scholarly journals A new electrocatalytic systems based on bisorbents from rice husk

Author(s):  
Bazarbai Serikbaev ◽  
Duisek Kamysbaev ◽  
Galina Arbuz ◽  
Dinara Alimbai ◽  
Akbayan Arin

The article studies the synthesis of carbon-based and amorphous silicon dioxide bisorbents. Sorption characteristics of new bases for producing modified systems to use them in electrocatalysis are presented. For preparation of SiO2/C baseas rice husk (RH) was chosen as the raw material. A series of experiments was performed to optimize parameters of the RH carbonization by varying temperature and time of the process. The material obtained from the RH thermal destruction products was modified by the heteropoly compound (NH4)3[Co3O6Mo6O18H6] · nH2O and thermally reduced by hydrogen. The registration of the voltammetric curves was carried out at pH = 6.22 in the background electrolyte of 0.1 M Na2SO4 and pH = 4.45 in 0.1 M KC8H5O4.The potential ranges were -1.2В – 1.2 V and -1.0 V – 0.2 respectively. The mechanism of the electrochemical processes on these materials has been studied. It is shown that the obtained composite electrode materials exhibit electrochemical activity in the investigated potential regions, and they are characterized by the stability of redox properties. The main ways of using the obtained composites are outlined.

Author(s):  
Duisek Kamysbaev ◽  
Bazarbai Serikbaev ◽  
Galina Arbuz

The article presents results of the synthesis of a new composite material modified with polyvalent metals. Rice husk was chosen as a raw material for obtaining a carrier – a bisorbent consisting of carbon and amorphous silicon oxide. The sorption material was obtained from the products of thermal decomposition of rice husks. Further it was modified with ammonium salts of molybdenum and tungsten: (NH4)6Mo7O24·4H2O and (NH4)2O·12WO3·5H2O in Mo/W ratios: 5/5 wt. %, 10/5 wt. % and reducted by heating in a stream of hydrogen. The registration of the voltammetric curves in the medium of 1-methyl-4-piperidone was carried out in various background electrolytes: 0.2 M Li2SO4, pH = 6.36 and 0.1 M KOH, pH = 13, 2,5·10–2 M K2HPO4 + 2,5·10–2 M NaH2PO4, pH = 6.86. Differential voltammetric curves were analyzed. The electrochemical activity of the obtained modified composites in the potential range from -1.2 V to 0.5 V was determinated. The mechanism of the proceeding electrochemical processes on these modified electrode materials has been studied. The possibility of further use of synthesized composite systems based on bisorbents from the rice husk for the electrochemical reduction of 1-methyl-4-piperidone was shown.


Author(s):  
N. A. Bulychev

In this paper, the plasma discharge in a high-pressure fluid stream in order to produce gaseous hydrogen was studied. Methods and equipment have been developed for the excitation of a plasma discharge in a stream of liquid medium. The fluid flow under excessive pressure is directed to a hydrodynamic emitter located at the reactor inlet where a supersonic two-phase vapor-liquid flow under reduced pressure is formed in the liquid due to the pressure drop and decrease in the flow enthalpy. Electrodes are located in the reactor where an electric field is created using an external power source (the strength of the field exceeds the breakdown threshold of this two-phase medium) leading to theinitiation of a low-temperature glow quasi-stationary plasma discharge.A theoretical estimation of the parameters of this type of discharge has been carried out. It is shown that the lowtemperature plasma initiated under the flow conditions of a liquid-phase medium in the discharge gap between the electrodes can effectively decompose the hydrogen-containing molecules of organic compounds in a liquid with the formation of gaseous products where the content of hydrogen is more than 90%. In the process simulation, theoretical calculations of the voltage and discharge current were also made which are in good agreement with the experimental data. The reaction unit used in the experiments was of a volume of 50 ml and reaction capacity appeared to be about 1.5 liters of hydrogen per minute when using a mixture of oxygen-containing organic compounds as a raw material. During their decomposition in plasma, solid-phase products are also formed in insignificant amounts: carbon nanoparticles and oxide nanoparticles of discharge electrode materials.


Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1233
Author(s):  
Yuchao Zhao ◽  
Nan Ye ◽  
Haiou Zhuo ◽  
Chaolong Wei ◽  
Weiwei Zhou ◽  
...  

