scholarly journals A Novel Superabsorbent Polymer from Crosslinked Carboxymethyl Tragacanth Gum with Glutaraldehyde: Synthesis, Characterization, and Swelling Properties

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Yahya Bachra ◽  
Ayoub Grouli ◽  
Fouad Damiri ◽  
Mohammed Talbi ◽  
Mohammed Berrada
Keyword(s):  
Negative Impact ◽  
Tap Water ◽  
Crosslinking Agent ◽  
Absorption Capacity ◽  
Retention Capacity ◽  
Swelling Properties ◽  
Global Environmental Problems ◽  
Tragacanth Gum ◽  
Global Environmental ◽  
New Material

Nowadays, current global environmental problems include measures to eliminate or reduce the negative impact of chemicals from petroleum sources and, therefore, the use of materials from natural resources is increasingly recommended. In this context, natural-based superabsorbent polymers derived from polypeptides and polysaccharides have undergone chemical and biochemical modifications to improve their ability to absorb and retain large amounts of liquids. In the present paper, a new process has been used to overcome the side effects of radical polymerization in the manufacture of conventional polyacrylate superabsorbents (SAPs). Tragacanth gum (TG) was selected to prepare a new superabsorbent material (CMTG-GA) based on carboxymethyl tragacanth (CMTG) crosslinked with glutaraldehyde (GA). The characterization of the polymer was carried out by FTIR, TGA, XRD, and SEM. The effect of the amount of crosslinking agent and the pH on the water absorption capacity was also examined. Subsequently, swelling studies were performed using free swelling capacity (FSC) and centrifuge retention capacity (CRC) techniques in distilled water, tap water, and saline solution. The results showed that the CRC of the new material is not less than 42.1 g/g, which was observed for a ratio of 20% by weight of GA to CMTG. Likewise, the maximum absorption results were 43.9 and 32.14 g/g, respectively, for FSC and CRC at pH 8.0. In addition, a comparison of the swelling capacities of the synthesized product with a commercial SAP extracted from a baby diaper, well known in the Moroccan market, showed that the performances were very similar.

scholarly journals Effective Enhancement of Water Absorbency of Itaconic Acid Based-Superabsorbent Polymer via Tunable Surface—Crosslinking

Polymers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2782
Author(s):  
Yong-Rok Kwon ◽  
Jung-Soo Kim ◽  
Dong-Hyun Kim
Keyword(s):  
Itaconic Acid ◽  
Photoelectron Spectroscopy ◽  
Crosslinking Agent ◽  
Absorption Capacity ◽  
Gel Strength ◽  
Superabsorbent Polymer ◽  
Optimal Conditions ◽  
Retention Capacity ◽  
X Ray ◽  
Crosslinking Reactions

A superabsorbent polymer (SAP) was synthesized by copolymerizing itaconic acid and vinyl sulfonic acid. The typically low absorbency of itaconic acid-based SAPs under mechanical loads was improved by introducing surface crosslinking. Fourier-transform infrared spectroscopy and X-ray photoelectron spectroscopy were used to characterize the synthesis and surface-crosslinking reactions in the SAP. Various conditions for surface-crosslinking reactions, such as the surface-crosslinking solution, content of surface-crosslinking agent, and reaction temperature, were explored and correlated with the gel strength and absorption characteristics of the resulting SAP particles. The distilled water content in the surface-crosslinking solution strongly influenced the absorption capacity of the SAP, but this sensitivity decreased when acetone was used as a co-solvent. Itaconic acid-based SAP that was crosslinked under optimal conditions exhibited centrifuge retention capacity and absorbency under a load of 31.1 and 20.2, respectively.

scholarly journals The mechanism of public administration of the travel industry development: prospects for the ecotourism development

