bluuebunny/crossref_metadata_2025_split huggingface dataset:
Oculo-Visual Findings among Industrial Mine Workers at Goldfields Ghana Limited, Tarkwa
Authors: Ovenseri-Ogbomo GO , Ocansey S , Abu EK , Kyei S , Boadi-Kusi SB 
Published: April 2012

Objective The focus of this study was to evaluate the visual status of mine workers who were directly involved in mining and/or are exposed to the mining environment. Methods A hospital based cross-sectional study was conducted. Four hundred and six (406) workers were conveniently sampled for the study. Information on their socio-demographic data was also collected. In addition, all participants underwent ophthalmic examination. Results The mean age of the workers was 41.1 years. Visual impairment was found in 114 (28.1%) of the study population of which refractive error (56.8%) was the major cause. Presbyopia was also observed in 45.5% of the workers with only 30.3% of them wearing near correction. The prevalence of eye diseases were pterygium/pingueculae (25.8%), conjunctivitis (26.8%), suspected glaucoma (15.3%), and cataract (7.4%). Conclusions Visual impairment and eye diseases were found among the miners.
Large Fibroid arising from Mullerian Remnant Mimicking as Ovarian Neoplasm in a Woman with MRKH Syndrome
Authors: Chakravarty Baidyanath , Singh Soma , Chakravarty Manju , Chakravarty Astha 
Published: April 2012

ABSTRACTIn this article, a large leiomyoma with degenerative changes arising from the rudimentary uterine knob in a patient with Mayer- Rokitansky-Kuster-Hauser (MRKH) syndrome and mimicking an ovarian neoplasm is reported.The patient was a 39-year-old woman, known case of MRKH with vaginal aplasia who presented with pain abdomen, loss of appetite and weight. On physical examination, a large pelvic mass was detected. A provisional diagnosis of left ovarian neoplasm was made on USG and CT scan for which an exploratory laparotomy was performed. Finally, it was diagnosed as a case of multiple leiomyomas with hyaline degeneration on histopathological examination.Myoma arising from a rudimentary uterine knob/anlage is a rare finding but should be considered in the differential diagnosis of pelvic mass in patients with MRKH syndrome.How to cite this articleSingh S, Chakravarty B, Chakravarty M, Chakravarty A. Large Fibroid arising from Mullerian Remnant Mimicking as Ovarian Neoplasm in a Woman with MRKH Syndrome. Int J Infertility Fetal Med 2012;3(1):30-32.
The Influence of the Specification of Climate Change Damages on the Social Cost of Carbon
Authors: Kopp Robert E. , Golub Alexander , Keohane Nathaniel O. , Onda Chikara 
Published: April 2012

Abstract
Drawing upon climate change damage specifications previously proposed in the literature that the authors have calibrated to a common level of damages at 2.5°C, the authors examine the effect upon the social cost of carbon (SCC) of varying damage specifications in a DICE-like integrated assessment model. They find that SCC estimates are highly sensitive to uncertainty in extrapolating damages to high temperatures at moderate-to-high levels of risk aversion, but only modestly so at low levels of risk aversion. While in the absence of risk aversion, all of the SCC estimates but one agree within a factor of two, with a moderate level of risk aversion included, the differences among estimates grow greatly. For example, one composite damage specification, combining elements of different literature-derived specifications and roughly taking into account calibration uncertainty, yields SCC values 32% higher than the standard quadratic DICE damage function in the absence of risk aversion. With a coefficient of relative risk aversion of 1.4, however, the same uncertain specification yields SCC values almost triple those of the standard function. The authors conclude that failure to consider damages uncertainty and risk aversion jointly can lead to significant underestimation of the SCC.
Reducing the Fuel Cost of Motor Carriers by Using Optimal Routing and Refueling Policies
Authors: Suzuki Yoshinori , Dai Jing 
Published: April 2012

