Journal of Chemical Technology and Metallurgy最新文献_第6页

ELASTOHYDRODYNAMIC EFFECTS IN LUBRICATION OF JOURNAL BEARINGS UNDER TURBULENT CONDITIONS 湍流条件下轴颈轴承润滑中的弹性流体力学效应

Journal of Chemical Technology and Metallurgy Pub Date : 2024-05-07 DOI: 10.59957/jctm.v59.i3.2024.28

J. Javorova, Iliya Andonov, Traian Severin, L. Irimescu, Yovko Rakanov

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STUDY OF THE INFLUENCE OF CONSERVATION TREATMENT ON THE CHROMATIC CHARACTERISTICS OF ARABIC MANUSCRIPTS 研究保存处理对阿拉伯手稿色调特征的影响

Journal of Chemical Technology and Metallurgy Pub Date : 2024-05-07 DOI: 10.59957/jctm.v59.i3.2024.12

Iordanka Ivanova, I. Spiridonov, R. Boeva

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ENERGY AND POWER PARAMETERS OF ROLLING PROFILES FOR WHEEL RIMS WITH REDUCED METAL INTENSITY AND TAPERED SEATS 降低金属强度和锥形座轮辋轧制轮廓的能量和功率参数

Journal of Chemical Technology and Metallurgy Pub Date : 2024-05-07 DOI: 10.59957/jctm.v59.i3.2024.25

Valeriy Chigirinsky, Irina Volokitina

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ANTIBACTERIAL AND ANTIOXIDANT ACTIVITY OF COSMETIC CREAMS WITH EXTRACTS OF DRY FLOWERS AND FRUITS OF SAMBUCUS NIGRA L. - USE OF SAMBUCUS NIGRA L. AS A NON-TRADITIONAL CHEMICAL PRESERVATIVE 含有西洋接骨木干花和果实提取物的化妆品的抗菌和抗氧化活性 - 使用西洋接骨木作为非传统化学防腐剂

Journal of Chemical Technology and Metallurgy Pub Date : 2024-05-07 DOI: 10.59957/jctm.v59.i3.2024.7

Kamelia Petkova - Parlapanska, Yordan Handzhiyski, E. Georgieva, G. Nikolova, Y. Karamalakova

{"title":"ANTIBACTERIAL AND ANTIOXIDANT ACTIVITY OF COSMETIC CREAMS WITH EXTRACTS OF DRY FLOWERS AND FRUITS OF SAMBUCUS NIGRA L. - USE OF SAMBUCUS NIGRA L. AS A NON-TRADITIONAL CHEMICAL PRESERVATIVE","authors":"Kamelia Petkova - Parlapanska, Yordan Handzhiyski, E. Georgieva, G. Nikolova, Y. Karamalakova","doi":"10.59957/jctm.v59.i3.2024.7","DOIUrl":"https://doi.org/10.59957/jctm.v59.i3.2024.7","url":null,"abstract":"Natural ingredients rich in antioxidants and polyphenols in the forme of extracts, essential oils, organic acids have been used in the production of different cosmetic products. In the development of new cosmetic compositions, or the improvement of products already implemented in production, the evaluation of the user is of great importance, as it directly affects the demand for a given product. The present study aimed to produce phytocosmetic creams based on stearic acid with extracts of dry flower and fruit juice of Sambucus nigra L. (S. nigra) and to investigatein parallel their potential as substitutes for conventional preservatives. The obtained creams were determined for minimum inhibitory, and minimum bactericidal activity using three bacterial strains (Pseudomonas aeruginosa ATCC 27853, Staphylococcus aureus ATCC25923, Bacillus subtilis ATCC 6633). In addition, the antibacterial effect of creams against Escherichia coli (BW 28357) was determined. In our experiments we found that addition of dried flower extracts or elderberry fruit extracts from S. nigra in the emulsion does not disturb the compositional system. In conclusion, according to the results, the Sambucus nigra L. extracts from dry flowers and elderberry fruitsare appropriate for use in cosmetic emulsions that demonstated antioxidant stability and antibacterial properties.","PeriodicalId":38363,"journal":{"name":"Journal of Chemical Technology and Metallurgy","volume":"28 38","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141004376","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

