2,581 research outputs found

    An Efficient Parallel Quarter-sweep Point Iterative Algorithm for Solving Poisson Equation on SMP Parallel Computer

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    A new point iterative algorithm which uses the quarter-sweep approach was shown to be much faster than the full-and half- sweep point iterative algorithms for solving two dimensional Poison equation (Othman el at. 1998». However, the last two algorithms were found to be suitable for parallel implementation (Evans 1984) and Ali el at. (1997». In this paper, the parallel implementation of the new algorithm with the chessboard (CB) strategy on Symmetry Multi Processors (SMP) parallel computer was presented. The experimental results of a test problem were compared with the later two parallel algorithms

    Optimization of copper for the improvement of in vitro plant tissue growth of Solanum nigrum

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    Here was investigated the incorporation of copper in MS medium on growth, and metabolic activities of Solanum nigrum callus. Copper up to 75 µM increased the growth, and thereafter a decline was observed. No considerable alteration in MDA, H2O2, bound phenolics, flavonoids, ascorbate, and copper content was observed with the existence of 25 µM copper, then levels of these parameters were raised with rising copper concentrations. Similarly, 25 µM copper didn't induce a considerable change in lipoxygenase, superoxide dismutase, catalase, peroxidase, phenylalanine ammonia lyase, and polyphenol oxidase activities, however, high levels stimulated these enzymes. Copper at 25 µM didn’t considerably reduce amino acids and soluble proteins, whereas higher concentrations reduced these parameters. Copper treatments reduced the soluble carbohydrates accumulation; only 75 µM enhanced this accumulation. Copper at 25 µM significantly increased the potassium accumulation, whereas higher concentrations reduced this accumulation. From these results, it might be contemplated the optimum effect concerning copper. DOI: http://dx.doi.org/10.5281/zenodo.284864

    Fuzzy logic control for mobile service systems with limited resources

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    It is common to control systems or plants through changing the values of their inputs in continuous or small discrete steps to achieve gradual change of the performance of the plant under control. However, when changing the inputs can only be achieved in large discrete values, problems arise on achieving stability of the plant under control as such large discrete changes in inputs cause large overshoots and oscillation at the outputs. More difficulties arise when multiple plants are competing simultaneously for limited resources of such large discrete values. This paper describes an approach for controlling such plants. The case study presented is to control a proposed system of mobile service units (MSUs) to be used in a mega-event, the Hajj, where different locations/zones will be competing simultaneously for a limited number of MSUs in order to provide adequate services for their continuously changing number of visitors. These MSUs are of high discrete values such that their provision or removal generates a significant change in the performance of the system. Fuzzy logic controllers (FLCs), representing each zone, are developed for issuing requests for MSUs based on their local situations. These requests are evaluated by the control centre using other sets of FLCs to consider global situations. An algorithm is used to respond to these evaluated requests according to their relative importance and issues orders to MSUs to move to the right zone at the right time to provide the appropriate amount of service for the existing number of visitors or what can be called 'just-in-time MSUs' (JIT-MSUs). Simulation results show that such a system can be controlled using the approach suggested by this paper and the response of the system varies with the values of its discrete inputs. Some conclusions and recommendations are drawn for the appropriate discrete input values and their control settings. The procedure for evaluating the different simulation runs for the different control settings is also presented

    Genetic variation among Northern and Southern Egyptian buffaloes using polymerase chain reaction-random amplified polymorphic DNA (PCR-RAPD)

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    The domestic water buffalo is a species of great economic potential, especially in developing countries like Egypt. Egyptian buffalo have been classified according to minor phenotypic differences and their geographical locations. Few studies have taken place to investigate the genetic variations in Egyptian buffalo using  microsatellites analysis. In the present study, 11 random primers were analyzed for the genetic diversity  determination between Northern and Southern Egyptian buffaloes using polymerase chain reaction-random  amplified polymorphic DNA (PCR-RAPD) analysis. 169 bands were amplified for the analyzed 11 random  primers, from which 160 bands (94.67%) for North populations and 168 bands for South population (99.41%).  Out of the 160 amplified bands in North populations, 152 bands were polymorphic with a percentage of 89.94% and only one specific band (0.59%). In South population, all 168 amplified bands were polymorphic, nine bands (5.33%) were specific for this population. The identity index and the genetic distance between North and South populations were measured. The results showed that the two tested populations have the same origin and  belong to one breed without significant genetic difference between their animals.Key words: Buffalo, genetic diversity, polymerase chain reaction (PCR), random amplified polymorphic DNA (RAPD)

