Crosslinking of fibers via azide–alkyne click chemistry: Synthesis and characterization

There has been growing interest in fiber modification for several industrial applications. The modifications have mostly been done to improve the fiber properties. However, the information regarding fiber modification via click chemistry is still limited. In this work, two strategies of click chemistry are evaluated for modifying commercial paper without the addition of copper catalyst. The first strategy is the direct reaction between azidated fiber and propargylated fiber, and the second strategy is to bridge azidated fiber with a self‐made alkyne terminal crosslinker. Native and chemically modified fibers were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, and ¹H‐NMR spectroscopy. The effects of the two clicking strategies on the fiber were further investigated by making handsheets. In terms of mechanical properties, the bridge‐clicking strategy was found to produce better handsheets than the direct‐clicking strategy. These modified fibers would be an interesting application for the packaging and printing industries. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43576.     

Solar photovoltaic in Malaysia: The way forward

This paper examines solar photovoltaic (PV) in Malaysia. First, it analyzes the current energy demand in Malaysia and discusses some of the national policies and the installations of solar PV in urban and rural areas in the country. Next, the general Feed-In Tariff (FiT) scheme is explained, indicating its potential as one of the investment options for Malaysians. Finally, the loan financing option for solar PV is presented, providing examples that have been implemented in other countries, as well as explaining the Green Technology Financing Scheme (GTFS) for companies and the proposed soft loan scheme for individual households in Malaysia. It also analyses the impact of the proposed interest rate to household consumers in Malaysia, in terms of total profit, net present value and internal rate of return. It is found that the FiT scheme could potentially help in increasing renewable energy penetration, particularly for solar PV. To provide upfront capital for solar PV installation, it is shown that the GTFS is a good financial source for companies while for individual home owners, a soft loan facility from banking institutions is a feasible source if the interest rate is 5% or less.     

17% Efficient Organic Solar Cells Based on Liquid Exfoliated WS2 as a Replacement for PEDOT:PSS

The application of liquid‐exfoliated 2D transition metal disulfides (TMDs) as the hole transport layers (HTLs) in nonfullerene‐based organic solar cells is reported. It is shown that solution processing of few‐layer WS₂ or MoS₂ suspensions directly onto transparent indium tin oxide (ITO) electrodes changes their work function without the need for any further treatment. HTLs comprising WS₂ are found to exhibit higher uniformity on ITO than those of MoS₂ and consistently yield solar cells with superior power conversion efficiency (PCE), improved fill factor (FF), enhanced short‐circuit current (J_SC), and lower series resistance than devices based on poly(3,4‐ethylenedioxythiophene):poly(styrenesulfonate) and MoS₂. Cells based on the ternary bulk‐heterojunction PBDB‐T‐2F:Y6:PC₇₁BM with WS₂ as the HTL exhibit the highest PCE of 17%, with an FF of 78%, open‐circuit voltage of 0.84 V, and a J_SC of 26 mA cm^?2. Analysis of the cells' optical and carrier recombination characteristics indicates that the enhanced performance is most likely attributed to a combination of favorable photonic structure and reduced bimolecular recombination losses in WS₂‐based cells. The achieved PCE is the highest reported to date for organic solar cells comprised of 2D charge transport interlayers and highlights the potential of TMDs as inexpensive HTLs for high‐efficiency organic photovoltaics.     

Meshing interfaces of multi-label data with Delaunay refinement

In medical imaging, the generation of surface representations of anatomical objects obtained by labeling images from various modalities, is a critical component for visualization, simulation, and analysis. The interfaces between labeled regions can meet at arbitrary angles and with complex topologies, causing most automatic meshing algorithms to fail. We apply a recent Delaunay refinement algorithm to generate high quality triangular meshes that approximate the interface surfaces. This algorithm has proven guarantees for meshing piecewise-smooth shapes and its implementation overhead is low. Consequently, the approach is applicable to labeled datasets generated from binary segmentations as well as from probabilistic segmentation algorithms. We show the effectiveness of this technique on data from a variety of medical fields and discuss its ability to control the quality and size of the output meshes. The same algorithm can be used to generate tetrahedral meshes of the segmentation space.     

