Impurity leakage and radiative cooling in the first nitrogen and neon seeding study in the slot divertor at DIII-D

2021 ◽  
Author(s):  
Livia Casali ◽  
David Eldon ◽  
Adam G McLean ◽  
Tom H Osborne ◽  
Anthony W Leonard ◽  
...  
Keyword(s):  
Experimental Studies ◽  
Mean Free Path ◽  
Flow Reversal ◽  
Momentum Balance ◽  
Ionization Source ◽  
Power Flux ◽  
Impurity Transport ◽  
Plasma Drifts ◽  
High Level ◽  
The Impact

Abstract A comparative study of nitrogen versus neon has been carried out to analyze the impact of the two radiative species on power dissipation, SOL impurity distribution, divertor and pedestal characteristics. The experimental results show that N remains compressed in the divertor, thereby providing high radiative losses without affecting the pedestal profiles and displacing carbon as dominant radiator. Neon, instead, radiates more upstream than N thus reducing the power flux through the separatrix leading to a reduced ELM frequency and compression in the divertor. A significant amount of neon is measured in the plasma core leading to a steeper density gradient. The different behaviour between the two impurities is confirmed by SOLPS-ITER modelling which for the first time at DIII-D includes multiple impurity species and a treatment of full drifts, currents and neutral-neutral collisions. The impurity transport in the SOL is studied in terms of the parallel momentum balance showing that N is mostly retained in the divertor whereas Ne leaks out consistent with its higher ionization potential and longer mean free path. This is also in agreement with the enrichment factor calculations which indicate lower divertor enrichment for neon. The strong ionization source characterizing the SAS divertor causes a reversal of the main ions and impurity flows. The flow reversal together with plasma drifts and the effect of the thermal force contribute significantly in the shift of the impurity stagnation point affecting impurity leakage. This work provides a demonstration of the impurity leakage mechanism in a closed divertor structure and the consequent impact on pedestal. Since carbon is an intrinsic radiator at DIII-D, in this paper we have also demonstrated the different role of carbon in the N vs Ne seeded cases both in the experiments and in the numerical modeling. Carbon contributes more when neon seeding is injected compared to when nitrogen is used. Finally, the results highlight the importance of accompanying experimental studies with numerical modelling of plasma flows, drifts and ionization profile to determine the details of the SOL impurity transport as the latter may vary with changes in divertor regime and geometry. In the cases presented here, plasma drifts and flow reversal caused by high level of closure in the slot upper divertor at DIII-D play an important role in the underlined mechanism.

Asymptotically matched sheath and presheath in a dense plasma

1998 ◽  
Vol 59 (3) ◽  
pp. 505-536 ◽  
Author(s):  
LINDSEY D. THORNHILL ◽  
PRATEEN V. DESAI
Keyword(s):  
Rapid Change ◽  
Debye Length ◽  
Mean Free Path ◽  
Boundary Region ◽  
Surface Erosion ◽  
Leading Order ◽  
Power Flux ◽  
Temperature Plasma ◽  
Recombination Length ◽  
The Impact

Asymptotically matched solutions for electron and ion density, electron and ion velocity, and electric potential are obtained in the boundary region of a dense low-temperature plasma adjacent to perfectly absorbing walls – walls that absorb, without reflection, incident electrons and ions. Leading-order composite solutions, valid throughout the boundary region, are constructed from solutions in three subdomains distinguished by different physical length scales: the geometric length, the ion mean free path and the Debye length. The composite solutions are used to assess the impact of electron–ion recombination in the ionization nonequilibrium region on sheath and presheath profiles, and on quantities evaluated at the wall. While, at leading order, the velocity profiles throughout the boundary region are not influenced by recombination, the density and potential profiles are significantly altered when recombination is included. These results show that the region of rapid change in these profiles lies closer to the wall when recombination is explicitly included in the model. The influence of recombination on the presheath potential, and consequently the wall potential, is found to scale as the natural logarithm of the recombination length. The broadening of the density profile results in a larger flux of ions accelerating through the sheath and impacting on the wall. The influence of recombination on the ion power flux to the wall is found to scale with the inverse recombination length. This scaling influences the prediction of surface erosion rates in technological applications that utilize these plasmas.

