Abstract: Graphene material has found tremendous applications
in water desalination, DNA sequencing and energy storage. Multiple
nanopores are etched to create opening for water desalination and
energy storage applications. The nanopores created are of the order
of 3-5 nm allowing multiple ions to transport through the pore. In
this paper, we present for the first time, molecular dynamics study of
single ion transport, where only one ion passes through the graphene
nanopore. The diameter of the graphene nanopore is of the same
order as the hydration layers formed around each ion. Analogous to
single electron transport resulting from ionic transport is observed
for the first time. The current-voltage characteristics of such a device
are similar to single electron transport in quantum dots. The current
is blocked until a critical voltage, as the ions are trapped inside a
hydration shell. The trapped ions have a high energy barrier compared
to the applied input electrical voltage, preventing the ion to break free
from the hydration shell. This region is called “Coulomb blockade
region”. In this region, we observe zero transport of ions inside the
nanopore. However, when the electrical voltage is beyond the critical
voltage, the ion has sufficient energy to break free from the energy
barrier created by the hydration shell to enter into the pore. Thus, the
input voltage can control the transport of the ion inside the nanopore.
The device therefore acts as a binary storage unit, storing 0 when
no ion passes through the pore and storing 1 when a single ion
passes through the pore. We therefore postulate that the device can
be used for fluidic computing applications in chemistry and biology,
mimicking a computer. Furthermore, the trapped ion stores a finite
charge in the Coulomb blockade region; hence the device also acts
a super capacitor.
Abstract: This study investigates sorption of Cu and Zn contained in natural mine wastewater, using mixed mineral systems in sulfidic-anoxic condition. The mine wastewater was obtained from disused mine workings at Cwmheidol in Wales, United Kingdom. These contaminants flow into water courses. These water courses include River Rheidol. In this River fishing activities exist. In an attempt to reduce Cu-Zn levels of fish intake in the watercourses, single mineral systems and 1:1 mixed mineral systems of clay and goethite were tested with the mine waste water for copper and zinc removal at variable pH. Modelling of hydroxyl complexes was carried out using phreeqc method. Reactions using batch mode technique was conducted at room temperature. There was significant differences in the behaviour of copper and zinc removal using mixed mineral systems when compared to single mineral systems. All mixed mineral systems sorb more Cu than Zn when tested with mine wastewater.
Abstract: During the last decades, a number of food crises such
as Bovine Spongiform Encephalopathy (BSE), Mad-Cow disease,
Dioxin in chicken food, Food-and-Mouth Disease (FMD), have
certainly inflected the reliability of the food industry. Consequently,
the trend in applying different scientific methods of risk assessment
in food safety has obtained more attentions in the academic and
practice. However, lack of practical approach considering entire food
supply chain is tangible in the academic literature. In this regard, this
paper aims to apply risk assessment tool (FMEA) with integration of
Human Factor along the entire supply chain of food production and
test the method in a case study of Diary production, and analyze its
results.
Abstract: This paper presents the results of a study to assess
crucial aspects and the strength of the scientific basis of a typically
interdisciplinary, applied field: food supply chain risk assessment
research. Our approach is based on an advanced scientometrics
analysis that is a quantitative study of the disciplines of science based
on published literature to measure interdisciplinary. This paper aims
to describe the quantity and quality of the publication trends in food
supply chain risk assessment. The publication under study was
composed of 266 articles from database web of science. The results
were analyzed based on date of publication, type of document,
language of the documents, source of publications, subject areas,
authors and their affiliations, and the countries involved in
developing the articles.
Abstract: Food supply chain is one of the most complex supply
chain networks due to its perishable nature and customer oriented
products, and food safety is the major concern for this industry. IT
system could help to minimize the production and consumption of
unsafe food by controlling and monitoring the entire system.
However, there have been many issues in adoption of IT system in
this industry specifically within SMEs sector. With this regard, this
study presents a novel approach to use IT and tractability systems in
the food supply chain, using application of RFID and central
database.
Abstract: Contact stress is an important problem in industry.
This is a problem that in the first attention may be don-t appears, but
disregard of these stresses cause a lot of damages in machines. These
stresses occur at locations such as gear teeth, bearings, cams and
between a locomotive wheel and the railroad rail. These stresses
cause failure by excessive elastic deformation, yielding and fracture.