AbstractFuel optimizers are decision models (software products) that are increasingly recognized as effective fuel-management tools by US truckload carriers. Given the origin and the destination of a particular load, these software products seek both the route to use from origin to destination and the sequence of truck stops to use along the route so as to minimize the fuel cost of operating a vehicle. While useful, these products currently provide limited benefits to the users because they all use heuristic methods. Exact (optimal) methods are available in the academic literature, but they are not yet used in practice mainly because they lack empirical support. This article fills this gap in the literature by conducting an empirical analysis that contrasts the effectiveness of the conventional heuristic method and the emerging exact methods. Computational testing with real-world instances shows that the exact method attains noticeable cost savings over the heuristic method without significantly increasing the computational time.
Effect of Processing on Microstructure and Physical Properties of Three Nickel‐Based Superalloys with Different Hardening Mechanisms
Authors: Strondl Annika , Milenkovic Srdjan , Schneider André , Klement Uta , Frommeyer Georg 
Published: April 2012

AbstractThe nickel‐based superalloys Inconel alloy 600, Udimet alloy 720, and Inconel alloy 718 were produced by electron beam melting (EBM), casting, and directional solidification (DS). The distance between dendrites and the size of the precipitates indicated the difference in solidification rates between the three processes. In this study, the solidification rate was fastest with EBM, closely followed by casting, whereas it was much slower with DS. In the directional solidified materials the <100> direction was the fastest and thus, preferred growth direction. The EBM samples show a sharp (001)[100] texture in the building direction and in the two scanning directions of the electron beam. Macrosegregation was observed in some cast and directionally solidified samples, but not in the EBM samples. The melting temperatures are in good agreement with literature and the narrow melting interval of IN600 compare to UD720 and IN718 might reduce the risk of incipient melting during EBM processing. Porosity was observed in the EBM samples and the reasons are discussed. However, EBM seems to be a feasible process route to produce nickel‐based superalloys with well‐defined texture, no macrosegregation and a rapidly solidified microstructure.
Graphite Oxide as an Olefin Polymerization Carbocatalyst: Applications in Electrochemical Double Layer Capacitors
Authors: Dreyer Daniel R. , Bielawski Christopher W. 
Published: April 2012

AbstractGraphite oxide (GO) is shown to be an efficient heterogeneous catalyst for the polymerization of various olefin monomers, including n‐butyl vinyl ether, N‐vinylcarbazole, styrene, and sodium 4‐styrenesulfonate. The GO‐catalyzed polymerization of n‐butyl vinyl ether (0.1–5.0 wt% GO relative to monomer) proceeds rapidly under solvent‐free conditions and affords polymers with moderate number average molecular weights and broad polydispersities. Analysis of the carbon recovered at the conclusion of the polymerization reactions reveals that the material's catalytic activity is retained and multiple polymerization cycles can be performed without regenerating the catalyst. GO also catalyzes the polymerization of N‐vinylcarbazole and styrene, although only low molecular weight polymers are obtained. Sodium 4‐styrenesulfonate polymerizes in the presence of GO to afford poly(sodium 4‐styrenesulfonate) (PSS) composites. After thermal treatment, the composites can be fabricated into electrodes for use in electrochemical double layer capacitors (EDLCs). The devices display high specific capacitances (25–120 F g−1) and low equivalent series resistances (14–27 Ω).
Minimizing Energy Losses in Dye‐Sensitized Solar Cells Using Coordination Compounds as Alternative Redox Mediators Coupled with Appropriate Organic Dyes
Authors: Stergiopoulos Thomas , Falaras Polycarpos 
Published: April 2012

AbstractTo further boost the efficiency of dye‐sensitized solar cells, a correct evaluation of the real limitations of this type of solar cell should be conducted. From a simple analysis of the photovoltaic data found in the literature, it is evident that the Voc decrease, through energy losses, seems to be the most crucial factor diminishing the overall system efficiency. In particular, losses arising from the regeneration of the dye by the iodide/triiodide redox mediator are huge. The most convenient manner to recuperate these losses is the use of alternative redox mediators with more positive redox potentials than that of the iodide‐based shuttle. Among various types of redox active compounds, ferrocene/ferrocenium, Cu+/2+, and Co2+/3+ complexes are found to be the most effective in solar cells and the obtained efficiencies of more than 12% clearly show that a breakthrough is close, paving revolutionary roads towards making new records.
Influence of calcium carbonate filler and mixing type process on structure and properties of styrene–acrylonitrile/ethylene–propylene–diene polymer blends
Authors: Krehula Ljerka Kratofil , Siročić Anita Ptiček , Katančić Zvonimir , Jelenčić Jasenka , Kovačević Vera , Hrnjak‐Murgić Zlata 
Published: April 2012

