543 research outputs found

    On quantifying fault patterns of the mesh interconnect networks

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    One of the key issues in the design of Multiprocessors System-on-Chip (MP-SoCs), multicomputers, and peerto- peer networks is the development of an efficient communication network to provide high throughput and low latency and its ability to survive beyond the failure of individual components. Generally, the faulty components may be coalesced into fault regions, which are classified into convex and concave shapes. In this paper, we propose a mathematical solution for counting the number of common fault patterns in a 2-D mesh interconnect network including both convex (|-shape, | |-shape, ý-shape) and concave (L-shape, Ushape, T-shape, +-shape, H-shape) regions. The results presented in this paper which have been validated through simulation experiments can play a key role when studying, particularly, the performance analysis of fault-tolerant routing algorithms and measure of a network fault-tolerance expressed as the probability of a disconnection

    Modification of bacterial cell membrane to accelerate decolorization of textile wastewater effluent using microbial fuel cells: role of gamma radiation

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    The aim of the present work was to increase bacterial adhesion on anode via inducing membrane modifications to enhance textile wastewater treatment in Microbial Fuel Cell (MFC). Real textile wastewater was used in mediator-less MFCs for bacterial enrichment. The enriched bacteria were pre-treated by exposure to 1 KGy gamma radiation and were tested in MFC setup. Bacterial cell membrane permeability and cell membrane charges were measured using noninvasive dielectric spectroscopy measurements. The results show that pre-treatment using gamma radiation resulted in biofilm formation and increased cell permeability and exopolysaccharide production; this was reflected in both MFC performance (average voltage 554.67 mV) and decolorization (96.42%) as compared to 392.77 mV and 60.76% decolorization for non-treated cells. At the end of MFC operation, cytotoxicity test was performed for treated wastewater using a dermal cell line, the results obtained show a decrease in toxicity from 24.8 to 0 (v/v%) when cells were exposed to gamma radiation. Fourier-transform infrared (FTIR) spectroscopy showed an increase in exopolysaccharides in bacterial consortium exposed to increasing doses of gamma radiation suggesting that gamma radiation increased exopolysaccharide production, providing transient media for electron transfer and contributing to accelerating MFC performance. Modification of bacterial membrane prior to MFC operation can be considered highly effective as a pre-treatment tool that accelerates MFC performance

    Efficient Total Least Squares State and Parameter Estimation for Differentially Flat Systems

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    This paper proposes an efficient framework for the total least squares (TLS) estimation of differentially flat system states and parameters. Classical ordinary least squares (OLS) estimation assumes: (i) that only the dependent (i.e., output) signals are noisy, and that (ii) the independent (i.e., input) variables are known. In contrast, TLS estimation assumes both the input and output signals to be noisy. Solving TLS problems can be computationally expensive, particularly for nonlinear problems. This challenge arises because the input trajectory must be estimated in a TLS problem, rather than treated as given. This paper addresses this challenge for differentially flat systems by utilizing a pseudospectral expansion to express the input, state, and output trajectories in terms of a flat output trajectory. This transforms the TLS problem into an unconstrained nonlinear programming (NLP) problem with a small number of optimization variables. We demonstrate this framework for an example involving estimating the states and parameters of a second-order nonlinear flat system. Our approach reduces the number of optimization variables from 1503 to 33, while achieving state and parameter estimation errors below 5% and 7%, respectively

    Synthesis and Molluscicidal Activity of Some Newly Substituted Chromene and Pyrano[2,3-c]pyrazole Derivatives

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    The arylidene derivatives 3a-f react with 1,3-cyclohexanedioneand dimedone 4a,b to afford the 4-(2- or 3-pyridyl) or 4-pipronyl-chromene derivatives 6a-l. The arylidene derivatives 3a-c react with the pyrazolone derivatives 7a,b to afford the pyrano[2,3-c]pyrazole derivatives 9af.The molluscicidal activity of the synthesized compounds towards Biomphalaria alexandrina snails, the intermediate host of Schistosoma mansoni, was investigated and most of them showed weak to moderate activity.

    Heterocyclic synthesis with ω-bromoacetophenone: Synthesis of some new pyrazole, pyridazine and furan derivatives

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    p-Bromophenacylnitrile derivatives 3a,b react with hydrazinederivatives under different conditions to afford the diaminopyrazoles 4a,b, the pyridazine-6-imines 5a,b,and 5-aminopyrazoles 11a,b. Refluxing of 5a in ethanol/hydrochloric acid mixture furnished its transformation into the pyridazine-6-one 6 while 5b under the same reaction conditions, underwent ring contraction expelling phenyl hydrazine to afford the furan derivative 7.Compound 7 could also be obtained from 3a upon refluxin ethanol catalyzed by triethylamine. Ethyl  phenacylcyanoacetate 3b reacts with hydrazine hydrate and phenylhydrazine to afford the 4-phenacylpyrazole derivatives11a,b respectively. Compound 3b afforded a mixture ofthe two furan derivatives 12 and 13 upon reflux in ethanolcatalyzed by triethylamine. Compound 3b also undergoesthe coupling reaction with the aromatic diazoniumsalts 14a-d to afford the pyrazole derivatives 16a-d presumablyvia the hydrazo derivatives 15a-d respectively

