Search results for: Best candidates method
7976 Significance of Splitting Method in Non-linear Grid system for the Solution of Navier-Stokes Equation
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Solution to unsteady Navier-Stokes equation by Splitting method in physical orthogonal algebraic curvilinear coordinate system, also termed 'Non-linear grid system' is presented. The linear terms in Navier-Stokes equation are solved by Crank- Nicholson method while the non-linear term is solved by the second order Adams-Bashforth method. This work is meant to bring together the advantage of Splitting method as pressure-velocity solver of higher efficiency with the advantage of consuming Non-linear grid system which produce more accurate results in relatively equal number of grid points as compared to Cartesian grid. The validation of Splitting method as a solution of Navier-Stokes equation in Nonlinear grid system is done by comparison with the benchmark results for lid driven cavity flow by Ghia and some case studies including Backward Facing Step Flow Problem.
Keywords: Navier-Stokes, 'Non-linear grid system', Splitting method.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 15307975 A Comparative Study on the Creativity of Organizations in Office Management and Secretarial Work and the Assessment of Creativity among Students Training in This Field
Authors: Mehmet Altınöz
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Today, the working areas put forward the administration of change. In order to provide this; it is required from the organizations to be creative. Professional creativity in offices depends on an environment that enables the development of the organization only after the individual or collective exertions within the organization. By providing this environment, the organization will gain efficiency, productivity, and work pleasure. In order to bring up the workforce appropriate to the related expectations, the professional creativity of the office management and secretarial profession candidates should be evaluated, education programs appropriate to this and related directly with the service quality should be prepared and the future of this profession should be directed. The aim of this study is to ensure the attention to improve the prepared education program as well as the creative thoughts and their applications, when carrying out an office management and secretarial training. 144 students took place in this research and a questionnaire of 48 questions was carried out.
Keywords: Creativity, professional creativity, creativity evaluation, office management, secretarial
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 12047974 A Novel Method for the Characterization of Synchronization and Coupling in Multichannel EEG and ECoG
Authors: Manfred Hartmann, Andreas Graef, Hannes Perko, Christoph Baumgartner, Tilmann Kluge
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In this paper we introduce a novel method for the characterization of synchronziation and coupling effects in multivariate time series that can be used for the analysis of EEG or ECoG signals recorded during epileptic seizures. The method allows to visualize the spatio-temporal evolution of synchronization and coupling effects that are characteristic for epileptic seizures. Similar to other methods proposed for this purpose our method is based on a regression analysis. However, a more general definition of the regression together with an effective channel selection procedure allows to use the method even for time series that are highly correlated, which is commonly the case in EEG/ECoG recordings with large numbers of electrodes. The method was experimentally tested on ECoG recordings of epileptic seizures from patients with temporal lobe epilepsies. A comparision with the results from a independent visual inspection by clinical experts showed an excellent agreement with the patterns obtained with the proposed method.Keywords: EEG, epilepsy, regression analysis, seizurepropagation.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 14387973 Development of Variable Stepsize Variable Order Block Method in Divided Difference Form for the Numerical Solution of Delay Differential Equations
Authors: Fuziyah Ishak, Mohamed B. Suleiman, Zanariah A. Majid, Khairil I. Othman
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This paper considers the development of a two-point predictor-corrector block method for solving delay differential equations. The formulae are represented in divided difference form and the algorithm is implemented in variable stepsize variable order technique. The block method produces two new values at a single integration step. Numerical results are compared with existing methods and it is evident that the block method performs very well. Stability regions of the block method are also investigated.Keywords: block method, delay differential equations, predictor-corrector, stability region, variable stepsize variable order.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 14827972 pH-Responsiveness Properties of a Biodigradable Hydrogels Based on Carrageenan-g-poly(NaAA-co-NIPAM)
Authors: Mohammad Sadeghi, Behrouz Heidari, Korush Montazeri
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A novel thermo-sensitive superabsorbent hydrogel with salt- and pH-responsiveness properties was obtained by grafting of mixtures of acrylic acid (AA) and N-isopropylacrylamide (NIPAM) monomers onto kappa-carrageenan, kC, using ammonium persulfate (APS) as a free radical initiator in the presence of methylene bisacrylamide (MBA) as a crosslinker. Infrared spectroscopy was carried out to confirm the chemical structure of the hydrogel. Moreover, morphology of the samples was examined by scanning electron microscopy (SEM). The effect of MBA concentration and AA/NIPAM weight ratio on the water absorbency capacity has been investigated. The swelling variations of hydrogels were explained according to swelling theory based on the hydrogel chemical structure. The hydrogels exhibited salt-sensitivity and cation exchange properties. The temperature- and pH-reversibility properties of the hydrogels make the intelligent polymers as good candidates for considering as potential carriers for bioactive agents, e.g. drugs.Keywords: superabsorbent, carrageenan, acrylic acid, Nisopropylacrylamide, hydrogel, swelling
