Abstract: A piston cylinder based high pressure differential
thermal analyzer system is developed to investigate phase
transformations, melting, glass transitions, crystallization behavior of
inorganic materials, glassy systems etc., at ambient to 4 GPa and at
room temperature to 1073 K. The pressure is calibrated by the phase
transition of bismuth and ytterbium and temperature is calibrated
by using thermocouple data chart. The system developed is
calibrated using benzoic acid, ammonium nitrate and it has a
pressure and temperature control of ± 8.9 x 10 -4 GPa , ± 2 K
respectively. The phase transition of Asx Te100-x chalcogenides,
ferrous oxide and strontium boride are studied using the
indigenously developed system.
Abstract: Monitoring of ecological systems is one of the major
issues in ecosystem research. The concepts and methodology of
mathematical systems theory provide useful tools to face this
problem. In many cases, state monitoring of a complex ecological
system consists in observation (measurement) of certain state
variables, and the whole state process has to be determined from the
observed data. The solution proposed in the paper is the design of an
observer system, which makes it possible to approximately recover
the state process from its partial observation. The method is
illustrated with a trophic chain of resource – producer – primary
consumer type and a numerical example is also presented.
Abstract: Quality of 2D and 3D cross-sectional images produce
by Computed Tomography primarily depend upon the degree of
precision of primary and secondary X-Ray intensity detection.
Traditional method of primary intensity detection is apt to errors.
Recently the X-Ray intensity measurement system along with smart
X-Ray sensors is developed by our group which is able to detect
primary X-Ray intensity unerringly. In this study a new smart X-Ray
sensor is developed using Light-to-Frequency converter TSL230
from Texas Instruments which has numerous advantages in terms of
noiseless data acquisition and transmission. TSL230 construction is
based on a silicon photodiode which converts incoming X-Ray
radiation into the proportional current signal. A current to frequency
converter is attached to this photodiode on a single monolithic CMOS
integrated circuit which provides proportional frequency count to
incoming current signal in the form of the pulse train. The frequency
count is delivered to the center of PICDEM FS USB board with
PIC18F4550 microcontroller mounted on it. With highly compact
electronic hardware, this Demo Board efficiently read the smart
sensor output data. The frequency output approaches overcome
nonlinear behavior of sensors with analog output thus un-attenuated
X-Ray intensities could be measured precisely and better
normalization could be acquired in order to attain high resolution.
Abstract: This paper presents a heuristic to solve large size 0-1 Multi constrained Knapsack problem (01MKP) which is NP-hard. Many researchers are used heuristic operator to identify the redundant constraints of Linear Programming Problem before applying the regular procedure to solve it. We use the intercept matrix to identify the zero valued variables of 01MKP which is known as redundant variables. In this heuristic, first the dominance property of the intercept matrix of constraints is exploited to reduce the search space to find the optimal or near optimal solutions of 01MKP, second, we improve the solution by using the pseudo-utility ratio based on surrogate constraint of 01MKP. This heuristic is tested for benchmark problems of sizes upto 2500, taken from literature and the results are compared with optimum solutions. Space and computational complexity of solving 01MKP using this approach are also presented. The encouraging results especially for relatively large size test problems indicate that this heuristic can successfully be used for finding good solutions for highly constrained NP-hard problems.
Abstract: Concrete performance is strongly affected by the
particle packing degree since it determines the distribution of the
cementitious component and the interaction of mineral particles. By
using packing theory designers will be able to select optimal
aggregate materials for preparing concrete with low cement content,
which is beneficial from the point of cost. Optimum particle packing
implies minimizing porosity and thereby reducing the amount of
cement paste needed to fill the voids between the aggregate particles,
taking also the rheology of the concrete into consideration. For
reaching good fluidity superplasticizers are required. The results from
pilot tests at Luleå University of Technology (LTU) show various
forms of the proposed theoretical models, and the empirical approach
taken in the study seems to provide a safer basis for developing new,
improved packing models.
Abstract: Many well-known interconnection networks, such as kary n-cubes, recursive circulant graphs, generalized recursive circulant graphs, circulant graphs and so on, are shown to belong to the family of cycle composition networks. Recently, various studies about mutually independent hamiltonian cycles, abbreviated as MIHC-s, on interconnection networks are published. In this paper, using an improved construction method, we obtain MIHC-s on cycle composition networks with a much weaker condition than the known result. In fact, we established the existence of MIHC-s in the cycle composition networks and the result is optimal in the sense that the number of MIHC-s we constructed is maximal.
