Chemical Industry最新文献_第8页

Micromechanical analysis of fatigue and crack growth in carbon-fiber epoxy composites based on mechanical testing 基于力学试验的碳纤维环氧复合材料疲劳与裂纹扩展细观力学分析

Chemical Industry Pub Date : 2020-09-01 DOI: 10.2298/hemind200615022j

A. Jelić, M. Sekulić, M. Stamenović, Vukašin Ugrinović, S. Putic

引用次数: 0

Treatment of black copper with the use of iron scrap - part I 废铁处理黑铜。第1部分

Chemical Industry Pub Date : 2020-09-01 DOI: 10.2298/hemind200424020t

N. Toro, K. Pérez, M. Saldaña, E. Salinas-Rodríguez, Pía C. Hernández

{"title":"Treatment of black copper with the use of iron scrap - part I","authors":"N. Toro, K. Pérez, M. Saldaña, E. Salinas-Rodríguez, Pía C. Hernández","doi":"10.2298/hemind200424020t","DOIUrl":"https://doi.org/10.2298/hemind200424020t","url":null,"abstract":"Currently, there is a large amount of mineral resources not being exploited in large copper minings, a clear example are black copper minerals. These resources are generally not incorpo-rated into the extraction circuits or are not treated, either in stocks, leach pads, or debris. These exotic minerals have considerable amounts of Cu and Mn, which are commercially very attractive. They are refractory to conventional leaching processes, therefore, the use of reducing agents is necessary for treatment of these minerals in order to dissolve the present MnO2, which in turn allows Cu extraction. In this research, iron scrap Fe0 was used as a reducing agent for the dissolution of Mn from a black copper mineral in an acidic medium and compared to previous studies of the use of Fe2+ under the same conditions. In addition, the effects of a pretreatment process (agglomeration and curing) by adding NaCl are investigated in order to favor the reduction of MnO2. Finally, it was discovered that there is a higher kinetics of dissolution of Mn when working with Fe0 in short periods of time, although similar extraction efficiencies are obtained after prolonged times. The pretreatment process by adding NaCl resulted in increased Mn extraction in short periods of time (30 min). At applying high concentrations of the reducing agent, the effect of particle size on the dissolution rate of MnO2 was shown to be insignificant.","PeriodicalId":9933,"journal":{"name":"Chemical Industry","volume":"81 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77133732","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 7

Fighting fake science: The key role of scientists 打击伪科学:科学家的关键作用

Chemical Industry Pub Date : 2020-09-01 DOI: 10.2298/hemind20082924o

B. Obradovic, Ana Barcus

引用次数: 0

A novel kinetic cholinesterase-inhibition based method for quantification of biperiden in pharmaceutical preparations 一种新的动态胆碱酯酶抑制方法定量药物制剂中双藤碱

