scholarly journals Oxidation Catalysis in Clean Technologies for Fine Chemicals

2017 ◽  
Vol 3 (4) ◽  
pp. 221 ◽  
Author(s):  
S. Albonetti ◽  
L. Dal Pozzo ◽  
F. Trifirò
Keyword(s):  
Hydrogen Peroxide ◽  
Point Of View ◽  
Oxidation Catalysis ◽  
Fine Chemicals ◽  
Industrial Chemistry ◽  
Heterogeneous Oxidation ◽  
Mild Conditions ◽  
Research Perspectives ◽  
Wide Range ◽  
Metal Doped

The role of heterogeneous catalysis for the production of fine chemicals is reviewed with particular interest for the oxidation in a wide range of aspects of this kind of processes: reaction of oxygen insertion, oxidative dehydrogenation and nitrogen insertion (with ammonia and oxygen). In this review are examined the main processes industrially applied and the best research perspectives in the field of heterogeneous oxidation catalysis for the synthesis of fine chemicals. It is an important point of view in relation with the typical parameters of this field of industrial chemistry and in relation with the driving force of environmental friendly technologies (the line guides of green chemistry) to substitute traditional processes. It is examined either the possibility of the use of gas phases, that is better on an economical and plant point of view, with molecular oxygen, nitrous oxide (it is a very specific oxidant, and it is active in mild conditions) and with the technique of short bed reactor to minimise the effects of the consecutive oxidation reaction particularly on aromatic side chains. Or the use of liquid phases, very useful to work in mild conditions with not stable reagents, with hydrogen peroxide and other alternative oxidants such as regenerable organic hydroperoxides. In the liquid phase reactions it is posed a particular interest in the oxidations carried out with the use of metal doped zeolites, with special attention to tianiasilica catalysts such as TS-1 with the new developments of hydrogen peroxide in situ generation; and heteropoly compounds.

scholarly journals History of Ukrainian Peasantry of the Dnipro Ukraine in the Research Perspectives of Postgumnism

2018 ◽  
Vol 1 ◽  
pp. 141
Author(s):  
Yurii Prysyazhnyuk
Keyword(s):  
Point Of View ◽  
Modern World ◽  
Post Colonial ◽  
Peasant Studies ◽  
Colonial Studies ◽  
Agrarian Society ◽  
Research Areas ◽  
Research Perspectives ◽  
Wide Range ◽  
Post Humanism

Modern Ukrainian historiography of the peasantry is in a position where both modern and postmodern researches are recognized as the scientifically capable ones for proper methodological substantiation and presentation. And while science, as it is known, seeks to focus on innovations that are characterized by greater productivity, convincing argumentation, all of them can still rely on an interested reader. Given this and some other circumstances, the proposed intelligence is a kind of attempt to show how against the backdrop of little apparent crisis phenomena in the methodology of history seem to be efforts aimed at the research prospects of post-human studies. The historiographic feature of intelligence is the author's appeal to a rather wide range of studies of European (more general – Western) scholars, who in the article presented primarily a collection of well – known Polish historians Eve Domanska and Tomas Vyslich. Post-humanism is presented as a complex of institutionalized tendencies and research areas, thoughtfully, intellectually and ethically connected with it. She claims a wide range of "reformal changes" in the methodology of creating historical knowledge, but has not yet been confirmed as a dominant (or even recognized) paradigm. Accordingly, the author tries to find out how scientifically substantiated abandonment of the principles of modernism opens the prospect of a more reliable understanding of the modern world. Critics are subjected to the principles established in modern Ukrainian historiography as anthropocentrism and secularization. They are known to have caused a lot of interpretative inconvenience to researchers in the agrarian society. Qualitative thinking also requires the usual term "Ukrainian peasantry". It loses its widespread significance, because artificially, and therefore, from a scientific point of view it is not justified to "modernize" the peasant traditional world. Post Humanism recognizes the expediency of post-colonial studies. From the point of view of the needs of Ukrainian peasant studies, this is understandable, if we consider that the modernist professed Eurocentrism, it does not refuse from its prevalence, even though it includes both post-European and post-colonial initiatives. In the end, historians (historiographers) will love to "emphasize" under the next flash of activization of peasant studies. Such statements also provoke the logic of creating mega-narratives, since each block of such intellectual products claims to be some kind of (or desired) completeness. The author argues that post humanism destroys this tradition, opens up new horizons for interpreting the past of an "awkward class".

