Abstract: In this study, a mathematical model was proposed and
the accuracy of this model was assessed to predict the growth of
Pseudomonas aeruginosa and rhamnolipid production under nitrogen
limiting (sodium nitrate) fed-batch fermentation. All of the
parameters used in this model were achieved individually without
using any data from the literature.
The overall growth kinetic of the strain was evaluated using a
dual-parallel substrate Monod equation which was described by
several batch experimental data. Fed-batch data under different
glycerol (as the sole carbon source, C/N=10) concentrations and feed
flow rates were used to describe the proposed fed-batch model and
other parameters. In order to verify the accuracy of the proposed
model several verification experiments were performed in a vast
range of initial glycerol concentrations. While the results showed an
acceptable prediction for rhamnolipid production (less than 10%
error), in case of biomass prediction the errors were less than 23%. It
was also found that the rhamnolipid production by P. aeruginosa was
more sensitive at low glycerol concentrations.
Based on the findings of this work, it was concluded that the
proposed model could effectively be employed for rhamnolipid
production by this strain under fed-batch fermentation on up to 80 g l-
1 glycerol.
Abstract: A shaft-type activated sludge reactor has been
developed in order to study the feasibility of high-rate wastewater
treatment. The reactor having volume of about 14.5 L was operated
with the acclimated mixed activated sludge under batch and
continuous mode using a synthetic wastewater as feed. The batch
study was performed with varying chemical oxygen demand (COD)
concentrations of 1000–3500 mg·L-1 for a batch period up to 9 h. The
kinetic coefficients: Ks, k, Y and kd were obtained as 2040.2 mg·L-1
and 0.105 h-1, 0.878 and 0.0025 h-1 respectively from Monod-s
approach. The continuous study showed a stable and steady state
operation for a hydraulic retention time (HRT) of 8 h and influent
COD of about 1000 mg·L-1. A maximum COD removal efficiency of
about 80% was attained at a COD loading rate and food-tomicroorganism
(F/M) ratio (COD basis) of 3.42 kg·m-3d-1 and 1.0
kg·kg-1d-1 respectively under a HRT of 8 h. The reactor was also
found to handle COD loading rate and F/M ratio of 10.8 kg·m-3d-1
and 2.20 kg·kg-1d-1 respectively showing a COD removal efficiency
of about 46%.
Abstract: Surgical site infections (SSIs) are the most common
nosocomial infection in surgical patients resulting in significant
increases in postoperative morbidity and mortality. The commonly
causative bacteria developed resistance to virtually all antibiotics
available. The aim of this study was to isolation and identification the
most common bacteria that cause SSIs in Medical Research Institute,
and to compare their sensitivity to selected group of antibiotics and
natural products (garlic, oregano, olive, and Nigella sativa oils). The
isolated pathogens collected from infected surgical wounds were
identified, and their sensitivities to the antibiotics commonly
available for clinical use, and also to the different concentrations of
the used natural products were investigated. The results indicate to
the potential therapeutic effect of the tested natural products in
treatment of surgical wound infections.
Abstract: Minimum Quantity Lubrication (MQL) technique
obtained a significant attention in machining processes to reduce
environmental loads caused by usage of conventional cutting fluids.
Recently nanofluids are finding an extensive application in the field
of mechanical engineering because of their superior lubrication and
heat dissipation characteristics. This paper investigates the use of a
nanofluid under MQL mode to improve grinding characteristics of
Ti-6Al-4V alloy. Taguchi-s experimental design technique has been
used in the present investigation and a second order model has been
established to predict grinding forces and surface roughness.
Different concentrations of water based Al2O3 nanofluids were
applied in the grinding operation through MQL setup developed in
house and the results have been compared with those of conventional
coolant and pure water. Experimental results showed that grinding
forces reduced significantly when nano cutting fluid was used even at
low concentration of the nano particles and surface finish has been
found to improve with higher concentration of the nano particles.
