Conformational analysis by infrared linear dichroism of solutes in stretched polyethylene: The twist angle in biphenyl and 4,4'-dibromobiphenyl

1988 ◽  
Vol 53 (10) ◽  
pp. 2366-2376 ◽  
Author(s):  
Parvathi S. Murthy ◽  
Josef Michl
Keyword(s):  
Conformational Analysis ◽  
Twist Angle ◽  
Spatial Relationship ◽  
Linear Dichroism ◽  
Molecular Shape ◽  
Isotopic Substitution ◽  
Weakly Coupled ◽  
Orientation Mechanism ◽  
Relationship Of

A method is proposed for using the IR linear dichroism of molecules embedded in stretched polyethylene and containing two weakly coupled symmetry-related subunits for the determination of the spatial relationship of the subunits. The procedure requires an IR LD measurement on the parent and on an isotopomer in which the equivalence of the subunits has been removed by isotopic substitution, without affecting the molecular shape or the orientation factors. The method has been tested on biphenyl, found to be planar, and 4,4'-dibromobiphenyl, found to be nearly orthogonally twisted in stretched polyethylene. Possible implications for the orientation mechanism are discussed briefly.

Ultrastructural evidence for mast cell-macrophage interrelationships in the dura mater of the rat: Infrequent mast cell-nerve associations

1990 ◽  
Vol 48 (3) ◽  
pp. 352-353
Author(s):  
Ruth V.W. Dimlich
Keyword(s):  
Mast Cell ◽  
Mast Cells ◽  
Dura Mater ◽  
Spatial Relationship ◽  
Potassium Phosphate ◽  
Plasma Extravasation ◽  
Close Spatial Relationship ◽  
Male Wistar Rats ◽  
Headache Pain ◽  
Relationship Of

Mast cells in the dura mater of the rat may play a role in cerebral pathologies including neurogenic inflammation (vasodilation; plasma extravasation) and headache pain . As has been suggested for other tissues, dural mast cells may exhibit a close spatial relationship to nerves. There has been no detailed ultrastructural description of mast cells in this tissue; therefore, the goals of this study were to provide this analysis and to determine the spatial relationship of mast cells to nerves and other components of the dura mater in the rat.Four adult anesthetized male Wistar rats (290-400 g) were fixed by perfusion through the heart with 2% glutaraldehyde and 2.8% paraformaldehyde in a potassium phosphate buffer (pH 7.4) for 30 min. The head of each rat was removed and stored in fixative for a minimum of 24 h at which time the dural coverings were removed and dissected into samples that included the middle meningeal vasculature. Samples were routinely processed and flat embedded in LX 112. Thick (1 um) sections from a minimum of 3 blocks per rat were stained with toluidine blue (0.5% aqueous).

STEM and ELS Observation of Early Oxide Formation on the Surface of Cr Thin Films

1980 ◽  
Vol 38 ◽  
pp. 412-413
Author(s):  
Fumio Watari ◽  
J. M. Cowley
Keyword(s):  
Thin Films ◽  
Optical System ◽  
Room Temperature ◽  
Oxide Formation ◽  
Initial Nucleation ◽  
Diffraction Patterns ◽  
Relationship Of ◽  
Multiple Twinning ◽  
Moderately High Temperature

STEM coupled with the optical system was used for the investigation of the early oxidation on the surface of Cr. Cr thin films (30 – 1000Å) were prepared by evaporation onto the polished or air-cleaved NaCl substrates at room temperature and 45°C in a vacuum of 10−6 Torr with an evaporation speed 0.3Å/sec. Rather thick specimens (200 – 1000Å) with various preferred orientations were used for the investigation of the oxidation at moderately high temperature (600 − 1100°C). Selected area diffraction patterns in these specimens are usually very much complicated by the existence of the different kinds of oxides and their multiple twinning. The determination of the epitaxial orientation relationship of the oxides formed on the Cr surface was made possible by intensive use of the optical system and microdiffraction techniques. Prior to the formation of the known rhombohedral Cr2O3, a thin spinel oxide, probably analogous to γ -Al203 or γ -Fe203, was formed. Fig. 1a shows the distinct epitaxial growth of the spinel (001) as well as the rhombohedral (125) on the well-oriented Cr(001) surface. In the case of the Cr specimen with the (001) preferred orientation (Fig. 1b), the rings explainable by spinel structure appeared as well as the well defined epitaxial spots of the spinel (001). The microdif fraction from 20A areas (Fig. 2a) clearly shows the same pattern as Fig. Ia with the weaker oxide spots among the more intense Cr spots, indicating that the thickness of the oxide is much less than that of Cr. The rhombohedral Cr2O3 was nucleated preferably at the Cr(011) sites provided by the polycrystalline nature of the present specimens with the relation Cr2O3 (001)//Cr(011), and by further oxidation it grew into full coverage of the rest of the Cr surface with the orientation determined by the initial nucleation.

Calculating the aerodynamics of vertical axis wind turbines

2012 ◽  
Vol 34 (3) ◽  
pp. 169-184 ◽  
Author(s):  
Hoang Thi Bich Ngoc
Keyword(s):  
Wind Turbine ◽  
Incidence Angle ◽  
Vertical Axis ◽  
Rotor Blades ◽  
Vertical Axis Wind Turbine ◽  
Horizontal Axis Wind Turbine ◽  
Velocity Triangle ◽  
Relationship Of ◽  
The Relationship

Vertical axis wind turbine technology has been applied last years, very long after horizontal axis wind turbine technology. Aerodynamic problems of vertical axis wind machines are discussible. An important problem is the determination of the incidence law in the interaction between wind and rotor blades. The focus of the work is to establish equations of the incidence depending on the blade azimuth, and to solve them. From these results, aerodynamic torques and power can be calculated. The incidence angle is a parameter of velocity triangle, and both the factors depend not only on the blade azimuth but also on the ratio of rotational speed and horizontal speed. The built computational program allows theoretically selecting the relationship of geometric parameters of wind turbine in accordance with requirements on power, wind speed and installation conditions.

