Abstract: In this paper, a class of predator-prey-chain model with harvesting terms are studied. By using Mawhin-s continuation theorem of coincidence degree theory and some skills of inequalities, some sufficient conditions are established for the existence of eight positive periodic solutions. Finally, an example is presented to illustrate the feasibility and effectiveness of the results.
Abstract: High strength concrete has been used in situations
where it may be exposed to elevated temperatures. Numerous authors
have shown the significant contribution of polypropylene fiber to the
spalling resistance of high strength concrete.
When cement-based composite that reinforced by polypropylene
fibers heated up to 170 °C, polypropylene fibers readily melt and
volatilize, creating additional porosity and small channels in to the
matrix that cause the poor structure and low strength.
This investigation develops on the mechanical properties of mortar
incorporating polypropylene fibers exposed to high temperature.
Also effects of different pozzolans on strength behaviour of samples
at elevated temperature have been studied.
To reach this purpose, the specimens were produced by partial
replacement of cement with finely ground glass, silica fume and rice
husk ash as high reactive pozzolans. The amount of this replacement
was 10% by weight of cement to find the effects of pozzolans as a
partial replacement of cement on the mechanical properties of
mortars. In this way, lots of mixtures with 0%, 0.5%, 1% and 1.5% of
polypropylene fibers were cast and tested for compressive and
flexural strength, accordance to ASTM standard. After that
specimens being heated to temperatures of 300, 600 °C, respectively,
the mechanical properties of heated samples were tested.
Mechanical tests showed significant reduction in compressive
strength which could be due to polypropylene fiber melting. Also
pozzolans improve the mechanical properties of sampels.
Abstract: Ultrastructure of duodenum mucosa of irradiated rat
was studied versus dose rate of irradiation following exposure to
gamma rays from 60-Cobalt source. The animals were whole body
irradiated at two dose rates (1 Gy.mn-1 and 1 Gy.h-1) and three total
doses (1, 2 or 4 Gy) for each dose rate. 24 or 48 h after irradiation,
their small intestine was removed and samples of duodenum were
processed for observations under a transmission electron microscopy.
Samples of duodenum mucosa of control rats were processed in the
same way. For the lower dose rate of 1 Gy.h-1, main lesions
characteristic of apoptosis were detected within irradiated enterocytes
at a total dose of 2 Gy and 24 h after exposure. Necrosis was noted in
the samples, 48 h after exposition. For the higher dose rate of 1
Gy.mn-1, fewer changes were detected at all total doses 24 or 48 h
irradiation. Thus, it was shown that the appearance of radiationinduced
alterations varies not only with increasing total dose and
post-irradiation time but especially with decreasing dose rate.
Abstract: Early detection of dementia by testing the spatial
memory can be applied using a virtual environment. This paper
presents guidelines on how to design a virtual environment
specifically for elderly in early detection of dementia. The specific
design needs to be considered because the effectiveness of the
technology relies on the ability of the end user to use it. The primary
goal of these guidelines is to promote accessibility. Based on these
guidelines, a virtual simulation was developed and evaluated. The
results on usability of acceptance and satisfaction that are tested on
young (control group) and elderly participants indicate that these
guidelines are reliable and useful for use with elderly people.
Abstract: Sunflower stalks were analysed for chemical
compositions: pentosan 15.84%, holocellulose 70.69%,
alphacellulose 45.74%, glucose 27.10% and xylose 7.69% based on
dry weight of 100-g raw material. The most optimum condition for
steam explosion pretreatment was as follows. Sunflower stalks were
cut into small pieces and soaked in 0.02 M H2SO4 for overnight.
After that, they were steam exploded at 207 C and 21 kg/cm2 for 3
minutes to fractionate cellulose, hemicellulose and lignin. The
resulting hydrolysate, containing hemicellulose, and cellulose pulp
contained xylose sugar at 2.53% and 7.00%, respectively.The pulp
was further subjected to enzymatic saccharification at 50 C, pH 4.8 citrate buffer) with pulp/buffer 6% (w/w)and Celluclast 1.5L/pulp
2.67% (w/w) to obtain single glucose with maximum yield 11.97%.
