Abstract: Levan, an exopolysaccharide, was produced by
Microbacterium laevaniformans and its yield was characterized as a
function of concentrations of date syrup, sucrose and the fermentation
time. The optimum condition for levan production from sucrose was
at concentration of 20% sucrose for 48 h and for date syrup was 25%
for 48 h. The results show that an increase in fermentation time
caused a decrease in the levan production at all concentrations of date
syrup tested. Under these conditions after 48 h in sucrose medium,
levan production reached 48.9 g/L and for date syrup reached 10.48
g/L . The effect of pH on the yield of the purified levan was examined
and the optimum pH for levan production was determined to be 6.0.
Levan was composed mainly of fructose residues when analyzed by
TLC and FT-IR spectroscopy. Date syrup is a cheap substrate widely
available in Iran and has potential for levan production. The thermal
stability of levan was assessed by Thermo Gravimetric Analysis
(TGA) that revealed the onset of decomposition near to 49°C for the
levan produced from sucrose and 51°C for the levan from date syrup.
DSC results showed a single Tg at 98°C for levan produced from
sucrose and 206 °C for levan from date syrup.
Abstract: Sedimentation is a hydraulic phenomenon that is
emerging as a serious challenge in river engineering. When the flow
reaches a certain state that gather potential energy, it shifts the
sediment load along channel bed. The transport of such materials can
be in the form of suspended and bed loads. The movement of these
along the river course and channels and the ways in which this could
influence the water intakes is considered as the major challenges for
sustainable O&M of hydraulic structures. This could be very serious
in arid and semi-arid regions like Iran, where inappropriate watershed
management could lead to shifting a great deal of sediments into the
reservoirs and irrigation systems. This paper aims to investigate
sedimentation in the Western Canal of Dez Diversion Weir in Iran,
identifying factors which influence the process and provide ways in
which to mitigate its detrimental effects by using the SHARC
Software.
For the purpose of this paper, data from the Dezful water authority
and Dezful Hydrometric Station pertinent to a river course of about 6
Km were used.
Results estimated sand and silt bed loads concentrations to be 193
ppm and 827ppm respectively. Given the available data on average
annual bed loads and average suspended sediment loads of 165ppm
and 837ppm, there was a significant statistical difference (16%)
between the sand grains, whereas no significant difference (1.2%)
was find in the silt grain sizes. One explanation for such finding
being that along the 6 Km river course there was considerable
meandering effects which explains recent shift in the hydraulic
behavior along the stream course under investigation. The sand
concentration in downstream relative to present state of the canal
showed a steep descending curve. Sediment trapping on the other
hand indicated a steep ascending curve. These occurred because the
diversion weir was not considered in the simulation model.
Abstract: For stricter drinking water regulations in the future, reducing the humic acid and disinfection byproducts in raw water, namely, trihalomethanes (THMs) and haloacetic acids (HAAs) is worthy for research. To investigate the removal of waterborne organic material using a lab-scale of bio-activated carbon filter under different EBCT, the concentrations of humic acid prepared were 0.01, 0.03, 0.06, 0.12, 0.17, 0.23, and 0.29 mg/L. Then we conducted experiments using a pilot plant with in-field of the serially connected bio-activated carbon filters and hollow fiber membrane processes employed in traditional water purification plants. Results showed under low TOC conditions of humic acid in influent (0.69 to 1.03 mg TOC/L) with an EBCT of 30 min, 40 min, and 50 min, TOC removal rates increases with greater EBCT, attaining about 39 % removal rate. The removal rate of THMs and HAAs by BACF was 54.8 % and 89.0 %, respectively.
Abstract: This study has applied the L16 orthogonal array of the
Taguchi method to determine the optimized polymeric
Nanocomposite asphalt binder. Three control factors are defined as
polypropylene plastomer (PP), styrene-butadiene-styrene elastomer
(SBS) and Nanoclay. Four level of concentration contents are
introduced for prepared asphalt binder samples. all samples were
prepared with 4.5% of bitumen 60/70 content. Compressive strength
tests were carried out for defining the optimized sample via
QUALITEK-4 software. SBS with 3%, PP with 5 % and Nanoclay
with 1.5% of concentrations are defined as the optimized
Nanocomposite asphalt binders. The confirmation compressive
strength and also softening point tests showed that modification of
asphalt binders with this method, improved the compressive strength
and softening points of asphalt binders up to 55%.
