Stresses at the Intersection of Sphere and Cylinder by a Variant Finite-Difference Method

1974 ◽  
Vol 41 (3) ◽  
pp. 744-752 ◽  
Author(s):  
Mustafa Hassan Fayed
Keyword(s):  
Finite Difference ◽  
The Body ◽  
Simultaneous Equations ◽  
Discrete Problem ◽  
Internal Point ◽  
Governing Equations ◽  
Finite Difference Technique ◽  
Taylor Series Expansions ◽  
Continuous Problem

The aim of this paper is the determination of stresses at the intersection of cylinder with the sphere using a variant finite-difference technique. Mesh lines are drawn on the cross section of the body which are roughly parallel and perpendicular to the boundary, and which the author calls natural meshes. Discretization of the governing differential equations must be carried out to reduce the continuous problem to a discrete problem, this discretization converts the problem into a set of linear simultaneous equations for the functions under consideration at a set of mesh points. The derivatives to be inserted in the governing equations and boundary conditions are found by writing Taylor series expansions at a point in terms of five neighboring points in the case where the point is an internal point (four for a boundary point). By an elimination process the derivatives can be eliminated for each point, and we are left with the unknown functions only.

On the Motion of Granular Materials Due to Shear

2000 ◽  
Author(s):  
Mehrdad Massoudi ◽  
Tran X. Phuoc
Keyword(s):  
Finite Difference ◽  
Granular Materials ◽  
Continuum Model ◽  
Theory Model ◽  
Governing Equations ◽  
Flat Plates ◽  
Material Parameters ◽  
Finite Difference Technique ◽  
Linear Differential ◽  
The Continuum

Abstract In this paper we study the flow of granular materials between two horisontal flat plates where the top plate is moving with a constant speed. The constitutive relation used for the stress is based on the continuum model proposed by Rajagopal and Massoudi (1990), where the material parameters are derived using the kinetic theory model proposed by Boyle and Massoudi (1990). The governing equations are non-dimensionalized and the resulting system of non-linear differential equations is solved numerically using finite difference technique.

Gender determination of caucasoid hair using image analysis

1993 ◽  
Vol 51 ◽  
pp. 216-217
Author(s):  
T.B. Ball ◽  
W.M. Hess
Keyword(s):  
Image Analysis ◽  
Cross Sections ◽  
Scalp Hair ◽  
The Body ◽  
Equivalent Diameter ◽  
Cross Sectional ◽  
Hair Samples ◽  
Length Width ◽  
Morphological Differences

It has been demonstrated that cross sections of bundles of hair can be effectively studied using image analysis. These studies can help to elucidate morphological differences of hair from one region of the body to another. The purpose of the present investigation was to use image analysis to determine whether morphological differences could be demonstrated between male and female human Caucasian terminal scalp hair.Hair samples were taken from the back of the head from 18 caucasoid males and 13 caucasoid females (Figs. 1-2). Bundles of 50 hairs were processed for cross-sectional examination and then analyzed using Prism Image Analysis software on a Macintosh llci computer. Twenty morphological parameters of size and shape were evaluated for each hair cross-section. The size parameters evaluated were area, convex area, perimeter, convex perimeter, length, breadth, fiber length, width, equivalent diameter, and inscribed radius. The shape parameters considered were formfactor, roundness, convexity, solidity, compactness, aspect ratio, elongation, curl, and fractal dimension.

Computer Simulation of the Response of Amperometric Biosensors in Stirred and non Stirred Solution

2003 ◽  
Vol 8 (1) ◽  
pp. 3-18 ◽  
Author(s):  
R. Baronas ◽  
F. Ivanauskas ◽  
J. Kulys
Keyword(s):  
Mathematical Model ◽  
Computer Simulation ◽  
Finite Difference ◽  
Mass Transport ◽  
Enzyme Reaction ◽  
Analyte Concentration ◽  
Amperometric Biosensors ◽  
Finite Difference Technique ◽  
Enzyme Layer ◽  
Biosensor Response

A mathematical model of amperometric biosensors has been developed to simulate the biosensor response in stirred as well as non stirred solution. The model involves three regions: the enzyme layer where enzyme reaction as well as mass transport by diffusion takes place, a diffusion limiting region where only the diffusion takes place, and a convective region, where the analyte concentration is maintained constant. Using computer simulation the influence of the thickness of the enzyme layer as well the diffusion one on the biosensor response was investigated. The computer simulation was carried out using the finite difference technique.

Modelling of Moisture Movement in Wood during Outdoor Storage

2001 ◽  
Vol 6 (2) ◽  
pp. 3-14 ◽  
Author(s):  
R. Baronas ◽  
F. Ivanauskas ◽  
I. Juodeikienė ◽  
A. Kajalavičius
Keyword(s):  
Experimental Data ◽  
Finite Difference ◽  
Climatic Conditions ◽  
Two Dimensional ◽  
Moisture Movement ◽  
Finite Difference Technique ◽  
Long Term Storage ◽  
Space Formulation ◽  
Term Storage

A model of moisture movement in wood is presented in this paper in a two-dimensional-in-space formulation. The finite-difference technique has been used in order to obtain the solution of the problem. The model was applied to predict the moisture content in sawn boards from pine during long term storage under outdoor climatic conditions. The satisfactory agreement between the numerical solution and experimental data was obtained.

