2020 Max Jacob Memorial Award (P. C. Wayner, Jr.) Review: Change-of-Phase in an Extended Meniscus

2021 ◽  
Author(s):  
Peter C. Wayner Jr. ◽  
Joel L. Plawsky
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Space Station ◽  
Intermolecular Forces ◽  
Film Boiling ◽  
International Space ◽  
The Past ◽  
The Subject ◽  
Memorial Award

Abstract The extended meniscus and the intermolecular and capillary forces that govern its behavior and connection to change of phase heat transfer have been the subject of an increasing body of research over the past 50 years. We have been fortunate to be at the forefront of this effort starting from the development of a capillary feeder, in Earth's gravity, to stabilize film boiling to running a series of transparent heat pipe experiments aboard the International Space Station hoping to better understand the role of intermolecular forces in microgravity. The use of ellipsometry and interferometry to highlight the location and state of the vapor-liquid interface have been key to these studies and have helped to uncover many new, interesting, and sometimes unexpected, phenomena associated with fluid flow and change-of-phase heat transfer.

Space Medicine Propelling Earth-Based Medicine for the Advantage of Human on Earth – A Vision Beyond 2020

2020 ◽  
Author(s):  
Kris See
Keyword(s):  
International Space Station ◽  
Good Condition ◽  
Space Station ◽  
Gear Up ◽  
Space Medicine ◽  
International Space ◽  
The Future ◽  
Based Medicine

What will be the future of medicine a decade from now? What difficulties related with preventing, detecting, and treating diseases will have been unraveled? How will space medicine make an impact?. Today as compared to previously, it is the role of space medicine to gear up astronauts sufficiently for their missions and also to maintain their health in good condition. Moreover, the exclusive and new environmental surroundings existing in space continuously propose prospects to validate theories and assumptions established by earth-based medicine and recognize likely mistakes and disparities, as we have been observing approximately more than a decade with outcomes for example, from the International Space Station.

scholarly journals Shopping Centres, Cycling Accessibility and Planning—The Case of Nova Lund in Sweden

Urban Science ◽  
2020 ◽  
Vol 4 (4) ◽  
pp. 70
Author(s):  
Till Koglin ◽  
Lucas Glasare
Keyword(s):  
Conflicts Of Interest ◽  
Current Situation ◽  
Decision Makers ◽  
Power Structures ◽  
Literature Study ◽  
Shopping Centre ◽  
The Past ◽  
Whole Process ◽  
The Subject

This paper evaluates the history and cycling accessibility of Nova, a shopping centre established in Lund, Sweden, in 2002. The current situation was also analysed through observation and a literature review. Moreover, the study conducted a closer analysis of the history and role of the municipality based on further literature study and interviews with officials. The conclusion of the analysis indicates poor and unsafe bikeways caused by conflicts of interest between politicians, officials, landowners and the general public. It also depicts a situation in which the municipality’s master plan has been ignored, and, in contrast to the local goals, cycling accessibility at Nova has seen no significant improvement since the shopping centre was first established. The reasons for this, arguably, are a relatively low budget for bikeway improvements in the municipality, as well as a situation in which decision-makers have stopped approaching the subject, as a result of the long and often boisterous conflicts it has created in the past. Lastly, it must be noted that it is easy to regard the whole process of Nova, from its establishment to the current situation, as being symptomatic of the power structures between drivers and cyclists that still affect decision-makers at all levels.

scholarly journals Tocopherols and Tocotrienols—Bioactive Dietary Compounds; What Is Certain, What Is Doubt?

2021 ◽  
Vol 22 (12) ◽  
pp. 6222
Author(s):  
Kacper Szewczyk ◽  
Aleksandra Chojnacka ◽  
Magdalena Górnicka
Keyword(s):  
Vitamin E ◽  
Metabolic Disorders ◽  
Tissue Concentration ◽  
Biological Properties ◽  
Biological Role ◽  
Future Research ◽  
The Past ◽  
The Subject ◽  
The Relationship

Tocopherols and tocotrienols are natural compounds of plant origin, available in the nature. They are supplied in various amounts in a diet, mainly from vegetable oils, some oilseeds, and nuts. The main forms in the diet are α- and γ-tocopherol, due to the highest content in food products. Nevertheless, α-tocopherol is the main form of vitamin E with the highest tissue concentration. The α- forms of both tocopherols and tocotrienols are considered as the most metabolically active. Currently, research results indicate also a greater antioxidant potential of tocotrienols than tocopherols. Moreover, the biological role of vitamin E metabolites have received increasing interest. The aim of this review is to update the knowledge of tocopherol and tocotrienol bioactivity, with a particular focus on their bioavailability, distribution, and metabolism determinants in humans. Almost one hundred years after the start of research on α-tocopherol, its biological properties are still under investigation. For several decades, researchers’ interest in the biological importance of other forms of vitamin E has also been growing. Some of the functions, for instance the antioxidant functions of α- and γ-tocopherols, have been confirmed in humans, while others, such as the relationship with metabolic disorders, are still under investigation. Some studies, which analyzed the biological role and mechanisms of tocopherols and tocotrienols over the past few years described new and even unexpected cellular and molecular properties that will be the subject of future research.

