Pub Date : 2021-08-26DOI: 10.15587/1729-4061.2021.234174
I. Kartika, Kevin Kurnia, G. Senopati, J. Triwardono, B. Hermanto, F. Rokhmanto, M. S. Dwijaya, Alfirano Alfirano
Austenitic stainless steel is the most commonly used material in the production of orthopedic prostheses. In this study, AISI 430 SS (0.12 wt. % C; 1 wt. % Si; 1 wt. % Mn; 18 wt. % Cr; 0.04 wt. % P and 0.03 wt. % S) will be modified by creating austenite and removing its ferromagnetic properties via the high-temperature gas nitriding process. Cold rolling with various percentage reduction (30, 50, and 70 %) was followed by gas nitriding at a temperature of 1200 °C with holding times of 5, 7, and 9 hours, then quenching in water was carried out on as-annealed AISI 430 SS. The formation of the austenite phase was examined by XRD (x-ray diffraction). The microstructure and element dispersion were observed using SEM-EDS (scanning electron microscope-energy dispersive spectrometry), whereas the mechanical properties after gas nitriding and water quenching were determined by Vickers microhardness testing. At all stages of the gas nitriding process, the FCC iron indicated the austenite phase was visible on the alloy's surface, although the ferrite phase is still present. The intensity of austenite formation is produced by cold rolling 70 % reduction with a 5-hour gas nitriding time. Furthermore, the nitrogen layer was formed with a maximum thickness layer of approximately 3.14 µm after a 50 % reduction in cold rolling and 9 hours of gas nitriding process followed by water quenching. The hardness reached 600 HVN in this condition. This is due to the distribution of carbon that is concentrated on the surface. As the percent reduction in the cold rolling process increases, the strength of AISI 430 SS after gas nitriding can increase, causing an increase in the number of dislocations. The highest tensile strength and hardness of AISI 430 SS of 669 MPa and 271.83 HVN were obtained with a reduction of 70 %.
{"title":"The Effect of Cold Rolling and High-Temperature Gas Nitriding on Austenite Phase Formation in Aisi 430 SS","authors":"I. Kartika, Kevin Kurnia, G. Senopati, J. Triwardono, B. Hermanto, F. Rokhmanto, M. S. Dwijaya, Alfirano Alfirano","doi":"10.15587/1729-4061.2021.234174","DOIUrl":"https://doi.org/10.15587/1729-4061.2021.234174","url":null,"abstract":"Austenitic stainless steel is the most commonly used material in the production of orthopedic prostheses. In this study, AISI 430 SS (0.12 wt. % C; 1 wt. % Si; 1 wt. % Mn; 18 wt. % Cr; 0.04 wt. % P and 0.03 wt. % S) will be modified by creating austenite and removing its ferromagnetic properties via the high-temperature gas nitriding process. Cold rolling with various percentage reduction (30, 50, and 70 %) was followed by gas nitriding at a temperature of 1200 °C with holding times of 5, 7, and 9 hours, then quenching in water was carried out on as-annealed AISI 430 SS. The formation of the austenite phase was examined by XRD (x-ray diffraction). The microstructure and element dispersion were observed using SEM-EDS (scanning electron microscope-energy dispersive spectrometry), whereas the mechanical properties after gas nitriding and water quenching were determined by Vickers microhardness testing. At all stages of the gas nitriding process, the FCC iron indicated the austenite phase was visible on the alloy's surface, although the ferrite phase is still present. The intensity of austenite formation is produced by cold rolling 70 % reduction with a 5-hour gas nitriding time. Furthermore, the nitrogen layer was formed with a maximum thickness layer of approximately 3.14 µm after a 50 % reduction in cold rolling and 9 hours of gas nitriding process followed by water quenching. The hardness reached 600 HVN in this condition. This is due to the distribution of carbon that is concentrated on the surface. As the percent reduction in the cold rolling process increases, the strength of AISI 430 SS after gas nitriding can increase, causing an increase in the number of dislocations. The highest tensile strength and hardness of AISI 430 SS of 669 MPa and 271.83 HVN were obtained with a reduction of 70 %.","PeriodicalId":9858,"journal":{"name":"Chemical Engineering (Engineering) eJournal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88183814","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}
Natural superabsorbent polymers (SAP) based on cellulose and its derivatives are considered as the most abundant organic compounds which are derived from biomass. Biopolymer based superabsorbent including the polysaccharides based are economical and ecofriendly approach to many fields such as drug delivery, textiles, agricultural field, wastewater treatment, cosmetics etc. Polysaccharides especially cellulose, chitin and chitosan are important biopolymers because of their high abundance, renewability, wide distribution, biodegradability and low cost of production. The crosslinking and grafting of polysaccharides to produce hydrogels has several advantages as superabsorbent. Metal-based nanoparticles (NPs) have been used by the scientists in the fields of applied and fundamental research. Recently, polysaccharides are gaining importance as self-capping agents for synthesis of Ag NP. The paper provides a thorough review on recent developments on utilization of natural polysaccharide-based nanocomposite for various sorption applications. Specifically, their application and efficiency in organic drug delivery, antibacterial, dye removal, heavy metals removal, etc.
