Abstract: This research presents the design and analysis of solar
air-conditioning systems particularly solar chimney which is a
passive strategy for natural ventilation, and demonstrates the
structures of these systems’ using Computational Fluid Dynamic
(CFD) and finally compares the results with several examples, which
have been studied experimentally and carried out previously. In order
to improve the performance of solar chimney system, highly efficient
sub-system components are considered for the design. The general
purpose of the research is to understand how efficiently solar
chimney systems generate cooling, and is to improve the efficient of
such systems for integration with existing and future domestic
buildings.
Abstract: This paper studies a mathematical model based on the
integral equations for dynamic analyzes numerical investigations of a
non-uniform or multi-material composite beam. The beam is
subjected to a sub-tangential follower force and elastic foundation.
The boundary conditions are represented by generalized
parameterized fixations by the linear and rotary springs. A
mathematical formula based on Euler-Bernoulli beam theory is
presented for beams with variable cross-sections. The non-uniform
section introduces non-uniformity in the rigidity and inertia of beams
and consequently, more complicated equilibrium who governs the
equation. Using the boundary element method and radial basis
functions, the equation of motion is reduced to an algebro-differential
system related to internal and boundary unknowns. A generalized
formula for the deflection, the slope, the moment and the shear force
are presented. The free vibration of non-uniform loaded beams is
formulated in a compact matrix form and all needed matrices are
explicitly given. The dynamic stability analysis of slender beam is
illustrated numerically based on the coalescence criterion. A realistic
case related to an industrial chimney is investigated.
Abstract: This paper treats different aspects of entropy measure
in classical information theory and statistical quantum mechanics, it
presents the possibility of extending the definition of Von Neumann
entropy to image and array processing. In the first part, we generalize
the quantum entropy using singular values of arbitrary rectangular
matrices to measure the randomness and the quality of denoising
operation, this new definition of entropy can be implemented to
compare the performance analysis of filtering methods. In the second
part, we apply the concept of pure state in quantum formalism
to generalize the maximum entropy method for narrowband and
farfield source localization problem. Several computer simulation
results are illustrated to demonstrate the effectiveness of the proposed
techniques.
Abstract: This paper presents the results obtained by numerical
simulation using the software ANSYS CFX-CFD for the air
pollutants dispersion in the atmosphere coming from the evacuation
of combustion gases resulting from the fuel combustion in an electric
thermal power plant. The model uses the Navier-Stokes equation to
simulate the dispersion of pollutants in the atmosphere. It is
considered as important factors in elaboration of simulation the
atmospheric conditions (pressure, temperature, wind speed, wind
direction), the exhaust velocity of the combustion gases, chimney
height and the obstacles (buildings). Using the air quality monitoring
stations it is measured the concentrations of main pollutants (SO2,
NOx and PM). The pollutants were monitored over a period of 3
months, after that the average concentration are calculated, which is
used by the software. The concentrations are: 8.915 μg/m3 (NOx),
9.587 μg/m3 (SO2) and 42 μg/m3 (PM). A comparison of test data
with simulation results demonstrated that CFX was able to describe
the dispersion of the pollutant as well the concentration of this
pollutants in the atmosphere.
Abstract: It is necessary to predict a fatigue crack propagation
life for estimation of structural integrity. Because of an uncertainty
and a randomness of a structural behavior, it is also required to
analyze stochastic characteristics of the fatigue crack propagation life
at a specified fatigue crack size. The essential purpose of this study is to find the effect of load ratio
on probability distribution of the fatigue crack propagation life at a
specified grown crack size and to confirm the good probability
distribution in magnesium alloys under various fatigue load ratio
conditions. To investigate a stochastic crack growth behavior, fatigue
crack propagation experiments are performed in laboratory air under
several conditions of fatigue load ratio using AZ31. By Anderson-Darling test, a goodness-of-fit test for probability
distribution of the fatigue crack propagation life is performed. The
effect of load ratio on variability of fatigue crack propagation life is
also investigated.
Abstract: Psyllium gum alone and in combination with
sunflower oil was investigated as a possible alternative edible coating
for improvement of quality and shelf life of fresh-cut papaya.
Different concentrations including 0.5, 1 and 1.5 percent of psyllium
gum were used for coating of fresh-cut papaya. In some samples,
refined sunflower oil was used as a lipid component to increase the
effectiveness of coating in terms of water barrier properties. Soya
lecithin was used as an emulsifier in coatings containing oil.
Pretreatment with 1% calcium chloride was given to maintain the
firmness of fresh-cut papaya cubes. 1% psyllium gum coating was
found to yield better results. Further, addition of oil helped to
maintain the quality and acted as a barrier to water vapour, therefore,
minimizing the weight loss.
