Abstract: Several trillion cigarettes produced worldwide annually lead to many thousands of kilograms of toxic waste. Cigarette butts (CBs) accumulate in the environment due to the poor biodegradability of the cellulose acetate filters. This paper presents some of the results from a continuing study on recycling CBs into fired clay bricks. Physico-mechanical properties of fired clay bricks manufactured with different percentages of CBs are reported and discussed. The results show that the density of fired bricks was reduced by up to 30 %, depending on the percentage of CBs incorporated into the raw materials. Similarly, the compressive strength of bricks tested decreased according to the percentage of CBs included in the mix. The thermal conductivity performance of bricks was improved by 51 and 58 % for 5 and 10 % CBs content respectively. Leaching tests were carried out to investigate the levels of possible leachates of heavy metals from the manufactured clay-CB bricks. The results revealed trace amounts of heavy metals.
Abstract: The zinc and iron environments in different growth
stages have been studied with EXAFS and XANES with Brookhaven
Synchrotron Light Source. Tissue samples included meat, organ,
vegetable, leaf, and yeast. The project studied the EXAFS and
XANES of tissue samples using Zn and Fe K-edges. Duck embryo
samples show that brain and intestine would contain shorter EXFAS
determined Zn-N/O bond; as with the cases of fresh yeast versus
reconstituted live yeast and green leaf versus yellow leaf. The
XANES Fourier transform characteristic-length would be useful as a
functionality index for selected types of tissue samples in various
physical states. The extension to the development of functional
synchrotron imaging for tissue engineering application based on
spectroscopic technique is discussed.
Abstract: The mineral having chemical compositional formula MgAl2O4 is called “spinel". The ferrites crystallize in spinel structure are known as spinel-ferrites or ferro-spinels. The spinel structure has a fcc cage of oxygen ions and the metallic cations are distributed among tetrahedral (A) and octahedral (B) interstitial voids (sites). The X-ray diffraction (XRD) intensity of each Bragg plane is sensitive to the distribution of cations in the interstitial voids of the spinel lattice. This leads to the method of determination of distribution of cations in the spinel oxides through XRD intensity analysis. The computer program for XRD intensity analysis has been developed in C language and also tested for the real experimental situation by synthesizing the spinel ferrite materials Mg0.6Zn0.4AlxFe2- xO4 and characterized them by X-ray diffractometry. The compositions of Mg0.6Zn0.4AlxFe2-xO4(x = 0.0 to 0.6) ferrites have been prepared by ceramic method and powder X-ray diffraction patterns were recorded. Thus, the authenticity of the program is checked by comparing the theoretically calculated data using computer simulation with the experimental ones. Further, the deduced cation distributions were used to fit the magnetization data using Localized canting of spins approach to explain the “recovery" of collinear spin structure due to Al3+ - substitution in Mg-Zn ferrites which is the case if A-site magnetic dilution and non-collinear spin structure. Since the distribution of cations in the spinel ferrites plays a very important role with regard to their electrical and magnetic properties, it is essential to determine the cation distribution in spinel lattice.
Abstract: This paper concerns about the experimental and
numerical investigations of energy absorption and axial tearing
behaviour of aluminium 6060 circular thin walled tubes under static
axial compression. The tubes are received in T66 heat treatment
condition with fixed outer diameter of 42mm, thickness of 1.5mm
and length of 120mm. The primary variables are the conical die
angles (15°, 20° and 25°). Numerical simulations are carried on
ANSYS/LS-DYNA software tool, for investigating the effect of
friction between the tube and the die.
Abstract: There are many kinds of metal borates found not only
in nature but also synthesized in the laboratory such as magnesium
borates. Due to its excellent properties, as remarkable ceramic
materials, they have also application areas in anti-wear and friction
reducing additives as well as electro-conductive treating agents. The
synthesis of magnesium borate powders can be fulfilled simply with
two different methods, hydrothermal and thermal synthesis.
Microwave assisted method, also another way of producing
magnesium borate, can be classified into thermal synthesis because of
using the principles of solid state synthesis. It also contributes
producing particles with small size and high purity in nano-size
material synthesize. In this study the production of magnesium
borates, are aimed using MgCl2.6H2O and H3BO3. The identification
of both starting materials and products were made by the equipments
of, X-Ray Diffraction (XRD) and Fourier Transform Infrared
Spectroscopy (FT-IR). After several synthesis steps magnesium
borates were synthesized and characterized by XRD and FT-IR, as
well.