Tire Treadwear — A Comprehensive Evaluation of the Factors: Generic Type, Aspect Ratio, Tread Pattern, and Tread Composition Part I: Introduction and Details on the Organization of the Program

1986 ◽  
Vol 14 (4) ◽  
pp. 201-218 ◽  
Author(s):  
A. G. Veith
Keyword(s):  
Aspect Ratio ◽  
Comprehensive Evaluation ◽  
Test Method ◽  
Interactive Effects ◽  
Data Analyses ◽  
Main Effect ◽  
Systematic Determination ◽  
Relationship Of ◽  
The Relationship

Abstract This four-part series of papers addresses the problem of systematic determination of the influence of several tire factors on tire treadwear. Both the main effect of each factor and some of their interactive effects are included. The program was also structured to evaluate the influence of some external-to-tire conditions on the relationship of tire factors to treadwear. Part I describes the experimental design used to evaluate the effects on treadwear of generic tire type, aspect ratio, tread pattern (groove or void level), type of pattern (straight rib or block), and tread compound. Construction procedures and precautions used to obtain a valid and functional test method are included. Two guiding principles to be used in the data analyses of Parts II and III are discussed. These are the fractional groove and void concept, to characterize tread pattern geometry, and a demonstration of the equivalence of wear rate for identical compounds on whole tread or multi-section tread tires.

Asymmetric Total Synthesis and Determination of the Absolute Configuration of (+)-Srilankenyne via Sequence-Sensitive Halogenations Guided by Conformational Analysis

2021 ◽  
Vol 23 (4) ◽  
pp. 1321-1326
Author(s):  
Hongjun Jang ◽  
Soo Yeon Kwak ◽  
Dongjoo Lee ◽  
Juan V. Alegre-Requena ◽  
Hyoungsu Kim ◽  
...  
Keyword(s):  
Total Synthesis ◽  
Conformational Analysis ◽  
Absolute Configuration ◽  
Asymmetric Total Synthesis ◽  
The Absolute

scholarly journals Geo-Spatial Analysis of Population Density and Annual Income to Identify Large-Scale Socio-Demographic Disparities

2021 ◽  
Vol 10 (7) ◽  
pp. 432
Author(s):  
Nicolai Moos ◽  
Carsten Juergens ◽  
Andreas P. Redecker
Keyword(s):  
Population Density ◽  
Large Scale ◽  
Methodological Approach ◽  
Spatial Relationship ◽  
Postal Code ◽  
Annual Income ◽  
Choropleth Maps ◽  
Clustering Approach ◽  
Relationship Of ◽  
Insight Into

This paper describes a methodological approach that is able to analyse socio-demographic and -economic data in large-scale spatial detail. Based on the two variables, population density and annual income, one investigates the spatial relationship of these variables to identify locations of imbalance or disparities assisted by bivariate choropleth maps. The aim is to gain a deeper insight into spatial components of socioeconomic nexuses, such as the relationships between the two variables, especially for high-resolution spatial units. The used methodology is able to assist political decision-making, target group advertising in the field of geo-marketing and for the site searches of new shop locations, as well as further socioeconomic research and urban planning. The developed methodology was tested in a national case study in Germany and is easily transferrable to other countries with comparable datasets. The analysis was carried out utilising data about population density and average annual income linked to spatially referenced polygons of postal codes. These were disaggregated initially via a readapted three-class dasymetric mapping approach and allocated to large-scale city block polygons. Univariate and bivariate choropleth maps generated from the resulting datasets were then used to identify and compare spatial economic disparities for a study area in North Rhine-Westphalia (NRW), Germany. Subsequently, based on these variables, a multivariate clustering approach was conducted for a demonstration area in Dortmund. In the result, it was obvious that the spatially disaggregated data allow more detailed insight into spatial patterns of socioeconomic attributes than the coarser data related to postal code polygons.

scholarly journals Multimessenger Probes for New Physics in Light of A. Sakharov’s Legacy in Cosmoparticle Physics

Universe ◽  
2021 ◽  
Vol 7 (7) ◽  
pp. 222
Author(s):  
Maxim Khlopov
Keyword(s):  
Standard Model ◽  
Particle Physics ◽  
New Physics ◽  
Physical Models ◽  
Beyond The Standard Model ◽  
Fundamental Relationship ◽  
Relationship Of ◽  
The Universe ◽  
Selection Of

A.D. Sakharov’s legacy in now standard model of the Universe is not reduced to baryosynthesis but extends to the foundation of cosmoparticle physics, which studies the fundamental relationship of cosmology and particle physics. Development of cosmoparticle physics involves cross-disciplinary physical, astrophysical and cosmological studies of physics Beyond the Standard model (BSM) of elementary particles. To probe physical models for inflation, baryosynthesis and dark matter cosmoparticle physics pays special attention to model dependent messengers of the corresponding models, making their tests possible. Positive evidence for such exotic phenomena as nuclear interacting dark atoms, primordial black holes or antimatter globular cluster in our galaxy would provide the selection of viable BSM models determination of their parameters.

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