bluuebunny/crossref_metadata_2025_split huggingface dataset:
A note on “resource flexibility with responsive pricing”
Authors: Bish Ebru K. , Liu Juqi , Bish Douglas R. 
Published: January 2010

AbstractWe revisit the capacity investment decision problem studied in the article “Resource Flexibility with Responsive Pricing” by Chod and Rudi [Operations Research 53, (2005) 532–548]. A monopolist firm producing two dependent (substitutable or complementary) products needs to determine the capacity of one flexible resource under demand risk so as to maximize its expected profit. Product demands are linear functions of the prices of both products, and the market potentials are random and correlated. We perform a comparative statics analysis on how demand variability and correlation impact the optimal capacity and the resulting expected profit. In particular, C&R study this problem under the following assumptions/approximations: (i) demand intercepts follow a bivariate Normal distribution; (ii) demand uncertainty is of an additive form; (iii) and under approximate expressions for the optimal capacity and optimal expected profit. We revisit Propositions 2, 3, 4, 5, and 10 of C&R without these assumptions and approximations, and show that these results continue to hold (i) for the exact expressions for the optimal expected profit and optimal capacity, and (ii) under any arbitrary continuous distribution of demand intercepts. However, we also show that the additive demand uncertainty is a critical assumption for the C&R results to hold. In particular, we provide a case of multiplicative uncertainty under which the C&R results (Propositions 2 and 3) fail. © 2010 Wiley Periodicals, Inc. Naval Research Logistics 2010
Scheduling with variable time slot costs
Authors: Wan Guohua , Qi Xiangtong 
Published: January 2010

AbstractIn this article, we study a class of new scheduling models where time slot costs have to be taken into consideration. In such models, processing a job will incur certain cost which is determined by the time slots occupied by the job in a schedule. The models apply when operational costs vary over time. The objective of the scheduling models is to minimize the total time slot costs plus a traditional scheduling performance measure. We consider the following performance measures: total completion time, maximum lateness/tardiness, total weighted number of tardy jobs, and total tardiness. We prove the intractability of the models under general parameters and provide polynomial‐time algorithms for special cases with non‐increasing time slot costs.© 2010 Wiley Periodicals, Inc. Naval Research Logistics, 2010
Optimal control of a production‐inventory system with both backorders and lost sales
Authors: Benjaafar Saif , ElHafsi Mohsen , Huang Tingliang 
Published: January 2010

AbstractWe consider the optimal control of a production inventory‐system with a single product and two customer classes where items are produced one unit at a time. Upon arrival, customer orders can be fulfilled from existing inventory, if there is any, backordered, or rejected. The two classes are differentiated by their backorder and lost sales costs. At each decision epoch, we must determine whether or not to produce an item and if so, whether to use this item to increase inventory or to reduce backlog. At each decision epoch, we must also determine whether or not to satisfy demand from a particular class (should one arise), backorder it, or reject it. In doing so, we must balance inventory holding costs against the costs of backordering and lost sales. We formulate the problem as a Markov decision process and use it to characterize the structure of the optimal policy. We show that the optimal policy can be described by three state‐dependent thresholds: a production base‐stock level and two order‐admission levels, one for each class. The production base‐stock level determines when production takes place and how to allocate items that are produced. This base‐stock level also determines when orders from the class with the lower shortage costs (Class 2) are backordered and not fulfilled from inventory. The order‐admission levels determine when orders should be rejected. We show that the threshold levels are monotonic (either nonincreasing or nondecreasing) in the backorder level of Class 2. We also characterize analytically the sensitivity of these thresholds to the various cost parameters. Using numerical results, we compare the performance of the optimal policy against several heuristics and show that those that do not allow for the possibility of both backordering and rejecting orders can perform poorly.© 2010 Wiley Periodicals, Inc. Naval Research Logistics 2010
PA66/PA12/clay based nanocomposites: morphology and physical properties
Authors: Besco Stefano , Lorenzetti Alessandra , Roso Martina , Modesti Michele 
Published: January 2010