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 16767971 An Efficient Segmentation Method Based on Local Entropy Characteristics of Iris Biometrics
Authors: Ali Shojaee Bakhtiari, Ali Asghar Beheshti Shirazi, Amir Sepasi Zahmati
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An efficient iris segmentation method based on analyzing the local entropy characteristic of the iris image, is proposed in this paper and the strength and weaknesses of the method are analyzed for practical purposes. The method shows special strength in providing designers with an adequate degree of freedom in choosing the proper sections of the iris for their application purposes.Keywords: Iris segmentation, entropy, biocryptosystem, biometric identification.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 14337970 A Novel Eccentric Lapping Method with Two Rotatable Lapping Plates for Finishing Cemented Carbide Balls
Authors: C. C. Lv, Y. L. Sun, D. W. Zuo
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Cemented carbide balls are usually implemented in industry under the environment of high speed, high temperature, corrosiveness and strong collisions. However, its application is limited due to high fabrication cost, processing efficiency and quality. A novel eccentric lapping method with two rotatable lapping plates was proposed in this paper. A mathematical model was constructed to analyze the influence of each design parameter on this lapping method. To validate this new lapping method, an orthogonal experiment was conducted with cemented carbide balls (YG6). The simulation model was verified and the optimal lapping parameters were derived. The results show that the surface roundness of the balls reaches to 0.65um from 2um in 1 hour using this lapping method. So, using this novel lapping method, it can effectively improve the machining precision and efficiency of cemented carbide balls.
Keywords: Cemented carbide balls, eccentric lapping, high precision, lapping tracks, V-groove.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 25237969 Radiation Heat Transfer Effect in Solid Oxide Fuel Cell: Application of the Lattice Boltzmann Method
Authors: Imen Mejri, Ahmed Mahmoudi, Mohamed A. Abbassi, Ahmed Omri
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The radiation effect within the solid anode, electrolyte, and cathode SOFC layers problem has been investigated in this paper. Energy equation is solved by the Lattice Boltzmann method (LBM). The Rosseland method is used to model the radiative transfer in the electrodes. The Schuster-Schwarzschild method is used to model the radiative transfer in the electrolyte. Without radiative effect, the found results are in good agreement with those published. The obtained results show that the radiative effect can be neglected.
Keywords: SOFC, lattice Boltzmann method, conduction, radiation.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 24547968 Dynamics and Feedback Control for a New Hyperchaotic System
Authors: Kejun Zhuang, Hailong Zhu
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In this paper, stability and Hopf bifurcation analysis of a novel hyperchaotic system are investigated. Four feedback control strategies, the linear feedback control method, enhancing feedback control method, speed feedback control method and delayed feedback control method, are used to control the hyperchaotic attractor to unstable equilibrium. Moreover numerical simulations are given to verify the theoretical results.Keywords: Feedback control, Hopf bifurcation, hyperchaotic system, stability.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 17667967 The Method of Evaluation Artery Diameter from Ultrasound Video
Authors: U. Rubins, Z. Marcinkevics, K.Volceka
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The cardiovascular system has become the most important subject of clinical research, particularly measurement of arterial blood flow. Therefore correct determination of arterial diameter is crucial. We propose a novel, semi-automatic method for artery lumen detection. The method is based on Gaussian probability function. Usability of our proposed method was assessed by analyzing ultrasound B-mode CFA video sequences acquired from eleven healthy volunteers. The correlation coefficient between the manual and semi-automatic measurement of arterial diameter was 0.996. Our proposed method for detecting artery boundary is novel and accurate enough for the measurement of artery diameter.Keywords: Ultrasound, boundary detection, artery diameter, curve fitting.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 15977966 Generalized Chebyshev Collocation Method
Authors: Junghan Kim, Wonkyu Chung, Sunyoung Bu, Philsu Kim
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In this paper, we introduce a generalized Chebyshev collocation method (GCCM) based on the generalized Chebyshev polynomials for solving stiff systems. For employing a technique of the embedded Runge-Kutta method used in explicit schemes, the property of the generalized Chebyshev polynomials is used, in which the nodes for the higher degree polynomial are overlapped with those for the lower degree polynomial. The constructed algorithm controls both the error and the time step size simultaneously and further the errors at each integration step are embedded in the algorithm itself, which provides the efficiency of the computational cost. For the assessment of the effectiveness, numerical results obtained by the proposed method and the Radau IIA are presented and compared.
