Abstract: Spent petroleum catalyst from Korean petrochemical
industry contains trace amount of metals such as Ni, V and Mo.
Therefore an attempt was made to recover those trace metal using
bioleaching process. Different leaching parameters such as Fe(II)
concentration, pulp density, pH, temperature and particle size of
spent catalyst particle were studied to evaluate their effects on the
leaching efficiency. All the three metal ions like Ni, V and Mo
followed dual kinetics, i.e., initial faster followed by slower rate. The
percentage of leaching efficiency of Ni and V were higher than Mo.
The leaching process followed a diffusion controlled model and the
product layer was observed to be impervious due to formation of
ammonium jarosite (NH4)Fe3(SO4)2(OH)6. In addition, the lower
leaching efficiency of Mo was observed due to a hydrophobic coating
of elemental sulfur over Mo matrix in the spent catalyst.
Abstract: Tread design has evolved over the years to achieve the common tread pattern used in current vehicles. However, to meet safety and comfort requirements, tread design considers more than one design factor. Tread design must consider the grip and drainage, and the manner in which to reduce rolling noise, which is one of the main factors considered by manufacturers. The main objective of this study was the application the computational fluid dynamics (CFD) technique to simulate the contact surface of the tire and ground. The results demonstrated an air-Pumping and large pressure drop effect in the process of contact surface. The results also revealed that the pressure can be used to analyze sound pressure level (SPL).
Abstract: Contamination of aromatic compounds in water can
cause severe long-lasting effects not only for biotic organism but also
on human health. Several alternative technologies for remediation of
polluted water have been attempted. One of these is adsorption
process of aromatic compounds by using organic modified clay
mineral. Porous structure of clay is potential properties for molecular
adsorptivity and it can be increased by immobilizing hydrophobic
structure to attract organic compounds. In this work natural
montmorillonite were modified with cetyltrimethylammonium
(CTMA+) and was evaluated for use as adsorbents of aromatic
compounds: benzene, toluene, and 2-chloro phenol in its single and
multicomponent solution by ethanol:water solvent. Preparation of
CTMA-montmorillonite was conducted by simple ion exchange
procedure and characterization was conducted by using x-day
diffraction (XRD), Fourier-transform infra red (FTIR) and gas
sorption analysis. The influence of structural modification of
montmorillonite on its adsorption capacity and adsorption affinity of
organic compound were studied. It was shown that adsorptivity of
montmorillonite was increased by modification associated with
arrangements of CTMA+ in the structure even the specific surface
area of modified montmorillonite was lower than raw
montmorillonite. Adsorption rate indicated that material has affinity
to adsorb compound by following order: benzene> toluene > 2-chloro
phenol. The adsorption isotherms of benzene and toluene showed 1st
order adsorption kinetic indicating a partition phenomenon of
compounds between the aqueous and organophilic CTMAmontmorillonite.
Abstract: Lipases are enzymes particularly amenable for
immobilization by entrapment methods, as they can work equally
well in aqueous or non-conventional media and long-time stability of
enzyme activity and enantioselectivity is needed to elaborate more
efficient bioprocesses. The improvement of Pseudomonas
fluorescens (Amano AK) lipase characteristics was investigated by
optimizing the immobilization procedure in hybrid organic-inorganic
matrices using ionic liquids as additives. Ionic liquids containing a
more hydrophobic alkyl group in the cationic moiety are beneficial
for the activity of immobilized lipase. Silanes with alkyl- or aryl
nonhydrolizable groups used as precursors in combination with
tetramethoxysilane could generate composites with higher
enantioselectivity compared to the native enzyme in acylation
reactions of secondary alcohols. The optimal effect on both activity
and enantioselectivity was achieved for the composite made from
octyltrimethoxysilane and tetramethoxysilane at 1:1 molar ratio (60%
increase of total activity following immobilization and enantiomeric
ratio of 30). Ionic liquids also demonstrated valuable properties as
reaction media for the studied reactions, comparable with the usual
organic solvent, hexane.
Abstract: The influence of viscosity on droplet diameter for
water-in-crude oil (w/o) emulsion with two different ratios; 20-80 %
and 50-50 % w/o emulsion was examined in the Brookfield
Rotational Digital Rheometer. The emulsion was prepared with
sorbitan sesquiolate (Span 83) act as emulsifier at varied temperature
and stirring speed in rotation per minute (rpm). Results showed that
the viscosity of w/o emulsion was strongly augmented by increasing
volume of water and decreased the temperature. The changing of
viscosity also altered the droplet size distribution. Changing of
droplet diameter was depends on the viscosity and the behavior of
emulsion either Newtonian or non-Newtonian.
