bluuebunny/crossref_metadata_2025 huggingface dataset:
Film Morphology and Electroluminescence of Poly[9,9-di-(2'-ethylhexyl) fuorenyl-2,7-diyl] Blended with a Hole Transporting Polymer
Authors: Zhang Qiushu
Published: September 2018

This paper reports on the phase-separated film morphology and electroluminescence (EL) of a polyfluorene, poly[9,9-di-(2'-ethylhexyl)fluorenyl-2,7-diyl], blended with the hole transport material, poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(N,N'-bis(4-butylphenyl-1,1'-biphenylene-4,4'-diamine))]. The film morphology changes remarkably with the blend ratio. Other factors like polymer solution concentration, substrate and film thickness could also influence the film morphology. The addition of the hole-transporting polymer to the host polymer improved device properties of light-emitting diodes (LEDs). The maximum luminance achieved was 884 cd/m2. The maximum external quantum efficiency of the blended polyfluorene devices was 0.1%, which is more than three times higher than that of the pristine polyfluorene LEDs. The introduction of the hole-transporting polymer also modifies the EL spectrum. For the blend-based devices, the EL peaked at 504 nm, having a blue shift of 33 nm compared to that of the single polymer based devices. Phase-separated domains, or interactions at their interfaces, may play a role in the improved device performance.
Liquid Silicone Rubber Vulcanizates: Network Structure - Property Relationship and Cure Kinetics
Authors: Rajesh G. , Maji Pradip K. , Bhattacharya Mithun , Choudhury Anusuya , Roy Nabarun , Saxena Anubhav , Bhowmick Anil K.
Published: September 2018

Liquid silicone rubber (LSR) vulcanizates have been prepared from vinyl-end capped polydimethylsiloxane (PDMS) and polymethylhydrogenosiloxane (PMHS) in presence of platinum catalyst using solution casting technique. The science involving synthesis of usable silicone rubber by curing with polymethylhydrogenosiloxane has been studied in details. The effects of vinyl content of PDMS and the ratio of hydride crosslinker to vinyl concentration on crosslink density, mechanical, dynamic-mechanical and thermal properties have been discussed. It has been found that at optimum level of crosslinker, the LSR vulcanizate shows a maximum crosslink density with highest improvement in mechanical and thermal properties. The amount of crosslinker required, depends upon the number of vinyl functionality per unit length of the polymer chain and the chemical composition of the hydride crosslinker. This study makes a novel attempt to determine cure kinetics of PDMS by using Fourier Transform Infrared spectroscopy. Measurements have been done at three different temperatures and found to follow the first order reaction with respect to consumption of vinyl (C=C) and silyl hydride groups (Si-H). The activation energy and kinetic parameters have been determined as well.
Preparation and Characterization of PBMA/SiO2-TiO2 Hybrid Fibres
Authors: Ma Haihong , Shi Tiejun
Published: September 2018

Silica-titania (SiO2-TiO2) blend sols were prepared via a sol-gel method from tetraethoxylsilane and tetrabutyl titanate. Poly(butyl methacrylate) (PBMA)/SiO2-TiO2hybrid sols were synthesized through in-situ polymerization of butyl methacrylate (BMA) in the blend sol. After ageing treatment, PBMA/SiO2-TiO2 hybrid fibres were prepared by drawing from the hybrid sol. The mechanism of the hybrid reaction was studied carefully. The hybrid fibres were characterized by Fourier transform infrared (FT-IR) spectrometry, scanning electron microscopy (SEM), High-resolution transmission electron microscopy (HRTEM), Fluorescence Spectrophotometry (FL), Ultraviolet Visible Spectrometry (UV-Vis) and Thermogravimetric Analysis (TGA). FT-TR results suggested that PBMA was linked to SiO2-TiO2 network through chemical bonds. SEM measurements indicated that the diameter of the fibres was about 50 μ m, and the whole system was homogeneous. HRTEM images showed that the dimensions of the organic phase were about 50 nm, and the distributions of the organic phase were not very uniform. FL and UV-Vis measurements confirm the fluorescence of the hybrid fibres with improved shielding to UV TGA measurements suggest that the hybrid fibres show better resistance to heat than pure PBMA.
Plasma Treatment and its Effects on the Tribological Behaviour of Basalt/Epoxy Woven Composites in a Marine Environment
Authors: Kim M.H. , Rhee K.Y. , Park S.J.
Published: September 2018

Interfacial debonding at the fibre/matrix interface is known to cause the critical fracture of fibre-reinforced polymer composites (FRPs). Especially in a marine environment, the bonding between fibre and matrix is easily weakened by moisture absorption.

