bluuebunny/crossref_metadata_2025_split huggingface dataset:
A least squares temporal difference actor–critic algorithm with applications to warehouse management
Authors: Estanjini Reza Moazzez , Li Keyong , Paschalidis Ioannis Ch. 
Published: March 2012

AbstractThis article develops a new approximate dynamic programming (DP) algorithm for Markov decision problems and applies it to a vehicle dispatching problem arising in warehouse management. The algorithm is of the actor‐critic type and uses a least squares temporal difference learning method. It operates on a sample‐path of the system and optimizes the policy within a prespecified class parameterized by a parsimonious set of parameters. The method is applicable to a partially observable Markov decision process setting where the measurements of state variables are potentially corrupted, and the cost is only observed through the imperfect state observations. We show that under reasonable assumptions, the algorithm converges to a locally optimal parameter set. We also show that the imperfect cost observations do not affect the policy and the algorithm minimizes the true expected cost. In the warehouse application, the problem is to dispatch sensor‐equipped forklifts in order to minimize operating costs involving product movement delays and forklift maintenance. We consider instances where standard DP is computationally intractable. Simulation results confirm the theoretical claims of the article and show that our algorithm converges more smoothly than earlier actor–critic algorithms while substantially outperforming heuristics used in practice. © 2012 Wiley Periodicals, Inc. Naval Research Logistics, 2012
A wideband fast multipole accelerated boundary integral equation method for time‐harmonic elastodynamics in two dimensions
Authors: Takahashi Toru 
Published: March 2012

SUMMARYThis article presents a wideband fast multipole method (FMM) to accelerate the boundary integral equation method for two‐dimensional elastodynamics in frequency domain. The present wideband FMM is established by coupling the low‐frequency FMM and the high‐frequency FMM that are formulated on the ingenious decomposition of the elastodynamic fundamental solution developed by Nishimura's group. For each of the two FMMs, we estimated the approximation parameters, that is, the expansion order for the low‐frequency FMM and the quadrature order for the high‐frequency FMM according to the requested accuracy, considering the coexistence of the derivatives of the Helmholtz kernels for the longitudinal and transcendental waves in the Burton–Muller type boundary integral equation of interest. In the numerical tests, the error resulting from the fast multipole approximation was monotonically decreased as the requested accuracy level was raised. Also, the computational complexity of the present fast boundary integral equation method agreed with the theory, that is, Nlog N, where N is the number of boundary elements in a series of scattering problems. The present fast boundary integral equation method is promising for simulations of the elastic systems with subwavelength structures. As an example, the wave propagation along a waveguide fabricated in a finite‐size phononic crystal was demonstrated. Copyright © 2012 John Wiley & Sons, Ltd.
High‐k nanocomposites with modified double layer in carbon black‐epoxy system
Authors: Yang Yooseong , Jee Sang Soo , Lee Eun Sung , Lee Sangmock , Kim Seyun , Lee Jae‐Chan , Son Bui Thanh , Bae Jin‐Young 
Published: March 2012

AbstractHigh dielectric constant (K), low dielectric loss (tan δ) polymer nanocomposite is achieved by introducing a modified electrical double layer in the carbon black (CB)‐epoxy system, rather than by exploiting the percolation of CB in the epoxy system, in which both the dielectric constant and loss are increased simultaneously. The modified electrical double layer is introduced in CB‐epoxy system when nanosized nickel oxides embedded in CB absorbs anionic surfactants. In addition to the ionic charges on the CB, high‐k and low dielectric loss can be obtained because of CB passivation with the polymeric surfactant. The CB‐epoxy nanocomposite containing 3.1 vol% of modified CB exhibited a high dielectric constant of K 5200 and a low dielectric loss of tan δ 45% at 1 MHz. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers
Polypropylene/natural rubber composites filled with recycled newspaper: Effect of chemical treatment using maleic anhydride‐grafted polypropylene and 3‐aminopropyltriethoxysilane
Authors: Osman H. , Ismail H. , Mariatti M. 
Published: March 2012

