Abstract: Yogurts are prepared by fermenting milk with bacterial cultures consisting of a mixture of Streptococcus ssp. thermophilus and Lactobacillus delbrueckii ssp. bulgaricus. The main aim of this investigation was to develop a majority goat yogurt, with the addition of sheep milk in order to have a final product with good physicochemical quality properties and sensorial attributes. Four types of yogurts were prepared presenting the following proportion of goat and sheep milk respectively: C100 – 100%; C80 – 80%/20%; C60 – 60%/40%; C50 – 50%/50%. The goat milk was from the Serrana Jarmelista breed and the sheep milk from the Serra da Estrela breed. The inclusion of sheep milk improved attractiveness to consumers, and it also improved the nutritional value of the product, mainly the fatty acid and mineral contents. The C50 yogurt was preferred by 28% of the panellists, followed by the C100 with 16% and the commercial cow yogurt was 40% of preferences.
Abstract: For many chemical and biological processes, the understanding of the mixing phenomenon and flow behavior in a stirred tank is of major importance. A three-dimensional numerical study was performed using the software Fluent, to study the flow field in a stirred tank with a Rushton turbine. In this work, we first studied the flow generated in the tank with a Rushton turbine. Then, we studied the effect of the variation of turbine’s submergence on the thermodynamic quantities defining the flow field. For that, four submergences were considered, while maintaining the same rotational speed (N =250rpm). This work intends to optimize the aeration performances of a Rushton turbine in a stirred tank.
Abstract: The mathematical modeling of different biological
processes is usually used to predict or assess behavior of systems in
which these processes take place. This study deals with mathematical
and computer modeling of bi-substrate enzymatic reactions with
ping-pong mechanism, which play an important role in different
biochemical pathways. Besides that, three models of competitive
inhibition were designed using different software packages. The main
objective of this study is to represent the results from in silico
investigation of bi-substrate enzymatic reactions with ordered pingpong
mechanism in the presence of competitive inhibitors, as well as
to describe in details the inhibition effects. The simulation of the
models with certain kinetic parameters allowed investigating the
behavior of reactions as well as determined some interesting aspects
concerning influence of different cases of competitive inhibition.
Simultaneous presence of two inhibitors, competitive to the S1 and S2
substrates have been studied. Moreover, we have found the pattern of
simultaneous influence of both inhibitors.
Abstract: Atrazine, a herbicide widely used in sugarcane and corn production, is a frequently detected groundwater contaminant. An atrazine-degrading bacterium, strain KB02, was obtained from long-term atrazine-treated sugarcane field soils in Kanchanaburi province of Thailand. Strain KB02 had a rod-to-coccus morphological cycle during growth. Sequence analysis of the PCR product indicated that the 16S rRNA gene in strain KB02 was ranging from 97-98% identical to the same region in Klebsiella sp. Based on biochemical, physiological analysis and 16S rDNA sequence analysis of one representative isolate, strain KB02, the isolates belong to the genus Klebsiella in the family Enterobacteriaceae. Interestingly that the various primers for atzA, B and C failed to amplify genomic DNA of strain KB02. Whereas the expected PCR product of atzA, B and C were obtained from the reference strain, Arthrobacter sp. strain KU001.
Abstract: Gluconic acid is one of interesting chemical products
in industries such as detergents, leather, photographic, textile, and
especially in food and pharmaceutical industries. Fermentation is an
advantageous process to produce gluconic acid. Mathematical
modeling is important in the design and operation of fermentation
process. In fact, kinetic data must be available for modeling. The
kinetic parameters of gluconic acid production by Aspergillus niger
in batch culture was studied in this research at initial substrate
concentration of 150, 200 and 250 g/l. The kinetic models used were
logistic equation for growth, Luedeking-Piret equation for gluconic
acid formation, and Luedeking-Piret-like equation for glucose
consumption. The Kinetic parameters in the model were obtained by
minimizing non linear least squares curve fitting.
