Motorcyclist's Riding Discomfort in Malaysia: Comparison of BMI,Riding Experience,Riding Duration and Riding Posture

There is very little (or no) information about the riding discomfort of motorcyclists in Malaysia. Therefore, this study was done with the intention of highlighting the relationship of the discomfort on the motorcyclist's body parts during the riding process concerning factors such as body mass index (BMI), riding experience, riding hours, and preferred riding posture. This study (questionnaire survey) was done by using 957 respondents (481 males and 476 females) with an age range from 18 years to 24 years, which was collected from a previous study. The results indicate that the majority of motorcyclists who participated in this study are in the normal BMI category. However, the majority of these motorcyclists suffer discomfort in their body parts during the riding process. It is noticeable that the majority of female motorcyclists started with higher discomfort symptoms concerning the corresponding factors (BMI, riding hours, and riding experience) compared with male motorcyclists. Most male discomfort symptoms were focused on the buttock and upper body parts, whereas the female motorcyclists experienced discomfort in all of their body parts (lower, buttocks, and upper body parts). Furthermore, the results also highlight that the motorcyclists' discomfort was correlated with riding posture. Therefore, this study clearly identified that motorcyclists experience discomfort in their body parts during the riding process. The findings also highlight that the current interaction of humans (motorcyclists) and machine (motorcycle) is not an ideal ergonomic philosophy. However, further detailed study (laboratory and field study) needs to be done to uncover fully the parameters or factors that constrain the ergonomic comfortability in the motorcycle riding process. © 2011 Wiley Periodicals, Inc.     

The effect of protein adsorption on the friction behavior of ultra-high molecular weight polyethylene

Medical-grade UHMWPE samples with two different surface finishing treatments, milling and melting/reforming were exposed to 10% bovine serum albumin solution and their friction responses were quantified using atomic force microscopy. The observed friction increase upon exposure to proteins was attributed to the formation of a layer of denatured proteins on the surface. Changing the crystallinity and surface energy of UHMWPE affected the protein adsorption mechanism and the resulting increase in friction behavior.     

The role of the sea-surface microlayer in the air-sea gas exchange of organochlorine compounds

Simultaneous measurements of organochlorine compounds (OCs) in seawater, the sea-surface microlayer and the atmosphere were conducted in June-July 2004 in the coastal marine environment of Singapore. Together, these measurements represent the first data on the flux of OCs between the ocean and atmosphere reported in the scientific literature that take into account the implication of the sea surface microlayer (SML) as a controlling boundary layer for the exchange of OCs. The average fluxes of SigmaPCBs and SigmaHCHs were 127.5 and -32.8 ng m(-2) day(-1) respectively using a modified two-layer model (negative flux indicates adsorption by the ocean). The average fluxes using a conventional approach, ignoring the SML as boundary layer (classical two-layer model), were 67.2 and -43.1 ng m(-2) day(-1) for SigmaPCBs and SigmaHCHs, respectively. However, the maximum difference in the flux calculation between the two approaches was up to 15-fold for individual compounds at high enrichment in the SML. It is shown that the SML plays an important role in the control of air-sea gas exchange of OCs, particular under a low prevailing wind regime and with an enrichment of OCs in the SML. The physical and chemical properties of OCs are critical factors in the control of the air-sea gas exchange process, and the effect of the SML on this process is more significant for more hydrophobic OCs.     

Multiobjective optimization under uncertainty of the economic and life‐cycle environmental performance of industrial processes

The combined use of multiobjective optimization and life‐cycle assessment (LCA) has recently emerged as a useful tool for minimizing the environmental impact of industrial processes. The main limitation of this approach is that it requires large amounts of data that are typically affected by several uncertainty sources. We propose herein a systematic framework to handle these uncertainties that takes advantage of recent advances made in modeling of uncertain LCA data and in optimization under uncertainty. Our strategy is based on a stochastic, multiobjective, and multiscenario mixed‐integer nonlinear programming approach in which the uncertain parameters are described via scenarios. We investigate the use of two stochastic metrics: (1) the environmental impact in the worst case and (2) the environmental downside risk. We demonstrate the capabilities of our approach through its application to a generic complex industrial network in which we consider the uncertainty of some key life‐cycle inventory parameters. © 2014 American Institute of Chemical Engineers AIChE J, 60: 2098–2121, 2014     

Development of perfluorosulfonic acid polymer-based hybrid composite membrane with alkoxysilane functionalized polymer for vanadium redox flow battery

A new kind of alkoxy silane functionalized polymer (ASFP) is synthesized by selectively functionalized carboxyl groups as a novel inorganic precursor polymer to prepare organic-inorganic hybrid membrane for vanadium redox flow battery (VRFB) system. The novel hybrid membrane has been fabricated by interconnection between hydrophilic domains of Nafion and ASFP functional group. The effective concentration of ASFP for hybrid membrane is 25% (wt/wt). The proton conductivity and selectivity of the hybrid membrane are comparable with those of the Nafion212 membrane, which is mainly attributed by the presence of additional hydrophilic domains in the hybrid membrane. The proton conductivity and ion exchange capacity of the Nafion-ASFP (75:25) membrane is 0.061 S/cm and 0.68 meq/g, respectively. Remarkably, the Nafion-ASFP membrane shows a low vanadium permeability (1.259 × 10⁻⁷ cm²/min) and high selectivity, which is an excellent advantage. As a result, the hybrid membrane shows comparable efficiency performance with Nafion212 over 50 cycles. Notably, the VRFB unit cell with Nafion-ASFP membrane achieves higher coulombic efficiency than Nafion212. The hybrid membrane reveals a new route to develop an alternative fluorinated polymer membrane with numerous advantages especially cost-effectiveness, homogeneous dispersion of inorganic silica precursor materials in the hybrid membrane without deterioration of mechanical strength, and lower vanadium ion crossover for VRFB system.     