AbstractA study on effect of chemical treatment using maleic anhydride‐grafted polypropylene (MAPP) and 3‐aminopropyltiethoxysilane (3‐APE) was investigated. The performance of the MAPP and 3‐APE were investigated by means of torque development, mechanical properties, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), scanning electron microscopy morphology, and water absorption. The results revealed that the use of MAPP or 3‐APE in the composites has increased the stabilization torque, tensile strength, Young's modulus, water absorption, and thermal stability of the PP/NR composites. The incorporation of MAPP in the composites shows higher stabilization torque, tensile strength, EB, Young's modulus, and lower water uptake when compared with the use of 3‐APE in the PP/NR composites. TGA and DSC results indicated that primary and secondary peak of DTG curve, initial degradation temperature (T0), degradation temperature (Tdeg), melting temperature (Tm), heat of fusion of composites (ΔHf(com)), crystallinity of composites (XPP), and PP (XPP) increased, while total weight loss and thermal degradation rate decreased for both treated composites. The MAPP‐treated RNP‐filled PP/NR composites were found to be more thermal resistance and more crystalline than 3‐APE‐treated filled PP/NR RNP composites. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers
Polycarbonate/molybdenum disulfide/carbon black composites: Physicomechanical, thermal, wear, and morphological properties
Authors: Basavaraj E. , Ramaraj B. , Siddaramaiah  
Published: March 2012

AbstractTo investigate the influence of molybdenum disulfide (MoS2) as solid lubricant and filler on the polycarbonate (PC) and carbon black (CB) composites, PC containing one weight percentage of CB powder was compounded and extruded with 0.5, 1.0, 2.0, and 3.0 weight percentage of MoS2 powder in a co‐rotating twin screw extruder. Thus, the fabricated PC/CB/MoS2 composites were characterized for physicomechanical properties such as density, void content, surface hardness, tensile behaviors, and impact strength. The thermal characteristics of the composites have been studied by differential scanning calorimetry and dynamic mechanical analysis (DMA). The effect of MoS2 content, loads and sliding distances on wear characteristics of the composites were evaluated using pin‐on‐disc equipment. It was found that wear, friction, and laser etching resistance of PC/CB/MoS2 composites increased with increase in MoS2 content along with improvement in tensile and impact strengths. DMA analysis indicates the storage modulus of PC/CB/MoS2 composites increased with increase in MoS2 content below the glass transition temperature (Tg) of PC. Worn surfaces and laser etched surfaces were examined with scanning electron microscopy and optical microcopy respectively to have better insight of the wear and laser etching mechanism. It was observed that the MoS2 as solid lubricant played major role in improving resistance to wear, friction, and laser etching. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers
Multifunctional high‐density polyethylene nanocomposites produced by incorporation of exfoliated graphene nanoplatelets 2: Crystallization, thermal and electrical properties
Authors: Jiang Xian , Drzal Lawrence T. 
Published: March 2012

AbstractThis research investigates the effect of exfoliated graphene nanoplatelets (GNP) on the crystallization behavior, thermal conductivity, and electrical conductivity of high‐density polyethylene (HDPE)/GNP nanocomposites. HDPE/GNP nanocomposites were fabricated by melt blending followed with injection molding. Results indicate that GNP is a good nucleating agent at low loading levels and as a result can significantly increase crystallization temperature and crystallinity of HDPE. At high GNP loadings, however, the close proximity of GNP particles retards the crystallization process. The thermal stability and thermal conductivity of HDPE/GNP nanocomposites were found to be significantly enhanced as a function of GNP concentration owing to the excellent thermal properties of GNP. Finally, the high percolation threshold of HDPE/GNP nanocomposites (∼10–15 vol%), prepared by melt blending and injection molding was successfully reduced to around 5 vol% of GNP loading by employing a novel compounding method, solid‐state ball milling. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers
Role of radicals in UV‐initiated postplasma grafting of poly‐ε‐caprolactone: An electron paramagnetic resonance study
Authors: De Cooman Hendrik , Desmet Tim , Callens Freddy , Dubruel Peter 
Published: March 2012