Abstract: The direct discharge of palm oil mill effluent (POME) wastewater causes serious environmental pollution due to its high chemical oxygen demand (COD) and biochemical oxygen demand (BOD). Traditional ways for POME treatment have both economical and environmental disadvantages. In this study, a membrane anaerobic system (MAS) was used as an alternative, cost effective method for treating POME. Six steady states were attained as a part of a kinetic study that considered concentration ranges of 8,220 to 15,400 mg/l for mixed liquor suspended solids (MLSS) and 6,329 to 13,244 mg/l for mixed liquor volatile suspended solids (MLVSS). Kinetic equations from Monod, Contois and Chen & Hashimoto were employed to describe the kinetics of POME treatment at organic loading rates ranging from 2 to 13 kg COD/m3/d. throughout the experiment, the removal efficiency of COD was from 94.8 to 96.5% with hydraulic retention time, HRT from 400.6 to 5.7 days. The growth yield coefficient, Y was found to be 0.62gVSS/g COD the specific microorganism decay rate was 0.21 d-1 and the methane gas yield production rate was between 0.25 l/g COD/d and 0.58 l/g COD/d. Steady state influent COD concentrations increased from 18,302 mg/l in the first steady state to 43,500 mg/l in the sixth steady state. The minimum solids retention time, which was obtained from the three kinetic models ranged from 5 to 12.3 days. The k values were in the range of 0.35 – 0.519 g COD/ g VSS • d and values were between 0.26 and 0.379 d-1. The solids retention time (SRT) decreased from 800 days to 11.6 days. The complete treatment reduced the COD content to 2279 mg/l equivalent to a reduction of 94.8% reduction from the original.
Abstract: Biological treatment of secondary effluent wastewater
by two combined denitrification/oxic filtration systems packed with
Lock type(denitrification filter) and ceramic ball (oxic filter) has been
studied for 5months. Two phases of operating conditions were carried
out with an influent nitrate and ammonia concentrations varied from
5.8 to 11.7mg/L and 5.4 to 12.4mg/L,respectively.
Denitrification/oxic filter treatment system were operated under an
EBCT (Empty Bed Contact Time) of 4h at system recirculation ratio in
the range from 0 to 300% (Linear Velocity increased 19.5m/d to
78m/d). The system efficiency of denitrification , nitrification over
95% respectively. Total nitrogen and COD removal range from
54.6%(recirculation 0%) to 92.3%(recirculation 300%) and 10% to
62.5%, respectively.
Abstract: Removal of PCP by a system combining
biodegradation by biofilm and adsorption was investigated here.
Three studies were conducted employing batch tests, sequencing
batch reactor (SBR) and continuous biofilm activated carbon
column reactor (BACCOR). The combination of biofilm-GAC
batch process removed about 30% more PCP than GAC adsorption
alone. For the SBR processes, both the suspended and attached
biomass could remove more than 90% of the PCP after
acclimatisation. BACCOR was able to remove more than 98% of
PCP-Na at concentrations ranging from 10 to 100 mg/L, at empty
bed contact time (EBCT) ranging from 0.75 to 4 hours. Pure and
mixed cultures from BACCOR were tested for use of PCP as sole
carbon and energy source under aerobic conditions. The isolates
were able to degrade up to 42% of PCP under aerobic conditions in
pure cultures. However, mixed cultures were found able to degrade
more than 99% PCP indicating interdependence of species.
Abstract: Salinity level may affect early development of
biofuel feedstock crops. The biofuel feedstock crops canola
(Brassica napus L.), sorghum [Sorghum bicolor (L.) Moench], and
sunflower (Helianthus annuus L.); and the potential feedstock crop
sweet corn (Zea mays L.) were planted in media in pots and treated
with aqueous solutions of 0, 0.1, 0.5 and 1.0 M NaCl once at: 1)
planting; 2) 7-10 days after planting or 3) first true leaf expansion.
