects of NCMS. However, there is no evidence that the NCMS has reduced their out‐of‐pocket spending. Furthermore, we also find that low‐income seniors benefit more from NCMS participation in terms of health outcomes and perceived access to health care, suggesting that the NCMS helps reduce health inequalities among the rural elderly. Copyright © 2014 John Wiley & Sons, Ltd.
Photochemically Controlled Molecular Machines with Sequential Logic Operation
Authors: Avellini Tommaso , Baroncini Massimo , Ragazzon Giulio , Silvi Serena , Venturi Margherita , Credi Alberto 
Published: April 2014

AbstractA molecular machine is an assembly of molecular components (i.e., a supramolecular structure) designed to perform specific mechanical movements in response to external stimuli. Biomolecular machines are essential for living organisms and are proven examples of the feasibility and utility of nanotechnology. Artificial molecular machines have been built in the laboratory and their use for smart materials and devices is the subject of much investigation. Here we discuss molecular machines based on rotaxane‐like species, whose operation depends both on the type and sequencing of stimuli. These systems have the potential to store information and when carefully designed, the interplay of thermodynamic and kinetic features of supramolecular assemblies can yield sequential behavior. The investigation of ‘intelligent’ molecules capable of recognizing a specific input code can introduce new concepts to the field of chemistry and stimulate research in the bottom‐up construction of nanodevices.
Recent Advances in Solution‐Processed White Organic Light‐Emitting Materials and Devices
Authors: Zhang Baohua , Liu Lihui , Xie Zhiyuan 
Published: April 2014

AbstractSolution‐processed white organic light‐emitting diodes (WOLEDs) have drawn great attention both in the academic and industrial research communities due to the potential application in low‐cost, large‐area, solid‐state lightings. Issues related to the device efficiencies are largely hampering progress in this field. Alongside the development of new materials and novel device architectures, distinct progress has been made for such white devices. In particular, the all‐phosphorescent light‐emitting strategy has been intensively developed in recent years, mainly focusing on a hostguest, doping‐system‐based, single‐active‐layer structure and a solution‐processed, multilayer device structure. Novel approaches, including white single polymers and excimer‐/exciplex‐based white devices, have also appeared as a promising choice and received great attention. As a prerequisite, the issue of the morphology of the emissive layer is also important and has an influence on the optoelectronic behavior of the device. Herein, major advances in solution‐processed WOLEDs based on polymers, dendrimers, or solution‐processed small molecules are summarized. Special attention is focused on the main progress in high‐efficiency, solution‐processed WOLEDs with the key strategies mentioned above and the morphology issue in these systems. The remaining challenges in pursuing the development of reliable and energy‐saving lighting devices are also discussed.
A Three‐Factor Product Construction for Mutually Orthogonal Latin Squares
Authors: Dukes Peter J. , Ling Alan C.H. 
Published: April 2014

AbstractIt is well known that mutually orthogonal latin squares, or MOLS, admit a (Kronecker) product construction. We show that, under mild conditions, “triple products” of MOLS can result in a gain of one square. In terms of transversal designs, the technique is to use a construction of Rolf Rees twice: once to obtain a coarse resolution of the blocks after one product, and next to reorganize classes and resolve the blocks of the second product. As consequences, we report a few improvements to the MOLS table and obtain a slight strengthening of the famous theorem of MacNeish.
Reactive Oxygen Species‐Dependent Nitric Oxide Production in Reciprocal Interactions of Glioma and Microglial Cells
Authors: Shen Shing‐Chuan , Wu Ming‐Shun , Lin Hui‐Yi , Yang Liang‐Yo , Chen Yi‐Hsuan , Chen Yen‐Chou 
Published: April 2014

AbstractConditioned mediums (CMs) from glioma cells U87, GBM‐8401, and C6 significantly induced iNOS protein and NO production by microglial cells BV‐2 but without altering the cell viability or cell‐cycle progression of BV2 microglia. Significant increases in intracellular peroxide by U87‐CM and C6‐CM were detected by a DCHF‐DA assay, and vitamin (Vit) C and N‐acetyl cysteine (NAC)‐reduced intracellular peroxide levels elicited by CMs lead to inhibition of iNOS/NO production The extracellular signal‐regulated kinase (ERK) inhibitor, U0126, and c‐Jun N‐terminal kinase (JNK) inhibitor, SP600125, suppressed U87‐CM‐ and C6‐CM‐induced iNOS/NO production by respectively blocking phosphorylated ERK (pERK) and JNK (pJNK) protein expressions stimulated by U87‐CM and C6‐CM. Increased migration of U87 and C6 glioma cells by a co‐culture with BV‐2 microglial cells or adding the nitric oxide (NO) donor, sodium nitroprusside (SNP) was observed, and that was blocked by adding an NO synthase (NOS) inhibitor, N‐nitro L‐arginine methyl ester (NAME). Contributions of ROS, pERK, and pJNK to the migration of glioma cells was further demonstrated in a transwell coculture system of U87 and C6 gliomas with BV‐2 microglial cells. Furthermore, expressions of tumor necrosis factor (TNF)‐α and monocyte chemoattractant protein (MCP)‐1 messenger (m)RNA in U87 and C6 cells were detected by an RT‐PCR, and TNF‐α and MCP‐1 induced iNOS protein expression in time‐ and concentration‐dependent manners. Neutralization of TNF‐α or MCP‐1 in U87‐CM and C6‐CM using a TNF‐α or MCP‐1 antibody inhibited iNOS protein expression, and increased intracellular peroxide by TNF‐α or MCP‐1 was identified in BV‐2 cells. The reciprocal activation of glioma cells and microglia via ROS‐dependent iNOS/NO elevation at least partially mediated by TNF‐α and MCP‐1 is elucidated. J. Cell. Physiol. 229: 2015–2026, 2014. © 2014 Wiley Periodicals, Inc.