Abstract: The presence of toxic heavy metals in industrial
effluents is one of the serious threats to the environment. Heavy
metals such as Cadmium, Chromium, Lead, Nickel, Zinc, Mercury,
Copper, Arsenic are found in the effluents of industries such as
foundries, electroplating, petrochemical, battery manufacturing,
tanneries, fertilizer, dying, textiles, metallurgical and metal finishing.
Tremendous increase of industrial copper usage and its presence in
industrial effluents has lead to a growing concern about the fate and
effects of Copper in the environment. Percolation of industrial
effluents through soils leads to contamination of ground water and
soils. The transport of heavy metals and their diffusion into the soils
has therefore, drawn the attention of the researchers.
In this study, an attempt has been made to delineate the
mechanisms of transport and fate of copper in terrestrial
environment. Column studies were conducted using perplex glass
square column of dimension side 15 cm and 1.35 m long. The soil
samples were collected from a natural drain near Mohali (India). The
soil was characterized to be poorly graded sandy loam. The soil was
compacted to the field dry density level of about 1.6 g/cm3. Break
through curves for different depths of the column were plotted. The
results of the column study indicated that the copper has high
tendency to flow in the soils and fewer tendencies to get absorbed on
the soil particles. The t1/2 estimates obtained from the studies can be
used for design copper laden wastewater disposal systems.
Abstract: RC4 was used as an encryption algorithm in WEP(Wired Equivalent Privacy) protocol that is a standardized for 802.11 wireless network. A few attacks followed, indicating certain weakness in the design. In this paper, we proposed a new variant of RC4 stream cipher. The new version of the cipher does not only appear to be more secure, but its keystream also has large period, large complexity and good statistical properties.
Abstract: A novel circuit for generating a signal embedded with
features about data from three sensors is presented. This suggested
circuit is making use of a resistance-to-time converter employing a
bridge amplifier, an integrator and a comparator. The second resistive
sensor (Rz) is transformed into duty cycle. Another bridge with
varying resistor, (Ry) in the feedback of an OP AMP is added in
series to change the amplitude of the resulting signal in a proportional
relationship while keeping the same frequency and duty cycle
representing proportional changes in resistors Rx and Rz already
mentioned. The resultant output signal carries three types of
information embedded as variations of its frequency, duty cycle and
amplitude.
Abstract: This paper presents a NDT by infrared thermography with excitation CO2 Laser, wavelength of 10.6 μm. This excitation is the controllable heating beam, confirmed by a preliminary test on a wooden plate 1.2 m x 0.9 m x 1 cm. As the first practice, this method is applied to detecting the defect in CFRP heated by the Laser 300 W during 40 s. Two samples 40 cm x 40 cm x 4.5 cm are prepared, one with defect, another one without defect. The laser beam passes through the lens of a deviation device, and heats the samples placed at a determinate position and area. As a result, the absence of adhesive can be detected. This method displays prominently its application as NDT with the composite materials. This work gives a good perspective to characterize the laser beam, which is very useful for the next detection campaigns.
Abstract: Magnetic Resonance Imaging play a vital role in the decision-diagnosis process of brain MR images. For an accurate diagnosis of brain related problems, the experts mostly compares both T1 and T2 weighted images as the information presented in these two images are complementary. In this paper, rotational and translational invariant form of Local binary Pattern (LBP) with additional gray scale information is used to retrieve similar slices of T1 weighted images from T2 weighted images or vice versa. The incorporation of additional gray scale information on LBP can extract more local texture information. The accuracy of retrieval can be improved by extracting moment features of LBP and reweighting the features based on users feedback. Here retrieval is done in a single subject scenario where similar images of a particular subject at a particular level are retrieved, and multiple subjects scenario where relevant images at a particular level across the subjects are retrieved.
Abstract: In this paper we present a noise reduction filter for video processing. It is based on the recently proposed two dimensional steering kernel, extended to three dimensions and further augmented to suit the spatial-temporal domain of video processing. Two alternative filters are proposed - the time symmetric kernel and the time asymmetric kernel. The first reduces the noise on single sequences, but to handle the problems at scene shift the asymmetric kernel is introduced. The performance of both are tested on simulated data and on a real video sequence together with the existing steering kernel. The proposed kernels improves the Rooted Mean Squared Error (RMSE) compared to the original steering kernel method on video material.
