New Theories of Nuclear Reactions

2018 ◽  
Author(s):  
Roger H. Stuewer
Keyword(s):  
Compound Nucleus ◽  
Nuclear Reactions ◽  
High Energy ◽  
Ernest Rutherford ◽  
Eugene Wigner ◽  
The World ◽  
Experimental Physicist ◽  
Theoretical Physicist ◽  
Michael Faraday ◽  
Gregory Breit

Bohr, inspired by Fermi’s discovery of slow neutrons, conceived his theory of the compound nucleus by the end of 1935. He went on to speculate that if the energy of a neutron incident on a nucleus were increased to the fantastically high energy of 1000 million electron volts, the compound nucleus would explode. Using small wooden models Otto Robert Frisch had constructed, Bohr lectured widely on his theory on a trip around the world in the first half of 1937. By then, Russian-born theoretical physicist Gregory Breit and Hungarian-born theoretical physicist Eugene Wigner in Princeton had conceived their fundamentally equivalent theory of neutron+nucleus resonances. Together, their theory and Bohr’s transformed the theory of nuclear reactions. Orso Mario Corbino, Fermi’s mentor, friend, and protector, died on January 23, 1937, at age sixty. Ernest Rutherford, the greatest experimental physicist since Michael Faraday, died on October 19, 1937, at age sixty-six.

scholarly journals Time Compound Nucleus for High Energy Nuclear Reactions

1983 ◽  
Vol 69 (1) ◽  
pp. 158-170 ◽  
Author(s):  
K. Izumo ◽  
H. Araseki
Keyword(s):  
Compound Nucleus ◽  
Nuclear Reactions ◽  
High Energy

Fundamentality

2017 ◽  
Author(s):  
Richard Healey
Keyword(s):  
Quantum Theory ◽  
High Energy Physics ◽  
Physical Property ◽  
Natural World ◽  
High Energy ◽  
Quantum Field Theories ◽  
Fundamental Physics ◽  
The World ◽  
Energy Physics

The metaphor that fundamental physics is concerned to say what the natural world is like at the deepest level may be cashed out in terms of entities, properties, or laws. The role of quantum field theories in the Standard Model of high-energy physics suggests that fundamental entities, properties, and laws are to be sought in these theories. But the contextual ontology proposed in Chapter 12 would support no unified compositional structure for the world; a quantum state assignment specifies no physical property distribution sufficient even to determine all physical facts; and quantum theory posits no fundamental laws of time evolution, whether deterministic or stochastic. Quantum theory has made a revolutionary contribution to fundamental physics because its principles have permitted tremendous unification of science through the successful application of models constructed in conformity to them: but these models do not say what the world is like at the deepest level.

Status of Cerium Fluoride Performances

1994 ◽  
Vol 348 ◽  
Author(s):  
E. Auffray ◽  
I. Dafinei ◽  
P. Lecoq ◽  
M. Schneegans
Keyword(s):  
Decay Time ◽  
High Energy Physics ◽  
Light Yield ◽  
High Energy ◽  
Radiation Hardness ◽  
Cerium Fluoride ◽  
The World ◽  
Electromagnetic Calorimeters ◽  
Physics Experiments ◽  
Energy Physics

ABSTRACTCerium fluoride offers a reasonable compromise between parameters like the density, the light yield, the scintillation characteristics (particularly the decay time) and the radiation hardness, and is considered today as the best candidate for large electromagnetic calorimeters in future High Energy Physics experiments. Details on the performances of large crystals produced by different manufacturers all over the world and measured by the Crystal Clear collaboration will be shown and the usefulness of a good collaboration between the industry and the users will be highlighted by some examples on the light yield and radiation hardness improvement.