STUDY OF STEELS FOR THE PURPOSE OF COMPARISON IN TERMS OF QUALITY INDICATORS AND ENERGY EFFECT OF THEIR PRODUCTION 对钢材进行研究，以比较其质量指标和生产对能源的影响

Journal of Chemical Technology and Metallurgy Pub Date : 2024-05-07 DOI: 10.59957/jctm.v59.i3.2024.24

Rositsa Gavrilova

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METHANE PRODUCTION FROM COW MANURE IN THE PRESENCE OF Bi(III) COMPLEX OF SULFAMIC ACID 硫酸铋(III)复合物作用下牛粪产生甲烷

Journal of Chemical Technology and Metallurgy Pub Date : 2024-05-07 DOI: 10.59957/jctm.v59.i3.2024.17

Anelia I. Tzanova, Nikolay Kaloyanov, Kamelia Ruskova, A. Zahariev

{"title":"METHANE PRODUCTION FROM COW MANURE IN THE PRESENCE OF Bi(III) COMPLEX OF SULFAMIC ACID","authors":"Anelia I. Tzanova, Nikolay Kaloyanov, Kamelia Ruskova, A. Zahariev","doi":"10.59957/jctm.v59.i3.2024.17","DOIUrl":"https://doi.org/10.59957/jctm.v59.i3.2024.17","url":null,"abstract":"The present study examines the process of biomethanization of cow manure in an anaerobic environment, in the presence of small amounts of Bi(III) complex of sulfamic acid. Since this complex has good antimicrobial activity, the purpose of adding the complex is to determine its effect on biogas and methane production. The reference samples (cow manure only) and mixtures of cow manure + 10 mg and cow manure + 20 mg of bismuth complex with a composition [Bi6O4(OH)4](NH2SO3)6 are subjected to biodegradation under the following conditions – duration of 33 days, nitrogen atmosphere and temperature of 34.5 ± 1°C. During the process, the volume of biogas and the percentage content of methane in biogas are measured in 2 - 3 days as well. The analyses performed reveal that until the 10th day, the amount of biogas produced increases constantly and is comparable both for the control samples and for the mixtures. Further, until the end of the experiment, a significant and constant increase in the volume of biogas produced by the mixtures is observed compared to the control samples.Regarding the percentage of methane produced by the reference samples and the mixtures, comparable relative amounts are found by the 7th day. From the 8th day to the 33rd day, the percentage of methane released by the mixtures is visibly greater than that by the reference samples.","PeriodicalId":38363,"journal":{"name":"Journal of Chemical Technology and Metallurgy","volume":"22 44","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141005826","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

METHODOLOGY AND EQUIPMENT FOR RESEARCHING CORROSION CRACKING PROCESSES IN CASTING ALLOYS 研究铸造合金腐蚀开裂过程的方法和设备

Journal of Chemical Technology and Metallurgy Pub Date : 2024-05-07 DOI: 10.59957/jctm.v59.i3.2024.19

Maria Krasteva

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SYNTHESIS AND CHARACTERIZATION OF PURE AMORPHOUS SILICON OXIDE FROM TREATED KAOLINITIC CLAY USING CHEMICAL EXTRACTION 利用化学萃取法从经处理的高岭土中合成纯无定形氧化硅并确定其特性

Journal of Chemical Technology and Metallurgy Pub Date : 2024-05-07 DOI: 10.59957/jctm.v59.i3.2024.15