Abstract: The removal of hydrogen sulphide is required for reasons of health, odour problems, safety and corrosivity problems. The means of removing hydrogen sulphide mainly depend on its concentration and kind of medium to be purified. The paper deals with a method of hydrogen sulphide removal from the air by its catalytic oxidation to elemental sulphur with the use of Fe-EDTA complex. The possibility of obtaining fibrous filtering materials able to remove small concentrations of H2S from the air were described. The base of these materials is fibrous ion exchanger with Fe(III)- EDTA complex immobilized on their functional groups. The complex of trivalent iron converts hydrogen sulphide to elemental sulphur. Bivalent iron formed in the reaction is oxidized by the atmospheric oxygen, so complex of trivalent iron is continuously regenerated and the overall process can be accounted as pseudocatalytic. In the present paper properties of several fibrous catalysts based on ion exchangers with different chemical nature (weak acid,weak base and strong base) were described. It was shown that the main parameters affecting the process of catalytic oxidation are:concentration of hydrogen sulphide in the air, relative humidity of the purified air, the process time and the content of Fe-EDTA complex in the fibres. The data presented show that the filtering layers with anion exchange package are much more active in the catalytic processes of hydrogen sulphide removal than cation exchanger and inert materials. In the addition to the nature of the fibres relative air humidity is a critical factor determining efficiency of the material in the air purification from H2S. It was proved that the most promising carrier of the Fe-EDTA catalyst for hydrogen sulphide oxidation are Fiban A-6 and Fiban AK-22 fibres.
Abstract: Due to the high percentage of induction motors in industrial market, there exist a large opportunity for energy savings. Replacement of working induction motors with more efficient ones can be an important resource for energy savings. A calculation of energy savings and payback periods, as a result of such a replacement, based on nameplate motor efficiency or manufacture-s data can lead to large errors [1]. Efficiency of induction motors (IMs) can be extracted using some procedures that use the no-load test results. In the cases that we must estimate the efficiency on-line, some of these procedures can-t be efficient. In some cases the efficiency estimates using the rating values of the motor, but these procedures can have errors due to the different working condition of the motor. In this paper the efficiency of an IM estimated by using the genetic algorithm. The results are compared with the measured values of the torque and power. The results show smaller errors for this procedure compared with the conventional classical procedures, hence the cost of the equipments is reduced and on-line estimation of the efficiency can be made.
Abstract: Increasing energy absorption is a significant parameter
in vehicle design. Absorbing more energy results in decreasing
occupant damage. Limitation of the deflection in a side impact results
in decreased energy absorption (SEA) and increased peak load (PL).
Hence a high crash force jeopardizes passenger safety and vehicle
integrity. The aims of this paper are to determine suitable dimensions
and material of a square beam subjected to side impact, in order to
maximize SEA and minimize PL. To achieve this novel goal, the
geometric parameters of a square beam are optimized using the
response surface method (RSM).multi-objective optimization is
performed, and the optimum design for different response features is
obtained.
Abstract: One of the long standing challenging aspect in mobile robotics is the ability to navigate autonomously, avoiding modeled and unmodeled obstacles especially in crowded and unpredictably changing environment. A successful way of structuring the navigation task in order to deal with the problem is within behavior based navigation approaches. In this study, Issues of individual behavior design and action coordination of the behaviors will be addressed using fuzzy logic. A layered approach is employed in this work in which a supervision layer based on the context makes a decision as to which behavior(s) to process (activate) rather than processing all behavior(s) and then blending the appropriate ones, as a result time and computational resources are saved.
Abstract: Future space vehicles will require the use of non-toxic, cryogenic propellants, because of the performance advantages over the toxic hypergolic propellants and also because of the environmental and handling concerns. A prototypical capillary flow liquid acquisition device (LAD) for cryogenic propellants was fabricated with a mesh screen, covering a rectangular flow channel with a cylindrical outlet tube, and was tested with liquid oxygen (LOX). In order to better understand the performance in various gravity environments and orientations with different submersion depths of the LAD, a series of computational fluid dynamics (CFD) simulations of LOX flow through the LAD screen channel, including horizontally and vertically submersions of the LAD channel assembly at normal gravity environment was conducted. Gravity effects on the flow field in LAD channel are inspected and analyzed through comparing the simulations.