AbstractThe properties of styrene–acrylonitrile (SAN) and ethylene–propylene–diene (EPDM) blends containing different types of calcium carbonate filler were studied. The influence of mixing type process on the blend properties was also studied. Two different mixing processes were used. The first one includes mixing of all components together. The other process is a two‐step mixing procedure: masterbatch (MB; EPDM/SAN/filler blend) was prepared and then it was mixed with previously prepared polymer blend. Surface energy of samples was determined to predict the strength of interactions between polymer blend components and used fillers. The phase morphology of blends and their thermal and mechanical properties were studied. From the results, it can be concluded that the type of mixing process has a strong influence on the morphological, thermal, and mechanical properties of blends. The two‐step mixing process causes better dispersion of fillers in blends as well as better dispersion of EPDM in SAN matrix, and therefore, the finest morphology and improved properties are observed in blends with MB. It can be concluded that the type of mixing process and carefully chosen compatibilizer are the important factors for obtaining the improved compatibility of SAN/EPDM blends. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Aqueous carbon black dispersions prepared with steam‐jet‐cooked corn starch
Authors: Kenar James A. , Felker Frederick C. , Fanta George F. 
Published: April 2012

AbstractThe utilization of jet‐cooked waxy and normal corn starch to prepare aqueous dispersions of hydrophobic carbon black (CB; Vulcan XC‐72R) is reported. Blending into aqueous jet‐cooked dispersions of starch followed by high‐pressure homogenization produced stable aqueous CB dispersions. The dispersed CB particles were shown to have starch adsorbed onto their particle surfaces. The adsorbed starch imparted hydrophilic properties to the CB, and after extensive washing to remove dissolved and loosely bound starch, the CB particles remained well dispersed in water. Thermogravimetric analysis, Fourier transform infrared spectroscopy, acid and enzymic starch digestion experiments, and microscopy (light and transmission electron microscopy) were used to characterize the starch‐coated CB particles. The method described herein demonstrates a simple, effective, and environmentally friendly method for preparing aqueous CB dispersions. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Ionic liquid‐catalyzed aminolysis of poly(ethylene terephthalate) waste
Authors: Palekar Vikrant S. , Shah Rikhil V. , Shukla S. R. 
Published: April 2012

AbstractAminolytic depolymerization of poly(ethylene terephthalate) (PET) bottle waste with ethanolamine and hydrazine hydrate under atmospheric conditions was investigated in the presence of room temperature ionic liquids. 1‐Hexyl‐3‐methylimidazolium trifluoromethanesulfonate (Hmim.TfO) and 1‐butyl‐3‐methylimidazolium hydrogen sulfate (Bmim.HSO4). (Hmim.TfO) was found to be the most efficient catalyst to obtain high yields of the aminolysis products bis(2‐hydroxy ethylene) terephthalamide and terephthalic dihydrazide using ethanolamine and hydrazine hydrate, respectively. These products were characterized by IR spectroscopy, 1H NMR, 13C NMR, mass spectroscopy, and differential scanning calorimetry. The influence of experimental parameters, such as the amount of catalyst, reaction time, molar ratio of ethanolamine, and hydrazine hydrate with respect to PET was investigated. This protocol proves to be efficient and environmentally benign in terms of high yields (>84%) and low reaction times (up to 30 min). © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Synthesis, characterization, and thermal degradation kinetic of polystyrene‐g‐polycaprolactone
Authors: Yildirim Yeliz , Doğan Buket , Muğlali Sinem , Saltan Fehmi , Özkan Melek , Akat Hakan 
Published: April 2012

