Abstract: Pt/γ-Al2O3 membrane catalysts were prepared via an
evaporative-crystallization deposition method. The obtained Pt/γ-
Al2O3 catalyst activity was tested after characterization (SEM-EDAX
observation, BET measurement, permeability assessment) in the
catalytic oxidation of selected volatile organic compound (VOC) i.e.
propane, fed in mixture of oxygen. The VOC conversion (nearly
90%) obtained by varying the operating temperature showed that
flow-through membrane reactor might do better in the abatement of
VOCs.
Abstract: An unconventional composite inorganic ceramic
membrane capable of enhancing carbon dioxide emission decline was
fabricated and tested at laboratory scale in conformism to various
environmental guidelines and also to mitigate the effect of global
warming. A review of the existing membrane technologies for carbon
capture including the relevant gas transport mechanisms is presented.
Single gas permeation experiments using silica modified ceramic
membrane with internal diameter 20mm, outside diameter 25mm and
length of 368mm deposited on a macro porous support was carried
out to investigate individual gas permeation behaviours at different
pressures at room temperature. Membrane fabrication was achieved
using after a dip coating method. Nitrogen, Carbon dioxide, Argon,
Oxygen and Methane pure gases were used to investigate their
individual permeation rates at various pressures. Results show that
the gas flow rate increases with pressure drop. However above a
pressure of 3bar, CO2 permeability ratio to that of the other gases
indicated control of a more selective surface adsorptive transport
mechanism.
Abstract: Polymer Electrolyte Membrane Fuel Cell (PEMFC) is
such a time-vary nonlinear dynamic system. The traditional linear
modeling approach is hard to estimate structure correctly of PEMFC
system. From this reason, this paper presents a nonlinear modeling of
the PEMFC using Neural Network Auto-regressive model with
eXogenous inputs (NNARX) approach. The multilayer perception
(MLP) network is applied to evaluate the structure of the NNARX
model of PEMFC. The validity and accuracy of NNARX model are
tested by one step ahead relating output voltage to input current from
measured experimental of PEMFC. The results show that the obtained
nonlinear NNARX model can efficiently approximate the dynamic
mode of the PEMFC and model output and system measured output
consistently.
Abstract: In the present work, Electrochemical Impedance
Spectrocopy (EIS) is applied to study the transport of different metal
cations through a cation-exchange membrane. This technique enables
the identification of the ionic-transport characteristics and to
distinguish between different transport mechanisms occurring at
different current density ranges. The impedance spectra are
dependent on the applied dc current density, on the type of cation and
on the concentration.
When the applied dc current density increases, the diameter of the
impedance spectra loops increases because all the components of
membrane system resistance increase. The diameter of the impedance
plots decreases in the order of Na(I), Ni(II) and Cr(III) due to the
increased interactions between the negatively charged sulfonic
groups of the membrane and the cations with greater charge. Nyquist
plots are shifted towards lower values of the real impedance, and its
diameter decreases with the increase of concentration due to the
decrease of the solution resistance.
Abstract: Forward Osmosis (FO) polyamide thin-film composite
membranes have been prepared by interfacial polymerization using
commercial UF polyethersulfoneas membrane support. Different
interfacial polymerization times (10s, 30s and 60s) in the organic
solution containing trimesoyl chloride (TMC) at constant m-phenylenediamine
(MPD) concentration (2% w/v) were studied. The
synthesized polyamide membranes then tested for treatment of
natural organic matter (NOM) and compared to commercial Cellulose
TriAcetate (CTA) membrane. It was found that membrane prepared
with higher reaction time (30s and 60s) exhibited better membrane
performance (flux and humic acid removal) over commercial CTA
membrane.
Abstract: For centuries humans have used the antimicrobial
properties of copper to their advantage. Yet, after all these years the
underlying mechanisms of copper mediated cell death in various
microbes remain unclear. We had explored the hypothesis that copper
mediated increased levels of lipid peroxidation in the membrane fatty
acids is responsible for increased killing in Escherichia coli. In this
study we show that in both gram positive (Staphylococcus aureus)
and gram negative (Pseudomonas aeruginosa) bacteria there is a
strong correlation between copper mediated cell death and increased
levels of lipid peroxidation. Interestingly, the non-spore forming
gram positive bacteria as well as gram negative bacteria show similar
patterns of cell death, increased levels of lipid peroxidation, as well
as genomic DNA degradation, however there is some difference in
loss in membrane integrity upon exposure to copper alloy surface.
