scholarly journals Recent Advances in Fabrication of Non-Isocyanate Polyurethane-Based Composite Materials

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3497
Author(s):  
Piotr Stachak ◽  
Izabela Łukaszewska ◽  
Edyta Hebda ◽  
Krzysztof Pielichowski
Keyword(s):  
Raw Materials ◽  
Synthesis Method ◽  
Polymeric Materials ◽  
Original Research ◽  
Significant Group ◽  
Oh Groups ◽  
New Class ◽  
Hazardous Chemical ◽  
Wide Range

Polyurethanes (PUs) are a significant group of polymeric materials that, due to their outstanding mechanical, chemical, and physical properties, are used in a wide range of applications. Conventionally, PUs are obtained in polyaddition reactions between diisocyanates and polyols. Due to the toxicity of isocyanate raw materials and their synthesis method utilizing phosgene, new cleaner synthetic routes for polyurethanes without using isocyanates have attracted increasing attention in recent years. Among different attempts to replace the conventional process, polyaddition of cyclic carbonates (CCs) and polyfunctional amines seems to be the most promising way to obtain non-isocyanate polyurethanes (NIPUs) or, more precisely, polyhydroxyurethanes (PHUs), while primary and secondary –OH groups are being formed alongside urethane linkages. Such an approach eliminates hazardous chemical compounds from the synthesis and leads to the fabrication of polymeric materials with unique and tunable properties. The main advantages include better chemical, mechanical, and thermal resistance, and the process itself is invulnerable to moisture, which is an essential technological feature. NIPUs can be modified via copolymerization or used as matrices to fabricate polymer composites with different additives, similar to their conventional counterparts. Hence, non-isocyanate polyurethanes are a new class of environmentally friendly polymeric materials. Many papers on the matter above have been published, including both original research and extensive reviews. However, they do not provide collected information on NIPU composites fabrication and processing. Hence, this review describes the latest progress in non-isocyanate polyurethane synthesis, modification, and finally processing. While focusing primarily on the carbonate/amine route, methods of obtaining NIPU are described, and their properties are presented. Ways of incorporating various compounds into NIPU matrices are characterized by the role of PHU materials in copolymeric materials or as an additive. Finally, diverse processing methods of non-isocyanate polyurethanes are presented, including electrospinning or 3D printing.

ETHNOBOTANICAL RESEARCH OF THE PERSPECTIVE MEDICINAL PLANT OFCISTANCHE SALSA (С.А. МEY.) G. BECK

Vestnik ◽  
2021 ◽  
pp. 252-255
Author(s):  
Д.К. Айдарбаев ◽  
А.Ж. Жарқынбек
Keyword(s):  
Medicinal Plant ◽  
Raw Materials ◽  
Folk Medicine ◽  
Climatic Conditions ◽  
Pharmacological Properties ◽  
Ecological Features ◽  
Wide Range ◽  
The Family ◽  
Research Recommendations

В статье рассматриваются биологические и экологические особенности цистанхе, а также предусматривается этноботанические исследования, рекомендации по рациональному использованию. Выявлены некоторые значения Cistanchе, которое произрастает в Казахстане. Определена область использования в народной медицине цистанхе из семейства Orobanchaceae. В исследовании показана роль цистанхе, как растения с широким спектром фармакологических свойств. Проведен анализ маршрутно-рекогносцировочных исследований популяции цистанхе, определены распределение, запасы и объемы ежегодных заготовок по основным расположенным флористическим районам. Проведен расчет среднего суммарного объема заготовок сырья, собранных в Прибалхашье Алматинской области. В настоящее время в результате глобального потепления климатические условия меняются, и многие виды растений вымирают. Поэтому защита и эффективное использование растений является одной из самых актуальных проблем. Также важно изучить цистанхе, используемый в народной медицине как лекарственное растение. The article discusses the biological and ecological features of cistanche, as well as provides for ethnobotanical research, recommendations for rational use. Some values of Cistanche, which grows in Kazakhstan, are revealed. The scope of use in folk medicine of cistanha from the family Orobanchaceae is determined. The study shows the role of cistanche as a plant with a wide range of pharmacological properties. Conducted analysis of route-reconnaissance studies of cisterna populations, determined the distribution, stock and volumes of annual preparations for the main floristic areas. Calculated the average total volume of raw materials collected in the Balkhash region of Almaty region. As a result of global warming, climatic conditions are changing and many plant species are dying. Therefore, the protection and efficient use of plants is one of the most pressing problems. It is also important to study the tanks used in folk medicine as a medicinal plant.