Keywords: Generalized Chebyshev Collocation method, Generalized Chebyshev Polynomial, Initial value problem.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 26437965 An Improved Algorithm for Calculation of the Third-order Orthogonal Tensor Product Expansion by Using Singular Value Decomposition
Authors: Chiharu Okuma, Naoki Yamamoto, Jun Murakami
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As a method of expanding a higher-order tensor data to tensor products of vectors we have proposed the Third-order Orthogonal Tensor Product Expansion (3OTPE) that did similar expansion as Higher-Order Singular Value Decomposition (HOSVD). In this paper we provide a computation algorithm to improve our previous method, in which SVD is applied to the matrix that constituted by the contraction of original tensor data and one of the expansion vector obtained. The residual of the improved method is smaller than the previous method, truncating the expanding tensor products to the same number of terms. Moreover, the residual is smaller than HOSVD when applying to color image data. It is able to be confirmed that the computing time of improved method is the same as the previous method and considerably better than HOSVD.
Keywords: Singular value decomposition (SVD), higher-orderSVD (HOSVD), outer product expansion, power method.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 16947964 Lagrangian Method for Solving Unsteady Gas Equation
Authors: Amir Taghavi, kourosh Parand, Hosein Fani
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In this paper we propose, a Lagrangian method to solve unsteady gas equation which is a nonlinear ordinary differential equation on semi-infnite interval. This approach is based on Modified generalized Laguerre functions. This method reduces the solution of this problem to the solution of a system of algebraic equations. We also compare this work with some other numerical results. The findings show that the present solution is highly accurate.
Keywords: Unsteady gas equation, Generalized Laguerre functions, Lagrangian method, Nonlinear ODE.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 15397963 Generation of Numerical Data for the Facilitation of the Personalized Hyperthermic Treatment of Cancer with An Interstital Antenna Array Using the Method of Symmetrical Components
Authors: Prodromos E. Atlamazoglou
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The method of moments combined with the method of symmetrical components is used for the analysis of interstitial hyperthermia applicators. The basis and testing functions are both piecewise sinusoids, qualifying our technique as a Galerkin one. The dielectric coatings are modeled by equivalent volume polarization currents, which are simply related to the conduction current distribution, avoiding in that way the introduction of additional unknowns or numerical integrations. The results of our method for a four dipole circular array, are in agreement with those already published in literature for a same hyperthermia configuration. Apart from being accurate, our approach is more general, more computationally efficient and takes into account the coupling between the antennas.Keywords: Hyperthermia, integral equations, insulated antennas, method of symmetrical components.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 6987962 Extend Three-wave Method for the (3+1)-Dimensional Soliton Equation
Authors: Somayeh Arbabi Mohammad-Abadi, Maliheh Najafi
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In this paper, we study (3+1)-dimensional Soliton equation. We employ the Hirota-s bilinear method to obtain the bilinear form of (3+1)-dimensional Soliton equation. Then by the idea of extended three-wave method, some exact soliton solutions including breather type solutions are presented.
Keywords: Three-wave method, (3+1)-dimensional Soliton equation, Hirota's bilinear form.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 15727961 Application of Four-electrode Method to Analysis Resistance Characteristics of Conductive Concrete
Authors: Chun-Yao Lee, Siang-Ren Wang
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The purpose of this paper is to discuss the influence of resistance characteristic on the high conductive concrete considering the various voltage and environment. The four-electrode method is applied to the tailor-made high conductive concrete with appropriate proportion. The curve of resistivity with the changes of voltage and environment is plotted and the changes of resistivity are explored. The result based on the methods reveals that resistivity is less affected by the temperature factor, and the four-electrode method would be an applicable measurement method on a site inspection.Keywords: Conductive concrete, Resistivity.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 16067960 Improvement of MLLR Speaker Adaptation Using a Novel Method
Authors: Ing-Jr Ding
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This paper presents a technical speaker adaptation method called WMLLR, which is based on maximum likelihood linear regression (MLLR). In MLLR, a linear regression-based transform which adapted the HMM mean vectors was calculated to maximize the likelihood of adaptation data. In this paper, the prior knowledge of the initial model is adequately incorporated into the adaptation. A series of speaker adaptation experiments are carried out at a 30 famous city names database to investigate the efficiency of the proposed method. Experimental results show that the WMLLR method outperforms the conventional MLLR method, especially when only few utterances from a new speaker are available for adaptation.Keywords: hidden Markov model, maximum likelihood linearregression, speech recognition, speaker adaptation.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 18447959 Homogeneous and Heterogeneous Catalysis: Teachings of the Thermal Energy and Power Engineering Course
Authors: Junjie Chen
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It is usually difficult for students to understand some basic theories in learning thermal energy and power engineering course. A new teaching method was proposed that we should introduce the comparison research method of those theories to help them being understood. “Homogeneous and heterogeneous catalysis” teaching is analyzed as an example by comparison research method.