{"title":"Polysaccharide Based Superabsorbent Nanocomposite: A Review","authors":"Neetu Dabi, S. Divya","doi":"10.2139/ssrn.3904261","DOIUrl":"https://doi.org/10.2139/ssrn.3904261","url":null,"abstract":"Natural superabsorbent polymers (SAP) based on cellulose and its derivatives are considered as the most abundant organic compounds which are derived from biomass. Biopolymer based superabsorbent including the polysaccharides based are economical and ecofriendly approach to many fields such as drug delivery, textiles, agricultural field, wastewater treatment, cosmetics etc. Polysaccharides especially cellulose, chitin and chitosan are important biopolymers because of their high abundance, renewability, wide distribution, biodegradability and low cost of production. The crosslinking and grafting of polysaccharides to produce hydrogels has several advantages as superabsorbent. Metal-based nanoparticles (NPs) have been used by the scientists in the fields of applied and fundamental research. Recently, polysaccharides are gaining importance as self-capping agents for synthesis of Ag NP. The paper provides a thorough review on recent developments on utilization of natural polysaccharide-based nanocomposite for various sorption applications. Specifically, their application and efficiency in organic drug delivery, antibacterial, dye removal, heavy metals removal, etc.","PeriodicalId":9858,"journal":{"name":"Chemical Engineering (Engineering) eJournal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78849623","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}
S. Baik, Z. Mao, Qingqiang Ren, F. Xue, C. Campbell, Chuan Zhang, B. Zhou, R. Noebe, D. Seidman
The temporal evolution of ordered γ´(L12)-precipitates and the compositional trajectories during phase-separation of the γ(face-centered-cubic (f.c.c.))- and γ′(L12)-phases are studied in a Ni-0.10Al-0.085Cr-0.02Re (mole-fraction) superalloy, utilizing atom-probe tomography, transmission electron microscopy, and the Philippe-Voorhees (PV) coarsening model. As the γ′(L12)-precipitates grow, the excesses of Ni, Cr and Re, and depletion of Al in the γ(f.c.c.)-matrix develop as a result of diffusional fluxes crossing γ(f.c.c.)/γ′(L12) heterophase interfaces. The coupling effects on diffusional fluxes was introduced (PV coarsening model) in terms of the diffusion tensor, D, and the second-derivative tensor of the molar Gibbs free energies, G", obtained employing Thermo-Calc and DICTRA calculations. The Gibbs interfacial free energies, σγ/γ', are (16.9±3.4) mJ/m2 with all terms in D and G", which changes to (46.3±5.1) mJ/m2, (92.3±7.9) mJ/m2, and (-18.5±2.6) mJ/m2 without including the off-diagonal terms in D, G", and both D and G", respectively. The experimental APT compositional trajectories are displayed and compared with the PV model in a partial quaternary phase-diagram, employing a tetrahedron. The compositional trajectories measured by APT exhibit curvilinear behavior in the nucleation and growth regimes, t < 16 h, which become vectors, moving simultaneously toward the γ(f.c.c.) and γ′(L12) conjugate solvus-surfaces, for the quasi-stationary coarsening regime, t ≥ 16 h. The compositional trajectories for t ≥ 16 h are compared to the PV model with and without the off-diagonal terms in D and G". The directions including the off-diagonal terms in D and G" tensors are consistent with the APT experimental data.