scholarly journals The Role of Quality of Education in Neurocognitive Functioning in a Diverse Sample with Chronic Opioid Use Disorder

2019 ◽  
Vol 34 (7) ◽  
pp. 1269-1269
Author(s):  
J Olsen ◽  
J Arnsten ◽  
T Scott ◽  
F Arias ◽  
C Zhang ◽  
...  
Keyword(s):  
Executive Functioning ◽  
Opioid Use Disorder ◽  
Reading Level ◽  
Quality Of Education ◽  
Opioid Use ◽  
Significant Group ◽  
Wide Range ◽  
Chronic Opioid Use

Abstract Objective Literacy is a proxy for quality of education (QoE) and mediates ethnicity-related differences in neurocognitive (NC) performance in some populations (Manly et al., 2002; Rivera Mindt et al., 2008). However, it is unknown whether this relationship exists in the context of chronic opioid use disorder (OUD). This study examined the role of ethnicity, QoE, opioid use severity, and depression in predicting NC performance in a diverse sample of persons with OUD. Participants and Method This cross-sectional study included 74 adults with OUD (Age M = 40.3 [SD = 10.5]; Education M = 11.3 [2.5]; 24% female; 68% Latinx and 32% Non-Latinx White [NLW]). All participants completed comprehensive NC testing and psychiatric/substance use questionnaires. Variables included ethnicity (Latinx vs. Non-Latinx White), years of education, QoE (Wide Range Achievement Test, Third Edition; WRAT-3 Reading Standard Scores), opioid use severity (high vs. low OAT dose), current depression (Beck Depression Inventory, Second Edition; BDI-II Total Score), and demographically-corrected NC T-scores were computed and used for average domain T-scores (e.g., learning, memory, verbal fluency, executive function). Bivariate and ANCOVA analyses were used to compare ethnic groups. Results There were no significant group differences on opioid use severity or current depression (p’s > .05). However, compared to the NLW group, the Latinx group had lower years of education (M = 10.9 [SD = 1.7] vs. M = 12.2 [SD = 3.5]; t[72)] = 2.1, p < .05), QoE (M = 83.1 [SD = 13.6] vs. M = 94.8 [SD = 9.4]; t[72] = 3.8, p < .001), executive functioning (M = 42.0 [SD = 6.5] vs. M = 45.8 [SD = 8.5]; t[72) = 2.1, p < .05), and learning (M = 32.2 [SD = 8.2] vs. M = 37.8 [SD = 8.7]; t[72)] = 2.7, p < .05), with medium to large effect sizes (Cohen’s d > .50). The overall effect of ethnicity became non-significant for executive functioning after accounting for QoE (F[2,70] = 10.0, p = .002) and years of education (F[2,70)] = 16.8, p < .001). Conclusions The current study found that accounting for years of education and QoE attenuates some differences in NC performance between Latinx and Non-Latinx participants. References Manly, J. J., Jacobs, D. M., Touradji, P., Small, S. A., & Stern, Y. (2002). Reading level attenuates differences in neuropsychological test performance between African American and White elders. Journal of the International Neuropsychological Society, 8(3), 341-348. Mindt, M. R., Arentoft, A., Germano, K. K., D’Aquila, E., Scheiner, D., Pizzirusso, M., ... & Gollan, T. H. (2008). Neuropsychological, cognitive, and theoretical considerations for evaluation of bilingual individuals. Neuropsychology review, 18(3), 255-268.

