scholarly journals Mass Transfer Behavior and Microstructure Evolution of Li4TiO4-Li2TiO3 Core-shell Breeding Ceramic Under Harsh Operating Conditions

2021 ◽  
Author(s):  
Ruichong Chen ◽  
Kazunari Katayama ◽  
Jianqi Qi ◽  
Akito Ipponsugi ◽  
Ran Oyama ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Mass Loss ◽  
Point Of View ◽  
Operating Conditions ◽  
Heating Process ◽  
Core Shell ◽  
Tritium Breeding ◽  
Long Time ◽  
Transfer Behavior

Abstract The development of novel tritium breeding materials was urgently needed in order to continuously optimize the tritium breeding ratio (TBR) of thermonuclear fusion reactors. From this point of view, Li4TiO4-Li2TiO3 core-shell breeding materials with more reasonable structure and theoretical Li density of 0.464 g/cm3 were prepared in this work. Notably, the mass transfer experiment at 900 °C in 1% H2/Ar shows that the theoretical Li density of this core-shell material after heating for 30 days was significantly higher than that of other breeding materials, indicating that it can provide more stable and efficient TBR. Specifically, the Li mass loss of the sample after 30 days heating was 3.4%, resulting in a decrease of Li density to 0.415 g/cm3. The mechanism of Li mass loss in Li4TiO4-Li2TiO3 core-shell breeding materials was investigated in detail. Moreover, the samples did not crack or collapse during the long-term heating process, and always maintained a satisfactory crushing load, revealing that this core-shell breeding ceramic can be used for a long time under severe operating conditions.

scholarly journals The Theory of Novae and Nova-Like Systems

1974 ◽  
Vol 66 ◽  
pp. 155-167
Author(s):  
John Faulkner
Keyword(s):  
Mass Transfer ◽  
Angular Momentum ◽  
Mass Loss ◽  
Gravitational Radiation ◽  
Theoretical Work ◽  
Observational Evidence ◽  
Recent Theoretical Work ◽  
Term Response ◽  
Theoretical Developments

Recent observational and theoretical developments in the study of novae, particularly dwarf novae, are discussed. Mechanisms promoting mass transfer include (i) nuclear evolution or (ii) envelope instability of the red star and (iii) gravitational radiation of orbital angular momentum. Growing observational evidence against (ii) is supported by recent theoretical work on the medium and long term response of stellar radii to mass loss. Mechanisms (i) and (iii) may operate alone or in concert, depending on the circumstances.

scholarly journals Costs in the Marketing Planning System at the Enterprise

2020 ◽  
pp. 182-189
Author(s):  
Valentyn Korinyev ◽  
◽  
Serhii Romanchuk ◽  
Svitlana Boiko ◽  
◽  
...  
Keyword(s):  
Production Efficiency ◽  
Swot Analysis ◽  
Point Of View ◽  
Operating Conditions ◽  
Planning System ◽  
Pricing Policy ◽  
Business Units ◽  
Marketing Planning ◽  
Marketing Activities

The problem of planning of marketing activity of domestic enterprises is defined and its features are investigated. An algorithm for the process of planning marketing activities according to the results of this study is proposed. The role of costs from the point of view of pricing at marketing planning is specified. It is established that the key to the success of the enterprise in modern conditions is the planning of its marketing activities, taking into account the peculiarities of the micro and macro environment. It is important for the company to pay attention to reducing marketing risks by reducing the uncertainty of operating conditions and concentration of resources in the most promising areas. Therefore, the company tries to reduce the level of risk in both long-term and short-term, developing and implementing strategic and tactical planning measures.Considerable attention should be paid to the level of costs for production and sales. This will achieve the goals set by the company and will improve the sales of the company's products and increase its profits. It is advisable to conduct a SWOT-analysis of the strengths and weaknesses of the enterprise and apply a matrix of varieties of its strategic business units. In all areas and at all levels of planning the marketing activities of the enterprise requires the preparation and streamlining of decisions about the goals, means and measures that should ensure the production and sale of products that meet existing demand and future consumer needs. With such marketing planning, this will allow the company to decide on its pricing policy in order not to lose old and attract new customers, which will achieve production efficiency and product competitiveness.