2020 ◽  
Vol 175 ◽  
pp. 10016
Author(s):  
Lyudmyla Kraynyuk ◽  
Olena Uhodnikova ◽  
Nataliia Vlashchenk ◽  
Anna Sokolenko ◽  
Kostiantyn Viatkin
Keyword(s):  
Public Administration ◽  
Negative Impact ◽  
Industry Development ◽  
Global Environmental Problems ◽  
Global Environmental ◽  
The World ◽  
Basic Approaches ◽  
Travel Industry ◽  
Development Prospects ◽  
Tourist Flow

The paper is devoted to searching ways of efficient support of public administration of the travel industry development. Tourism system has its own specific peculiarities, which influence the implementation of the functions of public administration. Among such peculiarities there are high commercialization of the branch, financial performance of investments and investment attractiveness. The paper considers trends of travel industry development, among which there are tendencies towards the increase of number of tourists, growth of tourist flow and income from travels. Trends of the travel industry development were analysed according to definite parts of the world. Also, trends in the development of ecоturism are considered. As a result of the analysis conducted the negative impact of various factors on the tourism development and aspects of improvement of the effectiveness of tourist activities. On the basis of the analysis conducted among the leading countries of the world according to the statistical data with regard to visiting by tourists, basic approaches to the construction of systems of public administration of the travel industry development were determined. Based on this analysis the proposals were made as to the improvement of public administration system in the sphere of tourism; they can be applied at the global and regional levels in order to maximize implementation of the travel industry potential and socioeconomic functions, being performed thereby in the society. The relevance of the development of ecotourism is determined, which is associated with the solution of global environmental problems.

Ecological Limits and the Meaning of Freedom: A Defense of Liberty as Non-Domination

2017 ◽  
Vol 3 (3) ◽  
pp. 33-49 ◽  
Author(s):  
Augustin Fragnière
Keyword(s):  
Conceptual Analysis ◽  
Environmental Policies ◽  
Environmental Constraints ◽  
Political Arena ◽  
Individual Liberty ◽  
Philosophical Debate ◽  
Political Issues ◽  
Global Environmental Problems ◽  
Global Environmental ◽  
Two Alternatives

It is now widely acknowledged that global environmental problems raise pressing social and political issues, but relatively little philosophical attention has been paid to their bearing on the concept of liberty. This must surprise us, because the question of whether environmental policies are at odds with individual liberty is bound to be controversial in the political arena. First, this article explains why a thorough philosophical debate about the relation between liberty and environmental constraints is needed. Second, based on Philip Pettit’s typology of liberty, it assesses how different conceptions of liberty fare in a context of stringent ecological limits. Indeed, a simple conceptual analysis shows that some conceptions of liberty are more compatible than others with such limits, and with the policies necessary to avoid overshooting them. The article concludes that Pettit’s conception of liberty as non-domination is more compatible with the existence of stringent ecological limits than the two alternatives considered.

Theoretical Ecology

2007 ◽  
Keyword(s):  
Spatial Dynamics ◽  
Theory And Practice ◽  
The Novel ◽  
Basic Principles ◽  
Theoretical Ecology ◽  
Global Environmental Problems ◽  
Global Environmental ◽  
Interacting Populations ◽  
Novel Material ◽  
Ecological Science

Robert May's seminal book has played a central role in the development of ecological science. Originally published in 1976, this influential text has overseen the transition of ecology from an observational and descriptive subject to one with a solid conceptual core. Indeed, it is a testament to its influence that a great deal of the novel material presented in the earlier editions has now been incorporated into standard undergraduate textbooks. It is now a quarter of a century since the publication of the second edition, and a thorough revision is timely. Theoretical Ecology provides a succinct, up-to-date overview of the field set in the context of applications, thereby bridging the traditional division of theory and practice. It describes the recent advances in our understanding of how interacting populations of plants and animals change over time and space, in response to natural or human-created disturbance. In an integrated way, initial chapters give an account of the basic principles governing the structure, function, and temporal and spatial dynamics of populations and communities of plants and animals. Later chapters outline applications of these ideas to practical issues including fisheries, infectious diseases, tomorrow's food supplies, climate change, and conservation biology. Throughout the book, emphasis is placed on questions which as yet remain unanswered. The editors have invited the top scientists in the field to collaborate with the next generation of theoretical ecologists. The result is an accessible, advanced textbook suitable for senior undergraduate and graduate level students as well as researchers in the fields of ecology, mathematical biology, environmental and resources management. It will also be of interest to the general reader seeking a better understanding of a range of global environmental problems.

