Advanced Science, Engineering and Medicine最新文献

{"title":"Carbon-13 Nuclear Magnetic Resonance Chemical Shift Calculation Protocol Applied to Rigid Triterpenes Molecules","authors":"Rênica Alves de Morais Rocha, Thaís Forest Giacomello, A. M. J. C. Neto, G. S. Mota, F. L. Costa","doi":"10.1166/ASEM.2020.2636","DOIUrl":"https://doi.org/10.1166/ASEM.2020.2636","url":null,"abstract":"Nuclear magnetic resonance spectroscopy is one of the most powerful experimental techniques for obtaining three-dimensional structures of complex molecules, mainly for the analysis of the relative and absolute configurations of organic compounds. For this reason, this has become one\u0000 of the most promising tools in the field of chemistry. From the theoretical point of view, advanced computational protocols have been developed for calculating nuclear magnetic resonance, mainly hydrogen-1 and carbon-13, parameters of isolated molecules, in which the environmental effects\u0000 are neglected. These effects are predominantly related to the inherently large size of such systems, making conventional ab initio theories either very computationally demanding or even prohibitive. Despite the current advances in spectroscopic techniques, instances of revision of structures\u0000 erroneously established for natural products are still common in the literature. Therefore, it is still necessary the development of quantum-chemical protocols that may assist in the correct structural determination of these compounds. This work aimed to test a universal scaling factor, based\u0000 on a linear regression, for the calculation of carbon-13 nuclear magnetic resonance chemical shifts for rigid molecules, which has low computational cost and great accuracy to aid in the structural determination of natural products. The carbon-13 chemical shifts were calculated using the mPW1PW91/3-21G\u0000 level of theory. Scaled chemical shifts were obtained according to the relation: 1.14x(calculated chemical shifts)–4.71. To test the application of the created scaling factor to problems related to stereochemistry, we investigated its ability to differentiate pentacyclic triterpenes\u0000 regioisomers. Our results show that the mPW1PW91/3-21G//PM7 level of theory applied to the calculations, together with the use of the scaling factor, is an efficient and low-cost tool as an alternative to computational requirement approaches, usually applied to the calculation of carbon-13\u0000 nuclear magnetic resonance chemical shifts.","PeriodicalId":7213,"journal":{"name":"Advanced Science, Engineering and Medicine","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79311070","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":"Microstructural and Mechanical Characterizations of Chromium Carbides and Chromium Borides Layers Over Low-Carbon Steel Surface","authors":"R. Boubaaya, O. Allaoui, Y. Benarioua, M. Djendel","doi":"10.1166/ASEM.2020.2673","DOIUrl":"https://doi.org/10.1166/ASEM.2020.2673","url":null,"abstract":"Hard coatings based on chromium carbides and chromium borides are widely used in applications that require mechanical performance, i.e., high hardness and low friction coefficient and good corrosion resistance. In this work, we made layers of chromium carbides and chromium borides on\u0000 the surface of low carbon steel through some specific treatments. For chromium carbides, the cementation in a solid medium followed by electroplating of chromium on the surface and finally the application of annealing treatment at temperatures between 500 and 1100 °C for 1 hour. For chromium\u0000 borides, the boriding treatment in solid medium at 900 °C for 4 hours followed by chromium electroplating on the steel surface and finally the application of annealing treatment at temperatures at 950 °C for 1 and 2 hours. The obtained results show that, in the first case, the cemented\u0000 layer and the chromium deposited on the surface combine to form chromium carbides on the treated surface after annealing. Similarly, for the second case, boron diffusion and chromium deposition lead to chromium borides on the treated surface. The characteristics of the chromium carbides and\u0000 chromium borides obtained are very similar to those of chromium carbides and chromium borides obtained by other processes.","PeriodicalId":7213,"journal":{"name":"Advanced Science, Engineering and Medicine","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86511531","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":"Fuzzy-Based Torsional Oscillations Mitigation via Thyristor Switched Braking Resistor in Multi-Machine Power System","authors":"M. Fayez, F. Bendary, M. El-Hadidy, M. Mandor","doi":"10.1166/ASEM.2020.2653","DOIUrl":"https://doi.org/10.1166/ASEM.2020.2653","url":null,"abstract":"Turbine generator shaft torsional oscillations is an interdisciplinary power system dynamic problem as it involves mechanical and electrical engineering. Torsional oscillations occur in the mechanical for electrical reasons. Torsional oscillations cause fatigue life expenditure of the\u0000 mechanical shaft system. There have been great motivations to mitigate the shaft torsional oscillations especially when unrestricted high speed reclosure (HSR) is utilized on the overhead transmission lines emanating from a generation station. Mitigation of torsional oscillation compromises\u0000 between the use of HSR and preserving the mechanical integrity of the involved turbine generator set. Therefore, braking resistor (BR) controlled