In this study, a basalt woven fabric was surface-treated by atmospheric oxygen plasma to improve adhesive force at the fibre/matrix interface and its effects on the wear properties of a basalt/epoxy woven composite in a marine environment were investigated. Ball-on-disk wear tests were performed and scanning electron microscopy (SEM) was used to analyze the wear track. The results indicated that oxygen plasma treatment of a basalt fibre reduced moisture diffusion in basalt/epoxy woven composites; while an untreated specimen took 30 days to reach maximum moisture content, similar moisture content was only observed in the oxygen plasma treated specimen after 40 days. In addition, oxygen plasma treatment of a basalt fibre improved the wear properties of the basalt/epoxy woven composite, and the wear volume of the basalt/epoxy woven composite (prior to moisture absorption) was reduced from 2.95 mm3 to 0.65 mm3. The surface treatment also appeared to cause an increase in the interfacial adhesion between the fibre and resin, thus reducing the debonding of basalt fibres on the wear surface.
Preparation of Low Molecular Weight Polyvinyl alcohol)/Montmorillonite Composite Nanoparticles Using an Electrospraying Technique
Authors: Park Sung Min , Park Jae Hyeung , Islam Md. Shahidul , Choi Jin Hyun , Ghim Han Do , Yoon Nam Sik , Yeum Jeong Hyun
Published: September 2018

Composite nanoparticles composed of low molecular weight poly(vinyl alcohol) (LMW-PVA) and montmorillonite (MMT) were prepared using the electrospraying technique by regulating PVA solution concentration. Field-emission type scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, reflection type X-ray diffraction and thermal gravimetric analysis were utilized to characterize the LMW-PVA/MMT composite nanoparticles morphology and properties. MMT platelets were exfoliated and well distributed within the composite nanoparticles. It was also found that the thermal stability was enhanced by the addition of MMT.
Effect of Injection Slot Location on Die-Detached Tapered Injection Chamber in Resin Injection Pultrusion
Authors: Jeswani A.L. , Roux J.A.
Published: September 2018

This study seeks to continuously improve the wetout and thus the quality and productivity of pultruded parts for the tapered injection pultrusion process for an injection chamber “detached” from the pultrusion die. Complete wetout of the dry fibre reinforcement by the liquid resin depends strongly on the axial location of the injection slot within the injection chamber. This investigation was conducted for a high pull speed with a fibre volume fraction and resin viscosity for a nominal polyester/glass roving composite. A 3-D finite volume technique was developed to simulate the flow of polyester resin through the glass rovings. The results show the impact of the axial location of the injection slot on the minimum injection pressure necessary to achieve complete fibre matrix wetout and the resin pressure within the injection chamber for a tapered injection chamber which is “detached” upstream of the pultrusion die. Injection chamber design information is presented.
Characterization and Modelling of Hygrothermal Effects in Thermoplastic Nanocomposites
Authors: Roy Samit , Narasimhan Kameshwaran
Published: September 2018

The hygrothermal and mechanical characterization of continuous fiber-reinforced nanocomposites in compression molded E-Glass fiber-reinforced in polyamide-6 or nylon-6 matrix with and without different weight addition of nanoclay have been performed. E-Glass/Nylon-6 nanocomposite was characterized by means of X-Ray Diffraction to determine the nanoclay dispersion morphology. Significant improvement were achieved in compressive strength, shear strength and barrier properties with relatively low nanoclay loadings. The baseline and nanoclay modified E-Glass/Nylon-6 specimens were immersed in de-ionized water at 50 °C and aged hygrothermally. Mechanical tests on unaged E-Glass/Nylon-6 nanocomposite confirmed strength enhancement with nanoclay addition, with a significant improvement in compressive strength (50% at 4 wt.% nanoclay loading) and shear strength (~36% at 4 wt.% nanoclay loading). Mechanical tests on hygrothermally aged E-Glass/Nylon-6 modified with 4 wt.% nanoclay loading showed that hydrothermal degradation is drastically reduced with a significant reduction (~30%) in moisture uptake compared to baseline E-Glass/Nylon-6 composites. An analytical model is developed to capture the diffusion mechanism and attribute the change in diffusivity and moisture uptake with weight addition of nanoclay to tortuosity and reduction in free volume created by the presence of nanoclay. The loss in change in free volume computed using Atomic Force Microscopy images is compared with analytical model.
The Mechanical Behaviour and Failure Mode of FRP Composite Steel Casing Joints
Authors: Wang Zhen-shan , Ma Xiao-ming , Liu Yun-he , Hui MA , Guo Hong-chao
Published: September 2018

Fibre reinforced plastic (FRP) composite has been widely used in engineering due to its light weight, high strength, and corrosion resistance. Joint behaviour is important in structural design. This research investigated the ultimate tensile and compressive bearing capacities of bonding joints of Φ200 mm x 10 mm steel casing. By conducting full-scale tests, the load-displacement curve and strain distribution in joints in an FRP composite steel casing were analysed, and the ultimate bearing capacity, stiffness, and failure mode were obtained. The research showed that under axial compression, joints underwent brittle failure, and the steel casing exerted a greater lateral restraint to the composite pipe, which resulted in a decrease of bearing capacity of its components. While under axial tension, the failure mode of joints was such that the FRP composite pipe was pulled off and the bearing capacity of its joints was determined by the strength of the binders used. This study forms an experimental basis for engineering application.
Erosion Resistance and Interface Properties of Epoxy Composite Filled with Graded Silicon Carbide
Authors: Zhang Yaming , Zhang Haihong , Yang Jianfeng , Geng Gangqiang
Published: September 2018