Abstract: Obesity and osteoporosis are the two diseases whose
increasing prevalence and high impact on the global morbidity and
mortality, during the two recent decades, have gained a status of
major health threats worldwide. Obesity purports to affect the bone
metabolism through complex mechanisms. Debated data on the
connection between the bone mineral density and fracture prevalence
in the obese patients are widely presented in literature. There is
evidence that the correlation of weight and fracture risk is sitespecific.
This study is aimed at determining the connection between
the bone mineral density (BMD) and trabecular bone score (TBS)
parameters in Ukrainian women suffering from obesity. We
examined 1025 40-89-year-old women, divided them into the groups
according to their body mass index: Group A included 360 women
with obesity whose BMI was ≥30 kg/m2, and Group B – 665 women
with no obesity and BMI of
Abstract: One of the crucial parameters of digital cryptographic
systems is the selection of the keys used and their distribution. The
randomness of the keys has a strong impact on the system’s security
strength being difficult to be predicted, guessed, reproduced, or
discovered by a cryptanalyst. Therefore, adequate key randomness
generation is still sought for the benefit of stronger cryptosystems.
This paper suggests an algorithm designed to generate and test
pseudo random number sequences intended for cryptographic
applications. This algorithm is based on mathematically manipulating
a publically agreed upon information between sender and receiver
over a public channel. This information is used as a seed for
performing some mathematical functions in order to generate a
sequence of pseudorandom numbers that will be used for
encryption/decryption purposes. This manipulation involves
permutations and substitutions that fulfill Shannon’s principle of
“confusion and diffusion”. ASCII code characters were utilized in the
generation process instead of using bit strings initially, which adds
more flexibility in testing different seed values. Finally, the obtained
results would indicate sound difficulty of guessing keys by attackers.
Abstract: A three-dimensional numerical model of
thermoelectric generator (TEG) modules attached to a large chimney
plate is proposed and solved numerically using a control volume based
finite difference formulation. The TEG module consists of a
thermoelectric generator, an elliptical pin-fin heat sink, and a cold
plate for water cooling. In the chimney, the temperature of flue gases is
450-650K. Although the TEG hot-side temperature and thus the
electric power output can be increased by inserting an elliptical pin-fin
heat sink into the chimney tunnel to increase the heat transfer area, the
pin fin heat sink would cause extra pumping power at the same time.
The main purpose of this study is to analyze the effects of geometrical
parameters on the electric power output and chimney pressure drop
characteristics. The effects of different operating conditions, including
various inlet velocities (Vin= 1, 3, 5 m/s), inlet temperatures (Tgas = 450,
550, 650K) and different fin height (0 to 150 mm) are discussed in
detail. The predicted numerical data for the power vs. current (P-I)
curve are in good agreement (within 11%) with the experimental data.
Abstract: The objective of this study was to evaluate the
physical and chemical characteristics of Serra da Estrela cheese and
compare these results with those of the sensory analysis. For the
study were taken six samples of Serra da Estrela cheese produced
with 6 different ecotypes of thistle in a dairy situated in Penalva do
Castelo. The chemical properties evaluated were moisture content,
protein, fat, ash, chloride and pH; the physical properties studied
were color and texture; and finally a sensory evaluation was
undertaken. The results showed moisture varying in the range 40-
48%, protein in the range 15-20%, fat between 41-45%, ash between
3.9-5.0% and chlorides varying from 1.2 to 3.0%. The pH varied
from 4.8 to 5.4. The textural properties revealed that the crust
hardness is relatively low (maximum 7.3 N), although greater than
flesh firmness (maximum 1.7 N), and also that these cheeses are in
fact soft paste type, with measurable stickiness and intense
adhesiveness. The color analysis showed that the crust is relatively
light (L* over 50), and with a predominant yellow coloration (b*
around 20 or over) although with a slight greenish tone (a* negative).
The results of the sensory analysis did not show great variability for
most of the attributes measured, although some differences were
found in attributes such as crust thickness, crust uniformity, and
creamy flesh.
Abstract: The aim of research was to define the relations
between volatile compounds, some parameters (pH, titratable acidity
(TA), total soluble solid (TSS), lactic acid bacteria count) and
consumer preference of commercial fermented milks. These relations
tend to be used for controlling and developing new fermented milk
product. Three leading commercial brands of fermented milks in
Thailand were evaluated by consumers (n=71) using hedonic scale
for four attributes (sweetness, sourness, flavour, and overall liking),
volatile compounds using headspace-solid phase microextraction
(HS-SPME) GC-MS, pH, TA, TSS and LAB count. Then the
relations were analyzed by principal component analysis (PCA). The
PCA data showed that all of four attributes liking scores were related
to each other. They were also related to TA, TSS and volatile
compounds. The related volatile compounds were mainly on
fermented produced compounds including acetic acid, furanmethanol,
furfural, octanoic acid and the volatiles known as artificial fruit
flavour (beta pinene, limonene, vanillin, and ethyl vanillin). These
compounds were provided the information about flavour addition in
commercial fermented milk in Thailand.