Abstract: Newly synthesized Polypropylene-g-Polyethylene
glycol polymer was first time used for a compartment-less enzymatic
fuel cell. Working electrodes based on Polypropylene-g-Polyethylene
glycol were operated as unmediated and mediated system (with
ferrocene and gold/cobalt oxide nanoparticles). Glucose oxidase and
bilirubin oxidase was selected as anodic and cathodic enzyme,
respectively. Glucose was used as fuel in a single-compartment and
membrane-less cell. Maximum power density was obtained as 0.65
nW cm-2, 65 nW cm-2 and 23500 nW cm-2 from the unmediated,
ferrocene and gold/cobalt oxide modified polymeric film,
respectively. Power density was calculated to be ~16000 nW cm-2 for
undiluted wastewater sample with gold/cobalt oxide nanoparticles
including system.
Abstract: In order to study the aerodynamic performance of a
semi-flexible membrane wing, Fluid-Structure Interaction simulations
have been performed. The fluid problem has been modeled using
two different approaches which are the vortex panel method and the
numerical solution of the Navier-Stokes equations. Nonlinear analysis
of the structural problem is performed using the Finite Element
Method. Comparison between the two fluid solvers has been made.
Aerodynamic performance of the wing is discussed regarding its
lift and drag coefficients and they are compared with those of the
equivalent rigid wing.
Abstract: Cell volume, together with membrane potential and
intracellular hydrogen ion concentration, is an essential biophysical
parameter for normal cellular activity. Cell volumes can be altered by
osmotically active compounds and extracellular tonicity.
In this study, a simple mathematical model of osmotically induced
cell swelling and shrinking is presented. Emphasis is given to water
diffusion across the membrane. The mathematical description of the
cellular behavior consists in a system of coupled ordinary differential
equations. We compare experimental data of cell volume alterations
driven by differences in osmotic pressure with mathematical
simulations under hypotonic and hypertonic conditions. Implications
for a future model are also discussed.
Abstract: Polysulfone (PSU) is a specialty engineering polymer
having various industrial applications. PSU is especially used in
waste water treatment membranes due to its good mechanical
properties, structural and chemical stability. But it is a hydrophobic
material and therefore its surface aim to pollute easily. In order to
resolve this problem and extend the properties of membrane, PSU
surface is rendered hydrophilic by addition of the sepiolite
nanofibers. Sepiolite is one of the natural clays, which is a hydrate
magnesium silicate fiber, also one of the well known layered clays of
the montmorillonites where has several unique channels and pores
within. It has also moisture durability, strength and low price.
Sepiolite channels give great capacity of absorption and good surface
properties. In this study, nanocomposites of commercial PSU and
Sepiolite were prepared by solvent mixing method. Different organic
solvents and their mixtures were used. Rheological characteristics of
PSU-Sepiolite solvent mixtures were analyzed, the solubility of
nanocomposite content in those mixtures were studied.
Abstract: Liver disorders are one of the major problems of the
world. Despite its frequent occurrence, high morbidity and high
mortality, its medical management is currently inadequate. This study
was designed to evaluate the hepatoprotective effect of saponin
extract of the root of Garcinia kola on the integrity of the liver of
paracetamol induced wistar albino rats. Twenty five (25) male adult
wistar albino rats were divided into five (5) groups. Group I was the
Control group that received distilled water only, group II was the
negative control that received 2 g/kg of paracetamol on the 13th day,
and group III, IV and V were pre-treated with 100, 200 and
400mg/kg of the saponin extract before inducing the liver damage on
the 13th day with 2 g/kg of paracetamol. Twenty four (24) h after
administration, the rats were sacrificed and blood samples were
collected. The serum Alanine Transaminase (ALT), Aspartate
Transaminase (AST), Alkaline Phosphatase (ALP) activities,
Bilirubin and conjugated bilirubin, glucose and protein
concentrations were evaluated. The liver was fixed immediately in
Formalin and was processed and stained in Haematoxylin and Eosin
(H&E). Administration of saponin extract from the root of Garcinia
kola significantly decreased paracetamol induced elevated enzymes
in the test group. Also histological observations showed that saponin
extract of the root of Garcinia kola exhibited a significant liver
protection against the toxicant as evident by the cells trying to return
to normal. Saponin extract from the root of Garcinia kola indicated a
protection of structural integrity of the hepatocytic cell membrane
and regeneration of the damaged liver.
Abstract: The purpose of this paper is to examine gas transport
behavior of mixed matrix membranes (MMMs) combined with
porous particles. Main existing models are categorized in two main
groups; two-phase (ideal contact) and three-phase (non-ideal contact).
