Tarun Patodia, K. Sharma, Shalini Dixit, S. Katyayan, G. Agarwal, S. Jain, C. Saini, B. Tripathi
Lithium-sulphur batteries are one of the very appealing power sources with high energy density. In addition, sulfur (S) is also inexpensive, abundant, and nontoxic. Therefore, sulfur is a promising cathode material for high specific energy Li–S batteries. In this work, we used a low-cost and environmentally benign chemical reaction deposition strategy to immobilize sulfur on quasi two dimensional graphene oxides (GO) to prepare graphene oxide-sulfur (GO–S) and reduced-graphene oxide-sulfur (rGO–S) nanocomposite cathodes for Li–S batteries. The characterization of these composites have been performed by using X-ray diffraction (XRD), Field Emission Scanning Electron Microscope (FE-SEM), Transmission electron microscopy (TEM), and Fourier-transform infrared spectroscopy (FTIR) analysis. The XRD results reveals the orthorhombic crystalline structure of GO–S and rGO–S composites confirmed by diffraction peaks at 2θ = 22.90(222),25.90(026) and 28.00 (040). FT-IR spectra confirms bonding structure of composites. SEM and TEM images confirm interconnected network of GO–S and rGO–S composites having uniform surface morphology with particle size distribution 32–36 nm respectively.
{"title":"Physico-Chemical Analysis of GO-S and rGO-S Composites as Electrodes for Flexible Li-S Battery","authors":"Tarun Patodia, K. Sharma, Shalini Dixit, S. Katyayan, G. Agarwal, S. Jain, C. Saini, B. Tripathi","doi":"10.1166/ASEM.2020.2654","DOIUrl":"https://doi.org/10.1166/ASEM.2020.2654","url":null,"abstract":"Lithium-sulphur batteries are one of the very appealing power sources with high energy density. In addition, sulfur (S) is also inexpensive, abundant, and nontoxic. Therefore, sulfur is a promising cathode material for high specific energy Li–S batteries. In this work, we used\u0000 a low-cost and environmentally benign chemical reaction deposition strategy to immobilize sulfur on quasi two dimensional graphene oxides (GO) to prepare graphene oxide-sulfur (GO–S) and reduced-graphene oxide-sulfur (rGO–S) nanocomposite cathodes for Li–S batteries. The\u0000 characterization of these composites have been performed by using X-ray diffraction (XRD), Field Emission Scanning Electron Microscope (FE-SEM), Transmission electron microscopy (TEM), and Fourier-transform infrared spectroscopy (FTIR) analysis. The XRD results reveals the orthorhombic crystalline\u0000 structure of GO–S and rGO–S composites confirmed by diffraction peaks at 2θ = 22.90(222),25.90(026) and 28.00 (040). FT-IR spectra confirms bonding structure of composites. SEM and TEM images confirm interconnected network of GO–S and\u0000 rGO–S composites having uniform surface morphology with particle size distribution 32–36 nm respectively.","PeriodicalId":7213,"journal":{"name":"Advanced Science, Engineering and Medicine","volume":"10 1","pages":"1080-1083"},"PeriodicalIF":0.0,"publicationDate":"2020-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89947150","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}
In this study a FE model is prepared for drop weight impact hammer testing of polymeric syntactic foam. The foam is modelled using crushable foam material and hammer is modelled using bilinear material model of LS-DYNA®. A series of simulation is performed by varying density of foam and impact velocity of hammer. Based on the prepared FE model and the force-displacement relation, energy absorption of the foam is computed and compared for three densities and three velocities. A comparative study is presented based on the displacement, reaction force-time history, and forcedisplacement behaviour.