Tungsten-copper (W–Cu) composites are widely used as electrical contact materials, resistance welding, electrical discharge machining (EDM), and plasma electrode materials due to their excellent arc erosion resistance, fusion welding resistance, high strength, and superior hardness. However, the traditional preparation methods pay little attention to the compactness and microstructural uniformity of W–Cu composites. Herein, W–Cu composite coatings are prepared by pulse electroplating using nano-W powder as raw material and the influence of forward-reverse duty cycle of pulse current on the structure and mechanical properties is systematically investigated. Moreover, the densification mechanism of the W–Cu composite coating is analyzed from the viewpoints of forward-pulse plating and reverse-pulse plating. At the current density (J) of 2 A/dm2, frequency (f) of 1500 Hz, forward duty cycle (df) of 40% and reverse duty cycle (dr) of 10%, the W–Cu composite coating rendered a uniform microstructure and compact structure, resulting in a hardness of 127 HV and electrical conductivity of 53.7 MS/m.


2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Yu Zheng ◽  
Xudong Luo ◽  
Jinlong Yang ◽  
Wenlong Huo ◽  
Chi Kang

A novel approach is used for fabricating steel slag foam ceramics based on the particle-stabilized foaming method. In this work, steel slag was used as the raw material and propyl gallate (PG) was used as the surface modifier. For the first time, steel slag ceramic foams were successfully fabricated based on particle-stabilized foams. The results show that the stability of the ceramic foams was closely related to the pH value and PG concentration. The porosity and compressive strength could be controlled by changing the solid loading of steel slag and sintering temperature. The porosity of steel slag foam ceramics ranged from 85.6% to 62.53%, and the compressive strength was from 1.74 MPa to 10.42 MPa. The thermal conductivity of steel slag foam ceramics was only 0.067 W (m·K)−1, which shows that it could be used as a thermal insulation material.


2014 ◽  
Vol 1010-1012 ◽  
pp. 1015-1019
Author(s):  
Ze Xin Yang ◽  
Lin Dong ◽  
Meng Wang ◽  
Huan Li

The main purpose of this article is to develop an environmentally friendly and economically effective process to produce silica from rice husk ash. Sodium silicate solution was prepared by the reaction of rice husk ash and sodium hydroxide solution, and then the sodium silicate solution was used as the raw material for the preparation of silica with sodium bicarbonate. During the reaction, the by-product can be passed into CO2 to prepare sodium bicarbonate what can be reutilized. Experimental route achieved resource recycling and environment-friendly, low energy consumption, zero emissions and so on. Meanwhile the microstructures of the silica powders were characterized by Transmission electron microscope (TEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR) and Thermo gravimetric/Differential thermal analyzer (TG-DTA).The purity of silicon was up to 99.43% and the particle size was 200-300nm.


2012 ◽  
Vol 454 ◽  
pp. 324-328
Author(s):  
Yan He ◽  
Ya Jing Liu ◽  
Yong Lin Cao ◽  
Li Xia Zhou

Infra-red absorption spectrometry, X-ray diffraction observations and characterization tests based on silicon molybdenum colorimetric method were used to investigate the optimal pH value controlling the stability of the silicic acid form. The experiment process was done by using sodium silicate as raw material. The results showed that the solution of silicate influenced the polymerization. The active silicic acid solution with a certain degree of polymerization was obtained by controlling the pH values.


PEDIATRICS ◽  
1973 ◽  
Vol 51 (6) ◽  
pp. 1016-1026
Author(s):  
Ralph D. Feigin ◽  
Kanneth S. Moss ◽  
Penelope G. Shackelford

The present study was designed to assess the stability of ampicillin, carbenicillin, clindamycin, kanamycin, cephalothin, methicillin, and penicillin in three parenteral hyperalimentation mixtures as reconstituted for delivery to the patient in the clinical setting. Stability at 4C, 25C, and 37C was tested in parenteral hyperalimentation mixtures containing either crystalline amino acids or a protein hydrolysate. In two series of experiments the stability at 4C, 25C, and 37C of ampicillin, cephalothin, and kanamycin also was assessed in Isolyte M (ISO M), Isolyte P (ISO P), Ringer's lactate (LR), 5% dextrose in water, (D5W), 10% dextrose in water (D1OW), dextrose in normal saline (D5S), and normal saline (NS) to which hydrocortisone or heparin had been added. All antibiotics retained their effectiveness at an acceptable level in the hyperalimentation solutions at 4C. At 25C and 37C, all antibiotics except clindamycin lost activity by 24 hours. Kanamycin was least stable in these solutions and ampicillin also lost a significant degree of antimicrobial activity. Addition of heparin or hydrocortisone imparted stability to ampicillin in the seven parenteral solutions although significant loss of activity was noted at 37C in D5W, D1OW, D5S, and LR. Most solutions containing heparin or hydrocortisone and cephalothin turned yellow by 24 hours. A precipitate appeared in solutions containing heparin and kanamycin but there was minimal loss of antimicrobial activity. Kanamycin was stable in all solutions containing hydrocortisone except in D5W and D10W at 37C.


