scholarly journals Hydrogen from Renewables: A Case Study of Glycerol Reforming

Catalysts ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 722 ◽  
Author(s):  
Andrea Fasolini ◽  
Daniele Cespi ◽  
Tommaso Tabanelli ◽  
Raffaele Cucciniello ◽  
Fabrizio Cavani
Keyword(s):  
Supported Catalysts ◽  
Biomass Conversion ◽  
Academic Research ◽  
Experimental Studies ◽  
Short Review ◽  
Raw Material ◽  
Advanced Materials ◽  
Industrial Community ◽  
Interesting Candidate ◽  
Glycerol Reforming

Biomass is an interesting candidate raw material for the production of renewable hydrogen. The conversion of biomass into hydrogen can be achieved by several processes. In particular, this short review focuses on the recent advances in glycerol reforming to hydrogen, highlighting the development of new and active catalysts, the optimization of reaction conditions, and the use of non-innocent supports as advanced materials for supported catalysts. Different processes for hydrogen production from glycerol, especially aqueous phase reforming (APR) and steam reforming (SR), are described in brief. Thermodynamic analyses, which enable comparison with experimental studies, are also considered. In addition, research advances in terms of life cycle perspective applied to support R&D activities in the synthesis of renewable H2 from biomass are presented. Lastly, also featured is an evaluation of the studies published, as evidence of the increased interest of both academic research and the industrial community in biomass conversion to energy sources.

scholarly journals Theoretical investigation of mollusk shells: Energy landscape exploration of CaCo3 polymorphs and element substitution: A short review

2021 ◽  
Vol 10 (1) ◽  
pp. 73-80
Author(s):  
Tamara Škundrić ◽  
Dejan Zagorac ◽  
Aleksandra Zarubica ◽  
Branko Matović
Keyword(s):  
Calcium Carbonate ◽  
Experimental Studies ◽  
Short Review ◽  
Advanced Materials ◽  
Free Energies ◽  
Calculation Methods ◽  
Ambient Conditions ◽  
Mollusk Shells ◽  
Crystalline Forms ◽  
Calcium Carbonate Polymorphs

Due to the remarkable properties achieved under ambient conditions and with quite limited components, mollusk shells are very appealing natural bio-composites used as inspiration for new advanced materials. Calcium carbonate which is among the most widespread biominerals is used by mollusks as a building material that constitutes 95-99% of their shells. Within the investigation of calcium carbonate polymorphs present in the shells, diverse theoretical and experimental studies were performed, however, further research of these crystalline forms is required. There are very little researches on the energy landscapes of biogenic calcium carbonate which can provide us information about the free energies of already known as well as newly discovered plausible structures. To investigate the structural, mechanical, elastic, or vibrational properties and to predict new possible structures of biogenic calcium carbonate, different calculation methods could be employed. Some of these studies are presented and discussed in this paper.

Applications of Bentonite to Soil Decontamination

2018 ◽  
Vol 69 (7) ◽  
pp. 1695-1698
Author(s):  
Marin Rusanescu ◽  
Carmen Otilia Rusanescu ◽  
Gheorghe Voicu ◽  
Mihaela Begea
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Laboratory Experiments ◽  
Experimental Studies ◽  
Heavy Metal Concentration ◽  
Polluted Soil ◽  
Raw Material ◽  
Soil Decontamination ◽  
Metal Retention ◽  
Removal Of Heavy Metals

A calcium bentonite from Orasu Nou deposit (Satu Mare Romania) was used as raw material. We have conducted laboratory experiments to determine the influence of bentonite on the degree of heavy metal retention. It has been observed that the rate of retention increases as the heavy metal concentration decreases. Experimental studies have been carried out on metal retention ( Zn) in bentonite. In this paper, we realized laboratory experiments for determining the influence of metal (Zn) on the growth and development of two types of plants (Pelargonium domesticum and Kalanchoe) and the effect of bentonite on the absorption of pollutants. These flowers were planted in unpolluted soil, in heavy metal polluted soil and in heavy metal polluted soil to which bentonite was added to observe the positive effect of bentonite. It has been noticed that the flowers planted in unpolluted soil and polluted with heavy metals to which bentonite has been added, the flowers have flourished, the leaves are still green and the plants whose soils have been polluted with heavy metals began to dry after 6 days, three weeks have yellowish leaves and flowers have dried. Experiments have demonstrated the essential role of bentonite for the removal of heavy metals polluted soil.