Abstract: The state-of-the-art Bag of Words model in Content-
Based Image Retrieval has been used for years but the relevance
feedback strategies for this model are not fully investigated. Inspired
from text retrieval, the Bag of Words model has the ability to use the
wealth of knowledge and practices available in text retrieval. We
study and experiment the relevance feedback model in text retrieval
for adapting it to image retrieval. The experiments show that the
techniques from text retrieval give good results for image retrieval
and that further improvements is possible.
Abstract: The use of bioindicators plants (lichens, bryophytes
and Sphagnum....) in monitoring pollution by heavy metals has been
the subject of several works. However, few studies have addressed
the impact of specific type-s pollutants (fertilizers, pesticides.) on
these organisms.
We propose in this work to make the highlighting effect of NPKs
(NPK: nitrogen-phosphate-potassium-sulfate (NP2O5K2O) (15,15,15),
at concentrations of 10, 20, 30 , 40 and 50mM/L) on the activity of
detoxification enzymes (GSH/GST, CAT, APX and MDA) of plant
bioindicators (mosses and lichens) after treatment for 3 and 7 days.
This study shows the important role of the defense system in the
accumulation and tolerance to chemical pollutants through the
activation of enzymatic (GST (glutathione-S-transferase, APX
(ascorbat peroxidase), CAT (catalase)) and nonenzymatic biomarkers
(GSH (glutathione), MDA (malondialdehyde)) against oxidative
stress generated by the NPKs.
Abstract: Larval survey was carried out in 6 localities in the
urban areas (Putrajaya) and suburban areas (Kuala Selangor) from
January until December 2010. A total of 520 representative
households in 6 localities were selected. Breeding habitats were
sampled outdoors in the surroundings of housing areas. The study
indicated that the most predominant species found in both areas was
Aedes albopictus with the gardening utensil as a preferred breeding
microhabitat for Putrajaya, in contrast to the artificial containers for
Kuala Selangor. From a total of 1083 mosquito larvae species, 984
were Aedes albopictus larvae, 67 positive larvae of Aedes aegypti
and 32 of Culex larvae. Aedes Index and Container Index were
elevated in Putrajaya with 13% and 11% respectively which is higher
than the standard given by the Ministry of Health, Malaysia. This
results implicating dengue-sensitive skewed to the urban areas.
Breteau Index result also above the standard in both study locations.
Abstract: Seismic design may require non-conventional
concept, due to the fact that the stiffness and layout of the structure
have a great effect on the overall structural behaviour, on the seismic
load intensity as well as on the internal force distribution. To find an
economical and optimal structural configuration the key issue is the
optimal design of the lateral load resisting system. This paper focuses
on the optimal design of regular, concentric braced frame (CBF)
multi-storey steel building structures. The optimal configurations are
determined by a numerical method using genetic algorithm approach,
developed by the authors. Aim is to find structural configurations
with minimum structural cost. The design constraints of objective
function are assigned in accordance with Eurocode 3 and Eurocode 8
guidelines. In this paper the results are presented for various building
geometries, different seismic intensities, and levels of energy
dissipation.
Abstract: The primary cause of Total Hip Replacement (THR)
failure for younger patients is aseptic loosening. This complication is
twice more likely to happen in acetabular cup than in femoral stem.
Excessive micromotion between bone and implant will cause
loosening and it depends in patient activities, age and bone. In this
project, the effects of different metal back design of press fit on
osseointegration of the acetabular cup are carried out. Commercial
acetabular cup designs, namely Spiked, Superfix and Quadrafix are
modelled and analyzed using commercial finite element software.
The diameter of acetabular cup is based on the diameter of acetabular
rim to make sure the component fit to the acetabular cavity. A new
design of acetabular cup are proposed and analyzed to get better
osseointegration between the bones and implant interface. Results
shows that the proposed acetabular cup designs are more stable
compared to other designs with respect to stress and displacement
aspects.
