Dynamical theory of neutron diffraction

1978 ◽  
Vol 56 (10) ◽  
pp. 1261-1288 ◽  
Author(s):  
V. F. Sears
Keyword(s):  
Neutron Diffraction ◽  
Theoretical Basis ◽  
Dynamical Theory ◽  
Experimental Results ◽  
Neutron Interferometry ◽  
New Techniques ◽  
The Past ◽  
Neutron Optics ◽  
Coherent Wave ◽  
Special Cases

We present a review of the dynamical theory of neutron diffraction by macroscopic bodies which provides the theoretical basis for the study of neutron optics. We consider both the theory of dispersion, in which it is shown that the coherent wave in the medium satisfies a macroscopic one-body Schrödinger equation, and the theory of reflection, refraction, and diffraction in which the above equation is solved for a number of special cases of interest. The theory is illustrated with the help of experimental results obtained over the past 10 years by a number of new techniques such as neutron gravity refractometry, Pendellösung interference, and neutron interferometry.

Advanced Techniques for Measuring Structural Mobilities

1988 ◽  
Vol 110 (3) ◽  
pp. 345-349 ◽  
Author(s):  
J. A. Fabunmi ◽  
F. A. Tasker
Keyword(s):  
Frequency Response ◽  
General Equation ◽  
Theoretical Basis ◽  
Weighting Function ◽  
Experimental Results ◽  
Expected Improvement ◽  
Response Functions ◽  
Proper Selection ◽  
Special Cases ◽  
Selection Of

A unified formulation of the equations for estimating structural frequency response functions is presented. The more popular approaches are shown to be special cases of a general equation which involves a weighting function, the proper selection of which can yield substantial improvements in the accuracy and efficiency of the measurement process. The theoretical basis for selecting the weighting function is also presented, along with experimental results which confirm the expected improvement in accuracy of the advanced formulations over existing methods.

Stellar Evolution

1962 ◽  
Vol 11 (02) ◽  
pp. 137-143
Author(s):  
M. Schwarzschild
Keyword(s):  
Solar System ◽  
Stellar Evolution ◽  
Space Craft ◽  
New Techniques ◽  
Substantial Body ◽  
Individual Stars ◽  
The Past ◽  
Evolution Of Galaxies ◽  
History Of ◽  
Fast Flow

It is perhaps one of the most important characteristics of the past decade in astronomy that the evolution of some major classes of astronomical objects has become accessible to detailed research. The theory of the evolution of individual stars has developed into a substantial body of quantitative investigations. The evolution of galaxies, particularly of our own, has clearly become a subject for serious research. Even the history of the solar system, this close-by intriguing puzzle, may soon make the transition from being a subject of speculation to being a subject of detailed study in view of the fast flow of new data obtained with new techniques, including space-craft.

Compiler-Aided Run-Time Performance Speed-Up in Super-Scalar Processor

10.28945/3391 ◽  
2009 ◽  
Author(s):  
Moshe Pelleh
Keyword(s):  
Embedded Systems ◽  
Embedded System ◽  
General Purpose ◽  
Experimental Results ◽  
Medium Size ◽  
Organic System ◽  
Software Application ◽  
Organic Systems ◽  
Special Cases ◽  
Run Time

In our world, where most systems become embedded systems, the approach of designing embedded systems is still frequently similar to the approach of designing organic systems (or not embedded systems). An organic system, like a personal computer or a work station, must be able to run any task submitted to it at any time (with certain constrains depending on the machine). Consequently, it must have a sophisticated general purpose Operating System (OS) to schedule, dispatch, maintain and monitor the tasks and assist them in special cases (particularly communication and synchronization between them and with external devices). These OSs require an overhead on the memory, on the cache and on the run time. Moreover, generally they are task oriented rather than machine oriented; therefore the processor's throughput is penalized. On the other hand, an embedded system, like an Anti-lock Braking System (ABS), executes always the same software application. Frequently it is a small or medium size system, or made up of several such systems. Many small or medium size embedded systems, with limited number of tasks, can be scheduled by our proposed hardware architecture, based on the Motorola 500MHz MPC7410 processor, enhancing its throughput and avoiding the software OS overhead, complexity, maintenance and price. Encouraged by our experimental results, we shall develop a compiler to assist our method. In the meantime we will present here our proposal and the experimental results.