AbstractIn the present study, it has been demonstrated that polystyrene‐g‐polycaprolactone (PS‐g‐PCL) was successfully prepared by “click chemistry.” For this purpose, first, poly(styrene‐co‐4‐chloromethylstyrene) (P(S‐co‐CMS)) with 4‐chloromethylstyrene content (10%) was synthesized. Second, alkyne‐functionalized polycaprolactone (PCL) was obtained using propargyl alcohol and caprolactone. P(S‐co‐CMS) and PCL were reacted in N,N‐dimethylformamide for 24 h at 25°C to give PS‐g‐PCL. The synthesized polymer was characterized by nuclear magnetic resonance (1H‐NMR), gel permeation chromatography, Fourier transform infrared spectroscopy and thermogravimetric analysis. The apparent activation energies for thermal degradation of PS‐g‐PCL were obtained by differential (Kissenger) and integral methods (Flynn–Wall–Ozawa, Kissinger–Akahira–Sunose, Tang, Coats–Redfern, Van Krevelen et al.). The decomposition mechanism and pre‐exponential factor were calculated in terms of Coats–Redfern method. The most likely decomposition processes of first and second degradation stages were An type and F3 type, respectively. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Crosslinking of poly(vinyl acetate) nanolatices by gamma and UV radiation
Authors: Meléndez‐Ortiz Iván , Flores‐Martínez Raúl , Bucio Emilio , Cortez‐Mazatán Gladis , Martínez‐Gutiérrez Hugo , Peralta René D. 
Published: April 2012

AbstractPoly(vinyl acetate) PVAc, in nanolatices with 10% polymer content, prepared by microemulsion polymerization was crosslinked by gamma and UV radiation. PVAc colloidal nanoparticles (average diameter, Dp = 58 nm) had Mw = 562,000 g/mol and about 95% conversions. PVAc nanolatices irradiated by gamma rays (1–13 kGy) at room temperature without crosslinking agent and by UV light (30–300 s exposure times) in the presence of divinylbenzene and allyl methacrylate showed crosslinking of up to 96% (high gel content), Dp < 100 nm and did not degrade as shown by FTIR spectroscopy. DSC and TGA characterization of irradiated PVAc samples indicated that Tg temperatures increased from 28°C for PVAc to 42°C and 39°C for UV and gamma rays crosslinked PVAc, respectively, whereas 10% weight losses occurred at 261°C for uncrosslinked PVAc and at 320 and 313°C for UV and gamma rays crosslinked PVAc. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Synthesis of Bis(1H, 1H, 2H, 2H‐perfluoro‐octyl)methylenesuccinate copolymers and their application on cotton fabrics
Authors: Ye Haohua , Li Zhanxiong , Chen Guoqiang , Fan Dan 
Published: April 2012

AbstractBis(1H, 1H, 2H, 2H‐perfluoro‐octyl)methylenesuccinate (FOM)/ethyl acrylate (EA)/methyl methacrylate (MMA) copolymer (FOME) latexes, FOM/butyl acrylate (BA)/MMA copolymer (FOMB) latexes, and FOM/octyl acrylate (OA)/MMA copolymer (FOMO) latexes were synthesized by continuous emulsion polymerization. Solution polymerization was also carried out to prepare FOMB. The influences of fluorine content and curing conditions on the surface properties of polymer films were discussed. The water and oil repellency of cotton fabrics treated with the FOM copolymers was better than that of conventional poly(fluoroalkyl acrylate)s containing the same fluorinated chain. The polymer films or the treated fabrics were characterized by Fourier transform infrared, scanning electron microscope, atomic force microscopy, thermogravimetric analysis, x‐ray photoelectron spectrometry, and wide angle x‐ray diffraction. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci, 2013
Structure and rheology of polyethylene/imidazolium‐based montmorillonite nanocomposites
Authors: Médéric P. , Le Pluart L. , Aubry T. , Madec P.‐J. 
Published: April 2012

AbstractIn this study, nanocomposites based on linear low density polyethylene (PE) and organomodified montmorillonites (MMTs) have been processed without adding any other polar compatibilizer such as maleic anhydride grafted PE. We evidence the beneficial effect on the state of dispersion of an imidazolium‐based MMT compared to traditional commercial organoclays, one of which being its alkylammonium equivalent. Transmission electron microscopy observations and melt rheology are used to characterize the state of dispersion of clay in the polymer matrix. Thinner primary particles and lower interparticle distances are obtained with the imidazolium‐based MMT. This result is attributed to a higher initial gallery spacing which favors delamination phenomena. As a consequence, the dispersion state of this organoclay is much more sensitive to changes in the mixing shear rate, contrarily to the commercial ones. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Improving the mechanical properties of isosorbide copolycarbonates by varying the ratio of comonomers
Authors: Lee Chi‐Han , Takagi Hideki , Okamoto Hirotaka , Kato Makoto 
Published: April 2012