{"title":"Numerical Simulation of Low Impact Velocity Behaviour of Polymeric Syntactic Foam","authors":"Y. M. Chordiya, M. D. Goel","doi":"10.1166/ASEM.2020.2666","DOIUrl":"https://doi.org/10.1166/ASEM.2020.2666","url":null,"abstract":"In this study a FE model is prepared for drop weight impact hammer testing of polymeric syntactic foam. The foam is modelled using crushable foam material and hammer is modelled using bilinear material model of LS-DYNA®. A series of simulation is performed by varying density of\u0000 foam and impact velocity of hammer. Based on the prepared FE model and the force-displacement relation, energy absorption of the foam is computed and compared for three densities and three velocities. A comparative study is presented based on the displacement, reaction force-time history,\u0000 and forcedisplacement behaviour.","PeriodicalId":7213,"journal":{"name":"Advanced Science, Engineering and Medicine","volume":"104 1","pages":"1044-1049"},"PeriodicalIF":0.0,"publicationDate":"2020-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88413752","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}
The Mo–C blend composite coating was effectively developed with good surface morphology and enriched tribological properties using APS coating procedure for piston ring applications. The surface roughness values of composite coating maximum at 450 °C. The experimental result of Mo–C based coating shows that as the temperature varies from 30 to 450 °, COF decreases from 0.6 to 0.3, while specific wear rate was increased from 0.2 to 0.5 mm3/Nm. The increase in specific wear rate and decrease in COF may be attribute due to tribofilm formation on Mo blend composite coating.
{"title":"Effect of Temperature on Mo–C Blend Composite Coating for Piston Ring Applications","authors":"A. Tyagi, S. Pandey, Q. Murtaza, R. S. Walia","doi":"10.1166/ASEM.2020.2671","DOIUrl":"https://doi.org/10.1166/ASEM.2020.2671","url":null,"abstract":"The Mo–C blend composite coating was effectively developed with good surface morphology and enriched tribological properties using APS coating procedure for piston ring applications. The surface roughness values of composite coating maximum at 450 °C. The experimental result\u0000 of Mo–C based coating shows that as the temperature varies from 30 to 450 °, COF decreases from 0.6 to 0.3, while specific wear rate was increased from 0.2 to 0.5 mm3/Nm. The increase in specific wear rate and decrease in COF may be attribute due to tribofilm formation\u0000 on Mo blend composite coating.","PeriodicalId":7213,"journal":{"name":"Advanced Science, Engineering and Medicine","volume":"54 1","pages":"1077-1079"},"PeriodicalIF":0.0,"publicationDate":"2020-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86698656","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}
The present scenario is like that the need of the electrical energy is growing rapidly whereas the resource availability is lagging behind the load demand due to its extinction which leads to hinder our overall generation. It has been observed that the sustainable resources have great future potential to take lead to generate power and supply demand. In the present scenario there exists a few energy resources equivalent to fuel resource. So, there must be a technology to trap the waste and unutilized heat available in the atmosphere and utilize it into the form useful electrical energy. In the current situation, waste heat in the form of thermal energy is recovered and converted into conventional electrical energy. Today, 70% of produced energy in automobiles is wasted in form of heat by exhaust gases. The main outcome of this paper is to manage the waste heat is being generated in the vehicles efficiently, by introducing the concept of “Thermo Electric Generator” (TEG) which convert the waste heat produced inside the vehicles and Re-Generate in the form electric current and give it back to the “storage unit” due to “Seebeck effect” concept.
{"title":"Waste Heat Management System for Hybrid Vehicles Using Thermoelectric Generator","authors":"R. Asteekar, S. Selvan, R. Janani","doi":"10.1166/ASEM.2020.2669","DOIUrl":"https://doi.org/10.1166/ASEM.2020.2669","url":null,"abstract":"The present scenario is like that the need of the electrical energy is growing rapidly whereas the resource availability is lagging behind the load demand due to its extinction which leads to hinder our overall generation. It has been observed that the sustainable resources have great\u0000 future potential to take lead to generate power and supply demand. In the present scenario there exists a few energy resources equivalent to fuel resource. So, there must be a technology to trap the waste and unutilized heat available in the atmosphere and utilize it into the form useful electrical\u0000 energy. In the current situation, waste heat in the form of thermal energy is recovered and converted into conventional electrical energy. Today, 70% of produced energy in automobiles is wasted in form of heat by exhaust gases. The main outcome of this paper is to manage the waste heat is\u0000 being generated in the vehicles efficiently, by introducing the concept of “Thermo Electric Generator” (TEG) which convert the waste heat produced inside the vehicles and Re-Generate in the form electric current and give it back to the “storage unit” due to “Seebeck\u0000 effect” concept.","PeriodicalId":7213,"journal":{"name":"Advanced Science, Engineering and Medicine","volume":"33 1","pages":"1063-1066"},"PeriodicalIF":0.0,"publicationDate":"2020-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84689521","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}
The present investigation studied the dry sliding wear behavior of WC–Cu deposited ZE41A magnesium alloy under various parameters such as normal load, sliding speed and sliding time and the responses are wear rate and coefficient of friction. In this investigation, WC–Cu deposited magnesium alloy specimens were tested using pin on disc apparatus against EN31 steel disc. Wear mechanism map is developed for wear rate of the deposited magnesium alloy against normal load and sliding speed to identify the different wear modes such as mild, severe and ultra sever wear. Worn surface samples is assessed by Scanning Electron Microscope (SEM) and Energy Dispersive Spectroscope (EDS) to confirm the different wear mechanism such as abrasion, oxidation, delamination and melting. Normal load is identified as the most dominant process parameter in this experiment. Magnesium alloy deposited using WC–Cu composite coating by EDC improved the wear behavior in the lower ranges of sliding conditions.
