scholarly journals Brazilian tungsten panorama (w) between 2008 and 2014

2018 ◽  
pp. 22-29
Author(s):  
Yara Lorrane Souza Barros ◽  
Franciolli da Silva Dantas Araújo ◽  
Amanda Alves Fecury ◽  
Euzébio Oliveira ◽  
Carla Viana Dendasck ◽  
...  
Keyword(s):  
Melting Point ◽  
Computer Network ◽  
Raw Materials ◽  
Specific Weight ◽  
Chemical Substance ◽  
Network Data ◽  
Sharp Drop ◽  
Microsoft Corporation ◽  
Mineral Production ◽  
Constant Characteristics

Minerals are natural chemicals, which have an ordered internal structure, and certain constant characteristics that allow them to be identified as mineral. Tungsten (W) is a chemical substance that has a melting point of 3,419°C, and a specific weight of 19.3g/cm3… There are about 20 minerals that contain tungsten in its chemical composition, with scheelite and volframite being the main ones. The data were taken from the National Department of Mineral Production – DNPM (http://www.dnpm.gov.br/). The data was compiled within the Excel application, a component of the Microsoft Corporation Office suite. The bibliographic research was carried out in scientific articles found in the worldwide computer network. Data show that between 2008 and 2010 there was a decline in tungsten production in the form of contained mineral and concentrate. From 2011 on, production grew. Brazil exported almost four times what it imported from tungsten in the researchperiod. Between 2008 and 2012 there was an increase in the apparent consumption of tungsten. In 2013 and 2014 there was a sharp drop in relation to other years. The Brazilian tungsten picture showed difficulties, but continued to grow, bringing research that can improve the consumption and production of raw materials in the national territory.

Synthesis and Characterization of Super-Molecular Ionic Liquids

2011 ◽  
Vol 197-198 ◽  
pp. 906-910
Author(s):  
Hui Ru Liu ◽  
Li Qiang Lv ◽  
Xing Chen Zhang
Keyword(s):  
Ionic Liquid ◽  
Ionic Liquids ◽  
Melting Point ◽  
Quantum Chemical ◽  
Organic Molecules ◽  
Raw Materials ◽  
Ammonium Thiocyanate ◽  
Molar Ratio ◽  
Molecular Ion

This study concerned a novel super-molecular ionic liquid synthesized by ammonium thiocyanate and caprolactam. The physical characters such as melting point and electric conductivity were investigated. Results showed that the melting point is -12.2°C at the molar ratio of 3:1 (caprolactam/ammonium thiocyanate), which is much lower than raw materials. The electric conductivities of synthesized ionic liquids were close to that of imidazole ILs. The structure of ionic liquid was characterized by IR,1HNMR and quantum chemical calculations. It was shown that the NH4+cation connected with caprolactam organic molecules by hydrogen bonds, leading to the forming of a super-molecular ion. The electrostatic attraction of super-molecular ion with anion was decreased because of the larger volume of super-molecular ion than original cation, thus the melting point decreased. The key properties that distinguish super-molecular ionic liquid from other ILs were the presence of supermolecular ion, which can be used to build up a hydrogen-bonded network. This type ion liquid was named as super-molecular ion liquid.

ECONOMIC PREREQUISITES FOR THE FORMATION OF OPTIMAL SUGAR MILLS RAW ZONES OF THE OREL REGION

2020 ◽  
Vol 5 (86) ◽  
pp. 123-129
Author(s):  
E.Yu. Kalinicheva ◽  
◽  
M.N. Uvarova ◽  
L.N. Zhilina ◽  
◽  
...  
Keyword(s):  
Sugar Beet ◽  
Production Efficiency ◽  
Agricultural Sector ◽  
Raw Materials ◽  
Sugar Content ◽  
Specific Weight ◽  
Raw Material ◽  
Sugar Beets ◽  
Sugar Mills ◽  
Sown Area

The article justified the necessity of developing a strategy for the improvement of the sugar beet subcomplex of the region on the base of the determination of the close relationship between beet-growing farms, enterprises engaged in the delivery, processing and sale of manufactured products. According to the authors, the optimization of the raw material zone should include the principle of maximum loading of sugar mills, taking into account the raw materials produced in the region, optimizing transport costs for its delivery. The analysis of the sown area, productivity and gross yield of sugar beets gives us the idea that the region takes the tenth place among the largest producers of sugar beets. The yield and gross yield in 2019 in agricultural enterprises amounted to 459.6 centner / ha, 2231.9 thousand centner (an increase of 13.6% and 9.4% compared to the level of 2018).For P(F)E, the average increase is 40%, which corresponds to 481 centner / ha, 18.3 thousand tons. The average sugar content of beets during acceptance and processing ranges from 17.96 to 18.3%, the sugar yield is 15.63%, the sugar content in molasses is 1.68%, and the average daily productivity is 16.11 thousand ton / day, loss in production is 1.27%. The authors found that the production efficiency of the sugar beet industry is directly connected with the growth of labor productivity, the introduction of modern technologies, cost reduction, and thus, each farm has the opportunity to get additional profit. One of the main problems in the agricultural sector of the economy is the use of available resources to obtain the largest number of products. In our opinion, the production efficiency of sugar mills is closely interconnected with the constructed logistics routes for the transportation of raw materials with the exception of repeated shipments, the proportion of sugar beets in the sown area, and the reliability of suppliers. In our opinion, the efficiency of sugar mills production is in close connection with the built of the logistic routes for transportation of raw materials with the exception of repeated transportation, the specific weight of sugar beet in the structure of the sown area and the reliability ensuring of suppliers. The problem of the effective development of the sugar industry is relevant and priority in solving regional policies, the implementation of which will not only eliminate the emerging imbalances and reduce imports, but also support the domestic producer.