After fixed-bed fermentation under optimum condition using
conventional yeast mixtures to produce bioethanol, it indicated
maximum ethanol yield of 0.028 g/100 g sunflower stalk.
Abstract: This paper describes a new approach of classification
using genetic programming. The proposed technique consists of
genetically coevolving a population of non-linear transformations on
the input data to be classified, and map them to a new space with a
reduced dimension, in order to get a maximum inter-classes
discrimination. The classification of new samples is then performed
on the transformed data, and so become much easier. Contrary to the
existing GP-classification techniques, the proposed one use a
dynamic repartition of the transformed data in separated intervals, the
efficacy of a given intervals repartition is handled by the fitness
criterion, with a maximum classes discrimination. Experiments were
first performed using the Fisher-s Iris dataset, and then, the KDD-99
Cup dataset was used to study the intrusion detection and
classification problem. Obtained results demonstrate that the
proposed genetic approach outperform the existing GP-classification
methods [1],[2] and [3], and give a very accepted results compared to
other existing techniques proposed in [4],[5],[6],[7] and [8].
Abstract: The modified Claus process is commonly used in oil
refining and gas processing to recover sulfur and destroy
contaminants formed in upstream processing. A Claus furnace feed
containing a relatively low concentration of H2S may be incapable of
producing a stable flame. Also, incomplete combustion of
hydrocarbons in the feed can lead to deterioration of the catalyst in
the reactors due to soot or carbon deposition. Therefore, special
consideration is necessary to achieve the appropriate overall sulfur
recovery. In this paper, some configurations available to treat lean
acid gas streams are described and the most appropriate ones are
studied to overcome low H2S concentration problems. As a result,
overall sulfur recovery is investigated for feed preheating and hot gas
configurations.
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.
Abstract: This paper presents the optimal controller design of
the generator control unit in the aircraft power system. The adaptive
tabu search technique is applied to tune the controller parameters
until the best terminal output voltage of generator is achieved. The
output response from the system with the controllers designed by the
proposed technique is compared with those from the conventional
method. The transient simulations using the commercial software
package show that the controllers designed from the adaptive tabu
search algorithm can provide the better output performance compared
with the result from the classical method. The proposed design
technique is very flexible and useful for electrical aircraft engineers.
Abstract: Nowadays predicting political risk level of country
has become a critical issue for investors who intend to achieve
accurate information concerning stability of the business
environments. Since, most of the times investors are layman and
nonprofessional IT personnel; this paper aims to propose a
framework named GECR in order to help nonexpert persons to
discover political risk stability across time based on the political
news and events.
To achieve this goal, the Bayesian Networks approach was
utilized for 186 political news of Pakistan as sample dataset.
Bayesian Networks as an artificial intelligence approach has been
employed in presented framework, since this is a powerful technique
that can be applied to model uncertain domains. The results showed
that our framework along with Bayesian Networks as decision
support tool, predicted the political risk level with a high degree of
accuracy.
Abstract: In this paper we introduce new data oriented modeling
of uniform random variable well-matched with computing systems. Due to this conformity with current computers structure, this modeling will be efficiently used in statistical inference.