{"title":"The Effects of Diffusional Couplings on Compositional Trajectories and Interfacial Free Energies During Phase Separation in a Quaternary Ni-Al-Cr-Re Model Superalloy","authors":"S. Baik, Z. Mao, Qingqiang Ren, F. Xue, C. Campbell, Chuan Zhang, B. Zhou, R. Noebe, D. Seidman","doi":"10.2139/ssrn.3919717","DOIUrl":"https://doi.org/10.2139/ssrn.3919717","url":null,"abstract":"The temporal evolution of ordered γ´(L12)-precipitates and the compositional trajectories during phase-separation of the γ(face-centered-cubic (f.c.c.))- and γ′(L12)-phases are studied in a Ni-0.10Al-0.085Cr-0.02Re (mole-fraction) superalloy, utilizing atom-probe tomography, transmission electron microscopy, and the Philippe-Voorhees (PV) coarsening model. As the γ′(L12)-precipitates grow, the excesses of Ni, Cr and Re, and depletion of Al in the γ(f.c.c.)-matrix develop as a result of diffusional fluxes crossing γ(f.c.c.)/γ′(L12) heterophase interfaces. The coupling effects on diffusional fluxes was introduced (PV coarsening model) in terms of the diffusion tensor, D, and the second-derivative tensor of the molar Gibbs free energies, G\", obtained employing Thermo-Calc and DICTRA calculations. The Gibbs interfacial free energies, σγ/γ', are (16.9±3.4) mJ/m2 with all terms in D and G\", which changes to (46.3±5.1) mJ/m2, (92.3±7.9) mJ/m2, and (-18.5±2.6) mJ/m2 without including the off-diagonal terms in D, G\", and both D and G\", respectively. The experimental APT compositional trajectories are displayed and compared with the PV model in a partial quaternary phase-diagram, employing a tetrahedron. The compositional trajectories measured by APT exhibit curvilinear behavior in the nucleation and growth regimes, t < 16 h, which become vectors, moving simultaneously toward the γ(f.c.c.) and γ′(L12) conjugate solvus-surfaces, for the quasi-stationary coarsening regime, t ≥ 16 h. The compositional trajectories for t ≥ 16 h are compared to the PV model with and without the off-diagonal terms in D and G\". The directions including the off-diagonal terms in D and G\" tensors are consistent with the APT experimental data.","PeriodicalId":9858,"journal":{"name":"Chemical Engineering (Engineering) eJournal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85894624","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}
Abstract Non-thermal effect caused by ultrafast lasers and swift ions in materials are very intriguing, which is of both scientific interest and technological importance. However, the underlying physics of non-thermal effect on ultrafast process remains unclear and the proposed mechanisms have been controversial. Based on the perturbation approximation under tight-binding theory, the non-thermal effect on tungsten (W) are extensively studied. We demonstrate that the non-thermal effect stemmed from the intense electronic excitations induce dramatic decrease in the melting point of W crystal, as well as non-thermal melting inside the W slab. Our analysis shows that the non-thermal forces are essentially responsible for the drop of melting point of the bulk system. Remarkably, the non-thermal effect combined with surface effect on a W film enhance the ordering of the direction of atomic motion near the surface, preventing melting near the surface area, but leading to non-thermal melting in the interior area of the film. Our work also exhibits a unified relationship between the non-thermal melting and the interatomic forces. This relationship is universal in metals and semiconductors irradiated by ultrafast lasers or swift ions, and has been well established long before.
{"title":"Non-Thermal Melting of Tungsten Under Intense Electronic Excitations","authors":"X. Ye, Zhihai He, Fei Gao, B. Pan","doi":"10.2139/ssrn.3831031","DOIUrl":"https://doi.org/10.2139/ssrn.3831031","url":null,"abstract":"Abstract Non-thermal effect caused by ultrafast lasers and swift ions in materials are very intriguing, which is of both scientific interest and technological importance. However, the underlying physics of non-thermal effect on ultrafast process remains unclear and the proposed mechanisms have been controversial. Based on the perturbation approximation under tight-binding theory, the non-thermal effect on tungsten (W) are extensively studied. We demonstrate that the non-thermal effect stemmed from the intense electronic excitations induce dramatic decrease in the melting point of W crystal, as well as non-thermal melting inside the W slab. Our analysis shows that the non-thermal forces are essentially responsible for the drop of melting point of the bulk system. Remarkably, the non-thermal effect combined with surface effect on a W film enhance the ordering of the direction of atomic motion near the surface, preventing melting near the surface area, but leading to non-thermal melting in the interior area of the film. Our work also exhibits a unified relationship between the non-thermal melting and the interatomic forces. This relationship is universal in metals and semiconductors irradiated by ultrafast lasers or swift ions, and has been well established long before.","PeriodicalId":9858,"journal":{"name":"Chemical Engineering (Engineering) eJournal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75545355","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}
Hanchen Feng, Linfeng Wang, S. Cui, N. Hansen, F. Fang, Xiaodan Zhang
Abstract Ultrastrong pure iron wires have been produced with a strength of 1.8 GPa with a strain of 10.35. Based on microstructural observation and quantified structural parameters, the strengthening mechanisms and strength-structure relationship have been analyzed. It is found that the fiber texture intensity, boundary spacing and boundary misorientation tend to saturation due to the boundary junction motion when the drawing strain exceeds 8.89. The dislocation density in the ferrite cells/lamellae increases to ~ 3.6 × 1015 m−2 at a drawing strain of 10.35 without saturation. Based on the systematic microstructural characterization and quantification, the d−1 or (2d)−0.5 boundary strengthening plus forest hardening are discussed.