    Design Minkowski Shaped Patch Antenna with Rectangular Parasitic Patch Elements for 5.8 GHz Applications

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    Abstract—This paper presents the parametric study on the Minkowski shaped antenna with the rectangular parasitic patch elements. This patch antenna consists four parts – patch, feed line, ground plane and parasitic elements. The rectangular parasitic patch elements are located at the bottom of the Minkowski shaped patch. The parametric study of different patch sizes (Design 2A, Design 2B, Design 2C, Design 2D and Design 2E) is presented in this paper. The antenna parameters studied in this paper are resonant frequencies, return loss at the resonant frequency, bandwidth and realized gain. The target frequency of this antenna is 5.80 GHz for Worldwide Interoperability for Microwave Access (WiMAX) application. It shows the return loss of – 24.477 dB, bandwidth of 254 MHz (5.676 GHz to 5.930 GHz) and a gain of 2.351 dB. Index Terms—Minkowski; patch antenna; gain; return loss; bandwidt

    Performance Evaluation of Multiple Differential Detection for Third Generation Mobile Communication System

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    Third generation mobile communication system is widely used nowadays. One of its parameter standard, which is QPSK modulation has been adopted by International Telecommunication Union (ITU) to be used in IMT-2000. However, due to amplitude variations introduced in QPSK, a rather robust and reliable data modulation technique, namely the p/4-shift Differential QPSK is proposed. For detection purposes, two types of detectors are evaluated for their performance in AWGN and Rayleigh fading channels.A differential detection technique called multiple differential detection technique which uses maximumlikelihood sequence estimation (MLSE) of the transmitted phases is compared with conventional differential detection which uses symbol-by-symbol detection. By using some of the IMT-2000 standard parameters, the simulation results show that multiple differential detection scheme performs much better than conventional differential detection scheme

    Toxicity of Metals to a Freshwater Snail, Melanoides tuberculata

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    Adult freshwater snails Melanoides tuberculata (Gastropod, Thiaridae) were exposed for a four-day period in laboratory conditions to a range of copper (Cu), cadmium (Cd), zinc (Zn), lead (Pb), nickel (Ni), iron (Fe), aluminium (Al), and manganese (Mn) concentrations. Mortality was assessed and median lethal times (LT50) and concentrations (LC50) were calculated. LT50 and LC50 increased with the decrease in mean exposure concentrations and times, respectively, for all metals. The LC50 values for the 96-hour exposures to Cu, Cd, Zn, Pb, Ni, Fe, Al, and Mn were 0.14, 1.49, 3.90, 6.82, 8.46, 8.49, 68.23, and 45.59 mg L−1, respectively. Cu was the most toxic metal to M. tuberculata, followed by Cd, Zn, Pb, Ni, Fe, Mn, and Al (Cu > Cd > Zn > Pb > Ni > Fe > Mn > Al). Metals bioconcentration in M. tuberculata increases with exposure to increasing concentrations and Cu has the highest accumulation (concentration factor) in the soft tissues. A comparison of LC50 values for metals for this species with those for other freshwater gastropods reveals that M. tuberculata is equally sensitive to metals

    Plojdy Analysis and Dna Content of Mutant Banana "Pisang Berangan" Using Flow Cytometry

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    Mutagens cause random changes in the nuclear DNA or cytoplasmic organelles, resulting in gene, chromosomal or genomic mutations and hence, create variability. In this study, flow cytometry (FCM) was used to determine ploidy levels and DNA content in gamma-irradiated variants of mutated Pisang Berangan (cv. Intan, AAA) - a local banana genotype. Induced variants such as short plant stature (stunted growth), late flowering plants (late maturity) and abnormalities in bunch characters were selected to study possible changes at the DNA level. The study showed that DNA content of mutated plants differed from non-irradiated control and that irradiation had the most effect at high doses (40 and 60 Gy). The increase of DNA content in 20 Gy and 30 Gy treated plants was not more than that of the control plants. The values of genomic DNA content of gamma-irradiation variants decreased as the dose of irradiation increased from 20 to 60 Gy, indicating that the high dose of gamma-irradiation had a significant effect on the genome of the plants. The analysis further showed that phenotypic variation due to mutagenesis was reflected in the DNA content of the plants. The results also showed that ploidy levels were not affected by gamma-irradiation even at high doses
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