Abstract: The main objectives of this paper are to measure
pollutants concentrations in the oil refinery area in Kuwait over three
periods during one year, obtain recent emission inventory for the
three refineries of Kuwait, use AERMOD and the emission inventory
to predict pollutants concentrations and distribution, compare model
predictions against measured data, and perform numerical
experiments to determine conditions at which emission rates and the
resulting pollutant dispersion is below maximum allowable limits.
Abstract: Among the technologies available to reduce methane
emitted from the pig industry, biofiltration seems to be an effective
and inexpensive solution. In methane (CH4) biofiltration, nitrogen is
an important macronutrient for the microorganisms growth. The
objective of this research project was to study the effect of
ammonium (NH4
+) on the performance, the biomass production and
the nitrogen conversion of a biofilter treating methane. For NH4
+
concentrations ranging from 0.05 to 0.5 gN-NH4
+/L, the CH4 removal
efficiency and the dioxide carbon production rate decreased linearly
from 68 to 11.8 % and from 7.1 to 0.5 g/(m3-h), respectively. The dry
biomass content varied from 4.1 to 5.8 kg/(m3 filter bed). For the
same range of concentrations, the ammonium conversion decreased
while the specific nitrate production rate increased. The specific
nitrate production rate presented negative values indicating
denitrification in the biofilter.
Abstract: This study investigated the relationship between urban
and rural ozone concentrations and quantified the extent to which
ambient rural conditions and the concentrations of other pollutants
can be used to predict urban ozone concentrations. The study
describes the variations of ozone in weekday and weekends as well as
the daily maximum recorded at selected monitoring stations. The
results showed that Putrajaya station had the highest concentrations
of O3 on weekend due the titration of NO during the weekday.
Additionally, Jerantut had the lowest average concentration with a
reading value high on Wednesdays. The comparisons of average and
maximum concentrations of ozone for the three stations showed that
the strongest significant correlation is recorded in Jerantut station
with the value R2= 0.769. Ozone concentrations originating from a
neighbouring urban site form a better predictor to the urban ozone
concentrations than widespread rural ozone at some levels of
temporal averaging. It is found that in urban and rural of Malaysian
peninsular, the concentration of ozone depends on the concentration
of NOx and seasonal meteorological factors. The HYSPLIT Model
(the northeast monsoon) showed that the wind direction can also
influence the concentration of ozone in the atmosphere in the studied
areas.
Abstract: The aim of this studywas toinvestigate the effect
ofrunning classification (sprint, middle, and long distance)and two
distances on blood lactate (BLa), heart rate (HR), and rating of
perceived exertion (RPE) Borg scale ratings in collegiate athletes. On
different days, runners (n = 15) ran 400m and 1600m at a five min
mile pace, followed by a two min 6mph jog, and a two min 3mph
walk as part of the cool down. BLa, HR, and RPE were taken at
baseline, post-run, plus 2 and 4 min recovery times. The middle and
long distance runners exhibited lower BLa concentrations than sprint
runners after two min of recovery post 400 m runs, immediately after,
and two and four min recovery periods post 1600 m runs. When
compared to sprint runners, distance runners may have exhibited the
ability to clear BLa more quickly, particularly after running 1600 m.
Abstract: A vast array of biological materials, especially algae have received increasing attention for heavy metal removal. Algae have been proven to be cheaper, more effective for the removal of metallic elements in aqueous solutions. A fresh water algal strain was isolated from Zoo Lake, Johannesburg, South Africa and identified as Desmodesmus sp. This paper investigates the efficacy of Desmodesmus sp.in removing heavy metals contaminating the Wonderfonteinspruit Catchment Area (WCA) water bodies. The biosorption data fitted the pseudo-second order and Langmuir isotherm models. The Langmuir maximum uptakes gave the sequence: Mn2+>Ni2+>Fe2+. The best results for kinetic study was obtained in concentration 120 ppm for Fe3+ and Mn2+, whilst for Ni2+ was at 20 ppm, which is about the same concentrations found in contaminated water in the WCA (Fe3+115 ppm, Mn2+ 121 ppm and Ni2+ 26.5 ppm).