Abstract: A lot of recent research have spoken on the relation
between the increase of the homocysteinemia and some kinds of
cancer . For that, our study was based on the research of a possible
relation between the increase of the concentration of this amino-acid
in the plasma and the appearance of the disease of the Acute
Lymphoblastic Leukaemia in a part of Algerian children with Berber
origin in the East of Algeria . The study has done on 47 ill persons
with an average age of (09±06 ) years , with whom the disease has
diagnosed by blood and marrow examination in the hospital of blood
diseases in the CHU of Batna, and on 194 healthy witnesses of the
same age. The two groups were benefited by a dosage of the
concentration of the homocysteine vitamin B9 ,vitamin B12 , and
also of the study of special polymorphisms of indispensable enzymes
in the metabolism of this acid , and that by the use of the method (
Light cycler ) Real time PCR , on the following enzymes : MS (
C2756G ), MSR ( A66G ) ,MTHFR1 ( C677T ) and MTHFR2
(A1298C). The obtained results have revealed that the rate of the
homozygote muted genotype is the less frequent in the two groups ,
and that exist at list one genotype of each enzyme in the ill group and
in which the percentage exceed with remarkable way the same
genotype in the healthy group and we notice specially the muted
genotype GG of -the methionine synthetase-and the form TT of the
enzyme – methyline tetra hydrofolate reductase – We notice the
existence of considerable number of genotypes in the ill group lied
with characteristic increase of this Amino-acid ,and that for the
reduction of the biologic activity of these enzymes which become
inefficient in the transfer of the homocysteine into the methionine
and cause the diminution of the biologic activity of these enzymes
and with consequence the reduction of the percentage of methylic
radicals in the DNA of studied genes and that lead to the increase of
the activity and the capacity of transcription , and it-s so probably
that this last one is one of the factors of this disease especially if we
know that the specific check-up of vitamins is normal and similar in
the two groups , which ovoid the hypothesis of the reduction of
vitamins . We notice also that the heterozygote genotype is the less in
the sick category except the MTHFR2. Wild genotype is more
frequent in the witness group except MSR. Even these results are
partials; they open a new way in the genetic diagnosis of this
malicious disease which allow a precocious diagnosis and the use of
an effective and appropriated treatment in the same time.
Abstract: Plackett-Burman statistical screening of media
constituents and operational conditions for extracellular lipase
production from isolate Trichoderma viride has been carried out in
submerged fermentation. This statistical design is used in the early
stages of experimentation to screen out unimportant factors from a
large number of possible factors. This design involves screening of
up to 'n-1' variables in just 'n' number of experiments. Regression
coefficients and t-values were calculated by subjecting the
experimental data to statistical analysis using Minitab version 15.
The effects of nine process variables were studied in twelve
experimental trials. Maximum lipase activity of 7.83 μmol /ml /min
was obtained in the 6th trail. Pareto chart illustrates the order of
significance of the variables affecting the lipase production. The
present study concludes that the most significant variables affecting
lipase production were found to be palm oil, yeast extract, K2HPO4,
MgSO4 and CaCl2.
Abstract: The effectiveness of consuming a nutrient fortified oat drink on iron, zinc, vitamin A and vitamin C status was assessed among a cohort of school-aged Filipino children. Ultimate study implementation permitted only a within-subject comparison of change in nutritional status after four months of consuming a nutrient fortified oat drink. Thirty-eight anemic children (5-8 years) consumed an oat drink fortified with iron as NaFeEDTA, zinc, vitamin A and vitamin C for 120 days. Height, weight, serum nutrient levels, anemia status and dietary intake were assessed pre and post intervention. Thirty-four anemic children completed the intervention. After 4 months of intervention, prevalence of anemia decreased by 68% and significant improvements in iron and vitamin A status were observed. Results demonstrate the effectiveness of the fortified oat drink in alleviating anemia in young children and highlight the value of fortification programs
Abstract: Needs of an efficient information retrieval in recent
years in increased more then ever because of the frequent use of
digital information in our life. We see a lot of work in the area of
textual information but in multimedia information, we cannot find
much progress. In text based information, new technology of data
mining and data marts are now in working that were started from the
basic concept of database some where in 1960.
In image search and especially in image identification,
computerized system at very initial stages. Even in the area of image
search we cannot see much progress as in the case of text based
search techniques. One main reason for this is the wide spread roots
of image search where many area like artificial intelligence,
statistics, image processing, pattern recognition play their role. Even
human psychology and perception and cultural diversity also have
their share for the design of a good and efficient image recognition
and retrieval system.