AbstractElectron paramagnetic resonance (EPR) measurements were performed on poly‐ε‐caprolactone (PCL) films at different stages of the postplasma‐grafting process. PCL films prepared by solvent casting (SC) or electrospinning (ESP) yield very similar EPR spectra after Ar‐plasma treatment and subsequent exposure to air, but the EPR signal is much stronger in the PCL‐ESP films. The free radicals appear to be mainly, and possibly exclusively, oxygen centered. The radicals generated by UV irradiation in PCL‐ESP films were studied in situ with EPR, using a UV‐LED (λ = (285 ± 5) nm). Their EPR spectrum is distinctly different from the plasma‐induced signal, indicative of carbon‐centered radicals, and appears to be independent of the plasma pretreatment. UV‐induced homolytic splitting of (hydro)peroxide bonds was not observed. Both the plasma‐ and UV‐induced radicals decay at room temperature (RT), even in an inert atmosphere. This study demonstrates the potential of electrospun films and UV‐LEDs for the study of plasma‐ and UV‐generated free radicals with EPR in polyesters, and raises questions with respect to the validity of some generally accepted molecular mechanisms underpinning the postplasma grafting technique for polyesters. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
A multifunctional poly(aryl ether) with oligoaniline and fluorene pendants: Synthesis, electrochromic performance, and tunable fluorescent properties
Authors: Chao Danming , Yang Rui , Jia Xiaoteng , Liu Hongtao , Wang Shutao , Wang Ce , Berda Erik B. 
Published: March 2012

AbstractA novel multifunctional poly(aryl ether) with both pendant oligoaniline and fluorene groups (PAE‐p‐OF) was synthesized by nucleophilic polycondensation and characterized by 1H NMR, Fourier‐transform infrared spectra, and gel permeation chromatography. The polymer showed excellent solubility in common organic solvents and good thermal stability. Electrochemical and photophysical properties were also investigated using cyclic voltammetry, UV–vis, and fluorescence spectroscopies. The obtained PAE‐p‐OF exhibits satisfactory electrochromic properties with high contrast value, acceptable coloration efficiency, and moderate switching times. Moreover, the fluorescence intensity of PAE‐p‐OF was modulated by controlling oxidation degree of oligoaniline moiety, due to the energy migration occurring between oligoaniline and fluorene groups. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
Thermal frontal polymerization with a thermally released redox catalyst
Authors: Parrinello Claudio Attardo , Bounds Christopher O. , Liveri Maria Liria Turco , Pojman John A. 
Published: March 2012

AbstractWe studied thermal frontal polymerization using a redox system in an attempt to lower the temperature of the frontally polymerizable system while increasing the front velocity so as to obtain a self‐sustaining front in a thinner layer than without the redox components. A cobalt‐containing polymer with a melting point of 63 °C (Intelimer 6050X11) and cumene hydroperoxide were used with a triacrylate. The use of the Intelimer decreased the front velocity but allowed fronts to propagate in thinner layers and with more filler while still having a pot life of days. Nonplanar modes of propagation occurred. Fronts propagated faster when 6‐O‐palmitoyl‐L‐ascorbic acid was used as a reductant. Interestingly, fronts were also faster with the reductant even without the Intelimer if kaolin clay was the filler; however, the pot life was significantly reduced. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
Modern and Late Holocene Retrogressive Thaw Slump Activity on the Yukon Coastal Plain and Herschel Island, Yukon Territory, Canada
Authors: Lantuit H. , Pollard W. H. , Couture N. , Fritz M. , Schirrmeister L. , Meyer H. , Hubberten H.‐W. 
Published: March 2012

ABSTRACTFour retrogressive thaw slumps (RTS) located on Herschel Island and the Yukon coast (King Point) in the western Canadian Arctic were investigated to compare the environmental, sedimentological and geochemical setting and characteristics of zones in active and stabilised slumps and at undisturbed sites. In general, the slope, sedimentology and biogeochemistry of stabilised and undisturbed zones differ, independent of their age or location. Organic carbon contents were lower in slumps than in the surrounding tundra, and the density and compaction of slump sediments were much greater. Radiocarbon dating showed that RTS were likely to have been active around 300 a BP and are undergoing a similar period of increased activity now. This cycle is thought to be controlled more by local geometry, cryostratigraphy and the rate of coastal erosion than by variation in summer temperatures. Copyright © 2012 John Wiley & Sons, Ltd.
Protein–protein interaction network‐based detection of functionally similar proteins within species
Authors: Song Baoxing , Wang Fen , Guo Yang , Sang Qing , Liu Min , Li Dengyun , Fang Wei , Zhang Deli 
Published: March 2012