An additional treatment (4) comprised of one-half strength of the 0.1,
0.5 and 1.0 M (concentrations 0.05, 0.25, 0.5 M at each application)
was applied at first true leaf expansion and four days later. Survival
of most crops decreased below 90% above 0.5 M; survival of canola
decreased above 0.1 M. Application timing had little effect on crop
survival. For canola root fresh and dry weights improved when
application was at plant emergence; for sorghum top and root fresh
weights improved when the split application was used. When
application was at planting root dry weight was improved over most
other applications. Sunflower top fresh weight was among the
highest when saline solutions were split and top dry weight was
among the highest when application was at plant emergence. Sweet
corn root fresh weight was improved when the split application was
used or application was at planting. Sweet corn root dry weight was
highest when application was at planting or plant emergence. Even at
high salinity rates survival rates greater than what might be expected
occurred. Plants that survived appear to be able to adjust to saline
during the early stages of development.
Abstract: Simultaneous recovery of copper and DCA from
simulated MEUF concentrated stream was investigated. Effects of
surfactant (DCA) and metal (copper) concentrations, surfactant to
metal molar ratio (S/M ratio), electroplating voltage, EDTA
concentration, solution pH, and salt concentration on metal recovery
and current efficiency were studied. Electric voltage of -0.5 V was
shown to be optimum operation condition in terms of Cu recovery,
current efficiency, and surfactant recovery. Increasing Cu recovery and
current efficiency were observed with increases of Cu concentration
while keeping concentration of DCA constant. However, increasing
both Cu and DCA concentration while keeping S/M ratio constant at
2.5 showed detrimental effect on Cu recovery at DCA concentration
higher than 15 mM. Cu recovery decreases with increasing pH while
current efficiency showed an opposite trend. It is believed that
conductivity is the main cause for discrepancy of Cu recovery and
current efficiency observed at different pH. Finally, it was shown that
EDTA had adverse effect on both Cu recovery and current efficiency
while addition of NaCl salt had negative impact on current efficiency
at concentration higher than 8000 mg/L.
Abstract: In this paper we have proposed a methodology to
develop an amperometric biosensor for the analysis of glucose
concentration using a simple microcontroller based data acquisition
system. The work involves the development of Detachable
Membrane Unit (enzyme based biomembrane) with immobilized
glucose oxidase on the membrane and interfacing the same to the
signal conditioning system. The current generated by the biosensor
for different glucose concentrations was signal conditioned, then
acquired and computed by a simple AT89C51-microcontroller. The
optimum operating parameters for the better performance were found
and reported. The detailed performance evaluation of the biosensor
has been carried out. The proposed microcontroller based biosensor
system has the sensitivity of 0.04V/g/dl, with a resolution of
50mg/dl. It has exhibited very good inter day stability observed up to
30 days. Comparing to the reference method such as HPLC, the
accuracy of the proposed biosensor system is well within ± 1.5%.
The system can be used for real time analysis of glucose
concentration in the field such as, food and fermentation and clinical
(In-Vitro) applications.
Abstract: The objective of current issue was to develop a model
of testicular herpes simplex virus (HSV) type I infection for
assessment of viral effect on fertility. 56 male mice were inoculated
intraperitoneally with different concentrations of HSV on 8 day post
partum. It was revealed that the optimal dose was 100 plaque
forming units per mice as it provided testicular infection in 100% of
survivors. HSV proteins were detected both in somatic and germ
cells (spermatogonia, spermatocytes, spermatides). Although DNA
load in testis was descending from 3 to 28 days post infection only
12.5% of infected males had offspring after mating with uninfected
females comparing to 87.5% in control (p=0.012). These results are
the first direct evidence for HSV impact in male sterility. Prepuberal
mice appeared to be a suitable model for investigation of
pathogenesis of virus-associated fertility disorders.
