Eclética Química Journal最新文献_第2页

Effects of garnet particles and chill casting conditions on properties of aluminum matrix hybrid composites 石榴石颗粒和冷铸条件对铝基混杂复合材料性能的影响

Eclética Química Journal Pub Date : 2019-04-25 DOI: 10.26850/1678-4618EQJ.V44.2.2019.P45-52

H. Naeem, F. Abdullah

{"title":"Effects of garnet particles and chill casting conditions on properties of aluminum matrix hybrid composites","authors":"H. Naeem, F. Abdullah","doi":"10.26850/1678-4618EQJ.V44.2.2019.P45-52","DOIUrl":"https://doi.org/10.26850/1678-4618EQJ.V44.2.2019.P45-52","url":null,"abstract":"In recent years, the demand of high-performance and light-weight materials was increasing for industrial applications. The present research aims to study microstructural and mechanical properties of aluminum matrix hybrid reinforced 6-12 wt.% of garnet under the effects of materials chill casting during the manufacturing aluminum matrix composite. In this research work, metallic mold and no chills were used. In order to evaluate the quality of the chill end casting microstructure, hardness, and tensile tests were conducted on the prepared composite specimens. Aluminum matrix composites underwent the chill casting process have been examined using the optical microscope, scanning electron microscopy and X-ray diffraction. Microstructure outcomes of the casted Al-composites alloy indicated that having precipitations (Al2Si, AlCuMg2Si) and Garnet particulates hard within the Al-matrix. The results showed that the copper chill casting is the better one in terms of improving the mechanical properties because of its high volumetric heat capacity. Aluminum composite with addition of 9% Garnet composite produced via copper chill casting exhibits better mechanical properties.","PeriodicalId":11506,"journal":{"name":"Eclética Química Journal","volume":"84 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90659549","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: 4

Chemometrics in analytical chemistry – an overview of applications from 2014 to 2018 分析化学中的化学计量学——2014年至2018年的应用综述

Eclética Química Journal Pub Date : 2019-04-25 DOI: 10.26850/1678-4618EQJ.V44.2.2019.P11-25

M. Santos, P. A. M. Nascimento, W. N. Guedes, E. Pereira-Filho, É. R. Filletti, F. Pereira

引用次数: 18

Cobalt(II) chloride complexes with some phosphine oxides: compatibility between structural data for the solid complexes and their stability constants in acetone medium 氯化钴与某些氧化膦配合物:固体配合物的结构数据与它们在丙酮介质中的稳定性常数的相容性

Eclética Química Journal Pub Date : 2019-04-25 DOI: 10.26850/1678-4618EQJ.V44.2.2019.P53-55

A. Massabni, Cristo Bladimiros Melios

引用次数: 0

Study of the colloidal stability and optical properties of sunscreen creams 防晒乳胶体稳定性及光学性能的研究

Eclética Química Journal Pub Date : 2019-04-25 DOI: 10.26850/1678-4618EQJ.V44.2.2019.P26-36

Gustavo Pereira Saito, Mariana Bizari, M. Cebim, M. Correa, M. Jafelicci Junior, M. Davolos

引用次数: 4

Chromium speciation in leather samples: an experiment using digital images, mobile phone and environmental concepts 皮革样品中的铬形态:利用数码图像、手机和环保概念的实验

Eclética Química Journal Pub Date : 2019-01-28 DOI: 10.26850/1678-4618EQJ.V44.1.2019.P62-74

V. Costa, Ariane Maciel Neiva, E. Pereira-Filho

{"title":"Chromium speciation in leather samples: an experiment using digital images, mobile phone and environmental concepts","authors":"V. Costa, Ariane Maciel Neiva, E. Pereira-Filho","doi":"10.26850/1678-4618EQJ.V44.1.2019.P62-74","DOIUrl":"https://doi.org/10.26850/1678-4618EQJ.V44.1.2019.P62-74","url":null,"abstract":"This study proposes a new and simple method for Cr speciation and Cr(VI) determination in leather samples using digital images. The experiments were performed using a mobile phone and a free app called PhotoMetrix that was used to obtain and process data. The results obtained from PhotoMetrix were compared to reference methods using UV−Vis spectroscopy. A statistical evaluation between both proposed and the reference methods using two-sample t-test did not show a significant difference at a 95% confidence level. Bovine leather samples (4 samples) tanned with Cr salts and ovine leather samples (3 samples) tanned with vegetable tannin were analyzed. The proposed method presented limits of detection (LOD) and quantification (LOQ) of 0.6 and 2 mg/kg, respectively. In addition, the proposed method using PhotoMetrix and digital images can provide undergraduate students an opportunity to learn topics such as quantitative analyses, environmental chemistry, speciation chemistry, image processing and treatment of statistical data. The results demonstrated that the proposed method can be applied to routine analyses and in experimental analytical chemistry courses.","PeriodicalId":11506,"journal":{"name":"Eclética Química Journal","volume":"37 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81193475","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: 8