In the present study, the effect of graded aggregate on the erosion resistance and interface performance of SiC/EP (epoxy resin) composite was investigated. The graded aggregate (84% 550μm and 16% 110 μm) SiC particles was designed by the modified coarse aggregate void filling approach from the theory of concrete. The erosion mechanism of obtained composite was discussed through the microstructure analysis. Obtained results from different erosion tests showed the graded structure contributed to increasing the hard spots and density, which significantly reduced erosion rate. The mechanical properties and wear fraction indicated that the preferred interface could be obtained using migration with KH-550.
Morphology and Thermal Property of Poly(L-Lactide)/Layered Double Hydroxides Nanocomposites via Melt Intercalation
Authors: Tang Mengqi , Qi Fei , Chen Man , Xu Yang , Li Huan , Chen Xiaolang , Qin Jun , Guo Shaoyun , Shen Ru
Published: September 2018

In this work, sodium dodecyl sulfate (SDS) was used to obtain organically-modified layered double hydroxide (OMgAl-LDH) by anion-exchange reaction. The PLLA/LDH nanocomposites were prepared via direct melt intercalation. The results from both XRD patterns and FTIR spectra showed that SDS entered into the layers of LDH successfully and the layer space was increased from 0.756 to 1.64 nm. For the PLLA/LDH nanocomposites, the increase of the layer space was verified by the good dispersion of LDH in the PLLA matrix from the SEM images. The rheological analysis showed that the typical Newtonian behaviour shifted to shear-thinning behaviour with the addition of LDH. In addition, DSC data illustrated that the glass transition temperature of the PLLA/LDH nanocomposites decreased and the crystallinity of PLLA increased due to the addition of LDH, which indicates that LDH acts as a heterogeneous nucleating agent and induces the crystallization of PLLA. The modified LDH provided a better nucleating effect than the unmodified LDH. TGA results showed that OMgAl-LDH in the PLLA matrix caused earlier initial decomposition, suggesting that the presence of LDH decreased the thermal stability of the PLLA matrix.
Processing Routes for the Preparation of Poly(Lactic Acid)/Cellulose-Nanowhisker Nanocomposites for Packaging Applications
Authors: Moran Juan I. , Ludueña Leandro N. , Phuong Vu Thanh , Cinelli Patrizia , Lazzeri Andrea , Alvarez Vera A.
Published: September 2018

In this work, poly(lactic acid) (PLA)/cellulose-nanowhisker (CNW) nanocomposites were prepared by twin-screw extrusion followed by injection moulding. The CNW was dispersed in a plasticizer/compatibilizer (PL) before the melt mixing process. It was found that the PL not only improved the processability and reduced the fragility of PLA but also prevented the agglomeration of the CNW up to 12 wt.% of CNW content, obtaining well dispersed and distributed PLA/CNW nanocomposites. The prepared nanocomposites were injection-moulded and their mechanical/thermal properties were evaluated. PLA/CNW nanocomposites showed better mechanical properties than those of the neat matrix but the material with the lower CNW content showed the best mechanical performance.
Clay/Polyethylene Composites with Enhanced Barrier Properties for Seed Storage
Authors: Hu Lei , Leclair Έric , Poulin Mado , Colas Fabienne , Baldet Patrick , Vuillaume Pascal Y.
Published: September 2018

The utilization of clays to enhance the water vapour barrier properties of polyethylene requires knowledge about factors associated with the constituents themselves. Hence, this paper presents combinations of two types of polyethylene and five different clays. Morphological, mechanical and thermal properties related to the water vapour permeability of clay/polyethylene composites were investigated. Although no evidence of clay exfoliation was observed according to morphological and spectral results, it was found that the enhanced water vapour barrier properties were linked to clay aspect ratio, composites interface, polyethylene crystallinity and storage conditions. The best water vapour barrier properties were obtained by increasing polyethylene crystallinity with unmodified clay of high aspect ratio. Organoclays addition showed no improvement in barrier properties of polyethylene unless the interface was strongly compatibilized. Contrary to the results published elsewhere, clay addition brought about no mechanical improvements to polyethylene tested.
Empirical Modeling and Experimental Investigation of the Amine Treated Nanoclay Reinforced Epoxy-Polyurethane Blended Resin Composites
Authors: Athimoolam M. , Moorthy T.V. , Sureshbabu A.
Published: September 2018

Mechanical properties of nanoclay filled epoxy-polyurethane blended resins were experimentally investigated as they are proved to be very good materials for shape memory applications such as actuators, water and oil pipelines and aircrafts components like bearings, valve seat and floor etc. The mechanical properties such as tensile strength, compressive strength, flexural strength, shear strength etc. are become poor when the shape memory properties such as strain rate, strain recovery rate and strain fixidity ratio are good in polyurethane based nanocomposites. Therefore, polyurethane blended with epoxy is prepared as it is exhibiting interpenetrating network and the nanoclay is reinforced to improve the mechanical as well as functional properties. Therefore, there is absolute necessity for process modeling and parameter modeling of these materials in order to arrive at the optimum composition to have better mechanical properties. Mathematical modeling and empirical modeling are the effective ways for cost reduction methodology and stepping-stone to do optimization of the process parameters and properties of the materials developed. This paper initially analyses glass transition temperature and degradation temperatures by Differential Scanning Calorimetry. Then the different empirical model results are discussed for the selecting a suitable model and a simplified approach to analyse the mechanical properties of randomly distributed particulate composites. Finally, the analytical results are compared with tensile test results to identify the model, which gives good correlations. Further, the experimental results and the theoretical calculations using the empirical models showed that the strength of the composites is closer to the strength of the weaker constituent matrix material, for all the composites tested and shows improvement over the unblended polyurethane based composites. Also improvement in the thermal properties is also evidenced from the test results.
Effects of Recycling Cycle on Used Thermoplastic Polymer and Thermoplastic Elastomer Polymer
Authors: Jiun Yu Lih , Tze Cher Tien , Moosa Usaid , Tawawneh Mou'ad A
Published: September 2018