{"title":"Wear Behavior of WC–Cu Deposited ZE41A Magnesium Alloy Using Wear Mechanism Map","authors":"U. Elaiyarasan, V. Satheeshkumar, C. Senthilkumar","doi":"10.1166/ASEM.2020.2640","DOIUrl":"https://doi.org/10.1166/ASEM.2020.2640","url":null,"abstract":"The present investigation studied the dry sliding wear behavior of WC–Cu deposited ZE41A magnesium alloy under various parameters such as normal load, sliding speed and sliding time and the responses are wear rate and coefficient of friction. In this investigation, WC–Cu\u0000 deposited magnesium alloy specimens were tested using pin on disc apparatus against EN31 steel disc. Wear mechanism map is developed for wear rate of the deposited magnesium alloy against normal load and sliding speed to identify the different wear modes such as mild, severe and ultra sever\u0000 wear. Worn surface samples is assessed by Scanning Electron Microscope (SEM) and Energy Dispersive Spectroscope (EDS) to confirm the different wear mechanism such as abrasion, oxidation, delamination and melting. Normal load is identified as the most dominant process parameter in this experiment.\u0000 Magnesium alloy deposited using WC–Cu composite coating by EDC improved the wear behavior in the lower ranges of sliding conditions.","PeriodicalId":7213,"journal":{"name":"Advanced Science, Engineering and Medicine","volume":"12 1","pages":"1028-1033"},"PeriodicalIF":0.0,"publicationDate":"2020-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86144011","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}
In the current paper, fructose–oxidase enzyme is used as stabilization medium due to its more efficiency, ability for more accurate controlling the enzyme reaction, protecting against wasting of enzyme as well as simple and easy use and exchange of enzyme medium after performing some levels of surface modification and developing multi–walled carbon nanotubes (MWCNTs) on Californium plate. For better connecting and stabilizing the enzyme on the medium, the prepared medium is washed by high concentration sulfuric acid and nitric acid and a large volume of deionized water and for protecting enzyme from devastating effect of Californium and prohibiting them to become inactive, surface is covered with cystamine before stabilization. Regarding the large size of fructose–oxidase enzyme compared to surface of medium, a connective material with amid at one end and pyrine at the other end is used as transfer agent and for stabilizing this connection, the prepared medium is placed into dimethylformamide (DMF) solution for a couple of hours. Activity of stabilized enzyme at 460 (nm) wavelength recorded by spectroscope was depicted against time to evaluate its stability in various times. The prepared medium, which have a large amount of fructose–oxidase enzyme, can be used as electrode in sensors. Furthermore, fructose–oxidase electrochemical sensor is one of the best methods for detecting low amount of fructose and applying Californium colloidal nanoparticles as a supplementary material in the structure of biosensor can be effective for progressing its efficiency and optimum efficiency. On the other hand, in the current study, electrode biosensor entitled as modified carbon paste electrode with Californium colloidal nanoparticles (Cfnano/CPE) is produced by carbon graphite powder, paraffin oil and Californium colloidal nanoparticles (24 nm) and it is compared with carbon paste electrode (CP). In semi–permeable membranes, a combination of 1 (ml) of 0.1 (M) phosphate buffer with specified pH and 10 (mg) of fructose–oxidase enzyme is placed around each electrode. In the same potential of 0.7 (V), biosensors are tested with fructose in concentration range of (0−1) (mM) and various amounts of pH (4,6,8) which lead to producing the maximum current and tracing fructose in pH=6 and concentration of 1 (M) as the optimum condition. Currentmetry induced from both biosensors are compared and it is confirmed that using Californium colloidal nanoparticles in the structure of (Cfnano/CPE) electrode leads to increasing the conductivity and currentmerty of biosensor. In addition, qualitative and quantitative measurement of food components is of great importance due to high cost of traditional methods, in addition to tendency for more accurate and sensitive detecting of these components. Fructose and triglycerides are such compounds that they frequently measure. Various methods are used to detect these food elements. However, the necessity for accurate measurement o