Abstract: This paper reports the results of an experimental work
conducted to investigate the effect of curing conditions on the
compressive strength of self-compacting geopolymer concrete
prepared by using fly ash as base material and combination of sodium
hydroxide and sodium silicate as alkaline activator. The experiments
were conducted by varying the curing time and curing temperature in
the range of 24-96 hours and 60-90°C respectively. The essential
workability properties of freshly prepared Self-compacting
Geopolymer concrete such as filling ability, passing ability and
segregation resistance were evaluated by using Slump flow,
V-funnel, L-box and J-ring test methods. The fundamental
requirements of high flowability and resistance to segregation as
specified by guidelines on Self-compacting Concrete by EFNARC
were satisfied. Test results indicate that longer curing time and curing
the concrete specimens at higher temperatures result in higher
compressive strength. There was increase in compressive strength
with the increase in curing time; however increase in compressive
strength after 48 hours was not significant. Concrete specimens cured
at 70°C produced the highest compressive strength as compared to
specimens cured at 60°C, 80°C and 90°C.
Abstract: Not with standing the importance of foreign highly
skilled professionals for host economies, there is a paucity of
research studies investigating the role of the corporate social context
during the integration process. This research aims to address this
paucity by exploring the role of social capital in the integration of
foreign health professionals. It does so by using a qualitative research
approach. In this pilot study the hospital sector forms this study-s
sample and interviews were conducted with HR managers, foreign
health professionals and external HR consultants. It was found that
most of the participating hospitals had not established specific HR
practices and had only partly linked the development of
organisational social capital with a successful integration process.
This research contributes, for example, to the HR literature on the
integration of self-initiated expatriates by analysing the role of HRM
in generating organisational social capital needed for a successful
integration process.
Abstract: Fecal coliform bacteria are widely used as indicators of
sewage contamination in surface water. However, there are some
disadvantages in these microbial techniques including time consuming
(18-48h) and inability in discriminating between human and animal
fecal material sources. Therefore, it is necessary to seek a more
specific indicator of human sanitary waste. In this study, the feasibility
was investigated to apply caffeine and human pharmaceutical
compounds to identify the human-source contamination. The
correlation between caffeine and fecal coliform was also explored.
Surface water samples were collected from upstream, middle-stream
and downstream points respectively, along Rochor Canal, as well as 8
locations of Marina Bay. Results indicate that caffeine is a suitable
chemical tracer in Singapore because of its easy detection (in the range
of 0.30-2.0 ng/mL), compared with other chemicals monitored.
Relative low concentrations of human pharmaceutical compounds (<
0.07 ng/mL) in Rochor Canal and Marina Bay water samples make
them hard to be detected and difficult to be chemical tracer. However,
their existence can help to validate sewage contamination. In addition,
it was discovered the high correlation exists between caffeine
concentration and fecal coliform density in the Rochor Canal water
samples, demonstrating that caffeine is highly related to the
human-source contamination.
Abstract: Dual phase steels (DPS)s have a microstructure
consisting of a hard second phase called Martensite in the soft Ferrite
matrix. In recent years, there has been interest in dual-phase steels,
because the application of these materials has made significant usage;
particularly in the automotive sector Composite microstructure of
(DPS)s exhibit interesting characteristic mechanical properties such
as continuous yielding, low yield stress to tensile strength
ratios(YS/UTS), and relatively high formability; which offer
advantages compared with conventional high strength low alloy
steels(HSLAS). The research dealt with the characterization of
damage in (DPS)s. In this study by review the mechanisms of failure
due to volume fraction of martensite second phase; a new method is
introduced to identifying the mechanisms of failure in the various
phases of these types of steels. In this method the acoustic emission
(AE) technique was used to detect damage progression. These failure
mechanisms consist of Ferrite-Martensite interface decohesion and/or
martensite phase fracture. For this aim, dual phase steels with
different volume fraction of martensite second phase has provided by
various heat treatment methods on a low carbon steel (0.1% C), and
then AE monitoring is used during tensile test of these DPSs. From
AE measurements and an energy ratio curve elaborated from the
value of AE energy (it was obtained as the ratio between the strain
energy to the acoustic energy), that allows detecting important
events, corresponding to the sudden drops. These AE signals events
associated with various failure mechanisms are classified for ferrite
and (DPS)s with various amount of Vm and different martensite
morphology. It is found that AE energy increase with increasing Vm.
