Abstract: The current study has investigated the ageing
phenomena of silica optical fibres in relation to water activity which might be accelerated when exposed to a supplementary energy, such as microwaves. A controlled stress by winding fibres onto accurate
diameter mandrel was applied. Taking into account that normally a
decrease in fibre strength is induced in time by chemical action of water, the effects of cumulative reagents such as: water, applied stress and supplementary energy (microwave) in some cases acted in
the opposite manner. The microwave effect as a structural relaxation
catalyst appears unexpected, even if the overall gain in fibre strength is not high, but the stress corrosion factor revealed significant
increase in certain simulation conditions.
Abstract: A slant weighted Toeplitz operator Aφ is an operator
on L2(β) defined as Aφ = WMφ where Mφ is the weighted
multiplication operator and W is an operator on L2(β) given by
We2n = βn
β2n
en, {en}n∈Z being the orthonormal basis. In this paper,
we generalise Aφ to the k-th order slant weighted Toeplitz operator
Uφ and study its properties.
Abstract: A greenhouse experiment was conducted to investigate the effects of different types of nutrients induced salinity on the growth, membrane permeability, nitrate reductase activity, proline content and macronutrient concentrations of tomato plants. The plants were subjected to six different treatments: 1 (control) containing basic solution, 2 basic solution+40mM of NaCl, 3 basic solution+40 mM of KNO3, 4 basic solution+20 mM of Ca(NO3)2.4H2O, 5 basic solution+20 mM of Mg(NO3)2.6H2O and 6 basic solution+20 mM of KNO3+5 mM of Ca(NO3)2.4H2O+5 mM of Mg(NO3)2.6H2O. Membrane permeability was increased significantly only with addition of NaCl, and then decreased to its lower level with addition of Ca(NO3)2.4H2O and Mg(NO3)2.6H2O. Proline accumulation were followed the same trend of results when they had been exposed to NaCl salinity. Nitrate reductase activity (NRA) was significantly affected by addition of different types of nutrient induced salinity.
Abstract: Utilization of diverse germplasm is needed to enhance
the genetic diversity of cultivars. The objective of this study was to
evaluate the genetic relationships of 98 alfalfa germplasm accessions
using morphological traits and SSR markers. From the 98 tested
populations, 81 were locals originating in Europe, 17 were introduced
from USA, Australia, New Zealand and Canada. Three primers
generated 67 polymorphic bands. The average polymorphic
information content (PIC) was very high (> 0.90) over all three used
primer combinations. Cluster analysis using Unweighted Pair Group
Method with Arithmetic Means (UPGMA) and Jaccard´s coefficient
grouped the accessions into 2 major clusters with 4 sub-clusters with
no correlation between genetic and morphological diversity. The SSR
analysis clearly indicated that even with three polymorphic primers,
reliable estimation of genetic diversity could be obtained.
Abstract: Limited infrastructure development on peats and
organic soils is a serious geotechnical issues common to many
countries of the world especially Malaysia which distributed 1.5 mill
ha of those problematic soil. These soils have high water content and
organic content which exhibit different mechanical properties and
may also change chemically and biologically with time. Constructing
structures on peaty ground involves the risk of ground failure and
extreme settlement. Nowdays, much efforts need to be done in
making peatlands usable for construction due to increased landuse.
Deep mixing method employing cement as binders, is generally used
as measure again peaty/ organic ground failure problem. Where the
technique is widely adopted because it can improved ground
considerably in a short period of time. An understanding of
geotechnical properties as shear strength, stiffness and compressibility
behavior of these soils was requires before continues construction on
it. Therefore, 1- 1.5 meter peat soil sample from states of Johor and
an organic soil from Melaka, Malaysia were investigated. Cement
were added to the soil in the pre-mixing stage with water cement ratio
at range 3.5,7,14,140 for peats and 5,10,30 for organic soils,
essentially to modify the original soil textures and properties. The
mixtures which in slurry form will pour to polyvinyl chloride (pvc)
tube and cured at room temperature 250C for 7,14 and 28 days.
Laboratory experiments were conducted including unconfined
compressive strength and bender element , to monitor the improved
strength and stiffness of the 'stabilised mixed soils'. In between,
scanning electron miscroscopic (SEM) were observations to
investigate changes in microstructures of stabilised soils and to
evaluated hardening effect of a peat and organic soils stabilised
cement. This preliminary effort indicated that pre-mixing peat and
organic soils contributes in gaining soil strength while help the
engineers to establish a new method for those problematic ground
improvement in further practical and long term applications.
Abstract: A novel method of individual level adaptive mutation rate control called the rank-scaled mutation rate for genetic algorithms is introduced. The rank-scaled mutation rate controlled genetic algorithm varies the mutation parameters based on the rank of each individual within the population. Thereby the distribution of the fitness of the papulation is taken into consideration in forming the new mutation rates. The best fit mutate at the lowest rate and the least fit mutate at the highest rate. The complexity of the algorithm is of the order of an individual adaptation scheme and is lower than that of a self-adaptation scheme. The proposed algorithm is tested on two common problems, namely, numerical optimization of a function and the traveling salesman problem. The results show that the proposed algorithm outperforms both the fixed and deterministic mutation rate schemes. It is best suited for problems with several local optimum solutions without a high demand for excessive mutation rates.