Abstract: Banana is one of the most consumed fruits in the tropics and subtropics. Brazil accounts for about 9% of the world banana production. However, the production losses are as high as 30 to 40% and even much higher in some developing countries. The green banana flour is a complex carbohydrate source, including a high total starch (73.4%), resistant starch (17.5%) with functional properties. Gamma irradiation is considered to be an alternative method for food preservation. It has been performed due to the need of extending the shelf - life of foods, whilst maintaining their safety and avoiding one of the main concerns: the nutrient loss. In this work data about on the effects of ionizing radiation on the physicochemical analysis (carbohydrate, proteins, lipids, alimentary fiber, moistures and ashes) of Brazilian functional products (biscuits and bread) of the green banana pulp are presented. The caloric value was calculated. No significant difference was observed between the samples of irradiated and non – irradiated green banana biscuits with the following determinations: carbohydrates, proteins, alimentary fiber and ashes. Only a small significant difference was found in lipids (macronutrients). The results of physical chemical analysis of the irradiated and non- irradiated green banana bread non- irradiated showed no significant difference with the following determinations: carbohydrates, lipids (macronutrients), moisture, ashes and caloric value. A small difference was found in proteins (macronutrients). Irradiation of functional products (biscuits and bread) with doses of 1 and 3kGy maintained their original macronutrients content, showing good radioresistance.
Abstract: Seasonal variability of nutrients concentration in the Baltic Sea using the 3D ecosystem numerical model 3D-CEMBS has been investigated. Additionally this study shows horizontal and vertical distribution of nutrients in the Baltic Sea. Model domain is an extended Baltic Sea area divided into 600x640 horizontal grid cells. Aside from standard hydrodynamic parameters 3D-CEMBS produces modeled ecological variables such as: three types of phytoplankton, two detrital classes, dissolved oxygen and the nutrients (nitrate, ammonium, phosphate and silicate). The presented model allows prediction of parameters that describe distribution of nutrients concentration and phytoplankton biomass. 3D-CEMBS can be used to study the effect of different hydrodynamic and biogeochemical processes on distributions of these variables in a larger scale.
Abstract: Technology of thin film deposition is of interest in
many engineering fields, from electronic manufacturing to corrosion
protective coating. A typical deposition process, like that developed
at the University of Eindhoven, considers the deposition of a thin,
amorphous film of C:H or of Si:H on the substrate, using the
Expanding Thermal arc Plasma technique. In this paper a computing
procedure is proposed to simulate the flow field in a deposition
chamber similar to that at the University of Eindhoven and a
sensitivity analysis is carried out in terms of: precursor mass flow
rate, electrical power, supplied to the torch and fluid-dynamic
characteristics of the plasma jet, using different nozzles. To this
purpose a deposition chamber similar in shape, dimensions and
operating parameters to the above mentioned chamber is considered.
Furthermore, a method is proposed for a very preliminary evaluation
of the film thickness distribution on the substrate. The computing
procedure relies on two codes working in tandem; the output from
the first code is the input to the second one. The first code simulates
the flow field in the torch, where Argon is ionized according to the
Saha-s equation, and in the nozzle. The second code simulates the
flow field in the chamber. Due to high rarefaction level, this is a
(commercial) Direct Simulation Monte Carlo code. Gas is a mixture
of 21 chemical species and 24 chemical reactions from Argon plasma
and Acetylene are implemented in both codes. The effects of the
above mentioned operating parameters are evaluated and discussed
by 2-D maps and profiles of some important thermo-fluid-dynamic
parameters, as per Mach number, velocity and temperature. Intensity,
position and extension of the shock wave are evaluated and the
influence of the above mentioned test conditions on the film
thickness and uniformity of distribution are also evaluated.
Abstract: We demonstrate a nonfaradaic electrochemical impedance spectroscopy measurement of biochemically modified gold plated electrodes using a two-electrode system. The absence of any redox indicator in the impedance measurements provide more precise and accurate characterization of the measured bioanalyte at molecular resolution. An equivalent electrical circuit of the electrodeelectrolyte interface was deduced from the observed impedance data of saline solution at low and high concentrations. The detection of biomolecular interactions was fundamentally correlated to electrical double-layer variation at modified interface. The investigations were done using 20mer deoxyribonucleic acid (DNA) strands without any label. Surface modification was performed by creating mixed monolayer of the thiol-modified single-stranded DNA and a spacer thiol (mercaptohexanol) by a two-step self-assembly method. The results clearly distinguish between the noncomplementary and complementary hybridization of DNA, at low frequency region below several hundreds Hertz.
