Search results for: generalized gamma
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 1167

Search results for: generalized gamma

717 On Hankel Matrices Approach to Interpolation Problem in Infinite and Finite Fields

Authors: Ivan Baravy

Abstract:

Interpolation problem, as it was initially posed in terms of polynomials, is well researched. However, further mathematical developments extended it significantly. Trigonometric interpolation is widely used in Fourier analysis, while its generalized representation as exponential interpolation is applicable to such problem of mathematical physics as modelling of Ziegler-Biersack-Littmark repulsive interatomic potentials. Formulated for finite fields, this problem arises in decoding Reed--Solomon codes. This paper shows the relation between different interpretations of the problem through the class of matrices of special structure - Hankel matrices.

Keywords: Berlekamp-Massey algorithm, exponential interpolation, finite fields, Hankel matrices, Hankel polynomials

Procedia PDF Downloads 498
716 Quantile Coherence Analysis: Application to Precipitation Data

Authors: Yaeji Lim, Hee-Seok Oh

Abstract:

The coherence analysis measures the linear time-invariant relationship between two data sets and has been studied various fields such as signal processing, engineering, and medical science. However classical coherence analysis tends to be sensitive to outliers and focuses only on mean relationship. In this paper, we generalized cross periodogram to quantile cross periodogram and provide richer inter-relationship between two data sets. This is a general version of Laplace cross periodogram. We prove its asymptotic distribution under the long range process and compare them with ordinary coherence through numerical examples. We also present real data example to confirm the usefulness of quantile coherence analysis.

Keywords: coherence, cross periodogram, spectrum, quantile

Procedia PDF Downloads 369
715 Sorting Maize Haploids from Hybrids Using Single-Kernel Near-Infrared Spectroscopy

Authors: Paul R Armstrong

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Doubled haploids (DHs) have become an important breeding tool for creating maize inbred lines, although several bottlenecks in the DH production process limit wider development, application, and adoption of the technique. DH kernels are typically sorted manually and represent about 10% of the seeds in a much larger pool where the remaining 90% are hybrid siblings. This introduces time constraints on DH production and manual sorting is often not accurate. Automated sorting based on the chemical composition of the kernel can be effective, but devices, namely NMR, have not achieved the sorting speed to be a cost-effective replacement to manual sorting. This study evaluated a single kernel near-infrared reflectance spectroscopy (skNIR) platform to accurately identify DH kernels based on oil content. The skNIR platform is a higher-throughput device, approximately 3 seeds/s, that uses spectra to predict oil content of each kernel from maize crosses intentionally developed to create larger than normal oil differences, 1.5%-2%, between DH and hybrid kernels. Spectra from the skNIR were used to construct a partial least squares regression (PLS) model for oil and for a categorical reference model of 1 (DH kernel) or 2 (hybrid kernel) and then used to sort several crosses to evaluate performance. Two approaches were used for sorting. The first used a general PLS model developed from all crosses to predict oil content and then used for sorting each induction cross, the second was the development of a specific model from a single induction cross where approximately fifty DH and one hundred hybrid kernels used. This second approach used a categorical reference value of 1 and 2, instead of oil content, for the PLS model and kernels selected for the calibration set were manually referenced based on traditional commercial methods using coloration of the tip cap and germ areas. The generalized PLS oil model statistics were R2 = 0.94 and RMSE = .93% for kernels spanning an oil content of 2.7% to 19.3%. Sorting by this model resulted in extracting 55% to 85% of haploid kernels from the four induction crosses. Using the second method of generating a model for each cross yielded model statistics ranging from R2s = 0.96 to 0.98 and RMSEs from 0.08 to 0.10. Sorting in this case resulted in 100% correct classification but required models that were cross. In summary, the first generalized model oil method could be used to sort a significant number of kernels from a kernel pool but was not close to the accuracy of developing a sorting model from a single cross. The penalty for the second method is that a PLS model would need to be developed for each individual cross. In conclusion both methods could find useful application in the sorting of DH from hybrid kernels.

Keywords: NIR, haploids, maize, sorting

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714 Mixtures of Length-Biased Weibull Distributions for Loss Severity Modelling

Authors: Taehan Bae

Abstract:

In this paper, a class of length-biased Weibull mixtures is presented to model loss severity data. The proposed model generalizes the Erlang mixtures with the common scale parameter, and it shares many important modelling features, such as flexibility to fit various data distribution shapes and weak-denseness in the class of positive continuous distributions, with the Erlang mixtures. We show that the asymptotic tail estimate of the length-biased Weibull mixture is Weibull-type, which makes the model effective to fit loss severity data with heavy-tailed observations. A method of statistical estimation is discussed with applications on real catastrophic loss data sets.

