bluuebunny/crossref_metadata_2025 huggingface dataset:
Methanol from TES global observations: retrieval algorithm and seasonal and spatial variability
Authors: Cady-Pereira K. E. , Shephard M. W. , Millet D. B. , Luo M. , Wells K. C. , Xiao Y. , Payne V. H. , Worden J.
Published: May 2012

Abstract. We present a detailed description of the TES methanol (CH3OH) retrieval algorithm, along with initial global results showing the seasonal and spatial distribution of methanol in the lower troposphere. The full development of the TES methanol retrieval is described, including microwindow selection, error analysis, and the utilization of a priori and initial guess information provided by the GEOS-Chem chemical transport model. Retrieval simulations and a sensitivity analysis using the developed retrieval strategy show that TES: (i) generally provides between 0.5 and 1.0 pieces of information, (ii) is sensitive in the lower troposphere with peak sensitivity typically occurring between ~900–700 hPa (~1–3 km) at a vertical resolution of ~5 km, (iii) has a limit of detectability between 0.5 and 1.0 ppbv Representative Volume Mixing Ratio (RVMR) depending on the atmospheric conditions, corresponding roughly to a profile with a maximum concentration of at least 1 to 2 ppbv, and (iv) in a simulation environment has a mean bias of 0.16 ppbv and a standard deviation of 0.34 ppbv. Applying the newly-derived TES retrieval globally and comparing the results with corresponding GEOS-Chem output, we find generally consistent large-scale patterns between the two. However, TES often reveals higher methanol concentrations than predicted in the Northern Hemisphere spring, summer and fall. In the Southern Hemisphere, the TES methanol observations indicate a model overestimate over the bulk of South America from December through July, and a model underestimate during the biomass burning season.
Aerosol profiling with the JenOptik ceilometer CHM15kx
Authors: Wiegner M. , Geiß A.
Published: May 2012

Abstract. Since a few years the number of active remote sensing systems is rapidly increasing when national weather services started to build up networks of ceilometers. As ceilometers can be considered as "simple" backscatter lidars it is obvious to investigate to which extent they can provide quantitative aerosol information. In this context the calibration of the ceilometer is the most crucial point: whereas previous studies primarily rely on the comparisons with co-incident sun photometer measurements and the Rayleigh calibration, we provide an absolute calibration of the ceilometer. The advantage of this approach is that backscatter profiles can be derived during daytime and nighttime, and even in cases when the signal-to-noise ratio of signals from the free troposphere is very low. Moreover, the retrieval can easily be automated. In this paper we consider the JenOptik CHM15kx-ceilometer. We discuss the methodology and the achievable accuracy and present a set of examples to highlight the wide range of applications, and the limitations. The achievable temporal resolution is of the order of a few minutes, the relative error of the particle backscatter coefficient is less than 10%. It is emphasized that the accuracy of extinction coefficients and – as a consequence – of the aerosol optical depth is limited due to the unknown lidar ratio. This is, however, an inherent problem of any backscatter lidar and not a special feature of the ceilometer.
Soil erosion and sediment delivery in a mountain catchment under scenarios of land use change using a spatially distributed numerical model
Authors: Alatorre L. C. , Beguería S. , Lana-Renault N. , Navas A. , García-Ruiz J. M.
Published: May 2012

Abstract. Soil erosion and sediment yield are strongly affected by land use/land cover (LULC). Spatially distributed erosion models are of great interest to assess the expected effect of LULC changes on soil erosion and sediment yield. However, they can only be applied if spatially distributed data is available for their calibration. In this study the soil erosion and sediment delivery model WATEM/SEDEM was applied to a small (2.84 km2) experimental catchment in the Central Spanish Pyrenees. Model calibration was performed based on a dataset of soil redistribution rates derived from point 137Cs inventories, allowing capture differences per land use in the main model parameters. Model calibration showed a good convergence to a global optimum in the parameter space, which was not possible to attain if only external (not spatially distributed) sediment yield data were available. Validation of the model results against seven years of recorded sediment yield at the catchment outlet was satisfactory. Two LULC scenarios were then modeled to reproduce land use at the beginning of the twentieth century and a hypothetic future scenario, and to compare the simulation results to the current LULC situation. The results show a reduction of about one order of magnitude in gross erosion (3180 to 350 Mg yr−1) and sediment delivery (11.2 to 1.2 Mg yr−1 ha−1) during the last decades as a result of the abandonment of traditional land uses (mostly agriculture) and subsequent vegetation recolonization. The simulation also allowed assessing differences in the sediment sources and sinks within the catchment.
Oscillating forcings and new regimes in the Lorenz system: a four-lobe attractor
Authors: Pelino V. , Maimone F. , Pasini A.
Published: May 2012

