Ovidius University Annals of Chemistry最新文献_第4页

Glycosylated stigmasterol from the rind of Napoleonaea imperialis 从拿破仑的果皮中提取的糖基化的豆甾醇

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Ovidius University Annals of Chemistry Pub Date : 2022-01-01 DOI: 10.2478/auoc-2022-0001

G. Ndukwe, I. Jack, R. E. Ekong

引用次数: 0

Catalytic pyrolysis of low density polyethylene and polypropylene wastes to fuel oils by N-clay n -粘土催化低密度聚乙烯和聚丙烯废弃物裂解制燃料油的研究

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Ovidius University Annals of Chemistry Pub Date : 2022-01-01 DOI: 10.2478/auoc-2022-0007

S. Adoga, O. Igbum, Glory Okopi, B. A. Ikyenge, Okwori Isaacs Ochi, P. Ode

{"title":"Catalytic pyrolysis of low density polyethylene and polypropylene wastes to fuel oils by N-clay","authors":"S. Adoga, O. Igbum, Glory Okopi, B. A. Ikyenge, Okwori Isaacs Ochi, P. Ode","doi":"10.2478/auoc-2022-0007","DOIUrl":"https://doi.org/10.2478/auoc-2022-0007","url":null,"abstract":"Abstract Dealing effectively with plastic wastes has been a major global challenge. Different methods have been previously employed to proffer solution to plastic wastes problem however, all showed their energetic, economic and environmental implications. In this research, catalytic pyrolysis of low density polyethylene and polypropylene wastes was carried out to proffer solution to the problem. The plastic materials were collected and appropriately prepared after which ultimate and proximate analysis was carried out on them. The clay was collected from Naka, Gwer West Local Government Area of Benue State, Nigeria, thereafter, referred to as N-clay and was appropriately prepared, then analyzed by a BET analyzer for the following properties: the surface area, which was found to be 85.418 m2/g, pore size 2.100 nm and pore volume of 0.042 cc/g. Also, the XRF determination of the chemical composition of the N-clay was done and the SiO2/Al2O3 ratio was found to be 70.81/29.19. The N-clay and the plastics were then pyrolyzed in a chemical vapor deposition (CVD) reactor in the ratio 1:3 respectively, at 500 oC with residence time of 30 min using nitrogen as purge gas. The polypropylene yielded 70.34 % liquid oil, 6.43 % char and 23.23 % gas. The liquid was analyzed for functional groups, using Raman spectrometer. Physicochemical analysis was also done on the oil and it was determined that the oil had properties consistent with commercial-grade gasoline. The low density polyethylene yielded wax, instead of liquid, char and gas. Finally, it was concluded that the N-clay was suitable as catalyst for the pyrolysis of plastics and the fuel oil obtained from polypropylene pyrolysis is comparable to gasoline fuel.","PeriodicalId":19641,"journal":{"name":"Ovidius University Annals of Chemistry","volume":"59 1","pages":"50 - 55"},"PeriodicalIF":0.9,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84003105","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

Synthesis and characterization of novel poly(α-methyl β-alanine-b-lactone)s through hydrogen-transfer and ring-opening polymerization 新型聚α-甲基β-丙氨酸-b-内酯的氢转移和开环聚合合成及表征

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Ovidius University Annals of Chemistry Pub Date : 2022-01-01 DOI: 10.2478/auoc-2022-0011

E. Çatıker, Songül Kirlak, M. Atakay, B. Salih

引用次数: 0

Preparation and physico-chemical study of fire retardant from chicken feathers and PP/PE composites 鸡毛与PP/PE复合材料阻燃剂的制备及理化研究

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Ovidius University Annals of Chemistry Pub Date : 2022-01-01 DOI: 10.2478/auoc-2022-0010