Keywords: Homogeneous catalysis, heterogeneous catalysis, thermal energy and power engineering, teaching method, comparison research method.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 55907958 A Fully Implicit Finite-Difference Solution to One Dimensional Coupled Nonlinear Burgers’ Equations
Authors: Vineet K. Srivastava, Mukesh K. Awasthi, Mohammad Tamsir
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A fully implicit finite-difference method has been proposed for the numerical solutions of one dimensional coupled nonlinear Burgers’ equations on the uniform mesh points. The method forms a system of nonlinear difference equations which is to be solved at each iteration. Newton’s iterative method has been implemented to solve this nonlinear assembled system of equations. The linear system has been solved by Gauss elimination method with partial pivoting algorithm at each iteration of Newton’s method. Three test examples have been carried out to illustrate the accuracy of the method. Computed solutions obtained by proposed scheme have been compared with analytical solutions and those already available in the literature by finding L2 and L∞ errors.
Keywords: Burgers’ equation, Implicit Finite-difference method, Newton’s method, Gauss elimination with partial pivoting.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 59517957 Development of Decision Support System for House Evaluation and Purchasing
Authors: Chia-Yu Hsu, Julaimin Goh, Pei-Chann Chang
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Home is important for Chinese people. Because the information regarding the house attributes and surrounding environments is incomplete in most real estate agency, most house buyers are difficult to consider the overall factors effectively and only can search candidates by sorting-based approach. This study aims to develop a decision support system for housing purchasing, in which surrounding facilities of each house are quantified. Then, all considered house factors and customer preferences are incorporated into Simple Multi-Attribute Ranking Technique (SMART) to support the housing evaluation. To evaluate the validity of proposed approach, an empirical study was conducted from a real estate agency. Based on the customer requirement and preferences, the proposed approach can identify better candidate house with consider the overall house attributes and surrounding facilities.Keywords: decision support system, real estate, decision analysis, housing evaluation, SMART
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 22077956 On a Pitch Duration Technique for Prosody Control
Authors: JongKuk Kim, HernSoo Hahn, Uei-Joong Yoo, MyungJin Bae
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In this paper, we propose a method of alter duration in frequency domain that control prosody in real time after pitch alteration. If there has a method to alteration duration freely among prosody information, that may used in several fields such as speech impediment person's pronunciation proof reading or language study. The pitch alteration method used control prosody altered by PSOLA synthesis method which is in time domain processing method. However, the duration of pitch alteration speech is changed by the frequency domain. In this paper, we altered the duration with the method of duration alteration by Fast Fourier Transformation in frequency domain. Consequently, the intelligibility of the pitch and duration are controlled has a slight decrease than the case when only pitch is changed, but the proposed algorithm obtained the higher MOS score about naturalness.Keywords: PSOLA, Pitch Alteration, Duration Control.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 16937955 On the Solution of Fully Fuzzy Linear Systems
Authors: Hsuan-Ku Liu
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A linear system is called a fully fuzzy linear system (FFLS) if quantities in this system are all fuzzy numbers. For the FFLS, we investigate its solution and develop a new approximate method for solving the FFLS. Observing the numerical results, we find that our method is accurate than the iterative Jacobi and Gauss- Seidel methods on approximating the solution of FFLS.
Keywords: Fully fuzzy linear equations, iterative method, homotopy perturbation method, approximate solutions.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 17567954 Continuity of Defuzzification and Its Application to Fuzzy Control
Authors: Takashi Mitsuishi, Kiyoshi Sawada, Yasunari Shidama
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The mathematical framework for studying of a fuzzy approximate reasoning is presented in this paper. Two important defuzzification methods (Area defuzzification and Height defuzzification) besides the center of gravity method which is the best well known defuzzification method are described. The continuity of the defuzzification methods and its application to a fuzzy feedback control are discussed.
