Abstract: The choice evaluation between oil-immersed and dry-type transformers is often controlled by cost, location, and application. This paper compares the electrical performance of liquid- filled and dry-type transformers, which will assist the customer to choose the right and efficient ones for particular applications. An accurate assessment of the time-average flux density, electric field intensity and voltage distribution in an oil-insulated and a dry-type transformer have been computed and investigated. The detailed transformer modeling and analysis has been carried out to determine electrical parameter distributions. The models of oil-immersed and dry-type transformers are developed and solved by using the finite element method (FEM) to compare the electrical parameters. The effects of non-uniform and non-coherent voltage gradient, flux density and electric field distribution on the power losses and insulation properties of transformers are studied in detail. The results show that, for the same voltage and kilo-volt-ampere (kVA) rating, oil-immersed transformers have better insulation properties and less hysteresis losses than the dry-type.
Abstract: Orthogonal frequency division multiplexing (OFDM) is one of the best candidates for dynamic spectrum access due to its flexibility of spectrum shaping. However, the high sidelobes of the OFDM signal that result in high out-of-band radiation, introduce significant interference to the users operating in its vicinity. This problem becomes more critical in cognitive radio (CR) system that enables the secondary users (SUs) users to access the spectrum holes not used by the primary users (PUs) at that time. In this paper, we present a generalized OFDM framework that has a capability of describing any sidelobe suppression techniques, despite of whether one or a number of techniques are used. Based on that framework, we propose cancellation carrier (CC) technique in conjunction with the generalized sidelobe canceller (GSC) to reduce the out-of-band radiation in the region where the licensed users are operating. Simulation results show that the proposed technique can reduce the out-of-band radiation better when compared with the existing techniques found in the literature.
Abstract: In this paper, effect of marginal quality groundwater
on yield of cotton crop and soil salinity was studied. In this
connection, three irrigation treatments each with four replications
were applied. These treatments were i) use of canal water (T1), ii) use
of marginal quality groundwater from tubewell (T2), and iii)
conjunctive use by mixing with the ratio of 1:1 of canal water and
marginal quality tubewell water (T3).
Water was applied to the crop cultivated in Kharif season 2011; its
quantity has been measured using cut-throat flume. Total 11 watering
each of 50 mm depth have been applied from 20th April to 20th July,
2011. Further, irrigations were stopped due to monsoon rainfall up to
crop harvesting.
Maximum crop yield (seed cotton) was observed under T1 which
was 1,517 kg/ha followed by T3 (mixed canal and tubewell water)
having 1009 kg/ha and T2 i.e. marginal quality groundwater having
709 kg/ha. This concludes that crop yield in T2 and T3 in comparison
to T1was reduced by about 53 and 30% respectively.
It has been observed that yield of cotton crop is below potential
limit for three treatments due to unexpected rainfall at the time of full
flowering season; thus the yield was adversely affected.
However, salt deposition in soil profiles was not observed that is
due to leaching effect of heavy rainfall occurred during monsoon
season.
Abstract: Domestic goats (Capra hircus) are extremely diverse
species and principal animal genetic resource of the developing
world. These facilitate a persistent supply of meat, milk, fibre, and
skin and are considered as important revenue generators in small
pastoral environments. This study aimed to fingerprint β-LG gene at
PCR-RFLP level in native Saudi goat breeds (Ardi, Habsi and Harri)
in an attempt to have a preliminary image of β-LG genotypic patterns
in Saudi breeds as compared to other foreign breeds such as Indian
and Egyptian. Also, the Phylogenetic analysis was done to investigate
evolutionary trends and similarities among the caprine β-LG gene
with that of the other domestic specie, viz. cow, buffalo and sheep.
Blood samples were collected from 300 animals (100 for each breed)
and genomic DNA was extracted. A fragment of the β-LG gene
(427bp) was amplified using specific primers. Subsequent digestion
with Sac II restriction endonuclease revealed two alleles (A and B)
and three different banding patterns or genotypes i.e. AA, AB and
BB. The statistical analysis showed a general trend that β-LG AA
genotype had higher milk yield than β-LG AB and β-LG BB
genotypes. Nucleotide sequencing of the selected β-LG fragments
was done and submitted to GenBank NCBI (Accession No.
KJ544248, KJ588275, KJ588276, KJ783455, KJ783456 and
KJ874959). Phylogenetic analysis on the basis of nucleotide
sequences of native Saudi goats indicated evolutional similarity with
the GenBank reference sequences of goat, Bubalus bubalis and Bos
taurus. However, the origin of sheep which is the most closely
related from the evolutionary point of view, was located some
distance away.
