Abstract: The tensile properties of Mg-3%Al nanocrystalline
alloys were investigated at different test environment. Bulk
nanocrystalline samples of these alloy was successfully prepared by
mechanical alloying (MA) followed by cold compaction, sintering,
and hot extrusion process. The crystal size of the consolidated milled
sample was calculated by X-Ray line profile analysis. The
deformation mechanism and microstructural characteristic at
different test condition was discussed extensively. At room
temperature, relatively lower value of activation volume (AV) and
higher value of strain rate sensitivity (SRS) suggests that new rate
controlling mechanism accommodating plastic flow in the present
nanocrystalline sample. The deformation behavior and the
microstructural character of the present samples were discussed in
details.
Abstract: High level synthesis (HLS) is a process which
generates register-transfer level design for digital systems from
behavioral description. There are many HLS algorithms and
commercial tools. However, most of these algorithms consider a
behavioral description for the system when a single token is
presented to the system. This approach does not exploit extra
hardware efficiently, especially in the design of digital filters where
common operations may exist between successive tokens. In this
paper, we modify the behavioral description to process multiple
tokens in parallel. However, this approach is unlike the full
processing that requires full hardware replication. It exploits the
presence of common operations between successive tokens. The
performance of the proposed approach is better than sequential
processing and approaches that of full parallel processing as the
hardware resources are increased.
Abstract: The purpose of the present work was to study the
production and process parameters optimization for the synthesis of
cellulase from Trichoderma viride in solid state fermentation (SSF)
using an agricultural wheat straw as substrates; as fungal conversion
of lignocellulosic biomass for cellulase production is one among the
major increasing demand for various biotechnological applications.
An optimization of process parameters is a necessary step to get
higher yield of product. Several kinetic parameters like pretreatment,
extraction solvent, substrate concentration, initial moisture content,
pH, incubation temperature and inoculum size were optimized for
enhanced production of third most demanded industrially important
cellulase. The maximum cellulase enzyme activity 398.10±2.43
μM/mL/min was achieved when proximally analyzed lignocellulosic
substrate wheat straw inocubated at 2% HCl as pretreatment tool
along with distilled water as extraction solvent, 3% substrate
concentration 40% moisture content with optimum pH 5.5 at 45°C
incubation temperature and 10% inoculum size.
Abstract: In this study, ZnO nano rods and ZnO ultrafine particles were synthesized by Gel-casting method. The synthesized ZnO powder has a hexagonal zincite structure. The ZnO aggregates with rod-like morphology are typically 1.4 μm in length and 120 nm in diameter, which consist of many small nanocrystals with diameters of 10 nm. Longer wires connected by many hexahedral ZnO nanocrystals were obtained after calcinations at the temperature over 600° C.The crystalline structures and morphologies of the powder have been characterized by X-ray diffraction(XRD) and Scaning electron microscopy (SEM).The result shows that the different preparation conditions such as concentration H2O, calcinations time and calcinations temperature have a lot of influences upon the properties of nano ZnO powders, an increase in the temperature of the calcinations results in an increase of the grain size and also the increase of the calcinations time in high temperature makes the size of the grains bigger. The existences of extra watter prevent nano grains from improving like rod morphology. We have obtained the smallest grain size of ZnO powder by controlling the process conditions. Finally In a suitable condition, a novel nanostructure, namely bi-rod-like ZnO nano rods was found which is different from known ZnO nanostructures.
Abstract: In industrial scale of Gas to Liquid (GTL) process in
Fischer-Tropsch (FT) synthesis, a part of reactor outlet gases such as
CO2 and CH4 as side reaction products, is usually recycled. In this
study, the influence of CO2 and CH4 on the performance and
selectivity of Co-Ru/Al2O3 catalyst is investigated by injection of
these gases (0-20 vol. % of feed) to the feed stream. The effect of
temperature and feed flow rate, are also inspected. The results show
that low amounts of CO2 in the feed stream, doesn`t change the
catalyst activity significantly but increasing the amount of CO2 (more
than 10 vol. %) cause the CO conversion to decrease and the
selectivity of heavy components to increase. Methane acts as an inert
gas and doesn`t affect the catalyst performance. Increasing feed flow
rate has negative effect on both CO conversion and heavy component
selectivity. By raising the temperature, CO conversion will increase
but there are more volatile components in the product. The effect of
CO2 on the catalyst deactivation is also investigated carefully and a
mechanism is suggested to explain the negative influence of CO2 on
catalyst deactivation.