scholarly journals Secular Evolution of Cataclysmic Variables with Irradiation-Induced Mass Transfer

1996 ◽  
Vol 158 ◽  
pp. 449-452 ◽  
Author(s):  
H. Ritter ◽  
Z. Zhang ◽  
J. M. Hameury
Keyword(s):  
Mass Transfer ◽  
Cataclysmic Variables ◽  
Point Of View ◽  
External Irradiation ◽  
General Point ◽  
Mass Star ◽  
Compact Binaries ◽  
Secular Evolution ◽  
Low Mass

The possible importance of the reaction of a low-mass star to external irradiation for the long-term evolution of compact binaries has been noted only rather recently; first in the context of the evolution of low-mass X-ray binaries (e.g. Podsiadlowski 1991; Harpaz & Rappaport 1991; Frank, King & Lasota 1992; Hameury et al. 1993) and subsequently by Ritter, Zhang & Kolb (1995a,b, hereafter RZK) also for the evolution of cataclysmic variables (CVs). Based on a simple model for describing the reaction of a low-mass star to irradiation RZK showed that CVs can be dynamically unstable against irradiation-induced mass transfer and that, as a consequence of this, mass transfer could occur via cycles in which phases of high, irradiation-enhanced mass transfer alternate with phases of little or no mass transfer. The occurrence of such mass transfer cycles in CVs was subsequently discussed from a more general point of view by King (1995) and King et al. (1995). Whereas the possibility of mass transfer cycles in CVs is now fully recognised, the question as to which systems can undergo such cycles and which cannot has not yet been addressed in detail. It is the purpose of this contribution to provide at least a partial answer to this question.

Optimization of Wear Parameters Considering Specific Energy Equivalence during Two-body Abrasion of ‘EPDM’ Rubber

2013 ◽  
Vol 13 (4) ◽  
pp. 233-238
Author(s):  
Abhijit Mukhopadhyay
Keyword(s):  
Mass Loss ◽  
Specific Energy ◽  
Real Life ◽  
Point Of View ◽  
Operating Conditions ◽  
Epdm Rubber ◽  
Energy Equivalence ◽  
Application Potential ◽  
Major Application ◽  
Noise Factors

AbstractWith several renewed and advanced researches in the recent past rubber, a viscoelastic material, emerges as a very suitable and important material for various engineering and other applications. EPDM rubber, one of the dominant elastomer, has a major application as seal in automobile doors, windows and other parts along with different other uses. Rubbers, in general have good abrasion resistance. But abrasion will lead to the impairment of the desired function of the components. Thus, the evaluation of abrasion, whatever small may be, is important.In the present work mere mass loss has not been considered as a measure of abrasion. On the contrary, an ideal function, specific energy has been modeled utilizing the concept of grinding operation. Abrasion has been interpreted in terms of specific energy. The modeled ideal function can be interpreted in two different ways. If abrasion, that is, mass loss is to be minimized then the specific energy of the material should have maximum value. Otherwise, from energy perspective, if the energy is to be minimized then more material must have to be removed in a single pass thus maximizing the mass loss. However, in the present work the objective is to understand the operating conditions which will give minimum loss of EPDM rubber when abrasion takes place. This theoretical study is a part of characterization of EPDM rubber from tribological point of view and primarily based on controlled laboratory experimentation conditions. It is need less to be mentioned that in real life applications the noise factors, as have been selected for the study, are beyond control in that sense and thus abrasion of EPDM can't be predicted through this model. However, in case of automated door and window locking system of automobiles, metros etc. this model will have some meaningful application potential.

scholarly journals Biological treatment of water contaminated by hydrocarbons in three-phase gas-liquid-solid fluidized bed

2013 ◽  
Vol 8 (1) ◽  
pp. 9-15
Keyword(s):  
Mass Transfer ◽  
Fluidized Bed ◽  
Biological Treatment ◽  
Plug Flow ◽  
Point Of View ◽  
Operating Conditions ◽  
Solid Particles ◽  
Hydrodynamic Characteristics ◽  
Intimate Contact ◽  
Three Phase