Abstract: The present research was designed to investigate the
anti-microbial activity of aristolochic acid from the root of
Aristolochia bracteata. From the methanolic & ethyl extract extracts
of Aristolochia bracteata aristolochic acid I was isolated and
conformed through IR, NMR & MS. The percentage purity of
aristolochic acid I was determined by UV & HPLC method. Antibacterial
activity of extracts of Aristolochia bracteata and the
isolated compound was determined by disc diffusion method. The
results reveled that the isolated aristolochic acid from methanolic
extract was more pure than the compound from ethyl acetate extract.
The various extracts (500μg/disc) of Aristolochia bracteata showed
moderate antibacterial activity with the average zone of inhibition of
7-18 mm by disc diffusion method. Among the extracts, ethyl acetate
& methanol extracts were shown good anti-microbial activity and the
growth of E.coli (18 mm) was strongly inhibited. Microbial assay of
isolated compound (Aristolochic acid I) from ethyl acetate &
methanol extracts were shown good antimicrobial activity and the
zone of inhibition of both at higher concentration 50 μg/ml was
similar with the standard aristolochic acid. It may be concluded that
the isolated compound of aristolochic acid I has good anti-bacterial
activity.
Abstract: Lipases are enzymes particularly amenable for
immobilization by entrapment methods, as they can work equally
well in aqueous or non-conventional media and long-time stability of
enzyme activity and enantioselectivity is needed to elaborate more
efficient bioprocesses. The improvement of Pseudomonas
fluorescens (Amano AK) lipase characteristics was investigated by
optimizing the immobilization procedure in hybrid organic-inorganic
matrices using ionic liquids as additives. Ionic liquids containing a
more hydrophobic alkyl group in the cationic moiety are beneficial
for the activity of immobilized lipase. Silanes with alkyl- or aryl
nonhydrolizable groups used as precursors in combination with
tetramethoxysilane could generate composites with higher
enantioselectivity compared to the native enzyme in acylation
reactions of secondary alcohols. The optimal effect on both activity
and enantioselectivity was achieved for the composite made from
octyltrimethoxysilane and tetramethoxysilane at 1:1 molar ratio (60%
increase of total activity following immobilization and enantiomeric
ratio of 30). Ionic liquids also demonstrated valuable properties as
reaction media for the studied reactions, comparable with the usual
organic solvent, hexane.
Abstract: The purpose of this study was to explore the complex
flow structure a novel active-type micromixer that based on concept of
Wankle-type rotor. The characteristics of this micromixer are two
folds; a rapid mixing of reagents in a limited space due to the
generation of multiple vortices and a graduate increment in dynamic
pressure as the mixed reagents is delivered to the output ports.
Present micro-mixer is consisted of a rotor with shape of triangle
column, a blending chamber and several inlet and outlet ports. The
geometry of blending chamber is designed to make the rotor can be
freely internal rotated with a constant eccentricity ratio. When the
shape of the blending chamber and the rotor are fixed, the effects of
rotating speed of rotor and the relative locations of ports on the mixing
efficiency are numerical studied. The governing equations are
unsteady, two-dimensional incompressible Navier-Stokes equation
and the working fluid is the water. The species concentration equation
is also solved to reveal the mass transfer process of reagents in various
regions then to evaluate the mixing efficiency.
The dynamic mesh technique was implemented to model the
dynamic volume shrinkage and expansion of three individual
sub-regions of blending chamber when the rotor conducted a complete
rotating cycle. Six types of ports configuration on the mixing
efficiency are considered in a range of Reynolds number from 10 to
300. The rapid mixing process was accomplished with the multiple
vortex structures within a tiny space due to the equilibrium of shear
force, viscous force and inertial force. Results showed that the highest
mixing efficiency could be attained in the following conditions: two
inlet and two outlet ports configuration, that is an included angle of 60
degrees between two inlets and an included angle of 120 degrees
between inlet and outlet ports when Re=10.