This increasing of AE energy is because of more contribution of
martensite fracture in the failure of samples with higher Vm. Final
results show a good relationship between the AE signals and the
mechanisms of failure.
Abstract: The hot deformation behavior of high strength low
alloy (HSLA) steels with different chemical compositions under hot
working conditions in the temperature range of 900 to 1100℃ and
strain rate range from 0.1 to 10 s-1 has been studied by performing a
series of hot compression tests. The dynamic materials model has been
employed for developing the processing maps, which show variation
of the efficiency of power dissipation with temperature and strain rate.
Also the Kumar-s model has been used for developing the instability
map, which shows variation of the instability for plastic deformation
with temperature and strain rate. The efficiency of power dissipation
increased with decreasing strain rate and increasing temperature in the
steel with higher Cr and Ti content. High efficiency of power
dissipation over 20 % was obtained at a finite strain level of 0.1 under
the conditions of strain rate lower than 1 s-1 and temperature higher
than 1050 ℃ . Plastic instability was expected in the regime of
temperatures lower than 1000 ℃ and strain rate lower than 0.3 s-1. Steel
with lower Cr and Ti contents showed high efficiency of power
dissipation at higher strain rate and lower temperature conditions.
Abstract: Injection forging is a Nett-shape manufacturing
process in which one or two punches move axially causing a radial
flow into a die cavity in a form which is prescribed by the exitgeometry,
such as pulley, flanges, gears and splines on a shaft. This
paper presents an experimental and numerical study of the injection
forging of splines in terms of load requirement and material flow.
Three dimensional finite element analyses are used to investigate the
effect of some important parameters in this process. The experiment
has been carried out using solid commercial lead billets with two
different billet diameters and four different dies.
Abstract: Fair share is one of the scheduling objectives supported on many production systems. However, fair share has been shown to cause performance problems for some users, especially the users with difficult jobs. This work is focusing on extending goaloriented parallel computer job scheduling policies to cover the fair share objective. Goal-oriented parallel computer job scheduling policies have been shown to achieve good scheduling performances when conflicting objectives are required. Goal-oriented policies achieve such good performance by using anytime combinatorial search techniques to find a good compromised schedule within a time limit. The experimental results show that the proposed goal-oriented parallel computer job scheduling policy (namely Tradeofffs( Tw:avgX)) achieves good scheduling performances and also provides good fair share performance.
Abstract: Road signs are the elements of roads with a lot of
influence in driver-s behavior. So that signals can fulfill its function,
they must overcome visibility and durability requirements,
particularly needed at night, when the coefficient of retroreflection
becomes a decisive factor in ensuring road safety. Accepting that the
visibility of the signage has implications for people-s safety, we
understand the importance to fulfill its function: to foster the highest
standards of service and safety in drivers. The usual conditions of
perception of any sign are determined by: age of the driver, reflective
material, luminosity, vehicle speed and emplacement. In this way,
this paper evaluates the different signals to increase the safety road.
Abstract: The purpose of this work is measurement of the
system presampling MTF of a variable resolution x-ray (VRX) CT
scanner. In this paper, we used the parameters of an actual VRX CT
scanner for simulation and study of effect of different focal spot sizes
on system presampling MTF by Monte Carlo method (GATE
simulation software). Focal spot size of 0.6 mm limited the spatial
resolution of the system to 5.5 cy/mm at incident angles of below 17º
for cell#1. By focal spot size of 0.3 mm the spatial resolution
increased up to 11 cy/mm and the limiting effect of focal spot size
appeared at incident angles of below 9º. The focal spot size of 0.3
mm could improve the spatial resolution to some extent but because
of magnification non-uniformity, there is a 10 cy/mm difference
between spatial resolution of cell#1 and cell#256. The focal spot size
of 0.1 mm acted as an ideal point source for this system. The spatial
resolution increased to more than 35 cy/mm and at all incident angles
the spatial resolution was a function of incident angle. By the way
focal spot size of 0.1 mm minimized the effect of magnification nonuniformity.