Abstract. It has been shown that forced Lorenz models generally maintain their two-lobe structure, just giving rise to changes in the occurrence of their regimes. Here, using the richness of a unified formalism for Kolmogorov-Lorenz systems, we show that introducing oscillating forcings can lead to the birth of new regimes and to a four-lobe attractor. Analogies within a climate dynamics framework are mentioned.
Endonasal Endoscopic Scalpel-Forceps Dacryocystorhinostomy vs Endocanalicular Diode Laser Dacryocystorhinostomy
Authors: Gras-Cabrerizo Juan R. , Montserrat-Gili Joan R. , León-Vintró Xavier , Lopez-Vilas Montse , Rodríguez-Álvarez Fernando , Bonafonte-Royo Sergio , Alegría Abelardo , Massegur-Solench Humbert
Published: May 2012

Purpose.

To compare the efficacy of endonasal endoscopic dacryocystorhinostomy and endocanalicular diode laser dacryocystorhinostomy.

Methods.

A total of 126 dacryocystorhinostomies were performed in 111 patients with epiphora. In 55% of cases (69/126) we performed an endonasal endoscopic dacryocystorhinostomy and in 45% (57/126) we carried out an endocanalicular dacryocystorhinostomy using diode laser. The mean age at diagnosis was 63 years. The mean age was higher in the endocanalicular group than in the endonasal endoscopic group: 64 versus 62 years. There were 25 men (23%) and 86 women (77%).

Results.

Successful results were achieved in 73% of patients (92/126). In the endonasal endoscopic group, 83% of patients (57/69) were symptom free compared to 62% of patients (35/57) in the laser diode group. A bicanalicular nasal silicone tube was left in place for a mean of 2.32 months in the endoscopic endonasal group and for 2.82 months in the laser diode group (p=0.164). Median time of recurrence after removal of the tube was 3.56 months (range 0–9.6): 2.84 months in the laser diode group and 4.87 months in the endonasal endoscopic group (p=0.069).

Conclusions.

The endonasal endoscopic approach achieved better results for nasolacrimal obstruction than the endocanalicular laser diode technique.
Humanist Controversies:
Authors: Mailloux Steven
Published: May 2012

This article discusses two twentieth-century examples of humanist controversies in order to demonstrate some rhetorical paths of thought involved in developing and securing rhetorical humanism within philosophy and rhetorical studies. The article begins with Martin Heidegger's antihumanist provocation and examines Ernesto Grassi's response in his revisionist interpretation of a nonmetaphysical Renaissance humanism. Next it takes up the post-Heideggerian moment of late twentieth-century postmodern critiques, including attacks on humanist foundationalism and essentialist notions of agency, and compares Grassi's defense of rhetorical humanism within Continental philosophy to Michael Leff's reinterpretation of Ciceronian humanism within communication studies. Both Grassi and Leff propose a rhetorical humanist alternative to Heidegger's and postmodernism's philosophical antihumanism. These two rhetoricians demonstrate an interpretive power and a rhetorical creativity that not only revitalize rhetorical humanism in the present age but also provide valuable resources for its extension into the future.
Effect of Chemical Treatment on Mechanical and Water-Sorption Properties Coconut Fiber-Unsaturated Polyester from Recycled PET
Authors: Munirah Abdullah Nurul , Ahmad Ishak
Published: May 2012

Coconut fibers were used as reinforcement for unsaturated polyester resin from recycled PET that has been prepared using glycolysis and polyesterification reaction. Various concentrations of alkali, silane, and silane on alkalized fiber were applied and the optimum concentration of treatments was determined. Morphological and mechanical properties of the composite have also been investigated to study the effect of fiber surface treatment. The influence of water uptake on the sorption characteristics of composites was studied via immersion in distilled water at room temperature. Surface treatment of coconut fiber caused a significant increase in the tensile properties with the optimum treatment of 0.5% silane on the 5% alkalized coconut fiber/polyester composites. For water absorption study, it was observed that the treated fiber composites showed lower water absorption properties in comparison to those of untreated fiber composites. SEM investigation showed that the surface modification of fiber has better fiber-matrix interaction. Thus, chemical treatments on the fiber improve fiber/matrix adhesion especially for silane on alkalized fiber treatment.
Magnetic Mn-Doped Ge Nanostructures
Authors: Xiu Faxian
Published: May 2012