A new coefficient, J, was obtained to express equations for estimating
effect of the particle porosity in two-phase and three-phase models.
Modified models evaluates with existing models and experimental
data using Matlab software. Comparison of gas permeability of
proposed modified models with existing models in different MMMs
shows a better prediction of gas permeability in MMMs.
Abstract: Background: Bleeding during first half of pregnancy
mostly originates from placenta, some abort, others are at risk of
complications. Objective: Study was done to know perinatal outcome
with bleeding up to 20 weeks in singleton pregnancy. Material
Methods: Subjects were 1020, equal controls managed over 2 years,
435 had viable pregnancy at admission, 135 excluded, 300 followed
for perinatal outcome, 99 (19.52% up to 10 weeks), 201 (39.18% of
11-20 weeks). Results: Hypertensive disorders occurred in 24% cases
of bleeding within 10 weeks, 22% 11-20 weeks 14.79% controls,
placenta previa 4% in 10 weeks, 0.9% 11-20 weeks, 0.97% controls,
prelabor rupture of membranes in 16%, 7.45% controls. 20% up to 10
weeks, 35% 11-20 weeks, 18% controls had fetal growth restriction,
34.34% up to 10 weeks 30.35% of 11-20 weeks 17.17% controls had
preterm births, perinatal mortality rate in study was 118.62, in
controls 68.16 (Uneventful pregnancy in 13.52% study, 46.11%
controls). Conclusion: Once bleeding occurs, one third continue
pregnancy, maternal neonatal outcome gets affected with variations
in cases of bleeding within first 10 weeks & 11-20 weeks.
Abstract: Since the marine environmental conditions are
extremely different from the other ones, marine actinomycetes might
produce novel bioactive compounds. Therefore, actinomycete strains
were screened from marine water and sediment samples collected
from the coastal areas of Northern Vietnam. Ninety-nine
actinomycete strains were obtained on starch-casein agar media by
dilution technique, only seven strains, named HP112, HP12, HP411,
HPN11, HP 11, HPT13 and HPX12, showed significant antibacterial
activity against both gram-positive and gram-negative bacteria
(Bacillus subtilis ATCC 6633, Staphylococcus epidemidis ATCC
12228, Escherichia coli ATCC 11105). Further studies were carried
out with the most active HP411 strain against Candida albicans
ATCC 10231. This strain could grow rapidly on starch casein agar
and other media with high salt containing 7-10% NaCl at 28-30oC.
Spore-chain of HP411 showed an elongated and circular shape with
10 to 30 spores/chain. Identification of the strain was carried out by
employing the taxonomical studies including the 16S rRNA
sequence. Based on phylogenetic and phenotypic evidence it is
proposed that HP411 to be belongs to species Streptomyces
variabilis. The potent of the crude extract of fermentation broth of
HP411 that are effective against wide range of pathogens: both grampositive,
gram-negative and fungi. Further studies revealed that the
crude extract HP411 could obtain the anticancer activity for cancer
cell lines: Hep-G2 (liver cancer cell line); RD (cardiac and skeletal
muscle letters cell line); FL (membrane of the uterus cancer cell line).
However, the actinomycetes from marine ecosystem will be useful
for the discovery of new drugs in the future.
Abstract: GRF, Growth regulating factor, genes encode a novel
class of plant-specific transcription factors. The GRF proteins play a
role in the regulation of cell numbers in young and growing tissues
and may act as transcription activations in growth and development
of plants. Identification of GRF genes and their expression are
important in plants to performance of the growth and development of
various organs. In this study, to better understanding the structural
and functional differences of GRFs family, 45 GRF proteins
sequences in A. thaliana, Z. mays, O. sativa, B. napus, B. rapa, H.
vulgare and S. bicolor, have been collected and analyzed through
bioinformatics data mining. As a result, in secondary structure of
GRFs, the number of alpha helices was more than beta sheets and in
all of them QLQ domains were completely in the biggest alpha helix.
In all GRFs, QLQ and WRC domains were completely protected
except in AtGRF9. These proteins have no trans-membrane domain
and due to have nuclear localization signals act in nuclear and they
are component of unstable proteins in the test tube.
