Accurate CAD-Model Analysis of Multilayer Microstrip Line on Anisotropic Substrate

Computationally efficient equivalent isotropic relative permittivity of the multilayer microstrip line on the uniaxial anisotropic substrate for 0 < w/h ≤ 10, anisotropic ratio0.5 ≤ n ≤ 3.0. Model has accuracy 0.5% against the full-wave method. It computes effective relative permittivity and characteristic impedance of microstrip on composite anisotropic substrates with deviation 4.5% respectively against the EM- software HFSS. Dispersion in multilayer anisotropic substrate microstrip up to mm wave range with high accuracy against the results of HFSS. The proposed models could be incorporated in the computer aided design for development of the components on the uniaxial anisotropic substrates.     

Storage and affinity properties of Murraya koenigii trypsin inhibitor

The Murraya Koenigii trypsin inhibitor was found to be the major protein component of the seed extract. The quantity of protein was determined to be approximately 20% of total protein extracted by simple buffer extraction. During different stages of seed development after flowering, the protein concentrations were found to be 5.27, 5.5, 8.5, 18.8 and 20% in 7, 19, 25, 37 and 55 days, respectively. During seed germination, protein degradations were observed from 20% to 12, 7 and 2% in 13, 16 and 22 days, respectively. This inhibitor, earlier purified using ion-exchange and gel filtration chromatography, was purified in single step by affinity column, using Cibacron blue 3GA, with substantial increase in yield. In partial internal sequencing by MALDI-TOF-TOF, six peptides of varying length, totalling 98 amino acid residues, exhibited similarities to the sequences from protease inhibitors, storage proteins and homeodomain-like proteins.     

Surface‐modified polysulfone membranes: Aqueous phase oxidation via persulfate radical

Polysulfone (Udel P1800) ultrafiltration membranes were surface modified using potassium persulfate (K₂S₂O₈) as a free radical source in the aqueous phase. The expected modification was hydrogen abstraction leading to hydroxylation at one or two sites on the isopropylidene linkage. Reaction time, K₂S₂O₈ concentration, and temperature were optimized based on two criteria: (1) minimal change in pure water fluxes after surface modification and (2) reduction of adsorptive fouling with a pulp mill effluent. The pure water flux retention for an unmodified membrane was ～20% after adsorptive fouling with the pulp mill effluent and was increased to 70% after reaction with K₂S₂O₈. Angle‐resolved XPS indicated increased oxygen and a new carbon peak consistent with an aldehyde reaction occurring in the top 3.5 nm. NMR solution analysis was inconclusive because of the low sensitivity of the experiment. Further analysis of oxidation products was carried out on finely dispersed polymer. Fourier transform infrared, internal reflection spectroscopy suggested oxidation by the formation of an aldehyde which was further oxidized to carboxylic acid. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1723–1730, 2006     

Superconducting State Parameters of MgB<Subscript>2</Subscript>: <Emphasis Type="Italic">Ab Initio</Emphasis> Study

Harrison’s first principle pseudopotential (HFPP) technique in conjunction with BCS theory and McMillan’s formalism has been used for the investigation of superconducting state parameters viz., Coulomb pseudopotential μ ^∗, electron–phonon coupling strength λ, SC transition temperature T _C , interaction strength N ₀ V, semi band gap Δ, energy or mass renormalization parameter Z ₀ and isotope effect exponent δ. The ground state properties of MgB₂ have also been calculated employing full-potential linearized augmented plane wave (FLAPW) method. This enables us to estimate the equilibrium values of bulk modulus and its pressure derivative through optimization of the crystal structure of the system. We have also described the total density of state (DOS) and the partial DOS (PDOS) around the Fermi energy.     

Modeling nonlinear thermo-elastic response for glassy polycarbonate using ultrasonic results under compression in a confined cell

We develop a nonlinear thermo-elastic model for polycarbonate (PC) using ultrasonic longitudinal and shear waves applied on a sample under confined compression. The model is a thermodynamically consistent model developed based on data obtained from a modified pressure-volume-temperature measurement system that also provides the longitudinal and shear wave moduli (Masubuchi et al., 1998. Materials Science Research International 4(3), 223-226). The heat capacity data was obtained by using a differential scanning calorimeter. The resulting model reproduces the ultrasonic behavior of the PC over the temperature range of 35 °C to 150 °C and under pressures from 0 to 70 MPa. Since the response at constant pressure is close to linear below the glass transition temperature of 147 °C, one may extend the use of the model to temperatures below 35 °C, possibly covering most of the range of use for most applications.     

