The Proöxygenic Role of Iron in the Oxidizability of Rubber

1934 ◽  
Vol 7 (2) ◽  
pp. 213-233 ◽  
Author(s):  
Charles Dufraisse ◽  
Roger Vieillefosse
Keyword(s):  
Current Practice ◽  
Manufacturing Processes ◽  
Iron Compounds ◽  
Simple Manner ◽  
Rubber Mixture ◽  
The Past ◽  
Harmful Effects

Abstract The influence of iron on the oxidizability of rubber, though not as a matter of fact neglected in the past, has perhaps not received sufficient attention. However, the various ways in which this metal and its derivatives have caused contamination are certainly too obvious to imagine that they have passed unobserved. As is known, traces of iron can be detected in latex at the time it is tapped, and regardless of the method of treatment which it undergoes later, the rubber has an opportunity at every step in its preparation to become further contaminated with iron. Milling, calendering, and molding are carried out with iron equipment, and the ingredients used in rubber compounding may contain more or lees iron, at least as impurities, even when they are not primarily iron compounds, as is the case of certain pigments. In short, manufacturing processes, contamination by iron from ingredients, adventious causes such as iron containers for latex, dust and various other causes which need not be enumerated, all contribute to the presence of iron in rubber. Certainly then iron cannot be a very dangerous element under ordinary conditions, for otherwise its harmful effects would have been recognized long ago, and would have led to the avoidance of iron in practice, as has happened in the case of copper. Nevertheless experiments of the authors to determine why vulcanization increases the oxidizability of rubber have led to the suspicion that iron may be harmful, and a desire to ascertain the role it plays in deterioration prompted the authors to carry out the experiments which are described in the present paper. The object of the work was thus limited, and it aimed not to settle the problem of the influence of iron on rubber, but rather to investigate in a simple manner in what way iron gets into a rubber mixture, in what form it exists, and what are its harmful effects. Incidental to this, some of the observations may perhaps be of some value in current practice.

A History of Meta-Regression: Technical, Conceptual, and Practical Developments between 1974 and 2018

2019 ◽  
Author(s):  
Elizabeth Tipton ◽  
James E Pustejovsky ◽  
Hedyeh Ahmadi
Keyword(s):  
Current Practice ◽  
Meta Analysis ◽  
Regression Methods ◽  
The Past ◽  
Open Questions ◽  
History Of ◽  
Meta Regression ◽  
Education Psychology ◽  
Psychology And Medicine

At the beginning of the development of meta-analysis, understanding the role of moderators was given the highest priority, with meta-regression provided as a method for achieving this goal. Yet in current practice, meta-regression is not as commonly used as anticipated. This paper seeks to understand this mismatch by reviewing the history of meta-regression methods over the past 40 years. We divide this time span into four periods and examine three types of methodological developments within each period: technical, conceptual, and practical. Our focus is broad and includes development of methods in the fields of education, psychology, and medicine. We conclude the paper with a discussion of five consensus points, as well as open questions and areas of research for the future.

scholarly journals EDUCATIONAL TECHNOLOGY: THE INFLUENCE OF THEORY

2018 ◽  
Author(s):  
Kim Issroff ◽  
Eileen Scanlon
Keyword(s):  
Educational Technology ◽  
Current Practice ◽  
Learning Technologies ◽  
Learning Technology ◽  
Technology Research ◽  
Group Influence ◽  
The Past ◽  
Artificial Intelligence In Education ◽  
Learning Research

In this paper we explore the role of theories in current practice in educational technology. We review a range of writings from the past 30 years on the nature of learning technology research. We discuss influences on learning technologies from the related fields of Artificial Intelligence in Education (AIED) and Human-Computer Interaction (HCI). We identify two groups of theories which have been used. The first group are related to principled decisions about the design of learning materials. The second group influence the ways in which we frame our research on learning. Research in learning technologies in the future will need to draw on both groups of theories. In this paper, we draw on our own experiences as educational technologists and the purpose of the paper is to encourage other educational technologists to join with us in reflecting on their own use of theories.

On Future Directions in Pathology

1982 ◽  
Vol 40 ◽  
pp. 274-277
Author(s):  
Benjamin F. Trump ◽  
Irene K. Berezesky ◽  
Raymond T. Jones
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Clinical Pathology ◽  
Future Directions ◽  
Diagnostic Pathology ◽  
The Past ◽  
Transmission Electron ◽  
Organ Systems ◽  
The Many

The role of electron microscopy and associated techniques is assured in diagnostic pathology. At the present time, most of the progress has been made on tissues examined by transmission electron microscopy (TEM) and correlated with light microscopy (LM) and by cytochemistry using both plastic and paraffin-embedded materials. As mentioned elsewhere in this symposium, this has revolutionized many fields of pathology including diagnostic, anatomic and clinical pathology. It began with the kidney; however, it has now been extended to most other organ systems and to tumor diagnosis in general. The results of the past few years tend to indicate the future directions and needs of this expanding field. Now, in addition to routine EM, pathologists have access to the many newly developed methods and instruments mentioned below which should aid considerably not only in diagnostic pathology but in investigative pathology as well.

