The R/S System: A New and Simple Approach to Determining Ligand Priority and a Unified Method for the Assignment and Correlation of Stereogenic Center Configuration in Diverse Stereoformulas

2000 ◽  
Vol 77 (7) ◽  
pp. 866 ◽  
Author(s):  
Dipak K. Mandal
Keyword(s):  
Simple Approach ◽  
System A ◽  
Center Configuration ◽  
Stereogenic Center ◽  
Unified Method

The Effect of Restraint Non-Linearity on the Instability of Growth of a Circumferential Through-Wall Crack in a Piping System

2002 ◽  
Author(s):  
E. Smith
Keyword(s):  
Simple Model ◽  
Crack Growth ◽  
Simple Approach ◽  
Instability Criterion ◽  
Piping System ◽  
Unstable Crack ◽  
Pipe Length ◽  
Unstable Crack Growth ◽  
System A ◽  
Linear Manner

The paper is concerned with the criterion for the instability of growth of a circumferential through-wall crack in a piping system. A simple approach involves representing the cracked section behaviour by a moment (M)–rotation (φ) relation. The criterion for unstable crack growth is then L* > EI |dφ/dM| where E is Young’s modulus and I is the second moment of area of the piping at the cracked section. L* can be viewed as a crack-system compliance length parameter or an “effective” pipe length. If the piping system, apart from the cracked system, behaves in a linear manner, L* is dependent on the system’s characteristics but most importantly, is independent of the magnitudes of any applied loadings and the characteristics of the cracked section. This paper is concerned with the effect of system non-linearity, and in particular restraint non-linearity, on the instability criterion, the considerations being based on the analyses of a simple model which contains a restraint which behaves non-linearly. In this case, we show that L* is no longer dependent only on the system’s characteristics, as is the case when the restraint behaves linearly.

scholarly journals Simple-Box-9 Coil System: A Novel Approach to Design of a Square Coil System for Producing Uniform Magnetic Fields

2010 ◽  
Vol 670 ◽  
pp. 275-283 ◽  
Author(s):  
Kunihisa Tashiro ◽  
Akihito Matsuoka ◽  
Hiroyuki Wakiwaka
Keyword(s):  
Magnetic Fields ◽  
Design Method ◽  
Simple Approach ◽  
Numerical Calculations ◽  
Side Length ◽  
Structure System ◽  
Coil System ◽  
System A ◽  
Fourth Part ◽  
Novel Approach

This paper presents a novel approach for the design of square coil system, through considerations of a conventional square coil system. This simple approach allows us to design a coil system which contains a greater number of coils. From this design method, we introduce a new structure system of same-sized square coils, Simple-Box-9. The constant coil spacing is a fourth-part of the side length of the coil, and the number of windings is 2/1/1/1/1/1/1/1/2. From numerical calculations and experiments, it is shown that Simple-Box-9 can achieve the best uniformity compared with conventional square coil systems.

A software error detection system - A simple approach in a complex aerospace environment

1981 ◽  
Author(s):  
L. COLLINS ◽  
D. CASEY ◽  
R. NIMENSKY ◽  
G. MERKES ◽  
C.-J. CHEN
Keyword(s):  
Error Detection ◽  
Detection System ◽  
Simple Approach ◽  
System A

New Design for a Differentially Pumped Hydration Chamber for a Siemens IA

1971 ◽  
Vol 29 ◽  
pp. 44-45
Author(s):  
R. C. Moretz ◽  
G. G. Hausner ◽  
D. F. Parsons
Keyword(s):  
Electron Microscopy ◽  
Water Vapor ◽  
Electron Diffraction ◽  
Water Vapor Pressure ◽  
Biological Materials ◽  
Thin Membrane ◽  
Reliable System ◽  
System A ◽  
Water Films ◽  
Aperture Opening

Electron microscopy and diffraction of biological materials in the hydrated state requires the construction of a chamber in which the water vapor pressure can be maintained at saturation for a given specimen temperature, while minimally affecting the normal vacuum of the remainder of the microscope column. Initial studies with chambers closed by thin membrane windows showed that at the film thicknesses required for electron diffraction at 100 KV the window failure rate was too high to give a reliable system. A single stage, differentially pumped specimen hydration chamber was constructed, consisting of two apertures (70-100μ), which eliminated the necessity of thin membrane windows. This system was used to obtain electron diffraction and electron microscopy of water droplets and thin water films. However, a period of dehydration occurred during initial pumping of the microscope column. Although rehydration occurred within five minutes, biological materials were irreversibly damaged. Another limitation of this system was that the specimen grid was clamped between the apertures, thus limiting the yield of view to the aperture opening.