In this paper we intend show the effective parameters in contact
stress and ponder effect of curvature. In this paper we study contact
stresses on the surface of gear teeth and compare these stresses for
four popular profiles of gear teeth (involute, cycloid, epicycloids, and
hypocycloid). We study this problem with mathematical and finite
element methods and compare these two methods on different profile
surfaces.
Abstract: In order to evaluate the Effects of dual inoculation of
Azotobacter and Mycorrhiza with Nitrogen and Phosphorus levels on
yield and yield components of spring safflower, this study was
carried out in field of Farahan university in Markazi province in
2007. A factorial in a randomized complete block design with three
replications was used inoculation of Azotobacter (with inoculation
and without inoculation) and Mycorrhiza (with inoculation and
without inoculation ) with Nitrogen and Phosphorus levels [F0= N0+
P0 (kg.ha-1), F1= N50+ P25(kg.ha-1), F2= N100+ P50(kg.ha-1) and
F3= N150+ P75 (kg.ha-1)] on spring safflower (cultivar IL-111). In
this study characteristics such as: Harvest index, Hectolitre weight,
Root dry weight, Seed yield, Mycorrhizal Colonization Root,
Number of days to maturity were assessed. Results indicated that
treatment (A0M1F3) with grain yield (1556 kg.ha-1) and treatment
(A0M1F0) with grain yield (918 kg.ha-1) were significantly superior
to the other treatments and according to calculated, inoculation seeds
in plantig date with Azotobacter and Mycorrhiza to cause increase
grain yield about 5/38 percentage. we can by inoculation safflower
seeds with Azotobacter and Mycorrhiza too easily at the time sowing
date. The purpose of this research, study and evaluation the role of
biological fixation N and P, to provide for feeds plants.
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.
Abstract: Free Hemoglobin promotes the accumulation of
hydroxyl radicals by the heme iron, which can react with endogenous
hydrogen peroxide to produce free radicals which may cause severe
oxidative cell damage. Haptoglobin binds to Hemoglobin strongly
and Haptoglobin-Hemoglobin binding is irreversible. Peroxidase
activity of Haptoglobin(2-2)-Hemoglobin complex was assayed by
following increase of absorption of produced tetraguaiacol as the
second substrate of Haptoglobin-Hemoglobin complex at 470 nm and
42°C by UV-Vis spectrophotometer. The results have shown that
peroxidase activity of Haptoglobin(2-2)-Hemoglobin complex is
modulated via homotropic effect of hydrogen peroxide as allostric
substrate. On the other hand antioxidant property of Haptoglobin(2-
2)-Hemoglobin was increased via heterotropic effect of the two drugs
(especially ampicillin) on peroxidase activity of the complex. Both
drugs also have mild effect on quality of homotropic property of
peroxidase activity of Haptoglobin(2-2)-Hemoglobin complex.
Therefore, in vitro studies show that the two drugs may help Hp-Hb
complex to remove hydrogen peroxide from serum at pathologic
temperature ature (42 C).
Abstract: Data gathering is an essential operation in wireless
sensor network applications. So it requires energy efficiency
techniques to increase the lifetime of the network. Similarly,
clustering is also an effective technique to improve the energy
efficiency and network lifetime of wireless sensor networks. In this
paper, an energy efficient cluster formation protocol is proposed with
the objective of achieving low energy dissipation and latency without
sacrificing application specific quality. The objective is achieved by
applying randomized, adaptive, self-configuring cluster formation
and localized control for data transfers. It involves application -
specific data processing, such as data aggregation or compression.
The cluster formation algorithm allows each node to make
independent decisions, so as to generate good clusters as the end.
Simulation results show that the proposed protocol utilizes minimum
energy and latency for cluster formation, there by reducing the
overhead of the protocol.
Abstract: In this work, axisymetric CFD simulation of fixed bed
GTL reactor has been conducted, using computational fluid dynamics
(CFD). In fixed bed CFD modeling, when N (tube-to-particle
diameter ratio) has a large value, it is common to consider the packed
bed as a porous media. Synthesis gas (a mixture of predominantly
carbon monoxide and hydrogen) was fed to the reactor. The reactor
length was 20 cm, divided to three sections. The porous zone was in
the middle section of the reactor. The model equations were solved
employing finite volume method. The effects of particle diameter,
bed voidage, fluid velocity and bed length on pressure drop have
been investigated. Simulation results showed these parameters could
have remarkable impacts on the reactor pressure drop.
