bluuebunny/crossref_metadata_2025_split huggingface dataset:
Surface roughness and light transmission of biaxially oriented polypropylene films
Authors: Lin Y.J. , Dias P. , Chum S. , Hiltner A. , Baer E. 
Published: September 2007

AbstractThe effect of thermal history on the transparency of biaxially‐oriented polypropylene (BOPP) films was investigated. Compression molded sheets prepared with different cooling rates were biaxially oriented at several temperatures. Correlations were sought between the light transmission measured at 633 nm and the surface roughness as characterized by atomic force microscopy. It was determined that surface roughness on the 100‐μm size scale was responsible for a loss in transparency. Surface roughness on the submicron size scale did not affect the transparency. The clearest films were obtained from compression molded sheets with the most homogeneous texture and by orienting at the lowest temperature. POLYM. ENG. SCI., 47:1658–1665, 2007. © 2007 Society of Plastics Engineers
Study on grafting maleic anhydride onto polypropylene in microcolloid systems by coirradiation
Authors: Tan Xiumin , Xu Yongshen , Qian Jun , Wang Chonglin 
Published: September 2007

AbstractGrafting of maleic anhydride (MAH) onto polypropylene (PP) performed in microcolloid systems by coirradiation was studied in this paper. First, the microcolloid of PP and MAH in xylene was prepared and its dynamic light scattering (DLS) shows particle size distributions of microcolloid system in 4–6 μm. Second, the effect of irradiation dose and monomer concentration on the amount of grafted MAH was investigated. The results show that the coirradiation in microcolloid systems can obviously cause an increase of the amount of grafted MAH. The percentage of grafting of the product amounts to 5.24%. The molecular structures of grafted MAH prepared were characterized by Fourier‐transform infrared spectroscopy. Differential scanning calorimetry and wide‐angle X‐ray diffraction were used to determine the degree of crystallinity and crystalline structure. POLYM. ENG. SCI., 47:1703–1707, 2007. © 2007 Society of Plastics Engineers
A test method for studying the rolling resistance of rubber compounds
Authors: Gent A.N. , Gallagher D.D. , Steven R.B. 
Published: September 2007

AbstractA test method is described for measuring energy losses in rolling, using the damped oscillations of a pendulum that makes a rigid cylinder roll backwards and forwards across a rubber block (Gent et al. U.S. Patent No. 6,494,076 B1, The Goodyear Tire and Rubber Company, December 17 (2002)). The mechanics of small swings, in which the displacement of the contact patch is smaller than its length, are shown to be different from those governing swings of larger amplitude. Thus, starting with relatively large swings of the pendulum, the amplitude of oscillation decays initially at a constant rate and then changes to a decreasing rate as the swings become small. In principle, the two processes provide separate measures of the energy losses in rolling. The proposed test method may be useful for studying the effects of the surface features of tire treads and road surfaces on tire rolling resistance, in addition to characterizing the dissipative properties of rubber compounds. POLYM. ENG. SCI., 47:1576–1579, 2007. © 2007 Society of Plastics Engineers
Preparation of intercalating agent‐free epoxy/clay nanocomposites
Authors: Sun Luyi , Boo Woong J. , Liu Jia , Tien Chi‐Wei , Sue Hung‐Jue , Marks Maurice J. , Pham Ha 
Published: September 2007

AbstractA simple intercalating agent‐free approach to prepare epoxy/montmorillonite (MMT) clay nanocomposite is reported. Through this new approach, no organic modifiers are needed. Thus, the cost for preparing polymer nanocomposites can be significantly reduced. The extent of dispersion and exfoliation of clay in epoxy was characterized by X‐ray diffraction and transmission electron microscopy observations. It is found that the MMT clay is well‐dispersed in epoxy matrix. The clay platelets in epoxy show a stacked structure with dimensions of about 1–2 μm in length and about 20 nm in thickness. At 4.5 wt% of clay loading level, the flexural modulus of the epoxy nanocomposite is increased by about 35%. No reduction in fracture toughness or glass‐transition temperature is observed. The implication of the present finding for commercialization of polymer nanocomposites is discussed. POLYM. ENG. SCI., 47:1708–1714, 2007. © 2007 Society of Plastics Engineers
Effects of clay on the morphology of poly(acrylonitrile‐butadiene‐styrene) and polypropylene nanocomposites
Authors: Sung Y.T. , Kim Y.S. , Lee Y.K. , Kim W.N. , Lee H.S. , Sung J.Y. , Yoon H.G. 
Published: September 2007