by fuzzy logic controller is presented in this paper as a low cost, reliable mean for torsional oscillations mitigation. BR was first utilized for\u0000 the system transient stability enhancement. It serves as an extra load capable of dissipating extra generated power in case of system severe faults close to a generation station consequently prevents generator pole slipping conditions. IEEE 3 machine 9 bus system is adopted in this paper to\u0000 test the effects of BR on shaft torsional oscillations mitigation in interconnected power system. Comparative simulation studies between the unsuccessful reclosure with and without fuzzy controlled BR prove the effectiveness of the scheme for mitigation of torsional oscillations significantly.","PeriodicalId":7213,"journal":{"name":"Advanced Science, Engineering and Medicine","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82302515","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":"Dependence of Resistivity on Thickness of Vacuum Deposited Copper Thin Films","authors":"Shrutidhara Sarma","doi":"10.1166/ASEM.2020.2644","DOIUrl":"https://doi.org/10.1166/ASEM.2020.2644","url":null,"abstract":"In depth understanding of resistivity of metals is of utmost importance for optimizing circuit designs and electrical systems. In this study, we investigated the relation between film thickness (in the range of 25−350 nm) and film resistivity of Cu thin films, with respect to\u0000 thin film temperature sensors. The films were deposited in a vacuum deposition chamber over pyrex substrates and the film resistances were measured using 4 point probe technique. The empirical relationship established by Lacy has been used along with our experimental results in order to calculate\u0000 the constants relating the filmsubstrate compatibility, which influences the change of resistivity with thickness.","PeriodicalId":7213,"journal":{"name":"Advanced Science, Engineering and Medicine","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82393731","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":"Positioning Effect on Free Convection with an Elliptical Plate Placed in a Circular Enclosure","authors":"Parth Patpatiya, Soumya, Bhavya Shaan, Bhavana Yadav","doi":"10.1166/ASEM.2020.2668","DOIUrl":"https://doi.org/10.1166/ASEM.2020.2668","url":null,"abstract":"In this analysis we have examined the process of the steady state laminar natural convection around heated elliptical plate with Rayleigh number 10^6 positioned inside a circular enclosure. The purpose of the numerical analysis is to analyze the behavior of isotherms, streamlines and\u0000 heat transfer rate in enclosure plate system due to the variation in the position of elliptical plate (r/D =0.00, 0.05, and 0.2) and aspect ratio, where the given diameter of the enclosure is D and r is the distance between the centre of elliptical plate and centre of\u0000 circle. Elliptical plate is inclined at different angles and results are summed up in relative manner. There are two cases, in first case aspect ratio a/D and b/D is varied and D is kept constant, whereas in second case aspect ratio a/D and b/D is kept constant\u0000 and D is varied. Temperature difference between the enclosure and the inner body (i.e., temperature of inner body is kept high as compared to the enclosure) is maintained. Two dimensional study is followed by considering air as a fluid in enclosure. The effects of the Heat Transfer\u0000 and Flow of Fluid are analyzed by the streamlines and isotherms plotted for the body placed inside enclosure. Value of local Nusselt number (Nu) is also plotted along the wall of elliptical plate and along the surface of the circular enclosure. For every aspect ratio isotherms and streamlines\u0000 had been plotted. This work has been validated with various other numerical studies and was in good conciliation.","PeriodicalId":7213,"journal":{"name":"Advanced Science, Engineering and Medicine","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84548085","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":"Cement Formation with Marble Powder as Substitute","authors":"D. Reymond, J. Sudarsan, S. Nithiyanantham","doi":"10.1166/ASEM.2020.2651","DOIUrl":"https://doi.org/10.1166/ASEM.2020.2651","url":null,"abstract":"Lately marble is viewed as most significant beautifying construction materials. MP is which severalty impact on nature and medical issues. Marble powder materials are a fine powder. It is developed from chopping, molding and washing process. The creation of cement is expanding about\u0000 3% yearly. The creation of 1 ton of cement frees around 1 ton of CO2 to the air. This explorationmeans to intend the impression of using MP as in part substitution of cement. Cement which is one of constituents utilized in the creation of concrete has gotten costly and scant because\u0000 of which development cost increments. In present investigation cement has been partially replaced with marble powder in five different percentage mixes of 0%, 5%, 10%, 15% and 20% weightiness of cement content in concrete. The key factor taken into concern is proportion of MP concrete is tested\u0000 for workability, compressive strength, flexural strength and tensile strength.","PeriodicalId":7213,"journal":{"name":"Advanced Science, Engineering and Medicine","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84811748","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":"Development of a Correlation for the Estimation of the Higher Calorific Value of