{"title":"Microstructure and Strengthening Mechanisms of Nanolamellar Structures in Ultrastrong Drawn Iron Wires","authors":"Hanchen Feng, Linfeng Wang, S. Cui, N. Hansen, F. Fang, Xiaodan Zhang","doi":"10.2139/ssrn.3782839","DOIUrl":"https://doi.org/10.2139/ssrn.3782839","url":null,"abstract":"Abstract Ultrastrong pure iron wires have been produced with a strength of 1.8 GPa with a strain of 10.35. Based on microstructural observation and quantified structural parameters, the strengthening mechanisms and strength-structure relationship have been analyzed. It is found that the fiber texture intensity, boundary spacing and boundary misorientation tend to saturation due to the boundary junction motion when the drawing strain exceeds 8.89. The dislocation density in the ferrite cells/lamellae increases to ~ 3.6 × 1015 m−2 at a drawing strain of 10.35 without saturation. Based on the systematic microstructural characterization and quantification, the d−1 or (2d)−0.5 boundary strengthening plus forest hardening are discussed.","PeriodicalId":9858,"journal":{"name":"Chemical Engineering (Engineering) eJournal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83254493","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}
Pub Date : 2021-06-30DOI: 10.15587/2519-4852.2021.235980
E. Bezuglaya, I. Zinchenko, N. Lyapunov, Hanna S. Vlasenko, V. Musatov
The aim: The work is concerned with the substantiation of the approach to the identification and quantitative determination of ketoprofen macrogol 400 esters. Materials and methods: Ketoprofen, macrogol 400, ketoprofen macrogol 400 ester (KM400E), as well as model cream-gels were studied by the following methods: absorption spectrophotometry ultraviolet (UV) and visible, high-performance liquid chromatography (HPLC), gas chromatography (GC), GC / mass spectrometry, nuclear magnetic resonance (NMR) spectrometry and thermogravimetry. Results: It was found by GC and GC / mass spectrometry that the average molecular mass (Mr) of the test macrogol 400 is 383.50 and it contains oligomers with molecular masses from 150.17 to 546.65. KM400E, which is a mixture of esters of ketoprofen with macrogol oligomers, was synthesized. The formed esters were characterized by 1H NMR spectra. It was shown that the ratio of the average molecular mass of KM400E, calculated for monoesters, and the molecular mass of ketoprofen corresponds to the ratio of specific absorbances of solutions of ketoprofen and solutions of KM400E, this fact indicated the formation of monoesters. Taking into account the risk of variability of the fractional composition of macrogol 400 in different batches, it is advisable to quantify KM400E using ketoprofen reference standard (RS) and not KM400E RS. Using HPLC with diode array detection the peak of KM400E should be identified by the UV absorption spectrum with λmax≈255 nm, which is characteristic for ketoprofen, and the relative retention time (RRt) of the peak; KM400E should be quantified by the content of ketoprofen in this impurity. During storage of model cream-gels the content of KM400E impurity is significantly lower than the content of ketoprofen propylene glycol ester (mixture of isomers). Conclusions: The approach to the identification and quantitative determination of KM400E is substantiated. The analytical procedure for determination of KM400E impurity by HPLC with a diode array detection using ketoprofen RS was developed. Correctness of the procedure was proved by the results of the validation studies.
