bluuebunny/crossref_metadata_2025_split huggingface dataset:
Microstructural, mechanical, and thermal characteristics of recycled cellulose fiber‐halloysite‐epoxy hybrid nanocomposites
Authors: Alamri H. , Low I. M. 
Published: February 2012

AbstractEpoxy hybrid‐nanocomposites reinforced with recycled cellulose fibers (RCF) and halloysite nanotubes (HNTs) have been fabricated and investigated. The dispersion of HNTs was studied by synchrotron radiation diffraction (SRD) and transmission electron microscopy (TEM). The influences of RCF/HNTs dispersion on the mechanical properties and thermal properties of these composites have been characterized in terms of flexural strength, flexural modulus, fracture toughness, impact toughness, impact strength, and thermogravimetric analysis. The fracture surface morphology and toughness mechanisms were investigated by SEM. Results indicated that mechanical properties increased because of the addition of HNTs into the epoxy matrix. Flexural strength, flexural modulus, fracture toughness, and impact toughness increased by 20.8, 72.8, 56.5, and 25.0%, respectively, at 1 wt% HNTs load. The presence of RCF dramatically enhanced flexural strength, fracture toughness, impact strength, and impact toughness of the composites by 160%, 350%, 444%, and 263%, respectively. However, adding HNTs to RCF/epoxy showed only slight enhancements in flexural strength and fracture toughness. The inclusion of 5 wt% HNTs into RCF/epoxy ecocomposites increased the impact toughness by 27.6%. The presence of either HNTs or RCF accelerated the thermal degradation of neat epoxy. However, at high temperature, samples reinforced with RCF and HNTs displayed better thermal stability with increased char residue than neat resin. POLYM. COMPOS. 2012. © 2012 Society of Plastics Engineers
Poly(urethane‐co‐vinyl imidazole)/graphene nanocomposites
Authors: Cai Zhixin , Liu Li , Zheng Zhen , Wang Xinling 
Published: February 2012

AbstractPoly(urethane‐co‐vinyl imidazole) (PUVI)/graphene nanocomposites were facilely prepared by a kind of noncovalent way. Herein, the 1‐vinylimidazole acted as dispersion agent as well as monomer, graphene was uniformly dispersed in the copolymer matrix without obviously agglomeration. A significant enhancement of mechanical and thermal properties of the PUVI/graphene nanocomposites were obtained at low graphene loading; specifically, a 147% improvement of tensile strength, a nearly 10 times increase of elastic modulus and a 12°C enhancement of thermal decomposition temperature were achieved at a graphene loading of 1.5 wt%. Moreover, the volume resistivity of the PUVI/graphene nanocomposites decreased by an order of magnitude after adding 0.5 wt% graphene, demonstrating an obvious change in the electrical property of the nanocomposites prepared. POLYM. COMPOS. 2012. © 2012 Society of Plastics Engineers
Ethylene‐vinyl acetate copolymer/multiwalled carbon nanotube/organoclay nanocomposites
Authors: Seol Sung‐Mok , Kim Gue‐Hyun 
Published: February 2012

AbstractEthylene‐vinyl acetate copolymer (EVA) was melt‐mixed with multiwalled carbon nanotubes (MWCNTs) and organoclays, and the effects of simultaneous use of organoclays and MWCNTs on the surface resistivity and tensile properties of EVA nanocomposites were investigated. The surface resistivity of EVA/MWCNT nanocomposite with 1 phr of MWCNT is out of our measurement range (above 1012 Ω/square). With increasing content of organoclay from 0 to 3 phr, the surface resistivity of the EVA/MWCNT/organoclay nanocomposites with 1 phr MWCNT remains out of our measurement range. However, the surface resistivity of the nanocomposite decreases to 106 Ω/square with addition of 5 phr organoclay. The tensile properties of EVA/MWCNT/organoclay nanocomposites with 1 phr MWCNT and 5 phr organocaly are similar to those of EVA/MWCNT nanocomposites with 5 phr MWCNT except tensile modulus. POLYM. COMPOS. 2012. © 2012 Society of Plastics Engineers
Advanced PERC and PERL production cells with 20.3% record efficiency for standard commercial p‐type silicon wafers
Authors: Wang Zhenjiao , Han Peiyu , Lu Hongyan , Qian Hongqiang , Chen Liping , Meng Qinglei , Tang Ning , Gao Feng , Jiang Yongfei , Wu Jiaqi , Wu Wenjuan , Zhu Haidong , Ji Jingjia , Shi Zhengrong , Sugianto Adeline , Mai Ly , Hallam Brett , Wenham Stuart 
Published: February 2012