Colorimetric research of self-luminous objects in software and hardware environments by the method of multidimensional scales implementation

2020 ◽  
pp. 43-50
Author(s):  
Yauheniya N. Saukova
Keyword(s):  
Metrological Traceability ◽  
Point Of View ◽  
Intermediate Precision ◽  
Technical Vision ◽  
Wide Range ◽  
Chromaticity Coordinates ◽  
Unity Of Measurements ◽  
Software And Hardware ◽  
Luminous Objects ◽  
Reference Samples

It is shown that the issues of metrological traceability for extended self-luminous objects with a wide range of brightness have not yet been resolved, since the rank scales of embedded systems are used for processing digital images. For such scales, there is no “fixed” unit, which does not allow you to get reliable results and ensure the unity of measurements. An experiment is described to evaluate the accuracy of determining the intensity (coordinates) of the color of self-luminous objects. In terms of repeatability and intermediate precision compared to the reference measurement method, the color and chromaticity coordinates of self-luminous objects (reference samples) were determined by their multiple digital registration using technical vision systems. The possibilities of the developed methodology for colorimetric studies in hardware and software environments from the point of view of constructing a multidimensional conditional scale are determined.

COMBINATORIAL POLYNOMIALLY COMPUTABLE CHARACTERISTICS OF SUBSTITUTIONS AND THEIR PROPERTIES

2020 ◽  
Vol 7 (2) ◽  
pp. 34-41
Author(s):  
VLADIMIR NIKONOV ◽  
◽  
ANTON ZOBOV ◽  
Keyword(s):  
Mathematical Expectation ◽  
Point Of View ◽  
Small Range ◽  
Computational Point ◽  
Wide Range ◽  
Bijective Function ◽  
The Difference ◽  
Element Base ◽  
Selection Of

The construction and selection of a suitable bijective function, that is, substitution, is now becoming an important applied task, particularly for building block encryption systems. Many articles have suggested using different approaches to determining the quality of substitution, but most of them are highly computationally complex. The solution of this problem will significantly expand the range of methods for constructing and analyzing scheme in information protection systems. The purpose of research is to find easily measurable characteristics of substitutions, allowing to evaluate their quality, and also measures of the proximity of a particular substitutions to a random one, or its distance from it. For this purpose, several characteristics were proposed in this work: difference and polynomial, and their mathematical expectation was found, as well as variance for the difference characteristic. This allows us to make a conclusion about its quality by comparing the result of calculating the characteristic for a particular substitution with the calculated mathematical expectation. From a computational point of view, the thesises of the article are of exceptional interest due to the simplicity of the algorithm for quantifying the quality of bijective function substitutions. By its nature, the operation of calculating the difference characteristic carries out a simple summation of integer terms in a fixed and small range. Such an operation, both in the modern and in the prospective element base, is embedded in the logic of a wide range of functional elements, especially when implementing computational actions in the optical range, or on other carriers related to the field of nanotechnology.

Double Ring-Closing Approach for the Synthesis of 2,3,6,7-Substituted Anthracene Derivatives

2020 ◽  
Author(s):  
Birgit Meindl ◽  
Katharina Pfennigbauer ◽  
Berthold Stöger ◽  
Martin Heeney ◽  
Florian Glöcklhofer
Keyword(s):  
Wittig Reaction ◽  
Condensation Reaction ◽  
Synthetic Methods ◽  
Anthracene Derivative ◽  
Double Ring ◽  
Mild Conditions ◽  
Wide Range ◽  
Anthracene Derivatives

Anthracene derivatives have been used for a wide range of applications and many different synthetic methods for their preparation have been developed. However, despite continued synthetic efforts, introducing substituents in some positions has remained difficult. Here we present a method for the synthesis of 2,3,6,7-substituted anthracene derivatives, one of the most challenging anthracene substitution patterns to obtain. The method is exemplified by the preparation of 2,3,6,7-anthracenetetracarbonitrile and employs a newly developed, stable protected 1,2,4,5-benzenetetracarbaldehyde as the precursor. The precursor can be obtained in two scalable synthetic steps from 2,5-dibromoterephthalaldehyde and is converted into the anthracene derivative by a double intermolecular Wittig reaction under very mild conditions followed by a deprotection and intramolecular double ring-closing condensation reaction. Further modification of the precursor is expected to enable the introduction of additional substituents in other positions and may even enable the synthesis of fully substituted anthracene derivatives by the presented approach.<br>