Sluice Gate Discharge From Momentum Balance

2021 ◽  
Author(s):  
Michael Steppert ◽  
Philipp Epple ◽  
Andreas Malcherek
Keyword(s):  
Control Volume ◽  
Experimental Studies ◽  
Momentum Balance ◽  
Balance Theory ◽  
Scaling Effects ◽  
Sluice Gate ◽  
Friction Forces ◽  
Flow Effects ◽  
3D Effect ◽  
The Impact

Abstract Discharge from sluice gate flows is commonly calculated using the Torricelli outflow velocity, which is inaccurate and must be corrected by a discharge coefficient. Moreover, this approach commonly only considers the relative gate opening, without including the impact of 3D effects, scaling effects, different velocity profiles and friction forces. Aiming for a theoretical approach that can address all flow effects for sluice gate discharge calculations, the authors applied the momentum balance theory to this problem. First the control volume was introduced and parameterization equations for the pressure distributions and momentum coefficients at the control volume borders for both the standard and the inclined sluice gates were determined using CFD simulations. The results show good agreements with the discharge measurement results of frequently quoted experimental studies from other authors, demonstrating the potential of this approach. Also, one example of the impact of the 3D effect of various channels widths was investigated with the momentum balance theory.

ПРАГМАТИЧНИЙ ПОТЕНЦІАЛ НАТИВНОЇ РЕКЛАМИ: ФОРМИ, ТРЕНДИ (НА ПРИКЛАДІ НАТИВНОГО КОНТЕНТУ В СОЦІАЛЬНІЙ МЕРЕЖІ FACEBOOK ЩОДО БРЕНДА ФАКУЛЬТЕТУ ЖУРНАЛІСТИКИ ЗНУ)

2020 ◽  
pp. 113
Author(s):  
V. Kovpak ◽  
N. Trotsenko
Keyword(s):  
Social Network ◽  
Professional Training ◽  
Educational Process ◽  
Communication Strategy ◽  
Student Centered ◽  
Teacher Student ◽  
The Social ◽  
National University ◽  
High Level ◽  
The Impact

<div><p><em>The article analyzes the peculiarities of the format of native advertising in the media space, its pragmatic potential (in particular, on the example of native content in the social network Facebook by the brand of the journalism department of ZNU), highlights the types and trends of native advertising. The following research methods were used to achieve the purpose of intelligence: descriptive (content content, including various examples), comparative (content presentation options) and typological (types, trends of native advertising, in particular, cross-media as an opportunity to submit content in different formats (video, audio, photos, text, infographics, etc.)), content analysis method using Internet services (using Popsters service). And the native code for analytics was the page of the journalism department of Zaporizhzhya National University on the social network Facebook. After all, the brand of the journalism department of Zaporozhye National University in 2019 celebrates its 15th anniversary. The brand vector is its value component and professional training with balanced distribution of theoretical and practical blocks (seven practices), student-centered (democratic interaction and high-level teacher-student dialogue) and integration into Ukrainian and world educational process (participation in grant programs).</em></p></div><p><em>And advertising on social networks is also a kind of native content, which does not appear in special blocks, and is organically inscribed on one page or another and unobtrusively offers, just remembering the product as if «to the word». Popsters service functionality, which evaluates an account (or linked accounts of one person) for 35 parameters, but the main three areas: reach or influence, or how many users evaluate, comment on the recording; true reach – the number of people affected; network score – an assessment of the audience’s response to the impact, or how far the network information diverges (how many share information on this page).</em></p><p><strong><em>Key words:</em></strong><em> nativeness, native advertising, branded content, special project, communication strategy.</em></p>