Keywords: Erlang mixture, length-biased distribution, transformed gamma distribution, asymptotic tail estimate, EM algorithm, expectation-maximization algorithm

Procedia PDF Downloads 205
713 Linear Stability of Convection in an Inclined Channel with Nanofluid Saturated Porous Medium

Authors: D. Srinivasacharya, Nidhi Humnekar

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The goal of this research is to numerically investigate the convection of nanofluid flow in an inclined porous channel. Brownian motion and thermophoresis effects are accounted for by nanofluid. In addition, the flow in the porous region governs Brinkman’s equation. The perturbed state of the generalized eigenvalue problem is obtained using normal mode analysis, and Chebyshev spectral collocation was used to solve this problem. For various values of the governing parameters, the critical wavenumber and critical Rayleigh number are calculated, and preferred modes are identified.

Keywords: Brinkman model, inclined channel, nanofluid, linear stability, porous media

Procedia PDF Downloads 95
712 Radiological Hazard Assessments and Control of Radionuclides Emitted from Building Materials in Kuwait Using Expert Systems

Authors: Abdulla Almulla, Wafaa Mahdi

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Building materials can make a significant contribution to the level of natural radioactivity in closed dwelling areas. Therefore, developing an expert system for monitoring the activity concentrations (ACs) of naturally occurring radioactive materials (NORMs) existing in building materials is useful for limiting the population’s exposure to gamma radiation emitted from those materials. The present work not only is aimed at examining the indoor radon concentration emitted by the building materials that are originated from various countries but are commercially available in Kuwait, but also is aimed at developing an expert system for monitoring the radiation emitted from these materials and classifying it as normal (acceptable) or dangerous (unacceptable). This system makes it possible to always monitor any radiological risks to human health. When detecting high doses of radiation, the system gives warning messages.

Keywords: building materials, NORMs, HNBRA, radionuclides, activity concentrations, expert systems

Procedia PDF Downloads 139
711 Analysis of a Generalized Sharma-Tasso-Olver Equation with Variable Coefficients

Authors: Fadi Awawdeh, O. Alsayyed, S. Al-Shará

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Considering the inhomogeneities of media, the variable-coefficient Sharma-Tasso-Olver (STO) equation is hereby investigated with the aid of symbolic computation. A newly developed simplified bilinear method is described for the solution of considered equation. Without any constraints on the coefficient functions, multiple kink solutions are obtained. Parametric analysis is carried out in order to analyze the effects of the coefficient functions on the stabilities and propagation characteristics of the solitonic waves.

Keywords: Hirota bilinear method, multiple kink solution, Sharma-Tasso-Olver equation, inhomogeneity of media

Procedia PDF Downloads 495
710 Modelling of the Linear Operator in the Representation of the Function of Wave of a Micro Particle

Authors: Mohammedi Ferhate

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This paper deals with the generalized the notion of the function of wave a micro particle moving free, the concept of the linear operator in the representation function delta of Dirac which is a generalization of the symbol of Kronecker to the case of a continuous variation of the sizes concerned with the condition of orthonormation of the Eigen functions the use of linear operators and their Eigen functions in connection with the solution of given differential equations, it is of interest to study the properties of the operators themselves and determine which of them follow purely from the nature of the operators, without reference to specific forms of Eigen functions. The models simulation examples are also presented.

Keywords: function, operator, simulation, wave

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709 Survival Data with Incomplete Missing Categorical Covariates

Authors: Madaki Umar Yusuf, Mohd Rizam B. Abubakar

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The survival censored data with incomplete covariate data is a common occurrence in many studies in which the outcome is survival time. With model when the missing covariates are categorical, a useful technique for obtaining parameter estimates is the EM by the method of weights. The survival outcome for the class of generalized linear model is applied and this method requires the estimation of the parameters of the distribution of the covariates. In this paper, we propose some clinical trials with ve covariates, four of which have some missing values which clearly show that they were fully censored data.