Chemical Industry Pub Date : 2020-09-01 DOI: 10.2298/hemind200413021d

V. Djurić, V. Mitić, N. Deletic, M. Ilic, B. Ćirković, V. Stankov-Jovanović

{"title":"A novel kinetic cholinesterase-inhibition based method for quantification of biperiden in pharmaceutical preparations","authors":"V. Djurić, V. Mitić, N. Deletic, M. Ilic, B. Ćirković, V. Stankov-Jovanović","doi":"10.2298/hemind200413021d","DOIUrl":"https://doi.org/10.2298/hemind200413021d","url":null,"abstract":"Biperiden, an antiparkinsonian anticholinergic drug, has been found to inhibit enzymatic hydrolysis of butyrylthiocholine iodide, which is catalyzed by serum cholinesterase. By measuring the difference in the basic and inhibitory hydrolysis reaction rates, in the presence of biperiden as an inhibitor, it is possible to develop a kinetic method for its determination. Both systems, enzyme-substrate-chromogen and enzyme-substrate-chromogen-inhibitor, were characterized by biochemical parameters (KM = 0.326 ? 0.330 mmol dm-3; Vmax = 40 - - 99 ?mol dm-3 min-1), while inhibition was defined as non-competitive with the constant of inhibition Ki = 6.142 ?mol dm-3. The reaction conditions have been optimized followed by determination of the calibration curve, the corresponding equation and the limits of detection and quantification yielding 3.84 and 12.80 nmol dm-3, respectively. Using the calibration chart, it is possible to determine biperiden in different samples in the concentration range of 0.035?35.940 ?mol dm-3. Influence of a number of substances, found in the sample, on the reaction rate was also examined. The optimized method was applied for determination of biperiden in pharmaceutical preparations. Accuracy of the method was tested using the standard addition method. The proposed method has good sensitivity, selectivity, it is simple and fast, and above all easily accessible, and thus applicable in biochemical and pharmaceutical laboratories.","PeriodicalId":9933,"journal":{"name":"Chemical Industry","volume":"3 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91351969","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

High temperature materials: properties, demands and applications 高温材料:性能、要求及应用

Chemical Industry Pub Date : 2020-07-27 DOI: 10.2298/hemind200421019s

M. Šimic, A. Alil, Sanja Martinović, M. Vlahović, A. Savić, T. Volkov-Husović

引用次数: 5

Implementation of natural and artificial materials in Portland cement 在硅酸盐水泥中实施天然和人工材料

Chemical Industry Pub Date : 2020-07-01 DOI: 10.2298/hemind191216014d

Damir Barbir, Pero Dabic

引用次数: 1

Immobilization of laccase from Trametes versicolor on Lifetechtm supports for applications in degradation of industrial dyes 在lifetech载体上固定化彩板菌漆酶在工业染料降解中的应用

Chemical Industry Pub Date : 2020-07-01 DOI: 10.2298/hemind200320016b

M. Bebic, M. Banjanac, M. Ćorović, D. Milivojevič, B. Simovic, Z. A. Vukoicic, D. Mitrović, I. D. Bezbradica

{"title":"Immobilization of laccase from Trametes versicolor on Lifetechtm supports for applications in degradation of industrial dyes","authors":"M. Bebic, M. Banjanac, M. Ćorović, D. Milivojevič, B. Simovic, Z. A. Vukoicic, D. Mitrović, I. D. Bezbradica","doi":"10.2298/hemind200320016b","DOIUrl":"https://doi.org/10.2298/hemind200320016b","url":null,"abstract":"In this study, immobilization of laccase from Trametes versicolor on eight Lifetech? supports, with different characteristics (pore size, length of the spacer arm and functional groups), was studied and optimized for intended use in bioremediation for decolorization of industrial wastewaters. Out of six tested amino-functionalized supports, the most promising carrier was proved to be porous Lifetech? ECR8309F with primary amino groups and a C2 spacer arm. Onto this support, laccase is attached by forming electrostatic interactions so that the most active preparation has shown the activity of 66876 U/g support. On the other hand, during immobilization of laccase on epoxy-functionalized Lifetech? ECR8285F, via hydrophobic interactions and covalent bonding confirmed by a desorption assay, immobilization yield of 60 % and the activity of 118929 U/g were accomplished. Furthermore, immobilized enzyme on this support showed high capacity for decolorization of dyes (Lanaset? Violet B, Lanaset? Blue 2R, bromothymol blue and bromocresol green), by combination of both adsorption and enzyme degradation. Decolorization was in the range of 88 to 96 % after 4 h, with more than 80 % achieved after only 45 min. Also, this preparation demonstrated high operational stability during seven consecutive reuses in all examined dye reaction systems.","PeriodicalId":9933,"journal":{"name":"Chemical Industry","volume":"188 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86729233","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Validation of a novel perfusion bioreactor system in cancer research 新型灌注生物反应器系统在癌症研究中的验证