A new object based search technique is presented in this paper
where object in the image are identified on the basis of their
geometrical shapes and other features like color and texture where
object-co-relation augments this search process.
To be more focused on objects identification, simple images are
selected for the work to reduce the role of segmentation in overall
process however same technique can also be applied for other
images.
Abstract: This paper describes the crashworthiness assessment and improvement of tlting train made of sandwich composites. The crashworhiness assessment of tilting train was conducted according to four collision scenarios of the Korean railway safety law. Collision analysis was carried out using explicit finite element analysis code LS-DYNA 3D. The finite element model consists of 3-D finite element model and 1-D equivalent model to save the finite element modeling and calculation time. It found that the crashworthiness analysis results were satisfied with the performance requirements except the crash scenario-2. In order to meet the crashworthiness requirements for crash scenario-2, the stiffness reinforcement for the laminate composite cover and metal frames of cabmask structure were proposed. Consequentially, it has satisfied the requirement for crash scenario-2.
Abstract: In a competitive energy market, system reliability
should be maintained at all times. Power system operation being of
online in nature, the energy balance requirements must be satisfied to
ensure reliable operation the system. To achieve this, information
regarding the expected status of the system, the scheduled
transactions and the relevant inputs necessary to make either a
transaction contract or a transmission contract operational, have to be
made available in real time. The real time procedure proposed,
facilitates this. This paper proposes a quadratic curve learning
procedure, which enables a generator-s contribution to the retailer
demand, power loss of transaction in a line at the retail end and its
associated losses for an oncoming operating scenario to be predicted.
Matlab program was used to test in on a 24-bus IEE Reliability Test
System, and the results are found to be acceptable.
Abstract: A design flow of multi-standard down-conversion
CMOS mixers for three modern standards: Global System Mobile,
Digital Enhanced Cordless Telephone and Universal Mobile
Telecommunication Systems is presented. Three active mixer-s
structures are studied. The first is based on the Gilbert cell which
gives a tolerable noise figure and linearity with a low conversion
gain. The second and third structures use the current bleeding and
charge injection techniques in order to increase the conversion gain.
An improvement of about 2 dB of the conversion gain is achieved
without a considerable degradation of the other characteristics. The
models used for noise figure, conversion gain and IIP3 used are
studied. This study describes the nature of trade-offs inherent in such
structures and gives insights that help in identifying which structure
is better for given conditions.
Abstract: Generation system reliability assessment is an
important task which can be performed using deterministic or
probabilistic techniques. The probabilistic approaches have
significant advantages over the deterministic methods. However,
more complicated modeling is required by the probabilistic
approaches. Power generation model is a basic requirement for this
assessment. One form of the generation models is the well known
capacity outage probability table (COPT). Different analytical
techniques have been used to construct the COPT. These approaches
require considerable mathematical modeling of the generating units.
The unit-s models are combined to build the COPT which will add
more burdens on the process of creating the COPT. Decimal to
Binary Conversion (DBC) technique is widely and commonly applied
in electronic systems and computing This paper proposes a novel
utilization of the DBC to create the COPT without engaging in
analytical modeling or time consuming simulations. The simple
binary representation , “0 " and “1 " is used to model the states o f
generating units. The proposed technique is proven to be an effective
approach to build the generation model.
Abstract: An exploratory computational investigation using
RANS & URANS was carried out to understand the aerodynamics
around an isolatedsingle rotating wheel with decreasing ground
proximity. The wheel was initially modeled in free air conditions,
then with decreasing ground proximity and increased yaw angle with
rotational speeds. Three speeds of rotation were applied to the wheel
so that the effect of different angular velocities can be investigated. In
addition to rotation, three different yaw angles were applied to the
rotating wheel in order to understand how these two variables
combined affect the aerodynamic flow field around the wheel.