Tacit vs explicit knowledge as antecedents for organizational change

2020 ◽  
Vol 33 (6) ◽  
pp. 1123-1141
Author(s):  
Jordan R. Gamble
Keyword(s):  
Organizational Change ◽  
Knowledge Management ◽  
Explicit Knowledge ◽  
Theoretical Development ◽  
Original Research ◽  
Content Type ◽  
Wide Range ◽  
Management Literature ◽  
Tacit And Explicit Knowledge

PurposeThe aim of this paper is to explore the dichotomous role of knowledge through an examination of tacit and explicit knowledge in organizational change contexts.Design/methodology/approachThe study's aim is achieved by an analytical review of the seminal and contemporary knowledge management literature.FindingsThe paper contributes to the current body of knowledge management literature by analyzing a wide range of key literature and presenting a contemporary overview that compares the role of tacit and explicit knowledge within organizational change contexts.Research limitations/implicationsThe findings contribute toward theoretical development in the knowledge management field by providing researchers with future research directions to build upon previous theoretical understandings and advance our collective knowledge of the research domain.Practical implicationsThe paper offers practical and pragmatic insights that will help firm managers to use tacit and/or explicit knowledge to manage organizational change.Originality/valueThis article presents an original comparative table that summarizes and compares the key understandings and insights from across the literature sources on a range of important aspects, and then presents implications for the two knowledge typologies. The paper also presents an original research framework containing a structured database of related calls for research by the latest academic publications. Furthermore, it provides specific and informed managerial recommendations for best practice in the integration of these knowledge typologies into organizational change management.

scholarly journals RESEARCH OF PROPERTIES, STRUCTURAL FEATURES AND TECHNOLOGICAL POSSIBILITIES OF NEW POLYMERIC MATERIALS FOR FILLING-RETANNING OF LEATHER

2021 ◽  
Vol 297 (3) ◽  
pp. 162-167
Author(s):  
OLGA ANDREYEVA ◽  
NATALIIA PERVAIA ◽  
INNA LOSHKAREVA ◽  
NATALIA CHUMAKOVA ◽  
Keyword(s):  
Raw Materials ◽  
Inorganic Compounds ◽  
Polymeric Materials ◽  
Structural Features ◽  
Polymer Materials ◽  
Melamine Formaldehyde ◽  
Sulfur Silicon ◽  
Oh Groups ◽  
Positive Effect

The paper presents the results of research of two new industrial polymer materials in the form of the Syntan RS3L product and the Syntan F187 product. It has been experimentally established that these materials differ in appearance, structure, and physicochemical properties. So, the first product is a solution of polyacrylates and is well compatible with water, while the second product is a synthetic composition of melamine-formaldehyde resins and inorganic compounds based on aluminium, iron, potassium, sulfur, silicon in the form of a powder, which is partially soluble in water. Using the method of infrared spectroscopy, the features of the structure of polymeric materials are determined – the presence of various groups and bonds, which indicates the polyfunctional nature of both reagents. It was found that after treatment of a chrome tanned collagen preparation with Syntan LF187, the optical density in the IR spectrum of collagen changes to the greatest extent at a frequency of 876-873 cm-1, which corresponds to stretching vibrations of O-O groups of peroxides in the protein structure. When exposed to the Syntan RS3 product, significant changes are observed in the frequency range 1240-1235 cm-1, which corresponds to the stretching and deformation vibrations of the nitrogen-containing Amide II groups, amines and OH groups of alcohols. When studying the technological capabilities of polymeric materials as reagents for filling and retanning chrome tanned leather for shoe uppers from cattle raw materials, it was found that, according to the organoleptic assessment and the indicator of the generalized objective function, the best were leather samples processed with 2.0 % of the Syntan RS3 product. The results obtained can be explained by the peculiarities of the distribution and interaction of materials in the structure of the dermis, the essence of which is the formation of strong and at the same time flexible bonds, which has a positive effect on the formation of the structure and quality indicators of leather. To confirm the obtained data, it is planned to conduct semi-production tests. It is expected that the quality of the finished product will improve, and the existing vegetable and synthetic tanning agents will be replaced with a modern, more efficient and environmentally friendly polymer material.

scholarly journals Dendrimers: properties and applications.