Abstract: Matrix metalloproteinase-3 (MMP3) is key member
of the MMP family, and is known to be present in coronary
atherosclerotic. Several studies have demonstrated that MMP-3
5A/6A polymorphism modify each transcriptional activity in allele
specific manner. We hypothesized that this polymorphism may play
a role as risk factor for development of coronary stenosis. The aim of
our study was to estimate MMP-3 (5A/6A) gene polymorphism on
interindividual variability in risk for coronary stenosis in an Iranian
population.DNA was extracted from white blood cells and genotypes
were obtained from coronary stenosis cases (n=95) and controls
(n=100) by PCR (polymerase chain reaction) and restriction
fragment length polymorphism techniques. Significant differences
between cases and controls were observed for MMP3 genotype
frequencies (X2=199.305, p< 0.001); the 6A allele was less
frequently seen in the control group, compared to the disease group
(85.79 vs. 78%, 6A/6A+5A/6A vs. 5A/5A, P≤0.001). These data
imply the involvement of -1612 5A/6A polymorphism in coronary
stenosis, and suggest that probably the 6A/6A MMP-3 genotype is a
genetic susceptibility factor for coronary stenosis.
Abstract: carbonylation of methanol in homogenous phase is
one of the major routesfor production of acetic acid. Amongst group
VIII metal catalysts used in this process iridium has displayed the
best capabilities. To investigate effect of operating parameters like:
temperature, pressure, methyl iodide, methyl acetate, iridium,
ruthenium, and water concentrations on the reaction rate,
experimental design for this system based upon central composite
design (CCD) was utilized. Statistical rate equation developed by this
method contained individual, interactions and curvature effects of
parameters on the reaction rate. The model with p-value less than
0.0001 and R2 values greater than 0.9; confirmeda satisfactory fitness
of the experimental and theoretical studies. In other words, the
developed model and experimental data obtained passed all
diagnostic tests establishing this model as a statistically significant.
Abstract: In this study, the Taguchi method was used to optimize the effect of HALO structure or halo implant variations on threshold voltage (VTH) and leakage current (ILeak) in 45nm p-type Metal Oxide Semiconductor Field Effect Transistors (MOSFETs) device. Besides halo implant dose, the other process parameters which used were Source/Drain (S/D) implant dose, oxide growth temperature and silicide anneal temperature. This work was done using TCAD simulator, consisting of a process simulator, ATHENA and device simulator, ATLAS. These two simulators were combined with Taguchi method to aid in design and optimize the process parameters. In this research, the most effective process parameters with respect to VTH and ILeak are halo implant dose (40%) and S/D implant dose (52%) respectively. Whereas the second ranking factor affecting VTH and ILeak are oxide growth temperature (32%) and halo implant dose (34%) respectively. The results show that after optimizations approaches is -0.157V at ILeak=0.195mA/μm.
Abstract: We have measured the pressure drop and convective
heat transfer coefficient of water – based AL(25nm),AL2O3(30nm)
and CuO(50nm) Nanofluids flowing through a uniform heated
circular tube in the fully developed laminar flow regime. The
experimental results show that the data for Nanofluids friction factor
show a good agreement with analytical prediction from the Darcy's
equation for single-phase flow. After reducing the experimental
results to the form of Reynolds, Rayleigh and Nusselt numbers. The
results show the local Nusselt number and temperature have
distribution with the non-dimensional axial distance from the tube
entry. Study decided that thenNanofluid as Newtonian fluids through
the design of the linear relationship between shear stress and the rate
of stress has been the study of three chains of the Nanofluid with
different concentrations and where the AL, AL2O3 and CuO – water
ranging from (0.25 - 2.5 vol %). In addition to measuring the four
properties of the Nanofluid in practice so as to ensure the validity of
equations of properties developed by the researchers in this area and
these properties is viscosity, specific heat, and density and found that
the difference does not exceed 3.5% for the experimental equations
between them and the practical. The study also demonstrated that the
amount of the increase in heat transfer coefficient for three types of
Nano fluid is AL, AL2O3, and CuO – Water and these ratios are
respectively (45%, 32%, 25%) with insulation and without insulation
(36%, 23%, 19%), and the statement of any of the cases the best
increase in heat transfer has been proven that using insulation is
better than not using it. I have been using three types of Nano
particles and one metallic Nanoparticle and two oxide Nanoparticle
and a statement, whichever gives the best increase in heat transfer.