Abstract: Effect of biopesticide from wood vinegar and
extracted substances from 3 medicinal plants such as: non taai yak
(Stemona tuberosa Lour), boraphet (Tinospora crispa Mier) and
derris (Derris elliptica Roxb) were tested on the age five years of
pomelo. The selected pomelo was carried out for insects’ pest control
and its quality. The experimental site was located at farmer’s orchard
in Phichit Province, Thailand. This study was undertaken during the
drought season (December to March). The extracted from plants and
wood vinegar were evaluated in 6 treatments: 1) water as control; 2)
wood vinegar; 3) S. tuberosa Lour; 4) T. crispa Mier; 5) D. elliptica
Roxb; 6) mixed (wood vinegar + S. tuberosa Lour + T. crispa Mier +
D. elliptica Roxb). The experiment was RCB with 6 treatments and 3
replications per treatment. The results showed that T. crispa Mier was
the highest effectiveness for reduction population of thrips
(Scirtothrips dorsalis Hood) and citrus leaf miner (Phyllocnistis
citrella Stainton) at 14.10 and 15.37 respectively, followed by
treatment of mixed, D. elliptica Roxb, S. tuberosa Lour and wood
vinegar with significance different. Additionally, T. crispa Mier
promoted the high quality of harvested pomelo in term of thickness
of skin at 12.45 mm and S. tuberosa Lour gave the high quality of the
pomelo in term of firmness (276.5 kg/cm2) and brix (11.0%).
Abstract: The postharvest quality management of tomatoes is
important to limit the amount of losses that occur due to deterioration
between harvest and consumption. This study was undertaken to
investigate the effects of pre- and postharvest integrated agrotechnologies,
involving greenhouse microclimate and postharvest
storage conditions, on the postharvest quality attributes of four
tomato cultivars. Tomato fruit firmness, colour (hue angle (h°) and
L* value), pH and total soluble solids for the cultivars Bona,
Star 9037, Star 9009 and Zeal, grown in a fan-pad evaporativelycooled
and an open-ended naturally-ventilated tunnel, were harvested
at the mature-green stage. The tomatoes were stored for 28 days
under cold storage conditions, with a temperature of 13°C and RH of
85%, and under ambient air conditions, with a temperature of 23±
2°C and RH of 52± 4%. This study has provided information on the
effect of integrated pre-harvest and postharvest agro-technologies,
involving greenhouse microclimate and postharvest storage
environment on the postharvest quality attributes of four of the
tomato cultivars in South Africa. NVT-grown tomatoes retained
better textural qualities, but ripened faster by changing from green to
red faster, although these were reduced under cold storage conditions.
FPVT-grown tomatoes had lower firmness, but ripened slowly with
higher colour attributes. With cold storage conditions, the firmness of
FPVT-grown tomatoes was maintained. Cultivar Bona firmness and
colour qualities depreciated the fastest, but it had higher TSS content
and lower pH values. Star 9009 and Star 9037 presented better
quality, by retaining higher firmness and ripening slowly, but they
had the lowest TSS contents and high pH values, especially
Star 9037. Cold storage improved the firmness of tomato cultivars
with poor textural quality and faster colour changes.
Abstract: Brain functional networks based on resting-state EEG
data were compared between patients with mild Alzheimer’s disease
(mAD) and matched patients with amnestic subtype of mild cognitive
impairment (aMCI). We integrated the time–frequency cross mutual
information (TFCMI) method to estimate the EEG functional
connectivity between cortical regions and the network analysis based
on graph theory to further investigate the alterations of functional
networks in mAD compared with aMCI group. We aimed at
investigating the changes of network integrity, local clustering,
information processing efficiency, and fault tolerance in mAD brain
networks for different frequency bands based on several topological
properties, including degree, strength, clustering coefficient, shortest
path length, and efficiency. Results showed that the disruptions of
network integrity and reductions of network efficiency in mAD
characterized by lower degree, decreased clustering coefficient, higher
shortest path length, and reduced global and local efficiencies in the
delta, theta, beta2, and gamma bands were evident. The significant
changes in network organization can be used in assisting
discrimination of mAD from aMCI in clinical.
Abstract: The objective of the study was to select the survival of
probiotic strains when exposed to acidic and bile salts condition. Four
probiotic strains Lactobacillus casei subsp. rhamnosus TISTR 047,
Lactobacillus casei TISTR 1500, Lactobacillus acidophilus TISTR
1338 and Lactobacillus plantarum TISTR 1465 were cultured in
MRS broth and incubated at 35ºC for 15 hours before being inoculated
into acidic condition 5 M HCl, pH 2 for 2 hours and bile salt 0.3%,
pH 5.8 for 8 hour. The survived probiotics were counted in MRS agar.