Academy Journal No.3(15), 2019/ Chief Editors Susan Belih & Jaak Järv /OEAPS Inc.(Open European Academy of Public Sciences) & Estonian Academy of Sciences. Tallinn, Estonia. 09.03.2019: OEAPS Inc., 2019. - 88 P. ISBN: 9781797440507 ISSN 1736-7530 (electronic)

2019 ◽  
Author(s):  
Inc. OEAPS
Keyword(s):  
Service Sector ◽  
Point Of View ◽  
Scientific Quality ◽  
Final Decision ◽  
Research Subjects ◽  
Wide Range ◽  
Peer Reviewers ◽  
Verification Process ◽  
Scientific Research Articles ◽  
Monthly Journal

"Academy Journal" is an international, peer-reviewed monthly journal. It is devoted to the publication of original scientific research articles dealing with various academic disciplines.Articles that may be of interest to a wide range of researchers are welcome, and not limited to those who work on specific research subjects."Academy Journal" has an open archive, according to which published articles are available immediately after publication, excluding embargoes.Expert reviewThere is one blind verification process in the journal. All articles will be initially evaluated by the editor for compliance with the journal. Manuscripts that are considered appropriate are then usually sent to at least two independent peer reviewers to assess the scientific quality of the article. The editor is responsible for the final decision on whether to accept or reject the article. The editor's decision is final.The main criterion used in assessing the manuscript submitted to the journal is: uniqueness or innovation in the work from the point of view of the methodology being developed and / or its application to a problem of particular importance in the public sector or service sector and / or the setting in which the efforts, for example, in the developing region of the world. That is, the very model / methodology, application and context of problems, at least one of them must be unique and important.Additional criteria considered in the consideration of the submitted document are its accuracy, organization / presentation (ie logical flow) and recording quality.

Theory and Practice of Quality Management in Lifelong Learning at a Public University

2018 ◽  
Vol 8 (2) ◽  
pp. 49-73
Author(s):  
Petr Adamec
Keyword(s):  
Lifelong Learning ◽  
Public University ◽  
Further Education ◽  
Point Of View ◽  
Theory And Practice ◽  
University Policy ◽  
Higher Education Act ◽  
Wide Range ◽  
Learning Programs ◽  
Education Act

The core issue of this paper is a quality in the lifelong learning. The aim of the contribution is to describe the area, level and dimensions of quality in a wide range of lifelong learning programs, respectively of further education, which are realized in the sense of § 60 and 60a of the Higher Education Act. The content of the paper also focuses on the theoretical and practical starting points of the quality phenomenon, both from the historical point of view and especially from the perspective of the current focus and concept of university policy in the European and Czech region. The paper also presents the results of a survey focusing on approaches to the quality assurance systems in the concept of components at selected public university.

scholarly journals Nitrile Synthesis with Aldoxime Dehydratases: A Biocatalytic Platform with Applications in Asymmetric Synthesis, Bulk Chemicals, and Biorefineries

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4466
Author(s):  
Pablo Domínguez de María
Keyword(s):  
Asymmetric Synthesis ◽  
Organic Solvents ◽  
Raw Materials ◽  
Aqueous Media ◽  
Industrial Processes ◽  
Polymer Chemistry ◽  
Fine Chemicals ◽  
Mild Conditions ◽  
Bulk Chemicals ◽  
Recent Developments

Nitriles comprise a broad group of chemicals that are currently being industrially produced and used in fine chemicals and pharmaceuticals, as well as in bulk applications, polymer chemistry, solvents, etc. Aldoxime dehydratases catalyze the cyanide-free synthesis of nitriles starting from aldoximes under mild conditions, holding potential to become sustainable alternatives for industrial processes. Different aldoxime dehydratases accept a broad range of aldoximes with impressive high substrate loadings of up to >1 Kg L−1 and can efficiently catalyze the reaction in aqueous media as well as in non-aqueous systems, such as organic solvents and solvent-free (neat substrates). This paper provides an overview of the recent developments in this field with emphasis on strategies that may be of relevance for industry and sustainability. When possible, potential links to biorefineries and to the use of biogenic raw materials are discussed.