Keywords: EM algorithm, incomplete categorical covariates, ignorable missing data, missing at random (MAR), Weibull Distribution

Procedia PDF Downloads 384
708 Nullity of t-Tupple Graphs

Authors: Khidir R. Sharaf, Didar A. Ali

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The nullity η (G) of a graph is the occurrence of zero as an eigenvalue in its spectra. A zero-sum weighting of a graph G is real valued function, say f from vertices of G to the set of real numbers, provided that for each vertex of G the summation of the weights f (w) over all neighborhood w of v is zero for each v in G.A high zero-sum weighting of G is one that uses maximum number of non-zero independent variables. If G is graph with an end vertex, and if H is an induced sub-graph of G obtained by deleting this vertex together with the vertex adjacent to it, then, η(G)= η(H). In this paper, a high zero-sum weighting technique and the end vertex procedure are applied to evaluate the nullity of t-tupple and generalized t-tupple graphs are derived and determined for some special types of graphs. Also, we introduce and prove some important results about the t-tupple coalescence, Cartesian and Kronecker products of nut graphs.

Keywords: graph theory, graph spectra, nullity of graphs, statistic

Procedia PDF Downloads 219
707 Problems Encountered in Teaching English as a Second Language in Asia

Authors: Geraldine Agbor Ojong

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This paper conveys some of the problems teachers of ESL face in classroom settings in Thailand. The results of this paper is achieved through close and open ended questionaires administered to a group of English language teachers of three prominent schools in Kaengkhoi, saraburi Province, Thailand.(Saengvithaya school, kaengkhoi school and Pytoon withaya school). Face to face interview of some foreign teachers and students selected randomly And general observation. The data was analysed by frequency distribution and percentage: The result of the study may be generalized so that the conference committee can suggest possible solutions or give contributing ideas on how to handle some of these problems.

Keywords: Asian, colonize, ESL, foreign country

Procedia PDF Downloads 425
706 γ-Irradiation of Oat β- Glucan: Effect on Antioxidant and Antiproliferative Properties

Authors: Asima Shah, F. A. Masoodi, Adil Gani, Bilal Ahmad Ashwar

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The present study was designed to evaluate the effect of γ-rays on the antioxidant and antiproliferative potential of β-glucan isolated from oats. The β-glucan was irradiated with 0, 2, 6, and 10 kGy by gamma ray. The samples were characterized by FT-IR, GPC, and quantitative estimation by Megazyme β-glucan assay kit. The average molecular weight of non-irradiated β-glucan was 199 kDa that decreased to 70 kDa at 10 kGy. Both FT-IR spectrum and chemical analysis revealed that the extracted β-glucan was pure having minor impurities. Antioxidant activity was evaluated by DPPH, lipid peroxidation, reducing power, metal chelating ability and oxidative DNA damage assays. Results revealed that the antioxidant activity of β-glucan increased with the increase in irradiation dose. Irradiated β-glucan also exhibited dose dependent cancer cell growth inhibition with irradiation doses. The study revealed that low molecular weight β-glucan with enhanced antioxidant and antiproliferative activities can be produced by a simple irradiation method.

Keywords: γ-irradiation, antioxidant activity, antiproliferative activity, β-glucan, oats

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705 Artificial Neural Networks Application on Nusselt Number and Pressure Drop Prediction in Triangular Corrugated Plate Heat Exchanger

Authors: Hany Elsaid Fawaz Abdallah

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This study presents a new artificial neural network(ANN) model to predict the Nusselt Number and pressure drop for the turbulent flow in a triangular corrugated plate heat exchanger for forced air and turbulent water flow. An experimental investigation was performed to create a new dataset for the Nusselt Number and pressure drop values in the following range of dimensionless parameters: The plate corrugation angles (from 0° to 60°), the Reynolds number (from 10000 to 40000), pitch to height ratio (from 1 to 4), and Prandtl number (from 0.7 to 200). Based on the ANN performance graph, the three-layer structure with {12-8-6} hidden neurons has been chosen. The training procedure includes back-propagation with the biases and weight adjustment, the evaluation of the loss function for the training and validation dataset and feed-forward propagation of the input parameters. The linear function was used at the output layer as the activation function, while for the hidden layers, the rectified linear unit activation function was utilized. In order to accelerate the ANN training, the loss function minimization may be achieved by the adaptive moment estimation algorithm (ADAM). The ‘‘MinMax’’ normalization approach was utilized to avoid the increase in the training time due to drastic differences in the loss function gradients with respect to the values of weights. Since the test dataset is not being used for the ANN training, a cross-validation technique is applied to the ANN network using the new data. Such procedure was repeated until loss function convergence was achieved or for 4000 epochs with a batch size of 200 points. The program code was written in Python 3.0 using open-source ANN libraries such as Scikit learn, TensorFlow and Keras libraries. The mean average percent error values of 9.4% for the Nusselt number and 8.2% for pressure drop for the ANN model have been achieved. Therefore, higher accuracy compared to the generalized correlations was achieved. The performance validation of the obtained model was based on a comparison of predicted data with the experimental results yielding excellent accuracy.