A preliminary systematic review and meta-analysis on the effects of heart rate variability biofeedback on heart rate variability and respiration of athletes

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Jeffrey Cayaban Pagaduan ◽  
Yung-Sheng Chen ◽  
James William Fell ◽  
Sam Shi Xuan Wu
Keyword(s):  
Systematic Review ◽  
Heart Rate ◽  
Heart Rate Variability ◽  
Web Of Science ◽  
Meta Analysis ◽  
Academic Research ◽  
Experimental Studies ◽  
Quantitative Review ◽  
Heart Rate Variability Biofeedback ◽  
Randomized Control

Abstract To date, there is no quantitative review examining the influence of heart rate variability biofeedback (HRV BFB) on the athlete population. Such an undertaking may provide valuable information on the autonomic and respiration responses of athletes when performing HRV BFB. Thus, purpose of this preliminary systematic review and meta-analysis on the effects of HRV BFB on HRV and respiration of athletes. Searches of Springerlink, SportDiscus, Web of Science, PROQUEST Academic Research Library, Google Scholar, and ScienceDirect were conducted for studies that met the following criteria: (1) experimental studies involving athletes that underwent randomized control trial; (2) availability of HRV BFB as a treatment compared with a control (CON)/placebo (PLA); (3) any pre and post HRV variable and/or breathing frequency as dependent variable/s; and, (4) peer-reviewed articles written in English. Four out of 660 studies involving 115 athletes (25 females and 90 males) ages 16–30 years old were assessed in this review. Preliminary findings suggest the promising ability of HRV BFB to improve respiratory mechanics in athlete population. More work is needed to determine the autonomic modulatory effect of HRV BFB in athletes.

Biocatalysis and biomass conversion: enabling a circular economy

2020 ◽  
Vol 378 (2176) ◽  
pp. 20190274 ◽  
Author(s):  
Roger A. Sheldon
Keyword(s):  
Circular Economy ◽  
Biomass Conversion ◽  
Raw Material ◽  
Liquid Fuels ◽  
Waste Biomass ◽  
Renewable Biomass ◽  
Precious Metal Catalysts ◽  
Mitigate Climate Change ◽  
Forestry Residues ◽  
The Right

This paper is based on a lecture presented to the Royal Society in London on 24 June 2019. Two of the grand societal and technological challenges of the twenty-first century are the ‘greening' of chemicals manufacture and the ongoing transition to a sustainable, carbon neutral economy based on renewable biomass as the raw material, a so-called bio-based economy. These challenges are motivated by the need to eliminate environmental degradation and mitigate climate change. In a bio-based economy, ideally waste biomass, particularly agricultural and forestry residues and food supply chain waste, are converted to liquid fuels, commodity chemicals and biopolymers using clean, catalytic processes. Biocatalysis has the right credentials to achieve this goal. Enzymes are biocompatible, biodegradable and essentially non-hazardous. Additionally, they are derived from inexpensive renewable resources which are readily available and not subject to the large price fluctuations which undermine the long-term commercial viability of scarce precious metal catalysts. Thanks to spectacular advances in molecular biology the landscape of biocatalysis has dramatically changed in the last two decades. Developments in (meta)genomics in combination with ‘big data’ analysis have revolutionized new enzyme discovery and developments in protein engineering by directed evolution have enabled dramatic improvements in their performance. These developments have their confluence in the bio-based circular economy. This article is part of a discussion meeting issue ‘Science to enable the circular economy'.