Due to several environmental problems arising through the disposal of polymers, recycling has been growing rapidly as one of the best approaches to minimize environment pollution issue. Apart from the positive impacts towards environmental sustainability, recycling polymer is also benefiting in terms of manufacturing cost reduction, energy conservation and material resource conservation. The aim of this study was to investigate how recycling cycle affects the physical properties and mechanical properties for both used thermoplastic polymer and thermoplastic elastomer polymer. Samples were prepared by melting used polymers via melt blending technique. Results showed that tensile strength and density were decreased for thermoplastic polymer and the changes in visual are significant when the number of recycling cycle was increased. Tensile strength, yield strength and Young Modulus of thermoplastic elastomer are independent from number of recycling cycles. Presence of antioxidant fillers in thermoplastic elastomer enhanced the tensile strength (28.23%) and Young Modulus (29.16%) when the polymers were exposed to ultraviolet light.
TiO2-SiO2-Reinforced Methylated Grafted Natural Rubber (MG49-TiO2-SiO2) Polymer Nanocomposites: Preparation, Optimization and Characterization
Authors: Kang Oon Lee , Ahmad Azizan , Hassan Nur Hasyareeda , Rana Usman Ali , Suait Mohd Sukor , Migliaresi Claudio
Published: September 2018

TiO2-SiO2 (30:70) and (70:30) sol particles were first prepared through ClHNO2-EtOH catalysis; and then incorporated into methylated grafted natural rubber (MG49) polymer host. Resultant MG49-TiO2-SiO2 (30:70) and (70:30) polymer nanocomposites were characterized through XRD and FTIR analyses. Both MG49-TiO2-SiO2 (30:70) and (70:30) polymer nanocomposites had exhibited extensive reduction in semicrystalline phase; but no significant change in structural properties. Low crystalline MG49-TiO2-SiO2 (30:70) and (70:30) polymer nanocomposites were further characterized through SEM, TGA and DRA analyses. Both MG49-TiO2-SiO2 (30:70) and (70:30) polymer nanocomposites had exhibited different dispersion state on fracture surface. Both MG49-TiO2-SiO2 (30:70) and (70:30) polymer nanocomposites had demonstrated significant improvement in thermal properties, and also some improvement in rheological properties.
Polyethersulfone Nanofiltration Membrane Incorporated with Silicon Dioxide Prepared by Phase Inversion Method for Xylitol Purification
Authors: Faneer Khalefa A. , Rohani Rosiah , Mohammad A. Wahab
Published: September 2018

Xylitol purity is essential for a high value product obtained from biomass fermentation. Common biomass fermentation from sugar cane bagasse, corncobs or rice husk source in the presence of yeast produces xylitol mixture (containing xylose, arabinose), thus, various methods have been used for the purification such as crystallization and adsorption. However, membrane technique is of interest due to the operational simplicity and flexibility, relatively high selectivity and permeability for the transport of specific components. Nanofiltration (NF) membrane is targeted for the membrane application based on the ranges of molecular weight of the mixture components that fall in NF (between 200 to 2000 g/mol). In this paper, a new and efficient NF membrane used for purifying xylitol was synthesized from polyethersulfone (PES) and PES incorporated with silicon dioxide (SiO2) nanoparticles (NP) of 5 wt.% via phase inversion technique. These membranes have been characterized for their chemical, physical and morphological properties and their performances have been evaluated in the dead end filtration to obtain the pure water flux and filtration performance using xylitol mixture. EDX showed the presence of SiO2 NP on the membrane for PES/SiO2 membrane but none in PES membrane. The membrane permeation properties improved also when SiO2 has been incorporated to the PES membrane. The hydrophilicity of the PES/SiO2 membrane measured by contact angle improved from 79.7±0.65° to 59.1±0.15° for PES/SiO2 and PES membranes, respectively. The water flux has enhanced for PES/SiO2 membrane from 24.56 to 59.14 L/m2·h measured at 4 bar. Therefore, in terms of flux and contact angle, the synthesized membrane of PES/SiO2 was found to be more effective compared to pure PES membrane.
Managing uncertainty in creative industries: Film sequels and Hollywood’s profitability, 1988–2015
Authors: Pokorny Michael , Miskell Peter , Sedgwick John
Published: September 2018

The film industry is a creative industry in which novelty is an essential aspect. As a consequence, it is characterized by high levels of uncertainty for both producer and consumer. Yet the firms that dominate global film distribution have remained remarkably stable over the last century. The ability to transform uncertainty into risk, and to manage these risks effectively, has arguably been the outstanding achievement of major American film studios since the 1920s. This article examines how the risk management strategies of these firms have evolved over time, with a particular focus on the growing prevalence of sequels during the last 30 years. We analyse data on the box-office earnings and budgets of over 4000 films released between 1988 and 2015 and find that sequels have become an increasingly important source of industry profits since c.2000. We place this trend in historical context, and argue that while sequels themselves are not new, their role within film portfolios has changed, and that this represents a distinctive approach to risk management within the industry.
Ludic Markers for Player-Player Observation in Location-Based Mobile Games
Authors: Alavesa Paula , Pakanen Minna , Ojala Timo , Asare Kennedy Opoku , Ojala Karri , Lehto Mikko , Kukka Hannu
Published: September 2018