AbstractThe structure and the physical properties of several polyamide 66 (PA66)/polyamide 12 (PA12) blends containing different amounts of the two polymers and obtained by melt‐blending have been investigated. A low amount of organically‐modified layered silicate (OMLS, 4 wt%) has also been introduced in order to further improve the physical properties and, in particular, to evaluate its effect on the blends' structure and components' miscibility. The microstructure and morphology of all the composites were analyzed by means of X‐Ray diffraction (WAXD), transmission electron microscopy (TEM), and high resolution scanning electron microscopy (SEM), while the macroscopic scale properties (mechanical behavior and water adsorption) were assessed in order to investigate and understand the materials' structure–properties relationships. The partial miscibility of PA66 and PA12, with phase separation depending on blend composition, has been confirmed. The results also underlined the possibility to tailor the behavior of polymer blends in terms of mechanical water adsorption properties by varying the amount of PA12, added to PA66 with and without the addition of the OLMS. The effectiveness of the clay in modifying the components' miscibility as well as its tendency to segregate preferentially within separate PA66 domains have been assessed. WAXD results showed opposite effects of PA12 and clay on the crystallization behavior of PA66, an aspect that has also been deepened in another paper by the same authors discussing the results of the complete thermal characterization. Copyright © 2010 John Wiley & Sons, Ltd.
Electrochemical impedance characterization and photovoltaic performance of N719 dye‐sensitized solar cells using quaternized ammonium iodide containing polyfluorene electrolyte solutions
Authors: Lee Rong‐Ho , Huang Yu‐Wei , Chang Jhih‐Wei , Hwang Jenn‐Chiu , Chen Yung‐Chung , Jeng Ru‐Jong 
Published: January 2010

AbstractThis study develops a series of titanium oxide electrode‐based N719 dye‐sensitized solar cells (DSSCs) using quaternized ammonium iodide containing main‐chain and star‐shaped polyfluorene (MPF‐E and SPF‐E) electrolyte solutions. The electrochemical impedance and photovoltaic properties of the polyfluorene electrolyte‐based DSSCs were studied and compared to those of the poly(ethylene oxide) (PEO) electrolyte‐based DSSCs. As with the PEO electrolyte‐based DSSCs, the recombination impedance increased with increase in the polymer content for the MPF‐E electrolyte‐based DSSCs, whereas the photovoltaic performance did otherwise. Nevertheless, the reduction in the photovoltaic properties was not significant for the SPF‐E electrolyte‐based DSSCs. The electrochemical impedance and photovoltaic properties of the different polymer‐based DSSCs are also discussed as a function of the polymer concentration. Copyright © 2010 John Wiley & Sons, Ltd.
Newly emerging applications of halloysite nanotubes: a review
Authors: Du Mingliang , Guo Baochun , Jia Demin 
Published: January 2010

AbstractHalloysite nanotubes (HNTs) are types of naturally occurring 1:1 clays with nanotubular structures and similar chemical composition to kaolin. Due to various characteristics such as nanoscale lumens, high length‐to‐diameter ratio, relatively low hydroxyl group density on the surface, etc., numerous exciting applications have been discovered for this unique, cheap and abundantly deposited clay. After briefly summarizing applications in controlled release, nanotemplating and sorption, we emphasize the applications of HNTs in the fabrication of polymer nanocomposites. The unique structures and performance of HNT‐incorporated polymer nanocomposites processed by various routes are described. The results suggest that these nanocomposites exhibit remarkable performance such as reinforcing effects, enhanced flame retardancy and reduced thermal expansion. Accordingly, HNTs should be of interest in the area of polymer nanocomposites for structural and functional applications. Copyright © 2010 Society of Chemical Industry
Ionic polymer–metal composite mechanoelectrical transduction: review and perspectives
Authors: Pugal Deivid , Jung Kwangmok , Aabloo Alvo , Kim Kwang J 
Published: January 2010

AbstractThis paper presents a comprehensive review of the use of ionic polymer‐metal composite (IPMC) materials as mechanoelectrical transducers. Recently increasing emphasis has been put on the research of IPMCs as displacement or velocity sensors for various applications. This has resulted in various theories and models to describe the mechanoelectrical transduction phenomenon. The paper gives an overview of the proposed transduction principles, developed models and the latest applications. In more detail, the history of IPMC materials, the physics and the electrochemistry behind the mechanoelectrical transduction, different black‐box and gray‐box models, and novel real‐world mechatronics‐related applications are discussed throughout the paper. However, despite the latest advancements in the research of IPMC transduction, there is still a certain amount of controversy regarding some of the IPMC sensorial properties. For instance, it has been noticed by several authors that there is a signal delay when bending an IPMC. The general understanding of the physical principles about regular IPMC mechanoelectrical transduction is rather good. In the last section of the paper novel results are presented for copper‐coated IPMC materials. Apparently the electrochemistry behind the transduction for copper‐coated IPMCs is significantly different. Besides ionic diffusion, chemical reactions on the electrodes also occur and dominate the actuation process. Experimental results show some promising opportunities for designing new copper‐coated IPMC‐based sensors. Copyright © 2010 Society of Chemical Industry
An investigation of the effect of silane water‐crosslinking on the properties of poly(L‐lactide)
Authors: Han Changyu , Bian Junjia , Liu Hao , Han Lijing , Wang Shusheng , Dong Lisong , Chen Shan 
Published: January 2010