A. D. Mohammed, Y. Alhassan

{"title":"Preparation and physico-chemical study of fire retardant from chicken feathers and PP/PE composites","authors":"A. D. Mohammed, Y. Alhassan","doi":"10.2478/auoc-2022-0010","DOIUrl":"https://doi.org/10.2478/auoc-2022-0010","url":null,"abstract":"Abstract Chicken feathers were used to reinforce low density polyethylene (LDPE) and polypropylene (PP). The physico-mechanical and flame retardation properties of the composites were investigated. Properties such as tensile strength, elongation at break, flexural strength, and modulus as well as water absorbency were determined and the results obtained were analyzed. The composites were further characterized by SEM and FTIR analyses to study the surface morphology and evidence of composite formation respectively. The Young modulus of reinforced composites were greater than that of virgin samples. The fiber/Polypropylene samples were observed to have the highest value of Young modulus, with a value of 133.33 GPa, and tensile strength value of 16.93 MPa. TGA and flame retardant tests were carried out to investigate the flame propagation and thermal properties of the composites. The results showed that the mechanical properties of composites from polypropylene were better enhanced than those from the composites of polyethylene, with an overall increase in mechanical properties when compared to the virgin polymers used. From the TGA and flame retardant test, it was observed that the more the fiber load the more the formation of char layers in the samples, hence retards the flame formation and reduced prolonged burning and flame propagation.","PeriodicalId":19641,"journal":{"name":"Ovidius University Annals of Chemistry","volume":"33 1","pages":"71 - 77"},"PeriodicalIF":0.9,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82555792","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

Synthesis and characterization of poly(ε-caprolactone) tetra-arm star polymer using tetra terminal alkynyl-substituted phthalocyanine by the combination of ring-opening polymerization and “click” chemistry 用开环聚合和“咔嗒”化学相结合的方法合成四端炔基取代酞菁聚ε-己内酯四臂星形聚合物

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Ovidius University Annals of Chemistry Pub Date : 2022-01-01 DOI: 10.2478/auoc-2022-0003

B. Savaş, E. Meyvacı, T. Öztürk, M. Ağırtaş

{"title":"Synthesis and characterization of poly(ε-caprolactone) tetra-arm star polymer using tetra terminal alkynyl-substituted phthalocyanine by the combination of ring-opening polymerization and “click” chemistry","authors":"B. Savaş, E. Meyvacı, T. Öztürk, M. Ağırtaş","doi":"10.2478/auoc-2022-0003","DOIUrl":"https://doi.org/10.2478/auoc-2022-0003","url":null,"abstract":"Abstract The synthesis of poly(ε-caprolactone) (PCL) tetra-arm star polymer was carried out using “click” chemistry and ring-opening polymerization techniques. For this purpose, poly(ε-caprolactone) azido (PCL-N3) was acquired using ring-opening polymerization of ε-caprolactone and 2-[2-(2-azidoethoxy)ethoxy]ethanol (N3ol). N3ol was obtained using sodium azide and 2-[2-(2-chloroethoxy)ethoxy]ethanol. 4-(prop-2-ynyloxy)-phthalonitrile was obtained by using 4-nitrophthalonitrile and propargyl alcohol. 2(3),9(10),16(17),23(24) Tetrakis-[(prop-2-ynyloxy)-phthalocyaninato]zinc(II) (Pc-propargyl) was synthesized by using 4-(prop-2-ynyloxy)-phthalonitrile and a metal salt. By reacting Pc-propargyl and PCL-N3, PCL tetra-arm star polymer was obtained by “click” chemistry. The products were characterized via scanning electron microscopy, 1H-nuclear magnetic resonance spectroscopy, ultraviolet-visible spectrophotometry, Fourier-transform infrared spectroscopy, and gel permeation chromatography instruments. The spectroscopic analyses of PCL tetra-arm star polymer prove that the star polymer was built through the combination of ROP and “click” chemistry. We provided a protocol for PCL tetra-arm star polymer, and a statement of reproducibility with respect to the properties of this tetra-arm star polymer. This study is an example of a novel type of combination reaction, from ring-opening polymerization to “click” chemistry using phthalocyanine. This can open the door for diverse tetra-arm star polymer synthesis that could potentially cause major advances in synthetic macromolecular chemistry.","PeriodicalId":19641,"journal":{"name":"Ovidius University Annals of Chemistry","volume":"8 1","pages":"17 - 22"},"PeriodicalIF":0.9,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79569865","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