AbstractPolycarbonates were synthesized by transesterification polymerization of isosorbide, bisphenol A, and diphenyl carbonate in the presence of n‐BuSn(O)OH as the catalyst. The polymers were prepared by varying the ratio of the two monomers. The polymers exhibited good thermal stability, rigidity, and strength. The storage moduli for the polymers were 2.6 to 3.2 GPa at 25°C and increased with increasing isosorbide content. The dynamic mechanical analysis indicated that the storage moduli (E′) of the polymers are constant to higher temperatures than that of bisphenol A polycarbonate. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Application of block copolymeric surface modifier with crosslinkable units for montmorillonite nanocomposites
Authors: Uyen Nguyen Thai Ngoc , Joo Sang Il , Kim Won Ho , Oh Myung Hwan , Lee Jonghwi , Lim Bum Soon , Hong Sung Chul 
Published: April 2012

AbstractMontmorillonite (MMT) of which the surface was modified with a block copolymer with crosslinkable units was incorporated into methacrylate‐based composites as nanofiller to improve dimensional and mechanical properties. A bifunctional block copolymer containing 2‐isocyanato ethyl methacrylate in one block and poly(vinyl pyridine) units in the other block was prepared as the block copolymeric surface modifier for MMT through controlled/“living” radical polymerization technique. Application of the modified MMT in 2,2‐bis[4‐(2‐hydroxy‐3‐methacryloyl‐oxy)phenyl]propane (bis‐GMA) based composites showed that polymerization shrinkages of the composites decreased as the content of modified MMT increased. Compressive and flexural strengths of the composites were also improved in the presence of the modified MMT, which demonstrate the beneficial effect of the modified MMT as a nanofiller and IEM as a cocrosslinkable unit. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Dynamic mechanical and thermal properties of the composites of thermoplastic starch and lanthanum hydroxide nanoparticles
Authors: Ochigbo Stephen S. , Adriaan S. Luyt  , Mofokeng Julia P. , Antić Željka , Dramićanin Miroslav D. , Djoković Vladimir 
Published: April 2012

AbstractNanostructured lanthanum (III)‐oxide (La2O3) particles were prepared by a polymer complex solution method and further used for the preparation of lanthanum hydroxide (La(OH)3) nanoparticles. The La(OH)3 nanopowder was mixed with glycerol‐plasticized maize starch and the effect of the filler on the thermal, mechanical, and viscoelastic properties of the matrix was investigated. It was expected that this nanofiller, which shows an affinity toward OH groups, would strongly affect the physical properties of thermoplastic starch (TPS). The pure TPS and the TPS‐La(OH)3 nanocomposite films (with 1, 2, and 3 wt % filler) were conditioned at various relative humidities (RHs) (35, 57, 75, and 99% RH). After conditioning at 99% RH, the pure TPS films exhibited higher affinity toward water than the nanocomposites. Differential scanning calorimetric measurements showed that, due to retrogradation effects, the melting enthalpies of the films increased with increasing RH. Dynamic mechanical analysis revealed that the mechanical properties in the linear range strongly depend on both the humidity conditions and the concentration of the filler. The results also show that La(OH)3 nanoparticles are good reinforcement for TPS films. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Enhancement of polylactide nucleation by montmorillonites intercalated with a green seaweed byproduct
Authors: Fordiani Fabrizio , Aubry Thierry , Pillin Isabelle , Grohens Yves 
Published: April 2012

AbstractPolylactide (PLA) nanocomposites with improved mechanical and barrier properties are of growing industrial interest and therefore required green modified montmorillonites (gm‐MMTs) to meet the expectation of totally biosourced material. In this study, ulvans that are polysaccharides and glycoproteins extracted from seaweed are used as surfactants to achieve intercalated clays. The effect of this gm‐MMT (ALL350) on the crystallization kinetics of PLA was compared to Cloisite 30B, and pristine MMT was taken as a reference. Rheology, differential scanning calorimetry, and transmission electronic microscopy experiments were performed to better understand the effects that dominate the so‐called nucleating effect observed in PLA nanocomposites. It was found that two major driving forces explain the efficiency of the ALL350 that enhances PLA nucleation. The first one is the decrease of the interfacial energy and the second is a reduction of the complex viscosity that acts on the induction period. Reduction of both the interfacial energy and the surface friction forces between PLA chains and polysaccharides‐treated clay platelets is assumed to facilitate the induction process. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013