With the seemly limit of scaling on CMOS microelectronics fast approaching, spintronics has received enormous attention as it promises next-generation nanometric magnetoelectronic devices; particularly, the electric field control of ferromagnetic transition in dilute magnetic semiconductor (DMS) systems offers the magnetoelectronic devices a potential for low power consumption and low variability. Special attention has been given to technologically important group IV semiconductor based DMSs, with a prominent position for Mn doped Ge. In this paper, we will first review the current theoretical understanding on the ferromagnetism in MnxGe1−x DMS, pointing out the possible physics models underlying the complicated ferromagnetic behavior of MnxGe1−x. Then we carry out detailed analysis of MnxGe1−x thin films and nanostructures grown by molecular beam epitaxy. We show that with zero and one dimension quantum structures, superior magnetic properties of MnxGe1−x compared with bulk films can be obtained. More importantly, with MnxGe1−x nanostructures, such as quantum dots, we demonstrate a field controlled ferromagnetism up to 100 K. Finally we provide a prospective of the future development of ferromagnetic field effect transistors and magnetic tunneling junctions/memories using dilute and metallic MnxGe1−x dots, respectively. We also point out the bottleneck problems in these fields and rendering possible solutions to realize practical spintronic devices.
The Matrix Linear Unilateral and Bilateral Equations with Two Variables over Commutative Rings
Authors: Dzhaliuk N. S. , Petrychkovych V. M.
Published: May 2012

The method of solving matrix linear equations and over commutative Bezout domains by means of standard form of a pair of matrices with respect to generalized equivalence is proposed. The formulas of general solutions of such equations are deduced. The criterions of uniqueness of particular solutions of such matrix equations are established.
On Certain Subclasses of Meromorphic Functions with Positive and Fixed Second Coefficients Involving the Liu-Srivastava Linear Operator
Authors: Magesh N. , Gatti N. B. , Mayilvaganan S.
Published: May 2012

We introduce and study a subclass ΣP(γ,k,λ,c) of meromorphic univalent functions defined by certain linear operator involving the generalized hypergeometric function. We obtain coefficient estimates, extreme points, growth and distortion inequalities, radii of meromorphic starlikeness, and convexity for the class ΣP(γ,k,λ,c) by fixing the second coefficient. Further, it is shown that the class ΣP(γ,k,λ) is closed under convex linear combination.
Boundedness and Compactness of the Mean Operator Matrix on Weighted Hardy Spaces
Authors: Yousefi Bahmann , Pazouki Ebrahim
Published: May 2012

We investigate the boundedness and the compactness of the
mean operator matrix acting on the weighted Hardy spaces.
Ser chuquicamatino: la construcción de la memoria de los desplazados de Chuquicamata en el norte de Chile, 2002-2007
Authors: Ibáñez Carvajal Daniela
Published: May 2012

Through the concepts of social memory, identity, and lieux de mémoire, this article analyzes how Chuquicamatinas, after their city was closed and community displaced, managed to reconstruct their identity and strengthen their memory in a place completely foreign to what they were used to. To do so, community members were asked their perceptions and opinions of this change and what it has meant to them. In their accounts, it is possible to see how, in periods of dispute and crisis, societies tend to become introspective and turn their attention to the essence of their identities. Questions about what happened and who they are raised a series of issues that they had ceased to be asked.
Hijos de víctimas del terrorismo de Estado. Justicia, identidad y memoria en el movimiento de derechos humanos en Argentina, 1995-2008
Authors: Cueto Rúa Santiago
Published: May 2012

This article analyzes hijos, the human rights organization comprised of children of the victims of state terrorism in Argentina. It examines some of the distinctive characteristics of this group, particularly with regard to the ruptures and continuities with the practices of the human rights movement. It analyzes how the group emerged, shaped its collective identity, formulated its demands for justice, and tells stories about the recent past.
Linking Crack Tip Morphology to Tear Toughness of Hot Rolled AA7050 Alloys Using X‐Ray Computed Tomography
Authors: Wu Xiaomin , Schlangen Erik , van der Zwaag Sybrand
Published: May 2012