Cobalt-doped layered lithium nickel oxide as a three-in-one electrode for lithium-ion and sodium-ion batteries and supercapacitor applications

Layered LiNi_0.94Co_0.06O₂ (LNCO) was prepared and explored as an energy-storage material for Li-ion (LIBs), Na-ion (SIBs) batteries as well as supercapacitor application for the first time. All the physical and morphological characterizations were studied for the sample LNCO. The result displays good thermal stability, phase purity in the crystal structure, appreciable Brunauer-Emmett-Teller (BET) surface area (5.53 m² g⁻¹) and possesses cubic morphology. The cobalt was identified in lithium nickel oxide with binding energies at 794.02, 779.04 and 784.30 eV, respectively. In the case of LIBs, LNCO exists with a minimal difference of 5 mAh g⁻¹, even when cycled from 2C to 0.1C. After 200 cycles, the specific capacity, 247 mAh g⁻¹, is obtained for the cell with retention of 97.8% (efficiency 99.8%) at 0.1C. In SIBs, at 0.1C, the discharge capacity of 182 mAh g⁻¹ was restored even when cycled after 2C. After 200 cycles, a discharge capacity of 204 mAh g⁻¹ is ensured with retention of 96.6% (efficiency of 99.4% at 0.1C). In supercapacitor, the electrode, LNCO, delivered a specific capacity of 300 F g⁻¹ at 0.5 A g⁻¹. Therefore, LNCO is highly recommended as a suitable electrode material for fulfilling the requirement of energy-storage applications.     

CMP工艺流程控制策略

化学机械抛光工艺控制和测量技术随着其工艺重要性的日益提高越来越成熟。测量技术在所有类型的化学机械抛光工艺流程控制中扮演了一个重要的角色,并且可以根据使用的测量技术、其在工艺流程中所处的位置以及类型和产生的数据量以不同的方法实现。述评并提出了一些从现场、延伸的现场、综合的测量技术、以及其对工艺流程控制的影响和普遍应用的测量技术的例子。并且还提出了65nm以及更小技术节点的测量技术以及工艺流程控制策略,在这些未来的技术中,晶片工艺控制以及每个晶圆片方法调整预计将更加苛刻。     

Evaluation of Friction Behavior and Its Contact-Area Dependence at the Micro- and Nano-Scales

The friction behavior of two different materials, mica and ultra-high molecular weight polyethylene (UHMWPE), was evaluated at the nanoscale with an atomic force microscope and with a custom-built ball-on-flat microtribometer at the microscale. The same counterface (Si₃N₄ probe), environmental conditions (25 °C, RH < 10%), and similar load ranges were maintained for all experiments. The friction-force data obtained were analyzed for contact-area dependence. Friction force between silicon nitride and mica at the nanoscale showed initial non-linearity with normal load up to a certain load, beyond which surface damage was observed resulting in a linear dependence of friction force on normal load. At the microscale, the friction force of the mica–silicon nitride interface exhibited linear dependence on normal load. Friction force between silicon nitride and UHMWPE exhibited non-linearity with normal load at both the length scales, for the applied load ranges of our experiment. An appropriate contact mechanics theory was applied to calculate an interfacial shear strength value for the material pair at both the scales. The values at both the scales were similar, when the conditions were carefully maintained to be the same across scales.     

Design and application of stimulus-responsive peptide systems

The ability of peptides and proteins to change conformations in response to external stimuli such as temperature, pH and the presence of specific small molecules is ubiquitous in nature. Exploiting this phenomenon, numerous natural and designed peptides have been used to engineer stimulus-responsive systems with potential applications in important research areas such as biomaterials, nanodevices, biosensors, bioseparations, tissue engineering and drug delivery. This review describes prominent examples of both natural and designed synthetic stimulus-responsive peptide systems. While the future looks bright for stimulus-responsive systems based on natural and rationally engineered peptides, it is expected that the range of stimulants used to manipulate such systems will be significantly broadened through the use of combinatorial protein engineering approaches such as directed evolution. These new proteins and peptides will continue to be employed in exciting and high-impact research areas including bionanotechnology and synthetic biology.     

Effect of dehydration rate on non-hydrolytic TiO2 thin film processing: Structure,optical and photocatalytic performance studies

The influence of complexing agent diethanolamine (DEA) on the rate of dehydration due to hydrolysis in titania thin films prepared by non-aqua sol–gel process was investigated. The formation of complex with titanium precursor controls the rate of hydrolysis over wide range of temperature. The rate of hydrolysis with respect to complex formation and firing temperate was studied by using thermogravimetry and differential thermal analysis (TG–DTA). The role of complexing agent in the crystallization of anatase and phase transformation to rutile was studied by X-ray diffraction (XRD). Effect of complexing agent on the optical transmittance in the visible range was monitored by ultraviolet–visible absorption spectroscopy. Photocatalytic performance of the titania films was measured using methylene blue (MB) as the model contaminant. Mechanical characteristics such as hardness and adhesion of the film were rated by using scratch tests as per ASTM standards.