Keywords: artificial neural networks, corrugated channel, heat transfer enhancement, Nusselt number, pressure drop, generalized correlations

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704 Role of von Willebrand Factor and ADAMTS13 In The Prediction of Thrombotic Complications In Patients With COVID-19

Authors: Nataliya V. Dolgushina, Elena A. Gorodnova, Olga S. Beznoshenco, Andrey Yu Romanov, Irina V. Menzhinskaya, Lyubov V. Krechetova, Gennady T. Suchich

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In patients with COVID-19, generalized hypercoagulability can lead to the development of severe coagulopathy. This event is accompanied by the development of a pronounced inflammatory reaction. The observational prospective study included 39 patients with mild COVID-19 and 102 patients with moderate and severe COVID-19. Patients were then stratified into groups depending on the risk of venous thromboembolism. vWF to ADAMTS-13 concentrations and activity ratios were significantly higher in patients with a high venous thromboembolism risks in patients with moderate and severe forms COVID-19.

Keywords: ADAMTS-13, COVID-19, hypercoagulation, thrombosis, von Willebrand factor

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703 Theoretical Investigation on Electronic and Magnetic Properties of Cubic PrMnO3 Perovskite

Authors: B. Bouadjemi, S. Bentata, W. Benstaali, A. Abbad, T. Lantri, A. Zitouni

Abstract:

The purpose of this study was to investigate the structural,electronic and magnetic properties of the cubic praseodymium oxides perovskites PrMnO3. It includes our calculations based on the use of the density functional theory (DFT) with both generalized gradient approximation (GGA) and GGA+U approaches, The spin polarized electronic band structures and densities of states as well as the integer value of the magnetic moment of the unit cell (6 μB) illustrate that PrMnO3 is half-metallic ferromagnetic. The study prove that the compound is half-metallic ferromagnetic however the results obtained, make the cubic PrMnO3 a promising candidate for application in spintronics.

Keywords: cubic, DFT, electronic properties, magnetic moment, spintronics

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702 Calculated Structural and Electronic Properties of Mg and Bi

Authors: G. Patricia Abdel Rahim, Jairo Arbey Rodriguez M, María Guadalupe Moreno Armenta

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The present study shows the structural, electronic and magnetic properties of magnesium (Mg) and bismuth (Bi) in a supercell (1X1X5). For both materials were studied in five crystalline structures: rock salt (NaCl), cesium chloride (CsCl), zinc-blende (ZB), wurtzite (WZ), and nickel arsenide (NiAs), using the Density Functional Theory (DFT), the Generalized Gradient Approximation (GGA), and the Full Potential Linear Augmented Plane Wave (FP-LAPW) method. By means of fitting the Murnaghan's state equation we determine the lattice constant, the bulk modulus and it's derived with the pressure. Also we calculated the density of states (DOS) and the band structure.

Keywords: bismuth, magnesium, pseudo-potential, supercell

Procedia PDF Downloads 799
701 Foundation Settlement Determination: A Simplified Approach

Authors: Adewoyin O. Olusegun, Emmanuel O. Joshua, Marvel L. Akinyemi

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The heterogeneous nature of the subsurface requires the use of factual information to deal with rather than assumptions or generalized equations. Therefore, there is need to determine the actual rate of settlement possible in the soil before structures are built on it. This information will help in determining the type of foundation design and the kind of reinforcement that will be necessary in constructions. This paper presents a simplified and a faster approach for determining foundation settlement in any type of soil using real field data acquired from seismic refraction techniques and cone penetration tests. This approach was also able to determine the depth of settlement of each strata of soil. The results obtained revealed the different settlement time and depth of settlement possible.

Keywords: heterogeneous, settlement, foundation, seismic, technique

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700 Modelling Sudden Deaths from Myocardial Infarction and Stroke

Authors: Y. S. Yusoff, G. Streftaris, H. R Waters

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Death within 30 days is an important factor to be looked into, as there is a significant risk of deaths immediately following or soon after, Myocardial Infarction (MI) or stroke. In this paper, we will model the deaths within 30 days following a Myocardial Infarction (MI) or stroke in the UK. We will see how the probabilities of sudden deaths from MI or stroke have changed over the period 1981-2000. We will model the sudden deaths using a Generalized Linear Model (GLM), fitted using the R statistical package, under a Binomial distribution for the number of sudden deaths. We parameterize our model using the extensive and detailed data from the Framingham Heart Study, adjusted to match UK rates. The results show that there is a reduction for the sudden deaths following a MI over time but no significant improvement for sudden deaths following a stroke.