Abstract: Flood wave propagation in river channel flow can be enunciated by nonlinear equations of motion for unsteady flow. It is difficult to find analytical solution of these non-linear equations. Hence, in this paper verification of the finite element model has been carried out against available numerical predictions and field data. The results of the model indicate a good matching with both Preissmann scheme and HEC-RAS model for a river reach of 29km at both sites (15km from upstream and at downstream end) for discharge hydrographs. It also has an agreeable comparison with the Preissemann scheme for the flow depth (stage) hydrographs. The proposed model has also been applying to forecast daily discharges at 400km downstream in the Indus River from Sukkur barrage of Sindh, Pakistan, which demonstrates accurate model predictions with observed the daily discharges. Hence, this model may be utilized for flood warnings in advance.
Abstract: The present study represents the occupational radiation doses received by selected workers of Nuclear Institute of Medicine and Radiotherapy (NIMRA) Jamshoro Pakistan and conducted to discuss about how we be careful and try to avoid make ourselves overconscious. Film badges with unique identification number were issued to radiation worker to detect occupational radiation doses. In this study, only 08 workers with high radiation doses were assessed amongst 35 radiation workers during the period of January 2012 to December 2012. The selected radiation workers’ occupational doses were according to designated work areas and in the range of 1.21 to 7.78 mSv (mili Sieveret) out of the annual dose limit of 20 mSv. By the comparison of different studies and earth’s HNBR (High Natural Background Radiation) locations’ doses, it is concluded that the worker’s high doses are of magnitude of HNBR Regions and were in the acceptable range of National and International regulatory bodies so we must not to show any type of overconsciousness but be careful in handling the radioactive sources.
Abstract: This paper presents the design and layout of a two stage, high speed operational amplifiers using standard 0.35um CMOS technology. The design procedure involves designing the bias circuit, the differential input pair, and the gain stage using CAD tools. Both schematic and layout of the operational amplifier along with the comparison in the results of the two has been presented. The operational amplifier designed, has a gain of 93.51db at low frequencies. It has a gain bandwidth product of 55.07MHz, phase margin of 51.9º and a slew rate of 22v/us for a load of capacitor of 10pF.
Abstract: DC-DC converters are widely used in regulated switched mode power supplies and in DC motor drive applications. There are several sources of unwanted nonlinearity in practical power converters. In addition, their operation is characterized by switching that gives birth to a variety of nonlinear dynamics. DC-DC buck and boost converters controlled by pulse-width modulation (PWM) have been simulated. The voltage waveforms and attractors obtained from the circuit simulation have been studied. With the onset of instability, the phenomenon of subharmonic oscillations, quasi-periodicity, bifurcations, and chaos have been observed. This paper is mainly motivated by potential contributions of chaos theory in the design, analysis and control of power converters, in particular and power electronics circuits, in general.
Abstract: Fossil fuels are the major source to meet the world
energy requirements but its rapidly diminishing rate and adverse
effects on our ecological system are of major concern. Renewable
energy utilization is the need of time to meet the future challenges.
Ocean energy is the one of these promising energy resources. Threefourths
of the earth-s surface is covered by the oceans. This enormous
energy resource is contained in the oceans- waters, the air above the
oceans, and the land beneath them. The renewable energy source of
ocean mainly is contained in waves, ocean current and offshore solar
energy. Very fewer efforts have been made to harness this reliable
and predictable resource. Harnessing of ocean energy needs detail
knowledge of underlying mathematical governing equation and their
analysis. With the advent of extra ordinary computational resources
it is now possible to predict the wave climatology in lab simulation.
Several techniques have been developed mostly stem from numerical
analysis of Navier Stokes equations. This paper presents a brief over
view of such mathematical model and tools to understand and
analyze the wave climatology. Models of 1st, 2nd and 3rd generations
have been developed to estimate the wave characteristics to assess the
power potential. A brief overview of available wave energy
technologies is also given. A novel concept of on-shore wave energy
extraction method is also presented at the end. The concept is based
upon total energy conservation, where energy of wave is transferred
to the flexible converter to increase its kinetic energy. Squeezing
action by the external pressure on the converter body results in
increase velocities at discharge section. High velocity head then can
be used for energy storage or for direct utility of power generation.