AbstractAlthough functionally similar proteins across species have been widely studied, functionally similar proteins within species showing low sequence similarity have not been examined in detail. Identification of these proteins is of significant importance for understanding biological functions, evolution of protein families, progression of co‐evolution, and convergent evolution and others which cannot be obtained by detection of functionally similar proteins across species. Here, we explored a method of detecting functionally similar proteins within species based on graph theory. After denoting protein–protein interaction networks using graphs, we split the graphs into subgraphs using the 1‐hop method. Proteins with functional similarities in a species were detected using a method of modified shortest path to compare these subgraphs and to find the eligible optimal results. Using seven protein–protein interaction networks and this method, some functionally similar proteins with low sequence similarity that cannot detected by sequence alignment were identified. By analyzing the results, we found that, sometimes, it is difficult to separate homologous from convergent evolution. Evaluation of the performance of our method by gene ontology term overlap showed that the precision of our method was excellent. Proteins 2012; © 2012 Wiley Periodicals, Inc.
Comparative modeling and protein‐like features of hydrophobic–polar models on a two‐dimensional lattice
Authors: Moreno‐Hernández Sergio , Levitt Michael 
Published: March 2012

AbstractLattice models of proteins have been extensively used to study protein thermodynamics, folding dynamics, and evolution. Our study considers two different hydrophobic–polar (HP) models on the 2D square lattice: the purely HP model and a model where a compactness‐favoring term is added. We exhaustively enumerate all the possible structures in our models and perform the study of their corresponding folds, HP arrangements in space and shapes. The two models considered differ greatly in their numbers of structures, folds, arrangements, and shapes. Despite their differences, both lattice models have distinctive protein‐like features: (1) Shapes are compact in both models, especially when a compactness‐favoring energy term is added. (2) The residue composition is independent of the chain length and is very close to 50% hydrophobic in both models, as we observe in real proteins. (3) Comparative modeling works well in both models, particularly in the more compact one. The fact that our models show protein‐like features suggests that lattice models incorporate the fundamental physical principles of proteins. Our study supports the use of lattice models to study questions about proteins that require exactness and extensive calculations, such as protein design and evolution, which are often too complex and computationally demanding to be addressed with more detailed models. Proteins 2012; © 2012 Wiley Periodicals, Inc.
Modeling small releases from tanks
Authors: (Rick) Knack Fredrick H. , Brown Michelle L. , (Rick) Knack Fredrick W. 
Published: March 2012

AbstractThe methodologies in the chapter on “Dispersion Modeling” in the CCPS book Guidelines for Consequence Analysis of Chemical Releases provide means for modeling outdoor releases at relatively long distances from a large source. At times it is necessary to model releases at relatively short distances from a small source. Making the assumption that the model as developed is valid at the near range, it was used to estimate the levels of ethanol that are emitted from indoor mixing tanks and the potential operator exposure to carbon dioxide released from a lithium bromide manufacturing operation. This article presents the development, implementation, and results of using the model for small releases from tanks. © 2012 American Institute of Chemical Engineers Process Saf Prog, 2012
Structural properties of solid solutions of the non‐dimerized, 3/4‐filled conductors (o‐DMTTF)2X (X = Cl, Br, I)
Authors: Reinheimer Eric W. , Assaf Ali , Jeannin Olivier , Benallouche Abla , Nguyen Phuong‐Tien , Coulon Claude , Fourmigué Marc 
Published: March 2012