scholarly journals Sixty Years with the Chrysobalanaceae

2020 ◽  
Author(s):  
Ghillean T. Prance
Keyword(s):  
Economic Botany ◽  
Field Studies ◽  
Molecular Evidence ◽  
New Techniques ◽  
Conservation Ecology ◽  
The Past ◽  
New Findings ◽  
The Family ◽  
Molecular Studies ◽  
Economic Use

AbstractA review is given of the studies of Ghillean Prance and associates on the Chrysobalanaceae over the past sixty years. This has focussed on defining the generic boundaries in the family and on monographic work with a worldwide approach to this pantropical family. The importance of field studies for work on monographs and Floras is emphasized. Monographs are still the basis for much work on conservation, ecology and economic botany and are needed as a foundation for molecular studies. The importance of being open to experimenting with new techniques and as a result being willing to change the taxonomy in accordance with new findings is demonstrated and emphasized. The twelve genera of the Chrysobalanaceae at the beginning of this career-long study have now increased to twenty-eight in order to present a much better monophyletic and evolutionary arrangement based on recent molecular evidence. In particular it was necessary to divide and rearrange the originally large genera Parinari and Licania into a number of smaller segregate genera. All known species were included in a worldwide monograph published in 2003. A brief review of the economic use for the family is given.

Line Contact Deformation: A Cylinder Between Two Flat Plates

1981 ◽  
Vol 103 (1) ◽  
pp. 21-25 ◽  
Author(s):  
M. R. Hoeprich ◽  
H. Zantopulos
Keyword(s):  
Plane Strain ◽  
General Equation ◽  
Roller Bearing ◽  
Experimental Results ◽  
Line Contact ◽  
Contact Deformation ◽  
Flat Plates ◽  
Special Cases ◽  
Analytical Work

Various line contact deformation equations used in roller bearing technology are analyzed. Many of these deformation equations, primarily involving plane strain, are shown to be special cases of a general equation derived in this paper. Experimental results are also presented to support the results of the analytical work.

scholarly journals Escherichia coli as a genetic tool

1985 ◽  
Vol 95 (3) ◽  
pp. 611-618
Author(s):  
Naomi Datta
Keyword(s):  
Escherichia Coli ◽  
Academic Research ◽  
Genetically Engineered ◽  
Cloning And Expression ◽  
Biological Research ◽  
New Techniques ◽  
E Coli ◽  
Genetic Tool ◽  
The Past ◽  
Made In

SUMMARYThe study of Escherichia coli and its plasmids and bacteriophages has provided a vast body of genetical information, much of it relevant to the whole of biology. This was true even before the development of the new techniques, for cloning and analysing DNA, that have revolutionized biological research during the past decade. Thousands of millions of dollars are now invested in industrial uses of these techniques, which all depend on discoveries made in the course of academic research on E. coli. Much of the background of knowledge necessary for the cloning and expression of genetically engineered information, as well as the techniques themselves, came from work with this organism.

scholarly journals The Evolution of Mathematics in Ancient China: From the newly discovered 數 Shu and 算數書 Suan Shu Shu Bamboo Texts to the Nine Chapters on the Art of Mathematics

2020 ◽  
Vol 19 (37) ◽  
pp. 25-78
Author(s):  
Joseph W. Dauben
Keyword(s):  
History Of Mathematics ◽  
Plenary Lecture ◽  
Ancient China ◽  
New Techniques ◽  
Tsinghua University ◽  
Warring States ◽  
The Past ◽  
Peking University ◽  
History Of ◽  
Mathematical Texts

The history of ancient Chinese mathematics and its applications has been greatly stimulated in the past few decades by remarkable archaeological discoveries of texts from the pre-Qin and later periods that make it possible to study in detail mathematical material from the time at which it was written. By examining the recent Warring States, Qin and Han bamboo mathematical texts currently being conserved and studied at Tsinghua University and Peking University in Beijing, the Yuelu Academy in Changsha, and the Hubei Museum in Wuhan, it is possible to shed new light on the history of early mathematical thought and its applications in ancient China. Also discussed here are developments of new techniques and justifications given for the problems that were a significant part of the growing mathematical corpus, and which eventually culminated in the comprehensive Nine Chapters on the Art of Mathematics. What follows is a revised text of an invited plenary lecture given during the 10th National Seminar on the History of Mathematics at UNICAMP in Campinas, SP, Brazil, on March 27, 2013.