Effect of Chemical Treatment on Thermal,Mechanical and Degradation Behavior of Banana Fiber Reinforced Polymer Composites

ABSTRACT

The current research endeavor, explores the thermal, mechanical, and degradation behavior of alkaline treated banana fibers reinforced polypropylene composites. Composites incorporating BF (20% w: w) treated with NaOH (5% w: v) aqueous solution were developed using extrusion-injection molding processes. After chemical treatment, the tensile, flexural and impact strength of the composite increases by 3.8%, 5.17%, and 11.50%, respectively. Scanning electron microscope (SEM) observations of tested specimens confirm the fiber pull out and fiber fracture as the main reasons for failure of developed composites under tensile and impact loading. The specimens were exposed to two different environments, water immersion and soil burial for 5 weeks for the degradation studies. The degradation behavior of composites was measured in terms of variation in weight and mechanical properties (tensile, flexural, and impact). The maximum degradation in mechanical properties was observed for the composites buried under soil. The composite lost 7.69%, 12.06%, and 3.27% of tensile, flexural, and impact strength, respectively.     

Gate leakage behavior of source/drain-to-gate non-overlapped MOSFET structure

In this paper, novel nanoscale MOSFET with Source/Drain-to-Gate Non-overlapped and high-k spacer structure has been demonstrated to reduce the gate leakage current for the first time. The gate leakage behavior of novel MOSFET structure has been investigated with help of compact analytical model and Sentaurus Simulation. Fringing gate electric field through the dielectric spacer induces inversion layer in the non-overlap region to act as extended source/drain region. It is found that optimal source/drain-to-gate non-overlapped and high-k spacer structure has reduced the gate leakage current to great extent as compared to those of an overlapped structure. Further, the proposed structure had improved off current, subthreshold slope and drain induced barrier lowering characteristic with a slight degradation in source/drain series resistance and effective gate capacitance.     

Simulation, scale-up and economics of adsorption and membrane based processes for isoflavones recovery

Laboratory scale adsorption and membrane based processes for the recovery of isoflavones from red clover flowers were reported earlier ( [Xu et al., 2005] and [Xu et al., 2006]). However, studies on scale-up and simulation for commercialization for both the methods have not been studied. In present study the economic feasibility of isoflavones recovery based on these two methods was investigated with a commercial bio-process simulator (SuperPro Designer^®). Laboratory scale separation data from previously published work was used in the simulations. Preliminary simulation studies confirmed the requirement of effluent streams recycling in order to reduce the production costs. Different flowsheets incorporating solvent recovery and recycle operations were designed and simulated to compare the economics of operation. Modified adsorption and membrane based processes incorporating recycling of waste streams were found to be economically more attractive than that of respective standard processes reported in the literature. The membrane process with solvent recycling had the lowest production cost of US$618/kg for isoflavones supplement. The adsorption-recycle process was found to be more expensive at US$1116/kg, while it had a higher content of isoflavones.     

Low profile coupling feed circularly polarized antennas for WLAN applications

This article presents two designs of circularly polarized antenna with simple circular‐shaped radiator and circular slotted ground plane. An arc‐shaped microstrip line coupling feed mechanism is used to excite the circular radiating patch. The 3‐dB axial ratio bandwidth of the proposed antenna‐1 and proposed antenna‐2 are 3.33% and 18%, respectively. The proposed design has several advantages such as easy matching, fabrication simplicity, compact size, and wide axial ratio bandwidth. Both the antennas have been designed on FR‐4 substrate with dielectric constant 4.4 and thickness 1.59 mm. Simulated and measured results are presented to validate the working of the proposed antennas.     

Wine: a potential source of antimicrobial compounds

With increase in the socioeconomic status, the demand of the health and nutraceutical food is increasing day-by-day. Wine contains a wide variety of the biologically active compounds including antimicrobial compounds (phenolics, acids, alcohols, bioamines, etc.) which possess the numerous health benefits. The concentration of these compounds changes according to the raw material their varieties and vinification process. Phenolics, such as epicatechin, gallic acid, catechin, caffeic acid, vannillic acid, p-coumaric acid and resveratrol, are present in different wines. Wine also contains various acids such as tartaric acid, succinic acid, acetic acid and malic acid. Alcohol includes majorly the ethanol with a minute quantity of methanol and other higher alcohols, whereas the bioamine includes the ethanolamine, ammonia and histamine. These all compounds have the ability to possess antimicrobial activity either independently or in the conjugative form with the other compounds. In this article, efforts have been made to document the different antimicrobial compounds present in wines and their antimicrobial activity. This review has the potential to attract readers; mainly researchers and industrialists for the future study and product development in the wine industry.