AbstractA silane‐grafting water‐crosslinking approach was developed to crosslink poly(L‐lactide) (PLLA) by grafting vinylalkoxysilane onto PLLA using dicumyl peroxide, followed by silane hydrolysis to form siloxane linkages between PLLA chains. The degree of silane grafting onto PLLA was qualitatively characterized using Fourier transform infrared spectroscopy and quantitatively determined using inductively coupled plasma mass spectrometry. Crosslinked PLLA films were obtained by curing of silane‐grafted PLLA in hot water. Gel fractions were evaluated in order to calculate the crosslinking reaction kinetics and crosslinking density. Various techniques were used to investigate the effect of silane water‐crosslinking on the thermomechanical properties, hydrolysis resistance and biodegradation of PLLA. In addition to an improvement in thermal stability and mechanical properties, hydrolysis resistance was significantly enhanced as a result of silane water‐crosslinking of PLLA. Moreover, the biodegradation of silane water‐crosslinked PLLA was retarded compared with neat PLLA. Copyright © 2010 Society of Chemical Industry
Micellar behavior of well‐defined polystyrene‐based block copolymers with triethoxysilyl reactive groups and their hydrolysis–condensation
Authors: Gamys Cé Guinto , Beyou Emmanuel , Bourgeat‐Lami Elodie 
Published: January 2010

AbstractBlock copolymers of acryloxy propyl triethoxysilane and styrene were prepared through nitroxide‐mediated polymerization using alkoxyamine initiators based on N‐tert‐butyl‐1‐diethylphosphono‐2,2‐dimethylpropyl nitroxide. The copolymers were characterized by 1H NMR, size exclusion chromatography and differential scanning calorimetry. Their micellar behavior in dioxane/methanol solutions was examined through static light scattering and transmission electron microscopy (TEM). TEM indicated the successful formation of spherical micelles which were subsequently frozen by the sol–gel process. Hydrolysis–condensation of the reactive ethoxysilyl side groups was followed by FTIR, 1H NMR, and 29Si NMR. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 784–793, 2010
Effects of tetracarboxylic dianhydrides on the properties of sulfonated polyimides
Authors: Chen Xinbing , Chen Kangcheng , Chen Pei , Higa Mitsuru , Okamoto Ken‐Ichi , Hirano Tetsuji 
Published: January 2010

AbstractA series of sulfonated polyimides (SPIs) were synthesized from a sulfonated diamine of 4,4′‐bis(4‐aminophenoxy) biphenyl‐3,3′‐disulfonic acid (BAPBDS), common nonsulfonated diamines, and various tetracarboxylic dianhydrides including 1,4,5,8‐naphthalene tetracarboxylic dianhydride (NTDA), 3,4,9,10‐perylene tetracarboxylic dianhydride (PTDA), 4,4′‐binaphthyl‐1,1′,8,8′‐tetracarboxylic dianhydride (BTDA), 4,4′‐ketone dinaphthalene 1,1′,8,8′‐tetracarboxylic dianhydride (KDNTDA), and isophthatic dinaphthalene 1,1′,8,8′‐tetracarboxylic dianhydride (IPNTDA). Their membrane properties were investigated to clarify the effects of the dianhydrides. They displayed reasonably high mechanical properties, thermal stability, and proton conductivity. The dianhydrides with flexible and non‐coplanar structure (IPNTDA > KDNTDA > BTDA) led to the better solubility of the SPIs than those with rigid and coplanar one (NTDA, PTDA). The dianhydride with the smaller molecular weight led to the larger value of the number of sorbed water molecules per sulfonic acid group (λ) in membrane, that is, NTDA (λ: 17) > PTDA (15) > BTDA (14) > KDNTDA (12) > IPNTDA (10), and as a result let to the larger proton conductivity in water. All of the BAPBDS‐based SPIs showed the anisotropy in membrane swelling and in proton conductivity, of which the degree hardly depended on the dianhydride moieties. The water stability of SPI membranes against the aging in water at 130 °C for 192 h was in the order, PTDA = NTDA ≧ BTDA > KDNTDA > IPNTDA. The hydrolysis stability of polymer chain was similar between the BTDA‐ and KDNTDA‐based SPIs. These results are discussed. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 905–915, 2010
The preparation of amphiphilic core‐shell nanospheres by using water‐soluble macrophotoinitiator
Authors: Li Shurun , Deng Jianping , Yang Wantai 
Published: January 2010