AbstractThe effects of clay on the morphology of the poly(acrylonitrile‐butadiene‐styrene) (ABS)/polypropylene (PP) nanocomposites were investigated. From the studies of wide angle X‐ray diffraction (WAXD) and transmission electron microscopy (TEM) analysis of the ABS/PP (70/30) nanocomposites with clay, it was observed that most of the clay existed in the ABS matrix because of the good affinity between the ABS and clay which contained benzyl group. From the studies of the scanning electron microscopy (SEM) analysis, the size of the PP droplet decreased with clay from 16.7 to 5.6 μm when the clay was added up to 4.0 phr. When the clay content was increased, the droplet of the dispersed phase (PP) was shown to elongated structure. The elongated structure could be explained by the decrease of the viscosity ratio of the PP and continuous phase (ABS) with clay, which corresponded to the increase of the viscosity of the continuous phase (ABS/clay). From the results of the SEM, TEM, and WAXD analysis, it is suggested that the increase of the viscosity of the continuous phase (ABS/clay) is mainly due to the location of clay in the ABS matrix. POLYM. ENG. SCI., 47:1671–1677, 2007. © 2007 Society of Plastics Engineers
Discontinuous deformation in an elastic material. Part 1. Energy dissipative and storage applications
Authors: Raman Arun , Farris Richard J. 
Published: September 2007

AbstractThe concept of energy or work dissipation from a perfectly elastic material, due to a discontinuous deformation mechanism, is developed in this study. Dissipation occurs even from a perfectly elastic material, preferably an elastomer, when subjected to a discontinuous “jump” stretch or “jump” contraction. Stretching an elastomeric member through free extension requires a large amount of work. Such a sudden jump stretch of an elastic material is difficult to accomplish and is equivalent to thermodynamic free compression of a gas. The amount of work required can greatly exceed the strain energy stored in the material if the extension were applied without the jump or “shock” process. Interestingly, only part of the stored energy is recovered on unloading the elastomer the same way (through contraction). Excess work lost in contraction dissipates as heat but is not due to the common viscoelastic/plastic losses associated with internal friction in solids. Dissipation is possible even from a perfectly elastic material. Energy values associated in this jump deformation process are independent of the stress–strain curve path, and depend only on initial and final states for the material. Heat dissipation from an elastic rubber belt is examined and some applications extended from the developed principle are enunciated. POLYM. ENG. SCI., 47:1511–1520, 2007. © 2007 Society of Plastics Engineers
Novel fire resistant matrixes for composites from cyclic poly(butylene terephthalate) oligomers
Authors: Tripathy Amiya R. , Farris Richard J. , MacKnight William J. 
Published: September 2007

AbstractThe objective of the work is to exploit the processing advantages of c‐PBT oligomers, essentially required in industrial practice to produce new, robust, multifunctional hybrid copolymers of c‐PBT oligomers in a single reaction‐molding step, which will be suitable for the use in continuous fiber composites with excellent flame retardant properties. In this article a series of copolyesters were synthesized by using in situ polymerization of cyclic poly(butylene terepthalate) oligomers (c‐PBT) and hydroxyl terminated bisphenols and hydroxylated siloxanes in the presence of a tin catalyst at a moderate temperature. The in situ copolymerization was conducted with various c‐PBT/tetrabromobisphenol A (TBBPA), bisphenol A diglycidyl ether (BPADGE) and Carbinol PDMS feed ratios respectively. The copolyesters were characterized by GPC, NMR, and DSC techniques. Pyrolysis‐combustion flow calorimeter (PCFC) and pyrolysis gas chromatography/mass spectrometry (PyGC/MS) studies were performed to characterize the fire retardant properties of the copolymers during combustion. POLYM. ENG. SCI., 47:1536–1543, 2007. © 2007 Society of Plastics Engineers
Comparative studies of ultra high molecular weight polyethylene fiber reinforced composites
Authors: Xu Tao , Farris Richard J. 
Published: September 2007