Background. It can be difficult to capture the subtleties of social behavior during gameplay by using existing commercial location-based mobile games as a research probe since they are not designed to reveal subtleties in player behavior. Aim. We sought to explore whether players spontaneously search for unknown fellow players and to identify ludic markers in player-player observation when playing a digital location-based mobile game that allows location spoofing in addition to automated locationing. Method. We used a constructive research approach and created a game specifically designed to allow location spoofing through self-reporting of player locations. We conducted three field trials with eight participants in total. They took part in separate field trials in groups of three, three, and two players. The participants were previously unknown to each other and commenced play at different locations inside the game area. Results and Conclusions. Qualitative analysis of the gathered video and interview material shows that the players spontaneously searched for unknown fellow players, which confirms earlier research on the topic. Further, behavioral and direct visual markers in the physical environment were reported to be the most significant cues in determining who is a player and who is not.
Incidence and Risk Factors of Symptomatic Venous Thromboembolism Following Foot and Ankle Surgery
Authors: Richey Johanna Marie , Ritterman Weintraub Miranda Lucia , Schuberth John M.
Published: September 2018

Background:

The incidence rate of venous thrombotic events (VTEs) following foot and ankle surgery is low. Currently, there is no consensus regarding postoperative prophylaxis or evidence to support risk stratification.

Methods:

A 2-part study assessing the incidence and factors for the development of VTE was conducted: (1) a retrospective observational cohort study of 22 486 adults to calculate the overall incidence following foot and/or ankle surgery from January 2008 to May 2011 and (2) a retrospective matched case-control study to identify risk factors for development of VTE postsurgery. One control per VTE case matched on age and sex was randomly selected from the remaining patients.

Results:

The overall incidence of VTE was 0.9%. Predictive risk factors in bivariate analyses included obesity, history of VTE, history of trauma, use of hormonal replacement or oral contraception therapy, anatomic location of surgery, procedure duration 60 minutes or more, general anesthesia, postoperative nonweightbearing immobilization greater than 2 weeks, and use of anticoagulation. When significant variables from bivariate analyses were placed into the multivariable regression model, 4 remained statistically significant: adjusted odds ratio (aOR) for obesity, 6.1; history of VTE, 15.7; use of hormone replacement therapy, 8.9; and postoperative nonweightbearing immobilization greater than 2 weeks, 9.0. The risk of VTE increased significantly with 3 or more risk factors ( P = .001).

Conclusion:

The overall low incidence of VTE following foot and ankle surgery does not support routine prophylaxis for all patients. Among patients with 3 or more risk factors, the use of chemoprophylaxis may be warranted.

Level of Evidence:

Level III, retrospective case series.
Lack of association between lysyl oxidase-like 1 polymorphism in pseudoexfoliation syndrome and pseudoexfoliation glaucoma in North Indian population
Authors: Pandav Surinder Singh , Chakma Partha , Khera Alka , Chugh Neera , Gupta Parul Chawla , Thattaruthody Faisal , Seth Natasha Gautam , Raj Srishti , Kaushik Sushmita , Khullar Madhu , Ram Jagat
Published: September 2018

Introduction:

Pseudoexfoliation syndrome is commonly associated with pseudoexfoliation glaucoma. The two nonsynonymous single-nucleotide polymorphisms rs1048661 (R141L) and rs3825942 (G153D) within exon 1 of LOXL1 gene have been found to confer risk of pseudoexfoliation syndrome and pseudoexfoliation glaucoma in different geographical populations. This study aims to find association between two nonsynonymous single-nucleotide polymorphisms with pseudoexfoliation syndrome and pseudoexfoliation glaucoma in North Indian population.

Methods:

North Indian subjects clinically diagnosed with pseudoexfoliation syndrome/pseudoexfoliation glaucoma and normal age-matched control were enrolled in the study. Genomic DNA was extracted and the two single-nucleotide polymorphisms of LOXL1 gene were genotyped by polymerase chain reaction and sequencing. The association between single-nucleotide polymorphisms with pseudoexfoliation syndrome/pseudoexfoliation glaucoma was evaluated by chi-square test.

Results:

A total of 30 pseudoexfoliation glaucoma, 27 pseudoexfoliation syndrome and 61 control subjects were enrolled in the study. Patients with pseudoexfoliation syndrome and pseudoexfoliation glaucoma did not show any genetic association with either single-nucleotide polymorphism rs1048661 or rs3825942.

