Physico-mechanical and degradation properties of biodegradable photografted coir fiber with acrylic monomers

Coir fibers were modified with 2-hydroxyethyl methacrylate (HEMA), methyl methacrylate (MMA) and 2-hydroxyethyl acrylate (2-HEA) solutions under UV radiation. Monomer concentration and radiation dose were optimized in terms of grafting and tensile properties. It was found that 20 % HEMA at 20th UV pass, 30 % MMA at 15th UV pass and 25 % 2-HEA at 20th UV pass of radiation produced higher tensile properties over untreated sample. Urea of different concentrations (0.5–2 %) were incorporated into optimized solutions and 1 % urea showed the best properties of the fiber. Water uptake behavior and simulating weathering degradation properties were also performed.     

Design and Performance of a Laboratory Spray Dryer to Realize Evaporation-Induced Self-Assembly of Nanoparticles

This work discusses the design, development, and performance of an indigenous laboratory spray dryer with a relatively slow drying rate. The drying time of droplets of colloidal silica (5 wt%) and sodium chloride solution (20 wt%) in this spray dryer was nearly 10 s. The present system was composed of a four-jet compressed air nebulizer that generates a droplet size of 2–5 µm with a nebulization rate of nearly 60 mL/h. The generated powder can be collected using a cyclone or a wire mesh collector. Design and characterization of this system as well as characterization of the micrometric self-assembled powder grains obtained by this spray dryer are discussed.     

Heat Pump Drying of Green Sweet Pepper

Thin-layer drying experiments under controlled conditions were conducted for green sweet pepper in heat pump dryer at 30, 35, and 40°C and hot air dryer at 45°C with relative humidities ranging from 19 to 55%. The moisture content of sweet pepper slices reduced exponentially with drying time. As the temperature increased, the drying curve exhibited a steeper slope, thus exhibiting an increase in drying rate. Drying of green sweet pepper took place mainly under the falling-rate period. The Page equation was found to be better than the Lewis equation to describe the thin-layer drying of green sweet pepper with higher coefficient of determination and lower root mean square error. Drying in heat pump dryer at 40°C took less time with higher drying rate and specific moisture extraction rate as compared to hot air drying at 45°C due to lower relative humidity of the drying air in a heat pump dryer though the drying air temperature was less. The retention of total chlorophyll content and ascorbic acid content was observed to be more in heat pump–dried samples with higher rehydration ratios and sensory scores. The quality parameters showed a declining trend with increase in drying air temperature from 30 to 45°C. Keeping in view the energy consumption and quality attributes of dehydrated products, it is proposed to dry green sweet pepper at 35°C in heat pump dryer.     

Polysaccharide Biomaterials

An entire new genus of “polymer therapeutics” has emerged with wide applicability, including as mechanical supports, mechanical barriers, artificial tissue/organs, and pro-drug preparations with pharmacological effects. Polysaccharides are a class of biopolymers formed from many monosaccharide units joined together by glycosidic linkages. The physical properties of carbohydrates, such as solubility, gelation, and surface properties, are dictated by the monosaccharide composition, chain shapes, and molecular weight. These macromolecules exhibit good hemocompatibility, are non-toxic, and show unique biological functions, ranging from cell signaling to immune recognition. With few exceptions, they are more economical in comparison with others biopolymers. Polysaccharide-based polymers have been widely proposed as scaffold materials in tissue engineering applications as well as carriers for drug delivery.     

Anticandidal activity of cobalt containing sunflower oil‐based polymer

Bioactive metal cobalt containing sunflower oil‐based polyesteramide resin was developed by condensation polymerization reaction among oil‐derived sunflower fatty amide diol, adipic acid, and cobalt chloride. Microwave‐assisted synthesis was used throughout the reaction as it enhances reaction rate, gives higher yield, and greater purity of the products. Spectroscopic techniques, such as Fourier transform infrared spectroscopy and proton‐nuclear magnetic resonance, have been used to establish the structure of the polymers. Presence of cobalt in polymer has been confirmed through atomic absorption spectroscopy. Standard laboratory methods such as acid value, hydroxyl value, saponification value, iodine value, specific gravity, and viscosity were used to study the physicochemical characteristics of the polymers. Thermal behavior of the polymer was analyzed using thermogravimetry/differential thermal analysis. The synthesized polymers were evaluated for their biological activity. This study indicates that the synthesized polymer has significant antifungal activity against Candida, including azole‐resistant strains, advocating further investigation for clinical applications in the treatment of fungal infections. POLYM. ENG. SCI., 53:2650–2658, 2013. © 2013 Society of Plastics Engineers     

Preparation,characterization, and properties of polyacrylonitrile–silica gel anion exchange composite fibers