AbstractUltra high molecular weight polyethylene fiber is a very promising material for making light‐weight high strength and high impact resistant composites, especially for ballistic protective shields. Three commercially available materials designed specifically for ballistic applications are Spectra® woven cloth, Dyneema Fraglight® nonwoven felt, and Spectra Shield® Plus PCR prepreg were chosen for parallel comparisons. The high‐temperature high‐pressure sintering process was applied to all three materials. The physical, thermomechanical, and microstructural properties of the consolidated products were studied and compared, including their crystallinity, molecular orientation, impact resistance, interlaminar adhesion, flexural properties, and thermoformability. The differences in these materials and their structures are reflected in the different properties of the final products. The influence of different processing conditions on the properties also differs for each material. It is concluded that matrix free Spectra cloth composite has dominant advantages over the other two materials. POLYM. ENG. SCI., 47:1544–1553, 2007. © 2007 Society of Plastics Engineers
Influence from front contact sheet resistance on extracted diode parameters in CIGS solar cells
Authors: Malm Ulf , Edoff Marika 
Published: September 2007

AbstractThe extraction of one‐diode model parameters from a current–voltage (J–V) curve is problematic, since the model is one‐dimensional while real devices are indeed three‐dimensional. The parameters obtained by fitting the model curve to experimental data depend on how the current is collected, and more specifically the geometry of the contact. This is due to the non‐uniform lateral current flow in the window layers, which leads to different parts of the device experiencing different front contact voltage drop, and hence different operating points on the ideal J–V curve. In this work, finite element simulations of three‐dimensional contact structures are performed and compared to experimental data on Cu(In,Ga)Se2‐based solar cell devices. It is concluded that the lateral current flow can influence the extracted parameters from the one‐diode model significantly if the resistivity of the front contact material is high, or if there is no current collecting grid structure. These types of situations may appear in damp heat‐treated cells and module type cells, respectively. Copyright © 2007 John Wiley & Sons, Ltd.
Design and synthesis of a tribranched phenylethynyl‐terminated aryl ether compound and its use as a reactive diluent for PETI‐5
Authors: Rao Xianhua , Dang Guodong , Zhou Hongwei , Yang Wei , Cui Gang , Chen Chunhai , Yokota Rikio 
Published: September 2007

AbstractIn this study, a tribranched, phenylethynyl‐terminated aryl ether compound (Tri‐PE‐PAEK) was synthesized. This novel star‐shaped compound exhibits a good combination of properties, such as a low melting temperature (252 °C) and good solubility in aprotic solvents, as well as a low melt viscosity (0.1 P at 280 °C). All these advantages make it a good candidate material for modern processing techniques such as resin infusion and resin transfer molding, which are the most favorable methodologies for current economical manufacturing of polymer matrix/carbon fiber composites. Furthermore, after undergoing thermal curing to yield a network at 370 °C for 1 h, a cured sample exhibited an unexpectedly higher glass transition temperature (370 °C), storage modulus retention above the glass transition temperature, and good thermal stability. In addition, this compound can be used as a reactive diluent for phenylethynyl‐terminated imide oligomer, which has the molecular weight of 5000 g/mol (PETI‐5) to reduce its viscosity and lower the minimum temperature of the minimum viscosity. Meanwhile, the toughness of a cured blended resin can be greatly increased with the addition of just 10% Tri‐PE‐PAEK to PETI‐5. Further loading levels of Tri‐PE‐PAEK in the blending would lead to a higher storage modulus and a higher mechanical strength without compromising the thermal stability. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 4844–4854, 2007
Surface interaction of well‐defined, concentrated poly(2‐hydroxyethyl methacrylate) brushes with proteins
Authors: Yoshikawa Chiaki , Goto Atsushi , Tsujii Yoshinobu , Ishizuka Norio , Nakanishi Kazuki , Fukuda Takeshi 
Published: September 2007