ABSTRACTFollowing intensive research and development, Suntech Power has successfully commercialised its Pluto technology with 0.5 GW annual production capacity, delivering up to 10% performance advantage over conventional screen‐printed cells. The next generation of Pluto involves the development of improved rear surface design based on the design features of passivated emitter and rear locally diffused cells. Cells with an average efficiency over 20% were fabricated on 155 cm2 commercial‐grade p‐type wafers using mass‐manufacturing processes and equipment, with the highest single‐cell efficiency independently confirmed at 20.3%. This is believed to be a record efficiency for this wafer type. Further optimisation work on contact pattern and rear surface passivation suggests the potential for further efficiency increase approaching 23%. Copyright © 2012 John Wiley & Sons, Ltd.
Overview of an effective‐medium approach to the reflection and refraction of light at a turbid colloidal half‐space
Authors: Gutiérrez‐Reyes Edahí , García‐Valenzuela Augusto , Barrera Rubén G. 
Published: February 2012

AbstractIt has been recently shown that the effective electromagnetic bulk response of a dilute colloidal system, composed by a large collection of identical big spheres, located at random, is spatially dispersive (non‐local). Here, we extend this effective‐medium approach to the calculation of the reflection and transmission amplitudes of the same system but with a flat interface. We use an integral‐equation approach for the calculation of the average electric field. The integral equation is solved within the effective‐field approximation, by proposing a plane‐wave solution with effective parameters that are calculated by solving a set of consistency equations. We obtain explicit expressions for the transmission and reflection amplitudes as a function of the filling fraction, the radius of the inclusions and the angle of incidence. We show and discuss numerical results for a system of silver particles.
Stationary high‐field domains as tools to measure field‐dependent carrier densities and mobilities in CdS and work functions of blocking contacts
Authors: Böer Karl W. 
Published: February 2012

AbstractIt is shown that stationary high‐field domains that occur in the range of negative differential conductivity, can be used to clearly identify field‐quenched states in CdS. These are distinguished as cathode‐ and anode‐adjacent domains and permit an unambiguous determination of electron density and mobility as function of the electric field. The anode‐adjacent domain permits additional insight into the high‐field properties of CdS in a field range that is now stabilized in the pre‐breakdown range. Here one finds direct evidence, by using the spectral distribution of the photoconductivity within the domain, of inverting the CdS to p‐type either by more complete quenching or by hole injection from the anode. Both types of stationary domains are determined by the work function of blocking contacts and thereby permit a closer analysis of the contact/CdS interface by shifting the space charge region away from the cathode to the bulk‐side end of the domain. This allows a more precise determination of the dependence of the work function on the photoconductivity of the adjacent CdS. The field‐of‐direction (phase portrait) analysis of the time‐independent transport and Poisson equations allows a simple classification of the two types of stationary high‐field domains relating to the two singular points in the decreasing branch of the current–voltage characteristic. This permits a transparent discussion of the field distribution of these domains that can be directly observed by the Franz–Keldysh effect. Herewith the transition between cathode‐ to anode‐adjacent domains as a function of the applied voltage can be directly followed.
Synthesis and first‐principles calculations of the structural and electronic properties of type‐I clathrates Sr8Ga16SnxGe30 − x
Authors: Li D. C. , Fang L. , Deng S. K. , Kang K. Y. , Wei W. H. , Ruan H. B. 
Published: February 2012