Influence of X-Ray Induced Fluorescence on Energy Dispersive X-Ray Analysis of Thin Foils

1977 ◽  
Vol 35 ◽  
pp. 328-329
Author(s):  
E. A. Kenik ◽  
J. Bentley
Keyword(s):  
Thin Foil ◽  
Electron Excitation ◽  
Simple Approach ◽  
Foil Thickness ◽  
X Rays ◽  
X Ray ◽  
Hole Spectrum ◽  
Illumination System ◽  
Thin Foils ◽  
Intensity Ratios

Cliff and Lorimer (1) have proposed a simple approach to thin foil x-ray analy sis based on the ratio of x-ray peak intensities. However, there are several experimental pitfalls which must be recognized in obtaining the desired x-ray intensities. Undesirable x-ray induced fluorescence of the specimen can result from various mechanisms and leads to x-ray intensities not characteristic of electron excitation and further results in incorrect intensity ratios.In measuring the x-ray intensity ratio for NiAl as a function of foil thickness, Zaluzec and Fraser (2) found the ratio was not constant for thicknesses where absorption could be neglected. They demonstrated that this effect originated from x-ray induced fluorescence by blocking the beam with lead foil. The primary x-rays arise in the illumination system and result in varying intensity ratios and a finite x-ray spectrum even when the specimen is not intercepting the electron beam, an ‘in-hole’ spectrum. We have developed a second technique for detecting x-ray induced fluorescence based on the magnitude of the ‘in-hole’ spectrum with different filament emission currents and condenser apertures.

High-resolution electron microscopy of Cu2O surfaces

1986 ◽  
Vol 44 ◽  
pp. 396-397
Author(s):  
V. Castano ◽  
W. Krakow
Keyword(s):  
High Resolution ◽  
Natural Extension ◽  
High Resolution Electron Microscopy ◽  
Point Of View ◽  
Initial Oxidation ◽  
System A ◽  
Resolution Electron ◽  
Surface Reconstructions ◽  
Atomic Surface ◽  
Au Thin Films

In non-UHV microscope environments atomic surface structure has been observed for flat-on for various orientations of Au thin films and edge-on for columns of atoms in small particles. The problem of oxidation of surfaces has only recently been reported from the point of view of high resolution microscopy revealing surface reconstructions for the Ag2O system. A natural extension of these initial oxidation studies is to explore other materials areas which are technologically more significant such as that of Cu2O, which will now be described.

Twin boundary structure of a Y-Ba-Cu-O superconductor

1989 ◽  
Vol 47 ◽  
pp. 168-169
Author(s):  
Yimei Zhu ◽  
Masaki Suenaga ◽  
R. L. Sabatini ◽  
Youwen Xu
Keyword(s):  
Twin Boundary ◽  
Fine Particles ◽  
Imaging Techniques ◽  
Fine Powder ◽  
Orthorhombic Phase ◽  
Boundary Structure ◽  
Crystallographic Axis ◽  
System A ◽  
High Resolution Structure ◽  
Electron Microscopes

The (110) twin structure of YBa2Cu3O7 superconductor oxide, which is formed to reduce the strain energy of the tetragonal to orthorhombic phase transformation by alternating the a-b crystallographic axis across the boundary, was extensively investigated. Up to now the structure of the twin boundary still remained unclear. In order to gain insight into the nature of the twin boundary in Y-Ba-Cu-O system, a study using electron diffraction techniques including optical and computed diffractograms, as well as high resolution structure imaging techniques with corresponding computer simulation and processing was initiated.Bulk samples of Y-Ba-Cu-O oxide were prepared as described elsewhere. TEM specimens were produced by crushing bulk samples into a fine powder, dispersing the powder in acetone, and suspending the fine particles on a holey carbon grid. The electron microscopy during this study was performed on both a JEOL 2000EX and 2000FX electron microscopes operated at 200 kV.

Speech Therapy Services in a Large School System: A Six-Year Overview

1976 ◽  
Vol 7 (4) ◽  
pp. 207-219 ◽  
Author(s):  
Constance P. DesRoches
Keyword(s):  
School System ◽  
Speech Therapy ◽  
Factors Affecting ◽  
Case Load ◽  
Number Of Children ◽  
School Population ◽  
System A ◽  
Therapy Services ◽  
And Shifts ◽  
Selection Factors

A statistical review provides analysis of four years of speech therapy services of a suburban school system which can be used for comparison with other school system programs. Included are data on the percentages of the school population enrolled in therapy, the categories of disabilities and the number of children in each category, the sex and grade-level distribution of those in therapy, and shifts in case-load selection. Factors affecting changes in case-load profiles are identified and discussed.

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