Abstract: Kwashiorkor is one of nutritional problem in
Indonesia, which lead to decrease immune system. This condition
causes susceptibility to infectious disease, especially tuberculosis.
Development of new tuberculosis vaccine will be an important
strategy to eliminate tuberculosis in kwashiorkor. Previous research
showed that 38-kDa Mycobacterium tuberculosis protein is one of the
potent immunogen. However, the role of oral immunization with 38-
kDa Mycobacterium tuberculosis protein to the number of
lymphocytes in the rat model of kwashiorkor is still unknown. We
used kwashiorkor rat model groups with 4% and 2% low protein diet.
Oral immunization with 38-kDa Mycobacterium tuberculosis protein
given with 2 booster every week. The lymphocytes number were
measured by flowcytometry. There was no significant difference
between the number of lymphocytes in the normal rat group and the
kwashiorkor rat groups. It may reveal the role of 38-kDa
Mycobacterium tuberculosis protein as a potent immunogen that can
increase the lymphocytes number from kwashiorkor rat model same
as normal rat.
Abstract: In the other to Study of drought stress and Selenium
spraying effect on superoxide dismotase (SOD) activity of rapeseed
(Brassica napus L.) cultivars in Shahr-e-Rey region, an experiment
carried out in Split factorial design in the basis of randomized
complete blocks with 4 replications in 2006. Irrigation in two levels:
Normal irrigation and irrigation with drought stress when the soil
electrical conductivity reached to 60 as main factor and rapeseed
cultivars in 3 levels Zarfam, Okapi, Opera and selenium spraying at
the beginning of flowering stage in 3 levels: 0, 16 and 21 g/ha as sub
factor.
The results showed that the simple and interaction effect of
irrigation, selenium and cultivars on SOD activity had significant
difference. In this case Zarfam cultivar with 2010 u.mg-1 protein and
Opera with 1454 u.mg-1 protein produced maximum and minimum
amounts of SOD activitiy. Interaction effect of irrigation and variety
showed that, normal irrigation in Opera with 1115 u.mg-1 protein
and drought stress in Zarfam with 2784 u.mg-1 protein conducted to
and minimum and maximum amounts of SOD activity.
Interaction effect of irrigation, cultivar and selenium on SOD
indicated that drought stress condition and 21 gr/ha selenium
spraying in Zarfam variety with 3146 u.mg-1 protein gained to
highest activities of SOD.
Abstract: Different numerical methods are employed and developed for simulating interfacial flows. A large range of applications belong to this group, e.g. two-phase flows of air bubbles in water or water drops in air. In such problems surface tension effects often play a dominant role. In this paper, various models of surface tension force for interfacial flows, the CSF, CSS, PCIL and SGIP models have been applied to simulate the motion of small air bubbles in water and the results were compared and reviewed. It has been pointed out that by using SGIP or PCIL models, we are able to simulate bubble rise and obtain results in close agreement with the experimental data.
Abstract: Nowadays, the earth is countered with serious problem
of air pollution. This problem has been started from the industrial
revolution and has been faster in recent years, so that leads the earth
to ecological and environmental disaster. One of its results is the
global warming problem and its related increase in global
temperature. The most important factors in air pollution especially in
urban environments are Automobiles and residential buildings that are
the biggest consumers of the fossil energies, so that if the residential
buildings as a big part of the consumers of such energies reduce their
consumption rate, the air pollution will be decreased. Since
Metropolises are the main centers of air pollution in the world,
assessment and analysis of efficient strategies in decreasing air
pollution in such cities, can lead to the desirable and suitable results
and can solve the problem at least in critical level. Tabriz city is one
of the most important metropolises in North west of Iran that about
two million people are living there. for its situation in cold dry
climate, has a high rate of fossil energies consumption that make air
pollution in its urban environment. These two factors, being both
metropolis and in cold dry climate, make this article try to analyze the
strategies of climatic design in old districts of the city and use them in
new districts of the future. These strategies can be used in this city
and other similar cities and pave the way to reduce energy
consumption and related air pollution to save whole world.