Keywords: sudden deaths, myocardial infarction, stroke, ischemic heart disease

Procedia PDF Downloads 276
699 Effect of the Support Shape on Fischer-Tropsch Cobalt Catalyst Performance

Authors: Jian Huang, Weixin Qian, Hongfang Ma, Haitao Zhang, Weiyong Ying

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Cobalt catalysts were supported on extruded silica carrier and different-type (SiO2, γ-Al2O3) commercial supports with different shapes and sizes to produce heavy hydrocarbons for Fischer-Tropsch synthesis. The catalysts were characterized by N2 physisorption and H2-TPR. The catalytic performance of the catalysts was tested in a fixed bed reactor. The results of Fischer-Tropsch synthesis performance showed that the cobalt catalyst supported on spherical silica supports displayed a higher activity and a higher selectivity to C5+ products, due to the fact that the active components were only distributed in the surface layer of spherical carrier, and the influence of gas diffusion restriction on catalytic performance was weakened. Therefore, it can be concluded that the eggshell cobalt catalyst was superior to precious metals modified catalysts in the synthesis of heavy hydrocarbons.

Keywords: fischer-tropsch synthesis, cobalt catalyst, support shape, heavy hydrocarbons

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698 Robust Half-Metallicity and Magnetic Properties of Cubic PrMnO3 Perovskite

Authors: B. Bouadjemi, S. Bentata, W. Benstaali, A. Abbad, T. Lantri, A. Zitouni

Abstract:

The purpose of this study was to investigate the structural,electronic and magnetic properties of the cubic praseodymium oxides perovskites PrMnO3. It includes our calculations based on the use of the density functional theory (DFT) with both generalized gradient approximation (GGA) and GGA+U approaches, The spin polarized electronic band structures and densities of states aswellas the integer value of the magnetic moment of the unit cell (6 μB) illustrate that PrMnO3 is half-metallic ferromagnetic. The study shows that the robust half-metallicity makes the cubic PrMnO3 a promising candidate for application in spintronics.

Keywords: Perovskite, DFT, electronic properties, Magnetic moment, half-metallic

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697 Structural, Electronic and Magnetic Properties of Co and Mn Doped CDTE

Authors: A. Zitouni, S. Bentata, B. Bouadjemi, T. Lantri, W. Benstaali, A. Zoubir, S. Cherid, A. Sefir

Abstract:

The structural, electronic, and magnetic properties of transition metal Co and Mn doped zinc-blende semiconductor CdTe were calculated using the density functional theory (DFT) with both generalized gradient approximation (GGA). We have analyzed the structural parameters, charge and spin densities, total and partial densities of states. We find that the Co and Mn doped zinc blende CdTe show half-metallic behavior with a total magnetic moment of 6.0 and 10.0 µB, respectively.The results obtained, make the Co and Mn doped CdTe a promising candidate for application in spintronics.

Keywords: first-principles, half-metallic, diluted magnetic semiconductor, magnetic moment

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696 Inflammatory and Cardio Hypertrophic Remodeling Biomarkers in Patients with Fabry Disease

Authors: Margarita Ivanova, Julia Dao, Andrew Friedman, Neil Kasaci, Rekha Gopal, Ozlem Goker-Alpan