scholarly journals Insights into the Antioxidant Mechanism of Newly Synthesized Benzoxazinic Nitrones: In Vitro and In Silico Studies with DPPH Model Radical

Antioxidants ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1224
Author(s):  
Stefania Marano ◽  
Cristina Minnelli ◽  
Lorenzo Ripani ◽  
Massimo Marcaccio ◽  
Emiliano Laudadio ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Epr Spectroscopy ◽  
Point Of View ◽  
Uv Spectrophotometry ◽  
Design And Synthesis ◽  
Antioxidant Mechanism ◽  
Primary Mechanism ◽  
In Silico Studies ◽  
Wide Range

Synthetic nitrone spin-traps are being explored as therapeutic agents for the treatment of a wide range of oxidative stress-related pathologies, including but not limited to stroke, cancer, cardiovascular, and neurodegenerative diseases. In this context, increasing efforts are currently being made to the design and synthesis of new nitrone-based compounds with enhanced efficacy. The most researched nitrones are surely the ones related to α-phenyl-tert-butylnitrone (PBN) and 5,5-dimethyl-1-pyrroline N-oxide (DMPO) derivatives, which have shown to possess potent biological activity in many experimental animal models. However, more recently, nitrones with a benzoxazinic structure (3-aryl-2H-benzo[1,4]oxazin-N-oxides) have been demonstrated to have superior antioxidant activity compared to PBN. In this study, two new benzoxazinic nitrones bearing an electron-withdrawing methoxycarbonyl group on the benzo moiety (in para and meta positions respect to the nitronyl function) were synthesized. Their in vitro antioxidant activity was evaluated by two cellular-based assays (inhibition of AAPH-induced human erythrocyte hemolysis and cell death in human retinal pigmented epithelium (ARPE-19) cells) and a chemical approach by means of the α,α-diphenyl-β-picrylhydrazyl (DPPH) scavenging assay, using both electron paramagnetic resonance (EPR) spectroscopy and UV spectrophotometry. A computational approach was also used to investigate their potential primary mechanism of antioxidant action, as well as to rationalize the effect of functionalization on the nitrones reactivity toward DPPH, chosen as model radical in this study. Further insights were also gathered by exploring the nitrone electrochemical properties via cyclic voltammetry and by studying their kinetic behavior by means of EPR spectroscopy. Results showed that the introduction of an electron-withdrawing group in the phenyl moiety in the para position significantly increased the antioxidant capacity of benzoxazinic nitrones both in cell and cell-free systems. From the mechanistic point of view, the calculated results closely matched the experimental findings, strongly suggesting that the H-atom transfer (HAT) is likely to be the primary mechanism in the DPPH quenching.

scholarly journals Photocatalytic three-component asymmetric sulfonylation via direct C(sp3)-H functionalization

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Shi Cao ◽  
Wei Hong ◽  
Ziqi Ye ◽  
Lei Gong
Keyword(s):  
Asymmetric Catalysis ◽  
Organic Synthesis ◽  
Photochemical Reaction ◽  
Low Cost ◽  
Bioactive Molecules ◽  
Atom Economy ◽  
Mild Conditions ◽  
Wide Range ◽  
Unsaturated Carbonyl Compound ◽  
Direct Functionalization

AbstractThe direct and selective C(sp3)-H functionalization of cycloalkanes and alkanes is a highly useful process in organic synthesis owing to the low-cost starting materials, the high step and atom economy. Its application to asymmetric catalysis, however, has been scarcely explored. Herein, we disclose our effort toward this goal by incorporation of dual asymmetric photocatalysis by a chiral nickel catalyst and a commercially available organophotocatalyst with a radical relay strategy through sulfur dioxide insertion. Such design leads to the development of three-component asymmetric sulfonylation involving direct functionalization of cycloalkanes, alkanes, toluene derivatives or ethers. The photochemical reaction of a C(sp3)-H precursor, a SO2 surrogate and a common α,β-unsaturated carbonyl compound proceeds smoothly under mild conditions, delivering a wide range of biologically interesting α-C chiral sulfones with high regio- and enantioselectivity (>50 examples, up to >50:1 rr and 95% ee). This method is applicable to late-stage functionalization of bioactive molecules, and provides an appealing access to enantioenriched compounds starting from the abundant hydrocarbon compounds.

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