Studying the Effect of some Factors on the Stress-Strain Behavior of the Rostov Region Limestones in the Course of their Production and Use

2021 ◽  
Vol 1022 ◽  
pp. 80-86
Author(s):  
Mikhail G. Kholodnyak ◽  
Sergey A. Stelmakh ◽  
Evgeniy M. Shcherban ◽  
Mukhuma P. Nazhuev
Keyword(s):  
Construction Material ◽  
Experimental Studies ◽  
Raw Material ◽  
Material Base ◽  
Strain Behavior ◽  
Current State ◽  
Rostov Region ◽  
Literary Sources ◽  
Crushed Granite ◽  
Strain Stress

The paper considers the current state of the mineral raw material base and the construction material market of the Rostov Region. The effect of various factors on the strain-stress behavior of local limestones has been investigated. The scientific and technical literary sources devoted to the processes of rock failure under various loads have been analyzed. The experimental studies have shown that the tested samples of limestone with a high content of cuboidal grains have characteristics comparable to those of the crushed granite stone. It has been concluded that the use of the Rostov Region limestones in the construction industry is competitive and feasible, provided the proper implementation of the engineering measures proposed in their production.

Chemistry of the Gasification of Carbonaceous Raw Material

2021 ◽  
Vol 1045 ◽  
pp. 67-78
Author(s):  
Pavlo Saik ◽  
Roman Dychkovskyi ◽  
Vasyl Lozynskyi ◽  
Volodymyr Falshtynskyi ◽  
Edgar Caseres Cabana ◽  
...  
Keyword(s):  
Gas Flow ◽  
Experimental Studies ◽  
Reaction Channel ◽  
Raw Material ◽  
Gas Generator ◽  
Equal Concentration ◽  
Gasification Process ◽  
Gasification Rate ◽  
Gasification Products ◽  
Gas Flow Velocity

The paper represents the studies of the process of carbonaceous raw material gasification. The initial material is represented by bituminous coal of grade H with the carbon (C) content of 79.2-85.3 %. Experimental studies have been used to substantiate the parameters of combustible generator gases (СО, Н2, СН4) output depending on the temperature of a reduction zone of the reaction channel and gas flow velocity along its length. It has been identified that the volume of the raw material input to be used for gasification process changes in direct proportion depending on the amount of burnt-out carbon and blow velocity. The gasification is intensified in terms of equal concentration of oxygen and carbon in the reaction channel of an underground gas generator. The gasification rate is stipulated by the intensity of chemical reactions, which depend immediately on the modes of blow mixture supply. Moreover, they depend directly on the intensity of oxygen supply to the coal mass and removal of the gasification products.

scholarly journals ДОСЛІДЖЕННЯ ГІГІЄНІЧНИХ ВЛАСТИВОСТЕЙ МАТЕРІАЛІВ НАТІЛЬНОЇ ЛІКАРНЯНОЇ БІЛИЗНИ

2020 ◽  
Vol 140 (6) ◽  
pp. 38-47
Author(s):  
І. О. Іванов ◽  
Н. П. Супрун ◽  
Ю. О. Ващенко
Keyword(s):  
Comparative Analysis ◽  
Materials Science ◽  
Experimental Studies ◽  
Operating Conditions ◽  
Raw Material ◽  
Experimental Investigations ◽  
Textile Materials ◽  
Composition And Structure ◽  
Innovative Materials ◽  
Basic Functions

Investigation of the influence of the peculiarities of raw material composition and structure of traditional and innovative linen textile materials on their hygienic properties. Theoretical and experimental investigations are based on the main positions of textile materials science. In experimental studies, modern standardized methods for determining the hygienic properties of textile materials were used, as well as techniques specially developed taking into account the peculiarities of the operating conditions of underwear. The peculiarities of the operating conditions and the basic functions of hospital underwear were determined. The comparative analysis of hygienic properties of traditional and modern fabrics for underwear was carried out. Using the standardized and the developed methods, adapted to the peculiarities of the conditions of use of the products, the indicators characterizing the processes of water absorption of the materials were experimentally determined. On the basis of the obtained values of quality indicators, a comprehensive assessment of the ability of materials to transfer moisture and air, with the calculation of the arithmetic complex quality index was done. This allowed to determine the material that is optimal in properties, which provides thermophysiological comfort when operating hospital underwear. Using the developed methods, which take into account the specifics of the operating conditions, a comparative analysis of the hygienic properties of traditional and innovative materials for underwear was carried out. A new range of textile materials for underwear has been proposed, taking into account the peculiarities of the operational situation of consumption.