Flow behavior of Algerian crude oils from different sources 不同来源阿尔及利亚原油的流动特性

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Ovidius University Annals of Chemistry Pub Date : 2022-01-01 DOI: 10.2478/auoc-2022-0009

Ahmed Salah Eddine Meddour, Farid Souas

引用次数: 2

Physico-chemical and sensory quality of pasteurized apple juices extracted by blender and cold pressing juicer 用搅拌器和冷压榨汁机榨出的巴氏苹果汁的理化和感官品质

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Ovidius University Annals of Chemistry Pub Date : 2022-01-01 DOI: 10.2478/auoc-2022-0012

C. Ghinea, A. Prisacaru, A. Leahu

{"title":"Physico-chemical and sensory quality of pasteurized apple juices extracted by blender and cold pressing juicer","authors":"C. Ghinea, A. Prisacaru, A. Leahu","doi":"10.2478/auoc-2022-0012","DOIUrl":"https://doi.org/10.2478/auoc-2022-0012","url":null,"abstract":"Abstract Worldwide, one of the most consumed fruit juices is apple juice, preferred by both adults and children due to its authentic taste, but also due to its nutritional and health benefits. Apple juice contains sugars, malic acid, soluble pectin, vitamin C, phytochemicals and minerals. The production process influences the juice composition. There is a growing market for natural cloudy apple juice, even though fruit juice is mostly consumed as clear juice. The aim of this study was to obtain cloudy apple juice by using a blender and a cold pressing juicer for extraction and to evaluate their physico-chemical and sensory qualities. The apple juice samples were obtained from three different apple cultivars: “Gala”, “Braeburn” and “Golden Delicious”. After extraction, apple juice samples were pasteurized and cooled. In this study, physico-chemical analyzes (like moisture, water activity, pH, titratable acidity, total soluble solids, electrical conductivity, color parameters) were performed immediately after processing and at 7, 14, 21 days of storage at room temperature. The results showed that the investigated parameters of the apple juice samples varied differently depending on both the apple cultivar and the processing method used. Sensory analysis showed that certain types of apples can be suitable for extracting juice using a blender (“Golden Delicious”), while others such as “Gala” apples can be used to obtain juice by cold pressing.","PeriodicalId":19641,"journal":{"name":"Ovidius University Annals of Chemistry","volume":"1 1","pages":"84 - 93"},"PeriodicalIF":0.9,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88897577","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

Toxic metals in soil depths from selected abandoned sites: Occurrence, sources, ecological and human health risk 选定废弃场地土壤深处的有毒金属:发生、来源、生态和人类健康风险

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Ovidius University Annals of Chemistry Pub Date : 2022-01-01 DOI: 10.2478/auoc-2022-0002

O. O. Emoyan, G. Tesi, E. Ohwo, C. Olisah

引用次数: 0

Entropy generation analysis in a gasket plate heat exchanger using non-spherical shape of alumina boehmite nanoparticles 利用非球形氧化铝薄水铝石纳米颗粒对垫片板式换热器进行熵产分析

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Ovidius University Annals of Chemistry Pub Date : 2022-01-01 DOI: 10.2478/auoc-2022-0006