{"title":"Substantiation of an Approach to Determination of Ketoprofen Macrogol 400 Esters","authors":"E. Bezuglaya, I. Zinchenko, N. Lyapunov, Hanna S. Vlasenko, V. Musatov","doi":"10.15587/2519-4852.2021.235980","DOIUrl":"https://doi.org/10.15587/2519-4852.2021.235980","url":null,"abstract":"The aim: The work is concerned with the substantiation of the approach to the identification and quantitative determination of ketoprofen macrogol 400 esters. Materials and methods: Ketoprofen, macrogol 400, ketoprofen macrogol 400 ester (KM400E), as well as model cream-gels were studied by the following methods: absorption spectrophotometry ultraviolet (UV) and visible, high-performance liquid chromatography (HPLC), gas chromatography (GC), GC / mass spectrometry, nuclear magnetic resonance (NMR) spectrometry and thermogravimetry. Results: It was found by GC and GC / mass spectrometry that the average molecular mass (Mr) of the test macrogol 400 is 383.50 and it contains oligomers with molecular masses from 150.17 to 546.65. KM400E, which is a mixture of esters of ketoprofen with macrogol oligomers, was synthesized. The formed esters were characterized by 1H NMR spectra. It was shown that the ratio of the average molecular mass of KM400E, calculated for monoesters, and the molecular mass of ketoprofen corresponds to the ratio of specific absorbances of solutions of ketoprofen and solutions of KM400E, this fact indicated the formation of monoesters. Taking into account the risk of variability of the fractional composition of macrogol 400 in different batches, it is advisable to quantify KM400E using ketoprofen reference standard (RS) and not KM400E RS. Using HPLC with diode array detection the peak of KM400E should be identified by the UV absorption spectrum with λmax≈255 nm, which is characteristic for ketoprofen, and the relative retention time (RRt) of the peak; KM400E should be quantified by the content of ketoprofen in this impurity. During storage of model cream-gels the content of KM400E impurity is significantly lower than the content of ketoprofen propylene glycol ester (mixture of isomers). Conclusions: The approach to the identification and quantitative determination of KM400E is substantiated. The analytical procedure for determination of KM400E impurity by HPLC with a diode array detection using ketoprofen RS was developed. Correctness of the procedure was proved by the results of the validation studies.","PeriodicalId":9858,"journal":{"name":"Chemical Engineering (Engineering) eJournal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78456518","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}
Pub Date : 2021-06-25DOI: 10.15587/1729-4061.2021.229908
F. Yunita, E. Sulistiyono, N. Natasha, A. R. Rhamdani, F. Firdiyono, L. H. Lalasari, T. Arini, Enggar Setya Widyaningrum, E. Yustanti
Magnesium oxide (MgO) nanoparticles have been widely used in a variety of applications because of their good surface reactivity. Magnesium oxide from bittern has a larger surface area compared to magnesium oxide from calcined magnesite and magnesium ions precipitation from bittern using sodium hydroxide has higher purity than using calcium hydroxide or ammonium hydroxide. In this research, sodium hydroxide was added to a bittern solution obtaining magnesium hydroxide precipitate, followed by the calcination process to produce magnesium oxide. Nano magnesium oxide was synthesized by the ultrasonic destruction process using ethanol and 2-propanol as media. In this study, sonication time and particle concentration effect on the ultrasonic destruction process were investigated. During the process, the sonication time was varied between 8, 16, 32, 64, and 128 minutes while the magnesium oxide concentration was varied between 1 %, 2 %, and 3 %. Increasing sonication time and particle concentration will decrease the particle size. The previous study shows that particles with very small sizes tend to have an agglomeration effect. The aim of this work is to optimize nano magnesium oxide production from bittern. Surfactant addition was also studied to prevent agglomeration between particles. Four types of surfactant namely anionic (sodium lauryl sulfate), cationic (cetyl tri-methyl-ammonium bromide), amphoteric (fatty acid amido alkyl betaine), and non-ionic (nonylphenol 10 ethoxylated) with a concentration of 1 % and a volume of 0.125 ml were added during the second ultrasonic destruction process. All types of surfactants have a positive effect to prevent agglomeration during the ultrasonic destruction process, with the amphoteric surfactant having the highest performance
{"title":"Investigation of Surfactant Effect During Synthesis of Magnesium Oxide Nanoparticles From Bittern Using Ultrasonic Destruction Process","authors":"F. Yunita, E. Sulistiyono, N. Natasha, A. R. Rhamdani, F. Firdiyono, L. H. Lalasari, T. Arini, Enggar Setya Widyaningrum, E. Yustanti","doi":"10.15587/1729-4061.2021.229908","DOIUrl":"https://doi.org/10.15587/1729-4061.2021.229908","url":null,"abstract":"Magnesium oxide (MgO) nanoparticles have been widely used in a variety of applications because of their good surface reactivity. Magnesium oxide from bittern has a larger surface area compared to magnesium oxide from calcined magnesite and magnesium ions precipitation from bittern using sodium hydroxide has higher purity than using calcium hydroxide or ammonium hydroxide. In this research, sodium hydroxide was added to a bittern solution obtaining