Author(s):  
А.О. ЕВСЮКОВА

Согласно данным проекта Стратегии развития физической культуры и спорта в Российской Федерации до 2030 года, в 2008–2019 гг. численность систематически занимающегося физической культурой и спортом населения выросла в 2,5 раза. Это обусловливает необходимость создания инновационных продуктов для людей занимающихся спортом. Для определения перспектив создания продуктов специального назначения, в частности функциональных напитков для спортивного питания, проведен анализ патентов в этой области. Объектом анализа были 59 патентов, опубликованных с 1995 г. по май 2020 г. и занесенных в отечественную – ФИПС и международные – EAPATIS, USPTO, EPO, CISPATANT базы данных. Проанализированы следующие подклассы изобретений по актуализированной версии МПК: A23C, A23D, A23F, A23G, A23J, A23K, A23L, A61K, A61P, C12G. Результаты исследований представлены на рисунках в виде диаграмм. Установлено, что производство функциональных напитков для спортивного питания активно развивается. Российская Федерация имеет преимущество по количеству зарегистрированных патентов в этой области, но по объему производства продукции уступает зарубежным странам. Поскольку продукция агропромышленного комплекса России вполне удовлетворяет требованиям потребителей к натуральности сырьевого состава продукта, для обеспечения стабильности внутреннего рынка перспективно развитие отечественного производства функциональных напитков для спортивного питания. According to the draft strategy for the development of physical culture and sports in the Russian Federation until 2030, in 2008–2019, the number of people systematically engaged in physical culture and sports increased by 2,5 times. This makes it necessary to create innovative products for people involved in sports. To determine the prospects for creating special-purpose products, in particular functional beverages for sports nutrition, an analysis of patents in this area was conducted. 59 patents published from 1995 to may 2020 and included in the national – FIPS and international – EAPATIS, USPTO, EPO, CISPATANT databases were the object of analysis. Subclasses of inventions according to the updated version of the IPC A23C, A23D, A23F, A23G, A23J, A23K, A23L, A61K, A61P and C12G are analyzed. The results of the research are presented in figures in the form of diagrams. It is established that the production of functional beverages for sports nutrition is actively developing. The Russian Federation has an advantage in the number of registered patents in this area, but in terms of production volume it is inferior to foreign countries. Since the products of the Russian agro-industrial complex fully meet the requirements of consumers for the naturalness of the raw material composition of the product, the development of domestic production of functional beverages for sports nutrition is promising to ensure the stability of the domestic market.


Author(s):  
Lei Wang ◽  
Kathleen C Frisella ◽  
Pattarachai Srimuk ◽  
Oliver Janka ◽  
Guido Kickelbick ◽  
...  

Electrochemical processes enable fast lithium extraction, for example, from brines, with high energy efficiency and stability. Lithium iron phosphate (LiFePO4) and manganese oxide (λ-MnO2) have usually been employed as the...


2020 ◽  
Vol 20 (2) ◽  
Author(s):  
Ardhitya Alam Wiguna ◽  
Linda Ekadewi Widyatami

Doho Suwar-Suwir is a Micro Small Medium Enterprises (UMKM) processing Fermented Cassava (Tape Singkong) to become a processed food in Jember, which is Suwar-Suwir. To maintain the stability of production process, needs a control for the stock management towards the raw material at Doho Suwar-Suwir UMKM. The raw material inventory management at Doho Suwar-Suwir UMKM is about fermented cassava raw material inventory which then are processed to become the typical food of Jember Regency, which is Suwar-Suwir. The goal of this research were to analyze the fermented cassava raw material inventory quantity and to analyze the safety stock quantity at Doho Suwar-Suwir UMKM. The method used in this research was stock management calculation or Economical Order Quantity (EOQ) where the result of this research was the quantity of fermented cassava raw material  needed using Economical Order Quantity (EOQ) method at Doho Suwar-Suwir business was 60,6 kg and the number of the safety stock which must exist was 5,5 kg.


Sign in / Sign up

Export Citation Format

Share Document