Abstract: Alcohol and water extracts of Cymbopogon citratus
was investigated for anti-bacterial properties and phytochemical
constituents. The extract was screened against four gram-negative
bacteria Escherichia coli, Klebsiella pneumoniae, Pseudomonas
aeruginosa, Proteus vulgaris) and two grampositive bacteria Bacillus
subtilis and Staphylococcus aureus at four different concentrations
(1:1, 1:5, 1:10 and 1:20) using disc diffusion method. The antibacterial
examination was by disc diffusion techniques, while the
photochemical constituents were investigated using standard
chemical methods. Results showed that the extracts inhibited the
growth of standard and local strains of the organisms used. The
treatments were significantly different (P = 0.05). The minimum
inhibitory concentration of the extracts against the tested
microorganisms ranged between 150mg/ml and 50mg/ml. The
alcohol extracts were found to be generally more effective than the
water extract. The photochemical analysis revealed the presence of
alkaloids and phenol but absence of cardiac and cyanogenic
glycosides. The presence of alkaloid and phenols were inferred as
being responsible for the anti-bacterial properties of the extracts.
Abstract: Trace element speciation of an integrated soil
amendment matrix was studied with a modified BCR sequential
extraction procedure. The analysis included pseudo-total
concentration determinations according to USEPA 3051A and
relevant physicochemical properties by standardized methods. Based
on the results, the soil amendment matrix possessed neutralization
capacity comparable to commercial fertilizers. Additionally, the
pseudo-total concentrations of all trace elements included in the
Finnish regulation for agricultural fertilizers were lower than the
respective statutory limit values. According to chemical speciation,
the lability of trace elements increased in the following order: Hg <
Cr < Co < Cu < As < Zn < Ni < Pb < Cd < V < Mo < Ba. The
validity of the BCR approach as a tool for chemical speciation was
confirmed by the additional acid digestion phase. Recovery of trace
elements during the procedure assured the validity of the approach
and indicated good quality of the analytical work.
Abstract: Macrophomina phaseolina is a devastating soil-borne
fungal plant pathogen that causes charcoal rot disease in many
economically important crops worldwide. So far, no registered
fungicide is available against this plant pathogen. This study was
planned to examine the antifungal activity of an allelopathic grass
Cenchrus pennisetiformis (Hochst. & Steud.) Wipff. for the
management of M. phaseolina isolated from cowpea [Vigna
unguiculata (L.) Walp.] plants suffering from charcoal rot disease.
Different parts of the plants viz. inflorescence, shoot and root were
extracted in methanol. Laboratory bioassays were carried out using
different concentrations (0, 0.5, 1.0, …, 3.0 g mL-1) of methanolic
extracts of the test allelopathic grass species to assess the antifungal
activity against the pathogen. In general, extracts of all parts of the
grass exhibited antifungal activity. All the concentrations of
methanolic extracts of shoot and root significantly reduced fungal
biomass by 20–73% and 40–80%, respectively. Methanolic shoot
extract was fractionated using n-hexane, chloroform, ethyl acetate
and n-butanol. Different concentrations of these fractions (3.125,
6.25, …, 200 mg mL-1) were analyzed for their antifungal activity.
All the concentrations of n-hexane fraction significantly reduced
fungal biomass by 15–96% over corresponding control treatments.
Higher concentrations (12.5–200 mg mL-1) of chloroform, ethyl
acetate and n-butanol also reduced the fungal biomass significantly
by 29–100%, 46–100% and 24–100%, respectively.
Abstract: Earthquakes are natural phenomena that occur with influence of a lot of parameters such as seismic activity, changing in the ground waters' motion, changing in the water-s temperature, etc. On the other hand, the radon gas concentrations in soil vary as nonlinear generally with earthquakes. Continuous measurement of the soil radon gas is very important for determination of characteristic of the seismic activity. The radon gas changes as continuous with strain occurring within the Earth-s surface during an earthquake and effects from the physical and the chemical processes such as soil structure, soil permeability, soil temperature, the barometric pressure, etc. Therefore, at the modeling researches are notsufficient to knowthe concentration ofradon gas. In this research, we determined relationships between radon emissions based on the environmental parameters and earthquakes occurring along the East Anatolian Fault Zone (EAFZ), Turkiye and predicted magnitudes of some earthquakes with the artificial neural network (ANN) model.