magnesium hydroxide precipitate, followed by the calcination process to produce magnesium oxide. Nano magnesium oxide was synthesized by the ultrasonic destruction process using ethanol and 2-propanol as media. In this study, sonication time and particle concentration effect on the ultrasonic destruction process were investigated. During the process, the sonication time was varied between 8, 16, 32, 64, and 128 minutes while the magnesium oxide concentration was varied between 1 %, 2 %, and 3 %. Increasing sonication time and particle concentration will decrease the particle size. The previous study shows that particles with very small sizes tend to have an agglomeration effect. The aim of this work is to optimize nano magnesium oxide production from bittern. Surfactant addition was also studied to prevent agglomeration between particles. Four types of surfactant namely anionic (sodium lauryl sulfate), cationic (cetyl tri-methyl-ammonium bromide), amphoteric (fatty acid amido alkyl betaine), and non-ionic (nonylphenol 10 ethoxylated) with a concentration of 1 % and a volume of 0.125 ml were added during the second ultrasonic destruction process. All types of surfactants have a positive effect to prevent agglomeration during the ultrasonic destruction process, with the amphoteric surfactant having the highest performance","PeriodicalId":9858,"journal":{"name":"Chemical Engineering (Engineering) eJournal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72991563","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}
Production of herbal product is not only a local business but also has global market opportunities. Therefore manufacturing with proven quality and consistency is an important aspect. The manufacturers should gain technological competence to ensure authenticity and efficacy, complying the quality and safety regulations, enhanced productivity and efficiency.
In the competitive market environment technology assessment is a tool which can be used in projecting future trajectories of technology as well as current performance level of the organization.
Out of the available models and frameworks for technological assessments, this study has used inputs from two models namely, the Technology Audit Model by Garcea – Areola and Outline of Innovation Management Audit by Tidd et al. these inputs have been used to develop a single model that can be effectively adaptable to herbal products industry.
There are two main objectives of the study. Firstly, develop a model which includes guide lines for technology assessment of the herbal products industry in Sri Lanka. Secondly, assessment of the level of technology position of LNP Ltd using the model and presenting recommendations for future improvements.
To accomplish the objectives, the study has identified five broad areas of technology, namely Technological Environment, Technological Strategy, Innovations and Technology Development, Technology Component and Technology Transfer, against which the LNP Ltd has been analyzed.
A check sheet to cover these elements has been used to guide through the assessment process. The elements using a three of the point scale ranging from High to Low (High -3, Low-1). The score of 3 for each element will represent the industry standard practice against which the other practices are measured.
{"title":"Technology Assessment of Herbal Products Industry in Sri Lanka","authors":"Niranga Silva, L. K. Perera, H. Perera","doi":"10.2139/ssrn.3868325","DOIUrl":"https://doi.org/10.2139/ssrn.3868325","url":null,"abstract":"Production of herbal product is not only a local business but also has global market opportunities. Therefore manufacturing with proven quality and consistency is an important aspect. The manufacturers should gain technological competence to ensure authenticity and efficacy, complying the quality and safety regulations, enhanced productivity and efficiency. <br><br>In the competitive market environment technology assessment is a tool which can be used in projecting future trajectories of technology as well as current performance level of the organization.<br><br>Out of the available models and frameworks for technological assessments, this study has used inputs from two models namely, the Technology Audit Model by Garcea – Areola and Outline of Innovation Management Audit by Tidd et al. these inputs have been used to develop a single model that can be effectively adaptable to herbal products industry. <br><br>There are two main objectives of the study. Firstly, develop a model which includes guide lines for technology assessment of the herbal products industry in Sri Lanka. Secondly, assessment of the level of technology position of LNP Ltd using the model and presenting recommendations for future improvements. <br><br>To accomplish the objectives, the study has identified five broad areas of technology, namely Technological Environment, Technological Strategy, Innovations and Technology Development, Technology Component and Technology Transfer, against which the LNP Ltd has been analyzed. <br><br>A check sheet to cover these elements has been used to guide through the assessment process. The elements using a three of the point scale ranging from High to Low (High -3, Low-1). The score of 3 for each element will represent the industry standard practice against which the other practices are measured. <br>","PeriodicalId":9858,"journal":{"name":"Chemical Engineering (Engineering) eJournal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90434871","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}