AbstractThe amphiphilic poly(AM‐co‐SA)‐ITXH macrophotoinitiator was synthesized by precipitation photopolymerization under UV irradiation with isopropylthioxanthone (ITX) as free radical photoinitiator. A novel method has been developed to prepare amphiphilic core‐shell polymer nanospheres via photopolymerization of methyl methacrylate (MMA) in aqueous media, with amphiphilic copolymer macrophotoinitiator poly(AM‐co‐SA)‐ITXH. During polymerization, the amphiphilic macroradicals underwent in situ self‐assembly to form polymeric micelles, which promoted the emulsion polymerization of the monomer. Thus, amphiphilic core‐shell nanospheres ranging from 70 to 140 nm in diameter were produced in the absence of surfactant. The conversion of the monomer, number average molecular weights (Mn), and particle size were found to be highly dependent on the macrophotoinitiator and monomer concentration. The macrophotoinitiator and amphiphilic particles were characterized by FTIR, UV‐vis, 1H NMR, TEM, DSC, and contact angle measurements. The results showed the particles had well‐defined amphiphilic core‐shell structure. This new method is scientifically and technologically significant because it provides a commercially viable route to a wide variety of novel amphiphilic core‐shell nanospheres. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 936–942, 2010
Living/controlled cationic cyclopolymerization of divinyl ether with a cyclic acetal moiety: Synthesis of poly(vinyl ether)s with high glass transition temperature based on incorporation of cyclized main chain and cyclic side chains
Authors: Hashimoto Tamotsu , Takagi Hiromi , Hasegawa Yuko , Matsui Haruki , Urushisaki Michio , Sakaguchi Toshikazu 
Published: January 2010

AbstractCationic cyclopolymerization of 2‐methyl‐5,5‐bis(vinyloxymethyl)‐1,3‐dioxane (1), a divinyl ether with a cyclic acetal group, was investigated with the HCl/ZnCl2 initiating system in toluene and methylene chloride at −30 °C. The reaction proceeded quantitatively to give gel‐free, soluble polymers in organic solvents. The number‐average molecular weight (Mn) of the polymers increased in direct proportion to monomer conversion, and further increased on addition of a fresh monomer feed to the almost completely polymerized reaction mixture, indicating that the polymerization proceeded in living/controlled manner. The contents of the unreacted vinyl groups in the produced soluble polymers were less than ∼3 mol %, and therefore, the degree of cyclization was determined to be ∼97%. In contrast, the pendant cyclic acetal groups remained intact in the polymers under the present cationic polymerization conditions. These facts show that cyclopolymerization of 1 almost exclusively occurred and the poly(vinyl ether)s with the cyclized repeating units and cyclic pendant acetal rings were obtained. Glass transition temperature (Tg) and thermal decomposition temperature (Td) of poly(1) (Mn = 7870, Mw/Mn = 1.57) were found to be 166 and 338 °C, respectively, indicating that poly(1) had high Tg and high thermal stability. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 952–958, 2010
Controlled ring‐opening polymerization of lactide by bis‐sulfonamide/amine associations: Cooperative hydrogen‐bonding catalysis
Authors: Alba Aurélie , Schopp Aurélia , De Sousa Delgado Anne‐Paula , Cherif‐Cheikh Roland , Martín‐Vaca Blanca , Bourissou Didier 
Published: January 2010