Abstract: The IFS is a scheme for describing and manipulating complex fractal attractors using simple mathematical models. More precisely, the most popular “fractal –based" algorithms for both representation and compression of computer images have involved some implementation of the method of Iterated Function Systems (IFS) on complete metric spaces. In this paper a new generalized space called Multi-Fuzzy Fractal Space was constructed. On these spases a distance function is defined, and its completeness is proved. The completeness property of this space ensures the existence of a fixed-point theorem for the family of continuous mappings. This theorem is the fundamental result on which the IFS methods are based and the fractals are built. The defined mappings are proved to satisfy some generalizations of the contraction condition.
Abstract: Evolvable hardware (EHW) is a developing field that
applies evolutionary algorithm (EA) to automatically design circuits,
antennas, robot controllers etc. A lot of research has been done in this
area and several different EAs have been introduced to tackle
numerous problems, as scalability, evolvability etc. However every
time a specific EA is chosen for solving a particular task, all its
components, such as population size, initialization, selection
mechanism, mutation rate, and genetic operators, should be selected
in order to achieve the best results. In the last three decade the
selection of the right parameters for the EA-s components for solving
different “test-problems" has been investigated. In this paper the
behaviour of mutation rate for designing logic circuits, which has not
been done before, has been deeply analyzed. The mutation rate for an
EHW system modifies the number of inputs of each logic gates, the
functionality (for example from AND to NOR) and the connectivity
between logic gates. The behaviour of the mutation has been
analyzed based on the number of generations, genotype redundancy
and number of logic gates for the evolved circuits. The experimental
results found provide the behaviour of the mutation rate during
evolution for the design and optimization of simple logic circuits.
The experimental results propose the best mutation rate to be used for
designing combinational logic circuits. The research presented is
particular important for those who would like to implement a
dynamic mutation rate inside the evolutionary algorithm for evolving
digital circuits. The researches on the mutation rate during the last 40
years are also summarized.
Abstract: An efficient transient flow simulation for gas
pipelines and networks is presented. The proposed transient flow
simulation is based on the transfer function models and MATLABSimulink.
The equivalent transfer functions of the nonlinear
governing equations are derived for different types of the boundary
conditions. Next, a MATLAB-Simulink library is developed and
proposed considering any boundary condition type. To verify the
accuracy and the computational efficiency of the proposed
simulation, the results obtained are compared with those of the
conventional finite difference schemes (such as TVD, method of
lines, and other finite difference implicit and explicit schemes). The
effects of the flow inertia and the pipeline inclination are
incorporated in this simulation. It is shown that the proposed
simulation has a sufficient accuracy and it is computationally more
efficient than the other methods.
Abstract: Monitoring of microbial flora in aquacultured sea bream, in relation to the physicochemical parameters of the rearing seawater, ended to a model describing the influence of the last to the quality of the fisheries. Fishes were sampled during eight months from four aqua farms in Western Greece and analyzed for psychrotrophic, H2S producing bacteria, Salmonella sp., heterotrophic plate count (PCA), with simultaneous physical evaluation. Temperature, dissolved oxygen, pH, conductivity, TDS, salinity, NO3 - and NH4 + ions were recorded. Temperature, dissolved oxygen and conductivity were correlated, respectively, to PCA, Pseudomonas sp. and Shewanella sp. counts. These parameters were the inputs of the model, which was driving, as outputs, to the prediction of PCA, Vibrio sp., Pseudomonas sp. and Shewanella sp. counts, and fish microbiological quality. The present study provides, for the first time, a ready-to-use predictive model of fisheries hygiene, leading to an effective management system for the optimization of aquaculture fisheries quality.
Abstract: The problem of generation expansion planning (GEP)
has been extensively studied for many years. This paper presents
three topics in GEP as follow: statistical model, models for
generation expansion, and expansion problem. In the topic of
statistical model, the main stages of the statistical modeling are
briefly explained. Some works on models for GEP are reviewed in
the topic of models for generation expansion. Finally for the topic of
expansion problem, the major issues in the development of a longterm
expansion plan are summarized.
Abstract: Most of the well known methods for generating
Gaussian variables require at least one standard uniform distributed
value, for each Gaussian variable generated. The length of the
random number generator therefore, limits the number of
independent Gaussian distributed variables that can be generated
meanwhile the statistical solution of complex systems requires a
large number of random numbers for their statistical analysis. We
propose an alternative simple method of generating almost infinite
number of Gaussian distributed variables using a limited number of
standard uniform distributed random numbers.
Abstract: The business strategy of any company wanting to be
competitive on the market should be designed around the concept of
intangibles, with an increasingly decisive role in knowledge transfer
of the biggest corporations. Advancing the research in these areas,
this study integrates the two approaches, emphasizing the
relationships between the components of intellectual capital and
corporate social responsibility. The three dimensions of intellectual
capital in terms of sustainability requirements are debated. The paper
introduces the concept of sustainable intellectual capital and debates
it within an assessment model designed on the base of key
performance indicators. The results refer to the assessment of
possible ways for including the information on intellectual capital
and corporate responsibility within the corporate strategy. The
conclusions enhance the need for companies to be ready to support
the integration of this type of information the knowledge transfer
process, in order to develop competitive advantage on the market.