Conclusion:

The study shows lack of association between LOXL1 single-nucleotide polymorphisms and pseudoexfoliation in North Indian population.
Consumer perceptions of using social media for health purposes: Benefits and drawbacks
Authors: Benetoli Arcelio , Chen Timothy F , Aslani Parisa
Published: September 2018

Consumers are increasingly using social media to interact with other consumers about health conditions and treatment options. This study aimed to investigate the advantages and disadvantages of using social media for health-related purposes from the consumers’ perspectives. Five focus groups with 36 Australian adults with a chronic condition and on medication were conducted, audio-recorded, transcribed verbatim, and thematically analysed. Consumers reported that social media was very convenient, for accessing health-related information and for peer engagement; user-friendly; improved their health knowledge; empowered them; and provided social and emotional support. The disadvantages included information overload, wasting time; negative feelings; doubts about online information credibility; and issues related to online interactions. Despite some disadvantages, health-related use of social media led consumers to feel supported, knowledgeable, and empowered. Consumers’ motivation to keep accessing social media for health-related purposes opens up avenues for the delivery of services via social media.
Lobbying cycles in Brussels: Evidence from the rotating presidency of the Council of the European Union
Authors: Hollman Michelle , Murdoch Zuzana
Published: September 2018

The Council presidency holds direct responsibility for the Council’s functioning and moves between EU member states via a six-month rotation scheme. We argue that this rotating Council presidency causes a lobbying cycle among interest groups at the European level, whereby national interest groups from the country holding the presidency temporarily become active at the European level. Using a unique dataset including almost 16,500 registrations of interest groups in the European Transparency Register over the 2008–2017 period, we confirm that holding the Council presidency increases the number of interest groups from that member state in the Transparency Register. We also find that national interest groups generally have a higher likelihood to exit the register following the end of their country’s presidency.
The Examination of the Structure Property Relationships of Some Water-Dispersed Polyurethane Elastomers
Authors: Heath Richard , Rungvichaniwat Adisai
Published: September 2018

Water-dispersed or latex polyurethanes (PUs) have been known for many years. However, in the last decade there has been an increased level of R&D interest into these types of polymers, with potential use as coating and adhesive materials. In part, this research has been driven by the introduction of laws and regulations intended to reduce and eliminate the use of organic solvents, and so to minimise environmental pollution. Latex or emulsion forms of PUs have been investigated because of their specific end-use properties, in particular excellent adhesion and long term barrier properties.

This paper reports a study of some experimental formulations of water-dispersed polyurethanes based on tetramethylxylene diisocyanate (TMXDI), some polyesterols or polyetherols polyols and an aliphatic diamine chain extender. These have been synthesised as water dispersions, with dimethylol prioponic acid and triethylamine used as providing anionic centres and neutralising agent, respectively in the aqueous phase.

Some properties of the various formulations as dispersions were determined, including particle size, surface free energy, viscosity and dispersion stability. Stable dispersions were subsequently converted into coherent, dry, thin sheet materials, which were characterised using thermal analysis and some mechanical test methods.

The research has shown it is possible to produce stable water-dispersed urethane-urea copolymers, based on different molar masses of polyesterol or polyetherol precursors and TMXDI, and also where hard segment content was varied (i.e. by different ratios of combined dialcohol species to diamine). It was found that stable dispersions can be made with a broad range of internal emulsifier content in the polymer chain, that have low viscosity and low surface free energy. Particle size of the polymer dispersions was affect by emulsifier content: higher levels producing small particles. At low levels of emulsifier, the stability of the dispersions was increasingly poor, while at higher levels, viscosity increased due to small particle size and increasing coulombic effects. Stable dispersions cast into thin dry films of coherent elastomers, have good mechanical properties, similar to those of urethane-urea copolymers synthesised by water-free methods. Thermal analysis suggests that the degree of phase mixing of hard and soft segment in these polymers, parallels that reported for to urethane-urea copolymers synthesised by water-free methods.
Recycling of Industrial Polyurethane Residue and the Characterisation of its Properties
Authors: Guedes Cristina das Graças Fassina , Rosa Derval dos Santos
Published: September 2018

The globalisation process has forced manufacturers to produce higher quality products with less environmental hazard. The newly developed industrial products produce residues, which pose challenges for recycling. In this work, we present the mechanical recycling of the industrial polyurethane residues incorporated in different proportions with polyurethane resins. Effect of temperature in the process and proportion of residues were considered for the process development. The products obtained in different proportions (weight of new resin: weight of residue) 1:4, 1:8, 1:12.5, 1:20 have been characterised by mechanical properties, resistance to abrasion and hardness which are required for the possible applications of the developed product.
Studies on Thermo-Mechanical Properties of Post-Consumer High Impact Polystyrene in Five Reprocessing Steps
Authors: Santana R.C. , Manrich Sati
Published: September 2018

This study consisted of an investigation of the thermo-mechanical properties of post-consumer high impact polystyrene (HIPS) through five consecutive injection moulding steps to simulating the recycling cycles. The selectively collected HIPS residue was ground, washed only in water, dried, agglutinated and then moulded as a set of mechanical test specimens before the first step. The melt flow index (MFI), glass transition temperature (Tg), complex viscosity (η*), deflection temperature under flexural load (HDT), tensile, flexural and impact strength tests were determined at each reprocessing cycles. The results revealed that the degradative effect of consecutive recycling on the material's thermal properties was low and may be considered negligible. After five reprocessing cycles, the results showed an ∼8°C decrease of Tg in DSC, an increase of MFI, a decrease in viscosity and a slight decrease of HDT, which could be attributed to chain scission caused by consecutive cycles of exposure to shear stresses and high temperature. The material became slightly more rigid and fragile, as indicated by the mechanical tests.
A Review on Heat and Reversion Resistance Compounding
Authors: Datta R. N.
Published: September 2018

When sulfur vulcanized natural rubber compounds are exposed to a thermal ageing environment significant change in physical properties and performance characteristics are observed. These changes are directly related to modifications of the original crosslink structure. Decomposition reactions tend to predominate and thus leading to reduction in crosslink density and physical properties as observed during extended cure and when using higher curing temperatures. The decrease in network density is common when vulcanizates are subject to an anaerobic ageing process. However, in the presence of oxygen, the network density is increased with the main chain modifications playing a vital role.