Abstract: Contamination of heavy metals represents one of the
most pressing threats to water and soil resources as well as human
health. Phytoremediation can be potentially used to remediate metalcontaminated
sites. A major step towards the development of
phytoremediation of heavy metal impacted soils is the discovery of
the heavy metal hyperaccumulation in plants. In this study, the
several established criteria to define a hyperaccumulator plant were
applied. The case study was represented by a mining area in
Hamedan province in the central west part of Iran. Obtained results
showed that the most of sampled species were able to grow on
heavily metal-contaminated soils and also were able to accumulate
extraordinarily high concentrations of some metals such as Zn, Mn,
Cu, Pb and Fe. Using the most common criteria, Euphorbia
macroclada and Centaurea virgata can be classified as
hyperaccumulators of some measured heavy metals and, therefore,
they have suitable potential for phytoremediation of contaminated
soils.
Abstract: Oleic acid (C18:1) play an important role in
proliferation of fat cells. In this study, the effect of oleate on cells
viability in 3T3-L1 cells (fat cells) was investigated. The 3T3-L1
cells were treated with various concentrations of oleate in the
presence of 23 mM glucose. Oleate was added to adipogenic media
(day 0) to investigate the influence of oleate on proliferation of
postconfluent preadipocytes after 24 h induction. 0.1 mM oleate
promoted cell division by increasing 33.9% number of cells from
basal control in postconfluent preadipocytes. However, there were no
significantly different in cells viability with control cells when oleate
concentrations were increased up to 0.5 mM. When added to
differentiated adipocytes (day 12) for 48 h, the number of cells
decreased as oleate concentrations increased. 92.7% of cells lost
demonstrated apoptosis and necrosis after 48 h with 0.5 mM oleate.
The fluorochrome staining was examined under fluorescence
microscopy using acridine orange and ethidium bromide double
staining. Furthermore, the presence of high lactate (60.6% increased
from basal control) released into plasma has shown the direct
cytotoxicity of 0.5 mM oleate on adipocytes.
Abstract: Environmental impact assessment (EIA) is a procedure tool of environmental management for identifying, predicting, evaluating and mitigating the adverse effects of development proposals. EIA reports usually analyze how the amounts or concentrations of pollutants obey the relevant standards. Actually, many analytical tools can deepen the analysis of environmental impacts in EIA reports, such as life cycle assessment (LCA) and environmental risk assessment (ERA). Life cycle impact assessment (LCIA) is one of steps in LCA to introduce the causal relationships among environmental hazards and damage. Incorporating the LCIA concept into ERA as an integrated tool for EIA can extend the focus of the regulatory compliance of environmental impacts to determine of the significance of environmental impacts. Sometimes, when using integrated tools, it is necessary to consider fuzzy situations due to insufficient information; therefore, ERA should be generalized to fuzzy risk assessment (FRA). Finally, the use of the proposed methodology is demonstrated through the study case of the expansion plan of the world-s largest plastics processing factory.
Abstract: Mercury adsorption on soil was investigated at
different ionic strengths using Ca(NO3)2 as a background electrolyte.
Results fitted the Langmuir equation and the adsorption isotherms
reached a plateau at higher equilibrium concentrations. Increasing
ionic strength decreased the sorption of mercury, due to the
competition of Ca ions for the sorption sites in the soils. The
influence of ionic strength was related to the mechanisms of heavy
metal sorption by the soil. These results can be of practical
importance both in the agriculture and contaminated soils since the
solubility of mercury in soils are strictly dependent on the adsorption
and release process.
Abstract: The aim of this study was to synthesize the single
walled carbon nanotubes (SWCNTs) and determine their hydrogen
storage capacities. SWCNTs were firstly synthesized by chemical
vapor deposition (CVD) of acetylene (C2H2) on a magnesium oxide
(MgO) powder impregnated with an iron nitrate (Fe(NO3)3·9H2O)
solution. The synthesis parameters were selected as: the synthesis
temperature of 800°C, the iron content in the precursor of 5% and the
synthesis time of 30 min. Purification process of SWCNTs was
fulfilled by microwave digestion at three different temperatures (120,
150 and 200 °C), three different acid concentrations (0.5, 1 and 1.5
M) and for three different time intervals (15, 30 and 60 min). Nitric
acid (HNO3) was used in the removal of the metal catalysts. The
hydrogen storage capacities of the purified materials were measured
using volumetric method at the liquid nitrogen temperature and gas
pressure up to 100 bar. The effects of the purification conditions such
as temperature, time and acid concentration on hydrogen adsorption
were investigated.