Voltammetric method for the quantification of cadmium using non-commercial electrodes and minimal instrumentation 用非商业电极和最小仪器测定镉的伏安法

Eclética Química Journal Pub Date : 2019-01-28 DOI: 10.26850/1678-4618EQJ.V44.1.2019.P53-61

Javier Ernesto Vilasó Cadre, Alejandro Céspedes Martínez, M. A. A. Pérez, José Alejandro Baeza Reyes

{"title":"Voltammetric method for the quantification of cadmium using non-commercial electrodes and minimal instrumentation","authors":"Javier Ernesto Vilasó Cadre, Alejandro Céspedes Martínez, M. A. A. Pérez, José Alejandro Baeza Reyes","doi":"10.26850/1678-4618EQJ.V44.1.2019.P53-61","DOIUrl":"https://doi.org/10.26850/1678-4618EQJ.V44.1.2019.P53-61","url":null,"abstract":"A voltammetric method for the cadmium quantification was developed using minimal instrumentation. A manual homemade potentiostat for linear voltammetry was used. An Ag reference electrode and auxiliary and working electrodes of writing graphite were employed for the electroanalysis. The electrolytic conditions for the quantification were stablished. Linearity, detection and quantification limits, precision and accuracy were evaluated. The conditions for the quantification were 1 mol/L of KCl as supporting electrolyte, pH 5 and 10 s for the current sampling. The range of quantification was from 10-3 to 1.5∙10-2 mol/L. The linear correlation (r), determination (R2) and adjusted (R2adj.) coefficients were 0.9986, 0.9972 and 0.9970. The detection and quantification limits were 3∙10-4 mol/L and 10-3 mol/L. Results showed an acceptable repeatability, with coefficients of variation from 1.5 to 5.8 % depending of the concentration. Uncertainty associated with the cadmium concentration was in the range of 1.2∙10-4 to 7∙10-5 mol/L, diminishing with the increasing of the concentration. A good accuracy was observed, with recoveries between 86.84 and 109.64 %.","PeriodicalId":11506,"journal":{"name":"Eclética Química Journal","volume":"25 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86089073","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

A review on the state-of-the-art advances for CO2 electro-chemical reduction using metal complex molecular catalysts 金属络合分子催化剂在CO2电化学还原中的研究进展

Eclética Química Journal Pub Date : 2019-01-28 DOI: 10.26850/1678-4618EQJ.V44.1.2019.P11-39

H. Louis, O. Akakuru, Philip Monday, O. O. Funmilayo

{"title":"A review on the state-of-the-art advances for CO2 electro-chemical reduction using metal complex molecular catalysts","authors":"H. Louis, O. Akakuru, Philip Monday, O. O. Funmilayo","doi":"10.26850/1678-4618EQJ.V44.1.2019.P11-39","DOIUrl":"https://doi.org/10.26850/1678-4618EQJ.V44.1.2019.P11-39","url":null,"abstract":"Significantly, global warming which is caused by CO2 emission and energy shortage are global problems resulting from artificial photosynthesis because it required many functions (light harvesting, Z water, and oxidation scheme). Therefore, photocatalytic systems development for CO2 reduction is germane in this field. Metal complexes molecular catalyst have become prevalent homogeneous catalysts for carbon dioxide (CO2) photocatalytic reduction since it was initially known as CO2 reduction catalysts in the 70s and the 80s, while utmost part involved macrocyclic cobalt(II) and nickel(II) complexes. This review article presents a broad understanding on some active catalysts recently reported as a metal complex molecular catalytic schemes for CO2 reduction, alongside catalytic activity, stability, selectivity under electro-reduction, and photoreduction circumstances. The progress of in situ spectroelectrochemical methods, typically supported via theoretical calculations, helped to access this know-how by providing information which enabled researchers to acquire more in-depth perception into unveiling the catalytic reaction and mechanisms intermediates.","PeriodicalId":11506,"journal":{"name":"Eclética Química Journal","volume":"20 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86794852","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

Electrochemical remediation of industrial pharmaceutical wastewater containing hormones in a pilot scale treatment system 含激素工业制药废水的电化学修复中试研究

Eclética Química Journal Pub Date : 2019-01-28 DOI: 10.26850/1678-4618EQJ.V44.1.2019.P40-52