Abstract: The aim of our research was to evaluate the effects of
physical exercise on lipid profile and anthropometric characteristics
in young subjects, diagnosed with metabolic syndrome (MS). The
study has been developed during 28 weeks on 20 young obese
patients which have undertaken an intermittent submaximal exercise
program. After 28 weeks of physical activity, the results show
significant effects on anthropometric characteristics and serum lipid
profile of research subjects. Additionally, the results of this study
confirms the major correlation between the variations of
intraabdominal adiposity, determined ultrasonographycally,
and the changes of serum lipid concentrations, a better
correlation than it is used abdominal circumference or body
weight index.
Abstract: Restoration of endodontically treated teeth is a
common problem in dentistry, related to the fractures occurring in
such teeth and to concentration of forces little information regarding
variation of basic preparation guidelines in stress distribution has
been available. To date, there is still no agreement in the literature
about which material or technique can optimally restore
endodontically treated teeth. The aim of the present study was to
evaluate the influence of the core height and restoration materials on
corono-radicular restored upper first premolar. The first step of the
study was to achieve 3D models in order to analyze teeth, dowel and
core restorations and overlying full ceramic crowns. The FEM model
was obtained by importing the solid model into ANSYS finite
element analysis software. An occlusal load of 100 N was conducted,
and stresses occurring in the restorations, and teeth structures were
calculated. Numerical simulations provide a biomechanical
explanation for stress distribution in prosthetic restored teeth. Within
the limitations of the present study, it was found that the core height
has no important influence on the stress generated in coronoradicular
restored premolars. It can be drawn that the cervical regions
of the teeth and restorations were subjected to the highest stress
concentrations.
Abstract: The determination of sugars in foods is very
significant. Their relation in fact, can affect the chemical and
sensorial quality of the matrix (e.g., sweetness, pH, total acidity,
microbial stability, global acceptability) and can provide information
on food to optimize several selected technological processes. Three
stages of ripeness (green, yellow and red) of tomatoes (Lycopersicon
Esculentum cv. Elegance) at different harvest dates were evaluated.
Fruit from all harvests were exposed to different of ozone doses
(0.25, 0.50 and 1 mg O3/g tomatoes) and clean air for 5 day at 15
°C±2 and 90-95 % relative humidity. Then, fruits were submitted for
extraction and analysis after a day from the finish of exposure of each
stage. The concentrations of the glucose and fructose increased in the
tomatoes which were subjected to ozone treatments.
Abstract: Tea has several types of essential elements. Potassium,
magnesium and phosphorus are some examples of these elements.
Tea is widely used drink in Turkey, also some people puts a lemon
wedge to tea for different taste. In this study potassium, magnesium
and phosphorus contents after the hot water brewing of black and
green tea were determined by Optical Emission Spectroscopy (ICPOES).
Furthermore, how the lemon addition to teas affects the
concentrations of the potassium, magnesium and phosphorus
amount are investigated.
From the results, potassium, magnesium and phosphorus
concentrations are found as 3003.3, 597.1, 1167.2 ppm in black tea
and 3718.0, 3830.5, 376.4 ppm in green tea, respectively. After
lemon addition potassium, magnesium and phosphorus
concentrations are changed to 14930, 830.4, 1113.5 ppm in black tea
and 15460.0, 909.5, 1152.5 ppm in green tea, respectively.
It is seen that lemon addition affects some essential elements in
black and green Turkish teas.