THE IMPACT OF UKRAINE'S EXCISE DUTY POLICY ON THE TRANSFORMATION PROCESSES OF THE TOBACCO MARKET

2020 ◽  
Vol 2020 (10) ◽  
pp. 19-33
Author(s):  
Nadiia NOVYTSKA ◽  
◽  
Inna KHLIEBNIKOVA ◽  
Keyword(s):  
Structural Changes ◽  
Tax Avoidance ◽  
Transformation Process ◽  
State Regulation ◽  
Tobacco Products ◽  
Excise Duty ◽  
Increasing Demand ◽  
High Level ◽  
The Impact ◽  
Transformation Processes

The market of tobacco products in Ukraine is one of the most dynamic and competitive. It develops under the influence of certain factors that cause structural changes, therefore, the aim of the article is to conduct a comprehensive analysis of transformation processes in the market of tobacco and their alternatives in Ukraine and identify the factors that cause them. The high level of tax burden and the proliferation of alternative products with a potentially lower risk to human health, including heating tobacco products and e-cigarettes, are key factors in the market’s transformation process. Their presence leads to an increase in illicit turnover of tobacco products, which accounts for 6.37% of the market, and the gradual replacement of cigarettes with alternative products, which account for 12.95%. The presence on the market of products that are not taxed or taxed at lower rates is one of the reasons for the reduction of excise duty revenues. According to the results of 2019, the planned indicators of revenues were not met by 23.5%. Other reasons for non-fulfillment of excise duty revenues include: declining dynamics of the tobacco products market; reduction in the number of smokers; reorientation of «cheap whites» cigarette flows from Ukraine to neighboring countries; tax avoidance. Prospects for further research are identified, namely the need to develop measures for state regulation and optimization of excise duty taxation of tobacco products and their alternatives, taking into account the risks to public health and increasing demand of illegal products.

Role of Credit Rating in determining Capital structure: Evidence from Non-Financial sector of Pakistan

2020 ◽  
Vol 38 (3) ◽  
Author(s):  
Shoaib Ali ◽  
Imran Yousaf ◽  
Muhammad Naveed
Keyword(s):  
Capital Structure ◽  
Credit Rating ◽  
Least Square ◽  
Annual Data ◽  
Leverage Ratio ◽  
Financial Decisions ◽  
Financial Firms ◽  
High Level ◽  
The Impact ◽  
The Capital Structure

This paper aims to examine the impact of external credit ratings on the financial decisions of the firms in Pakistan.  This study uses the annual data of 70 non-financial firms for the period 2012-2018. It uses ordinary least square (OLS) to estimate the impact of credit rating on capital structure. The results show that rated firm has a high level of leverage. Moreover, Profitability and tanagability are also found to be a significantly negative determinant of the capital structure, whereas, size of the firm has a significant positive relationship with the capital structure of the firm.  Besides, there exists a non-linear relationship between the credit rating and the capital structure. The rated firms have higher leverage as compared to the non-rated firms. The high and low rated firms have a low level of leverage, while mid rated firms have a higher leverage ratio. The finding of the study have practical implications for the manager; they can have easier access to the financial market by just having a credit rating no matter high or low. Policymakers must stress upon the rating agencies to keep improving themselves as their rating severs as the measure to judge the creditworthiness of the firm by both the investors and management as well.

Воздействиеультразвуковогополянадинамическуювязкостьводы

2019 ◽  
pp. 27-29
Author(s):  
P. Vikulin ◽  
K. Khlopov ◽  
M. Cherkashin
Keyword(s):  
Dynamic Viscosity ◽  
Experimental Studies ◽  
Ultrasonic Field ◽  
Maximum Effect ◽  
Ultrasonic Frequency ◽  
Ultrasonic Vibrations ◽  
Wastewater Disposal ◽  
Laboratory Setup ◽  
Sonic Treatment ◽  
The Impact