Over the years the rubber industry has developed several compounding approaches to address the changes in crosslink structure during thermal ageing. This paper gives a review of these compounding approaches. As with many formulation changes in rubber compounding, there is a compromise that must be made when attempting to improve one performance characteristic. For example, improving the thermal stability of vulcanized natural rubber compounds by reducing the sulfur content of the crosslink through the use of the more efficient vulcanization systems will reduce dynamic performance property such as fatigue resistance. The challenge is to define a way to improve thermal stability while maintaining dynamic performance characteristics.
Recyclable Nylon Reinforced HDPE Composites: Effect of the Fibre Diameter
Authors: Abraham Thomas N. , George K.E.
Published: September 2018

A commercial grade of high-density polyethylene (HDPE) reinforced with nylon 6 fibres of three diameters at levels up to 30 wt% HDPE. The addition of the fibres resulted in improvements in mechanical properties such as tensile strength and flexural strength. Fibres having the least diameter gave the maximum improvement in mechanical properties. Attempts were made to improve the interfacial adhesion between the fibres and the matrix by grafting the matrix with maleic anhydride and also with styrene maleic anhydride. The mechanical properties showed significant improvements as a result of these modifications. The HDPE/nylon composites/blends obtained by recycling the composites also show good mechanical properties.
An Investigation on the EPDM Devulcanization in Co-rotating Twin Screw Extruder by Response Surface Methodology
Authors: Jalilvand A.R. , Ghasemi I. , Karrabi M. , Azizi H.
Published: September 2018

In this study the effects of barrel temperature, screw speed and the devulcanization agent content on ethylene-propylene-diene-monomer (EPDM) devulcanization were investigated using co-rotating twin screw extruder. A Box-Behnken design for three variables, at three levels, was chosen as an experimental design. Sol fraction and Mooney viscosity of devulcanized rubber and mechanical properties of revulcanizates were considered as the responses. Response Surface Methodology (RSM) was used for analyzing the result of the experiments. The results indicated that the sol fraction increased with increasing the barrel temperature and screw speed but the barrel temperature was more effective than screw speed upon devulcanization of EPDM. Mooney viscosity decreased with the increase of barrel temperature. Tensile strength of revulcanized rubber showed a maximum value with the rise of devulcanization temperature, while the elongation at break increased with the increase of the barrel temperature, screw speed and devulcanization agent content. The accuracy of the models was confirmed by the experimental data.
An Overview of Rubber Recycling
Authors: Bandyopadhyay S. , Agrawal S.L. , Ameta R. , Dasgupta S. , Mukhopadhyay R. , Deuri A.S. , Ameta Suresh C. , Ameta Rakshit
Published: September 2018

Since the discovery of vulcanisation, rubber has become an indispensable material for the technological development of civilisation, starting from a simple balloon to complex rocket propellant. Rubber Industry worldwide is using on an average 50% of raw materials. These materials are mostly petroleum-based, except natural rubber (NR), steel cord and bead wire. Use of these petroleum-based raw materials not only depletes natural resources, but also produces more extreme environmental hazards. Escalation of petroleum prices, greater awareness of the environment has resulted in different recycling and environmental friendly technologies. Furthermore, the new concept of ‘Cradle to Grave’ has created a significant concern to the manufacturer about present use of petroleum-based raw materials in the rubber industry worldwide. For both environmental and economic reasons, there is also a continuing broad-based interest in the recycling of scrap rubber and rubber recycled materials and therefore in the development of recycling technologies.
Effect of Carbon Black on the Mechanical and Dielectric Properties of Rubber Ferrite Composites
Authors: Prema K.H. , Kurian Philip , Sanoj M.A. , Anantharaman M.R.
Published: September 2018

Nanoparticles of nickel ferrite are synthesised by sol-gel technique. They are then characterised by X-ray diffraction technique (XRD) and Vibrating sample magnetometer (VSM). Precharacterised ultra fine nickel ferrite is then incorporated in ethylene propylene diene rubber (EPDM) according to a specific recipe. The prepared rubber ferrite composites (RFCs) are found to have appreciable mechanical and dielectric properties. Addition of appropriate amount of carbon black to RFCs substantially improves its dielectric properties. Variation of dielectric properties of RFCs with frequency is studied in the frequency range 0.1-8 MHz and is found to vary in accordance with MaxwellWagner interfacial polarisation. dc conductivity of the RFCs is also measured and correlated with filler loading.
Ground Tyre Rubber/Waste Polypropylene Blends – Effect of Composition on Mechanical Properties
Authors: Egodage Shantha Maduwage , Harper John F. , Walpalage Shantha
Published: September 2018

