scholarly journals HMX detonation calculation using multi-reaction chain

2020 ◽  
Author(s):  
Chong Chang ◽  
Anthony Scannapieco
Keyword(s):  
Reaction Chain

scholarly journals Review and Assessment of the Effect of Hydrogen Gas Pressure on the Embrittlement of Steels in Gaseous Hydrogen Environment

Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 637
Author(s):  
Thorsten Michler ◽  
Ken Wackermann ◽  
Frank Schweizer
Keyword(s):  
Hydrogen Gas ◽  
Gaseous Hydrogen ◽  
Gas Pressure ◽  
Data Sets ◽  
Large Set ◽  
Test Parameter ◽  
Rate Limiting ◽  
Important Test ◽  
Pressure Hydrogen ◽  
Reaction Chain

Hydrogen gas pressure is an important test parameter when considering materials for high-pressure hydrogen applications. A large set of data on the effect of hydrogen gas pressure on mechanical properties in gaseous hydrogen experiments was reviewed. The data were analyzed by converting pressures into fugacities (f) and by fitting the data using an f|n| power law. For 95% of the data sets, |n| was smaller than 0.37, which was discussed in the context of (i) rate-limiting steps in the hydrogen reaction chain and (ii) statistical aspects. This analysis might contribute to defining the appropriate test fugacities (pressures) to qualify materials for gaseous hydrogen applications.

scholarly journals Reaction chain modeling of denitrification reactions during a push–pull test

2013 ◽  
Vol 148 ◽  
pp. 1-11 ◽  
Author(s):  
A. Boisson ◽  
P. de Anna ◽  
O. Bour ◽  
T. Le Borgne ◽  
T. Labasque ◽  
...  
Keyword(s):  
Pull Test ◽  
Reaction Chain

Critical conditions in neutron multiplication

1939 ◽  
Vol 35 (4) ◽  
pp. 610-615 ◽  
Author(s):  
R. Peierls
Keyword(s):  
Nuclear Reaction ◽  
Critical Conditions ◽  
Single Neutron ◽  
Neutron Multiplication ◽  
Secondary Neutrons ◽  
Reaction Chain

It is well known that a single neutron may cause a nuclear reaction chain of considerable magnitude, if it moves in a medium in which the number of secondary neutrons which are produced by neutron impact is, on the average, greater than the number of absorbed neutrons. From recent experiments it would appear that this condition might be satisfied in the case of uranium.

C. Abnormal rituals in stress situations the rigidification of behaviour

1966 ◽  
Vol 251 (772) ◽  
pp. 327-330 ◽  
Keyword(s):  
Las Vegas ◽  
Basic Fact ◽  
Nest Material ◽  
Laboratory Studies ◽  
Action Pattern ◽  
The Past ◽  
Animal Psychology ◽  
The Relationship ◽  
Skinner Box ◽  
Reaction Chain

Behaviour sequences commonly consist of highly variable appetitive phases leading to rather fixed consummatory acts. Action-pattern rigidity is typical of the terminal moments of a reaction chain. This basic fact is all too often obscured by the artificial conditions of behaviour studies. Observations on laboratory or captive animals tend to conceal the degree of variability of the earlier phases of each sequence. The simplicity and sterility of the unnatural environment offered to the animal causes differential damage to its motoric performance, attacking the early stages more and the later stages less. A caged animal will feed, drink, nest and copulate, but it cannot set off on lengthy quests for food, water, nest material or a mate. Notorious laboratory devices such as the Skinner-box have served to eliminate totally any possibility for motoric variability. The emphasis in laboratory studies of this kind has been steadfastly concentrated on the variability in the relationship between simple stimuli and an artificially rigidified response. Although the study of this (SR) relationship is an important aspect of animal psychology, it is extremely misleading to overstress its importance as has been done so often in the past. To equate it with the whole topic of animal behaviour is like claiming that the gaming rooms of Las Vegas reflect the whole of human endeavour.

scholarly journals PENYEBARAN DAN DETEKSI MOLEKULER VIRUS GEMINI PENYEBAB PENYAKIT KUNING PADA TANAMAN CABAI DI SUMATERA

2005 ◽  
Vol 5 (2) ◽  
pp. 113-121
Author(s):  
Sudiono Sudiono ◽  
Nur Yasin ◽  
Sri Hendrastuti Hidayat ◽  
Purnama Hidayat
Keyword(s):  
Molecular Detection ◽  
Sumatra Island ◽  
West Sumatra ◽  
Yellowing Disease ◽  
North Sumatra ◽  
Reaction Chain

The distribution and molecular detection of geminivirus pathogen of chilli yellowing disease in Sumatera lsland.  The objective of this research was to investigate the spread and to detect geminivirus in Sumatra Island.  The method is survey infected of plants in  Province of Lampung, South Sumatra, Bengkulu, Jambi, West Sumatra, and North Sumatra was used to detection of geminivirus from collected chilli plants by PCR (polymerase reaction chain) technique. The result showed that based on typical symptoms and molecular detection of collected sample from Lampung, South Sumatera, and North Sumatera were infected by geminivirus. The type symptoms were turning yellowing, curling, and stunting. Occurrence of disease accidents were for Province of Lampung 0 - 100%, South Sumatra 20 - 60%, Bengkulu 0 - 40%, Jambi 0 - 5%, West Sumatra 0 - 5% and North Sumatra 0 – 80%, while sample Province of Jambi and of West Sumtera were not infected by geminivirus based on symptoms and molecular detection.

scholarly journals Exploring the Risk Factors of Infrastructure PPP Projects for Sustainable Delivery: A Social Network Perspective