{"title":"Synthesis of Fructose Biosensors and Progressing Their Efficiency Using Californium Colloidal Nanoparticles for Detecting Fructose and Triglycerides","authors":"A. Heidari","doi":"10.1166/ASEM.2020.2635","DOIUrl":"https://doi.org/10.1166/ASEM.2020.2635","url":null,"abstract":"In the current paper, fructose–oxidase enzyme is used as stabilization medium due to its more efficiency, ability for more accurate controlling the enzyme reaction, protecting against wasting of enzyme as well as simple and easy use and exchange of enzyme medium after performing\u0000 some levels of surface modification and developing multi–walled carbon nanotubes (MWCNTs) on Californium plate. For better connecting and stabilizing the enzyme on the medium, the prepared medium is washed by high concentration sulfuric acid and nitric acid and a large volume of deionized\u0000 water and for protecting enzyme from devastating effect of Californium and prohibiting them to become inactive, surface is covered with cystamine before stabilization. Regarding the large size of fructose–oxidase enzyme compared to surface of medium, a connective material with amid at\u0000 one end and pyrine at the other end is used as transfer agent and for stabilizing this connection, the prepared medium is placed into dimethylformamide (DMF) solution for a couple of hours. Activity of stabilized enzyme at 460 (nm) wavelength recorded by spectroscope was depicted against time\u0000 to evaluate its stability in various times. The prepared medium, which have a large amount of fructose–oxidase enzyme, can be used as electrode in sensors. Furthermore, fructose–oxidase electrochemical sensor is one of the best methods for detecting low amount of fructose and applying\u0000 Californium colloidal nanoparticles as a supplementary material in the structure of biosensor can be effective for progressing its efficiency and optimum efficiency. On the other hand, in the current study, electrode biosensor entitled as modified carbon paste electrode with Californium colloidal\u0000 nanoparticles (Cfnano/CPE) is produced by carbon graphite powder, paraffin oil and Californium colloidal nanoparticles (24 nm) and it is compared with carbon paste electrode (CP). In semi–permeable membranes, a combination of 1 (ml) of 0.1 (M) phosphate buffer with specified pH and 10\u0000 (mg) of fructose–oxidase enzyme is placed around each electrode. In the same potential of 0.7 (V), biosensors are tested with fructose in concentration range of (0−1) (mM) and various amounts of pH (4,6,8) which lead to producing the maximum current and tracing fructose in pH=6\u0000 and concentration of 1 (M) as the optimum condition. Currentmetry induced from both biosensors are compared and it is confirmed that using Californium colloidal nanoparticles in the structure of (Cfnano/CPE) electrode leads to increasing the conductivity and currentmerty of biosensor. In addition,\u0000 qualitative and quantitative measurement of food components is of great importance due to high cost of traditional methods, in addition to tendency for more accurate and sensitive detecting of these components. Fructose and triglycerides are such compounds that they frequently measure. Various\u0000 methods are used to detect these food elements. However, the necessity for accurate measurement o","PeriodicalId":7213,"journal":{"name":"Advanced Science, Engineering and Medicine","volume":"14 1","pages":"1002-1017"},"PeriodicalIF":0.0,"publicationDate":"2020-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86606072","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}
A. Hekmat, Mojtaba Sadeghi Manesh, Z. Hajebrahimi, Shadie Hatamie
It has been believed that microgravity directly can modify the structure, function, and morphology of biosystems and numerous researches have been performed to recognize these alterations. Since histone H3 is an essential protein in the field of epigenetics, this research aimed to evaluate the effects of simulated microgravity on the human H3.3B (H3F3B) gene expression and histone H3 structure. The two-dimensional clinostat was applied for simulating microgravity. Analysis of the gene expression by real-time quantitative PCR revealed that simulated microgravity diminished the expression level of H3.3B considerably (P < 0.001). The UV-Visible absorption and extrinsic fluorescence emission results displayed that after 72 h of simulated microgravity the tertiary structure of histone H3 changed and the surface hydrophobicity of the protein incremented remarkably. Nevertheless, circular dichroism (CD) data showed that simulated microgravity did not perturb the secondary structure of histone H3. Collectively, microgravity can strictly affect the gene expression level of H3.3. Furthermore, histone H3 72 h after subjecting to simulated microgravity can exhibit a molten globule structure. The significance of this research lied in the fact that simulating microgravity can be an effective physical force in gene expression regulation and the protein folding process. This finding could help astrobiologists to realize major health risks for astronaut crews and space travelers and reduce these harmful effects. Furthermore, our observations can open fascinating research lines in astrobiology, biophysics, and exobiology.