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In Fabry disease (FD), α-galactosidase A (α-Gal A) deficiency leads to the accumulation of globotriaosylceramide (Lyso-Gb3 and Gb3), triggering a pathologic cascade that causes the severity of organs damage. The heart is one of the several organs with high sensitivity to the α-Gal A deficiency. A subgroup of patients with significant residual of α-Gal A activity with primary cardiac involvement is occasionally referred to as “cardiac variant.” The cardiovascular complications are most frequently encountered, contributing substantially to morbidity, and are the leading cause of premature death in male and female patients with FD. The deposition of Lyso-Gb-3 and Gb-3 within the myocardium affects cardiac function with resultant progressive cardiovascular pathology. Gb-3 and Lyso-Gb-3 accumulation at the cellular level trigger a cascade of events leading to end-stage fibrosis. In the cardiac tissue, Lyso-Gb-3 deposition is associated with the increased release of inflammatory factors and transforming growth factors. Infiltration of lymphocytes and macrophages into endomyocardial tissue indicates that inflammation plays a significant role in cardiac damage. Moreover, accumulated data suggest that chronic inflammation leads to multisystemic FD pathology even under enzyme replacement therapy (ERT). NF-κB activation plays a subsequent role in the inflammatory response to cardiac dysfunction and advanced heart failure in the general population. TNFalpha/NF-κB signaling protects the myocardial evoking by ischemic preconditioning; however, this protective effect depends on the concentration of TNF-α. Thus, we hypothesize that TNF-α is a critical factor in determining the grade of cardio-pathology. Cardiac hypertrophy corresponds to the expansion of the coronary vasculature to maintain a sufficient supply of nutrients and oxygen. Coronary activation of angiogenesis and fibrosis plays a vital role in cardiac vascularization, hypertrophy, and tissue remodeling. We suggest that the interaction between the inflammatory pathways and cardiac vascularization is a bi-directional process controlled by secreted cytokines and growth factors. The co-coordination of these two processes has never been explored in FD. In a cohort of 40 patients with FD, biomarkers associated with inflammation and cardio hypertrophic remodeling were studied. FD patients were categorized into three groups based on LVmass/DSA, LVEF, and ECG abnormalities: FD with no cardio complication, FD with moderate cardio complication, and severe cardio complication. Serum levels of NF-kB, TNFalpha, Il-6, Il-2, MCP1, ING-gamma, VEGF, IGF-1, TGFβ, and FGF2 were quantified by enzyme-linked immunosorbent assays (ELISA). Among the biomarkers, MCP-1, INF-gamma, VEGF, TNF-alpha, and TGF-beta were elevated in FD patients. Some of these biomarkers also have the potential to correlate with cardio pathology in FD. Conclusion: The study provides information about the role of inflammatory pathways and biomarkers of cardio hypertrophic remodeling in FD patients. This study will also reveal the mechanisms that link intracellular accumulation of Lyso-GB-3 and Gb3 to the development of cardiomyopathy with myocardial thickening and resultant fibrosis.

Keywords: biomarkers, Fabry disease, inflammation, growth factors

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695 Some Fundamental Physical Properties of BiGaO₃ Cubic Perovskite

Authors: B. Gueridi, T. Chihi, M. Fatmi, A. Faci

Abstract:

Some fundamental physical properties of BiGaO₃ were investigated under pressure and temperature effect using generalized gradient approximation and local density approximation approaches. The effect of orientation on Debye temperature and sound waves velocities were estimated from elastic constants. The value of the bulk modulus of BiGaO₃ is a sign of its high hardness because it is linked to an isotropic deformation. BiGaO₃ is a semiconductor and ductile material with covalent bonding (Ga–O), and the Bi-O bonding is ionic. The optical transitions were observed when electrons pass from the top of the valence band (O-2p) to the bottom of the conduction band (Ga-4p or Bi-6p). The thermodynamic parameters are determined in temperature and pressure ranging from 0 to 1800 K and 0 to 50 GPa.

Keywords: BiGaO₃ perovskite, optical absorption, first principle, band structure

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694 Experimental Technique to Study Colloid Deposition in Porous Media

Authors: Abdelkader Djehiche, Mostefa Gafsi, Henri Bertin, Aziz Omari

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The flows of colloidal suspensions in porous media find many applications in fields such as Petroleum, Hydraulic engineering, deep-bed filtration. For each application, the scientific problems can be summarized the flow in porous medium of a colloidal suspension whose particles having characteristic dimension is considerable in comparison with the pores dimension. In certain cases, one can observe a deposit of particles on the surface of the pores which results in a significant modification in the physical properties of the porous medium. The objective of our study is to use a non-destructive experimental method, the attenuation of g-rays, to study the influence of the number of Peclet on the deposit of latex particles in a consolidated porous medium. The first results obtained show a good agreement between local and global measurements of the deposit of the particles in porous medium. The deposit takes place in a progressive way along the porous medium and leads to a monolayer deposit of which the average thickness is of about the size diameter of the colloidal particles.

