Analysis of machine elements in shape of helicoidal shell on cylindrical shell

2007 ◽  
Vol 221 (6) ◽  
pp. 627-638 ◽  
Author(s):  
S Savicevic ◽  
S Zekovic
Keyword(s):  
Differential Equation ◽  
Cylindrical Shell ◽  
Cross Section ◽  
Shell Thickness ◽  
Strength Criterion ◽  
Uniform Pressure ◽  
Machine Elements ◽  
The Finite Difference Method ◽  
Automated Determination

A procedure for the automated determination of the geometric parameters of a helicoidal shell on a cylindrical one that is applied to machines for special purposes is presented in this paper. A differential equation for the bending of a helicoidal shell subjected to a uniform pressure and a differential equation for the cylindrical shell loaded by a uniformly distributed moment along the helix are used to define the boundary conditions along the cross-section of these shells. The finite difference method is used to solve the differential equation for the bending of a helicoidal shell in MATLAB software. The values of the shell thickness are determined for different parameters using a strength criterion. Different models of the helicoidal shell are analysed.

On the Determination of the Centers of Twist and of Shear for Cylindrical Shell Beams

1972 ◽  
Vol 39 (4) ◽  
pp. 1098-1102 ◽  
Author(s):  
E. Reissner ◽  
W. T. Tsai
Keyword(s):  
Cylindrical Shell ◽  
Cross Section ◽  
Flat Plates ◽  
Influence Coefficients ◽  
Special Cases ◽  
Box Beams ◽  
Circular Cylindrical Shells ◽  
Definition Of ◽  
Open Cross Section

We consider the problem on the basis of a definition of the centers of shear and of twist in terms of influence coefficients for end-loaded cantilever beams. We determine the influence coefficients approximately by combining the Saint Venant torsion and flexure solutions with an appropriate version of the principle of minimum complementary energy. We apply this method, considering the beam as a cylindrical shell. We find among other things a formula for closed-cross-section shells which includes as special cases the strength-of-materials formula for open-cross-section shells, as well as a formula for variable-thickness flat plates. Problems of particular theoretical interest for which solutions are given concern rectangular box beams and circular cylindrical shells with circumferentially varying properties.

Stress Calculation for Large Storage Oil Tanks' Shells Based on the Theory of Short Cylindrical Shell

2012 ◽  
Vol 602-604 ◽  
pp. 2163-2169
Author(s):  
Yu Kun Li ◽  
Wen Hong Sun ◽  
Guan Duan ◽  
Jun Hui Liang
Keyword(s):  
Differential Equation ◽  
Finite Element ◽  
Cylindrical Shell ◽  
General Solution ◽  
Cross Section ◽  
Large Diameter ◽  
Element Calculation ◽  
Calculation Results ◽  
Stress And Deformation ◽  
Oil Tanks

This article adopts Krylov’s functions, getting a general solution of deflection differential equation of short cylindrical shell. Due to the general solution and continuity and smoothness conditions of shell’s deflection, detailed calculating formulas about deformation and stress of large diameter cylindrical shells with cross-section are obtained, whose solving process is realized by programming. Taking a running tank for example, the method deduced in this article calculates its deformation and stress. Compared with the FE (finite element) calculation results and the test data, this method calculates tank wall's stress and deformation accurately, which can be used to check the thickness of tank shell.

A quantitative approach to inner shell losses

1978 ◽  
Vol 36 (1) ◽  
pp. 526-527 ◽  
Author(s):  
R.D. Leapman ◽  
P. Rez ◽  
D.F. Mayers
Keyword(s):  
Energy Transfer ◽  
Cross Section ◽  
Cross Sections ◽  
Accurate Determination ◽  
Background Intensity ◽  
Core Excitation ◽  
Quantitative Basis ◽  
Cross Section Differential ◽  
Bound Electrons

Microanalysis by EELS has been developing rapidly and though the general form of the spectrum is now understood there is a need to put the technique on a more quantitative basis (1,2). Certain aspects important for microanalysis include: (i) accurate determination of the partial cross sections, σx(α,ΔE) for core excitation when scattering lies inside collection angle a and energy range ΔE above the edge, (ii) behavior of the background intensity due to excitation of less strongly bound electrons, necessary for extrapolation beneath the signal of interest, (iii) departures from the simple hydrogenic K-edge seen in L and M losses, effecting σx and complicating microanalysis. Such problems might be approached empirically but here we describe how computation can elucidate the spectrum shape.The inelastic cross section differential with respect to energy transfer E and momentum transfer q for electrons of energy E0 and velocity v can be written as