Pub Date : 2021-06-10DOI: 10.15587/1729-4061.2021.231917
A. Paliy, E. Aliiev, A. Nanka, O. Bogomolov, Vadim Bredixin, A. Paliy, O. Shkromada, Y. Musiienko, A. Stockiy, N. Grebenik
Many years of experience in the operation of milking machines show that milking rubber was and remains a short-lived and unreliable link in the technological process of machine milking. During operation, rubber quickly loses its strength and elastic properties, becomes stiff and less elastic, deforms, and changes its shape. The purpose of this study is to identify changes in the technical parameters of milking rubber under industrial conditions in order to establish their impact on the milking process. The obtained results could make it possible to rationally choose the milking rubber for teat cups, which would ensure an effective milking process. During this study’s initial stage, the physical and mechanical condition of milking rubber was experimentally established at steam disinfection and as a result of saturating the article with milk fats. The following stage implied detecting the effect of milking rubber tension in a teat cup on the speed of milking. It was established that milking rubber during operation is actively exposed to milk fat, which leads to the loss of its weight relative to its original value. On day 1,000 of work, the weight loss relative to the initial value (100 g), under the washing regime temperature of 85 °C, 50 °C, 35 °C, and 20 °C, was 1 g, 3.3 g, 5 g, and 4.2 g, respectively. The dependences have been derived for the swell mass of milking rubber M on the temperature of washing solutions T and the duration of operation t as a result of saturation with milk fats. The dependence of milk yield rate V on the tension force of milking rubber F in teat cups has been established. Thus, it was found that when the tension force of milking rubber changes from 25 to 60 N, the difference in the average intensity of milk yield is 0.13 kg/min (10.8 %). Regarding the amount of milk yield at the specified tension, the difference is 0.15 kg (2.5 %). At rubber tension from 60 to 25 N, the average milking time increases by 0.46 min (8.3 %). Thus, it was determined that a milking machine with milking rubber at different tension over a total milking time would unevenly milk different parts of the cow’s udder. The study reported here expands the idea about the technical and manufacturing characteristics of rubber articles, namely changes in them at steam disinfection and as a result of saturation with milk fats
{"title":"Identifying Changes in the Technical Parameters of Milking Rubber under Industrial Conditions to Elucidate Their Effect on the Milking Process","authors":"A. Paliy, E. Aliiev, A. Nanka, O. Bogomolov, Vadim Bredixin, A. Paliy, O. Shkromada, Y. Musiienko, A. Stockiy, N. Grebenik","doi":"10.15587/1729-4061.2021.231917","DOIUrl":"https://doi.org/10.15587/1729-4061.2021.231917","url":null,"abstract":"Many years of experience in the operation of milking machines show that milking rubber was and remains a short-lived and unreliable link in the technological process of machine milking. During operation, rubber quickly loses its strength and elastic properties, becomes stiff and less elastic, deforms, and changes its shape. The purpose of this study is to identify changes in the technical parameters of milking rubber under industrial conditions in order to establish their impact on the milking process. The obtained results could make it possible to rationally choose the milking rubber for teat cups, which would ensure an effective milking process. During this study’s initial stage, the physical and mechanical condition of milking rubber was experimentally established at steam disinfection and as a result of saturating the article with milk fats. The following stage implied detecting the effect of milking rubber tension in a teat cup on the speed of milking. It was established that milking rubber during operation is actively exposed to milk fat, which leads to the loss of its weight relative to its original value. On day 1,000 of work, the weight loss relative to the initial value (100 g), under the washing regime temperature of 85 °C, 50 °C, 35 °C, and 20 °C, was 1 g, 3.3 g, 5 g, and 4.2 g, respectively. The dependences have been derived for the swell mass of milking rubber M on the temperature of washing solutions T and the duration of operation t as a result of saturation with milk fats. The dependence of milk yield rate V on the tension force of milking rubber F in teat cups has been established. Thus, it was found that when the tension force of milking rubber changes from 25 to 60 N, the difference in the average intensity of milk yield is 0.13 kg/min (10.8 %). Regarding the amount of milk yield at the specified tension, the difference is 0.15 kg (2.5 %). At rubber tension from 60 to 25 N, the average milking time increases by 0.46 min (8.3 %). Thus, it was determined that a milking machine with milking rubber at different tension over a total milking time would unevenly milk different parts of the cow’s udder. The study reported here expands the idea about the technical and manufacturing characteristics of rubber articles, namely changes in them at steam disinfection and as a result of saturation with milk fats","PeriodicalId":9858,"journal":{"name":"Chemical Engineering (Engineering) eJournal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89806223","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}