Abstract: The selection of parents and breeding strategies for
the successful maize hybrid production will be facilitated by
heterotic groupings of parental lines and determination of combining
abilities of them. Fourteen maize inbred lines, used in maize breeding
programs in Iran, were crossed in a diallel mating design. The 91 F1
hybrids and the 14 parental lines were studied during two years at
four locations of Iran for investigation of combining ability of
gentypes for grain yield and to determine heterotic patterns among
germplasm sources, using both, the Griffing-s method and the biplot
approach for diallel analysis. The graphical representation offered by
biplot analysis allowed a rapid and effective overview of general
combining ability (GCA) and specific combining ability (SCA)
effects of the inbred lines, their performance in crosses, as well as
grouping patterns of similar genotypes. GCA and SCA effects were
significant for grain yield (GY). Based on significant positive GCA
effects, the lines derived from LSC could be used as parent in crosses
to increase GY. The maximum best- parent heterosis values and
highest SCA effects resulted from crosses B73 × MO17 and A679 ×
MO17 for GY. The best heterotic patterns were LSC × RYD, which
would be potentially useful in maize breeding programs to obtain
high-yielding hybrids in the same climate of Iran.
Abstract: The aim of current study was to investigate the
changes in the quality parameters of Holstein bull semen during the
heat stress and the effect of feeding a source of omega-3 fatty acids
in this period. Samples were obtained from 19 Holstein bulls during
the expected time of heat stress in Iran (June to September 2009).
Control group (n=10) were fed a standard concentrate feed while
treatment group (n=9) had this feed top dressed with 100 g of an
omega-3 enriched nutriceutical. Semen quality was assessed on
ejaculates collected after 1, 5, 9 and 12 weeks of supplementation.
Computer-assisted assessment of sperm motility, viability (eosinnigrosin)
and hypo-osmotic swelling test (HOST) were conducted.
Heat stress affected sperm quality parameters by week 5 and 9
(p
Abstract: This paper proposes the concept of aerocapture with
aerodynamic-environment-adaptive variable geometry flexible
aeroshell that vehicle deploys. The flexible membrane is composed
of thin-layer film or textile as its aeroshell in order to solve some
problems obstructing realization of aerocapture technique.
Multi-objective optimization study is conducted to investigate
solutions and derive design guidelines. As a result, solutions which
can avoid aerodynamic heating and enlarge the corridor width up
to 10% are obtained successfully, so that the effectiveness of this
concept can be demonstrated. The deformation-use optimum
solution changes its drag coefficient from 1.6 to 1.1, along with the
change in dynamic pressure. Moreover, optimization results show
that deformation-use solution requires the membrane for which
upper temperature limit and strain limit are more than 700 K and
120%, respectively, and elasticity (Young-s modulus) is of order of
106 Pa.
Abstract: Bangladesh is a developing country with large
population. Demand of electrical energy is increasing day by day
because of increasing population and industrialization. But due to
limited resources, people here are suffering from power crisis
problem which is considered as a major obstacle to the economic
development. In most of the cases, it is extremely difficult to extend
high tension transmission lines to some of the places that are
separated from the mainland. Renewable energy is considered to be
the right choice for providing clean energy to these remote
settlements. This paper proposes a cost effective design of off-grid
wind-diesel hybrid power system using combined heat and power
(CHP) technology in a grid isolated island, Sandwip, Bangladesh.
Design and simulation of the wind-diesel hybrid power system is
performed considering different factors for the island Sandwip.
Detailed economic analysis and comparison with solar PV system
clearly reveals that wind-diesel hybrid power system can be a cost
effective solution for the isolated island like Sandwip.
Abstract: Image Searching was always a problem specially when these images are not properly managed or these are distributed over different locations. Currently different techniques are used for image search. On one end, more features of the image are captured and stored to get better results. Storing and management of such features is itself a time consuming job. While on the other extreme if fewer features are stored the accuracy rate is not satisfactory. Same image stored with different visual properties can further reduce the rate of accuracy. In this paper we present a new concept of using polynomials of sorted histogram of the image. This approach need less overhead and can cope with the difference in visual features of image.
Abstract: A manufacturing inventory model with shortages with
carrying cost, shortage cost, setup cost and demand quantity as
imprecise numbers, instead of real numbers, namely interval number
is considered here. First, a brief survey of the existing works on
comparing and ranking any two interval numbers on the real line
is presented. A common algorithm for the optimum production
quantity (Economic lot-size) per cycle of a single product (so as
to minimize the total average cost) is developed which works well
on interval number optimization under consideration. Finally, the
designed algorithm is illustrated with numerical example.