A literature review on firms' internationalisation through e-commerce

2019 ◽  
pp. 121-143
Author(s):  
Riccardo Resciniti ◽  
Federica De Vanna
Keyword(s):  
Systematic Review ◽  
Literature Review ◽  
International Business ◽  
Decision Process ◽  
Foreign Markets ◽  
New Markets ◽  
Integrative Framework ◽  
The Past ◽  
The Relationship

The rise of e-commerce has brought considerable changes to the relationship between firms and consumers, especially within international business. Hence, understanding the use of such means for entering foreign markets has become critical for companies. However, the research on this issue is new and so it is important to evaluate what has been studied in the past. In this study, we conduct a systematic review of e-commerce and internationalisation studies to explicate how firms use e-commerce to enter new markets and to export. The studies are classified by theories and methods used in the literature. Moreover, we draw upon the internationalisation decision process (antecedents-modalities-consequences) to propose an integrative framework for understanding the role of e-commerce in internationalisation

Concealment of Illegally Obtained Assets in Nigeria: Revisiting the Role of the Churches in Money Laundering

2020 ◽  
Vol 28 (1) ◽  
pp. 106-121
Author(s):  
Kato Gogo Kingston
Keyword(s):  
Economic Growth ◽  
Money Laundering ◽  
Financial Crime ◽  
The Past ◽  
Key Drivers ◽  
Nigerian Government

Financial crime in Nigeria – including money laundering – is ravaging Nigeria's economic growth. In the past few years, the Nigerian government has made efforts to tackle money laundering by enacting laws and setting up several agencies to enforce the laws. However, there are substantial loopholes in the regulatory and enforcement regimes. This article seeks to unravel the involvement of the churches as key drivers in money laundering crimes in Nigeria. It concludes that the permissive secrecy which enables churches to conceal the names of their financiers and donors breeds criminality on an unimaginable scale.

Provision of Remedies for Violation of Economic, Social and Cultural Rights: A Comparative Study of the United Nations, Inter-American and African Human Rights Systems

2020 ◽  
Vol 28 (2) ◽  
pp. 298-318
Author(s):  
Roman Girma Teshome
Keyword(s):  
Human Rights ◽  
United Nations ◽  
Comparative Study ◽  
Economic Rights ◽  
Regional Monitoring ◽  
Cultural Rights ◽  
The Past ◽  
The United Nations ◽  
To Receive

The effectiveness of human rights adjudicative procedures partly, if not most importantly, hinges upon the adequacy of the remedies they grant and the implementation of those remedies. This assertion also holds water with regard to the international and regional monitoring bodies established to receive individual complaints related to economic, social and cultural rights (hereinafter ‘ESC rights’ or ‘socio-economic rights’). Remedies can serve two major functions: they are meant, first, to rectify the pecuniary and non-pecuniary damage sustained by the particular victim, and second, to resolve systematic problems existing in the state machinery in order to ensure the non-repetition of the act. Hence, the role of remedies is not confined to correcting the past but also shaping the future by providing reforming measures a state has to undertake. The adequacy of remedies awarded by international and regional human rights bodies is also assessed based on these two benchmarks. The present article examines these issues in relation to individual complaint procedures that deal with the violation of ESC rights, with particular reference to the case laws of the three jurisdictions selected for this work, i.e. the United Nations, Inter-American and African Human Rights Systems.

Receptions of the Past: Commemoration, Racism, Desire

Somatechnics ◽  
2017 ◽  
Vol 7 (2) ◽  
pp. 288-303
Author(s):  
Michael Connors Jackman
Keyword(s):  
Critical Point ◽  
Social Relations ◽  
White Privilege ◽  
Body Politic ◽  
The Body ◽  
Race And Racism ◽  
Lesbian And Gay ◽  
The Past ◽  
History Of