Abstract: The previous study of new metal gasket that contact
width and contact stress an important design parameter for optimizing
metal gasket performance. The optimum design based on an elastic
and plastic contact stress was founded. However, the influence of
flange surface roughness had not been investigated thoroughly. The
flange has many kinds of surface roughness. In this study, we
conducted a gasket model include a flange surface roughness effect. A
finite element method was employed to develop simulation solution. A
uniform quadratic mesh used for meshing the gasket material and a
gradually quadrilateral mesh used for meshing the flange. The gasket
model was simulated by using two simulation stages which is forming
and tightening simulation. A simulation result shows that a smoother
of surface roughness has higher slope for force per unit length. This
mean a squeezed against between flange and gasket will be strong. The
slope of force per unit length for gasket 400-MPa mode was higher
than the gasket 0-MPa mode.
Abstract: In this paper, we have proposed two novel plasmonic demultiplexing structures based on metal-insulator-metal surfaces which, beside their compact size, have a very good transmission spectrum. The impact of the key internal parameters on the transmission spectrum is numerically analyzed by using the twodimensional (2D) finite difference time domain (FDTD) method. The proposed structures could be used to develop ultra-compact photonic wavelength demultiplexing devices for large-scale photonic integration.
Abstract: Small cracks or chips of a product appear very
frequently in the course of continuous production of an automatic
press process system. These phenomena become the cause of not only
defective product but also damage of a press mold. In order to solve
this problem AE system was introduced. AE system was expected to
be very effective to real time detection of the defective product and to
prevention of the damage of the press molds.
In this study, for pick and analysis of AE signals generated from the
press process, AE sensors/pre-amplifier/analysis and processing board
were used as frequently found in the other similar cases. For analysis
and processing the AE signals picked in real time from the good or bad
products, specialized software called cdm8 was used. As a result of
this work it was conformed that intensity and shape of the various AE
signals differ depending on the weight and thickness of metal sheet
and process type.
Abstract: Intermetallic Ni3Al – based alloys belong to a group
of advanced materials characterized by good chemical and physical
properties (such as structural stability, corrosion resistance) which
offer advenced technological applications. The paper presents the
study of catalytic properties of Ni3Al foils (thickness approximately
50 &m) in the methanol and hexane decomposition. The egzamined
material posses microcrystalline structure without any additional
catalysts on the surface. The better catalytic activity of Ni3Al foils
with respect to quartz plates in both methanol and hexane
decomposition was confirmed. On thin Ni3Al foils the methanol
conversion reaches approximately 100% above 480 oC while the
hexane conversion reaches approximately 100% (98,5%) at 500 oC.
Deposit formed during the methanol decomposition is built up of
carbon nanofibers decorated with metal-like nanoparticles.
Abstract: The use of hard and brittle material has become
increasingly more extensive in recent years. Therefore processing of
these materials for the parts fabrication has become a challenging
problem. However, it is time-consuming to machine the hard brittle
materials with the traditional metal-cutting technique that uses
abrasive wheels. In addition, the tool would suffer excessive wear as
well. However, if ultrasonic energy is applied to the machining
process and coupled with the use of hard abrasive grits, hard and
brittle materials can be effectively machined. Ultrasonic machining
process is mostly used for the brittle materials. The present research
work has developed models using finite element approach to predict
the mechanical stresses sand strains produced in the tool during
ultrasonic machining process. Also the flow behavior of abrasive
slurry coming out of the nozzle has been studied for simulation using
ANSYS CFX module. The different abrasives of different grit sizes
have been used for the experimentation work.