Abstract: Mitochondria are dynamic organelles, capable to
interact with each other. While the number of mitochondria in a cell
varies, their quality and functionality depends on the operation of
fusion, fission, motility and mitophagy. Nowadays, several
researches declare as an important factor in neurogenerative diseases
the disruptions in the regulation of mitochondrial dynamics. In this
paper a stochastic model in BioAmbients calculus is presented,
concerning mitochondrial fusion and its distribution in the renewal of
mitochondrial population in a cell. This model describes the
successive and dependent stages of protein synthesis, protein-s
activation and merging of two independent mitochondria.
Abstract: Commercially available lipases (Candida antarctica lipase B, Novozyme 435, Thermomyces lanuginosus lipase, and Lipozyme TL IM), as well as sol-gel immobilized lipases, have been screened for their ability to acylate regioselectively xylitol, sorbitol, and mannitol with a phenolic ester in a binary mixture of t-butanol and dimethylsulfoxide. HPLC and MALDI-TOF MS analysis revealed the exclusive formation of monoesters for all studied sugar alcohols. The lipases immobilized by the sol-gel entrapment method proved to be efficient catalysts, leading to high conversions (up to 60%) in the investigated acylation reactions. From a sequence of silane precursors with different nonhydrolyzable groups in their structure, the presence of octyl and i-butyl group was most beneficial for the catalytic activity of sol-gel entrapped lipases in the studied process.
Abstract: Polymer-like organic thin films were deposited on both
aluminum alloy type 6061 and glass substrates at room temperature by
Plasma Enhanced Chemical Vapor Deposition (PECVD) methodusing
benzene and hexamethyldisiloxane (HMDSO) as precursor materials.
The surface and physical properties of plasma-polymerized organic
thin films were investigated at different r.f. powers. The effects of
benzene/argon ratio on the properties of plasma polymerized benzene
films were also investigated. It is found that using benzene alone
results in a non-coherent and non-adherent powdery deposited
material. The chemical structure and surface properties of the asgrown
plasma polymerized thin films were analyzed on glass
substrates with FTIR and contact angle measurements. FTIR spectra
of benzene deposited film indicated that the benzene rings are
preserved when increasing benzene ratio and/or decreasing r.f.
powers. FTIR spectra of HMDSO deposited films indicated an
increase of the hydrogen concentration and a decrease of the oxygen
concentration with the increase of r.f. power. The contact angle (θ) of
the films prepared from benzene was found to increase by about 43%
as benzene ratio increases from 10% to 20%. θ was then found to
decrease to the original value (51°) when the benzene ratio increases
to 100%. The contact angle, θ, for both benzene and HMDSO
deposited films were found to increase with r.f. power. This signifies
that the plasma polymerized organic films have substantially low
surface energy as the r.f power increases. The corrosion resistance of
aluminum alloy substrate both bare and covered with plasma
polymerized thin films was carried out by potentiodynamic
polarization measurements in standard 3.5 wt. % NaCl solution at
room temperature. The results indicate that the benzene and HMDSO
deposited films are suitable for protection of the aluminum substrate
against corrosion. The changes in the processing parameters seem to
have a strong influence on the film protective ability. Surface
roughness of films deposited on aluminum alloy substrate was
investigated using scanning electron microscopy (SEM). The SEM
images indicate that the surface roughness of benzene deposited films
increase with decreasing the benzene ratio. SEM images of benzene
and HMDSO deposited films indicate that the surface roughness
decreases with increasing r.f. power. Studying the above parameters
indicate that the films produced are suitable for specific practical
applications.