Among four stains, Lactobacillus casei subsp. rhamnosus TISTR 047
was the highest tolerance specie. Lactobacillus casei subsp.
rhamnosus TISTR 047 reduced 6.74±0.07 log CFU/ml after growing
in acid and 5.52±0.05 log CFU/ml after growing in bile salt. Then,
double emulsion of microorganisms was chosen to encapsulate before
spray drying. Spray drying was done with the inlet temperature 170ºC
and outlet temperature 80ºC. The results showed that the survival of
encapsulated Lactobacillus casei subsp. rhamnosus TISTR 047 after
spray drying decreased from 9.63 ± 0.32 to 8.31 ± 0.11 log CFU/ml
comparing with non-encapsulated, 9.63 ± 0.32 to 4.06 ± 0.08 log
CFU/ml. Therefore, Lactobacillus casei subsp. rhamnosus TISTR 047
would be able to survive in gastrointestinal and spray drying condition.
Abstract: The fatigue crack growth is stochastic because of the fatigue behavior having an uncertainty and a randomness. Therefore, it is necessary to determine the probability distribution of a grown crack size at a specific fatigue crack propagation life for maintenance of structure as well as reliability estimation. The essential purpose of this study is to present the good probability distribution fit for the grown crack size at a specified fatigue life in a rolled magnesium alloy under different specimen thickness conditions. Fatigue crack propagation experiments are carried out in laboratory air under three conditions of specimen thickness using AZ31 to investigate a stochastic crack growth behavior. The goodness-of-fit test for probability distribution of a grown crack size under different specimen thickness conditions is performed by Anderson-Darling test. The effect of a specimen thickness on variability of a grown crack size is also investigated.
Abstract: The aim of this paper is image encryption using Genetic Algorithm (GA). The proposed encryption method consists of two phases. In modification phase, pixels locations are altered to reduce correlation among adjacent pixels. Then, pixels values are changed in the diffusion phase to encrypt the input image. Both phases are performed by GA with binary chromosomes. For modification phase, these binary patterns are generated by Local Binary Pattern (LBP) operator while for diffusion phase binary chromosomes are obtained by Bit Plane Slicing (BPS). Initial population in GA includes rows and columns of the input image. Instead of subjective selection of parents from this initial population, a random generator with predefined key is utilized. It is necessary to decrypt the coded image and reconstruct the initial input image. Fitness function is defined as average of transition from 0 to 1 in LBP image and histogram uniformity in modification and diffusion phases, respectively. Randomness of the encrypted image is measured by entropy, correlation coefficients and histogram analysis. Experimental results show that the proposed method is fast enough and can be used effectively for image encryption.
Abstract: Proximate composition (moisture, protein, total fat, and total ash) and textural characteristics (hardness, adhesiveness, springiness, cohesiveness, chewiness and firmness and work of shear) of cooked sausages formulated from mechanically deboned chicken meat (MDCM) with addition of chicken offal (heart, gizzard or liver) were investigated. Chicken offal replaced equal weight (15 kg) of MDCM in standard sausage formulation. Regarding proximate composition sausage with heart addition was significantly (P
Abstract: In this study, the in vitro anticholinesterase activity of
the volatile oils of both O. basilicum and O. africanum was
investigated and both samples showed significant activity. The major
constituents of the two oils were isolated using several column
chromatographies. Linalool, 1,8-cineol and eugenol were isolated
from the volatile oil of O. basilicum and camphor was isolated from
the volatile oil of O. africanum. The anticholinesterase activities of
the isolated compounds were also evaluated where 1,8-cineol showed
the highest inhibitory activity followed by camphor. To confirm these
activities, learning and memory enhancing effects were tested in
mice. Memory impairment was induced by scopolamine, a
cholinergic muscarinic receptor antagonist. Anti-amnesic effects of
both volatile oils and their terpenoids were investigated by the
passive avoidance task in mice. We also examined their effects on
brain acetylcholinesterase activity. Results showed that scopolamineinduced
cognitive dysfunction was significantly attenuated by
administration of the volatile oils and their terpenoids, eugenol and
camphor, in the passive avoidance task and inhibited brain
acetylcholinesterase activity. These results suggest that O. basilicum
and O. africanum volatile oils can be good candidates for further
studies on Alzheimer’s disease via their acetylcholinesterase
inhibitory actions.
Abstract: In this paper, modeling of an acoustic enclosed
vehicle cabin has been carried out by using boundary element
method. Also, the second purpose of this study is analyzing of linear
wave equation in an acoustic field. The resultants of this modeling
consist of natural frequencies that have been compared with
resultants derived from finite element method. By using numerical
method (boundary element method) and after solution of wave
equation inside an acoustic enclosed cabin, this method has been
progressed to simulate noise inside a simple vehicle cabin.