A corpus-based investigation of techno-optimism and propositional certainty in the National Intelligence Council’s ‘Future Global Trends Reports’ (2010–2035)

2017 ◽  
Vol 12 (1) ◽  
pp. 39-57
Author(s):  
Jamie McKeown
Keyword(s):  
Global Trends ◽  
Future Role ◽  
Ideological Bias ◽  
The Past ◽  
The Us ◽  
The Future ◽  
The Subject ◽  
Global Peace ◽  
Discursive Representations

This article reports the findings from a study of discursive representations of the future role of technology in the work of the US National Intelligence Council (NIC). Specifically, it investigates the interplay of ‘techno-optimism’ (a form of ideological bias) and propositional certainty in the NIC’s ‘Future Global Trends Reports’. In doing so, it answers the following questions: To what extent was techno-optimism present in the discourse? What level of propositional certainty was expressed in the discourse? How did the discourse deal with the inherent uncertainty of the future? Overall, the discourse was pronouncedly techno-optimist in its stance towards the future role of technology: high-technological solutions were portrayed as solving a host of problems, despite the readily available presence of low-technology or no-technology solutions. In all, 75.1% of the representations were presented as future categorical certainties, meaning the future was predominantly presented as a known and closed inevitability. The discourse dealt with the inherent uncertainty of the subject matter, that is, the future, by projecting the past and present into the future. This was particularly the case in relation to the idea of technological military dominance as a guarantee of global peace, and the role of technology as an inevitable force free from societal censorship.

New Agendas for Special Education Policy: What the National Reports Haven't Said

1987 ◽  
Vol 53 (4) ◽  
pp. 295-299 ◽  
Author(s):  
Marleen Pugach ◽  
Mara Sapon-Shevin
Keyword(s):  
Special Education ◽  
Education Policy ◽  
Educational Reform ◽  
Special Focus ◽  
Special Education Policy ◽  
The Past ◽  
The Subject ◽  
The Impact ◽  
The Relationship

The calls for educational reform that have dominated the professional and lay literature for the past few years have been decidedly silent in discussing the role of special education either as a contributor or a solution to the problems being raised. As an introduction to this “Special Focus” on the relationship between general educational reform and special education, this article summarizes some of the more prominent reports with regard to their treatment (and nontreatment) of special education. The impact of proposed reforms for the conceptualization and operation of special education is the subject of the five articles that follow.

scholarly journals Influence of Vibration on Diffusion in Liquid Mixtures On-Board the International Space Station

2021 ◽  
Author(s):  
Aram Parsa
Keyword(s):  
Heat Transfer ◽  
Numerical Analysis ◽  
Physical Properties ◽  
International Space Station ◽  
Diffusion Coefficients ◽  
Space Station ◽  
Flow Patterns ◽  
Transport Processes ◽  
International Space ◽  
Different Levels

Experiments on-board the International Space Station experience a convective flow due to the oscillatory g-jitters induced by several sources such as crew activities, mechanical systems, thrusters firing, spacecraft docking, etc. Although g-jitter seems to have a major impact on diffusion-related experiments in Space, very few experimental studies have addressed this topic. This study examined the effect of oscillatory g-jitters on transport processes (fluid flow, heat transfer and mass transfer). Cubic rigid cells filled with water and isopropanol at different concentrations were subjected to thermal gradients and forced vibrations. The cells were exposed to different levels of vibration in terms of frequency and amplitude, which were applied perpendicular to the temperature gradient. The full transient Navier Stokes equations coupled with the mass and heat transfer formulas were solved numerically using the control volume technique. The physical properties of the fluid mixture such as the density were determined using two different models. The effect of different levels of vibration on the flow was analysed and the results were compared in a benchmark study with other scientific groups. The effect of the diffusion coefficients variation and other physical properties on the temperature and concentration distribution was compared to those results obtained with constant diffusion coefficients. Results show that use of variable physical properties in the modelling produces different flow patterns and component concentration. By examining different flow patterns, it was found that the effect of using variable coefficients is much more significant in the cases with high Rayleigh vibration that result in strong flow when compared with numerical analysis using constant variables. The numerical analysis was also performed for the actual experiment on board the International Space Station. The same trend was seen for both the numerical and experimental results. However, the separation of components was higher in the experiment in comparison with the numerical analysis. This was discussed in detail for various scenarios in terms of the applied frequency and amplitude. Recommendations are made according to the findings from this study for the improvement of accuracy in the numerical and experimental analyses of future diffusion experiments in Space.

scholarly journals Influence of Vibration on Diffusion in Liquid Mixtures On-Board the International Space Station

2021 ◽  
Author(s):  
Aram Parsa
Keyword(s):  
Heat Transfer ◽  
Numerical Analysis ◽  
Physical Properties ◽  
International Space Station ◽  
Diffusion Coefficients ◽  
Space Station ◽  
Flow Patterns ◽  
Transport Processes ◽  
International Space ◽  
Different Levels