Enhancing water purification processes is provided by various methods including physical ones, in particular, exposure to ultrasonic vibrations. The change in the dynamic viscosity of water affects the rate of deposition of particles in the aquatic environment which can be used in natural and wastewater treatment. At the Department Water Supply and Wastewater Disposal of the National Research Moscow State University of Civil Engineering experimental studies were conducted under laboratory conditions to study the effect of ultrasound on the change in the dynamic viscosity of water. A laboratory setup has been designed consisting of an ultrasonic frequency generator of the relative intensity, a transducer (concentrator) that transmits ultrasonic vibrations to the source water, and sonic treatment tanks. Experimental studies on the impact of the ultrasonic field in the cavitation mode on the dynamic viscosity of the aqueous medium were carried out the exposure time was obtained to achieve the maximum effect.Интенсификация процессов очистки воды осуществляется с помощью различных методов, в том числе и физических, в частности воздействием ультразвуковых колебаний. Изменение динамической вязкости воды влияет на скорость осаждения частиц в водной среде, что может быть использовано в процессах очистки природных и сточных вод. На кафедре Водоснабжение и водоотведение Национального исследовательского Московского государственного строительного университета в лабораторных условиях проведены экспериментальные исследования по изучению влияния ультразвука на изменение динамической вязкости воды. Разработана схема лабораторной установки, состоящая из генератора ультразвуковых частот с соответствующей интенсивностью, преобразователя (концентратора), передающего ультразвуковые колебания в исходную воду, и емкости для озвучивания. Выполнены экспериментальные исследования по влиянию ультразвукового поля в режиме кавитации на динамическую вязкость водной среды, получено время экспозиции для достижения максимального эффекта.

IDENTIFICATION AND ASSESSMENT OF RISK FACTORS ROLE IN MYOCARDIAL INFARCTION DEVELOPMENT

2019 ◽  
Vol 72 (5) ◽  
pp. 779-783
Author(s):  
Victor A. Ognev ◽  
Anna A. Podpriadova ◽  
Anna V. Lisova
Keyword(s):  
Risk Factors ◽  
Myocardial Infarction ◽  
Cardiovascular Disease ◽  
Cardiovascular System ◽  
Control Group ◽  
Biological Factors ◽  
Prevention And Treatment ◽  
High Level ◽  
Social Importance ◽  
The Impact

Introduction:The high level of morbidity and mortality from cardiovascular disease is largely due toinsufficient influence on the main risk factors that contribute to the development of myocardial infarction.Therefore, a detailed study and assessment of risk factors is among the most important problems of medical and social importance. The aim: To study and evaluate the impact of biological, social and hygienic, social and economic, psychological, natural and climatic risk factors on the development of myocardial infarction. Materials and methods: A sociological survey was conducted in 500 people aged 34 to 85. They were divided into two groups. The main group consisted of 310 patients with myocardial infarction. The control group consisted of 190 practically healthy people, identical by age, gender and other parameters, without diseases of the cardiovascular system. Results: It was defined that 30 factors have a significant impact on the development of myocardial infarction.Data analysis revealed that the leading risk factors for myocardial infarction were biological and socio-hygienic. The main biological factors were: hypertension and hypercholesterolemia. The man socio-hygienic factor was smoking. Conclusions: Identification of risk factors provides new opportunities for the development of more effective approaches for the prevention and treatment of myocardial infarction.

Family Influences on Youth Offending

2018 ◽  
pp. 377-403
Author(s):  
Abigail A. Fagan ◽  
Kristen M. Benedini
Keyword(s):  
Life Course ◽  
Family Environment ◽  
Parenting Practices ◽  
Experimental Studies ◽  
The United States ◽  
Parental Violence ◽  
Youth Delinquency ◽  
The Impact ◽  
Children’S Exposure

This chapter reviews the degree to which empirical evidence demonstrates that families influence youth delinquency. Because they are most likely to be emphasized in life-course theories, this chapter focuses on parenting practices such as parental warmth and involvement, supervision and discipline of children, and child maltreatment. It also summarizes literature examining the role of children's exposure to parental violence, family criminality, and young (teenage) parents in affecting delinquency. Because life-course theories are ideally tested using longitudinal data, which allow examination of, in this case, the impact of parenting practices on children's subsequent behaviors, this chapter focuses on evidence generated from prospective studies conducted in the United States and other countries. It also discusses findings from experimental studies designed to reduce youth substance use and delinquency by improving the family environment.