This article investigates the ways in which the work of The Body Politic (TBP), the first major lesbian and gay newspaper in Canada, comes to be commemorated in queer publics and how it figures in the memories of those who were involved in producing the paper. In revisiting a critical point in the history of TBP from 1985 when controversy erupted over race and racism within the editorial collective, this discussion considers the role of memory in the reproduction of whiteness and in the rupture of standard narratives about the past. As the controversy continues to haunt contemporary queer activism in Canada, the productive work of memory must be considered an essential aspect of how, when and for what reasons the work of TBP comes to be commemorated. By revisiting the events of 1985 and by sifting through interviews with individuals who contributed to the work of TBP, this article complicates the narrative of TBP as a bluntly racist endeavour whilst questioning the white privilege and racially-charged demands that undergird its commemoration. The work of producing and preserving queer history is a vital means of challenging the intentional and strategic erasure of queer existence, but those who engage in such efforts must remain attentive to the unequal terrain of social relations within which remembering forms its objects.

Vitamin A: dietologist’s position

2020 ◽  
pp. 49-57
Author(s):  
S. V. Orlova ◽  
E. A. Nikitina ◽  
L. I. Karushina ◽  
Yu. A. Pigaryova ◽  
O. E. Pronina
Keyword(s):  
Immune Response ◽  
Urinary Tract ◽  
Gastrointestinal Tract ◽  
Vitamin A ◽  
Developed Countries ◽  
Therapeutic Practice ◽  
The Past ◽  
Increased Risk ◽  
Mucous Membranes

Vitamin A (retinol) is one of the key elements for regulating the immune response and controls the division and differentiation of epithelial cells of the mucous membranes of the bronchopulmonary system, gastrointestinal tract, urinary tract, eyes, etc. Its significance in the context of the COVID‑19 pandemic is difficult to overestimate. However, a number of studies conducted in the past have associated the additional intake of vitamin A with an increased risk of developing cancer, as a result of which vitamin A was practically excluded from therapeutic practice in developed countries. Our review highlights the role of vitamin A in maintaining human health and the latest data on its effect on the development mechanisms of somatic pathology.

Learning Zulu

2016 ◽  
Author(s):  
Mark Sanders
Keyword(s):  
Language Learning ◽  
Cultural History ◽  
South African ◽  
Press Coverage ◽  
African History ◽  
African Culture ◽  
The Past ◽  
Correct Form ◽  
Linguistic Purism

When this book's author began studying Zulu, he was often questioned why he was learning it. This book places the author's endeavors within a wider context to uncover how, in the past 150 years of South African history, Zulu became a battleground for issues of property, possession, and deprivation. The book combines elements of analysis and memoir to explore a complex cultural history. Perceiving that colonial learners of Zulu saw themselves as repairing harm done to Africans by Europeans, the book reveals deeper motives at work in the development of Zulu-language learning—from the emergence of the pidgin Fanagalo among missionaries and traders in the nineteenth century to widespread efforts, in the twentieth and twenty-first centuries, to teach a correct form of Zulu. The book looks at the white appropriation of Zulu language, music, and dance in South African culture, and at the association of Zulu with a martial masculinity. In exploring how Zulu has come to represent what is most properly and powerfully African, the book examines differences in English- and Zulu-language press coverage of an important trial, as well as the role of linguistic purism in xenophobic violence in South Africa. Through one person's efforts to learn the Zulu language, the book explores how a language's history and politics influence all individuals in a multilingual society.

Rethinking Private Authority

2013 ◽  
Author(s):  
Jessica F. Green
Keyword(s):  
Green Building ◽  
World Politics ◽  
Multilateral Environmental Agreements ◽  
The Past ◽  
Delegation Of Authority ◽  
Private Authority ◽  
Global Environmental ◽  
Private Actors ◽  
Treaty Implementation

This book examines the role of nonstate actors in global environmental politics, arguing that a fuller understanding of their role requires a new way of conceptualizing private authority. It identifies two distinct forms of private authority—one in which states delegate authority to private actors, and another in which entrepreneurial actors generate their own rules, persuading others to adopt them. Drawing on a wealth of empirical evidence spanning a century of environmental rule making, the book shows how the delegation of authority to private actors has played a small but consistent role in multilateral environmental agreements over the past fifty years, largely in the area of treaty implementation. This contrasts with entrepreneurial authority, where most private environmental rules have been created in the past two decades. The book traces how this dynamic and fast-growing form of private authority is becoming increasingly common in areas ranging from organic food to green building practices to sustainable tourism. It persuasively argues that the configuration of state preferences and the existing institutional landscape are paramount to explaining why private authority emerges and assumes the form that it does. In-depth cases on climate change provide evidence for the book's arguments. The book demonstrates that authority in world politics is diffused across multiple levels and diverse actors, and it offers a more complete picture of how private actors are helping to shape our response to today's most pressing environmental problems.

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