Sunday G. Borisade, S. Owoeye, Aderonke Ayeni

{"title":"SYNTHESIS AND CHARACTERIZATION OF PURE AMORPHOUS SILICON OXIDE FROM TREATED KAOLINITIC CLAY USING CHEMICAL EXTRACTION","authors":"Sunday G. Borisade, S. Owoeye, Aderonke Ayeni","doi":"10.59957/jctm.v59.i3.2024.15","DOIUrl":"https://doi.org/10.59957/jctm.v59.i3.2024.15","url":null,"abstract":"Pure silicon oxide was produced in this study utilizing a sodium silicate solution made from Kankara clay as a precursor. The Kankara clay that was obtained from Nigeria was first beneficiated to produce pure dried powder clay. After that, the dried powdered clay was treated with heat activation and acid leaching, respectively. In a 500 mL Erlenmeyer flask, appropriate amounts of each clay (raw, thermally treated clay, and leached clay) were reacted with 3M NaOH solution. The flask was heated to 200°C and stirred continuously for 3 hours on a magnetic stirring hot plate connected to a reflux condenser. The solution was filtered to yield sodium silicate solution, which was then precipitated with 3M HCl while constantly stirring to produce a gelly-like white substance. The gel was aged for 18 hours, then washed with de-ionized water several times before being dried at 80°C for 12 hours to get pure white silica particles, which were subsequently described. The XRD analysis revealed that the silicon oxide synthesized is amorphous, but the microstructure evaluation revealed particles aggregation, which is usual in sol-gel synthesized powder.","PeriodicalId":38363,"journal":{"name":"Journal of Chemical Technology and Metallurgy","volume":"24 8","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141005102","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

RESOURCE-SAVING WHEAT STRAW PROCESSING TECHNOLOGY 小麦秸秆资源节约型加工技术

Journal of Chemical Technology and Metallurgy Pub Date : 2024-05-07 DOI: 10.59957/jctm.v59.i3.2024.11

Iryna Trembus, Nazarii Mykhailenko

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COMPARATIVE STUDY OF POLYPHENOLIC COMPOSITION AND REDUCING PROPERTIES OF EXTRACTS OF CANNABIS SATIVA L., CANNABIS INDICA AND CANNABIS HYBRID 大麻、籼大麻和杂交大麻提取物中多酚成分和还原特性的比较研究

Journal of Chemical Technology and Metallurgy Pub Date : 2024-02-29 DOI: 10.59957/jctm.v59.i2.2024.1

Nikolay Vetskov, Nikolay Kaloyanov, I. Hinkov, S. Diankov, Katya Pashova, Vanya Gerasimova, Milena Funeva-Peycheva, Todorka Yankovska-Stefanova, Atanas Garbev

{"title":"COMPARATIVE STUDY OF POLYPHENOLIC COMPOSITION AND REDUCING PROPERTIES OF EXTRACTS OF CANNABIS SATIVA L., CANNABIS INDICA AND CANNABIS HYBRID","authors":"Nikolay Vetskov, Nikolay Kaloyanov, I. Hinkov, S. Diankov, Katya Pashova, Vanya Gerasimova, Milena Funeva-Peycheva, Todorka Yankovska-Stefanova, Atanas Garbev","doi":"10.59957/jctm.v59.i2.2024.1","DOIUrl":"https://doi.org/10.59957/jctm.v59.i2.2024.1","url":null,"abstract":"Cannabis Sativa L., Cannabis Indica and Cannabis Hybrid are widespread plant species that find legal use in many countries around the world. The first of them has found considerable application in medicine, cosmetics, building construction, textile and food industries. Cannabis Indica and Cannabis Hybrid are used as raw materials for the extraction of oils that are used as pain relievers as well as for recreation purposes. The aim of the present study is to compare the polyphenolic composition of extracts from the three types of plants, by the maceration method of dry green leaf mass consisting of inflorescences and leaves. Ethanol (99.9 %) is used as an extractant, and the duration of the maceration process is seven days, at room temperature and stirring. The polyphenol composition is determined using HPLC-DAD method. \u0000The following polyphenol composition is found in extracts of Cannabis Sativa L.: epigallocatechin, rutin, myricetin, quercetin and kaempferol. On the other hand, quercetin and kaempferol are detected in the Cannabis Indica samples, while epigallocatechin, quercetin and kaempferol are present in the hybrid sort. In addition, green synthesis of silver nanoparticles by using sunlight or microwave irradiation was carried out to evaluate the reduction properties of three cannabis extracts. The least quantity of silver nanoparticles was obtained in the presence of Cannabis Sativa L. extracts. From the other two species of cannabis, microwave irradiation produces more silver nanoparticles, with smaller sizes, while exposure to direct sunlight produces fewer particles,but with larger sizes.","PeriodicalId":38363,"journal":{"name":"Journal of Chemical Technology and Metallurgy","volume":"25 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140416031","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