scholarly journals Methionine Diet Evoked Hyperhomocysteinemia Causes Hippocampal Alterations, Metabolomics Plasma Changes and Behavioral Pattern in Wild Type Rats

2021 ◽  
Vol 22 (9) ◽  
pp. 4961
Author(s):  
Maria Kovalska ◽  
Eva Baranovicova ◽  
Dagmar Kalenska ◽  
Anna Tomascova ◽  
Marian Adamkov ◽  
...  
Keyword(s):  
Morphological Changes ◽  
Brain Area ◽  
Critical Role ◽  
Cerebrovascular Diseases ◽  
Behavioral Pattern ◽  
Cell Physiology ◽  
Male Wistar Rats ◽  
High Level ◽  
Hippocampal Alterations ◽  
The Impact

L-methionine, an essential amino acid, plays a critical role in cell physiology. High intake and/or dysregulation in methionine (Met) metabolism results in accumulation of its intermediate(s) or breakdown products in plasma, including homocysteine (Hcy). High level of Hcy in plasma, hyperhomocysteinemia (hHcy), is considered to be an independent risk factor for cerebrovascular diseases, stroke and dementias. To evoke a mild hHcy in adult male Wistar rats we used an enriched Met diet at a dose of 2 g/kg of animal weight/day in duration of 4 weeks. The study contributes to the exploration of the impact of Met enriched diet inducing mild hHcy on nervous tissue by detecting the histo-morphological, metabolomic and behavioural alterations. We found an altered plasma metabolomic profile, modified spatial and learning memory acquisition as well as remarkable histo-morphological changes such as a decrease in neurons’ vitality, alterations in the morphology of neurons in the selective vulnerable hippocampal CA 1 area of animals treated with Met enriched diet. Results of these approaches suggest that the mild hHcy alters plasma metabolome and behavioural and histo-morphological patterns in rats, likely due to the potential Met induced changes in “methylation index” of hippocampal brain area, which eventually aggravates the noxious effect of high methionine intake.

scholarly journals Anthropomorphic Strategies Promote Wildlife Conservation through Empathy: The Moderation Role of the Public Epidemic Situation

2021 ◽  
Vol 18 (7) ◽  
pp. 3565
Author(s):  
Dan Yue ◽  
Zepeng Tong ◽  
Jianchi Tian ◽  
Yang Li ◽  
Linxiu Zhang ◽  
...  
Keyword(s):  
College Students ◽  
Behavioral Intention ◽  
Wildlife Conservation ◽  
Negative Emotion ◽  
Public Awareness ◽  
Negative Emotions ◽  
Experimental Studies ◽  
Wildlife Trade ◽  
Illegal Wildlife Trade ◽  
The Impact

The global illegal wildlife trade directly threatens biodiversity and leads to disease outbreaks and epidemics. In order to avoid the loss of endangered species and ensure public health security, it is necessary to intervene in illegal wildlife trade and promote public awareness of the need for wildlife conservation. Anthropomorphism is a basic and common psychological process in humans that plays a crucial role in determining how a person interacts with other non-human agents. Previous research indicates that anthropomorphizing nature entities through metaphors could increase individual behavioral intention of wildlife conservation. However, relatively little is known about the mechanism by which anthropomorphism influences behavioral intention and whether social context affects the effect of anthropomorphism. This research investigated the impact of negative emotions associated with a pandemic situation on the effectiveness of anthropomorphic strategies for wildlife conservation across two experimental studies. Experiment 1 recruited 245 college students online and asked them to read a combination of texts and pictures as anthropomorphic materials. The results indicated that anthropomorphic materials could increase participants’ empathy and decrease their wildlife product consumption intention. Experiment 2 recruited 140 college students online and they were required to read the same materials as experiment 1 after watching a video related to epidemics. The results showed that the effect of wildlife anthropomorphization vanished if participants’ negative emotion was aroused by the video. The present research provides experimental evidence that anthropomorphic strategies would be useful for boosting public support for wildlife conservation. However, policymakers and conservation organizations must be careful about the negative effects of the pandemic context, as the negative emotions produced by it seems to weaken the effectiveness of anthropomorphic strategies.

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