Keywords: colloid, gamma ray, Peclet number, permeability, porous medium

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693 Investigation of Polymer Composite for High Dose Dosimetry

Authors: Esther Lorrayne M. Pereira, Adriana S. M. Batista, Fabíola A. S. Ribeiro, Adelina P. Santos, Luiz O. Faria

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In this work we have prepared nanocomposites made by mixing Poli (vinilidene fluoride) (PVDF), zirconium oxide (ZrO₂) and multi–walled carbon nanotubes (MWCNTs) aiming to find dosimetric properties for applications in high dose dosimetry. The samples were irradiated with a Co-60 source at constant dose rate (16.7 kGy/h), with doses ranging from 100 to 2750 kGy. The UV-Vis and FTIR spectrophotometry have been used to monitor the appearing of C=C conjugated bonds and radio-oxidation of carbon (C=O). FTIR spectrometry has that the absorbance intensities at 1715 cm⁻¹ and 1730 cm⁻¹ can be used for high dosimetry purposes for gamma doses ranging from 500 to 2750 kGy. In this range, it is possible to observe a linear relationship between Abs & Dose. Fading of signal was evaluated for one month and reproducibility in 2000 kGy dose. Scanning Electron Microscopy (SEM) and Energy-dispersive X-ray spectroscopy (EDX) was used for evaluated the dispersion ZrO₂ and MWCNT in the matrix of the PVDF.

Keywords: polymer, composite, high dose dosimetry, PVDF/ZrO₂/MWCNT

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692 Application of Generalized Taguchi and Design of Experiment Methodology for Rebar Production at an Integrated Steel Plant

Authors: S. B. V. S. P. Sastry, V. V. S. Kesava Rao

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In this paper, x-ray impact of Taguchi method and design of experiment philosophy to project relationship between various factors leading to output yield strength of rebar is studied. In bar mill of an integrated steel plant, there are two production lines called as line 1 and line 2. The metallic properties e.g. yield strength of finished product of the same material is varying for a particular grade material when rolled simultaneously in both the lines. A study has been carried out to set the process parameters at optimal level for obtaining equal value of yield strength simultaneously for both lines.

Keywords: bar mill, design of experiment, taguchi, yield strength

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691 Automated Buffer Box Assembly Cell Concept for the Canadian Used Fuel Packing Plant

Authors: Dimitrie Marinceu, Alan Murchison

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The Canadian Used Fuel Container (UFC) is a mid-size hemispherical headed copper coated steel container measuring 2.5 meters in length and 0.5 meters in diameter containing 48 used fuel bundles. The contained used fuel produces significant gamma radiation requiring automated assembly processes to complete the assembly. The design throughput of 2,500 UFCs per year places constraints on equipment and hot cell design for repeatability, speed of processing, robustness and recovery from upset conditions. After UFC assembly, the UFC is inserted into a Buffer Box (BB). The BB is made from adequately pre-shaped blocks (lower and upper block) and Highly Compacted Bentonite (HCB) material. The blocks are practically ‘sandwiching’ the UFC between them after assembly. This paper identifies one possible approach for the BB automatic assembly cell and processes. Automation of the BB assembly will have a significant positive impact on nuclear safety, quality, productivity, and reliability.

Keywords: used fuel packing plant, automatic assembly cell, used fuel container, buffer box, deep geological repository

Procedia PDF Downloads 256
690 Simscape Library for Large-Signal Physical Network Modeling of Inertial Microelectromechanical Devices

Authors: S. Srinivasan, E. Cretu

Abstract:

The information flow (e.g. block-diagram or signal flow graph) paradigm for the design and simulation of Microelectromechanical (MEMS)-based systems allows to model MEMS devices using causal transfer functions easily, and interface them with electronic subsystems for fast system-level explorations of design alternatives and optimization. Nevertheless, the physical bi-directional coupling between different energy domains is not easily captured in causal signal flow modeling. Moreover, models of fundamental components acting as building blocks (e.g. gap-varying MEMS capacitor structures) depend not only on the component, but also on the specific excitation mode (e.g. voltage or charge-actuation). In contrast, the energy flow modeling paradigm in terms of generalized across-through variables offers an acausal perspective, separating clearly the physical model from the boundary conditions. This promotes reusability and the use of primitive physical models for assembling MEMS devices from primitive structures, based on the interconnection topology in generalized circuits. The physical modeling capabilities of Simscape have been used in the present work in order to develop a MEMS library containing parameterized fundamental building blocks (area and gap-varying MEMS capacitors, nonlinear springs, displacement stoppers, etc.) for the design, simulation and optimization of MEMS inertial sensors. The models capture both the nonlinear electromechanical interactions and geometrical nonlinearities and can be used for both small and large signal analyses, including the numerical computation of pull-in voltages (stability loss). Simscape behavioral modeling language was used for the implementation of reduced-order macro models, that present the advantage of a seamless interface with Simulink blocks, for creating hybrid information/energy flow system models. Test bench simulations of the library models compare favorably with both analytical results and with more in-depth finite element simulations performed in ANSYS. Separate MEMS-electronic integration tests were done on closed-loop MEMS accelerometers, where Simscape was used for modeling the MEMS device and Simulink for the electronic subsystem.