{"title":"Microgravity-Induced Alterations in the H3.3B (H3F3B) Gene Expression and the Histone H3 Structure","authors":"A. Hekmat, Mojtaba Sadeghi Manesh, Z. Hajebrahimi, Shadie Hatamie","doi":"10.1166/ASEM.2020.2672","DOIUrl":"https://doi.org/10.1166/ASEM.2020.2672","url":null,"abstract":"It has been believed that microgravity directly can modify the structure, function, and morphology of biosystems and numerous researches have been performed to recognize these alterations. Since histone H3 is an essential protein in the field of epigenetics, this research aimed to evaluate\u0000 the effects of simulated microgravity on the human H3.3B (H3F3B) gene expression and histone H3 structure. The two-dimensional clinostat was applied for simulating microgravity. Analysis of the gene expression by real-time quantitative PCR revealed that simulated microgravity diminished the\u0000 expression level of H3.3B considerably (P < 0.001). The UV-Visible absorption and extrinsic fluorescence emission results displayed that after 72 h of simulated microgravity the tertiary structure of histone H3 changed and the surface hydrophobicity of the protein incremented remarkably.\u0000 Nevertheless, circular dichroism (CD) data showed that simulated microgravity did not perturb the secondary structure of histone H3. Collectively, microgravity can strictly affect the gene expression level of H3.3. Furthermore, histone H3 72 h after subjecting to simulated microgravity can\u0000 exhibit a molten globule structure. The significance of this research lied in the fact that simulating microgravity can be an effective physical force in gene expression regulation and the protein folding process. This finding could help astrobiologists to realize major health risks for astronaut\u0000 crews and space travelers and reduce these harmful effects. Furthermore, our observations can open fascinating research lines in astrobiology, biophysics, and exobiology.","PeriodicalId":7213,"journal":{"name":"Advanced Science, Engineering and Medicine","volume":"50 1","pages":"1084-1094"},"PeriodicalIF":0.0,"publicationDate":"2020-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86560242","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}
Nkosinathi Goodman Dlamini, A. Basson, Rajasekhar V. S. R. Pullabhotla
Iron, the most ubiquitous of the transition metals and the fourth most plentiful metal in the Earth’s crust, is the structural backbone of our modern infrastructure. It is therefore ironic that as a nanoparticle, iron has been somewhat neglected in favour of its own oxides as well as other metals such as cobalt, nickel, gold, and platinum. This study reports the green synthesis of iron nanoparticles using a bioflocculant and their characterization. The as-synthesised materials were characterized using Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FT-IR), Thermogravimetric analysis (TGA) and UV-Vis absorption spectroscopy. Spherical morphology was observed for the as-synthesised iron nanoparticles (FeNPs) and elemental analysis indicated iron with 17.31%. XRD studies revealed the broader peaks at 24°, 29°, 30°, and 35° 2θ for the as-synthesised iron nanoparticles indicating the nano sized particles. FT-IR spectra showed the bands at 3154 cm-1 (bioflocculant) and 3244 cm-1 (iron nanoparticles) representing the presence of hydroxyl (–OH) and amine (–NH2) functional groups.