2001 ◽  
Vol 48 (1) ◽  
pp. 199-208 ◽  
Author(s):  
B Klajnert ◽  
M Bryszewska
Keyword(s):  
Chemical Properties ◽  
Polymeric Materials ◽  
Industrial Applications ◽  
New Class ◽  
Research Technology ◽  
Concise Review ◽  
Physico Chemical ◽  
Wide Range ◽  
Physical And Chemical ◽  
And Chemical Properties

Dendrimers are a new class of polymeric materials. They are highly branched, monodisperse macromolecules. The structure of these materials has a great impact on their physical and chemical properties. As a result of their unique behaviour dendrimers are suitable for a wide range of biomedical and industrial applications. The paper gives a concise review of dendrimers' physico-chemical properties and their possible use in various areas of research, technology and treatment.

Investigation to Obtain Polyols from Residual Frying Oil

2014 ◽  
Vol 775-776 ◽  
pp. 351-356 ◽  
Author(s):  
Luiz Gustavo Ferraro ◽  
Felipe Bastos de Souza Alvarenga ◽  
Maria Virginia Gelfuso ◽  
Daniel Thomazini
Keyword(s):  
Hydrogen Peroxide ◽  
Raw Materials ◽  
Polymeric Materials ◽  
Frying Oil ◽  
Food Sources ◽  
Renewable Raw Materials ◽  
Oh Groups ◽  
Ft Ir ◽  
New Research ◽  
Hydroxylation Index

. Polymeric materials based on petroleum have generated a major problem for the environment because they are produced by non-renewable sources. Many studies are being conducted to propose alternatives to obtain polymers from renewable raw materials sources. The disadvantage of this alternative is the use of food sources for polymer production but this is avoided when using the residual frying oil. Aiming to obtain polymer-based urethanes, pretreated residual frying oil samples were submitted to various conditions of hydroxylation and analyzed by FT-IR, where it was possible to observe the presence of-OH groups. To optimize the process of hydroxylation a new research was conducted to determine the concentrations of formic acid and hydrogen peroxide that can generate polyols with high levels of hydroxylation index, suitable for the formation of urethanes.

scholarly journals Role of Yeasts in the Brewing Process: Tradition and Innovation

Processes ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 839
Author(s):  
Massimo Iorizzo ◽  
Francesca Coppola ◽  
Francesco Letizia ◽  
Bruno Testa ◽  
Elena Sorrentino
Keyword(s):  
Raw Materials ◽  
Metabolic Characteristics ◽  
Organoleptic Characteristics ◽  
Wide Range ◽  
Brewing Process ◽  
Materials Used ◽  
Definition Of ◽  
New Yeast ◽  
Saccharomyces Yeasts

Nowadays, in the beer sector, there is a wide range of products, which differ for the technologies adopted, raw materials used, and microorganisms involved in the fermentation processes. The quality of beer is directly related to the fermentation activity of yeasts that, in addition to the production of alcohol, synthesize various compounds that contribute to the definition of the compositional and organoleptic characteristics. The microbrewing phenomenon (craft revolution) and the growing demand for innovative and specialty beers has stimulated researchers and brewers to select new yeast strains possessing particular technological and metabolic characteristics. Up until a few years ago, the selection of starter yeasts used in brewing was exclusively carried out on strains belonging to the genus Saccharomyces. However, some non-Saccharomyces yeasts have a specific enzymatic activity that can help to typify the taste and beer aroma. These yeasts, used as a single or mixed starter with Saccharomyces strains, represent a new biotechnological resource to produce beers with particular properties. This review describes the role of Saccharomyces and non-Saccharomyces yeasts in brewing, and some future biotechnological perspectives.

Inorganic Polymeric Materials Based on Natural Silicate and Aluminosilicate Raw Materials

2022 ◽  
Vol 906 ◽  
pp. 1-6
Author(s):  
Emma Sahakyan ◽  
Avetik Arzumanyan ◽  
Nelli Muradyan
Keyword(s):  
Kinetic Parameters ◽  
Building Materials ◽  
Raw Materials ◽  
Volcanic Rocks ◽  
Polymeric Materials ◽  
Reaction Rate Constant ◽  
Product Layer ◽  
Conversion Degree ◽  
Wide Range ◽  
Energy Conserving