Abstract: Air quality in Setapak district of Kuala Lumpur was
studied by analysing the rainwater chemical composition using ion
chromatography method. Twelve sampling sites were selected and
120 rainwater samples were collected in the period of 10 weeks. The
results of this study were compared to the earlier published data and
the evaluation showed that the NO3
- ion concentration increased from
0.41 to 3.32 ppm, while SO4
2- ion concentration increased from 0.39
to 3.26 ppm over the past two decades that is mostly due to rapid
urban development of the city. However, it was found that the
chemical composition for both residential and industrial areas does
not have significant difference. Most of the rainwater samples
showed alkaline pH (pH > 5.6). The possible factors for such alkaline
pH in rainwater samples are assumed to be the marine sources,
biomass burning and alkaline character of soil particles.
Abstract: Corrosion of metallic water pipelines buried below
ground surface is a function of the nature of the surrounding soil and
groundwater. This gives the importance of knowing the physical and
chemical characteristics of the pipe-s surrounding environment. The
corrosion of externally – unprotected metallic water pipelines,
specially ductile iron pipes, in localities with aggressive soil
conditions is becoming a significant problem. Anticorrosive
protection for metallic water pipelines, their fittings and accessories
is very important, because they may be attached by corrosion with
time. The tendency of a metallic substrate to corrode is a function of
the surface characteristics of the metal and of the metal/protective
film interface, the physical, electrical and electrochemical properties
of the film, and the nature of the environment in which the pipelines
system is placed. In this work the authors have looked at corrosion
problems of water pipelines and their control. The corrosive
properties of groundwater and soil environments are reviewed, and
parameters affecting corrosion are discussed. The purpose of this
work is to provide guidelines for materials selection in water and soil
environments, and how the water pipelines can be protected against
metallic corrosion.
Abstract: In this research, effect of combustion reaction
mechanism on direct initiation of detonation has been studied
numerically. For this purpose, reaction mechanism has been
simulated by using a three-step chemical kinetics model. The reaction
scheme consists sequentially of a chain-initiation and chainbranching
step, followed by a temperature -independent chaintermination.
In a previous research, the effect of chain-branching on
the direct initiation of detonation is studied. In this research effect of
chain-initiation on direct initiation of detonation is investigated. For
the investigation, first a characteristic time (τ) for each step of
mechanism, which includes effect of different kinetics parameters, is
defined. Then the effect of characteristic time of chain-initiation (τI)
on critical initiation energy is studied. It is seen that increasing τI,
causes critical initiation energy to be increased. Drawing detonation's
shock pressure diagrams for different cases, shows that in small value
of τI , kinetics has more important effect on the behavior of the wave.
Abstract: This study investigates CO2 mitigation by methanol
synthesis from flue gas CO2 and H2 generation through water
electrolysis. Electrolytic hydrogen generation is viable provided that
the required electrical power is supplied from renewable energy
resources; whereby power generation from renewable resources is yet
commercial challenging. This approach contribute to zero-emission,
moreover it produce oxygen which could be used as feedstock for
chemical process. At ZPC, however, oxygen would be utilized
through partial oxidation of methane in autothermal reactor (ATR);
this makes ease the difficulties of O2 delivery and marketing. On the
other hand, onboard hydrogen storage and consumption; in methanol
plant; make the project economically more competitive.
Abstract: Huge losses in apple production are caused by pathogens that cannot be seen shortly after harvest. After-harvest thermotherapy treatments can considerably improve control of storage diseases on apples and become an alternative to chemical pesticides. In the years 2010-2012 carried out research in this area. Apples of 'Topaz' cultivar were harvested at optimal maturity time for long storage and subject to water bath treatment at 45, 50, 52, 55°C for 60, 120, 180 and 240 seconds. The control was untreated fruits. After 12 and 24 weeks and during so called simulated trade turnover the fruits were checked for their condition and the originators of diseases were determined by using the standard phytopathological methods. The most common originator of 'Topaz' apple infection during storage were the fungi of genus Gloeosporium. In this paper it was proven that for effective protection of 'Topaz' apples against diseases, thermotherapy by using water treatments at temperature range of 50-52°C is quite sufficient.
Abstract: The manufacturing transmission line tower parts has
being generated hazardous waste which is required proper disposal
of waste for protection of land pollution. Manufacturing Process in
the manufacturing of steel angle, plates, pipes, channels are passes
through conventional, semi automatic and CNC machines for
cutting, marking, punching, drilling, notching, bending operations.