New General Principle of Mechanics and Its Application to General Nonideal Nonholonomic Systems

In this paper we develop a general minimum principle of analytical dynamics that is applicable to nonideal constraints. The new principle encompasses Gauss’s Principle of Least Constraint. We use this principle to obtain the general, explicit, equations of motion for holonomically and/or nonholonomically constrained systems with non-ideal constraints. Examples of a nonholonomically constrained system where the constraints are nonideal, and of a system with sliding friction, are presented.     

An evaluation of the installation of solar photovoltaic in residential houses in Malaysia: Past,present, and future

This paper examines solar energy development in Malaysia, particularly in relation to the installation of solar Photovoltaic (PV) in residential houses. It analyzes the past activities related to solar energy in Malaysia, in terms of research and developments (R&Ds), the implementations used as well as the national policies for the past 20 years which have pushed the installation of PV in the country. The Feed-In Tariff (FiT) scheme is discussed, showing comparative cost-benefit analysis between the PV installation in houses in the United Kingdom (UK) and Malaysia, and with other investment schemes available in Malaysia. To investigate the awareness of renewable energy policies and incentives, a preliminary survey of the public opinion in Malaysia has been carried out, and an evaluation of public willingness to invest in the FiT scheme by installing the PV on their houses is presented. The cost-benefit analysis shows that the proposed FiT programme is capable of generating good return on investment as compared to the one in the UK, but the return is lower than other investment tools. The survey suggests that most Malaysians are unaware of the government’s incentives and policies towards renewable energies, and are not willing to invest in the FiT scheme.     

The Effect of Storage Time and Humidity on Mechanical and Physical Properties of Medium Density Fiberboard (MDF) from Oil Palm Empty Fruit Bunch and Rubberwood

Commercial medium density fiberboard (MDF) was produced using rubberwood and oil palm empty fruit bunch (OPEFB) based on oven dried weight. Relative humidities of 65%, 93% with fixed temperature at 20°C, and normal condition was used for storage of the boards. The effects of storage time and relative humidity of MDF were assessed by measuring the changes of the board mechanical and physical properties for 10 weeks at 2 week intervals. The mechanical tests involved were internal bonding and flexural test, whereas physical tests were moisture content, thickness swelling, water absorption, and scanning electron microscope. The result showed that at 65% humidity, MDF exhibited a lower effect on the mechanical and physical properties of the panel, whereas at 93% humidity, the panel exhibited a decrease in the dimensional stability and mechanical properties of the board. Possible mechanisms behind this reduction are discussed.     

Viscosity,shear strength,and peel strength on poly(ethylene terephthalate) of (natural rubber)‐based adhesives containing hybrid tackifiers

The viscosity, shear strength, and peel strength of [natural rubber (Standard Malaysian Rubber (SMR) L grade)]‐based pressure‐sensitive adhesives were studied by using hybrid tackifiers, i.e., mixtures of coumarone–indene resin and petro resin. Toluene and poly(ethylene terephthalate) were used as the solvent and substrate, respectively. Viscosity of the adhesives was determined with a HAAKE rotary viscometer, whereas shear and peel strength were measured by a Lloyd adhesion tester. Results showed that the viscosity and shear strength decreased with increasing petro resin concentration, an observation which is attributed to the plasticizing effect of the resin. Peel strength, however, showed a maximum value at 60 phr (parts by weight per hundred parts of resin) petro resin concentration, thus indicating maximum wettability at this petro resin content. Peel strength increased with coating thickness for all the peel tests studied. In all cases, a 90° peel test consistently exhibited the highest peel value. J. VINYL ADDIT. TECHNOL., 2011. © 2011 Society of Plastics Engineers