scholarly journals Insulating Materials at Very Low Temperatures: A Short Review

2020 ◽  
Vol 10 (3) ◽  
pp. 5590-5595 ◽  
Author(s):  
P. Malelis ◽  
M. Danikas

In this paper, a short review is given on insulating materials at very low temperatures. Various insulating materials are investigated in terms of phenomena such as partial discharges. Some of the factors affecting the behavior of the insulating materials at very low temperatures, such as the quality of electrode surface, the stressed insulation volume and the existing bubbles, are also reported and commented upon. Proposals for future research are also discussed.

Processes ◽  
2020 ◽  
Vol 8 (12) ◽  
pp. 1572
Author(s):  
Ali Alsayegh ◽  
Naser Ali

Coolant is one of the main factors affecting the overall thermal performance of the intercooler for the gas turbine intercooled cycle. The thermal conductivity of conventional coolants, such as water, is relatively low when compared to solid conducting materials, and therefore can hinder the progress towards achieving a compact and highly effective intercooler. Nanofluids are advanced types of working fluids that contain dispersed nanoparticles in conventional basefluids, and as such possess superior thermal conductivity compared to their counterparts. In this paper, a short review on the effect of different nanofluids on the thermal performance of gas turbines intercoolers is presented for the first time. Firstly, this work reviews the different designs of intercoolers used in gas turbines intercooled cycles. Then, it explains the different types of nanofluids and their fabrication processes. The effective parameters, such as physical stability, thermal conductivity, and viscosity are also highlighted and discussed. Furthermore, the level of enhancement in the performance of intercoolers utilizing nanofluids is demonstrated and evaluated. Lastly, the current challenges and future research directions in this field are provided.


2019 ◽  
Vol 9 (5) ◽  
pp. 4659-4666 ◽  
Author(s):  
M. Danikas ◽  
S. Morsalin

Partial discharges in cavities are one of the main reasons of breakdown of insulating materials and insulating systems in general. The present paper aims at commenting some aspects of the relation between partial discharges and insulation damage. Some basic models explaining the workings and impacts of discharges in cavities are discussed. Discussions about the possibility of damage in the presence of multiple cavities as well as of the risks of minute discharges and/or charging phenomena below the so-called inception voltage are conducted. It is remarked that the question of the relationship between discharge parameters and insulation damage is still an important one, especially for composite insulating systems.


2020 ◽  
Vol 71 ◽  
pp. 59-76
Author(s):  
Ali SIMSEK ◽  
Fahme DABAJ ◽  
Eylem SIMSEK

The use of Facebook in everyday life has become widespread all around the world regardless of countries and cultures. The largest group of Facebook users consists of young people, particularly university students. This study investigated the attitudes of university students toward Facebook, their major reasons for using this social media application in everyday life, and the factors affecting the types of desired relationships with Facebook friends. A survey consisting of 63 items about demographics of participants and their preferences for the use of Facebook was administered to collect data. The sample of the study included 924 undergraduate students from a large public university in North Cyprus. A number of descriptive and inferential statistical techniques were employed to analyze data in relation to the research questions. Results suggested that the students generally had positive attitudes toward Facebook, although there were certain differences in terms of demographics. The primary reason for using Facebook was interpersonal communications with close friends. The most powerful factor affecting the types of relationships in Facebook was perceived quality of communication and/or socialization. Along with the other findings, implications of the results for future research were discussed.


Author(s):  
Amulya Gurtu ◽  
Cory Searcy ◽  
Mohamad Y. Jaber

This chapter discusses sustainability in supply chains. It starts with a review of the concepts of sustainability and supply chain management; provides a discussion on the globalization of supply chains, its influence on sustainability, benefits of sustainable supply chains followed by the factors affecting the sustainability of supply chains, challenges in integrating sustainability into supply chains and managerial implications. It discusses the influence of supply chains on the triple bottom line. Examples of major factors affecting environmental and social sustainability include travel distances, modes of transportation, vessels used, frequency of trips, packaging materials, efficiencies of manufacturing processes, efficiencies in power generation/distribution, treatments given to polluted air/water generated during various processing from industries, expected product lifetime, manufactured quality of items, management of items failed during warranty or transportation, and the management of disposal of items, among others. The chapter concludes with a future research agenda.


1997 ◽  
Vol 44 (3) ◽  
pp. 167-181 ◽  
Author(s):  
Hyunsook Yoon

Among the most prevalent disabling diseases of old age, stroke is the leading chronic condition in Korea. The physical and psychosocial complications of a stroke can result in serious limitations on all aspects of one's life that affect overall quality of life. This study examines the relative importance of and interactions among factors which affect the quality of life of 119 stroke patients aged sixty-five and older in Korea. The model uses family support, personality (specifically hardiness), economic status, and physical functioning as independent variables, and quality of life as a dependent variable. The results of this study suggest that physical functioning and physical care by the family are important factors influencing quality of life of the aged stroke patients. Hardy personality is negatively associated with financial support and physical care by the family. These findings have several implications for policy development, clinical practice, and future research in this area.


2001 ◽  
Vol 41 (7) ◽  
pp. 879 ◽  
Author(s):  
D. M. Ferguson ◽  
H. L. Bruce ◽  
J. M. Thompson ◽  
A. F. Egan ◽  
D. Perry ◽  
...  

The potential eating quality of beef is set by the intrinsic structural and compositional characteristics of muscle. However, the extrinsic factors that prevail during the production of the animal, slaughter and processing of its carcass and finally, cooking can produce changes in these structural and compositional characteristics that ultimately manifest as large variations in beef palatability. The conditions that apply in the 24–48 h immediately before and after slaughter are recognised as having the largest influence on beef palatability. This review specifically examines the critical pre- and post-slaughter factors and discusses their putative effects on biochemical and physical changes in muscle and the consequences to beef palatability. Areas for future research within this domain are also discussed.