E. Nogueira

{"title":"Entropy generation analysis in a gasket plate heat exchanger using non-spherical shape of alumina boehmite nanoparticles","authors":"E. Nogueira","doi":"10.2478/auoc-2022-0006","DOIUrl":"https://doi.org/10.2478/auoc-2022-0006","url":null,"abstract":"Abstract The analysis deals with the thermo-hydraulic performance of a Gasket Plate Heat Exchanger used for cooling vegetable oils with a water-ethylene glycol 50% and volume fractions of non-spherical nanoparticles mixture as a refrigerant. The heat exchanger has 75 plates with a chevron angle equal to 30º. The Reynolds number of the refrigerant varies from 80 to 1530. The Reynolds number of the sunflower vegetable oil is fixed and equal to 30. The non-spherical nanoparticles used for analysis are platelet, cylindrical and brick types. Graphical results are presented for global heat transfer coefficient, heat capacity ratio, heat transfer rate, outlet temperatures, thermal and viscous entropy generation rate, and Bejan thermodynamic number. The results obtained allow us to conclude that it is possible to work with low relative flow rates using non-spherical nanoparticles, emphasizing platelet nanoparticles. The entropy generations analysis shows that very high flow rates of the refrigerant dissipate much of the energy in viscous form and do not contribute to oil cooling, with a consequent increase in the heat exchanger operating costs.","PeriodicalId":19641,"journal":{"name":"Ovidius University Annals of Chemistry","volume":"24 1","pages":"41 - 49"},"PeriodicalIF":0.9,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76955435","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

Antioxidant potentials and anti-inflammatory properties of methanol extracts of ripe and unripe peels of Ananas comosus (L.) Merr. 红豆熟皮和未熟皮甲醇提取物的抗氧化活性和抗炎特性稳定。

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Ovidius University Annals of Chemistry Pub Date : 2022-01-01 DOI: 10.2478/auoc-2022-0013

B. Oso, I. Olaoye, Emmanuel N. Ekpo, G. Akhigbe

{"title":"Antioxidant potentials and anti-inflammatory properties of methanol extracts of ripe and unripe peels of Ananas comosus (L.) Merr.","authors":"B. Oso, I. Olaoye, Emmanuel N. Ekpo, G. Akhigbe","doi":"10.2478/auoc-2022-0013","DOIUrl":"https://doi.org/10.2478/auoc-2022-0013","url":null,"abstract":"Abstract Studies suggest that extracts from plant materials could play protective roles against various disorders associated with the interplay between oxidative response and inflammatory disorders. The aim of this study was to investigate the potential antioxidant and anti-inflammatory properties, and phytochemical analyses of methanol extract of ripe and unripe peels of Ananas comosus (L.) Merr. The antioxidant properties were investigated through the analyses of ferric ion reducing antioxidant capacities, ascorbic acid equivalent antioxidant capacities, and nitric oxide scavenging capacities of the extracts. The anti-inflammatory potentials of the extracts were assessed through albumin denaturation inhibition and proteinase inhibition assays. Further investigation was carried out on the phytochemical composition of the extracts. There was no significant difference in the antioxidant potentials of the extracts assessed through the reduction of ferric ion. However, the ascorbic acid equivalent capacities and nitric oxide scavenging potential revealed that the antioxidant potentials of the extract of the unripe peel of A. comosus were significantly higher (p < 0.05) than the antioxidant potentials of the extract of ripe peel. Albumin denaturation inhibitory potential was significantly higher (p < 0.05), but there was no significant difference in the protease inhibitory potentials of both extracts. The estimated amounts of total flavonoids present in the extract of ripe peel of A. comosus were significantly higher (p < 0.05) than the estimates in the extract of unripe peels. This study gave a comprehensive insight into the antioxidant properties, anti-inflammatory properties and phytochemical compositions of the methanol extracts of the peels of ripe and unripe A. comosus which could be exploited as an alternative and complementary medicine in the treatment of different ailments associated with inflammatory disorders.","PeriodicalId":19641,"journal":{"name":"Ovidius University Annals of Chemistry","volume":"16 1","pages":"94 - 98"},"PeriodicalIF":0.9,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91278587","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