Keywords: across-through variables, electromechanical coupling, energy flow, information flow, Matlab/Simulink, MEMS, nonlinear, pull-in instability, reduced order macro models, Simscape

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689 Toxicity of Solenstemma Argel (Hargal ) on Nubian Goats

Authors: Amna B. Medani, M. A. Elbadwi Samia, Hassan A. Khalid

Abstract:

In our study, nine Nubian goat kids were obtained, allotted into three groups, and healthily adapted in pens within the premises of the Veterinary Teaching Hospital, University of Khartoum to be given the oral doses of the dried herb shoots at daily doses of 1 and 5 gm/kg/day with drinking water, while the kids of the control group were left undosed. All goats were slaughtered,if not died, after 35 days. S. argel at the given doses caused signs of arched posture, ruffled hair, shivering and paralysis of limbs. On post mortem, lesions were seen to be hepatic fatty changes, renal necrosis, congested lungs and inflamed intestines. Serum chemistry investigations revealed significant increase (P< 0.05-0.01) in the activities of ALP(alkaline phosphates) and AST( aspartate-aminotransferase) in goats dosed with 5 gm /kg/ day. Also observed were significant increases in inorganic phosphorus and urea concentrations (P < 0.05-0.01) in both dosed goat groups. .Other investigations including the activity of GGT( gamma glutamyltransferase), creatinine, calcium, total protein and albumin illustrated no significant difference from that of the undosed controls. On haematological evaluation , the goat kids dosed with 5 gm/kg/dayshowed a decrease in haemoglobin concentration and red blood cells count of (P < 0.05-0.01).Both groups of dosed goats showed a higher packed cell volume values of (P < 0.05) when compared to the control goats .Mean corpuscular haemoglobin values were not different from those of the control kids. S. argel at the given doses caused signs of arched posture, ruffled hair, shivering and paralysis of limbs. On post mortem, lesions were seen to be hepatic fatty changes, renal necrosis, congested lungs and inflamed intestines. Serum chemistry investigations revealed significant increase (P < 0.05-0.01) in the activities of ALP(alkaline phosphates) and AST( aspartate-aminotransferase) in goats dosed with 5 gm /kg/ day. Also observed were significant increases in inorganic phosphorus and urea concentrations (P < 0.05-0.01) in both dosed goat groups. .Other investigations including the activity of GGT( gamma-glutamyltransferase), creatinine, calcium, total protein and albumin illustrated no significant difference from that of the undosed controls. calcium, total protein and albumin illustrated no significant difference from that of the undosed controls. On haematological evaluation , the goat kids dosed with 5 gm/kg/dayshowed a decrease in haemoglobin concentration and red blood cells count of (P < 0.05-0.01).Both groups of dosed goats showed a higher packed cell volume values of (P < 0.05) when compared to the control goats .Mean corpuscular haemoglobin values were not different from those of the control kids. Data obtained were then discussed to find S. argel irritable to intestines , toxic to the kidney and liver and a haematological mild toxin.Suggestions for future were forwarded.

Keywords: hargal, nubian goats, solenstemma argel, toxicity

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688 Vitamin D Intoxication with Hypercalcemia Due to Overuse of Supplement

Authors: Sara Ataei, Mohammad Bagher Oghazian, Mania Radfar

Abstract:

We describe a patient with hypercalcemia associated with the injection of high doses vitamin D as supplement for a period of six months. A 76-year-old woman had been taking an intramuscular injection of vitamin D 300,000 IU every ten days for six months. She was hospitalized with symptoms of hypercalcemia: chronic constipation, unstable gait, a chronic generalized musculoskeletal pain and increased fatigue. On admission her 25 (OH) vitamin D and Calcium levels were 559 nmol/L and 13.85 mg/dL respectively, and Parathyroid Hormone (PTH) level was 7.1 pg/mL. Immediately she received diuresis therapy with saline and furosemide in conjunction with calcitonin and pamidronate. At discharge her serum calcium level was 11.5 mg/dL. To lower endogenous overproduction of calcitriol, prednisolone 20 mg/day for 10 days was administered at discharge time.

Keywords: vitamin D, hypercalcemia, vitamin D toxicity, parathyroid hormone

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