AbstractIn the present work we report on the synthesis of type‐I clathrates Sr8Ga16SnxGe30 − x (0 ≤ x ≤ 12). To find out how the substitution of Sn for Ge affects structural stability and electronic structure, the structural and electronic properties for Sr8Ga16SnxGe30 − x (0 ≤ x ≤ 30) have been investigated by a first‐principles method based on the density‐functional theory (DFT). We found that the lattice constants of Sr8Ga16SnxGe30 − x series increase with increasing Sn content, which is consistent with X‐ray diffraction (XRD) results. Calculations indicate that the substitution of Sn for Ge leads to the change of the bulk modulus and the decrease of stability of the structure. It is found that these alloys are all indirect‐gap semiconductors and the bandgap decreases from about 0.36 eV in Sr8Ga16Ge30 to about 0.03 eV in Sr8Ga16Sn30 with increasing Sn content. The decrease of the bandgap is attributed to the increase of the free space for the Sr guest motion, which is accompanied by the guest's low‐energy modes and larger anharmonicity. These mean that an increase in the ratio of Sn‐to‐Ge can not only control the electrical properties of the materials, but also may reduce their thermal conductivity, suggesting that cage‐size tuning is one of the useful means to obtain high‐performance thermoelectric (TE) materials.
Mastering crosscutting architectural decisions with aspects
Authors: Sant'Anna Claudio , Garcia Alessandro , Batista Thais , Rashid Awais 
Published: February 2012

SUMMARYWhen reflecting upon driving system requirements such as security and availability, software architects often face decisions that have a broadly scoped impact on the software architecture. These decisions are the core of the architecting process because they typically have implications intertwined in a multitude of architectural elements and across multiple views. Without a modular representation and management of those crucial choices, architects cannot properly communicate, assess and reason about their crosscutting effects. The result is a number of architectural breakdowns, such as misinformed architectural evaluation, time‐consuming trade‐off analysis and unmanageable traceability. This paper presents an architectural documentation approach in which aspects are exploited as a natural way to capture widely‐scoped design decisions in a modular fashion. The approach consists of a simple high‐level notation to describe crosscutting decisions, and a supplementary language that allows architects to formally define how such architectural decisions affect the final architectural decomposition according to different views. On the basis of two case studies, we have systematically assessed to what extent our approach: (i) supports the description of heterogeneous forms of crosscutting architecture decisions, (ii) improves the support for architecture modularity analysis, and (iii) enhances upstream and downstream traceability of crosscutting architectural decisions. Copyright © 2012 John Wiley & Sons, Ltd.
Phase 1, open-label study of MEDI-547 in patients with relapsed or refractory solid tumors
Authors: Annunziata Christina M. , Kohn Elise C. , LoRusso Patricia , Houston Nicole D. , Coleman Robert L. , Buzoianu Manuela , Robbie Gabriel , Lechleider Robert 
Published: February 2012

Summary
Background Targeting the cell-surface receptor EphA2, which is highly expressed in some solid tumors, is a novel approach for cancer therapy. We aimed to evaluate the safety profile, maximum tolerated dose (MTD), pharmacokinetics, and antitumor activity of MEDI-547, an antibody drug conjugate composed of the cytotoxic drug auristatin (toxin) linked to a human anti-EphA2 monoclonal antibody (1C1), in patients with solid tumors relapsed/refractory to standard therapy. Methods In this phase 1, open-label study with planned dose-escalation and dose-expansion cohorts, patients received a 1-h intravenous infusion of MEDI-547 (0.08 mg/kg) every 3 weeks. Results Six patients received 0.08 mg/kg; all discontinued treatment. Dose escalation was not pursued. The study was stopped before cohort 2 enrollment due to treatment-related bleeding and coagulation events (hemorrhage-related, n = 3; epistaxis, n = 2). Therefore, lower doses were not explored and an MTD could not be selected. The most frequently reported treatment-related adverse events (AEs) were increased liver enzymes, decreased hemoglobin, decreased appetite, and epistaxis. Three patients (50%) experienced treatment-related serious AEs, including conjunctival hemorrhage, pain (led to study drug discontinuation), liver disorder, and hemorrhage. Best response included progressive disease (n = 5; 83.3%) and stable disease (n = 1; 16.7%). Minimal or no dissociation of toxin from 1C1 conjugate occurred in the blood. Serum MEDI-547 concentrations decreased rapidly, ~70% by 3 days post-dose. No accumulation of MEDI-547 was observed at 0.08 mg/kg upon administration of a second dose 3 weeks following dose 1. Conclusions The safety profile of MEDI-547 does not support further clinical
investigation in patients with advanced solid tumors.
Thermal and Mechanical Characterization of Epoxy Resins (ELO and ESO) Cured with Anhydrides
Authors: Samper M. D. , Fombuena V. , Boronat T. , García‐Sanoguera D. , Balart R. 
Published: February 2012