AbstractThe bis‐sulfonamide m‐C6H4(SO2NHPh)2 efficiently promotes the ring‐opening polymerization of lactide when combined with tertiary amines, such as N,N‐dimethylaminopyridine. Polylactides of controlled molecular weights (Mn up to 17,700 g mol−1) and very narrow molecular weight distributions (Mw/Mn < 1.11) are obtained under mild conditions and in a living fashion. The reaction takes place through a bifunctional mechanism involving activation of both the alcohol and the monomer. Modulation of the sulfonamide component supports cooperative dual hydrogen‐bonding of lactide involving the two (SO2NHAr) moieties. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 959–965, 2010
Hypervalent iodine‐mediated direct azidation of polystyrene and consecutive click‐type functionalization
Authors: Tsarevsky Nicolay V. 
Published: January 2010

AbstractPolystyrene was directly azidated in 1,2‐dichloroethane or chlorobenzene using a combination of trimethylsilyl azide and a hypervalent iodine (III) compound, (diacetoxyiodo)benzene. 2D NMR HMBC experiments indicated that the azide groups were attached to the polymer backbone and also possibly to the aromatic pendant groups. The amount of introduced azide groups was estimated by semi‐quantitative IR spectroscopy and elemental analysis. Approximately 1 in every 11 styrene units could be modified by using a ratio of hypervalent iodine compound to trimethylsilyl azide to styrene units of 1:2.1:1 at 0 °C for 4 h followed by heating to 50 °C for 2 h in chlorobenzene. The azidated polymers were further used as backbone precursors in the synthesis of polymeric brushes with hydrophilic side chains via a copper‐catalyzed click grafting‐onto reaction with poly(ethylene oxide) monomethyl ether 4‐pentynoate. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 966–974, 2010
Crystallization‐induced aging in poly(trimethylene terephthalate)/ poly(ethylene oxide terephthalate) segmented block copolymers
Authors: Yao Chenguang , Yang Guisheng 
Published: January 2010

AbstractA new type poly(ether–ester) based on poly(trimethylene terephthalate) as rigid segments and poly(ethylene oxide terephthalate) as soft segments was synthesized and its aging behavior were investigated. Different from other polymer, the segmented block copolymers exhibited a unique aging mechanism. That is, the degradation of mechanical property within short term annealing was due to the overgrown crystals and dramatically increased crystallinity, which was proved by field emission scanning electron microscope (FE‐SEM) and differential scanning calorimetry (DSC), respectively. The deterioration in mechanical property after long term annealing was the results of both the increase in crystallinity and the decrease in molecular weight. Moreover, FE‐SEM showed many interesting flower‐like crystals presented on the surface of annealed sample. The flower‐like crystals consist of several radialized petal‐like arms and a more densely packed center, which has been seldom found in polymer bulk. Wide‐angle x‐ray diffraction results showed that the copolymer has the same crystal structure as PTT. Such poly(ether–ester) or its blends with other polymer could be suitable for rapid degradable products, such as package and vessel. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 411–416, 2010
Thermal and mechanical properties of a dendritic hydroxyl‐functional hyperbranched polymer and tetrafunctional epoxy resin blends
Authors: Zhang Jin , Guo Qipeng , Fox Bronwyn 
Published: January 2010

AbstractBlends of a tetrafunctional epoxy resin, tetraglycidyl‐4,4′‐diaminodiphenylmethane (TGDDM), and a hydroxyl‐functionalized hyperbranched polymer (HBP), aliphatic hyperbranched polyester Boltorn H40, were prepared using 3,3′‐diaminodiphenyl sulfone (DDS) as curing agent. The phase behavior and morphology of the DDS‐cured epoxy/HBP blends with HBP content up to 30 phr were investigated by differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), and scanning electron microscopy (SEM). The phase behavior and morphology of the DDS‐cured epoxy/HBP blends were observed to be dependent on the blend composition. Blends with HBP content from 10 to 30 phr, show a particulate morphology where discrete HBP‐rich particles are dispersed in the continuous cured epoxy‐rich matrix. The cured blends with 15 and 20 phr exhibit a bimodal particle size distribution whereas the cured blend with 30 phr HBP demonstrates a monomodal particle size distribution. Mechanical measurements show that at a concentration range of 0–30 phr addition, the HBP is able to almost double the fracture toughness of the unmodified TGDDM epoxy resin. FTIR displays the formation of hydrogen bonding between the epoxy network and the HBP modifier. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 417–424, 2010