Abstract: The carbon based coils with the nanometer scale have
the 3 dimension helix geometry. We synthesized the carbon nano-coils
by the use of chemical vapor deposition technique with iron and tin as
the catalysts. The fabricated coils have the external diameter of
ranging few hundred nm to few thousand nm. The Scanning
Electro-Microscope (SEM) and Tunneling Electro-Microscope has
shown detail images of the coil-s structure. The fabrication of the
carbon nano-coils can be grown on the metal and non-metal substrates,
such as the stainless steel and silicon substrates. Besides growth on the
flat substrate; they also can be grown on the stainless steel wires. After
the synthesis of the coils, the mechanical and electro-mechanical
property is measured. The experimental results were reported.
Abstract: A process flowsheet was developed in ChemCad 6.4
to study the effect of feed moisture contents on the pre-esterification
of waste oils. Waste oils were modelled as a mixture of triolein
(90%), oleic acid (5%) and water (5%). The process mainly consisted
of feed drying, pre-esterification reaction and methanol recovery. The
results showed that the process energy requirements would be
minimized when higher degrees of feed drying and higher preesterification
reaction temperatures are used.
Abstract: Novel polystrene-bound Schiff bases and their Pt(IV)
complexes have been prepared from condensation reaction of
polystyrene-A-NH2 with 2-hydroxybenzaldehyde and 5-fluoro-3-
bromo-2-hydroxybenzaldehyde. The structures of Pt(IV) complexes
with polystyrene including Schiff bases have been determined by
elemental analyses, magnetic susceptibility, IR, 1H-NMR, UV-vis,
TG/DTA and AAS. The antibacterial and antifungal activities of the
synthesized compounds have been studied by the well-diffusion
method against some selected microorganisms: (Bacillus cereus spp.,
Listeria monocytogenes 4b, Micrococcus luteus, Staphylococcus
aureus, Staphylococcus epidermis, Brucella abortus, Escherichia
coli, Pseudomonas putida spp., Shigella dysenteria type 10,
Salmonella typhi H).
Abstract: The growth of open networks created the interest to commercialise it. The establishment of an electronic business mechanism must be accompanied by a digital-electronic payment system to transfer the value of transactions. Financial organizations are requested to offer a secure e-payment synthesis with equivalent levels of trust and security served in conventional paper-based payment transactions. The paper addresses the challenge of the first trade problem in e-commerce, provides a brief literature review on electronic payment and attempts to explain the underlying concept and method of trust in relevance to electronic payment.
Abstract: This paper deals with the synthesis of fuzzy state feedback controller of induction motor with optimal performance. First, the Takagi-Sugeno (T-S) fuzzy model is employed to approximate a non linear system in the synchronous d-q frame rotating with electromagnetic field-oriented. Next, a fuzzy controller is designed to stabilise the induction motor and guaranteed a minimum disturbance attenuation level for the closed-loop system. The gains of fuzzy control are obtained by solving a set of Linear Matrix Inequality (LMI). Finally, simulation results are given to demonstrate the controller-s effectiveness.
Abstract: In this paper, taking Chinese Nanjing Metro ALSTOM vehicle synthesis brake as an example, the subway with synthetic brake shoe formula components of final product performance, has done a lot of research and performance test, final is drawn with hybrid fiber as reinforcing material, modified phenolic resin as matrix material, and then filling friction modifier performance, by the hot pressing process made a new type of domestic subway brake shoe. The product of the test performance indicators that can replace the similar foreign products.
Abstract: Response Surface Methodology (RSM) is a powerful
and efficient mathematical approach widely applied in the
optimization of cultivation process. Cellulase enzyme production by
Trichoderma reesei RutC30 using agricultural waste rice straw and
banana fiber as carbon source were investigated. In this work,
sequential optimization strategy based statistical design was
employed to enhance the production of cellulase enzyme through
submerged cultivation. A fractional factorial design (26-2) was applied
to elucidate the process parameters that significantly affect cellulase
production. Temperature, Substrate concentration, Inducer
concentration, pH, inoculum age and agitation speed were identified
as important process parameters effecting cellulase enzyme synthesis.
The concentration of lignocelluloses and lactose (inducer) in the
cultivation medium were found to be most significant factors. The
steepest ascent method was used to locate the optimal domain and a
Central Composite Design (CCD) was used to estimate the quadratic
response surface from which the factor levels for maximum
production of cellulase were determined.