Biological treatment has been carried out in two different systems: aerated closed and threephase fluidized bed reactors for hydrocarbons removal from refinery wastewaters. For the two systems, hydrodynamic study allowed the determination of operating conditions before treatment experiments. Then, in a second time, biological treatments have been conducted in the same operating conditions. The obtained results showed that in the three-phase fluidized bed we can degrade hydrocarbons more rapidly than in a closed aerated bioreactor. Among the different appropriate techniques available to create efficient contacts between phases, the three-phase fluidization G/L/S where carrier particles are moving inside the reactor seems very interesting. It allows an intimate contact between phases and present many advantages concerning hydrodynamic and mass transfer phenomena. In fact, depending on operating conditions and the bubble flow behaviour, the three-phase fluidized bed could display different flow regimes In these systems called bioreactors the solid particles covered with a biofilm are fluidized by two ascending flows of air and contaminated water. With favourable operating conditions, from a hydrodynamic and mass transfer point of view, the pollutant can be biologically degraded up to 90%. Until this date, the three-phase bioreactors modelling remains very complex because it required taking into account several factors: the pollutant biodegradation rate in the biofilm, the bioreactor hydrodynamic characteristics, and the reactant interfacial gas-liquid and liquidsolid mass transfer. Thus the essential purpose of modelling is to integrate the microbial kinetics with the reactor hydrodynamics. We can notice that a few models have incorporated both bioreactor hydrodynamics and microbial kinetics. For the steady state bioreactor model, we generally assume that the particles are uniform in size, the biofilm is uniform in thickness, and the biofilm can be considered as homogeneous matrix through which oxygen and substrate diffuse and are consumed by the microbes. The liquid phase in the bioreactor substrate is considered to be axially dispersed while the gas phase is assumed to be in plug flow [2]. Rittmann (1997) proposed a model based on wake theory for predicting bed expansion and phase hold-ups for three-phase fluidized bed bioreactors. In this model he modified the correlation for the computation of the bioparticles drag coefficient CD [3]. He also attempted to explain the biofilm detachment which can occur with three broad patterns: erosion, sloughing and scouring and assumed that the factors affecting detachment rates can be grouped into two categories (physical forces and microorganisms physiology in the biofilm).

scholarly journals Release of 14C and 3H from Irradiated Graphite of the Thermal Column of VVR-S Reactor to Solution Phase

Radiocarbon ◽  
2018 ◽  
Vol 60 (6) ◽  
pp. 1831-1837 ◽  
Author(s):  
Viorel Fugaru ◽  
Cristian Postolache ◽  
George Bubueanu ◽  
Catalin Tuta
Keyword(s):  
Reactor Core ◽  
Point Of View ◽  
Solution Phase ◽  
Fuel Cladding ◽  
Time Prediction ◽  
Irradiated Graphite ◽  
Thermal Column ◽  
Activation Products ◽  
Long Time

ABSTRACTGenerally, 14C is produced in all types of reactors, mainly through neutron-induced reactions with isotopes of carbon, nitrogen, and oxygen. These isotopes are present in the fuel, fuel cladding, coolant, moderator, and structural materials of the reactor. Irradiated graphite contains a range of activation products but, from the point of view of geological disposal, another radionuclide which has to be taken into account is tritium (3H or T), produced through the neutron induced reaction Li(n,α)T. In this study we have investigated the release of 14C and 3H into the solution phase from two intact samples of irradiated graphite which have been cut from the thermal column disc located near the VVR-S reactor core. To evaluate 14C and 3H long-term release in solution the graphite samples were submerged in a solution of 0.1 M of sodium hydroxide. The experimental results regarding the release of 14C and 3H from VVR-S irradiated graphite to liquid phase show that a major fraction of the total release occurs in the first months and a slower release on a long time scale. However, these results should be applied cautiously for long time prediction.

scholarly journals Differenziali geografici di sviluppo

2013 ◽  
Author(s):  
Francesco Dini
Keyword(s):  
Twentieth Century ◽  
Economic Development ◽  
Formation Process ◽  
Political Economics ◽  
The State ◽  
Point Of View ◽  
Human Behaviour ◽  
Long Time ◽  
Geographical Point

