Chemical Engineering (Engineering) eJournal最新文献

{"title":"Comparison of the Structure and Properties Between Single Quench+temper and Double Quench+temper of Medium Carbon and Carbon Manganese Steel","authors":"Yurianto Yurianto, S. Sulardjaka, Susilo Adi Widyanto, Padang Yanuar","doi":"10.15587/1729-4061.2020.214223","DOIUrl":"https://doi.org/10.15587/1729-4061.2020.214223","url":null,"abstract":"Quenched and tempered steels are needed for highly-stressed structures in military and non-military equipment. This paper was written for studying the structure and properties (hardness and impact energy absorbed) of medium-carbon and carbon-manganese steels before and after Quench+Temper and Double Quenched+Tempered. Because water is cheap and easy to control, it was used as a quenching medium. This study compares the hardness and impact energy absorbed of quenched plus tempered and double quenched plus tempered steels. The results showed that double quenched plus tempered steel hardness was higher than in quenched plus tempered steels. Besides, the grain structure is refiner than that of quenched plus tempered steel. The taking of the austenite temperature and holding time is essential because of the hardness at the end of the quenching process. The study aims to obtain hardness and impact energy from quenching+tempering and double quenching+tempering of medium-carbon and carbon-manganese steel for armor steel. In the first step, five specimens were heated at 900 ℃ (held for 30 minutes), cooled in freshwater and produced Q 900 Steel. Then, these specimens were heated at 750 ℃, 800 ℃, 850 ℃, and 900 ℃, held for 30 minutes and provided Q 900+750 Steel, Q 900+800 , Q 900+850 Steel, and Q 900+900 Steel. These specimens were tempered at 150 ℃ (held for 30 minutes) and produced Q 900+750 &T Steel, Q 900+800 &T Steel, Q 900+850 &T Steel, Q 900+900 &T Steel. Martensite reached the cooling period 357 ℃ to 182 ℃, tempered at 150 ℃ (held for 30 minutes). Hardness for double-quenching and tempering is higher than for conventional. The maximum impact energy of double-quenching and tempering heat treatment of Q 900+850 &T steel is suitable for armor steel used","PeriodicalId":9858,"journal":{"name":"Chemical Engineering (Engineering) eJournal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88992937","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}

{"title":"Identification and Quantitative Determination of Clonidine by HPLC Method","authors":"O. Mamina, V. Kabachny","doi":"10.15587/2519-4852.2020.215101","DOIUrl":"https://doi.org/10.15587/2519-4852.2020.215101","url":null,"abstract":"The aim of this work is identification and quantification of clonidine hydrochloride by a unified HPLC method, which allows to obtain reliable and reproducible research results. Materials and methods. HPLC analysis was carried out on a microcolumn liquid chromatograph \"Milichrome A-02\" in conditions: reversed-phase variant, column with non-polar sorbent Prontosil 120-5 C 18 AQ, 5 μm; mobile phase in the mode of linear gradient – from eluent А (5 % acetonitrile and 95 % buffer solution) to eluent B (100 % acetonitrile) as during 40 min. The flow rate of the mobile phase has been formed 100 μl/min, injection volume – 4 μl. Multichannel detection of the substance was carried out using a UV detector at 210, 220, 230, 240, 250, 260, 280 and 300 nm; the optimal value of column temperature – 37 - 40°С and pressure of pump – 2.8 – 3.2 MPa. Results and its discussion. As a result of studies using a unified HPLC method, were obtained the retention parameters of clonidine hydrochloride and spectral relationships, which made it possible to include the results obtained in the database for the identification of antihypertensive drugs in the therapeutic monitoring of treatment with an individual drug, or comprehensive treatment of diseases of the cardiovascular system. The development of the quantitative determination of clonidine hydrochloride by HPLC on model solutions using various concentrations of the drug was carried out. The content of clonidine hydrochloride was determined according to the equation S = 0.5 · 10-4 C + 1.8 · 10-3; the correlation coefficient was 0.9964. It is established that the relative uncertainty of the average result did not exceed + 2.12 % when HPLC analysing of clonidine hydrochloride in model solutions. Conclusions. Identification and quantification of clonidine hydrochloride by a unified HPLC method, which allows to obtain reliable and reproducible research results were conducted. The results of research by a unified HPLC method can be recommended for implementation in the practice of forensic bureaus, toxicological centers, clinical laboratories for the study of drugs in biological objects","PeriodicalId":9858,"journal":{"name":"Chemical Engineering (Engineering) eJournal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89004711","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}