AbstractThe interaction of concentrated polymer brushes with proteins was chromatographically investigated. By the use of surface‐initiated atom transfer radical polymerization, a low‐polydispersity poly(2‐hydroxyethyl methacrylate) (PHEMA) was densely grafted onto the inner surfaces of silica monoliths with mesopores of about 50 and 80 nm in mean size. The graft density reached 0.4–0.5 chains/nm2. The 80‐nm‐mesopore monolithic column with the concentrated PHEMA brush was characterized through the elution of low‐polydispersity pullulans with different molecular weights, clearly showing two modes of size exclusion, that is, one by the mesopores and the other by the brush phase. The latter mode gave a sharp separation with a critical molecular weight (size‐exclusion limit) of about 1000. This molecular size of pullulan was comparable to the distance between the nearest‐neighbor graft points. The elution behaviors of five proteins of different sizes (bovine serum thyroglobulin, bovine serum immunoglobulin G, bovine serum albumin, horse heart myoglobin, and bovine serum aprotinin) were studied with this PHEMA‐grafted column. The smallest protein, aprotinin, with a pullulan‐reduced molecular weight slightly larger than the critical value of 1000, was eluted much behind the corresponding pullulan, and this indicated that it barely got into the brush layer, suffering from a strong affinity interaction within the brush. On the other hand, the other four larger proteins were eluted at the same elution volumes as the equivalent pullulans, and this meant that they were perfectly excluded from the brush layer and separated only in the size‐exclusion mode by the mesopores without an affinity interaction with the brush surface. This excellent inertness of the concentrated brush in the interaction with the large proteins should afford the system long‐term stability against biofouling. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 4795–4803, 2007
Polymerization behaviors of racemic and chiral amphiphilic monomers in organized bilayer membranes of lamellar liquid crystalline phase
Authors: Chen Xinjiang , Matsuo Goh , Ohtani Bunsho , Tsujii Kaoru 
Published: September 2007

AbstractA racemic amphiphilic monomer, n‐dodecyl glyceryl itaconate (DGI), forms bilayer membranes in water in the presence of small amount of ionic cosurfactant and shows iridescent color. A chiral DGI, S‐DGI, also shows an iridescent property, but with a rather red shift in the color, which can be ascribed to the increased packing density of the monomer in the bilayer membranes. Chrial DGI has a more compact packing density than racemic one owing to closer distance between the monomer molecules; the conversion rate, however, is slower than that of racemic one when H2O2 is used as an initiator. When the initiator is changed to an amphiphilic one, 4‐(2‐hydroxyethoxy) phenyl‐(2‐hydroxy‐2‐propyl) ketone (Irgacure 2959), the chiral DGI shows even a little faster conversion rate than that of racemic one. The NMR chemical shift results of protons in benzene ring show that the molecules of Irgacure 2959 insert into the bilayer membranes. The molecular weights of the corresponding polymers prove that the initiation by H2O2 is restricted compared to that by Irgacure 2959. It is concluded that the decelerated polymerization behavior of chiral DGI initiated by H2O2 is a result of limited diffusion of the initiator into the lamellar bilayer structures. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 4891–4900, 2007
Solvent effects in the slow dynamics of proteins
Authors: Hinsen Konrad , Kneller Gerald R. 
Published: September 2007

AbstractThe influence of solvent on the slow internal dynamics of proteins is studied by comparing molecular dynamics simulations of solvated and unsolvated lysozyme. The dynamical trajectories are projected onto the protein's normal modes in order to obtain a separate analysis for each of the associated time scales. The results show that solvent effects are important for the slowest motions (below ≈ 1 ps−1) but negligible for faster motions. The damping effects seen in the latter show that the principal source of friction in protein dynamics is not the solvent, but the protein itself. Proteins 2008. © 2007 Wiley‐Liss, Inc.
The SKE‐DOCK server and human teams based on a combined method of shape complementarity and free energy estimation
Authors: Terashi Genki , Takeda‐Shitaka Mayuko , Kanou Kazuhiko , Iwadate Mitsuo , Takaya Daisuke , Umeyama Hideaki 
Published: September 2007