Profil Penyakit Malaria Di Rumah Sakit Islam Siti Rahmah Padang Tahun 2018

2020 ◽  
Vol 2 (2) ◽  
pp. 08-15
Author(s):  
Rahma Triyana ◽  
Salmi Salmi
Keyword(s):  
Observational Study ◽  
Frequency Distribution ◽  
Cross Section ◽  
Laboratory Tests ◽  
Age Group ◽  
Normal Range ◽  
Cross Sectional ◽  
West Sumatra ◽  
Severity Of The Disease

Malaria is one of the health problems in Indonesia, especially West Sumatra. Determination of the description of Malaria disease in an area is needed to determine the spread and severity of the disease. This study aims to determine the frequency distribution according to age, sex and place of residence, description of the types of Plasmodium causes of Malaria and hematological features in Malaria patients at Siti Rahmah Padang Hospital in 2018. This type of research is a descriptive observational study with an approach or design cross section (cross sectional). The frequency distribution of Malaria sufferers in Siti Rahmah Padang Hospital in 2018 according to the highest age was in the age group 21-30 years as many as 28 cases (36.8%), the highest sex among men was 46 (60.5%) and the highest number of residences was found in Koto Tangah sub-district there were 31 cases (40.8%). The type of Plasmodium found in Malaria cases in Siti Rahmah Padang Hospital in 2018 was P. vivax (73 cases (96.05%)) and P. falciparum (3 cases (3.95%)). The results of laboratory tests on Hb, hematocrit, platelet and leukocyte levels in Malaria positive patients in Siti Rahmah Padang Hospital in 2018 were in the normal range.

Profil Penyakit Malaria di Rumah Sakit Islam Siti Rahmah Padang Tahun 2018

2020 ◽  
Vol 2 (2) ◽  
pp. 08-15
Author(s):  
Rahma Triyana Y ◽  
Salmi Salmi
Keyword(s):  
Observational Study ◽  
Frequency Distribution ◽  
Cross Section ◽  
Laboratory Tests ◽  
Age Group ◽  
Normal Range ◽  
Cross Sectional ◽  
West Sumatra ◽  
Severity Of The Disease

Malaria is one of the health problems in Indonesia, especially West Sumatra. Determination of the description of Malaria disease in an area is needed to determine the spread and severity of the disease. This study aims to determine the frequency distribution according to age, sex and place of residence, description of the types of Plasmodium causes of Malaria and hematological features in Malaria patients at Siti Rahmah Padang Hospital in 2018. This type of research is a descriptive observational study with an approach or design cross section (cross sectional). The frequency distribution of Malaria sufferers in Siti Rahmah Padang Hospital in 2018 according to the highest age was in the age group 21-30 years as many as 28 cases (36.8%), the highest sex among men was 46 (60.5%) and the highest number of residences was found in Koto Tangah sub-district there were 31 cases (40.8%). The type of Plasmodium found in Malaria cases in Siti Rahmah Padang Hospital in 2018 was P. vivax (73 cases (96.05%)) and P. falciparum (3 cases (3.95%)). The results of laboratory tests on Hb, hematocrit, platelet and leukocyte levels in Malaria positive patients in Siti Rahmah Padang Hospital in 2018 were in the normal range.

An Automated Procedure for the Determination of Ammonia in Tobacco

1972 ◽  
Vol 6 (4) ◽  
Author(s):  
P.F. Collins ◽  
W.W. Lawrence ◽  
J.F. Williams
Keyword(s):  
Standard Deviation ◽  
Relative Standard Deviation ◽  
Distillation Method ◽  
Relative Standard ◽  
Tobacco Sample ◽  
Automated Determination

AbstractA procedure for the automated determination of ammonia in tobacco has been developed. Ammonia is extracted from the ground tobacco sample with water and is determined with a Technicon Auto Analyser system which employs separation of the ammonia through volatilization followed by colourimetry using the phenate-hypochlorite reaction. The procedure has been applied to a variety of tobaccos containing from 0.02 to 0.5 % ammonia with an overall relative standard deviation of 2 %. The accuracy of the procedure as judged by recovery tests and by comparison to a manual distillation method is considered adequate

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