Abstract: This paper presents a new method to design nonlinear
feedback linearization controller for PEMFCs (Polymer Electrolyte
Membrane Fuel Cells). A nonlinear controller is designed based on
nonlinear model to prolong the stack life of PEMFCs. Since it is
known that large deviations between hydrogen and oxygen partial
pressures can cause severe membrane damage in the fuel cell,
feedback linearization is applied to the PEMFC system so that the
deviation can be kept as small as possible during disturbances or load
variations. To obtain an accurate feedback linearization controller,
tuning the linear parameters are always important. So in proposed
study NSGA (Non-Dominated Sorting Genetic Algorithm)-II method
was used to tune the designed controller in aim to decrease the
controller tracking error. The simulation result showed that the
proposed method tuned the controller efficiently.
Abstract: Persea declinata (Bl.) Kosterm is a member of the
Lauraceae family, widely distributed in Southeast Asia. It is from the
same genus with avocado (Persea americana Mill), which is widely
consumed as food and for medicinal purposes. In the present study,
we examined the anticancer properties of Persea declinata (Bl.)
Kosterm bark methanolic crude extract (PDM). PDM exhibited a
potent antiproliferative effect in MCF-7 human breast cancer cells,
with an IC50 value of 16.68 .g/mL after 48h of treatment. We
observed that PDM caused cell cycle arrest and subsequent apoptosis
in MCF-7 cells, as exhibited by increased population at G0/G1 phase,
higher lactate dehydrogenase (LDH) release, and DNA
fragmentation. Mechanistic studies showed that PDM caused
significant elevation in ROS production, leading to perturbation of
mitochondrial membrane potential, cell permeability, and activation
of caspases-3/7. On the other hand, real-time PCR and Western blot
analysis showed that PDM treatment increased the expression of the
proapoptotic molecule, Bax, but decreased the expression of
prosurvival proteins, Bcl-2 and Bcl-xL, in a dose-dependent manner.
These findings imply that PDM could inhibit proliferation in MCF-7
cells via cell cycle arrest and apoptosis induction, indicating its
potential as a therapeutic agent worthy of further development.
Abstract: Natural antimicrobials are used to preserve foods that
can be found in plants, animals, and microorganisms. Antimicrobial
substances are natural or artificial agents that produced by
microorganisms or obtained semi/total chemical synthesis are used at
low concentrations to inhibit the growth of other microorganisms.
Food borne pathogens and spoilage microorganisms are inactivated
by the use of antagonistic microorganisms and their metabolites.
Yeasts can produce toxic proteins or glycoproteins (toxins) that cause
inhibition of sensitive bacteria and yeast species. Antimicrobial
substance producing phenotypes belonging different yeast genus
were isolated from different sources. Toxins secreted by many yeast
strains inhibiting the growth of other yeast strains. These strains show
antimicrobial activity, inhibiting the growth of mold and bacteria.
The effect of antimicrobial agents produced by yeasts can be
extremely fast, and therefore may be used in various treatment
procedures. Rapid inhibition of microorganisms is possibly caused by
microbial cell membrane lipopolysaccharide binding and in
activation (neutralization) effect. Antimicrobial agents inhibit the
target cells via different mechanisms of action.
Abstract: A polypropylene hollow fiber membrane module is used for separating dissolved gases which contain dissolved oxygen from water. These dissolved gases can be used for underwater breathing. To be used for a human, the minimum amount of oxygen is essential. To increase separation of dissolved gases, much water and high surface area of hollow fibers are requested. For efficient separation system, performance of single membrane module with high surface area needs to be investigated.
In this study, we set up experimental devices for analyzing separation characteristics of dissolved gases including oxygen from water using a polypropylene hollow fiber membrane module. Separation of dissolved gases from water is investigated with variations of water flow rates. Composition of dissolved gases is also measured using GC. These results expect to be used in developing the portable separation system.
Abstract: This research presents the design, fabrication and application of a flavor sensor for an integrated electronic tongue and electronic nose that can allow rapid characterization of multi-component mixtures in a solution. The odor gas and liquid are separated using hydrophobic porous membrane in micro fluidic channel. The sensor uses an array composed of microbeads in micromachined cavities localized on silicon wafer. Sensing occurs via colorimetric and fluorescence changes to receptors and indicator molecules that are attached to termination sites on the polymeric microbeads. As a result, the sensor array system enables simultaneous and near-real-time analyses using small samples and reagent volumes with the capacity to incorporate significant redundancies. One of the key parts of the system is a passive pump driven only by capillary force. The hydrophilic surface of the fluidic structure draws the sample into the sensor array without any moving mechanical parts. Since there is no moving mechanical component in the structure, the size of the fluidic structure can be compact and the fabrication becomes simple when compared to the device including active microfluidic components. These factors should make the proposed system inexpensive to mass-produce, portable and compatible with biomedical applications.