Keywords: Fuzzy approximate reasoning, defuzzification, area method, height method.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 16807953 Rural Connectivity Technologies Cost Analysis
Authors: F. Simba, L. Trojer, N.H. Mvungi, B.M. Mwinyiwiwa, E.M. Mjema
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Rural areas of Tanzania are still disadvantaged in terms of diffusion of IP-based services; this is due to lack of Information and Communication Technology (ICT) infrastructures, especially lack of connectivity. One of the limitations for connectivity problems in rural areas of Tanzania is the high cost to establish infrastructures for IP-based services [1-2]. However the cost of connectivity varies from one technology to the other and at the same time, the cost is also different from one operator (service provider) to another within the country. This paper presents development of software system to calculate cost of connectivity to rural areas of Tanzania. The system is developed to make an easy access of connectivity cost from different technologies and different operators. The development of the calculator follows the V-model software development lifecycle. The calculator is used to evaluate the economic viability of different technologies considered as being potential candidates to provide rural connectivity. In this paper, the evaluation is based on the techno-economic analysis approach.
Keywords: rural, connectivity, cost, V-model, techno economic analysis.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 19047952 Convergence and Comparison Theorems of the Modified Gauss-Seidel Method
Authors: Zhouji Chen
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In this paper, the modified Gauss-Seidel method with the new preconditioner for solving the linear system Ax = b, where A is a nonsingular M-matrix with unit diagonal, is considered. The convergence property and the comparison theorems of the proposed method are established. Two examples are given to show the efficiency and effectiveness of the modified Gauss-Seidel method with the presented new preconditioner.
Keywords: Preconditioned linear system, M-matrix, Convergence, Comparison theorem.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 15107951 Method Development and Validation for the Determination of Cefixime in Pure and Commercial Dosage Forms by Specrophotometry
Authors: S. N. H. Azmi, B. Iqbal, J. K. Al Mamari, K. A. Al Hattali, W. N. Al Hadhrami
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A simple, accurate and precise direct spectrophotometric method has been developed for the determination of cefixime in tablets and capsules. The method is based on the reaction of cefixime with a mixture of potassium iodide and potassium iodate to form yellow coloured product in ethanol-distilled water medium at room temperature which absorbed maximally at 352 nm. The factors affecting the reaction product were carefully studied and optimized. The validation parameters based on International Conference on Harmonisation (ICH, USA) guidelines were followed. The effect of common excipients used as additives has been tested and the tolerance limit was calculated for the determination of cefixime. Beer’s law is obeyed in the concentration range of 4 – 24 ug mL-1 with apparent molar absorptivity of 1.52 × 104 L mol-1cm-1 and Sandell’s sensitivity of 0.033 ug/cm2/ 0.001 absorbance unit. The limits of detection and quantitation for the proposed method are 0.32 and 1.06 ug mL-1, respectively. The proposed method has been successfully applied for the determination of cefixime in pharmaceutical formulations. The results obtained by the proposed method were statistically compared with the reference method using t- and F- values and found no significant difference between the two methods. The proposed method can be used as an alternate method for routine quality control analysis of cefixime in pharmaceutical formulations.
Keywords: Spectrophotometry, cefixime, validation, pharmaceutical formulations.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 31677950 A Semi-Implicit Phase Field Model for Droplet Evolution
Authors: M. H. Kazemi, D. Salac
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A semi-implicit phase field method for droplet evolution is proposed. Using the phase field Cahn-Hilliard equation, we are able to track the interface in multiphase flow. The idea of a semi-implicit finite difference scheme is reviewed and employed to solve two nonlinear equations, including the Navier-Stokes and the Cahn-Hilliard equations. The use of a semi-implicit method allows us to have larger time steps compared to explicit schemes. The governing equations are coupled and then solved by a GMRES solver (generalized minimal residual method) using modified Gram-Schmidt orthogonalization. To show the validity of the method, we apply the method to the simulation of a rising droplet, a leaky dielectric drop and the coalescence of drops. The numerical solutions to the phase field model match well with existing solutions over a defined range of variables.