This article reports the preparation of new anion exchange composite fibers (AECFs). These AECFs were prepared by simple stirring of polyacrylonitrile (PAN) and silica gel in different stoichiometric ratios. The physicochemical characterization of the prepared AECFs was characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, X‐ray diffraction analysis, thermogravimetric analysis (TGA, differential thermal analysis, and differential thermal gravimetry), and elemental analysis (CHNS/O). Ion‐exchange behavior was also observed. The results indicate that addition of silica gel affects the structure and properties of the composite fibers. The addition of silica gel also changes the thermal stability of PAN–silica gel AECFs. The ion‐exchange capacity of the resulting AECFs was found to be 1.98 mequiv/g. POLYM. ENG. SCI., 2013. © 2013 Society of Plastics Engineers     

A Knowledge Based Design Methodology for manufacturing assembly lines

In assembly line design, the problem of balancing has received most attention from past researchers, and a number of algorithms have been devised for the analysis of single, multi- and mixed-product assembly lines [Int. J. Prod. Res. 27 (1989) 637]. In many cases, such algorithms seek a solution for the particular situation, which is under consideration and therefore have very little flexibility for generic application to assembly line design. Real life practical design issues include stochastic operation times, parallel workstation requirements, feasibility for workstation combining, and parallel line implementations, all of which are features which are ignored in many analyses. This paper presents a Knowledge Based Design Methodology (KBDM) for automated and manual assembly lines, which can be applied equally well to single, multi- and mixed-product assembly lines with either deterministic operation times or stochastic operation times. The methodology starts from a suitable assembly system selection and thereafter decides suitable cycle times, parallel workstation requirements, and parallel line implementation for the type of assembly system being selected. An economical number of workstations are decided with the aid of workstation combining options depending upon the factual information provided. The end result is the detailed design of a manufacturing assembly line. A case study from a practical assembly line is presented to illustrate how the KBDM works.     

Collision Free Mobility Adaptive (CFMA) MAC for wireless sensor networks

In this paper we propose high throughput collision free, mobility adaptive and energy efficient medium access protocol (MAC) called Collision Free Mobility Adaptive (CFMA) for wireless sensor networks. CFMA ensures that transmissions incur no collisions, and allows nodes to undergo sleep mode whenever they are not transmitting or receiving. It uses delay allocation scheme based on traffic priority at each node and avoids allocating same backoff delay for more than one node unless they are in separate clusters. It also allows nodes to determine when they can switch to sleep mode during operation. CFMA for mobile nodes provides fast association between the mobile node and the cluster coordinator. The proposed MAC performs well in both static and mobile scenarios, which shows its significance over existing MAC protocols proposed for mobile applications. The performance of CFMA is evaluated through extensive simulation, analysis and comparison with other mobility aware MAC protocols. The results show that CFMA outperforms significantly the existing CSMA/CA, Sensor Mac (S-MAC), Mobile MAC (MOB-MAC), Adaptive Mobility MAC (AM-MAC), Mobility Sensor MAC (MS-MAC), Mobility aware Delay sensitive MAC (MD-MAC) and Dynamic Sensor MAC (DS-MAC) protocols including throughput, latency and energy consumption.     

Using Sorted Switching Median Filter to remove high-density impulse noises

We propose a novel Sorted Switching Median Filter (i.e. SSMF) for effectively denoising extremely corrupted images while preserving the image details. The center pixel is considered as “uncorrupted” or “corrupted” noise in the detecting stage. The corrupted pixels that possess more noise-free surroundings will have higher processing priority in the SSMF sorting and filtering stages to rescue the heavily noisy neighbors. Five noise models are considered to assess the performance of the proposed SSMF algorithm. Several extensive simulation results conducted on both grayscale and color images with a wide range (from 10% to 90%) of noise corruption clearly show that the proposed SSMF substantially outperforms all other existing median-based filters.     

Deposition and characterization of molybdenum thin films using dc-plasma magnetron sputtering

Molebdenum (Mo) thin films were deposited on well-cleaned soda-lime glass substrates using DC-plasma magnetron sputtering. In the design of experiment deposition was optimized for maximum beneficial characteristics by monitoring effect of process variables such as deposition power (100–200 W). Their electrical, structural and morphological properties were analyzed to study the effect of these variables. The electrical resistivity of Mo thin films could be reduced by increasing deposition power. Within the range of analyzed deposition power, Mo thin films showed a mono crystalline nature and the crystallites were found to have an orientation along [110] direction. The surface morphology of thin films showed that a highly dense micro structure has been obtained. The surface roughness of films increased with deposition power. The adhesion of Mo thin films could be improved by increasing the deposition power. Atomic force microscopy was used for the topographical study of the films and to determine the roughness of the films. X-ray diffractrometer and scanning electron microscopy analysis were used to investigate the crystallinity and surface morphology of the films. Hall effect measurement system was used to find resistivity, carrier mobility and carrier density of deposited films. The adhesion test was performed using scotch hatch tape adhesion test. Mo thin films prepared at deposition power of 200 W, substrate temperature of 23°C and Ar pressure of 0.0123 mbar exhibited a mono crystalline structure with an orientation along (110) direction, thickness of ～550 nm and electrical resistivity value of 0.57 × 10^?4 Ω cm.