Ground tyre rubber (GTR) was blended with waste polypropylene (WPP) in nine different compositions to prepare GTR/WPP blends. The blends were prepared in a Haake Rheocord PolyLab system at a temperature of 180 °C and a rotor speed of 30 r/min for 8 min. The processing characteristics of the blends showed an increase in steady-state mixing torque with an increase in GTR content, suggesting an increased difficulty in processability at GTR loadings above 30 wt.%. Morphological observations of the blends showed two-phase systems. The GTR was dispersed in a continuous WPP matrix in blends containing up to 60 wt.% GTR, and the size of the dispersed GTR agglomerants increased with GTR content. At 70 wt.%, the GTR dispersed phase changed to a continuous phase. Tensile strength, modulus, and tear resistance decreased with GTR content, while the elongation at break and the impact failure energy increased. All these properties remained relatively unchanged at low GTR contents, suggesting that a critical GTR level is required to obtain rubber-like properties in a simple rubber–thermoplastic blend.
Characterization of Polyurethanes Containing Different Chain Extenders
Authors: Orgilés-Calpena Elena , Arán-Aís Francisca , Torró-Palau Ana M. , Orgilés-Barceló César
Published: September 2018

Several waterborne polyurethane adhesives containing different chain extenders were prepared by using the acetone process. Concretely, the polyurethane dispersions were synthesized by the prepolymer method based on three chain extenders: two diols and one diamine: 1,4-butanediol, 1,6-hexanediol and hydrazine.

The adhesive solutions were characterized by flow rheology, pH measurements, particle size and solids content. The solid adhesive films were characterized by plate-plate rheology, dynamic mechanical analysis (DMA) and differential scanning calorimetry (DSC). The adhesion properties were measured from T-peel test of leather/polyurethane adhesive/SBR rubber joints.

As a result, the chosen chain extender influences significantly the polyurethane synthesized properties, specially determines the crystallinity of the polymer, as well as thermal and adhesive properties. Particularly, the molecular weight of the chain extender determines the structure of the synthesized polyurethanes.
A Novel Reclaiming Agent for Ground Rubber Tyre (GRT). Part II: Property Evaluation of Virgin Natural Rubber (NR)/Novel Reclaimed GRT Revulcanisates
Authors: Edirisinghe D.G. , De Silva M.I.A. , Premachandra J.K.
Published: September 2018

Blending of recycled scrap rubber such as reclaimed rubber with virgin rubber has increased over the last few years, especially in the manufacture of tyre components. The reason for this is the growing concern about the effect of rubber product waste on the environment and the rise in the costs of virgin rubbers. In this study, physicomechanical properties such as tensile properties, tear strength, hardness, resilience, abrasion resistance, ageing performance, and swelling behaviour as well as carbon black dispersion rating of 85/15 virgin NR/novel reclaimed ground rubber tyre (GRT) revulcanisates were evaluated and compared with those of control vulcanisates. Results revealed that the abrasion volume loss of blends of virgin NR and novel reclaimed rubber revulcanisates is lower than that of revulcanisate prepared with a blend of 85/15 virgin NR/reclaimed rubber (Control (Rec)), produced locally, and comparable with that of 100% NR vulcanisate (Control (NR)). Although the tensile strength and elongation at break of the virgin NR/novel reclaimed rubber revulcanisates are lower than those of the Control (NR) vulcanisate, these values are at a level acceptable for tyre treads. Hence, the 85/15 virgin NR/novel reclaimed rubber revulcanisates prepared with the readily available, low-cost, environmentally friendly amino compound can be used as an alternative to the Control (NR) and Control (Rec) vulcanisates in tyre treads.
Discretionary Surgery: A Comparison of Workers’ Compensation and Commercial Insurance
Authors: van der Gronde Bonheur A. T. D. , Crijns Tom J. , Ring David , Leung Nina
Published: September 2018

Background: Workers’ compensation is intended for injuries that occur at work and is expected to be mostly for trauma and mostly nondiscretionary conditions. We tested the null hypothesis that there is no difference in the ratio of likely discretionary to likely nondiscretionary surgery between patients treated under workers’ compensation compared with commercial insurance controlling for age, sex, and anatomical site for either traumatic or nontraumatic diagnoses. Methods: Using claims data from the Texas workers’ compensation database and Truven Health commercial claims we classified International Statistical Classification of Diseases and Related Health Problems, Ninth Revision, Clinical Modification (ICD-9-CM) diagnoses and procedure codes as likely discretionary or likely nondiscretionary, and as traumatic or nontraumatic. Ratios of likely discretionary to likely nondiscretionary surgery were calculated and compared. Results: Among patients treated under workers’ compensation, the ratio of likely discretionary to likely nondiscretionary surgery was significantly higher for traumatic diagnoses (0.57 [95% confidence interval, CI, = 0.56-0.61] vs 0.38 [95% CI = 0.37-0.40], P < .05) and significantly lower for nontraumatic diagnoses (9.4 [95% CI = 9.20-9.42] vs 13.2 [95% CI = 12.9-13.3], P < .05) compared with commercial insurance. Conclusions: Workers’ compensation often covers likely discretionary musculoskeletal surgery, and insurance type may influence treatment.