This converter utilizes the both potential and kinetic energy of the
waves and designed for on-shore or near-shore application. Increased
wave height at the shore due to shoaling effects increases the
potential energy of the waves which is converted to renewable
energy. This approach will result in economic wave energy
converter due to near shore installation and more dense waves due to
shoaling. Method will be more efficient because of tapping both
potential and kinetic energy of the waves.
Abstract: Human amniotic membrane (HAM) is a useful
biological material for the reconstruction of damaged ocular surface.
The processing and preservation of HAM is critical to prevent the
patients undergoing amniotic membrane transplant (AMT) from cross
infections. For HAM preparation human placenta is obtained after an
elective cesarean delivery. Before collection, the donor is screened
for seronegativity of HCV, Hbs Ag, HIV and Syphilis. After
collection, placenta is washed in balanced salt solution (BSS) in
sterile environment. Amniotic membrane is then separated from the
placenta as well as chorion while keeping the preparation in BSS.
Scrapping of HAM is then carried out manually until all the debris is
removed and clear transparent membrane is acquired. Nitrocellulose
membrane filters are then placed on the stromal side of HAM, cut
around the edges with little membrane folded towards other side
making it easy to separate during surgery. HAM is finally stored in
solution of glycerine and Dulbecco-s Modified Eagle Medium
(DMEM) in 1:1 ratio containing antibiotics. The capped borosil vials
containing HAM are kept at -80°C until use. This vial is thawed to
room temperature and opened under sterile operation theatre
conditions at the time of surgery.
Abstract: Activated carbon was prepared from agricultural waste “almond (Prunus amygdalus) nut shells" by chemical activation with phosphoric acid as an activating agent at 450 °C for 24 hr soaking time. The physical and chemical properties were analyzed. The adsorption of chromium VI from aqueous solution on almond nut shell activated carbon (ASAC) was investigated. The adsorption process parameters pH, agitation speed, agitation time, adsorbent dose were optimized. 98% of Cr VI was sorbed at pH 2 and stirring speed 200 rpm.. Surface structure showed that ASAC has a spongy type structure showing large number of pores
Abstract: An evolutionary computing technique for solving initial value problems in Ordinary Differential Equations is proposed in this paper. Neural network is used as a universal approximator while the adaptive parameters of neural networks are optimized by genetic algorithm. The solution is achieved on the continuous grid of time instead of discrete as in other numerical techniques. The comparison is carried out with classical numerical techniques and the solution is found with a uniform accuracy of MSE ≈ 10-9 .
Abstract: In the forming of ceramic materials the plasticity
concept is commonly used. This term is related to a particular
mechanical behavior when clay is mixed with water. A plastic
ceramic material shows a permanent strain without rupture
when a compressive load produces a shear stress that exceeds
the material-s yield strength. For a plastic ceramic body it
observes a measurable elastic behavior before the yield
strength and when the applied load is removed. In this work, a
mathematical model was developed from applied concepts of
the plasticity theory by using the stress/strain diagram under
compression.
Abstract: The wisest economic decision of United States in the
20th century was establishing the favorable international monetary
system, and capturing the leadership position in it. This decision gave
economic hegemony to the US for the next more than 7 decades. The
continuation of this hegemony till the next decade seems difficult as
the US economy is under continuous streams of recessions since
2007. On the other hand, Chinese economy is progressing with a
very fast speed and is estimated to pass the US economy till 2025, in
various aspects. Will the US be able to continue its leadership in the
IMS? Will China replace US in the international monetary system?
The answers to these questions have been explored by comparing the
economic competitiveness of US and China, with respect to each
other. The paper concludes that the change in global economic
environment will compel US to share the leadership of international
monetary system with China. This sharing will solve most problems
of the current IMS, but will also birth some new problems.
Abstract: The objective of this research is to examine the shear thinning behaviour of mixing flow of non-Newtonian fluid like toothpaste in the dissolution container with rotating stirrer. The problem under investigation is related to the chemical industry. Mixing of fluid is performed in a cylindrical container with rotating stirrer, where stirrer is eccentrically placed on the lid of the container. For the simulation purpose the associated motion of the fluid is considered as revolving of the container, with stick stirrer. For numerical prediction, a time-stepping finite element algorithm in a cylindrical polar coordinate system is adopted based on semi-implicit Taylor-Galerkin/pressure-correction scheme. Numerical solutions are obtained for non-Newtonian fluids employing power law model. Variations with power law index have been analysed, with respect to the flow structure and pressure drop.