Abstract: This paper deals with the optimal design of two-channel recursive parallelogram quadrature mirror filter (PQMF) banks. The analysis and synthesis filters of the PQMF bank are composed of two-dimensional (2-D) recursive digital all-pass filters (DAFs) with nonsymmetric half-plane (NSHP) support region. The design problem can be facilitated by using the 2-D doubly complementary half-band (DC-HB) property possessed by the analysis and synthesis filters. For finding the coefficients of the 2-D recursive NSHP DAFs, we appropriately formulate the design problem to result in an optimization problem that can be solved by using a weighted least-squares (WLS) algorithm in the minimax (L∞) optimal sense. The designed 2-D recursive PQMF bank achieves perfect magnitude response and possesses satisfactory phase response without requiring extra phase equalizer. Simulation results are also provided for illustration and comparison.
Abstract: The influence of copper promoters and reaction
conditions on the formation of alcohols byproducts of a common
Fischer-Tropsch synthesis used iron-based catalysts were investigated.
A good compromise of 28%Cu/FeKLaSiO2 can lead to the
optimization of an improved Fischer-Tropsch catalyst. The product
distribution shifts towards hydrocarbons with increasing the reaction
temperature, while pressure promotes the formation of alcohols. It was
found that the production of either alcohols or hydrocarbons followed
A-S-F distributions, and their α parameters were essentially different
which indicated a competition in the growing chain between the two
species. TPD after acetaldehyde adsorption gave strong evidence of
the insertion of a C1 oxygen-containing species into an alkyl chain.
Abstract: Designing and implementing intelligent systems has become a crucial factor for the innovation and development of better products of space technologies. A neural network is a parallel system, capable of resolving paradigms that linear computing cannot. Field programmable gate array (FPGA) is a digital device that owns reprogrammable properties and robust flexibility. For the neural network based instrument prototype in real time application, conventional specific VLSI neural chip design suffers the limitation in time and cost. With low precision artificial neural network design, FPGAs have higher speed and smaller size for real time application than the VLSI and DSP chips. So, many researchers have made great efforts on the realization of neural network (NN) using FPGA technique. In this paper, an introduction of ANN and FPGA technique are briefly shown. Also, Hardware Description Language (VHDL) code has been proposed to implement ANNs as well as to present simulation results with floating point arithmetic. Synthesis results for ANN controller are developed using Precision RTL. Proposed VHDL implementation creates a flexible, fast method and high degree of parallelism for implementing ANN. The implementation of multi-layer NN using lookup table LUT reduces the resource utilization for implementation and time for execution.
Abstract: The worldwide prevalence of H3N2 influenza virus
and its increasing resistance to the existing drugs necessitates for the
development of an improved/better targeting anti-influenza drug.
H3N2 influenza neuraminidase is one of the two membrane-bound
proteins belonging to group-2 neuraminidases. It acts as key player
involved in viral pathogenicity and hence, is an important target of
anti-influenza drugs. Oseltamivir is one of the potent drugs targeting
this neuraminidase. In the present work, we have taken subtype N2
neuraminidase as the receptor and probable analogs of oseltamivir as
drug molecules to study the protein-drug interaction in anticipation of
finding efficient modified candidate compound. Oseltamivir analogs
were made by modifying the functional groups using Marvin Sketch
software and were docked using Schrodinger-s Glide. Oseltamivir
analog 10 was detected to have significant energy value (16% less
compared to Oseltamivir) and could be the probable lead molecule. It
infers that some of the modified compounds can interact in a novel
manner with increased hydrogen bonding at the active site of
neuraminidase and it might be better than the original drug. Further
work can be carried out such as enzymatic inhibition studies;
synthesis and crystallizing the drug-target complex to analyze the
interactions biologically.
Abstract: In this paper 2D Simulation of catalytic Fixed Bed Reactor in Fischer-Tropsch Synthesis of GTL technology has been performed utilizing computational fluid dynamics (CFD). Synthesis gas (a mixture of carbon monoxide and hydrogen) has been used as feedstock. The reactor was modeled and the model equations were solved employing finite volume method. The model was validated against the experimental data reported in literature. The comparison showed a good agreement between simulation results and the experimental data. In addition, the model was applied to predict the concentration contours of the reactants and products along the length of reactor.