{"title":"The Influence of Dust Levels on Atmospheric Carbon Dioxide and Global Temperature","authors":"D. Allen, Danail Sandakchiev, Vincent J. Hooper, I. Ivanov","doi":"10.2139/ssrn.3721224","DOIUrl":"https://doi.org/10.2139/ssrn.3721224","url":null,"abstract":"\u0000 The purpose of this paper is to examine the causality between DUST, CO2 and temperature for the Vostok ice core data series [Vostok Data Series], dating from 420 000 years ago, and the EPICA C Dome data going back 800 000 years. In addition, the time-varying volatility and coefficient of variation in the CO2, dust and temperature is examined, as well as their dynamic correlations and interactions. We find a clear link between atmospheric C02 levels, dust and temperature, together with a bi-directional causality effects when applying both Granger Causality Tests (1969) and multi-directional Non-Linear analogues, i.e. Generalized Correlation. We apply both parametric and non-parametric statistical measures and testing. Linear interpolation with 100 years and 1000 years is applied to the three variables, in order to solve the problem of data points mismatch among them. The visualizations and descriptive statistics of the interpolated variables (using the two periods) show robustness in the results. The data analysis points out that variables are volatile, but their respective rolling mean and standard deviation remain stable. Additionally, 1000 years interpolated data suggests positive correlation between temperature and CO2, while dust is negatively correlated with both temperature and CO2.\u0000\u0000The application of the non-parametric Generalized Measure of Correlation to our data sets, in a pairwise fashion suggested that CO2 better explains temperature than temperature does CO2, that temperature better explains dust than dust does temperature, and finally that CO2 better explains dust than vice -versa. The latter two pairs of relationships are negative.\u0000\u0000The summary of the paper presents some avenues for further research, as well as some policy relevant suggestions.","PeriodicalId":9858,"journal":{"name":"Chemical Engineering (Engineering) eJournal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91349295","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}

{"title":"Investigating Equilibrium in the System of a Hydrogen Sulfide-Quinhydrone Absorbing Solution","authors":"A. Slyuzar, Yaroslav Kalymon, Z. Znak, A. Helesh","doi":"10.15587/1729-4061.2020.214425","DOIUrl":"https://doi.org/10.15587/1729-4061.2020.214425","url":null,"abstract":"This paper reports a study into the influence of sodium carbonate concentration (10, 30, and 50 kg/m 3 ) in the simultaneous presence of sodium thiosulfate (250 kg/m 3 ) and quinhydrone (5 kg/m 3 ) on the coefficient of the phase distribution of hydrogen sulfide in a quinhydrone absorbing solution. The research was carried out at the laboratory installation using chemical analysis methods of liquid and gas phases. It has been found that the coefficient of phase distribution increases dramatically with an increase in the degree of saturation of the quinhydrone solution with hydrogen sulfide. At the same time, in the presence of sodium thiosulfate in quinhydrone absorbing solutions, the coefficient of phase distribution increases compared to carbonate solutions of the same concentration. Thus, the partial hydrogen sulfide pressure over a quinhydrone solution at low degrees of hydrogen sulfide saturation (up to 3 %) is 5...10 times larger than that over soda solution, while at high degrees (60...80 %) it is almost the same. It can be argued that at the high concentrations of sodium carbonate and the degree of the saturation of quinhydrone solution with hydrogen sulfide the effect of sodium thiosulfate on the partial pressure of hydrogen sulfide decreases. An equation of the effect exerted by the NaНS concentration and the starting Na 2 CO 3 concentration on the H 2 S partial pressure over quinhydrone solutions has been proposed. Based on the experimental studies' results, the equilibrium constant values for a hydrogen sulfide chemisorption reaction involving a quinhydrone solution have been calculated. To ensure the high absorption capacity, the process of hydrogen sulfide chemisorption should be carried out using solutions with a maximum concentration of sodium carbonate, 40...50 kg/m 3 . The presence of ballast components (Na 2 S 2 O 3 , NaHCO 3 ) slightly reduces the sorption capacity of an absorbing solution. The results obtained could be used in engineering calculations and when developing technology for purification of fuel gases from hydrogen sulfide by a quinhydrone method.","PeriodicalId":9858,"journal":{"name":"Chemical Engineering (Engineering) eJournal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88162287","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}

