scholarly journals Physical observers, T-vacuum and Unruh like effect in the radiation dominated early universe

2020 ◽  
Vol 2020 (12) ◽  
Author(s):  
Sujoy K. Modak
Keyword(s):  
Excited State ◽  
Early Universe ◽  
Particle Creation ◽  
Vacuum State ◽  
Unruh Effect ◽  
Two Dimensional ◽  
Creation Process ◽  
Flat Spacetime ◽  
Set Up

Abstract We report the existence of an Unruh like effect, for physical observers (cosmo- logical and comoving observers) in the radiation dominated early universe, which is possible due to the discovery of a new vacuum state (referred here as the T−vacuum). Both the comoving and the cosmological observers, who are crucial in our understanding of cosmology, observe this T−vacuum as a particle excited state and are able to detect radiation due to particle creation. We draw a robust analogy with the Unruh effect, whereby — (i) the physical observers here are closely analogous to the accelerated (Rindler) observers in the flat spacetime, and (ii) the T−vacuum plays the role of the Minkowski vacuum state which contains particles when viewed from the physical observers frame. Our analogy is further supported by a proof of well-defined (hadamard) behavior of the T−vacuum in the entire spacetime. All our analysis of the particle creation process is done here within a two dimensional set up.

scholarly journals Gravitational Radiation as the Bremsstrahlung of Superheavy Particles in the Early Universe

Universe ◽  
2020 ◽  
Vol 6 (10) ◽  
pp. 188
Author(s):  
Andrey A. Grib ◽  
Yuri V. Pavlov
Keyword(s):  
Early Universe ◽  
Gravitational Radiation ◽  
Background Radiation ◽  
Particle Creation ◽  
Grand Unification ◽  
Expanding Universe ◽  
The Universe

The number of superheavy particles with the mass of the Grand Unification scale with trans-Planckian energy created at the epoch of superheavy particle creation from the vacuum by the gravitation of the expanding Universe is calculated. In later collisions of these particles, gravitational radiation is radiated playing the role of bremsstrahlung for gravity. The effective background radiation of the Universe is evaluated.

Dynamic adjustment of emission from both singlets and triplets: the role of excited state conformation relaxation and charge transfer in phenothiazine derivates

2021 ◽  
Author(s):  
Weidong Qiu ◽  
Xinyi Cai ◽  
Mengke Li ◽  
Liangying Wang ◽  
Yanmei He ◽  
...  
Keyword(s):  
Excited State ◽  
Charge Transfer ◽  
Intramolecular Charge Transfer ◽  
Dynamic Adjustment ◽  
Twisted Intramolecular Charge Transfer

Dynamic adjustment of emission behaviours by controlling the extent of twisted intramolecular charge transfer character in excited state.

A reconnaissance of tropical resources during Revolutionary years: the role of the Paris Museum d'Histoire Naturelle

1991 ◽  
Vol 18 (3) ◽  
pp. 333-362 ◽  
Author(s):  
MADELEINE LY-TIO-FANE
Keyword(s):  
South Africa ◽  
Natural History ◽  
Scientific Research ◽  
Extensive Literature ◽  
War Of Independence ◽  
Leading Role ◽  
Scientific Principles ◽  
Set Up ◽  
Joseph Ii

SUMMARY The recent extensive literature on exploration and the resulting scientific advances has failed to highlight the contribution of Austrian enterprise to the study of natural history. The leading role of Joseph II among the neutral powers which assumed the carrying trade of the belligerents during the American War of Independence, furthered the development of collections for the Schönbrunn Park and Gardens which had been set up on scientific principles by his parents. On the conclusion of peace, Joseph entrusted to Professor Maerter a world-encompassing mission in the course of which the Chief Gardener Franz Boos and his assistant Georg Scholl travelled to South Africa to collect plants and animals. Boos pursued the mission to Isle de France and Bourbon (Mauritius and Reunion), conveyed by the then unknown Nicolas Baudin. He worked at the Jardin du Roi, Pamplemousses, with Nicolas Cere, or at Palma with Joseph Francois Charpentier de Cossigny. The linkage of Austrian and French horticultural expertise created a situation fraught with opportunities which were to lead Baudin to the forefront of exploration and scientific research as the century closed in the upheaval of the Revolutionary Wars.

Success Drivers of Urban Haats Selling Craft Products

2020 ◽  
pp. 097300522096468
Author(s):  
Rajesh Gupta ◽  
Piyush Kumar Sinha ◽  
Akash Sahu ◽  
Vandana Sood
Keyword(s):  
Mixed Method ◽  
Rural Economy ◽  
Mediating Role ◽  
Role Based ◽  
Craft Industry ◽  
Set Up ◽  
Market Separations ◽  
Method Approach

Craft industry is as much the mainstay of the rural economy after agriculture. It provides occupation to a large section of population. However, it is characterised by fragmented individual artisans on one side and dispersed customers on the other. It also suffers from market separations. Urban haats were set up with the objective to present artisans and buyer on one platform and reduce these separations. In this study urban haats have been conceptualised as marketplaces that bring artisans and customers at one place to optimise their respective values. They also serve as a tool for disintermediation and a social distribution initiative and represent a retailing initiative in the inclusive entrepreneurship domain. This study focusses on identifying drivers of success of urban haats. Using a mixed method approach, data was collected from Haat officials and NGO members through personal interviews. The data from artisans and customers was collected through a survey using a structured response format. The study was conducted at 18 haats in 10 states. The study highlights the factors that drive satisfaction of artisans and customers and the role of administrators in making the marketplace a success. Customer consider diversity of the products, quality of the products, behaviour of the salesperson, price parity with other markets, buying experience, parking space and aesthetics of the stalls as major influencing factors for the recommendation of the haats to other customers. Most important attributes of the haats in driving artisan satisfaction were stall allotment system, haat location, advertisements, product promotion and monitoring. It is also found that while the infrastructure is necessary, it is not sufficient in enhancing the performance and sustainability of haats. Administration of these haats plays a defining mediating role. Based on these findings, an approach is proposed for success of urban haats.