Abstract: Due to the stringent legislation for emission of diesel
engines and also increasing demand on fuel consumption, the
importance of detailed 3D simulation of fuel injection, mixing and
combustion have been increased in the recent years. In the present
work, FIRE code has been used to study the detailed modeling of
spray and mixture formation in a Caterpillar heavy-duty diesel
engine. The paper provides an overview of the submodels
implemented, which account for liquid spray atomization, droplet
secondary break-up, droplet collision, impingement, turbulent
dispersion and evaporation. The simulation was performed from
intake valve closing (IVC) to exhaust valve opening (EVO). The
predicted in-cylinder pressure is validated by comparing with
existing experimental data. A good agreement between the predicted
and experimental values ensures the accuracy of the numerical
predictions collected with the present work. Predictions of engine
emissions were also performed and a good quantitative agreement
between measured and predicted NOx and soot emission data were
obtained with the use of the present Zeldowich mechanism and
Hiroyasu model. In addition, the results reported in this paper
illustrate that the numerical simulation can be one of the most
powerful and beneficial tools for the internal combustion engine
design, optimization and performance analysis.
Abstract: The Inter feeder Power Flow Regulator (IFPFR)
proposed in this paper consists of several voltage source inverters
with common dc bus; each inverter is connected in series with one of
different independent distribution feeders in the power system. This
paper is concerned with how to transfer power between the feeders for
load sharing purpose. The power controller of each inverter injects
the power (for sending feeder) or absorbs the power (for receiving
feeder) via injecting suitable voltage; this voltage injection is
simulated by voltage drop across series virtual impedance, the
impedance value is selected to achieve the concept of power exchange
between the feeders without perturbing the load voltage magnitude of
each feeder. In this paper a new control scheme for load sharing using
IFPFR is proposed.
Abstract: Aptamers are useful tools in microorganism
researches, diagnoses, and treatment. Aptamers are specific target
molecules formed by oligonucleic acid molecules, and are not
decomposed by alcohol. Aptamers used to detect Mycobacterium
tuberculosis (MTB) have been proved to have specific affinity to the
outer membrane proteins of MTB. This article presents a biosensor
chip set with aptamers for early detection of MTB with high specificity
and sensitivity, even in very low concentration. Meanwhile, we have
already made a modified hydrophobic facial mask module with
internal rendering hydrophobic for effectively collecting M.
tuberculosis.
Abstract: Current research has explored the impact of
instructional immediacy, defined as those behaviors that help build
close relationships or feelings of closeness, both on cognition and
motivation in the traditional classroom and online classroom;
however, online courses continue to suffer from higher dropout rates.
Based on Albert Bandura-s Social Cognitive Theory, four primary
relationships or interactions in an online course will be explored in
light of how they can provide immediacy thereby reducing student
attrition and improving cognitive learning. The four relationships are
teacher-student, student-student, and student-content, and studentcomputer.
Results of a study conducted with inservice teachers
completing a 14-week online professional development technology
course will be examined to demonstrate immediacy strategies that
improve cognitive learning and reduce student attrition. Results of
the study reveal that students can be motivated through various
interactions and instructional immediacy behaviors which lead to
higher completion rates, improved self-efficacy, and cognitive
learning.
Abstract: The effects of down slope steepness on soil splash distribution under a water drop impact have been investigated in this study. The equipment used are the burette to simulate a water drop, a splash cup filled with sandy soil which forms the source area and a splash board to collect the ejected particles. The results found in this study have shown that the apparent mass increased with increasing downslope angle following a linear regression equation with high coefficient of determination. In the same way, the radial soil splash distribution over the distance has been analyzed statistically, and an exponential function was the best fit of the relationship for the different slope angles. The curves and the regressions equations validate the well known FSDF and extend the theory of Van Dijk.
Abstract: The coalescer process is one of the methods for oily water treatment by increasing the oil droplet size in order to enhance the separating velocity and thus effective separation. However, the presence of surfactants in an oily emulsion can limit the obtained mechanisms due to the small oil size related with stabilized emulsion. In this regard, the purpose of this research is to improve the efficiency of the coalescer process for treating the stabilized emulsion. The effects of bed types, bed height, liquid flow rate and stage coalescer (step-bed) on the treatment efficiencies in term of COD values were studied. Note that the treatment efficiency obtained experimentally was estimated by using the COD values and oil droplet size distribution. The study has shown that the plastic media has more effective to attach with oil particles than the stainless one due to their hydrophobic properties. Furthermore, the suitable bed height (3.5 cm) and step bed (3.5 cm with 2 steps) were necessary in order to well obtain the coalescer performance. The application of step bed coalescer process in reactor has provided the higher treatment efficiencies in term of COD removal than those obtained with classical process. The proposed model for predicting the area under curve and thus treatment efficiency, based on the single collector efficiency (ηT) and the attachment efficiency (α), provides relatively a good coincidence between the experimental and predicted values of treatment efficiencies in this study.
Abstract: In this study we investigate the insertion of
pioglitazone, a Thiazolidinedione, into the two different sizes of
Carbon nanotub. It was shown that the insertion of pioglitazone into
the carbon nanotube in a water solute environment could be related
to the diameter of the nanotube and in the flow of the waters via
hydrophilic interactions. This encapsulated drug-carbon nanotube
molecule can be further applicable in other investigations in target
therapy with these agents regarding to reduce their potential toxic
effects.