AbstractIn this work we have developed polymeric materials from epoxidized vegetable oils in order to obtain materials with excellent mechanical properties for use as green matrix composites. Epoxidized soybean oil (ESO), epoxidized linseed oil (ELO) and different mixtures of the two oils were used to produce the polymers. Phthalic anhydride (17 mol%) and maleic anhydride (83 mol%) which has a eutectic reaction temperature of 48 °C were used as crosslinking agents while benzyl dimethyl amine (BDMA) and ethylene glycol were used as the catalyst and initiator, respectively. The results showed that samples 100ELO and 80ELO20ESO could be used as a matrix in green composites because they demonstrated good mechanical properties.
CONJUGACY CLASS SIZES OF CERTAIN DIRECT PRODUCTS
Authors: CASOLO CARLO , TOMBARI ELISA MARIA 
Published: February 2012

AbstractWe consider finite groups in which, for all primes p, the p-part of the length of any conjugacy class is trivial or fixed. We obtain a full description in the case in which for each prime divisor p of the order of the group there exists a noncentral conjugacy class of p-power size.
Electoral competition, factionalism, and persistent party dominance in Botswana
Authors: Poteete Amy R. 
Published: February 2012

ABSTRACTThe Botswana Democratic Party (BDP) has maintained a super-majority in the National Assembly for over forty years despite increasingly competitive elections. Several factors contribute to the BDP's continued legislative dominance, including features of the electoral system, fragmentation of the party system, and obstacles to strategic voting behaviour. Factional competition has played a particularly important role. Botswana's political institutions encourage factional competition, and factionalism interacts with the electoral system to hinder consolidation of the party system. Botswana's experience underlines the importance of internal party dynamics and their interaction with features of the electoral and party system in enabling the persistence of legislative dominance in competitive electoral systems.
Morality plays and money matters: towards a situated understanding of the politics of homosexuality in Uganda
Authors: Sadgrove Joanna , Vanderbeck Robert M. , Andersson Johan , Valentine Gill , Ward Kevin 
Published: February 2012

ABSTRACTSince the drafting of Uganda's anti-homosexuality bill in 2009, considerable attention has been paid both in Uganda and across the African continent to the political and social significance of homosexual behaviour and identity. However, current debates have not adequately explained how and why anti-homosexual rhetoric has been able to gain such popular purchase within Uganda. In order to move beyond reductive representations of an innate African homophobia, we argue that it is necessary to recognise the deep imbrication of sexuality, family life, procreation and material exchange in Uganda, as well as the ways in which elite actors (including government officials, the media and religious leaders) are able to manipulate social anxieties to further particular ends. We employ a discourse analysis of reporting in the state-owned newspaperNew Vision, first considering how the issue of homosexuality has been represented in relation to wider discourses regarding threats to public morality and national sovereignty. Then, through fieldwork undertaken in Uganda in 2009, we explore three key themes that offer deeper insights into the seeming resonance of this popular rhetoric about homosexuality: constructions of the family, the nature of societal morality, and understandings about reciprocity and material exchange in contemporary Ugandan society.
Cultural translation of mobile telephones: mediation of strained communication among Ethiopian married couples
Authors: Kenaw Setargew 
Published: February 2012

ABSTRACTPrimarily aiming to highlight and exemplify how a technology can be socially and culturally appropriated, this article draws attention to the role of mobile phone communication in straining relations between married couples on the basis of material from Ethiopia. The findings show that mobile phone-mediated interactions between spouses are filled with monitoring and controlling activities, expressed in such forms as checking call logs, text messages, making casual calls, and switching-off phones, leading to highly strained relations that may result in the marital relation as a whole falling apart. These findings show how a technology can actively shape or influence interactions, and reveal interactions that might otherwise be concealed.
The ecological role of native and introduced species in the diet of the pumaPuma concolorin southern Patagonia
Authors: Zanón Martínez Juan Ignacio , Travaini Alejandro , Zapata Sonia , Procopio Diego , Santillán Miguel Ángel 
Published: February 2012