Determination of Lead Content in Red Colored Lipsticks from Mandalay Market by Flame Atomic Absorption Spectrophotometer

2018 ◽  
Vol 30 (3) ◽  
pp. 167-173
Keyword(s):  
Sampling Procedure ◽  
The Body ◽  
Lead Content ◽  
Social Psychological ◽  
Allowable Limit ◽  
Flame Atomic Absorption ◽  
Therapeutic Benefits ◽  
Flame Atomic Absorption Spectrophotometer ◽  
Exposure Levels

Red colored lipstick is the most widely used cosmetic product. Although lipstick gives a lot of social, psychological and therapeutic benefits, it may harm the consumers. Because some lipsticks contain a considerable amount of heavy metal especially lead. Lead is being used in lipstick mainly for the pigments required to obtain needed colors. Lead accumulates in the body over time and lead-containing lipstick applied several times a day, every day, combined with lead in water and other sources, could add up to significant exposure levels. Therefore, this study was aimed to determine lead content in red colored lipsticks from market. This study was laboratorybased, analytical study by using 25 lipstick samples. Red colored lipsticks were bought from Mandalay Market by random sampling procedure and they were completely coded to avoid the bias. Then, lead content in coded samples was determined by Flame AAS according to International Conference on Harmonization (ICH) guideline. Lead contents of 88% of the lipsticks samples were more than specified limit (20 ppm) of Food and Drug Administration, United States. All of them, lead content was highest in counterfeit lipsticks group. Among the tested lipstick samples, lipstick with lowest lead content was LE-RL 01 (15.74 ppm) and the lipstick with highest lead content was CF-RL 01(60.09 ppm). In conclusion, lead contents of red colored lipsticks (22 out of 25) from market samples were higher than allowable limit (20 ppm).

Fast Method for the Determination of Residual Solvents in Radiopharmaceutical Products

2017 ◽  
Vol 68 (4) ◽  
pp. 666-670 ◽  
Author(s):  
Mirela Mihon ◽  
Catalin Stelian Tuta ◽  
Alina Catrinel Ion ◽  
Dana Niculae ◽  
Vasile Lavric
Keyword(s):  
Gas Chromatography ◽  
Control Method ◽  
Limit Of Detection ◽  
The Body ◽  
Biologically Active ◽  
Injection Technique ◽  
Fast Method ◽  
Residual Solvent ◽  
Residual Solvents

The aim of this work was the development and validation of a fast analytical method to determine the residual solvents content in radiopharmaceuticals such as: 18F-Fluorodeoxyglucose (18F-FDG), 18F-Fluoroestradiol (18F-FES), 18F-Fluorothymidine (18F-FLT),18F-Fluoromisonidazole (18F-FMISO). Radiopharmaceuticals are radioactive preparations for medical purposes used in nuclear medicine as tracers in diagnostic imaging and treatment of certain diseases. Positron Emission Tomography (PET) is a medical imaging technique that consists in introducing into the body of a small amount of a biologically active chemical compound labelled with a short lived positron-emitting radioisotope (18F, 11C, 68Ga). Residual solvents are critical impurities in radiopharmaceuticals that can affect labelling, stability and physicochemical properties of drugs. Therefore, the determination of these solvents is essential for quality control of radiopharmaceuticals. Validation of the control method for residual solvents by gas chromatography is referred by the European Pharmacopoeia using a special injection technique (head space). The parameters of the method, which comply with International Conference on Harmonization guidelines, are: accuracy, precision, linearity, limit of detection, limit of quantification and robustness. The proposed method (direct gas chromatography injection) proved to be linear, precise, accurate and robust. Good linearity was achieved for all the solvents and correlation coefficients (R2) for each residual solvent were found more than 0.99.

scholarly journals Simultaneous Estimation of Domperidone and Pantoprazole in Solid Dosage Form by UV Spectrophotometry

2006 ◽  
Vol 3 (3) ◽  
pp. 142-145
Author(s):  
P. Ravi Kumar ◽  
P. Bhanu Prakash ◽  
M. Murali Krishna ◽  
M. Santha Yadav ◽  
C. Asha Deepthi
Keyword(s):  
Simultaneous Equation ◽  
Simultaneous Equations ◽  
Simultaneous Estimation ◽  
Uv Spectrophotometry ◽  
Q Value ◽  
Value Analysis ◽  
Spectrophotometric Methods ◽  
Solid Dosage ◽  
Tablet Dosage

Domperidone is an antiemetic and pantoprazole is an antiulcer drug. Simple, precise, rapid and selective simultaneous equation and Q- analysis UV spectrophotometric methods have been developed for the simultaneous determination of domperidone and pantoprazole from combined tablet dosage forms. The methods involve solving of simultaneous equations and Q-value analysis based on measurement absorptivity at 216, 287 and 290 nm respectively. Linearity lies between 1-15 mcg/mL for domperidone and 0-50 mcg/mL for pantoprazole.

Determination of an impulsive diffusion operator from interior spectral data

Analysis ◽  
2020 ◽  
Vol 40 (1) ◽  
pp. 39-45
Author(s):  
Yasser Khalili ◽  
Dumitru Baleanu
Keyword(s):  
Inverse Problem ◽  
Spectral Data ◽  
Potential Functions ◽  
Half Line ◽  
Internal Point ◽  
Diffusion Operator ◽  
Impulsive Diffusion

AbstractIn the present work, the interior spectral data is used to investigate the inverse problem for a diffusion operator with an impulse on the half line. We show that the potential functions {q_{0}(x)} and {q_{1}(x)} can be uniquely established by taking a set of values of the eigenfunctions at some internal point and one spectrum.

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