Abstract: This paper proposes a zero-voltage transition (ZVT) PWM synchronous buck converter, which is designed to operate at low output voltage and high efficiency typically required for portable systems. To make the DC-DC converter efficient at lower voltage, synchronous converter is an obvious choice because of lower conduction loss in the diode. The high-side MOSFET is dominated by the switching losses and it is eliminated by the soft switching technique. Additionally, the resonant auxiliary circuit designed is also devoid of the switching losses. The suggested procedure ensures an efficient converter. Theoretical analysis, computer simulation, and experimental results are presented to explain the proposed schemes.
Abstract: Mushrooms are a group of fleshy macroscopic fungi.
They have been valued throughout the world as both edible and
medicine. They are highly nutritious with good amount of quality
proteins, vitamins and minerals. An edible mushroom, Calocybe
indica was selected to validate its nutritional and medicinal
properties. Since tissue damage in hyperglycemia has been related to
oxidative stress, we evaluated the enzymatic and non-enzymatic
antioxidant status in the serum, liver and kidney since they are the
target organs in diabetic complications. From the results, increased
oxidative stress and decreased antioxidants might be related to the
causation of diabetes mellitus. The treatment in the diabetic rats with
the Calocybe indica showed an increase in the antioxidant system
and decrease in the production of free radicals. The mushrooms
which contain antioxidant phytochemicals has potential free radical
scavenging capacity and hence can induce the antioxidant system in
the body significantly reduces the generated free radicals thereby
maintaining the normal levels of the antioxidants
Abstract: Procurement is an important component in the field of
operating resource management and e-procurement is the golden key
to optimizing the supply chains system. Global firms are optimistic
on the level of savings that can be achieved through full
implementation of e-procurement strategies. E-procurement is an
Internet-based business process for obtaining materials and services
and managing their inflow into the organization. In this paper, the
subjects of supply chains and e-procurement and its benefits to
organizations have been studied. Also, e-procurement in construction
and its drivers and barriers have been discussed and a framework of
supplier selection in an e-procurement environment has been
demonstrated. This paper also has addressed critical success factors
in adopting e-procurement in supply chains.
Abstract: In this paper, based on flume experimental data, the velocity distribution in open channel flows is re-investigated. From the analysis, it is proposed that the wake layer in outer region may be divided into two regions, the relatively weak outer region and the relatively strong outer region. Combining the log law for inner region and the parabolic law for relatively strong outer region, an explicit equation for mean velocity distribution of steady and uniform turbulent flow through straight open channels is proposed and verified with the experimental data. It is found that the sediment concentration has significant effect on velocity distribution in the relatively weak outer region.
Abstract: This paper presents a practical scheme that can be used for allocating the transmission loss to generators and loads. In this scheme first the share of a generator or load on the current through a branch is determined using Z-bus modified matrix. Then the current components are decomposed and the branch loss allocation is obtained. A motivation of proposed scheme is to improve the results of Z-bus method and to reach more fair allocation. The proposed scheme has been implemented and tested on several networks. To achieve practical and applicable results, the proposed scheme is simulated and compared on the transmission network (400kv) of Khorasan region in Iran and the 14-bus standard IEEE network. The results show that the proposed scheme is comprehensive and fair to allocating the energy losses of a power market to its participants.
Abstract: Hysteresis phenomenon has been observed in the
operations of both horizontal-axis and vertical-axis wind turbines
(HAWTs and VAWTs). In this study, wind tunnel experiments were
applied to investigate the characters of hysteresis phenomena between
the angular speed and the external resistance of electrical loading
during the operation of a Darrieus type VAWT. Data of output voltage,
output current, angular speed of wind turbine under different wind
speeds are measured and analyzed. Results show that the range of
external resistance changes with the wind speed. The range decreases
as the wind speed increases following an exponential decay form.
Experiments also indicate that the maximum output power of wind
turbines is always inside the range where hysteresis happened. These
results provide an important reference to the design of output control
system of wind turbines.
Abstract: This study was carried out experimentally and analytically about the performance of solar cell panel system for operating the pump coupled by dc-motor. The solar cell panel with total area 1.9848 m2 consists of three modules of 80 Wp each. The small centrifugal pump powered by dc-motor is operated to lift water from 1m to 7m heads in sequence and gives the amount of water pumped over the whole day from 08.00 to 16.00 h are 11988, 10851, 8874, 7695, 5760, 3600, 2340 L/d respectively. The hourly global solar radiation during the day is an average of 506 W/m2. This study also presents the I-V characteristics of the panel at global radiations 200, 400, 600, 800 and 1000 W/m2 matched with the operation of the pump at the above lifting heads. It proves that the only solar radiations 800 and 1000 W/m2 could provide lifting head from 1m to 7m. The analysis shows the best efficiency point of the performance of solar cell panel system occurs at the pumping head 2.89 m.