Keywords: Coalescence, leaky dielectric, numerical method, phase field, rising droplet, semi-implicit method.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 8827949 The BGMRES Method for Generalized Sylvester Matrix Equation AXB − X = C and Preconditioning
Authors: Azita Tajaddini, Ramleh Shamsi
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In this paper, we present the block generalized minimal residual (BGMRES) method in order to solve the generalized Sylvester matrix equation. However, this method may not be converged in some problems. We construct a polynomial preconditioner based on BGMRES which shows why polynomial preconditioner is superior to some block solvers. Finally, numerical experiments report the effectiveness of this method.Keywords: Linear matrix equation, Block GMRES, matrix Krylov subspace, polynomial preconditioner.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 8817948 Physiological Effects on Scientist Astronaut Candidates: Hypobaric Training Assessment
Authors: Pedro Llanos, Diego García
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This paper is addressed to expanding our understanding of the effects of hypoxia training on our bodies to better model its dynamics and leverage some of its implications and effects on human health. Hypoxia training is a recommended practice for military and civilian pilots that allow them to recognize their early hypoxia signs and symptoms, and Scientist Astronaut Candidates (SACs) who underwent hypobaric hypoxia (HH) exposure as part of a training activity for prospective suborbital flight applications. This observational-analytical study describes physiologic responses and symptoms experienced by a SAC group before, during and after HH exposure and proposes a model for assessing predicted versus observed physiological responses. A group of individuals with diverse Science Technology Engineering Mathematics (STEM) backgrounds conducted a hypobaric training session to an altitude up to 22,000 ft (FL220) or 6,705 meters, where heart rate (HR), breathing rate (BR) and core temperature (Tc) were monitored with the use of a chest strap sensor pre and post HH exposure. A pulse oximeter registered levels of saturation of oxygen (SpO2), number and duration of desaturations during the HH chamber flight. Hypoxia symptoms as described by the SACs during the HH training session were also registered. This data allowed to generate a preliminary predictive model of the oxygen desaturation and O2 pressure curve for each subject, which consists of a sixth-order polynomial fit during exposure, and a fifth or fourth-order polynomial fit during recovery. Data analysis showed that HR and BR showed no significant differences between pre and post HH exposure in most of the SACs, while Tc measures showed slight but consistent decrement changes. All subjects registered SpO2 greater than 94% for the majority of their individual HH exposures, but all of them presented at least one clinically significant desaturation (SpO2 < 85% for more than 5 seconds) and half of the individuals showed SpO2 below 87% for at least 30% of their HH exposure time. Finally, real time collection of HH symptoms presented temperature somatosensory perceptions (SP) for 65% of individuals, and task-focus issues for 52.5% of individuals as the most common HH indications. 95% of the subjects experienced HH onset symptoms below FL180; all participants achieved full recovery of HH symptoms within 1 minute of donning their O2 mask. The current HH study performed on this group of individuals suggests a rapid and fully reversible physiologic response after HH exposure as expected and obtained in previous studies. Our data showed consistent results between predicted versus observed SpO2 curves during HH suggesting a mathematical function that may be used to model HH performance deficiencies. During the HH study, real-time HH symptoms were registered providing evidenced SP and task focusing as the earliest and most common indicators. Finally, an assessment of HH signs of symptoms in a group of heterogeneous, non-pilot individuals showed similar results to previous studies in homogeneous populations of pilots.
Keywords: Altitude sickness, cabin pressure, hypobaric chamber training, symptoms and altitude, slow onset hypoxia.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 4197947 In silico Studies on Selected Drug Targets for Combating Drug Resistance in Plasmodium falcifarum
Authors: D. Bhaskar, N. R. Wadehra, M. Gulati, A. Narula, R. Vishnu, G. Katyal
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With drug resistance becoming widespread in Plasmodium falciparum infections, the development of the alternative drugs is the desired strategy for prevention and cure of malaria. Three drug targets were selected to screen promising drug molecules from the GSK library of 13469 molecules. Using an in silico structure-based drug designing approach, the differences in binding energies of the substrate and inhibitor were exploited between target sites of parasite and human to design a drug molecule against Plasmodium. The docking studies have shown several promising molecules from GSK library with more effective binding as compared to the already known inhibitors for the drug targets. Though stronger interaction has been shown by several molecules as compared to the reference, few molecules have shown the potential as drug candidates though in vitro studies are required to validate the results. In case of thymidylate synthase-dihydrofolatereductase (TS-DHFR), three compounds have shown promise for future studies as potential drugs.
Keywords: Drug resistance, Drug targets, In silico studies, Plasmodium falciparum.
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