Abstract: In this paper, the two-dimensional stagger grid
interface pressure (SGIP) model has been generalized and presented
into three-dimensional form. For this purpose, various models of
surface tension force for interfacial flows have been investigated and
compared with each other. The VOF method has been used for
tracking the interface. To show the ability of the SGIP model for
three-dimensional flows in comparison with other models, pressure
contours, maximum spurious velocities, norm spurious flow
velocities and pressure jump error for motionless drop of liquid and
bubble of gas are calculated using different models. It has been
pointed out that SGIP model in comparison with the CSF, CSS and
PCIL models produces the least maximum and norm spurious
velocities. Additionally, the new model produces more accurate
results in calculating the pressure jumps across the interface for
motionless drop of liquid and bubble of gas which is generated in
surface tension force.
Abstract: In this paper, Lattice Boltzmann Method (LBM) is used to study laminar flow with mixed convection heat transfer inside a two-dimensional inclined lid-driven rectangular cavity with aspect ratio AR = 3. Bottom wall of the cavity is maintained at lower temperature than the top lid, and its vertical walls are assumed insulated. Top lid motion results in fluid motion inside the cavity. Inclination of the cavity causes horizontal and vertical components of velocity to be affected by buoyancy force. To include this effect, calculation procedure of macroscopic properties by LBM is changed and collision term of Boltzmann equation is modified. A computer program is developed to simulate this problem using BGK model of lattice Boltzmann method. The effects of the variations of Richardson number and inclination angle on the thermal and flow behavior of the fluid inside the cavity are investigated. The results are presented as velocity and temperature profiles, stream function contours and isotherms. It is concluded that LBM has good potential to simulate mixed convection heat transfer problems.
Abstract: Recently, several designs of single fed circularly
polarized microstrip antennas have been studied. Relatively, a few
designs for achieving circular polarization using triangular microstrip
antenna are available. Typically existing design of single fed
circularly polarized triangular microstrip antennas include the use of
equilateral triangular patch with a slit or a horizontal slot on the patch
or addition a narrow band stub on the edge or a vertex of triangular
patch.
In other word, with using a narrow band tune stub on middle of an
edge of triangle causes of facility to compensate the possible
fabrication error and substrate materials with easier adjusting the
tuner stub length. Even though disadvantages of this method is very
long of stub (approximate 1/3 length of triangle edge). In this paper,
instead of narrow band stub, a wide band stub has been applied,
therefore the length of stub by this method has been decreased
around 1/10 edge of triangle in addition changing the aperture angle
of stub, provides more facility for designing and producing circular
polarization wave.
Abstract: In this paper, a one-dimensional numerical approach is
used to study the effect of applying electrohydrodynamics on the
temperature and species mass fraction profiles along the microcombustor.
Premixed mixture is H2-Air with a multi-step chemistry
(9 species and 19 reactions). In the micro-scale combustion because
of the increasing ratio of area-to-volume, thermal and radical
quenching mechanisms are important. Also, there is a significant heat
loss from the combustor walls. By inserting a number of electrodes
into micro-combustor and applying high voltage to them corona
discharge occurs. This leads in moving of induced ions toward
natural molecules and colliding with them. So this phenomenon
causes the movement of the molecules and reattaches the flow to the
walls. It increases the velocity near the walls that reduces the wall
boundary layer. Consequently, applying electrohydrodynamics
mechanism can enhance the temperature profile in the microcombustor.
Ultimately, it prevents the flame quenching in microcombustor.
Abstract: Considering non-ideal behavior of fluids and its effects on hydrodynamic and mass transfer in multiphase flow is very essential. Simulations were performed that takes into account the effects of mass transfer and mixture non-ideality on hydrodynamics reported by Irani et al. In this paper, by assuming the density of phases to be constant and Raullt-s law instead of using EOS and fugacity coefficient definition, respectively for both the liquid and gas phases, the importance of non-ideality effects on mass transfer and hydrodynamic behavior was studied. The results for a system of octane/propane (T=323 K, P =445 kpa) also indicated that the assumption of constant density in simulation had major role to diverse from experimental data. Furthermore, comparison between obtained results and the previous report indicated significant differences between experimental data and simulation results with more ideal assumptions.