{"title":"An Investigation of Granular Material Movement Due to Instability Post Impinging Upward Fluid","authors":"E. Yudiyanto, I. Wardana, D. Widhiyanuriyawan, N. Hamidi","doi":"10.15587/1729-4061.2020.209933","DOIUrl":"https://doi.org/10.15587/1729-4061.2020.209933","url":null,"abstract":"Granular is a form of material that is widely used in the industry. To move the granular material, energy is needed to form a flow of granular. Granular instability can be utilized to move granular material. Prevention of jamming and clogging is done by breaking down the parts of the granular, which are locking. Impinging fluid in the granular is used to create granular instability. An observation was made using the experimental method. The granular in the Hele-Shaw cell is shot with fluid in the granular body and results in instability motion. Fluid impinging breaks granular bonds and forms fluid cavities. Furthermore, the fluid cavity moves upward due to unstable conditions. Granular with a strong bond is loose in the form of the agglomerate. Agglomerate is destroyed in the process of moving because there is a drag force. Granular with weak bonds tries to maintain individually form fingering. Granular moves down in the settling process to find a stable position. Instability is affected by the bonds between the grains. A comparison between the cohesion force and the mass weight of the particles is expressed as a granular Bond number B og . In glass sand material, strong granular bonds occur at granular sizes below 100 µm. Granular bonds affect the movement of instability in groups. The value of the granular Bond number is greater than 1. At sizes of 100 to 230 µm, the granular bond still affects the granular instability with the fingering pattern in the granular motion. The value of the granular Bond number is close to 1. Granular sizes above 230 µm indicate the presence of non-dominant bonds between the grains. The individual granular mass is higher than the cohesion force that occurs at the interface between the granular, and the granular Bond number value is less than 1.","PeriodicalId":9858,"journal":{"name":"Chemical Engineering (Engineering) eJournal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87789623","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}

{"title":"Influence of Used Polyvinyl Alcohol Grade on the Electrochromic Properties of Ni(OH)2-PVA Composite Films","authors":"V. Kotok, V. Kovalenko","doi":"10.15587/1729-4061.2020.214239","DOIUrl":"https://doi.org/10.15587/1729-4061.2020.214239","url":null,"abstract":"Films based on nickel (II) oxides and hydroxides are used in electrochromic cells as one of the active materials that change their optical characteristics under the action of an electric current. Electrochemical deposition, due to which composite films of Ni(OH) 2 -polyvinyl alcohol (PVA) can be formed on the electrically conductive substrate, can become an alternative to expensive vacuum methods. The presented study is devoted to the study and improvement of the electrochemical method of deposition of Ni(OH) 2 -PVA electrochromic composite films. This study illustrates the influence of the grade of the used polyvinyl alcohol on the main qualitative characteristics of Ni(OH) 2 -PVA electrochromic composites. Four PVA grades have been used for the study: 17–99, 24–99, 30–99, and 30–88, which differ in the viscosity of solutions and the degree of hydrolysis. The deposition has been carried out by the electrochemical method in the presence of the listed grades of polymers dissolved in the electrolyte. As a result of the study, it has been shown that the properties of electrochromic films depend on the grade of PVA used. To a greater extent they depend on the degree of hydrolysis, and to a lesser extent – on the molecular weight of the polymer, expressed in terms of viscosity. Analysis of the data obtained makes it possible to assert that the degree of PVA hydrolysis has a greater effect on the final characteristics of the films than the viscosity of solutions. However, viscosity also affects the properties. Moreover, it has been found that there is some optimum for this value. In this case, in terms of the characteristics of the films obtained, the optimal PVA has been the one with an average viscosity (PVA 24-99) among polyvinyl alcohols of three grades with the same degree of hydrolysis. The results obtained make it possible to recommend the use of PVA with an average viscosity and a degree of hydrolysis of less than 99 %. Based on the literature data, assumptions have been made that allow explaining the results obtained by the change in the hydrophobicity of the film and the properties of the transparent SnO 2 :F layer on glass.","PeriodicalId":9858,"journal":{"name":"Chemical Engineering (Engineering) eJournal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75383866","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}