AbstractHalide salts of the unsymmetrically substituted o‐DMTTF, formulated as (o‐DMTTF)2X, X = Cl, Br, I, are organized into uniform chains in a tetragonal structure with space group I‐42d, providing a rare example of non‐dimerized 3/4 filled system. Solid solutions formulated as (o‐DMTTF)(Br)x(Cl)1−x and (o‐DMTTF)2(Br)x(I)1−x have been prepared and structurally characterized. A systematic preferential bromide insertion is observed together with a lateral expansion of the structure with increasing anion size.magnified image
Tetragonal (space group I–42d) structure of the halide salts of o‐DMTTF, in solid solutions (o‐DMTTF)2(X)x(Y)1−x.
Electronic states and nonlinear optical properties of a two‐dimensional hexagonal quantum dot: Effects of impurity, geometrical size and confinement potential
Authors: Rezaei G. , Azami S. M. , Vaseghi B. 
Published: March 2012

AbstractIn the present work, the linear and the third‐order nonlinear optical absorption coefficients as well as refractive‐index changes in a two‐dimensional hexagonal quantum dot with the presence of an impurity are calculated. A matrix diagonalization method is used to calculate energy levels and corresponding wave functions in the effective‐mass approximation. Also, by means of the compact‐density matrix approach the linear and nonlinear optical absorption coefficients and refractive‐index changes are calculated. The effects of the impurity, the size of the dot and the confinement potential on energy eigenvalues, optical absorption coefficients and refractive‐index changes are investigated. It is found that the energy eigenvalues, absorption coefficients and refractive‐index changes are strongly dependent on the dot size, the confinement potential and the effects produced by the impurity.
Magnetic structure and bonding of rare‐earth diboride compounds RB2: First‐principles calculations
Authors: Kacimi S. , Bekkouche B. , Boukortt A. , Zazoua F. , Djermouni M. , Zaoui A. 
Published: March 2012

AbstractThe electronic structure and magnetic behavior of hexagonal rare‐earth diboride RB2 are studied using ab initio density‐functional theory in the DFT + U approach. The effect of the spin–orbit coupling is also investigated and it is found to be a necessary requirement for the accurate description of the magnetic moment. In this paper, we study the magnetic phase stability of RB2 compounds; the band structure and the density of state (DOS) results prove that the coulomb potential and the spin–orbit interaction are keys factors to understand the magnetic properties of these series of materials. In addition, we also explain the behavior of a chemical bond of RB2 compounds through the analysis of the DOS and of the charge density.
Nondestructive investigation of interface states in high‐k oxide films on Ge substrate using X‐ray absorption spectroscopy
Authors: Cho Deok‐Yong , Jung Hyung‐Suk , Yu Il‐Hyuk , Park Won Goo , Cho Suyeon , Kim Useong , Oh Se‐Jung , Park Byeong‐Gyu , Chang Fan‐Hsiu , Lin Hong‐Ji , Hwang Cheol Seong 
Published: March 2012

AbstractThe unoccupied electronic structures of 5 nm thick high permittivity (k) oxides (HfO2, ZrO2, and Al2O3) and SiO2 films on Ge substrates were examined using O K‐edge X‐ray absorption spectroscopy. Comparative studies with those on Si substrates showed contrasts in the conduction bands, which should be due to the formation of interface states. In the Al2O3 and SiO2 films, GeO2 layers are formed at the interface and they suppress in part the formation of detrimental germanate phases. In contrast, in the HfO2 and ZrO2 films, no signature of the Ge‐oxide phase is observed but some germanate phases are expected to prevail, suggesting a degradation of the gate oxide characteristics. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Testing the broad applicability of the PBEint GGA functional and its one‐parameter hybrid form
Authors: Fabiano E. , Constantin Lucian A. , Della Sala F. 
Published: March 2012

AbstractWe review the performance of the PBEint generalized gradient approximation functional (Fabiano et al., Phys. Rev. B 2010, 82, 113104) recently proposed to improve the description of hybrid interfaces, and we introduce its one‐parameter hybrid form (hPBEint). We consider different well‐established benchmarks for energetic and structural properties of molecular and solid‐state systems as well as model systems and newly developed benchmark sets for dipole moments and metal–molecule interactions. We find that PBEint and hPBEint (with 16.67% Hartree–Fock exchange) yield the overall best performance, working well for most of the considered properties and systems and showing a balanced behavior for different problems. In particular, due to their well‐balanced accuracy, they perform well for the description of hybrid metal–molecule interfaces. © 2012 Wiley Periodicals, Inc.