A Study of Corrosion Inhibition of Carbon Steel in Hydrochloric Acid Using BIMGCS12-3

2012 ◽  
Vol 427 ◽  
pp. 3-6 ◽  
Author(s):  
Yong Ming Sun ◽  
Hong Ling Chen
Keyword(s):  
Melting Point ◽  
Carbon Steel ◽  
Hydrochloric Acid ◽  
Corrosion Inhibition ◽  
Elemental Analysis ◽  
Inhibition Efficiency ◽  
Raw Materials ◽  
Ammonium Bromide ◽  
Target Compound ◽  
H Nmr

Gemini benzimidazole cationic surfactant, propanediyl-α, ω-bis-(N-dodecyl benzimidazole ammonium bromide), referred as BIMGCS12-3, was synthesized from the raw materials of benzimidazole, dodecane bromide and dibromopropane. The structure of the target compound was confirmed by1H NMR, elemental analysis and melting point measurements. Its surface properties were determined and corrosion inhibition of carbon steel in 1M HCl was investigated by gravimetric measurements. BIMGCS12-3 exhibited excellent protection for carbon steel in the low concentration 20mg L-1and the inhibition efficiency for corrosion decreased with increment of temperature.

scholarly journals CHROMATOGRAPHIC ANALYSIS OF THE EFFECT OF CATALYST QUANTITIES ON THE HYDROGENIZATION PROCESS

2020 ◽  
Vol 2020 (3) ◽  
pp. 72-75
Keyword(s):  
Melting Point ◽  
Iodine Number ◽  
Chromatographic Analysis ◽  
Food Industry ◽  
Raw Materials ◽  
Cottonseed Oil ◽  
Hydrogenated Oil ◽  
Main Components

Oil and fat industry is one of the important sectors of the food industry. Salomas (Hydrogenated oil) for food and technical purposes are the main components of margarine products, toilet, household soaps, various technological lubricants, cosmetic creams and can be used as valuable chemical raw materials. Objective: ox work is to study the effect of the amount of catalyst on the hydrogenation of cottonseed oil by chromatographic analysis of the resulting salomas. It is confirmed that an increase in the amount of the catalyst from 0.05 to 0.4% percent increases the melting point of salomas and reduces the iodine number, which confirms the known pattern of hydrogenation. Studies on the hydrogenation of cottonseed oil with various amounts of N-820 catalyst have established the possibility of reducing the content of transisomers of fats to 30.1%, increasing the melting point from 28.2 to 43.2 degree C and hardness to 500 g/cm.

English Sociological Terminology Based On Functional Equivalence Theory

2021 ◽  
Vol 7 (5) ◽  
pp. 4818-4828
Author(s):  
Cuiping Xu
Keyword(s):  
Computer Technology ◽  
Statistical Study ◽  
Computer Network ◽  
Functional Equivalence ◽  
Network Data ◽  
Automatic Construction ◽  
Party Building ◽  
Good Classification ◽  
Equivalence Theory ◽  
Knowledge Ontology

Objectives: In the practice of translating English, there are often situations that may lead to missing words. In this case, a computer technology is needed to improve the translation studies of sociological terms in English. This time, based on the characteristics of Internet network data, intelligent robot information is extracted. Methods: According to the knowledge ontology constructed this time, based on the functional equivalence theory, a method based on the automatic construction of the ontology library in the party building domain is proposed. Results: In order to verify the proposed method algorithm, the example study of some sociological terms conceptual terms above the interactive encyclopedia is studied by the ontology created by encyclopedia resources, such as father/sub-relationship, class and instance relationship and attribute relationship, and a total of 72474 relationships are obtained through the final statistical study. Conclusion: From the overall analysis, it can be seen that the sociological terminology research of English computer network based on functional equivalence theory can achieve a good classification effect.

scholarly journals Biodegradable Oligoesters of ε-Caprolactone and 5-Hydroxymethyl-2-Furancarboxylic Acid Synthesized by Immobilized Lipases

Polymers ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1402 ◽  
Author(s):  
Todea ◽  
Bîtcan ◽  
Aparaschivei ◽  
Păușescu ◽  
Badea ◽  
...  
Keyword(s):  
Melting Point ◽  
Raw Materials ◽  
Polymeric Chain ◽  
Chemical Route ◽  
Renewable Raw Materials ◽  
Immobilized Lipases ◽  
Polymeric Compounds ◽  
Ft Ir ◽  
Candida Antarctica B ◽  
Heterocyclic Structure