{"title":"Green Synthesis of Iron Nanoparticles by a Polysaccharide Bioflocculant from Marine Alcaligenes faecalis HCB2 and Characterization","authors":"Nkosinathi Goodman Dlamini, A. Basson, Rajasekhar V. S. R. Pullabhotla","doi":"10.1166/ASEM.2020.2637","DOIUrl":"https://doi.org/10.1166/ASEM.2020.2637","url":null,"abstract":"Iron, the most ubiquitous of the transition metals and the fourth most plentiful metal in the Earth’s crust, is the structural backbone of our modern infrastructure. It is therefore ironic that as a nanoparticle, iron has been somewhat neglected in favour of its own oxides as\u0000 well as other metals such as cobalt, nickel, gold, and platinum. This study reports the green synthesis of iron nanoparticles using a bioflocculant and their characterization. The as-synthesised materials were characterized using Scanning Electron Microscopy (SEM), Transmission Electron Microscopy\u0000 (TEM), X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FT-IR), Thermogravimetric analysis (TGA) and UV-Vis absorption spectroscopy. Spherical morphology was observed for the as-synthesised iron nanoparticles (FeNPs) and elemental analysis indicated iron with 17.31%. XRD studies\u0000 revealed the broader peaks at 24°, 29°, 30°, and 35° 2θ for the as-synthesised iron nanoparticles indicating the nano sized particles. FT-IR spectra showed the bands at 3154 cm-1 (bioflocculant) and 3244 cm-1 (iron nanoparticles) representing the\u0000 presence of hydroxyl (–OH) and amine (–NH2) functional groups.","PeriodicalId":7213,"journal":{"name":"Advanced Science, Engineering and Medicine","volume":"13 1","pages":"1034-1039"},"PeriodicalIF":0.0,"publicationDate":"2020-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90495535","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}
Evani Ferreira Cardoso, A. Albuquerque, A. M. J. C. Neto, G. S. Mota, F. L. Costa
Recently, several users of nuclear magnetic resonance spectroscopy have considered the employing of quantum chemical methods in the spectra predictions, since these methods are now well developed and implemented in popular program packages. Based on the experience of our group, the purpose of this article is to test the feasibility in the generating of a scaling factor for hydrogen-1 chemical shifts calculations at the GIAO-mPW1PW91/6-31G(d)//mPW1PW91/6-31G(d) level of theory in gas phase to assist in the determination of organic molecule structures. It is important to highlight that our level of theory requires low computational time, consequently it can be used even in personal computers. We used 80 organic molecules to yield a scaling factor equation: scaled chemical is equal to 0.98 (calculated chemical shift)+0.09, (calculated tetramethylsilane value of 32.26 parts per million). The test molecule is oleana-12(13), 15(16)-dienoic acid, a triterpene with a complex structure, and with various biological and pharmacological applications. The error values of root mean square were slightly higher for the triterpene molecule compared to the 80 molecules (1.40 percent and 1.53 percent, respectively. We believe that this was due to the greater flexibility of the triterpene molecule. Thus, taking into consideration the cost-effectiveness ratio, the 1H NMR calculations at the GIAO-mPW1PW91/6-31G(d)//mPW1PW91/6-31G(d) level of theory have produced promissory results.
{"title":"Gauge-Including-Atomic-Orbitals-mPW1PW91/6-31G(d) Scaling Factor as a Satisfactory Cost-Effectiveness Ratio for H-1 Nuclear Magnetic Resonance Chemical Shift Calculations","authors":"Evani Ferreira Cardoso, A. Albuquerque, A. M. J. C. Neto, G. S. Mota, F. L. Costa","doi":"10.1166/ASEM.2020.2652","DOIUrl":"https://doi.org/10.1166/ASEM.2020.2652","url":null,"abstract":"Recently, several users of nuclear magnetic resonance spectroscopy have considered the employing of quantum chemical methods in the spectra predictions, since these methods are now well developed and implemented in popular program packages. Based on the experience of our group, the\u0000 purpose of this article is to test the feasibility in the generating of a scaling factor for hydrogen-1 chemical shifts calculations at the GIAO-mPW1PW91/6-31G(d)//mPW1PW91/6-31G(d) level of theory in gas phase to assist in the determination of organic molecule structures. It is important\u0000 to highlight that our level of theory requires low computational time, consequently it can be used even in personal computers. We used 80 organic molecules to yield a scaling factor equation: scaled chemical is equal to 0.98 (calculated chemical shift)+0.09, (calculated tetramethylsilane value\u0000 of 32.26 parts per million). The test molecule is oleana-12(13), 15(16)-dienoic acid, a triterpene with a complex structure, and with various biological and pharmacological applications. The error values of root mean square were slightly higher for the triterpene molecule compared to the 80\u0000 molecules (1.40 percent and 1.53 percent, respectively. We believe that this was due to the greater flexibility of the triterpene molecule. Thus, taking into consideration the cost-effectiveness ratio, the 1H NMR calculations at the GIAO-mPW1PW91/6-31G(d)//mPW1PW91/6-31G(d) level of theory\u0000 have produced promissory results.","PeriodicalId":7213,"journal":{"name":"Advanced Science, Engineering and Medicine","volume":"54 1","pages":"1095-1101"},"PeriodicalIF":0.0,"publicationDate":"2020-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80847592","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}