AbstractWe participated in rounds 6–12 of the critical assessment of predicted interaction (CAPRI) contest as the SKE‐DOCK server and human teams. The SKE‐DOCK server is based on simple geometry docking and a knowledge base scoring function. The procedure is summarized in the following three steps: (1) protein docking according to shape complementarity, (2) evaluating complex models, and (3) repacking side‐chain of models. The SKE‐DOCK server did not make use of biological information. On the other hand, the human team tried various intervention approaches. In this article, we describe in detail the processes of the SKE‐DOCK server, together with results and reasons for success and failure. Good predicted models were obtained for target 25 by both the SKE‐DOCK server and human teams. When the modeled receptor proteins were superimposed on the experimental structures, the smallest Ligand‐rmsd values corresponding to the rmsd between the model and experimental structures were 3.307 and 3.324 Å, respectively. Moreover, the two teams obtained 4 and 2 acceptable models for target 25. The overall result for both the SKE‐DOCK server and human teams was medium accuracy for one (Target 25) out of nine targets. Proteins 2007. © 2007 Wiley‐Liss, Inc.
Nanostructured thermoelectric oxides with low thermal conductivity
Authors: Weidenkaff A. , Robert R. , Aguirre M. H. , Bocher L. , Schlapbach L. 
Published: September 2007

AbstractComplex metal oxides, such as e.g. perovskite‐type phases are developed as potential functional materials to improve the efficiency of thermoelectric converters. Among those, cobaltates with p‐type conductivity and n‐type manganates are considered for the realisation of a ceramic thermoelectric converter. Sintered pellets with the composition AMO3–δ (A = Ln, RE; M = Co, Mn, Ni, Ti) and “Ca3Co4O9 derivates” were synthesized and characterised concerning their thermoelectric properties in a broad temperature range. It was found that the Seebeck coefficient and the electrical conductivity do not depend on the dimensions of the crystallites, while the heat conductivity can be substantially lowered by decreasing the size of the crystalline domains in these systems. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The impact of missing data and how it is handled on the rate of false‐positive results in drug development
Authors: Barnes Sunni A. , Mallinckrodt Craig H. , Lindborg Stacy R. , Carter M. Kallin 
Published: September 2007

AbstractIn drug development, a common choice for the primary analysis is to assess mean changes via analysis of (co)variance with missing data imputed by carrying the last or baseline observations forward (LOCF, BOCF). These approaches assume that data are missing completely at random (MCAR). Multiple imputation (MI) and likelihood‐based repeated measures (MMRM) are less restrictive as they assume data are missing at random (MAR). Nevertheless, LOCF and BOCF remain popular, perhaps because it is thought that the bias in these methods lead to protection against falsely concluding that a drug is more effective than the control. We conducted a simulation study that compared the rate of false positive results or regulatory risk error (RRE) from BOCF, LOCF, MI, and MMRM in 32 scenarios that were generated from a 25 full factorial arrangement with data missing due to a missing not at random (MNAR) mechanism. Both BOCF and LOCF inflated RRE were compared to MI and MMRM. In 12 of the 32 scenarios, BOCF yielded inflated RRE compared with eight scenarios for LOCF, three scenarios for MI and four scenarios for MMRM. In no situation did BOCF or LOCF provide adequate control of RRE when MI and MMRM did not. Both MI and MMRM are better choices than either BOCF or LOCF for the primary analysis. Copyright © 2007 John Wiley & Sons, Ltd.
Antiparkinson therapeutic potencies correlate with their affinities at dopamine D2High receptors
Authors: Seeman Philip 
Published: September 2007

AbstractTo determine whether antiparkinson dopamine agonists preferentially act on the high‐affinity or the low‐affinity states of dopamine D1 and D2 receptors, the agonist potencies were obtained by competition against [3H]SCH23390 for D1High and D1Low, and against [3H]domperidone for D2High and D2Low. N‐propylnorapomorphine and cabergoline were the most potent at D2High, with dissociation constants of 0.18 and 0.36 nM, respectively. Other agonists had D2HighKi values of 0.52 nM for quinagolide, 0.6 nM for (+)PHNO, 0.9 for bromocriptine, 1.8 nM for apomorphine, 2.4 nM for pergolide, 3 nM for quinpirole, and 6.2 nM for lergotrile. There was a clear correlation between the Ki values at D2High and their therapeutic concentrations in the plasma water, as derived from the known concentrations after correction for the fraction bound to the human plasma proteins. The data suggest that D2High is the primary and common target for the antiparkinson action of dopamine agonists. Bromocriptine, cabergoline, lergotrile, pergolide, and pramipexole had no affinity for D1High, consistent with the clinical observations that the D2‐selective bromocriptine and pramipexole elicit low levels of dyskinesia. Synapse 61:1013–1018, 2007. © 2007 Wiley‐Liss, Inc.