Thermal Science of Weld Bead Defects: A Review

2010 ◽  
Vol 133 (3) ◽  
Author(s):  
P. S. Wei
Keyword(s):  
Stress Concentration ◽  
Experimental Results ◽  
Materials Processing ◽  
Scale Analysis ◽  
Fluid Physics ◽  
The Past ◽  
Good Comparison ◽  
Surface Patterns ◽  
Pattern Formations ◽  
Working Parameters

Mechanisms for the formation of bead defects, such as humping, gouging, rippling, and other unexpected surface patterns, encountered in welding or drilling are interpreted and reviewed from thermal-fluid science viewpoint. These defects usually accompanying with porosity, undercut, segregation, stress concentration, etc., seriously reduce the properties and strength of the joint or solidification. Even though different mechanisms for formation of the defects have been extensively proposed in the past, more systematical understanding of pattern formations from thermal, fluid, physics, electromagnetic, pattern selections, and metallurgy sciences is still limited. The effects of working parameters and properties on humping and rippling, for example, can be systematically and quantitatively interpreted from scale analysis presented in this work. Good comparison with experimental results reveals mechanisms of different surface patterns. The mechanistic findings for bead defects are also useful for other manufacturing and materials processing.

Adenocarcinoma in Barrett Mucosa Treated by Endoscopic Mucosal Resection

2009 ◽  
Vol 133 (11) ◽  
pp. 1793-1797 ◽  
Author(s):  
Henry D. Appelman
Keyword(s):  
Endoscopic Mucosal Resection ◽  
Genetic Test ◽  
New Technology ◽  
Muscularis Mucosae ◽  
New Techniques ◽  
The Past ◽  
Mucosal Resection ◽  
Medical Centers ◽  
Standard Procedures ◽  
Microscopic Interpretation

Abstract Adenocarcinoma and dysplasias are recognized complications of Barrett mucosa. In the past, the treatment for this carcinoma was esophagectomy. However, new techniques, including endoscopic mucosal resection, sometimes replace esophagectomy and are becoming standard procedures in clinical practice, not just in major medical centers. Pathologists must learn to handle these specimens, which have extensive artifacts. Also, Barrett mucosa has duplicated stromal layers beneath the mucosa that include a new lamina propria and a new muscularis mucosae. We must be aware of these peculiarities because of staging implications. Regardless of new technology, the diagnostic approach to dysplasia depends on the light microscopic interpretation, which is not as reliable or consistent as one would wish. Hopefully, better diagnostic criteria will arise, and perhaps a new histologic stain or a molecular or genetic test will emerge that complements “our eyeballs.”

Digital Prepress

2011 ◽  
pp. 24-39
Author(s):  
Mark Snyder
Keyword(s):  
Historical Perspective ◽  
Print Media ◽  
Digital Technologies ◽  
Printing Industry ◽  
New Techniques ◽  
Digital Revolution ◽  
The Past ◽  
Problems And Solutions ◽  
Common Problems ◽  
Work Done

This chapter identifies changes that the printing industry has undergone during the past 25 years as a result of the digital revolution. It also provides a brief historical perspective of the printing industry and how it has evolved. It is undeniable that the computer has had an impact on the development of print media and today it is rare to find any prepress work done without the use of some digital technology. The workflow of a traditional printed piece is described from start to finish and is compared to a more modern digital workflow to familiarize readers with the processes and contrast the old with the new techniques. This chapter will identify common problems that occur in the preparation of print media using digital technologies. In particular, it will explore a variety of problems and solutions related to the use of digital prepress as well as identifying new innovations intended to improve prepress operations in the future.

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