2010 ◽  
Vol 437 ◽  
pp. 584-588
Author(s):  
Romeo Cristian Ciobanu ◽  
Cristina Schreiner

The broadband Partial Discharge (PD) measurement technique may be considered more accurate than a simple breakdown test and admitted as a complementary method for characterizing the quality of porous/fibrous and composite insulating materials. It should be taken into account especially at higher frequencies, when the risk of breakdown occurrence becomes greater in time, due to the local thermal aspects.


2015 ◽  
Vol 117 (7) ◽  
pp. 1903-1920 ◽  
Author(s):  
Veljko Marinkovic ◽  
Vladimir Senic ◽  
Predrag Mimovic

Purpose – With the expansion of dining out, visiting ethnic restaurants is becoming one of dominant trends worldwide. Given the fact that ethnic restaurants involve a number of peculiar elements that are not present when visiting regular “local” restaurants, the purpose of this paper is to identify the key determinants of choosing a particular ethnic-themed restaurant, as well as factors that have an impact on an ethnic restaurant’s perceived image. Design/methodology/approach – Research was done by conducting two separate studies. The first study identified factors that were generally the most significant to respondents when making a choice of an ethnic restaurant in which to dine. For the second study, a new sample of respondents – consisting of those who had just visited such an establishment – was used in order to determine which factors have the most significant impact on creating an image of ethnic restaurants. The research was therefore directed toward those restaurants where the customers can experience a unique atmosphere and ambiance that are synonymous within a given culture. Findings – The results obtained from the first study show that quality of food and price are the two most significant factors that determine which restaurant will be visited. On the other hand, the interior and exterior ranked as the two least important factors. In addition, the second study revealed that following the visit, the strongest impact on the restaurant’s image was its interior. Following interior, service quality surfaced as the most important antecedent of perceived image, while the impacts of price and exterior were weaker, but still statistically significant. Research limitations/implications – The study itself was done in two stages. In the first stage the analytical hierarchical process (AHP) model was used for ranking factors significant for choosing an ethnic restaurant, while in the second stage, structural equation modeling (SEM) model was used to identify triggers of perceived image after a visit to an ethnic restaurant. Future research should utilize both models to determine antecedents of the variables used. Apart from this, it is recommended to employ new variables that further explore the uniqueness of the ethnic restaurants. Originality/value – One of the main contributions of this work is related to combining of the AHP and SEM models, with the objective of completing a comparative results analysis, identifying in the process the positive aspects of both models and building a foundation for their coordination in terms of future use. This is significant, given that only a few prior studies have used such synergy.


2021 ◽  
Vol 55 (2) ◽  
Author(s):  
Elzbieta T. Kazmierczak

This article presents an empirical investigation into interpreters’ decision-making criteria, personality characteristics, and emotion-laden experiences as factors affecting interpretation of images that were created for diagnostic assessment. Specifically, it seeks to examine (1) heuristic strategies as interpretive tools, which are both cognitive and experience-based, (2) the relationship between the decision criteria and accuracy of the judgments, and (3) the relationship between interpreters’ experiences of abuse as victims and the judgments about the meaning of images. The study used a sample of 196 self-representational drawings created by college students and 60 independent interpreters who were asked to identify drawings that were created by individuals who experienced interpersonal abuse. This study identified six visual heuristics that were reported independently by 60 percent of the interpreters and were associated with marginally higher accuracy of the interpretive judgments. Thirty-eight percent of participants reported making judgments about the meaning of drawings based on direct or secondhand experiences with interpersonal abuse. The study found that the trauma of interpersonal abuse can profoundly bias interpretive judgments. This result has been particularly robust among female interpreters. Women who self-identified as survivors of abuse saw indicators of abuse up to 90 percent of the time, whereas male interpreters who have been abused saw indicators of abuse up to 65 percent of the time, whether or not those purported indicators were correct. Implications of the findings for design are discussed. An overarching goal of this article is to address interpretation of images as a decision process. The study situated the factors affecting interpretation of images within the framework of the naturalistic/ ecological psychology (Brunswik, 1952, 1955) and the fast and frugal heuristic model of decision-making (Gigerenzer, 2007) vis-à-vis a model of conscious and nonconscious information processing. This study also recognized that certain personality characteristics and emotion-laden experiences can influence the quality of interpretive judgments. The frameworks, methods, and findings from psychology have been used with an intent to inform future research and practice of image construction and interpretation in visual studies and design. One limitation of this study is that it relied on participants’ introspection and reflection on the decision process. There is a risk, then, that interpreters’ explanations of how they arrived with judgments were translations rather than representations of the decision process. Even though this study has not cracked the black box of meaning-making inside the mind, it offers an analytical framework for studies of visual interpretation as a decision process that combines cognitive, personality, and experiential factors as influencing the quality of interpretations. The article translates the findings of the study into practical guidelines for applications in visual communication design and human-centered design research and practice.


2018 ◽  
Vol 8 (5) ◽  
pp. 3300-3309 ◽  
Author(s):  
M. Danikas

Nanofluids seem to gradualy become an alternative to traditional insulating liquids, such as transformer oil. In this paper, a short review of experimental results as well as of possible breakdown mechanisms and of some of the factors affecting the breakdown strength of the said fluids is conducted. Most of the reports suggest that the addition of nanoparticles in insulating liquids improves the breakdown strength. However, some reports that contradict the above are also to be found. In view of this, an outline of future research is discussed. This review does not encompass all possible effects, parameters and factors affecting nanofluids but it is solely concerned with breakdown strength.


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