Diesel, Based on Its Kinematic Viscosity and Density","authors":"Mrunal Bhalerao, Pooja Pangavhane, P. Dhamangaonkar","doi":"10.1166/ASEM.2020.2665","DOIUrl":"https://doi.org/10.1166/ASEM.2020.2665","url":null,"abstract":"Diesel is extensively used as a fuel in prime movers, boilers and other power generation plants. The higher calorific value of diesel gives a measure of the effective chemical energy stored in a unit amount of fuel. The higher calorific value is required for the efficiency calculation\u0000 of a machine and hence it directly affects the estimation of the gross turnover of a power plant. Traditionally the higher calorific value of diesel is determined by means of a bomb calorimeter; however, this procedure is time consuming and requires expensive, specialized equipment and oxygen\u0000 gas. In this paper the authors have developed a unified correlation relating the higher calorific value of diesel with its density and kinematic viscosity both. Kinematic viscosity and density can be measured easily and quickly using standard laboratory instruments. Thus, developing the correlation\u0000 has quickened the process of the estimation of the higher calorific value of diesel, and correlating two physical properties density and kinematic viscosity has made the estimation more accurate with a correlation coefficient of 0.985444 and a coefficient of determination of 0.9711 with a\u0000 standard error of 1.012414 J/kg only.","PeriodicalId":7213,"journal":{"name":"Advanced Science, Engineering and Medicine","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88289627","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":"A Simplified Software for Uncertainty Estimation Using Monte Carlo Method","authors":"Jasveer Singh, L. Kumaraswamidhas, Neha Bura, K. Kaushik, N. Sharma","doi":"10.1166/ASEM.2020.2667","DOIUrl":"https://doi.org/10.1166/ASEM.2020.2667","url":null,"abstract":"The current paper discusses about the application of Monte Carlo method for the evaluation of measurement uncertainty using in-house developed program on C++ platform. The Monte Carlo method can be carried out by fixed trials as well as adaptive trials using this program. The program\u0000 provides the four parameters viz. estimate of measurand, standard uncertainty in the form of standard deviation and end points of coverage interval as an output.","PeriodicalId":7213,"journal":{"name":"Advanced Science, Engineering and Medicine","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75674771","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":"Development of Nano-KIT for Synthesis of Silver and Gold Nanostructures with Emphasis on Biological Applications","authors":"B. Khade, P. Dongre","doi":"10.1166/ASEM.2020.2650","DOIUrl":"https://doi.org/10.1166/ASEM.2020.2650","url":null,"abstract":"Nano-KIT consist of few standard chemicals (solvents)/constitutes that can be added sequentially by given protocol. Spherical silver (30 nm) and gold (25–30 nm) nanostructure were synthesized instantly in (5–10 min). Surface plasmon resonance for silver 413 nm and gold 545\u0000 nm were confirmed synthesis. Synthesized silver has stability more than 36 months in cold condition. Dynamic Light Scattering (DLS), X-ray Diffraction (XRD) and High Resolution-Transmission Electron Microscopy (HR-TEM) revealed 30 nm (silver) and 25–30 nm (gold). Nano-KIT can be used\u0000 for variety of application in Nano research areas like biomedical and industrial. Synthesized silver nanostructure were analysed with its molecular interaction between Bovine Serum Albumin (BSA). Biocompatibility assays with Red Blood Cells (RBC), number of binding sites, thermodynamic parameters\u0000 i.e., free energy, enthalpy and entropy were studied.","PeriodicalId":7213,"journal":{"name":"Advanced Science, Engineering and Medicine","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83724284","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":"Numerical Combustion Evaluation of Select Detailed Chemistry Mechanisms for Their Impact on Compression Ignition Diesel Engine Performance Prediction","authors":"Akash Dayal, M. Shrivastava, Rajiv Upadhyaya, L. S. Brar","doi":"10.1166/ASEM.2020.2670","DOIUrl":"https://doi.org/10.1166/ASEM.2020.2670","url":null,"abstract":"The study focuses on the selection of detailed chemistry model for numerical combustion of compression ignition diesel engine. Three different established chemical reaction mechanisms of different chemistry resolution are considered to predict the macro performance characteristics.\u0000 The numerical computation is performed on turbocharged 5.67L 130PS commercial vehicle diesel engine. The three chemical reactions mechanisms are used for engine performance prediction analysis viz. PSM Mechanism (having 121 species and 593 reactions), ERC Mech reaction mechanism model (having\u0000 61 species with 235 reactions) and Chalmers’ reaction mechanism model (having 42 species with 168 reactions) for analyses. The surrogate diesel fuel n-heptane is used in the combustion analysis. By making use of the three-chemistry model, conclusive results indicate significant\u0000 differences in the computational runtime without much loss in the accuracy of the performance characteristics (expressed as the indicated mean effective pressure (IMEP)).","PeriodicalId":7213,"journal":{"name":"Advanced Science, Engineering and Medicine","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74947547","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}