AbstractThere is evidence for the ecological extinction of the native prey of the pumaPuma concolorin north-western Argentine Patagonia. In this study we examine whether this is also the case in southern Patagonia. From 2004 to 2007 we examined the puma’s diet in three protected areas and two sheep ranches in Santa Cruz province. A total of 282 puma scats were analysed. In two of the protected areas and in the ranches 60–74% of the puma’s diet was native prey. Prey species were primarily guanaco Lama guanicoe, followed by Patagonian mara Dolichotis patagonum, lesser rhea Pterocnemia pennata pennata, Patagonian pichi Zaedyus pichiy and Magellanic penguin Spheniscus magellanicus. In the third protected area the main prey was the European hareLepus europaeus. Our results show a clear difference in the diet of the puma in southern compared to north-western Patagonia. Large native herbivores (i.e. guanaco and lesser rhea) maintain their role as the main prey species for the puma in southern Patagonia. We suggest, therefore, that native prey could be restored to those areas of Argentine Patagonia, such as the north-west, where they are currently ecologically extinct. Facilitating native species recovery and/or restoration and applying more rigorous controls to prevent the introduction of potential alien prey species of the puma both, within and outside protected areas, needs to be evaluated as a regional strategy.
Water funds and payments for ecosystem services: practice learns from theory and theory can learn from practice
Authors: Goldman-Benner Rebecca L. , Benitez Silvia , Boucher Timothy , Calvache Alejandro , Daily Gretchen , Kareiva Peter , Kroeger Timm , Ramos Aurelio 
Published: February 2012

AbstractPayments for ecosystem services (PES) are emerging worldwide as important mechanisms to align investments in human and natural well-being. PES projects are often defined as voluntary transactions where well-defined environmental/ecosystem services (or land uses likely to secure those services) are bought by a minimum of one service buyer, from a minimum of one service provider, if and only if the service provider continuously secures service provision (conditionality). Further criteria of PES include limiting additional objectives and ensuring that payments reward behaviour that would otherwise not occur (additionality). Together these best practices for PES are increasingly accepted as the most efficient means to achieve desired outcomes and are guiding funding for PES projects. We used a series of water funds (watershed-oriented PES projects based on a trust fund model) to examine how theoretical best practices could inform and improve practice and also how theory could learn from practical efforts. We conclude that thoughtful consideration is required when evaluating the promise of a PES approach against a theoretical ideal. We found that requiring conditionality may limit the use of creative finance mechanisms such as trust funds that can provide long-term benefits for conservation and human well-being, and that requiring additionality can exclude benefits from social diffusion and result in the inefficient targeting of PES funds. Finally, public–private partnerships in water funds lead to multiple additional/side objectives but partnerships are likely to lower transaction costs and provide transparent, long-term landscape-scale watershed management.
Optimization design for a jumping leg robot based on generalized inertia ellipsoid
Authors: Yao Jianjun , Yang Qi , Gao Shuang , Hu Shenghai 
Published: February 2012

SUMMARYThe isotropy of the generalized inertia ellipsoid is an evaluation index that can measure dynamic performance of a robot. This has significance in motion planning and design of a jumping robot. The generalized inertia of a jumping robot is analyzed. The generalized inertia tensor and the generalized inertia ellipsoid (GIE) are derived from the kinetic energy of the robot mechanism. From the viewpoint of geometrical shape change of the GIE, nonlinear characteristics of a jumping robot are analyzed. With the goal of minimizing nonlinear effects during its movement, the mechanism parameters of a jumping robot are optimized by adopting isotropy of the generalized inertia ellipsoid as its objective function. Example results demonstrate the efficiency and validity of the proposed optimization method.
The representation theory of C*-algebras associated to groupoids
Authors: CLARK LISA ORLOFF , AN HUEF ASTRID 
Published: February 2012

AbstractLet E be a second-countable, locally compact, Hausdorff groupoid equipped with an action of such that G: = E/ is a principal groupoid with Haar system λ. The twisted groupoid C*-algebra C*(E; G, λ) is a quotient of the C*-algebra of E obtained by completing the space of -equivariant functions on E. We show that C*(E; G, λ) is postliminal if and only if the orbit space of G is T0 and that C*(E; G, λ) is liminal if and only if the orbit space is T1. We also show that C*(E; G, λ) has bounded trace if and only if G is integrable and that C*(E; G, λ) is a Fell algebra if and only if G is Cartan.Let be a second-countable, locally compact, Hausdorff groupoid with Haar system λ and continuously varying, abelian isotropy groups. Let be the isotropy groupoid and : = /. Using the results about twisted groupoid C*-algebras, we show that the C*-algebra C*(, λ) has bounded trace if and only if is integrable and that C*(, λ) is a Fell algebra if and only if is Cartan. We illustrate our theorems with examples of groupoids associated to directed graphs.