Five-Membered Hetarene N-Oxides: Recent Advances in Synthesis and Reactivity

Synthesis ◽  
2021 ◽  
Author(s):  
Leonid Fershtat ◽  
Fedor Teslenko
Keyword(s):  
Transition Metal ◽  
Medicinal Chemistry ◽  
Materials Science ◽  
State Of The Art ◽  
Short Review ◽  
Advanced Materials ◽  
Metal Free ◽  
Recent Advances ◽  
Application Potential ◽  
Metal Catalyzed

Five-membered heterocyclic N-oxides attracted special attention due to their strong application potential in medicinal chemistry and advanced materials science. In this regard, novel methods for their synthesis and functionalization are constantly required. In this short review, recent state-of-the-art achievements in the chemistry of isoxazoline N-oxides, 1,2,3-triazole 1-oxides and 1,2,5-oxadiazole 2-oxides are briefly summarized. Main routes to transition-metal-catalyzed and metal-free functionalization protocols along with mechanistic considerations are outlined. Transformation patterns of the hetarene N-oxide rings as precursors to other nitrogen heterocyclic systems are also presented.

Non-Wood Lignocellulosic Composites

2014 ◽  
pp. 281-319 ◽  
Author(s):  
Marius C. Barbu ◽  
Roman Reh ◽  
Ayfer Dönmez Çavdar
Keyword(s):  
Mechanical Properties ◽  
Composite Materials ◽  
Experimental Studies ◽  
Raw Material ◽  
Synthetic Fiber ◽  
Plant Fibers ◽  
Labor Conditions ◽  
Appropriate Treatment ◽  
Manufacturing Technologies ◽  
Cellulose Materials

It would seem that with appropriate treatment almost any agricultural residue may be used as a suitable raw material for the wood-based panels like particle- and fiberboard production. The literature on wood-ligno-cellulose plant composite boards highlights steady interest for the design of new structures and technologies towards products for special applications with higher physical-mechanical properties at relatively low prices. Experimental studies have revealed particular aspects related to the structural composition of ligno-cellulose materials, such as the ratio between the different composing elements, their compatibility, and the types and characteristics of the used resins. Various technologies have been developed for designing and processing composite materials by pressing, extrusion, airflow forming, dry, half-dry, and wet processes, including thermal, chemical, thermo-chemical, thermo-chemo-mechanical treatments, etc. Researchers have undertaken to determine the manufacturing parameters and the physical-mechanical properties of the composite boards and to compare them with the standard PB, MDF, HB, SB made from single-raw material (wood). A great emphasis is placed on the processability of the ligno-cellulose composite boards by classical methods, by modified manufacturing processes, on the types of tools and processing equipment, the automation of the manufacturing technologies, the specific labor conditions, etc. The combinations of wood and plant fibers are successful, since there is obvious compatibility between the macro- and microscopic structures, their chemical composition, and the relatively low manufacturing costs and high performances, as compared to synthetic fiber-based composite materials.

scholarly journals A Short Review on Ni Based Catalysts and Related Engineering Issues for Methane Steam Reforming

Catalysts ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 352 ◽  
Author(s):  
Eugenio Meloni ◽  
Marco Martino ◽  
Vincenzo Palma
Keyword(s):  
Steam Reforming ◽  
Large Scale ◽  
Short Review ◽  
Raw Material ◽  
Methane Steam Reforming ◽  
Thermal Exchange ◽  
Structured Catalysts ◽  
Methane Steam ◽  
Load Fluctuation ◽  
Hydrogen Station

Hydrogen is an important raw material in chemical industries, and the steam reforming of light hydrocarbons (such as methane) is the most used process for its production. In this process, the use of a catalyst is mandatory and, if compared to precious metal-based catalysts, Ni-based catalysts assure an acceptable high activity and a lower cost. The aim of a distributed hydrogen production, for example, through an on-site type hydrogen station, is only reachable if a novel reforming system is developed, with some unique properties that are not present in the large-scale reforming system. These properties include, among the others, (i) daily startup and shutdown (DSS) operation ability, (ii) rapid response to load fluctuation, (iii) compactness of device, and (iv) excellent thermal exchange. In this sense, the catalyst has an important role. There is vast amount of information in the literature regarding the performance of catalysts in methane steam reforming. In this short review, an overview on the most recent advances in Ni based catalysts for methane steam reforming is given, also regarding the use of innovative structured catalysts.

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