Abstract: We demonstrate a 1×4 coarse wavelength
division-multiplexing (CWDM) planar concave grating
multiplexer/demultiplexer and its application in re-configurable
optical add/drop multiplexer (ROADM) system in silicon-on-insulator
substrate. The wavelengths of the demonstrated concave grating
multiplexer align well with the ITU-T standard. We demonstrate a
prototype of ROADM comprising two such concave gratings and four
wide-band thermo-optical MZI switches. Undercut technology which
removes the underneath silicon substrate is adopted in optical switches
in order to minimize the operation power. For all the thermal heaters,
the operation voltage is smaller than 1.5 V, and the switch power is
~2.4 mW. High throughput pseudorandom binary sequence (PRBS)
data transmission with up to 100 Gb/s is demonstrated, showing the
high-performance ROADM functionality.
Abstract: Reciprocating compressors are flexible to handle wide capacity and condition swings, offer a very efficient method of compressing almost any gas mixture in wide range of pressure, can generate high head independent of density, and have numerous applications and wide power ratings. These make them vital component in various units of industrial plants. In this paper optimum reciprocating compressor configuration regarding interstage pressures, low suction pressure, non-lubricated cylinder, speed of machine, capacity control system, compressor valve, lubrication system, piston rod coating, cylinder liner material, barring device, pressure drops, rod load, pin reversal, discharge temperature, cylinder coolant system, performance, flow, coupling, special tools, condition monitoring (including vibration, thermal and rod drop monitoring), commercial points, delivery and acoustic conditions are presented.
Abstract: Extensive use of the Internet coupled with the
marvelous growth in e-commerce and m-commerce has created a
huge demand for information security. The Secure Socket Layer
(SSL) protocol is the most widely used security protocol in the
Internet which meets this demand. It provides protection against
eaves droppings, tampering and forgery. The cryptographic
algorithms RC4 and HMAC have been in use for achieving security
services like confidentiality and authentication in the SSL. But recent
attacks against RC4 and HMAC have raised questions in the
confidence on these algorithms. Hence two novel cryptographic
algorithms MAJE4 and MACJER-320 have been proposed as
substitutes for them. The focus of this work is to demonstrate the
performance of these new algorithms and suggest them as dependable
alternatives to satisfy the need of security services in SSL. The
performance evaluation has been done by using practical
implementation method.
Abstract: This paper presents a unified approach based graph
theory and system theory postulates for the modeling and analysis
of Simple open cycle Gas turbine system. In the present paper, the
simple open cycle gas turbine system has been modeled up to its subsystem
level and system variables have been identified to develop the
process subgraphs. The theorems and algorithms of the graph theory
have been used to represent behavioural properties of the system like
rate of heat and work transfers rates, pressure drops and temperature
drops in the involved processes of the system. The processes have
been represented as edges of the process subgraphs and their limits
as the vertices of the process subgraphs. The system across variables
and through variables has been used to develop terminal equations of
the process subgraphs of the system. The set of equations developed
for vertices and edges of network graph are used to solve the system
for its process variables.
Abstract: The rheological properties, structure and potential synergistic interactions of whey proteins (1-6%) and inulin (20%) in mixed gels in the presence of CaCl2 was the aim of this study. Whey proteins have a strong influence on inulin gel formation. At low concentrations (2%) whey proteins did not impair in inulin gel formation. At higher concentration (4%) whey proteins impaired inulin gelation and inulin impaired the formation of a Ca2+-induced whey protein network. The presence of whey proteins at a level allowing for protein gel network formation (6%) significantly increased the rheological parameters values of the gels. SEM micrographs showed that whey protein structure was coated by inulin moieties which could make the mixed gels firmer. The protein surface hydrophobicity measurements did not exclude synergistic interactions between inulin and whey proteins, however. The use of an electrophoretic technique did not show any stable inulin-whey protein complexes.
Abstract: A wireless Ad-hoc network consists of wireless nodes
communicating without the need for a centralized administration, in
which all nodes potentially contribute to the routing process.In this
paper, we report the simulation results of four different scenarios for
wireless ad hoc networks having thirty nodes. The performances of
proposed networks are evaluated in terms of number of hops per
route, delay and throughput with the help of OPNET simulator.
Channel speed 1 Mbps and simulation time 600 sim-seconds were
taken for all scenarios. For the above analysis DSR routing protocols
has been used. The throughput obtained from the above analysis
(four scenario) are compared as shown in Figure 3. The average
media access delay at node_20 for two routes and at node_20 for four
different scenario are compared as shown in Figures 4 and 5. It is
observed that the throughput will degrade when it will follow
different hops for same source to destination (i.e. it has dropped from
1.55 Mbps to 1.43 Mbps which is around 9.7%, and then dropped to
0.48Mbps which is around 35%).