Geographical differentials of development derive from regional specializations. As classical political economics advised, they are what actively or passively create, and each one with more or less intensity, inter-regional commerce and the nations' different capacities to produce wealth. It is not only through categories of the economy that this capacity can be interpreted: equally as salient factors are the eco-system conditions, cultures and the state formation process. But it is true that the market for a long time has been the form of organization of human behaviour aimed at creating surplus within which this capacity is expressed, distinctly takes shape and gradually builds different pictures from that, since the second half of the twentieth century, usually defined as «economic development». The different capacity of places to produce wealth, in the same way as regional specializations, is indeed subject to endless evolution; the process is long term, very long term, and is characterized by clear but changing geographical regularities, within which moments of accelerated change can yet also be seen. By observing it from a geographical point of view, this work tries to fit the pieces back together, starting from the advent of so-called «capitalism» and going onto look at the logic and rules of the current configurations.

scholarly journals Welfare Aspects of Raising Entire Male Pigs and Immunocastrates

Animals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 2140
Author(s):  
Eberhard Borell ◽  
Michel Bonneau ◽  
Mirjam Holinger ◽  
Armelle Prunier ◽  
Volker Stefanski ◽  
...  
Keyword(s):  
Environmental Enrichment ◽  
Scientific Literature ◽  
Point Of View ◽  
Current Status ◽  
Climate Control ◽  
Housing Systems ◽  
Group Stability ◽  
Long Time ◽  
Entire Male

For a long time, scientists assumed that newborns have a severely limited sense of pain (if any). However, this assumption is wrong and led to a “start of the exit” from piglet surgical castration. Some of the currently discussed or already implemented alternatives such as general or local anaesthesia during surgical castration raise additional welfare concerns as well as legal problems and/or are hardly applicable. The favoured long-term, welfare-friendly “gold standard” is to raise entire male pigs (EM). However, this may also impose certain welfare problems under the current conventional housing and management conditions. The specific types of behaviour displayed by EM such as mounting and aggressive behaviours but also increased exploration, which are partially linked to sexual maturation, increase the risk for injuries. The current status of knowledge (scientific literature and farmer experiences) on housing of EM suggests that environmental enrichment, space, group-stability, social constellation, feeding (diet and feeder space), health and climate control are critical factors to be considered for future housing systems. From an animal welfare point of view, an intermediate variant to be favoured to reduce problematic behaviour could be to slaughter EM before reaching puberty or to immunize boars early on to suppress testicular function. Immunization against endogenous GnRH can reduce EM-specific problems after the 2nd vaccination.

scholarly journals Aspects Regarding the Energy Security in the Middle East

2017 ◽  
Vol 22 (2) ◽  
pp. 85-93
Author(s):  
Ionuţ Alin Cîrdei
Keyword(s):  
Middle East ◽  
Energy Security ◽  
Transport Process ◽  
Point Of View ◽  
Oil Price ◽  
Energy Resources ◽  
Middle East Countries ◽  
Long Time

Abstract Ensuring energy security is a concern for all the world’s countries. For a long time, the issue of energy security has been looked at from the point of view of ensuring the energy resources necessary for the functioning of the economy and society and, implicitly, from the perspective of reducing dependence on imported energy resources. In reality, however, energy security must also be addressed from the perspective of states with energy resources, as their security can be jeopardized by disturbances that may occur during the operation or transport process or due to lower prices. Middle East countries, rich in energy resources, are currently vulnerable due to global oil price declines and instability and conflict in the region. This vulnerability may affect the supply of energyconsuming states and their energy security in the medium and long term, and not only.

scholarly journals The Role of Gravitational Radiation in the Evolution of Dwarf Novae

1974 ◽  
Vol 64 ◽  
pp. 97-97 ◽  
Author(s):  
John Faulkner
Keyword(s):  
Mass Transfer ◽  
Angular Momentum ◽  
Mass Loss ◽  
Gravitational Radiation ◽  
Theoretical Work ◽  
Observational Evidence ◽  
Recent Theoretical Work ◽  
Term Response

Mechanisms promoting mass transfer include (i) envelope instability or (ii) nuclear evolution of the red star and (iii) gravitational radiation of orbital angular momentum. Growing observational evidence against (i) is supported by recent theoretical work on the medium and long-term response of stellar radii to mass-loss (Eggleton, Faulkner and Webbink, in progress). Since (ii) is in most cases too slow a process, (iii) is left as the best surviving explanation.

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