The prospects of implementing the mechanochemical activation method of volcanic silicate and aluminosilicate rocks - perlites, tuffs, pumice, etc. are being considered for the production of a wide range of building materials using energy-conserving technologies. The thermodynamic and kinetic parameters of interaction in the systems of aluminosilicate – NaOH have been presented, indicating low-temperature sintering of volcanic rocks with sodium hydroxide. According to the degree of activity, the rocks have the following order: perlites, tuffs, obsidian, microcline. Kinetic parameters are presented: concentration, temperature, conversion degree, reaction rate constant, time of complete reaction and product layer thickness.

scholarly journals Versatile Role of Prokineticins and Prokineticin Receptors in Neuroinflammation

Biomedicines ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 1648
Author(s):  
Roberta Lattanzi ◽  
Rossella Miele
Keyword(s):  
Inflammatory Cytokines ◽  
Adaptive Responses ◽  
New Class ◽  
Prokineticin 2 ◽  
Wide Range ◽  
Gastrointestinal Inflammation ◽  
Low Levels ◽  
Inflammatory Component ◽  
Pro Inflammatory Cytokines

Prokineticins are a new class of chemokine-like peptides involved in a wide range of biological and pathological activities. In particular, prokineticin 2 (PK2), prokineticin receptor 1 (PKR1) and prokineticin receptor 2 (PKR2) play a central role in modulating neuroinflammatory processes. PK2 and PKRs, which are physiologically expressed at very low levels, are strongly upregulated during inflammation and regulate neuronal-glial interaction. PKR2 is mainly overexpressed in neurons, whereas PKR1 and PK2 are mainly overexpressed in astrocytes. Once PK2 is released in inflamed tissue, it is involved in both innate and adaptive responses: it triggers macrophage recruitment, production of pro-inflammatory cytokines, and reduction of anti-inflammatory cytokines. Moreover, it modulates the function of T cells through the activation of PKR1 and directs them towards a pro-inflammatory Th1 phenotype. Since the prokineticin system appears to be upregulated following a series of pathological insults leading to neuroinflammation, we will focus here on the involvement of PK2 and PKRs in those pathologies that have a strong underlying inflammatory component, such as: inflammatory and neuropathic pain, Alzheimer’s disease, Parkinson’s disease, multiple sclerosis, stroke, obesity, diabetes, and gastrointestinal inflammation.

scholarly journals Pretreatment of Plastic Waste: Removal of Colorants from HDPE Using Biosolvents

Molecules ◽  
2021 ◽  
Vol 27 (1) ◽  
pp. 98
Author(s):  
Ana M. Ferreira ◽  
Isa Sucena ◽  
Vanessa Otero ◽  
Eva Mariasole Angelin ◽  
Maria João Melo ◽  
...  
Keyword(s):  
Raw Materials ◽  
Plastic Waste ◽  
Secondary Source ◽  
Lower Grade ◽  
Recycling Process ◽  
Oh Groups ◽  
Wide Range ◽  
Plastic Matrix ◽  
Recycled Material

Plastics recycling remains a challenge due to the relatively low quality of the recycled material, since most of the developed recycling processes cannot deal with the additives present in the plastic matrix, so the recycled products end up in lower-grade applications. The application of volatile organic solvents for additives removal is the preferred choice. In this study, pretreatment of plastic packaging waste to remove additives using biosolvents was investigated. The plastic waste used was high-density polyethylene (HDPE) with blue and orange colorants (pigment and/or dye). The first step was to identify the type of colorants present in the HDPE, and we found that both plastics presented only one colorant that was actually a pigment. Then, limonene, a renewable solvent, was used to solubilize HDPE. After HDPE dissolution, a wide range of alcohols (mono-, di-, and tri-alcohols) was evaluated as antisolvents in order to selectively precipitate the polymer and maximize its purity. The use of limonene as solvent for plastic dissolution, in combination with poly-alcohols with an intermediate alkyl chain length and a large number of hydroxyl (OH) groups, was found to work best as an antisolvent (1,2,3-propanetriol and 1,2,4-butanetriol), leading to a removal of up to 94% and 100% of the blue and orange pigments, respectively. Finally, three cycles of extraction were carried out, proving the capability of the solvent and antisolvent to be recovered and reused, ensuring the economic viability and sustainability of the process. This pretreatment provides a secondary source of raw materials and revenue for the recycling process, which may lead to an increase in the quality of recycled polymers, contributing to the development of an economical and sustainable recycling process.

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