R. L. Morais, L. F. Garcia, E. K. Moreno, Douglas Vieira Thomaz, L. Rodrigues, L. Brito, G. S. Lobón, G. Oliveira, M. F. Rodrigues, B. Vaz, E. Gil

{"title":"Electrochemical remediation of industrial pharmaceutical wastewater containing hormones in a pilot scale treatment system","authors":"R. L. Morais, L. F. Garcia, E. K. Moreno, Douglas Vieira Thomaz, L. Rodrigues, L. Brito, G. S. Lobón, G. Oliveira, M. F. Rodrigues, B. Vaz, E. Gil","doi":"10.26850/1678-4618EQJ.V44.1.2019.P40-52","DOIUrl":"https://doi.org/10.26850/1678-4618EQJ.V44.1.2019.P40-52","url":null,"abstract":"The elimination of residual drugs from pharmaceutical and domestic sources is a growing concern, as they are able to reach water and soil resources and can present environmental and health risks even in very low concentrations. Traditional water and wastewater treatment systems have not been efficient in the removal of these compounds, evidencing the importance of the development of new remediation methods. In view of the applicability and versatility of electrocoagulation techniques in the removal of pollutants, the aim of this work is to evaluate the parameters: biochemical oxygen demand (BOD), chemical oxygen demand (COD), color, turbidity, algestone acetophenide (AAc) and estradiol enanthate (EEn) using a pilot treatment system, as well as phytotoxicity and Brine shrimp toxicity. The study showed good removal efficiency, comprising remarkable remediation performance assayed through BOD (61.5%), COD (58.6%), color (83.1%), turbidity (96.7%), AAc (77.0%) and EEn (56.7%) after 30 minutes. For toxicity, raw effluent was considered more phytotoxic for lettuce and cucumber seeds when compared to treated effluent. The results suggest that the pilot prototype was promising, providing an increase in both the germination potential and the root growth of the seeds (Lactuca sativa and Cucumis sativus) and a significant decrease in the acute toxicity to Artemia salina.","PeriodicalId":11506,"journal":{"name":"Eclética Química Journal","volume":"40 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74583187","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: 12

Physicochemical and biological activity studies on complexes of some transition elements with mixed ligands of glycine and urea 一些过渡元素与甘氨酸和尿素混合配体配合物的物理化学和生物活性研究

Eclética Química Journal Pub Date : 2018-12-05 DOI: 10.26850/1678-4618EQJ.V43.4.2018.P25-36

M. A. Al.Maqtari, M. K. Al-qadasy, Y. Jamil, F. Al-Azab, A. A. Al-Gaadbi

引用次数: 1

Simple, fast and inexpensive method for determination of ranitidine hydrochloride based on conductometric measurements 电导法测定盐酸雷尼替丁的简便、快速、廉价方法

Eclética Química Journal Pub Date : 2018-12-05 DOI: 10.26850/1678-4618eqj.v43.4.2018.p37-43

E. H. Bindewald, João Carlos Rosa-Sobrinho, M. Bergamini, L. Marcolino-Junior

{"title":"Simple, fast and inexpensive method for determination of ranitidine hydrochloride based on conductometric measurements","authors":"E. H. Bindewald, João Carlos Rosa-Sobrinho, M. Bergamini, L. Marcolino-Junior","doi":"10.26850/1678-4618eqj.v43.4.2018.p37-43","DOIUrl":"https://doi.org/10.26850/1678-4618eqj.v43.4.2018.p37-43","url":null,"abstract":"This work aims the development and optimization of an alternative method for ranitidine hydrochloride (RAN-HCl) determination. The proposed method was based on conductometric titration of RAN by precipitation of AgCl solid using a solution of AgNO3 as titrant. It was investigated the possibility of performing the titrations on hydroalcoholic and deionized water medium. A limit of detection of 1.0 mmol L-1 and 0.5 mmol L-1 were achieved for RAN titration in deionized water and in a 75:25 hydroalcoholic mixture, respectively. Such behavior is attributed to the dielectric constant of hydroalcoholic medium, which is lower than aqueous solution, making AgCl more insoluble and improving the resolution of the conductivity curve around the end point. Therefore, it is concluded that the conductometric titration method to determine RAN using AgNO3 as titrant proved to be feasible at low drug concentrations. The statistical calculations for obtained results suggested good precision for the conductometric method. According to t-test, there were no significant differences between found values at a 95% confidence level. Moreover, obtained results showed an excellent performance of the proposed method on quality control of RAN-HCl in generic formulations without any sample pretreatment.","PeriodicalId":11506,"journal":{"name":"Eclética Química Journal","volume":"28 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75091358","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