2020 ◽  
Vol 12 (10) ◽  
pp. 4152 ◽  
Author(s):  
Yan Wang ◽  
Yujie Wang ◽  
Xiuyu Wu ◽  
Jiwang Li
Keyword(s):  
Risk Factors ◽  
Risk Factor ◽  
Social Network ◽  
Credit Rating ◽  
Legal Change ◽  
Structured Interviews ◽  
Chain Reactions ◽  
Financing Risk ◽  
Government Credit ◽  
Reaction Chain

Due to the relatively long period and large capital flow of public-private partnership (PPP) projects, PPP participants are faced with a complex risk situation impeding the sustainable project delivery. In recent years, risk management of PPP projects has received increasing attention. In this paper, twenty risk factors associated with infrastructure PPP projects were identified by literature review and in-depth case studies. Relationship data for these twenty typical risk factors were obtained through structured interviews. Based on the obtained data, the risk relationship network within infrastructure PPP projects was identified, and the network structure characteristics were analyzed, including individual node attributes and the influence and cohesion of subgroups. The results indicate that key risk factor nodes can form a reaction chain via bridge nodes that can trigger a risk domino effect within PPP projects. Specifically, the key risk factors of PPP projects are divided into two categories, the first of which include risk factors that have powerful and independent influence, such as delay in government approval, government credit, and imperfect legal and regulatory systems. The second category includes risk factors that are highly vulnerable and easily influenced, such as completion risks, insufficient revenue in the market, and fee change. A key risk factor reaction chain is one in which legal change leads to a decline in government credit rating, triggering a contract risk. Twelve bridge nodes were identified that play an important intermediary role in the network, e.g., legal change, public objection, and financing risk. This paper extends the application of social network analysis in PPP projects management research and identifies the key risk factors and crucial factors influencing chain reactions in PPP projects. The results provide a more in-depth understanding of sustainable PPP project management for government agencies and private enterprises.

The Quantum Yield of Oxidation of Hevea Rubber and GR-S

1948 ◽  
Vol 21 (3) ◽  
pp. 639-653 ◽  
Author(s):  
E. J. Hart ◽  
M. S. Matheson
Keyword(s):  
Quantum Yield ◽  
Room Temperature ◽  
Wave Length ◽  
Radical Reaction ◽  
Quantum Yields ◽  
Initial Reaction ◽  
Free Radical Reaction ◽  
Stable Intermediate ◽  
A Chain ◽  
Reaction Chain

Abstract The initial quantum yields of photoöxidation for purified Hevea rubber have been measured for various mercury arc lines in the wave length region 2537– 17,400 A˚. All experiments were carried out at room temperature and at an oxygen pressure of one atmosphere. At the outset of irradiation all quantum yields of combined oxygen are less than unity, although the quantum efficiency rises above 1.0 at 2537 and 3130 A˚. as photoöxidation proceeds. The low quantum yield suggests that in its initial stages (less than 0.1 per cent oxygen combined on the rubber) photoöxidation is not a chain reaction. It is postulated as the first step in rubber photoöxidation that the light activated rubber group reacts with oxygen to give a relatively stable intermediate which does not immediately dissociate to give a free radical reaction chain. The quantum yields of photoöxidation of purified GR-S were also measured under the same conditions as used for rubber. At each wave length the quantum yield was lower than for rubber, indicating formation of a stable intermediate in the initial reaction also.

scholarly journals Kinetic aspects of chain growth in Fischer–Tropsch synthesis

2017 ◽  
Vol 197 ◽  
pp. 153-164 ◽  
Author(s):  
Ivo A. W. Filot ◽  
Bart Zijlstra ◽  
Robin J. P. Broos ◽  
Wei Chen ◽  
Robert Pestman ◽  
...  
Keyword(s):  
Conversion Rate ◽  
Critical Role ◽  
Chain Growth ◽  
Fischer Tropsch ◽  
Co Conversion ◽  
Chain Growth Probability ◽  
Hydrocarbon Chains ◽  
Surface Intermediates ◽  
Reaction Chain ◽  
Growth Probability

Microkinetics simulations are used to investigate the elementary reaction steps that control chain growth in the Fischer–Tropsch reaction. Chain growth in the FT reaction on stepped Ru surfaces proceeds via coupling of CH and CR surface intermediates. Essential to the growth mechanism are C–H dehydrogenation and C hydrogenation steps, whose kinetic consequences have been examined by formulating two novel kinetic concepts, the degree of chain-growth probability control and the thermodynamic degree of chain-growth probability control. For Ru the CO conversion rate is controlled by the removal of O atoms from the catalytic surface. The temperature of maximum CO conversion rate is higher than the temperature to obtain maximum chain-growth probability. Both maxima are determined by Sabatier behavior, but the steps that control chain-growth probability are different from those that control the overall rate. Below the optimum for obtaining long hydrocarbon chains, the reaction is limited by the high total surface coverage: in the absence of sufficient vacancies the CHCHR → CCHR + H reaction is slowed down. Beyond the optimum in chain-growth probability, CHCR + H → CHCHR and OH + H → H2O limit the chain-growth process. The thermodynamic degree of chain-growth probability control emphasizes the critical role of the H and free-site coverage and shows that at high temperature, chain depolymerization contributes to the decreased chain-growth probability. That is to say, during the FT reaction chain growth is much faster than chain depolymerization, which ensures high chain-growth probability. The chain-growth rate is also fast compared to chain-growth termination and the steps that control the overall CO conversion rate, which are O removal steps for Ru.

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