Experiments on-board the International Space Station experience a convective flow due to the oscillatory g-jitters induced by several sources such as crew activities, mechanical systems, thrusters firing, spacecraft docking, etc. Although g-jitter seems to have a major impact on diffusion-related experiments in Space, very few experimental studies have addressed this topic. This study examined the effect of oscillatory g-jitters on transport processes (fluid flow, heat transfer and mass transfer). Cubic rigid cells filled with water and isopropanol at different concentrations were subjected to thermal gradients and forced vibrations. The cells were exposed to different levels of vibration in terms of frequency and amplitude, which were applied perpendicular to the temperature gradient. The full transient Navier Stokes equations coupled with the mass and heat transfer formulas were solved numerically using the control volume technique. The physical properties of the fluid mixture such as the density were determined using two different models. The effect of different levels of vibration on the flow was analysed and the results were compared in a benchmark study with other scientific groups. The effect of the diffusion coefficients variation and other physical properties on the temperature and concentration distribution was compared to those results obtained with constant diffusion coefficients. Results show that use of variable physical properties in the modelling produces different flow patterns and component concentration. By examining different flow patterns, it was found that the effect of using variable coefficients is much more significant in the cases with high Rayleigh vibration that result in strong flow when compared with numerical analysis using constant variables. The numerical analysis was also performed for the actual experiment on board the International Space Station. The same trend was seen for both the numerical and experimental results. However, the separation of components was higher in the experiment in comparison with the numerical analysis. This was discussed in detail for various scenarios in terms of the applied frequency and amplitude. Recommendations are made according to the findings from this study for the improvement of accuracy in the numerical and experimental analyses of future diffusion experiments in Space.

scholarly journals Adad [Antonyms] and Its Impact on the Exegesis of Al-Samin in His Books (Al-Durr) And (Al-’Umda)

2021 ◽  
Vol 17 ◽  
pp. 144-158
Author(s):  
Dr. Ayman Ibrahim Yusuf Rayan
Keyword(s):  
Close Connection ◽  
Great Contribution ◽  
Intended Meaning ◽  
The Past ◽  
Linguistic Research ◽  
Holy Quran ◽  
The Holy Quran ◽  
The Subject

This research tackles the subject of the indication of antonyms and its impact on the exegesis of al-Samin in both his books “al-Durr al-Masun” (Preserved Pearls) and “‘Umdat al-Hufaz” (Reliance of the memorize-rs). In this research, I have combined between the language and tafsir (exegesis) and clarified the efforts exerted by al-Samin in serving the interpretation of the Quran. Moreover, I have introduced his great contribution to linguistic research and compiled the conclusions he has reached in both his books (al-Durr) and (al-’Umda) on antonyms. I have organized his ideas, studied his tangible effects in his exegesis of the holy Quran in addition to methodologically establishing the role of the language being one of the tools in the past and contemporary exegesis of the holy  Quran and clarified its multiple indications and various manners. I was also keen in highlighting the importance of the indication of antonyms and the extent of its impact on interpreting the noble Quran. Moreover, I have studied the points of contention among the scholars and exegists on the meaning of the Quranic statement and clarified the importance of the Quranic context in determining the exact meaning of the vocabularies and structures. Furthermore, I have highlighted the close connection between the developed indication of words and the intended meaning in the Quranic verse.

scholarly journals Design of a Small-Scale Experimental Model of the International Space Station Crew Quarters for a PIV Flow Field Study

2019 ◽  
Vol 111 ◽  
pp. 01045
Author(s):  
Matei-Razvan Georgescu ◽  
Ilinca Nastase ◽  
Amina Meslem ◽  
Mihnea Sandu ◽  
Florin Bode
Keyword(s):  
International Space Station ◽  
Numerical Models ◽  
Space Station ◽  
Scale Model ◽  
Microgravity Environment ◽  
Small Scale ◽  
Piv Measurements ◽  
International Space ◽  
The Subject ◽  
Small Scale Model

An attempt at improving the ventilation solution for the crew quarters aboard the International Space Station requires a thorough understanding of the flow dynamics in a microgravity environment. An experimental study is required in order to validate the numerical models. As part of this process, a small-scale model was proposed for a detailed study of the velocity field. PIV measurements in water offer high quality results and were chosen for the subject. Following certain similitude criteria, an equivalence can be found between the results of these measurements and the real ventilation scenario. This paper describes the development process of this small-scale model as well as its performance in the initial test runs. Details regarding the advantages and weaknesses of this first model are the core of the paper, with the intention of aiding researchers in their design of similar models. The conclusion presents future steps and proposed improvements to the model.

Unsteady theory of heat transfer and fluid flow during instantaneous transition to film boiling

2020 ◽  
Vol 153 ◽  
pp. 106345
Author(s):  
А.A. Avramenko ◽  
I.V. Shevchuk ◽  
N.P. Dmitrenko ◽  
Yu.Yu. Kovetska ◽  
A.I. Tyrinov
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Film Boiling
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