All fabricated material Coated with thin layer of Zinc in Galvanizing
plant where molten zinc is used for coating. Prior to Galvanizing,
chemical like 33% concentrated HCl Acid, ammonium chloride and
d-oil being used for pretreatment of iron. The bath of water with
sodium dichromate is used for cooling and protection of the
galvanized steel. For the heating purpose the furnace oil burners are
used. These above process the Zinc dross, Zinc ash, ETP sludge and
waste pickled acid generated as hazardous waste. The RPG has
made captive secured land fill site, since 1997 since then it was
using for disposal of hazardous waste after completion of SLF
(Secured land fill) site. The RPG has raised height from ground
level then now it is being used for disposal of waste as he designed
the SLF after in creasing height of from GL it is functional without
leach ate or adverse impacts in the environment.
Abstract: The purpose of this study is to identify and evaluate
the scale of implementation of Just-In-Time (JIT) in the different industrial sectors in the Middle East. This study analyzes the empirical data collected by a questionnaire survey distributed to
companies in three main industrial sectors in the Middle East, which
are: food, chemicals and fabrics. The following main hypotheses is formulated and tested: (The requirements of JIT application differ
according to the type of industrial sector).Descriptive statistics and Box plot analysis were used to examine the hypotheses. This study indicates a reasonable evidence for accepting the main hypotheses. It
reveals that there is no standard way to adopt JIT as a production system. But each industrial sector should concentrate in the
investment on critical requirements that differ according to the nature
and strategy of production followed in that sector.
Abstract: The effect of seed inoculation by VA- mycorrhiza and
different levels of phosphorus fertilizer on growth and yield of
sunflower (Azargol cultivar) was studied in experiment farm of
Islamic Azad University, Karaj Branch during 2008 growing season.
The experiment treatments were arranged in factorial based on a
complete randomized block design with three replications. Four
phosphorus fertilizer levels of 25%, 50% 75% and 100% P
recommended with two levels of Mycorrhiza: with and without
Mycorrhiza (control) were assigned in a factorial combination.
Results showed that head diameter, number of seeds in head, seed
yield and oil yield were significantly higher in inoculated plants than
in non-inoculated plants. Head diameter, number of seeds in head,
1000 seeds weight, biological yield, seed yield and oil yield increased
with increasing P level above 75% P recommended in non-inoculated
plants, whereas no significant difference was observed between 75%
and 100% P recommended. The positive effect of mycorrhizal
inoculation decreased with increasing P levels due to decreased
percent root colonization at higher P levels. According to the results
of this experiment, application of mycorrhiza in present of 50% P
recommended had an appropriate performance and could increase
seed yield and oil production to an acceptable level, so it could be
considered as a suitable substitute for chemical phosphorus fertilizer
in organic agricultural systems.
Abstract: This paper presents a model for the characterization
and selection of beeswaxes for use as base substitute tissue for the
manufacture of objects suitable for external radiotherapy using
megavoltage photon beams. The model of characterization was
divided into three distinct stages: 1) verification of aspects related to
the origin of the beeswax, the bee species, the flora in the vicinity of
the beehives and procedures to detect adulterations; 2) evaluation of
physical and chemical properties; and 3) evaluation of beam
attenuation capacity. The chemical composition of the beeswax
evaluated in this study was similar to other simulators commonly
used in radiotherapy. The behavior of the mass attenuation coefficient
in the radiotherapy energy range was comparable to other simulators.
The proposed model is efficient and enables convenient assessment
of the use of any particular beeswax as a base substitute tissue for
radiotherapy.
Abstract: The heavy metal contamination of the technogenous
sediments and soils at the investigated dump-field show irregular
planar distribution. Also the heavy metal content in the surface water,
drainage water and in the groundwater was studied both in the dry as
well as during the rainy periods. The cementation process causes
substitution of iron by copper. Natural installation and development
of plant species was observed at the old mine waste dumps, specific
to the local chemical conditions such as low content of essential
nutrients and high content of heavy metals. The individual parts of
the plant tissues (roots, branches/stems, leaves/needles, flowers/
fruits) are contaminated by heavy metals and tissues are damaged
differently, respectively.
Abstract: An evaluation of the PCBs residues in the surface soils from Bacninh, Vietnam was carried out. Sixty representative soil samples were collected from the centre of Bacninh and three surrounding districts. The analyzed results indicated the wide extent of contamination of total PCBs in Bacninh. In industrial and urban zones, total PCBs concentrations ranged from ranged from