Agnes Jalowitzki Silva, Thaís Forest Giacomello, G. S. Mota, Antonio M. J. Chaves, F. L. Costa
Chalcones exhibit a wide variety of beneficial biological activities. In addition, these compounds include the prevention of diseases related to oxidative stress. The structural characterization of these molecules by means of analytical techniques can become a difficult task due to the complexity of some structures. However, cases of erroneously established natural product structure review are still found in the literature despite recent advances in spectroscopic techniques. Therefore, it is necessary to develop quantum calculation protocols that can aid in the correct structural ascertainment of these compounds. Thus, in this work, we tried to develop a parameterized protocol for calculations of chemical shift of carbon-13 nuclear magnetic resonance, in order to ensure a correct structural determination of polyphenols, with a focus on chalcones. For this, a series of molecules belonging to this class, with complex and varied structural skeletons, reliably elucidated in the literature, was selected and subjected to stochastic conformational searches using the Monte Carlo method and the Merk molecular force filed. The lower energy conformations of each molecule were selected for the geometry optimization step, performed at the mPW1PW91/6-31G(d) level. The chemical shifts of carbon-13 were calculated at the same level of theory, taking into account the population distribution of Boltzmann. The calculations were affected in both liquid phases, using the Polarizable Continuous Model as an implicit solvation model. The results show that the level of theory applied in the liquid phase allows a good reproduction of the experimental data. The application of the scaling factor allows the cancellation of systematic errors, which means that the values of scaled chemical shift are closer to the experimental ones. Thus, the parameterized protocol proved to be an important tool for the structural elucidation of polyphenols by calculations of carbon-13 nuclear magnetic resonance chemical shifts.
{"title":"An Application of the Polarizable Continnum Model for Obtaining Chalcones Magnetic Properties","authors":"Agnes Jalowitzki Silva, Thaís Forest Giacomello, G. S. Mota, Antonio M. J. Chaves, F. L. Costa","doi":"10.1166/asem.2020.2631","DOIUrl":"https://doi.org/10.1166/asem.2020.2631","url":null,"abstract":"Chalcones exhibit a wide variety of beneficial biological activities. In addition, these compounds include the prevention of diseases related to oxidative stress. The structural characterization of these molecules by means of analytical techniques can become a difficult task due to\u0000 the complexity of some structures. However, cases of erroneously established natural product structure review are still found in the literature despite recent advances in spectroscopic techniques. Therefore, it is necessary to develop quantum calculation protocols that can aid in the correct\u0000 structural ascertainment of these compounds. Thus, in this work, we tried to develop a parameterized protocol for calculations of chemical shift of carbon-13 nuclear magnetic resonance, in order to ensure a correct structural determination of polyphenols, with a focus on chalcones. For this,\u0000 a series of molecules belonging to this class, with complex and varied structural skeletons, reliably elucidated in the literature, was selected and subjected to stochastic conformational searches using the Monte Carlo method and the Merk molecular force filed. The lower energy conformations\u0000 of each molecule were selected for the geometry optimization step, performed at the mPW1PW91/6-31G(d) level. The chemical shifts of carbon-13 were calculated at the same level of theory, taking into account the population distribution of Boltzmann. The calculations were affected in both liquid\u0000 phases, using the Polarizable Continuous Model as an implicit solvation model. The results show that the level of theory applied in the liquid phase allows a good reproduction of the experimental data. The application of the scaling factor allows the cancellation of systematic errors, which\u0000 means that the values of scaled chemical shift are closer to the experimental ones. Thus, the parameterized protocol proved to be an important tool for the structural elucidation of polyphenols by calculations of carbon-13 nuclear magnetic resonance chemical shifts.","PeriodicalId":7213,"journal":{"name":"Advanced Science, Engineering and Medicine","volume":"78 1","pages":"939-950"},"PeriodicalIF":0.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80449521","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}
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