Abstract: The hydrogen peroxide treatment was able to
remediate chlorophenols, polycyclic aromatic hydrocarbons, diesel
and transformer oil contaminated soil. Chemical treatment of
contaminants adsorbed in peat resulted in lower contaminants-
removal and required higher addition of chemicals than the treatment
of contaminants in sand. The hydrogen peroxide treatment was found
to be feasible for soil remediation at natural soil pH. Contaminants in
soil could degrade with the addition of hydrogen peroxide only
indicating the ability of transition metals ions and minerals of these
metals presented in soil to catalyse the reaction of hydrogen peroxide
decomposition.
Abstract: Metal stamping die design is a complex, experiencebased
and time-consuming task. Various artificial intelligence (AI)
techniques are being used by worldwide researchers for stamping die
design to reduce complexity, dependence on human expertise and
time taken in design process as well as to improve design efficiency.
In this paper a comprehensive review of applications of AI
techniques in manufacturability evaluation of sheet metal parts, die
design and process planning of metal stamping die is presented.
Further the salient features of major research work published in the
area of metal stamping are presented in tabular form and scope of
future research work is identified.
Abstract: The chemical degradation of dieldrin in ferric
sulfide and iron powder aqueous suspension was investigated
in laboratory batch type experiments. To identify the reaction
mechanism, reduced copper was used as reductant. More than
90% of dieldrin was degraded using both reaction systems after
29 days. Initial degradation rate of the pesticide using ferric
sulfide was superior to that using iron powder. The reaction
schemes were completely dissimilar even though the ferric ion
plays an important role in both reaction systems. In the case of
metallic iron powder, dieldrin undergoes partial dechlorination.
This reaction proceeded by reductive hydrodechlorination with
the generation of H+, which arise by oxidation of ferric iron.
This reductive reaction was accelerated by reductant but
mono-dechlorination intermediates were accumulated. On the
other hand, oxidative degradation was observed in the reaction
with ferric sulfide, and the stable chemical structure of dieldrin
was decomposed into water-soluble intermediates. These
reaction intermediates have no chemical structure of drin class.
This dehalogenation reaction assumes to occur via the adsorbed
hydroxyl radial generated on the surface of ferric sulfide.
Abstract: Mining tailings represent a generating source of rich heavy metal material with a potential danger the public health and the environment, since these metals, under certain conditions, can leach and contaminate aqueous systems that serve like supplying potable water sources. The strategy for this work is based on the observation, experimentation and the simulation that can be obtained by binding real answers of the hydrodynamic behavior of metals leached from mining tailings, and the applied mathematics that provides the logical structure to decipher the individual effects of the general physicochemical phenomenon. The case of study presented herein focuses on mining tailings deposits located in Monte San Nicolas, Guanajuato, Mexico, an abandoned mine. This was considered the contamination source that under certain physicochemical conditions can favor the metal leaching, and its transport towards aqueous systems. In addition, the cartography, meteorology, geology and the hydrodynamics and hydrological characteristics of the place, will be helpful in determining the way and the time in which these systems can interact. Preliminary results demonstrated that arsenic presents a great mobility, since this one was identified in several superficial aqueous systems of the micro watershed, as well as in sediments in concentrations that exceed the established maximum limits in the official norms. Also variations in pH and potential oxide-reduction were registered, conditions that favor the presence of different species from this element its solubility and therefore its mobility.
Abstract: In this paper we have developed a FDTD simulation
code which can treat wave propagation of a monopole antenna in a
metallic case which covers with PML, and performed a series of three
dimensional FDTD simulations of electromagnetic wave propagation
in this space .We also provide a measurement set up in antenna lab
and fortunately the simulations and measurements show good
agreement. According to simulation and measurement results, we
confirmed that the computer program which had been written in
FORTRAN, works correctly.
Abstract: Abrasive Jet Machining is an Unconventional
machining process in which the metal is removed from brittle and
hard material in the form of micro-chips. With increase in need of
materials like ceramics, composites, in manufacturing of various
Mechanical & Electronic components, AJM has become a useful
technique for micro machining. The present study highlights the
influence of different parameters like Pressure, SOD, Time, Abrasive
grain size, nozzle diameter on the Metal removal of FRP (Fiber
Reinforced Polymer) composite by Abrasive jet machining. The
results of the Experiments conducted were analyzed and optimized
with TAGUCHI method of Optimization and ANOVA for Optimal
Value.