{"title":"Oil to Biodiesel from Two Potential Sources – A 360 Degree Comparative Study","authors":"S. Nandi","doi":"10.38177/ajast.2020.4313","DOIUrl":"https://doi.org/10.38177/ajast.2020.4313","url":null,"abstract":"Jatropha curcas oil (JCO) and karanja oil have been identified for the comparative study of production of renewable energy sources i.e. biodiesel as well as physico-chemical properties of biodiesel for its potentiality. Enzyme Novozyme 435 (Candida antarctica) is used as biocatalyst (8%) for the conversion in both the cases with 5:1 molar ratio of alcohol to oil for 8 hours with mixing intensity of 600 rpm at 550C. JCO shows higher conversion efficiency at these parameters than karanja oil. Biodiesels obtained from JCO and karanja oil are analysed based on physico-chemical properties like specific gravity, kinematic viscosity, density, calorific value, cetane number, flash point, cloud point and acid number. With regard to specific gravity, kinematic viscosity, density, calorific value and cetane number, the JCO biodiesel shows higher values than karanja biodiesel whereas flash point and cloud point of karanja biodiesel are higher than JCO biodiesel. With respect to the compositional analysis, JCO biodiesel contains 95.67% methyl ester but karanja biodiesel contains 92.57% methyl ester. Apart from this, triglycerides (TG), diglycerides (DG) and monoglycerides (MG) content of JCO and karanja oil biodiesel are 1.68%, 1.08%, 2.68% and 1.89%, 2.75% and 3.69% respectively.","PeriodicalId":9858,"journal":{"name":"Chemical Engineering (Engineering) eJournal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90908968","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}

{"title":"Determination of Internal Stresses During Pearlite Transformation of 0.8c–1.5Mn Steel Through In-Situ Neutron Diffraction","authors":"S. Morooka, Nobuo Nakada, Yuhki Tsukada, W. Gong, T. Kawasaki, S. Harjo","doi":"10.2139/ssrn.3708734","DOIUrl":"https://doi.org/10.2139/ssrn.3708734","url":null,"abstract":"In this study, in-situ neutron diffraction during pearlite transformation and isothermal holding at 873 K after cooling of a 0.8C–1.5Mn steel specimen from 1323 K were conducted to measure the transformation stresses related to a eutectoid transformation. The stress relaxation behavior in cementite was also monitored to elucidate the relaxation of transformation elastic strains during isothermal annealing after pearlite transformation. By referring to the stress-free lattice parameter of an extracted electrolytic single-phase cementite sample after the long-time isothermal holding at 873 K, the transformation stresses were successfully evaluated. As one of the main findings, the elastic volume strain in cementite was determined to be approximately − 0.362%.","PeriodicalId":9858,"journal":{"name":"Chemical Engineering (Engineering) eJournal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83239593","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}

{"title":"Mechanical Responses of Primary-α Ti Grains in Polycrystalline Samples: Part II - Bayesian Estimation of Crystal-Level Elastic-Plastic Mechanical Properties from Spherical Indentation Measurements","authors":"Andrew R. Castillo, Aditya Venkatraman, S. Kalidindi","doi":"10.2139/ssrn.3708743","DOIUrl":"https://doi.org/10.2139/ssrn.3708743","url":null,"abstract":"In the second part of the work, a two-step Bayesian framework is utilized for the estimation of values of the single crystal elastic constants as well as the initial slip resistances of the different slip families in the primary α-phase components in the Ti alloys of different compositions. These estimations are based on the spherical indentation measurements presented in part I of this series. The first step of the two-step Bayesian framework established a reduced-order model which captures the dependence of the indentation property as a function of the relevant crystal-level (intrinsic) material properties and the crystallographic lattice orientation in the indentation deformation zone. This reduced-order model is calibrated to high-fidelity results obtained from suitable crystal-plasticity finite element (CPFE) simulations. The second step involved the calibration of the indentation measurements obtained within the primary α-phase (from part I of this series) to the reduced-order model established in the first step. It is demonstrated that the protocols described above result in the successful generation of a comprehensive dataset of single crystal elastic-plastic properties across a collection of Ti alloys while accounting for the implicit uncertainties in the spherical indentation measurements.","PeriodicalId":9858,"journal":{"name":"Chemical Engineering (Engineering) eJournal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76178232","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}

{"title":"First-Principle Calculation on Critical Velocity for Cu and Al Cold-Spray Bonding","authors":"Chengsong Zhang, Qian Wang, Xiao-Tao Luo, N. Ma","doi":"10.2139/ssrn.3688748","DOIUrl":"https://doi.org/10.2139/ssrn.3688748","url":null,"abstract":"The first-principles calculation with a newly developed high-efficient computing method was firstly applied to prediction of critical velocity for Cu/Al cold-spray bonding without any empirical parameters. An excellent agreement between predicted values and experimental values was obtained. The bonding mechanism of cold-spray was clarified by analyzing the atomic response in displacement during cold-spray process. A mixed bonding mechanism of adiabatic shear instability and pressure-release was confirmed. The computing method could be popularized to extensive applications in critical velocity prediction.","PeriodicalId":9858,"journal":{"name":"Chemical Engineering (Engineering) eJournal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85194792","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}