Interrelation between Qai’lullah, Blue Light Exposure and Neurocognitive Performances: A Short Review

2021 ◽  
Vol 02 (02) ◽  
Author(s):  
Nur Farhana Fadzil ◽  
◽  
Siti Amira Othman ◽  
Keyword(s):  
Job Performance ◽  
Blue Light ◽  
Memory Consolidation ◽  
Light Exposure ◽  
Short Review ◽  
High Energy ◽  
Neurocognitive Performance ◽  
Night Sleep ◽  
Visual Contrast ◽  
The World

Qai’lullah or napping is a phenomenon that is widely practiced in the world. Islam advocates mid-day napping as it is primarily practiced by the Prophet Muhammad (pbuh). Scientists and scholars also acknowledge the benefits beyond this practice after various research and studies done. Hence, this article emphasizes topic of sleep in Islamic insight, their stages of sleeps according to Quran and the practiced of Qai’lullah or mid-day napping. The high-energy blue light exposure from the natural source, Sun and also digital screens reported reduce visual contrast and affect the sharpness and clarity by creating glares lead to mental and physical fatigue. Thus, a short nap in the mid-afternoon helps to boost memory, lift our mood, and improve job performance. The effect associated with qai’lullah are also being reviewed including improved the neurocognitive performance, alertness, recover the loss night sleep and enhanced the quality and increased memory consolidation in people.

scholarly journals SELECTED TOPICS IN HIGH ENERGY SEMI-EXCLUSIVE ELECTRO-NUCLEAR REACTIONS

2001 ◽  
Vol 10 (06) ◽  
pp. 405-457 ◽  
Author(s):  
MISAK M. SARGSIAN
Keyword(s):  
Present Status ◽  
Short Range ◽  
Nuclear Reactions ◽  
Eikonal Approximation ◽  
High Energy ◽  
Glauber Theory ◽  
Nucleon Recoil ◽  
High Energy Scattering ◽  
Nuclear Targets ◽  
Short Range Correlations

We review the present status of the theory of high energy reactions with semi-exclusive nucleon electro-production from nuclear targets. We demonstrate how the increase of transferred energies in these reactions opens a completely new window for study of the microscopic nuclear structure at small distances. The simplifications in theoretical descriptions associated with the increase in the energies are discussed. The theoretical framework for calculation of high energy nuclear reactions based on the effective Feynman diagram rules is described in detail. The result of this approach is the generalized eikonal approximation (GEA), which is reduced to the Glauber approximation when nucleon recoil is neglected. The method of GEA is demonstrated in the calculation of high energy electro-disintegration of the deuteron and A=3 targets. Subsequently, we generalize the obtained formulae for A>3 nuclei. The relation of GEA to the Glauber theory is analyzed. Then, based on the GEA framework we discuss some of the phenomena which can be studied in exclusive reactions: nuclear transparency and short-range correlations in nuclei. We illustrate how light-cone dynamics of high-energy scattering emerge naturally in high energy electro-nuclear reactions.

scholarly journals Study of the 232Th(n,f) Cross section at NCSR ‘Demokritos’ using Micromegas Detectors

2020 ◽  
Vol 27 ◽  
pp. 106
Author(s):  
Sotirios Chasapoglou ◽  
A. Tsantiri ◽  
A. Kalamara ◽  
M. Kokkoris ◽  
V. Michalopoulou ◽  
...  
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Nuclear Reactions ◽  
Detection Efficiency ◽  
High Energy ◽  
Tandem Accelerator ◽  
Line Detector ◽  
Accelerator Driven Systems ◽  
The Masses

The accurate knowledge of neutron-induced fission cross sections in actinides, is of great importance when it comes to the design of fast nuclear reactors, as well as accelerator driven systems. Specifically for the 232Th(n,f) case, the existing experimental datasets are quite discrepant in both the low and high energy MeV regions, thus leading to poor evaluations, a fact that in turn implies the need for more accurate measurements.In the present work, the total cross section of the 232Th(n,f) reaction has been measured relative to the 235U(n,f) and 238U(n,f) ones, at incident energies of 7.2, 8.4, 9.9 MeV and 14.8, 16.5, 17.8 MeV utilizing the 2H(d,n) and 3H(d,n) reactions respectively, which generally yield quasi-monoenergetic neutron beams. The experiments were performed at the 5.5 MV Tandem accelerator laboratory of N.C.S.R. “Demokritos”, using a Micromegas detector assembly and an ultra thin ThO2 target, especially prepared for fission measurements at n_ToF, CERN during its first phase of operations, using the painting technique. The masses of all actinide samples were determined via α-spectroscopy. The produced fission yields along with the results obtained from activation foils were studied in parallel, using both the NeusDesc [1] and MCNP5 [2] codes, taking into consideration competing nuclear reactions (e.g. deuteron break up), along with neutron elastic and inelastic scattering with the beam line, detector housing and experimental hall materials. Since the 232Th(n,f) reaction has a relatively low energy threshold and can thus be affected by parasitic neutrons originating from a variety of sources, the thorough characterization of the neutron flux impinging on the targets is a prerequisite for accurate cross-section measurements, especially in the absence of time-of-flight capabilities. Additional Monte-Carlo simulations were also performed coupling both GEF [3] and FLUKA [4] codes for the determination of the detection efficiency.