Abstract: Vinegar or sour wine is a product of alcoholic and
subsequent acetous fermentation of sugary precursors derived from
several fruits or starchy substrates. This delicious food additive and
supplement contains not less than 4 grams of acetic acid in 100 cubic
centimeters at 20°C. Among the large number of bacteria that are
able to produce acetic acid, only few genera are used in vinegar
industry most significant of which are Acetobacter and
Gluconobacter. In this research we isolated and identified an
Acetobacter strain from Iranian apricot, a very delicious and sensitive
summer fruit to decay, we gathered from fruit's stores in Isfahan,
Iran. The main culture media we used were Carr, GYC, Frateur and
an industrial medium for vinegar production. We isolated this strain
using a novel miniature fermentor we made at Pars Yeema
Biotechnologists Co., Isfahan Science and Technology Town (ISTT),
Isfahan, Iran. The microscopic examinations of isolated strain from
Iranian apricot showed gram negative rods to cocobacilli. Their
catalase reaction was positive and oxidase reaction was negative and
could ferment ethanol to acetic acid. Also it showed an acceptable
growth in 5%, 7% and 9% ethanol concentrations at 30°C using
modified Carr media after 24, 48 and 96 hours incubation
respectively. According to its tolerance against high concentrations of
ethanol after four days incubation and its high acetic acid production,
8.53%, after 144 hours, this strain could be considered as a suitable
industrial strain for a production of a new type of vinegar, apricot
vinegar, with a new and delicious taste. In conclusion this is the first
report of isolation and identification of an Acetobacter strain from
Iranian apricot with a very good tolerance against high ethanol
concentrations as well as high acetic acid productivity in an
acceptable incubation period of time industrially. This strain could be
used in vinegar industry to convert apricot spoilage to a beneficiary
product and mentioned characteristics have made it as an amenable
strain in food and agricultural biotechnology.
Abstract: Continuous measurements and multivariate methods are applied in researching the effects of energy consumption on indoor air quality (IAQ) in a Finnish one-family house. Measured data used in this study was collected continuously in a house in Kuopio, Eastern Finland, during fourteen months long period. Consumption parameters measured were the consumptions of district heat, electricity and water. Indoor parameters gathered were temperature, relative humidity (RH), the concentrations of carbon dioxide (CO2) and carbon monoxide (CO) and differential air pressure. In this study, self-organizing map (SOM) and Sammon's mapping were applied to resolve the effects of energy consumption on indoor air quality. Namely, the SOM was qualified as a suitable method having a property to summarize the multivariable dependencies into easily observable two-dimensional map. Accompanying that, the Sammon's mapping method was used to cluster pre-processed data to find similarities of the variables, expressing distances and groups in the data. The methods used were able to distinguish 7 different clusters characterizing indoor air quality and energy efficiency in the study house. The results indicate, that the cost implications in euros of heating and electricity energy vary according to the differential pressure, concentration of carbon dioxide, temperature and season.
Abstract: This study was aimed to determine seasonal variations
of leaf nutrient concentrations to define nutrient needs related to
growing period and to compare irrigation programs in terms of
nutrient uptake. In this study,'Starkrimson Delicious' variety grafted
onto seedling rootstock was used during 2009-2010 growing seasons.
The study was conducted at E─ƒirdir Fruit Growing Research Station.
Leaf samples were taken in five different sample seasons (May, June,
July, August and September). Four different pan coefficients (0.50,
0.75, 1.0, 1.25) were applied during drip irrigation treatments in 7
days irrigation interval. Leaf K, Mg, Ca, P, Fe, Zn, Mn and Cu
concentrations were determined.
The results showed that among the seasonal changes, the highest
concentrations of K, Mg, P and Mn in leaves were recorded in May,
followed by a decrease in the other months, while in contrast Ca and
Fe showed the lowest concentration in May.
Results of the study demonstrate that among irrigation programs K
and Cu concentration in plants was significantly influenced. Cu
concentrations decreased with seasonal variations and different
irrigation programs. Thus, nutrient needs of 'Starkrimson Delicious'apple trees at different growth stages should be taken into
consideration before making effective fertilization program.