Is There a Future for Bourgeois Liberalism?

2019 ◽  
pp. 109-129
Author(s):  
Robert J. Antonio
Keyword(s):  
Capital Accumulation ◽  
Free Market ◽  
Political Legitimacy ◽  
Corporate Scandals ◽  
Global Environmental Problems ◽  
Global Environmental ◽  
Free Market Capitalism ◽  
Formal Rationality ◽  
Bourgeois Culture ◽  
Neoliberal Restructuring

Distinguished by extreme, systematized rationalism, Weber argued, bourgeois culture makes the social world in some ways more predictable and more comfortable but precludes a widely shared good life and social justice. He stressed emphatically that free-market capitalism, by maximizing formal rationality oriented to capital accounting and profitability, produces substantively “irrational” consequences that undermine the sociocultural and material fabric needed to sustain it. More than forty years of neoliberal restructuring, designed to accelerate capital accumulation at almost any cost, has generated massive corporate scandals, extreme economic inequalities, and global environmental problems that threaten its political legitimacy and social and ecological foundations. This chapter explores how Weber anticipated the types of substantive irrationalities suffered by today’s neoliberal regimes.

scholarly journals Polyphenol Profiling of Chestnut Pericarp, Integument and Curing Water Extracts to Qualify These Food By-Products as a Source of Antioxidants

Molecules ◽  
2021 ◽  
Vol 26 (8) ◽  
pp. 2335
Author(s):  
Gabriella Pinto ◽  
Sabrina De Pascale ◽  
Maria Aponte ◽  
Andrea Scaloni ◽  
Francesco Addeo ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Negative Impact ◽  
Tap Water ◽  
Time Of Flight ◽  
The Other ◽  
Curing Process ◽  
Flight Mass Spectrometry ◽  
Water Curing ◽  
The Impact ◽  
By Products

Plant polyphenols have beneficial antioxidant effects on human health; practices aimed at preserving their content in foods and/or reusing food by-products are encouraged. The impact of the traditional practice of the water curing procedure of chestnuts, which prevents insect/mould damage during storage, was studied to assess the release of polyphenols from the fruit. Metabolites extracted from pericarp and integument tissues or released in the medium from the water curing process were analyzed by matrix-assisted laser desorption ionization-time of flight-mass spectrometry (MALDI-TOF-MS) and electrospray-quadrupole-time of flight-mass spectrometry (ESI-qTOF-MS). This identified: (i) condensed and hydrolyzable tannins made of (epi)catechin (procyanidins) and acid ellagic units in pericarp tissues; (ii) polyphenols made of gallocatechin and catechin units condensed with gallate (prodelphinidins) in integument counterparts; (iii) metabolites resembling those reported above in the wastewater from the chestnut curing process. Comparative experiments were also performed on aqueous media recovered from fruits treated with processes involving: (i) tap water; (ii) tap water containing an antifungal Lb. pentosus strain; (iii) wastewater from a previous curing treatment. These analyses indicated that the former treatment determines a 6–7-fold higher release of polyphenols in the curing water with respect to the other ones. This event has a negative impact on the luster of treated fruits but qualifies the corresponding wastes as a source of antioxidants. Such a phenomenon does not occur in wastewater from the other curing processes, where the release of polyphenols was reduced, thus preserving the chestnut’s appearance. Polyphenol profiling measurements demonstrated that bacterial presence in water hampered the release of pericarp metabolites. This study provides a rationale to traditional processing practices on fruit appearance and qualifies the corresponding wastes as a source of bioactive compounds for other nutraceutical applications.