A lab scale X‐ray tomography scanner is used to quantify the morphological details of crack tip regions of Kahn tear tested AA7050 aluminum samples subjected to different hot rolling conditions. The 3D crack tip images show distinctive differences in crack tip morphology (such as orientation and shape of the crack tip, bridging ligaments, crack opening distance, and plastic deformation around the crack tip) for samples with different fracture toughness. Quantification of the observations showed that the fracture toughness of AA7050 sample is directly related to the crack tip opening angle measured with computer tomography method.
Reforming insurance to support workers' rights to compensation
Authors: McCluskey Martha T.
Published: May 2012

The structure and regulation of the insurance system for financing workers' compensation affects the costs of workers' benefits. Using the example of Maine's insurance market restructuring in response to a crisis of the early 1990s, this commentary explores how changes in insurance regulation might better support the goals of workers' compensation. The commentary analyzes how insurance and its regulation should go beyond correct pricing of risks to questions of how to structure incentives for loss control to include workers' interests as well as the interests of employers and insurers. Am. J. Ind. Med. 55:545–559, 2012. © 2012 Wiley Periodicals, Inc.
Reexamining workers' compensation: A human rights perspective
Authors: Boden Leslie I.
Published: May 2012

Injured workers, particularly those with more severe injuries, have long experienced workers' compensation systems as stressful and demeaning, have found it difficult to obtain benefits, and, when able to obtain benefits, have found them inadequate. Moreover, the last two decades have seen a substantial erosion of the protections offered by workers' compensation. State after state has erected additional barriers to benefit receipt, making the workers' compensation experience even more difficult and degrading. These changes have been facilitated by a framing of the political debate focused on the free market paradigm, employer costs, and worker fraud and malingering. The articles in this special issue propose an alternate framework and analysis, a human rights approach, that values the dignity and economic security of injured workers and their families. Am. J. Ind. Med. 55:483–486, 2012. © 2012 Wiley Periodicals, Inc.
Synthesis of hydroxyl‐terminated poly(lactic acid) via polycondensation: An equation to predict molecular weight based on the reaction parameters
Authors: Izadi‐Vasafi Hossein , Mohamad Sadeghi Gity Mir , Garmabi Hamid
Published: May 2012

Low‐molecular‐weight hydroxyl‐terminated poly(lactic acid)s (PLA‐OHs) were synthesized via the condensation polymerization of L‐lactic acid (LA) with stannous octoate [Sn(Oct)2] as a catalyst along with a small amount of 1,4‐butanediol (1,4‐BDO). The effect of three reaction parameters (i.e., reaction time, catalyst concentration, 1,4‐BDO concentration) on the molecular weight (MW) and molecular weight distribution (MWD) of the PLA‐OHs were investigated with response surface methodology. Three levels for each parameter were selected: 6, 8, and 10 h for reaction time, 0.05, 0.10, and 0.15 mol % catalyst concentrations based on LA content, and 2, 3, and 4 mol % 1,4‐BDO concentrations based on LA content. The physicochemical structures of the polymers were investigated by Fourier transform infrared spectroscopy. The MW and MWD values of the synthesized polymers were investigated by 1H‐NMR and gel permeation chromatography. The results show that when the reaction time was increased, the MW of the PLA‐OHs increased reasonably. The MW of polymers also increased with decreasing amount of catalyst. Increasing the amount of 1,4‐BDO resulted in a decrease in the MW of the prepolymers. The only exception was observed when the lowest reaction time (6 h) was chosen along with a high concentration of 1,4‐BDO; in this case, increasing the catalyst amount resulted in an increase in MW. Also, when we chose a reaction time of 10 h, a catalyst concentration of 0.10 mol % based on LA content, and a 1,4‐BDO amount of 2 mol % based on LA content, we observed the highest MW among the other samples. Finally, an equation was developed by MINITAB software to predict the MWs of the PLA‐OHs on the basis of the reaction parameters. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Physico‐mechanical and decay resistance properties of chemically modified tropical wood material
Authors: Islam Md. Saiful , Hamdan Sinin , Hasan Mahbub , Rusop Mohamad , Rahman Md. Rezaur , Idrus M. A. M. Mohd
Published: May 2012