Tissue Ki67 proliferative index expression and pathological changes in hemodialysis arteriovenous fistulae: Preliminary single-center results

2021 ◽  
pp. 112972982110154
Author(s):  
Raffaella Mauro ◽  
Cristina Rocchi ◽  
Francesco Vasuri ◽  
Alessia Pini ◽  
Anna Laura Croci Chiocchini ◽  
...  
Keyword(s):  
Morphological Changes ◽  
Hot Spot ◽  
Wall Thickening ◽  
Proliferating Cells ◽  
Ki 67 ◽  
Group A ◽  
The Mean ◽  
Set Up ◽  
Group B

Background: Arteriovenous fistula (AVF) for hemodialysis integrates outward remodeling with vessel wall thickening in response to drastic hemodynamic changes. Aim of this study is to determine the role of Ki67, a well-established proliferative marker, related to AVF, and its relationship with time-dependent histological morphologic changes. Materials and methods: All patients were enrolled in 1 year and stratified in two groups: (A) pre-dialysis patients submitted to first AVF and (B) patients submitted to revision of AVF. Morphological changes: neo-angiogenesis (NAG), myointimal thickening (MIT), inflammatory infiltrate (IT), and aneurysmatic fistula degeneration (AD). The time of AVF creation was recorded. A biopsy of native vein in Group A and of arterialized vein in Group B was submitted to histological and immunohistochemical (IHC) analysis. IHC for Ki67 was automatically performed in all specimens. Ki67 immunoreactivity was assessed as the mean number of positive cells on several high-power fields, counted in the hot spots. Results: A total of 138 patients were enrolled, 69 (50.0%) Group A and 69 (50.0%) Group B. No NAG or MIT were found in Group A. Seven (10.1%) Group A veins showed a mild MIT. Analyzing the Group B, a moderate-to-severe MIT was present in 35 (50.7%), IT in 19 (27.5%), NAG in 37 (53.6%); AD was present in 10 (14.5%). All AVF of Group B with the exception of one (1.4%) showed a positivity for Ki67, with a mean of 12.31 ± 13.79 positive cells/hot spot (range 0–65). Ki67-immunoreactive cells had a subendothelial localization in 23 (33.3%) cases, a myointimal localization in SMC in 35 (50.7%) cases. The number of positive cells was significantly correlated with subendothelial localization of Ki67 ( p = 0.001) and with NA ( p = 0.001). Conclusions: Native veins do not contain cycling cells. In contrast, vascular cell proliferation starts immediately after AVF creation and persists independently of the time the fistula is set up. The amount of proliferating cells is significantly associated with MIT and subendothelial localization of Ki67-immunoreactive cells, thus suggesting a role of Ki-67 index in predicting AVF failure.

Majolica in the Early Colonial Andes: The Role of Panamanian Wares

2001 ◽  
Vol 12 (1) ◽  
pp. 45-58 ◽  
Author(s):  
Ross W. Jamieson
Keyword(s):  
Spanish Colonial ◽  
Important Indicator ◽  
The Andes ◽  
Early Colonial ◽  
The Pacific ◽  
Elite Status ◽  
Set Up ◽  
The City ◽  
Made In

As one of the most common artifact categories found on Spanish colonial sites, the wheel-made, tin-glazed pottery known as majolica is an important chronological and social indicator for archaeologists. Initially imported from Europe, several manufacturing centers for majolica were set up in the New World by the late sixteenth century. The study of colonial majolica in the Viceroyalty of Peru, which encompassed much of South America, has received less attention than ceramic production and trade in the colonial Caribbean and Mesoamerica. Prior to 1650 the Viceroyalty of Peru was supplied with majolica largely produced in the city of Panama Vieja, on the Pacific. Panama Vieja majolica has been recovered from throughout the Andes, as far south as Argentina. Majolica made in Panama Vieja provides an important chronological indicator of early colonial archaeological contexts in the region. The reproduction of Iberian-style majolica for use on elite tables was symbolically important to the imposition of Spanish rule, and thus Panamanian majolicas also provide an important indicator of elite status on Andean colonial sites.

scholarly journals Revealing the role of excited state proton transfer (ESPT) in excited state hydrogen transfer (ESHT): systematic study in phenol–(NH3)n clusters

2021 ◽  
Author(s):  
Christophe Jouvet ◽  
Mitsuhiko Miyazaki ◽  
Masaaki Fujii
Keyword(s):  
Excited State ◽  
Proton Transfer ◽  
Systematic Study ◽  
General Model ◽  
Hydrogen Transfer ◽  
Excited State Proton Transfer

A general model of excited state hydrogen transfer (ESHT) which unifies ESHT and the excited state proton transfer (ESPT) is presented from experimental and theoretical works on phenol–(NH3)n. The hidden role of ESPT is revealed.

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