Science Diplomacy in the Twentieth Century: Introduction

2021 ◽  
pp. 002200942110067
Author(s):  
Soenke Kunkel
Keyword(s):  
Twentieth Century ◽  
Foreign Policy ◽  
Foreign Relations ◽  
Special Section ◽  
Contemporary History ◽  
Global Environmental Problems ◽  
Global Environmental ◽  
Science Diplomacy ◽  
The Cold War

Setting the stage for the special forum, this introduction points to the centrality of science diplomacy activities within many current foreign policy concepts around the world. It also points to the lack of historical perspective within many current academic debates about science diplomacy. Suggesting the value of such a perspective, the introduction then draws attention to a number of fruitful contributions that histories of science diplomacy may make to contemporary history. These include: a better understanding of how entanglements between science, foreign policy, and international relations evolved over the twentieth century; a refined understanding of the workings of foreign relations and diplomacy that sheds light on the role of science as an arena of foreign relations; new insights into the Cold War; a globalizing of perspectives in the writing of contemporary history; a new international focus on widely under-researched actors like universities, science movements, science organizations, and science academies; a focus on new themes that range from global environmental problems to issues like cultural heritage. The remainder of the introduction then delineates some of the shared assumptions and findings of the essays and then briefly introduces each contribution to the special section.

scholarly journals Impact of Environmental Moral Education on Pro-Environmental Behaviour: Do Psychological Empowerment and Islamic Religiosity Matter?

2021 ◽  
Vol 18 (4) ◽  
pp. 1604
Author(s):  
Abida Begum ◽  
Liu Jingwei ◽  
Maqsood Haider ◽  
Muhammad Maroof Ajmal ◽  
Salim Khan ◽  
...  
Keyword(s):  
Moral Education ◽  
Structural Equation ◽  
Psychological Empowerment ◽  
Analytical Techniques ◽  
Cross Sectional ◽  
Environmental Behaviour ◽  
Mediating Role ◽  
Global Environmental Problems ◽  
Global Environmental ◽  
The Relationship

In light of increasing concerns about global environmental problems, environmental moral education is assumed to have a significant influence on the pro-environmental behaviour of students. Within the past decade, several higher education institutes have acknowledged the importance of integrating sustainability into the educational curriculum to have a focused and explicit impact on society. The current study investigated the relationship between environmental moral education and pro-environmental behaviour while drawing upon insights from the conservation of resource theory. The relationship among the aforementioned variables was studied for the mediating role of psychological empowerment and the moderating effect of Islamic religiosity. Data were collected from 429 university students with a cross-sectional approach. The data were analysed using “structural equation modelling” and “PROCESS” analytical techniques. The results of the study followed the predicted conceptual model, that is, environmental moral education was positively related to pro-environmental behaviour. Furthermore, psychological empowerment partially mediated the aforementioned relationship, while Islamic religiosity moderated the relationships between environmental moral education and pro-environmental behaviour as well as between environmental moral education and psychological empowerment. These findings reinforce the importance of environmental moral education and Islamic religiosity in understanding the Muslim student’s ecological behaviours.

scholarly journals Astronomy to understand a human environment

1998 ◽  
Vol 162 ◽  
pp. 211-213
Author(s):  
S. Isobe
Keyword(s):  
School System ◽  
Environmental Science ◽  
The Other ◽  
Human Environment ◽  
Science Courses ◽  
The Public ◽  
Global Environmental Problems ◽  
Global Environmental ◽  
Set Up ◽  
School Period

Astronomy is an important science in understanding a human environment. However, it is thought by most politicians, economists, and members of the public that astronomy is a pure science having no contribution to daily human activities except a few matters relating to time. The Japanese government is studying a reorganisation of our school system to have 5 school days per week, instead of 6 days per week, and this July its committee made a recommendation to reduce school hours for science and set up new courses for practical computers and environmental science. I currently made a proposal. It is very difficult for most of the school pupils, who will have non-scientific jobs, to understand science courses currently taught in school, because each science is taught independently from the other sciences. Therefore, their knowledge of sciences obtained during their school period does not greatly help their understanding of global environmental problems.

Sign in / Sign up

Export Citation Format

Share Document