Chemical Industry Pub Date : 2020-07-01 DOI: 10.2298/hemind200329015s

Jasmina Stojkovska, Jovana Zvicer, M. Milivojevic, Isidora P Petrović, M. Stevanović, B. Obradovic

{"title":"Validation of a novel perfusion bioreactor system in cancer research","authors":"Jasmina Stojkovska, Jovana Zvicer, M. Milivojevic, Isidora P Petrović, M. Stevanović, B. Obradovic","doi":"10.2298/hemind200329015s","DOIUrl":"https://doi.org/10.2298/hemind200329015s","url":null,"abstract":"Development of drugs is a complex, time- and cost-consuming process due to the lack of standardized and reliable characterization techniques and models. Traditionally, drug screening is based on in vitro analysis using two-dimensional (2D) cell cultures followed by in vivo animal testing. Unfortunately, application of the obtained results to humans in about 90 % of cases fails. Therefore, it is important to develop and improve cell-based systems that can mimic the in vivo-like conditions to provide more reliable results. In this paper, we present development and validation of a novel, user-friendly perfusion bioreactor system for single use aimed for cancer research, drug screening, anti-cancer drug response studies, biomaterial characterization, and tissue engineering. Simple design of the perfusion bioreactor provides direct medium flow at physiological velocities (100?250 ?m s-1) through samples of different sizes and shapes. Biocompatibility of the bioreactor was confirmed in short term cultivation studies of cervical carcinoma SiHa cells immobilized in alginate microfibers under continuous medium flow. The results have shown preserved cell viability indicating that the perfusion bioreactor in conjunction with alginate hydrogels as cell carriers could be potentially used as a tool for controlled anti-cancer drug screening in a 3D environment.","PeriodicalId":9933,"journal":{"name":"Chemical Industry","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89333858","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Influence of nanofillers on the properties of siloxane elastomers 纳米填料对硅氧烷弹性体性能的影响

Chemical Industry Pub Date : 2020-05-01 DOI: 10.2298/hemind191011011m

Darko Manjenčić, J. Seitsonen, T. Radusin, N. Vukić, J. Budinski-Simendic, J. Cakić, I. Ristić

{"title":"Influence of nanofillers on the properties of siloxane elastomers","authors":"Darko Manjenčić, J. Seitsonen, T. Radusin, N. Vukić, J. Budinski-Simendic, J. Cakić, I. Ristić","doi":"10.2298/hemind191011011m","DOIUrl":"https://doi.org/10.2298/hemind191011011m","url":null,"abstract":"In this study, the influence of nanosilicon(IV)-oxide (with hydrophobic and hydrophilic functionalized surfaces) on the properties of siloxane elastomers was studied. The elastomers were prepared from vinyl and hydrogen oligosiloxanes, while the nanocomposites were obtained by addition of nanofillers at different concentrations (1, 5, 10 and 20 wt%). The chemical structure of the obtained materials was analyzed by Fourier transform infrared spectroscopy. Transmission electron microscopy confirmed good dispersion of the hydrophobic filler within the polymer matrix, while the hydrophilic filler formed a net on the siloxane sample. Type of the filler modification did not affect hardness of the siloxane hybrid materials, while the samples with the highest content of hydrophobic nanosilica have shown the highest value of tensile strength. Influence of the nanosilica type on thermal degradation of elastomeric materials was investigated by using thermogravimetric analysis, while the influence of the fillers on the phase transition temperature was analyzed by differential scanning calorimetry. Lower compatibility of the hydrophobic matrix and hydrophilic filler caused a decrease in the crystalline melting temperature with the lowest value determined for the sample with the highest filler loading. Increase in the nanofiller content resulted in the improved thermal stability of the obtained hybrid materials.","PeriodicalId":9933,"journal":{"name":"Chemical Industry","volume":"6 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72578783","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

The role of science in modern society 科学在现代社会中的作用

Chemical Industry Pub Date : 2020-05-01 DOI: 10.2298/hemind200427013z

E. Živković

引用次数: 0