    Color Portion of Solar Radiation in the Partial Annular Solar Eclipse, October 3rd, 2005, at Helwan, Egypt

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    Measurements were made of various solar radiation components, global, direct and diffuse and their fractions during the partial annular solar eclipse on October 3rd, 2005 at Helwan, Egypt (Lat. 29.866◦ N and Long. 31.20◦ E), and an analysis has been made. The duration of the solar eclipse was 3 h 17 min, and the maximum magnitude of the eclipse in this region was 0.65. The optical depth of the direct component and the relative humidity decreased, while both the transparency and the air temperature increased towards the maximum eclipse. The general trends of the global components are decreasing optical depth and increasing transparency between the first contact and the last contact. The prevailing color during the eclipse duration was diffused infrared (77 % of the total diffuse radiation level)

    Notice of correction

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    No Abstrac

    Effect of genistein and oestradiol on the adrenal cortex of the ovariectomised adult female albino rats

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    Background: Genistein, a naturally occurring soy isoflavone, attracts interest as an effective and safe alternative to hormone replacement therapy for menopausal problems. The aim of the current study was to compare between the effect of genistein and oestradiol on the adrenal cortex of the ovariectomised adult female albino rats. Materials and methods: Twenty rats were used in the current study and divided into four groups, 5 rats in each group; group 1 (control non-ovariectomised), group 2 (ovariectomised), group 3 (ovariectomised + genistein) and group 4 (ovariectomised + oestradiol). The rats were sacrificed after 4 weeks. Both adrenal glands were removed for light microscope using haematoxylin and eosin stain, ultrastructural study and immunohistochemical examination using proliferating cell nuclear antigen, caspase-3, and oestrogen receptor-b. Results: Ovariectomised rats showed signs of degeneration in all zones of adrenal cortex. On the other hand, treatment with genistein showed restoration of the adrenal cortex with less proliferative effect than oestradiol. Conclusions: So, genistein can be used as effective therapy to decrease the symptoms of menopause without fear of cancer development

    Role of vascular endothelial growth factor (VEGF) in diagnosis of pleural effusion of different origins

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    AbstractBackgroundThe undiagnosed pleural effusions are an important clinical problem so scientists spent much effort and time in searching for a new parameter to help in the diagnosis of pleural effusions. Vascular endothelial growth factor (VEGF) helps in differentiation between malignant and inflammatory pleural effusions and might play an important role in tumor progression and the formation of malignant effusions.Aim of the workTo determine the level of pleural fluid VEGF in order to evaluate its value as a marker for differentiation between different types of pleural effusions.Subjects and methodsThe present study was conducted on 73 patients with pleural effusion, admitted to Kasr Elaini Hospital (Chest Department) during the period from August 2011 to October 2012, after having their written consent. All patients were subjected basically to full history taking, thorough clinical examination, routine laboratory investigations, plain chest radiography thoracentesis. Medical thoracoscopy was carried out for cases with undiagnosed exudative pleural effusion (n=46).ResultsPleural fluid VEGF, and pleural fluid VEGF/serum VEGF ratio both are highest in malignant pleural effusion with statistically high significance (p<0.001), followed by infectious effusion then tuberculous one. Using ROC curve analysis, the cut-off used for VEGF in pleural fluid in discriminating malignant from other groups is 1800pg/ml with sensitivity of 95% and specificity of 96%.ConclusionVEGF is highest in malignant pleural effusion. The differential diagnosis of effusions might be further improved by including vascular endothelial growth factor concentrations into the diagnostic armentarium available to the clinician

    Gravity observations at Sinai Peninsula and its geophysical and geodetic applications

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    AbstractSouth Sinai is an interesting region from both tectonic and seismological settings. Tectonically, Sinai Peninsula is strongly dominated by its active boundaries due to its location at the triple junction among the Gulf of Suez rift, the Aqaba–Levant transform fault and the Red Sea Rift. Moreover, reported seismological activities along the three tectonic boundaries indicate its continuous activities.It is thus of great interest to delineate the subsurface geological structure responsible of its tectonic settings and its relation to the seismological activity. Therefore, terrestrial gravity observation has been carried out to figure out the sub-surface structure representing its tectonic settings.On the other hand, the location of Sinai Peninsula between Gulf of Suez, Gulf of Aqepa and Red Sea has made the satellite altimetry data an optimum tool to determine the Gravity sources on the marine regions bounding the Sinai region. Finally, temporal gravity variation of the GRACE satellite mission, launched in 2003 gives the opportunity to monitor its temporal gravity variation on regional scale. Temporal gravity variation from GRACE demonstrates any possible mass redistribution along the pounding tectonic settings and its relation to seismicity.Observed gravity map shows significant gravity anomalies attributed to tectonic and seismicity. Satellite altimetry and gravity data are considered to be a valuable source of data to determine the offshore subsurface structure. Temporal gravity variations from GRACE shows important zones of mass redistribution attributed to its new tectonics and its relation to the seismological activities. Integrating all available data sheds more light on the geodynamic behavior of the selected region and its relation to the seismic activities
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