Abstract: Many supervised induction algorithms require discrete
data, even while real data often comes in a discrete
and continuous formats. Quality discretization of continuous
attributes is an important problem that has effects on speed,
accuracy and understandability of the induction models. Usually,
discretization and other types of statistical processes are applied
to subsets of the population as the entire population is practically
inaccessible. For this reason we argue that the discretization
performed on a sample of the population is only an estimate of
the entire population. Most of the existing discretization methods,
partition the attribute range into two or several intervals using
a single or a set of cut points. In this paper, we introduce a
technique by using resampling (such as bootstrap) to generate
a set of candidate discretization points and thus, improving the
discretization quality by providing a better estimation towards
the entire population. Thus, the goal of this paper is to observe
whether the resampling technique can lead to better discretization
points, which opens up a new paradigm to construction of
soft decision trees.
Abstract: The world's population continues to grow at a quarter of a million people per day, increasing the consumption of energy. This has made the world to face the problem of energy crisis now days. In response to the energy crisis, the principles of renewable energy gained popularity. There are much advancement made in developing the wind and solar energy farms across the world. These energy farms are not enough to meet the energy requirement of world. This has attracted investors to procure new sources of energy to be substituted. Among these sources, extraction of energy from the waves is considered as best option. The world oceans contain enough energy to meet the requirement of world. Significant advancements in design and technology are being made to make waves as a continuous source of energy. One major hurdle in launching wave energy devices in a developing country like Pakistan is the initial cost. A simple, reliable and cost effective wave energy converter (WEC) is required to meet the nation-s energy need. This paper will present a novel design proposed by team SAS for harnessing wave energy. This paper has three major sections. The first section will give a brief and concise view of ocean wave creation, propagation and the energy carried by them. The second section will explain the designing of SAS-2. A gear chain mechanism is used for transferring the energy from the buoy to a rotary generator. The third section will explain the manufacturing of scaled down model for SAS-2 .Many modifications are made in the trouble shooting stage. The design of SAS-2 is simple and very less maintenance is required. SAS-2 is producing electricity at Clifton. The initial cost of SAS-2 is very low. This has proved SAS- 2 as one of the cost effective and reliable source of harnessing wave energy for developing countries.
Abstract: In this article an evolutionary technique has been used
for the solution of nonlinear Riccati differential equations of fractional order. In this method, genetic algorithm is used as a tool for
the competent global search method hybridized with active-set algorithm for efficient local search. The proposed method has been
successfully applied to solve the different forms of Riccati
differential equations. The strength of proposed method has in its
equal applicability for the integer order case, as well as, fractional
order case. Comparison of the method has been made with standard
numerical techniques as well as the analytic solutions. It is found
that the designed method can provide the solution to the equation
with better accuracy than its counterpart deterministic approaches.
Another advantage of the given approach is to provide results on
entire finite continuous domain unlike other numerical methods
which provide solutions only on discrete grid of points.
Abstract: Vision based tracking problem is solved through a
combination of optical flow, MACH filter and log r-θ mapping.
Optical flow is used for detecting regions of movement in video
frames acquired under variable lighting conditions. The region of
movement is segmented and then searched for the target. A template
is used for target recognition on the segmented regions for detecting
the region of interest. The template is trained offline on a sequence of
target images that are created using the MACH filter and log r-θ
mapping. The template is applied on areas of movement in
successive frames and strong correlation is seen for in-class targets.
Correlation peaks above a certain threshold indicate the presence of
target and the target is tracked over successive frames.
Abstract: Thrombosis can be life threatening, necessitating therefore its instant treatment. Hydergine, a nootropic agent is used as a cognition enhancer in stroke patients but relatively little is known about its anti-thrombolytic effect. To investigate this aspect, in vivo and ex vivo experiments were designed and conducted. Three groups of rats were injected 1.5mg, 3.0mg and 4.5mg hydergine intraperitonealy with and without prior exposure to fresh plasma. Positive and negative controls were run in parallel. Animals were sacrificed after 1.5hrs and BT, CT, PT, INR, APTT, plasma calcium levels were estimated. For ex vivo analyses, each 1ml blood aspirated was exposed to 0.1mg, 0.2mg, 0.3mg dose of hydergine with parallel controls. Parameters analyzed were as above. Statistical analysis was through one-way ANOVA. Dunken-s and Tukey-s tests provided intra-group variance. BT, CT, PT, INR and APTT increased while calcium levels dropped significantly (P