Following the latest developments, bio-based polyesters, obtained from renewable raw materials, mainly carbohydrates, can be competitive for the fossil-based equivalents in various industries. In particular, the furan containing monomers are valuable alternatives for the synthesis of various new biomaterials, applicable in food additive, pharmaceutical and medical field. The utilization of lipases as biocatalysts for the synthesis of such polymeric compounds can overcome the disadvantages of high temperatures and metal catalysts, used by the chemical route. In this work, the enzymatic synthesis of new copolymers of ε-caprolactone and 5-hydroxymethyl-2-furancarboxylic acid has been investigated, using commercially available immobilized lipases from Candida antarctica B. The reactions were carried out in solvent-less systems, at temperatures up to 80 °C. The structural analysis by MALDI TOF-MS, NMR, and FT-IR spectroscopy confirmed the formation of cyclic and linear oligoesters, with maximal polymerization degree of 24 and narrow molecular weight distribution (dispersity about 1.1). The operational stability of the biocatalyst was explored during several reuses, while thermal analysis (TG and DSC) indicated a lower thermal stability and higher melting point of the new products, compared to the poly(ε-caprolactone) homopolymer. The presence of the heterocyclic structure in the polymeric chain has promoted both the lipase-catalyzed degradation and the microbial degradation. Although, poly(ε-caprolactone) is a valuable biocompatible polymer with important therapeutic applications, some drawbacks such as low hydrophilicity, low melting point, and relatively slow biodegradability impeded its extensive utilization. In this regard the newly synthesized furan-based oligoesters could represent a “green” improvement route.

Thermoplastic Polyurethane (TPU) Honeycomb Air Cushion Combined with Polylactic Acid (PLA) Nonwoven Fabric for Impact Protection

2008 ◽  
Vol 55-57 ◽  
pp. 401-404 ◽  
Author(s):  
Cho Hsun Lee ◽  
Ching Wen Lou ◽  
Wen Hao Hsing ◽  
I.J. Tsai ◽  
Jia Horng Lin
Keyword(s):  
Melting Point ◽  
Polylactic Acid ◽  
Sandwich Structure ◽  
Raw Materials ◽  
Thermoplastic Polyurethane ◽  
Impact Resistance ◽  
Nonwoven Fabric ◽  
Honeycomb Structures ◽  
Air Cushion ◽  
Impact Protection

Honeycomb structures are widely used in various engineering fields, including construction, the auto industry, packaging, the aerospace industry, medicine, and sports. The hexagon cells generate excellent structures and reduce material waste. Honeycomb structures have very good mechanical properties and are low cost. Nonwoven fabric is widely used in many applications because the manufacturing process for nonwoven fabric is easy and fast. In this study, Polylactic Acid (PLA) nonwoven fabric and Thermoplastic Polyurethane (TPU) honeycomb air cushion (TPU-HAC) materials were combined in a sandwich structure for impact protection. The PLA fibers and low-melting-point PLA fibers were used as raw materials to create PLA nonwoven fabric. The PLA fibers and low-melting-point PLA fibers were mixed at weight ratios of (10%, 20%, 30%, 40%, 50%). The mixed fibers were processed using needle punching and thermal bonding to create PLA nonwoven fabric. Additionally, the TPU-HACs were layered to generate various thicknesses (2/8/10 mm, 4/6/10 mm, 6/4/10 mm, 8/2/10 mm). The layered TPU-HAC materials was clamped between two PLA nonwoven fabrics to form a sandwich structure. Impact resistance was assessed using a falling- weight impact-resistance machine. Experimental findings indicate that impact resistance of the sandwich structure of the TPU-HAC materials improved when thin TPU-HAC material was placed on the thick TPU-HAC material. This study demonstrates that the sandwich structure of TPU-HAC materials as excellent impact absorption.

The Simulation Analysis of Network Video Teaching Flow in School

2014 ◽  
Vol 687-691 ◽  
pp. 2792-2795
Author(s):  
Jun Ru Li ◽  
Wen Rui Li
Keyword(s):  
Carrying Capacity ◽  
Computer Network ◽  
Simulation Analysis ◽  
Teaching Experience ◽  
Teaching Quality ◽  
Sharp Drop ◽  
Teaching System ◽  
Optimization Program ◽  
School Teaching ◽  
School Network

With the development and popularization of computer, network video teaching is the new medium of school teaching. But because the scale of network video teaching system and broadband carrying capacity are limited, network video is hard to satisfy the massive need in school, thereby it could lead to sharp drop in network video teaching quality. Through establishing a simulation platform based on OPNET, the article analyse the video teaching system under network construction of school network; compare and discuss a optimization program of network current-limiting; and make a simulation test on optimization program of network cureent-limiting. The result show that through selecting right optimization program of network cureent-limiting, we can make s big promotion in system carrying capacity, and enhance the user’s video-teaching experience.

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