Pub Date : 2021-06-10DOI: 10.15587/1729-4061.2021.232496
A. Narivskij, A. Nuradinov, I. Nuradinov
A method of physical modeling was applied to study the effect of external actions on the processes of crystallization and the formation of the structure of ingots. A brief review of existing hypotheses about the evolution of physical, structural, and chemical heterogeneities in large steel ingots is given. The parameters of the structure and the two-phase zone have been determined, as well as the nature of the distribution of segregated materials along the cross-section of ingots, depending on the conditions of their curing. The decisive importance of convective and capillary mass transfer in the interdendritic channels of hardening ingots on the formation of a zonal heterogeneity at their cross-section has been proven. Experimentally, when crystallizing a model environment (camphene), it has been visually confirmed that the flow of segregated materials in interdendritic channels occurs when a certain amount of impurities accumulates in them. A clear dependence of the speed of this flow on the rate of melt crystallization has been established. With an increase of the hardened part of the melt, the rate of segregated material movement (Vl) increases while the rate of crystallization (R) decreases due to worsening heat release conditions. At a certain distance from the ingot’s surface, these rates become equal, and impurities are carried to the curing border, which is the main cause of the formation of zonal segregation. The results reported here show that the evolution of zonal segregation in ingots can be controlled using various techniques involving external influence on the hardening melt. This study has demonstrated that the adjustable intensity of heat removal from an ingot, as well as the addition of external excess pressure on the hardening melt, could be used as such tools. In the study, to obtain ingots with a minimum level of chemical heterogeneity, it would suffice to provide the following conditions for the curing of the alloy: a value of the alloy crystallization speeds at the level of Rcr ≥ 9·10–2 mm/s, or external pressure on the free surface of ingots Рext. ≥ 135 kPa. The industrial implementation of the reported results could make it possible to improve the technology of obtaining large blacksmith ingots, provide savings in materials and energy resources, increase the yield of a suitable metal, and improve its quality.
{"title":"Devising Manufacturing Techniques To Control the Process of Zonal Segregation in Large Steel Ingots","authors":"A. Narivskij, A. Nuradinov, I. Nuradinov","doi":"10.15587/1729-4061.2021.232496","DOIUrl":"https://doi.org/10.15587/1729-4061.2021.232496","url":null,"abstract":"A method of physical modeling was applied to study the effect of external actions on the processes of crystallization and the formation of the structure of ingots. A brief review of existing hypotheses about the evolution of physical, structural, and chemical heterogeneities in large steel ingots is given. The parameters of the structure and the two-phase zone have been determined, as well as the nature of the distribution of segregated materials along the cross-section of ingots, depending on the conditions of their curing. The decisive importance of convective and capillary mass transfer in the interdendritic channels of hardening ingots on the formation of a zonal heterogeneity at their cross-section has been proven. Experimentally, when crystallizing a model environment (camphene), it has been visually confirmed that the flow of segregated materials in interdendritic channels occurs when a certain amount of impurities accumulates in them. A clear dependence of the speed of this flow on the rate of melt crystallization has been established. With an increase of the hardened part of the melt, the rate of segregated material movement (Vl) increases while the rate of crystallization (R) decreases due to worsening heat release conditions. At a certain distance from the ingot’s surface, these rates become equal, and impurities are carried to the curing border, which is the main cause of the formation of zonal segregation. The results reported here show that the evolution of zonal segregation in ingots can be controlled using various techniques involving external influence on the hardening melt. This study has demonstrated that the adjustable intensity of heat removal from an ingot, as well as the addition of external excess pressure on the hardening melt, could be used as such tools. In the study, to obtain ingots with a minimum level of chemical heterogeneity, it would suffice to provide the following conditions for the curing of the alloy: a value of the alloy crystallization speeds at the level of Rcr ≥ 9·10–2 mm/s, or external pressure on the free surface of ingots Рext. ≥ 135 kPa. The industrial implementation of the reported results could make it possible to improve the technology of obtaining large blacksmith ingots, provide savings in materials and energy resources, increase the yield of a suitable metal, and improve its quality.","PeriodicalId":9858,"journal":{"name":"Chemical Engineering (Engineering) eJournal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85666282","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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