In this present research, several kinds of selected tropical light hardwoods were chemically modified with benzene diazonium salt to improve their physico‐mechanical and decay resistance properties. Benzene diazonium salt underwent a coupling reaction with wood which was confirmed through fourier transform infrared spectroscopic analysis. The compressive modulus of the treated wood increased, whereas modulus of rupture was shown to decrease on treatment. Water absorption was also found to decrease considerably after modification. The modified wood samples had higher hardness (Shore D) value compared to that of the control ones. The wood was exposed to two types of fungi; white‐rot (Polyporus versicolor) and brown‐rot (Postia placenta), for 12 weeks and then decay was assessed through weight loss percentage (%). A significant improvement was found in the modified wood compared to the control wood. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
MesoDyn simulation study on the phase morphologies of miktoarm PS‐b‐PMMA copolymer doped by nanoparticles
Authors: Mu Dan , Li Jian‐Quan , Wang Song
Published: May 2012

The compatibility of six groups 12 miktoarm polystyrene‐block‐poly(methyl methacrylate) copolymers is studied at 383, 413, and 443 K via mesoscopic modeling. The values of the order parameters depend on both the architectures of the block copolymers and the simulation temperature, whereas the change tendency of the order parameters is nearly the same at 413 and 443 K. Obviously, temperature presents more obvious effect on long and PMMA‐rich chains. A study of plain copolymers doped with nanoparticles shows that the microscopic phase is influenced by not only the properties of the nanoparticles, such as the size, number, and density, but also by the composition and architecture of copolymers. Increasing the size and the number of the nanoparticles used as a dopant plays the most significant role on the phase morphologies of the copolymers at lower and higher temperatures, respectively. Especially, the 13214‐type copolymers, which are PMMA‐rich composition, present microscopic phase separation as varying degrees of lamellar phase morphologies at 443 K, alternated with PS and PMMA component. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Effect of carbon nanotube surface treatment on the morphology, electrical, and mechanical properties of the microfiber‐reinforced polyethylene/poly(ethylene terephthalate)/carbon nanotube composites
Authors: Yesil Sertan , Bayram Goknur
Published: May 2012

The aim of this study is to investigate the effects of carbon nanotube (CNT) chemical properties, CNT content, and molding temperature on the morphology, electrical, and mechanical properties of the microfiber‐reinforced polymer composites. These composites were prepared by extrusion and hot stretching the poly(ethylene terephthalate) (PET)/CNT phase in high density polyethylene (HDPE) matrix. Surfaces of the CNT were modified by purification with strong acid mixture (HNO3 : H2SO4 mixture 1 : 1 by volume) followed by treatment with poly(ethylene glycol) (PEG). In situ microfibrillar composites were prepared with untreated and modified CNT. Scanning Electron Microscopy (SEM) analyses indicated that CNT were preferentially located in PET phase of the composites. SEM micrographs of the hot‐stretched composites pointed out the existence of PET/CNT microfiber structure in HDPE phase up to 1 wt % CNT loadings and the electrical resistivities of these composites were lower than 107 ohm/cm. Tensile strength values of the composites containing 0.75 wt % CNT increased from 44 to 52 MPa after PEG treatment due to the improved mechanical strength of PET/CNT phase. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
New foamed plastic based on polyetherols obtained from 6‐aminouracil, ethylene carbonate, and propylene oxide
Authors: Chmiel‐Szukiewicz Elzbieta
Published: May 2012

Polyetherols with 1,3‐pyrimidine ring including both oxyethylene and oxypropylene groups were obtained in reactions of 6‐aminouracil with ethylene carbonate and propylene oxide. The structure of the products was analyzed by spectral methods. Some physical properties of polyetherols were investigated. The polyetherols were used as polyol components to obtain polyurethane foams. Some properties of the foams such as apparent density, absorption of water, linear dimensions stability, thermal resistance, and compression strength were investigated. The foams obtained show an improved thermal stability. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
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

Two 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

Stereocomplex‐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

In 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

Two 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

A 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

Y‐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

The 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

In 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

This 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

In 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

The 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

Low‐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

Objectives

This 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.

Methods

A 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).

Results

Marked 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.

Conclusion

This 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

BACKGROUND:

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

BACKGROUND:

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

BACKGROUND:

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.