Abstract: A self-association model has been used to understand
the concentration dependence of free energy of mixing (GM), heat of
mixing (HM), entropy of mixing (SM), activity (a) and microscopic
structures, such as concentration fluctuation in long wavelength limit
(Scc(0)) and Warren-Cowley short range order parameter ( 1
α )for Cu-
Tl molten alloys at 1573K. A comparative study of surface tension of
the alloys in the liquid state at that temperature has also been carried
out theoretically as function of composition in the light of Butler-s
model, Prasad-s model and quasi-chemical approach. Most of the
computed thermodynamic properties have been found in agreement
with the experimental values. The analysis reveals that the Cu-Tl
molten alloys at 1573K represent a segregating system at all
concentrations with moderate interaction. Surface tensions computed
from different approaches have been found to be comparable to each
other showing increment with the composition of copper.
Abstract: Stevia rebaudiana Bertoni (natural sweetener) belongs
to Asteraceae family and can be used as substitute of artificial
sweeteners for diabetic patients. Conventionally, it is cultivated by
seeds or stem cutting, but seed viability rate is poor. A protocol for
callus induction and multiplication was developed to produce large
no. of calli in short period. Surface sterilized nodal, leaf and root
explants were cultured on Murashige and Skoog (MS) medium with
different concentrations of plant hormone like, IBA, kinetin, NAA,
2,4-D, and NAA in combination with 2,4-D. 100% callusing was
observed from leaf explants cultured on combination of NAA and
2,4-D after three weeks while with 2,4-D, only 10% callusing was
observed. Calli obtained from leaf and root explants were shiny green
while with nodal explants it was hard and brown. The present
findings deal with induction of callusing in Stevia to achieve the
rapid callus multiplication for study of steviol glycosides in callus
culture.
Abstract: We present a label-free biosensor based on
electrochemical impedance spectroscopy for the detection of proinflammatory
cytokine Tumor Necrosis Factor (TNF-α). Secretion of
TNF-α has been correlated to the onset of various diseases including
rheumatoid arthritis, Crohn-s disease etc. Gold electrodes were
patterned on a silicon substrate and self assembled monolayer of
dithiobis-succinimidyl propionate was used to develop the biosensor
which achieved a detection limit of ~57fM. A linear relationship was
also observed between increasing TNF-α concentrations and chargetransfer
resistance within a dynamic range of 1pg/ml – 1ng/ml.
Abstract: Application of pesticides in the paddy fields has
deleterious effects on non-target organisms including cyanobacteria
which are photosynthesizing and nitrogen fixing micro-organisms
contributing significantly towards soil fertility and crop yield.
Pesticide contamination in the paddy fields has manifested into a
serious global environmental concern. To study the effect of one such
pesticide, three cyanobacterial strains; Anabaena fertilissima,
Aulosira fertilissima and Westiellopsis prolifica were selected for
their stress responses to an Organochlorine insecticide - 6, 7, 8, 9, 10,
10-hexachloro-1, 5, 5a, 6, 9, 9a-hexahydro-6, 9-methano-2, 4, 3-
benzodioxathiepine-3-oxide, with reference to their photosynthesic
pigments-chlorophyll-a and carotenoids as well as accessory
pigments-phycobiliproteins (phycocyanin, allophycocyanin and
phycoerythrin), stress induced biochemical metabolites like
carbohydrates, proteins, amino acids, phenols and enzymes-nitrate
reductase, glutamine synthetase and succinate dehydrogenase. All
the three cyanobacterial strains were adversely affected by the
insecticide doses and inhibition was dose dependent. Reduction in
photosynthetic and accessory pigments, metabolites, nitrogen fixing
and respiratory enzymes of the test organisms were accompanied
with an initial increase in their total protein at lower Organochlorine
doses. On the other hand, increased amount of phenols in all the
insecticide treated concentrations was indicative of stressed activities
of the organisms.