scholarly journals Understanding the Incremental Impact of Built Environment on Climate Change of Metropolitan City Karachi

2020 ◽  
Vol 39 (4) ◽  
pp. 678-685
Author(s):  
Nimra Kanwal ◽  
Nuhzat Khan
Keyword(s):  
Climate Change ◽  
Energy Consumption ◽  
Residential Buildings ◽  
Building Design ◽  
High Energy ◽  
Metropolitan City ◽  
Green Area ◽  
The World ◽  
The Impact ◽  
The City

Buildings are the most important part of development activities, consumed over one-thirds of the global energy. Household used the maximum energy around the world, likewise in Pakistan residential buildings consumed about half of total energy (45.9% per year). The study aims to analyze the impact of building design on climate of Metropolitan City Karachi, Pakistan and to evaluate the change in urbanization patterns and energy consumption in the buildings. To have better understanding of the issues correlations was established amongst population, urbanization patterns, green area, number of buildings (residential and commercial), building design, energy consumption and metrological records (climate change parameters) by collecting the data from the respective departments. With the help of the collected data amount of carbon dioxide was estimated. The results reveled that during last 36 years the urban population of Karachi increased exponentially from 5,208,000 (1981) to 14,737,257 (2017) with increase in urbanized area from 8.35 km2 (1946) to 3,640 km2 (2017) that may led to reduce the green area of the city from 495,000 hectors (1971) to 100,000 hectors (2015). Moreover, the building’s design and numbers are being changed from 21 high-rise buildings (2009) to 344 (2017). It may be concluded that change in temperature pattern and climatic variability of the city may be due to increase in population and change in lifestyle that lead to high energy consumption that is prime source of increased in CO2 emission in the environment of Karachi city, However, Greenhouse Gases (GHG) releases are much lower than the levels reported from metropolitan cities around the world.

Barriers to Adoption of Commercial Green Buildings in India: A Review

2021 ◽  
pp. 097493062110584
Author(s):  
Sayani Saha ◽  
Rahul B Hiremath ◽  
Sanjay Prasad ◽  
Bimlesh Kumar
Keyword(s):  
Developing Countries ◽  
Green Building ◽  
High Energy ◽  
Jel Classification ◽  
Policy Framework ◽  
Future Research ◽  
Extensive Literature ◽  
Construction Sector ◽  
Environmental Aspect ◽  
The World

The global construction sector accounts for 13.2% of the world’s gross domestic product (GDP). It not only contributes to the economic growth engine of the world but also climate changes due to its high energy footprint. Sustainable buildings have the potential to reduce the adverse impacts of the construction industry, but their adoption is slow due to hindrances. The aim of this paper is to study literature on barriers to green building adoption to date and highlight the overlapping and unique barriers specific to India in comparison to a few prominent countries, and provide solutions and recommendations for future research. The methodology has been an extensive literature review of the barriers to green building (GB) adoption. The key findings, namely barriers, were classified under economic, governmental, organizational and social perception, information, technology and material categories. Barriers unique to India and a few other developing countries are an extension of project schedules, lack of research and developmental works, lack of public motivation, poor building code enforcement, high payback period, uncertain supply of green materials, improper implementation of policy framework and performance of green building technologies (GBT’s). The GB construction sector is fragmented around the world. Even the GB definition is not the same across the globe although the environmental aspect is the same. Similarly, there are unique and overlapping challenges in GB adoption globally. Buildings in usage perspectives can be classified into residential and non-residential. This study looks only at non-residential GBs due to their homogenous nature. There is a dearth of specific studies related to the adoption of GBs in India. This study aims to fulfil the gap of India’s standing in the barriers to GB adoption with respect to the developed and developing countries. JEL Classification: I18

Sign in / Sign up

Export Citation Format

Share Document