A. Laksono, T. A. Amatosa, Hilda Pebrianti Octaviana Sitorus, Wentika Putri Kusuma Asih, S. Sulistijono
Hydroxyapatite (HAp) is one of the constituent minerals of bone and teeth, that has been widely used for synthesizing bone graft. Due to the limitation on properties of the hydroxyapatite, it is doping with Magnesium (HAp-Mg). The addition of Chitosan (Chi) was expected to improve the antibacterial properties of HAp-Mg. The present research aims to study the influence of Chitosan with 0, 5, 15, and 25 wt% addition on biocompatibility properties of Chi/HAp-Mg composite. HAp-Mg was synthesized using the sol-gel method; meanwhile, Chi/HAp-Mg composite was manufactured by mixing Chitosan in acetic acid, and HAp-Mg was added into the mixture. The synthesized samples were characterized using XRD and SEM. In vitro antibacterial activities of the Chi/HAp-Mg composite were evaluated against Escherichia coli bacteria. Biocompatibility analysis from antibacterial activity showed that composite with the optimal composition on the addition of 15 wt% Chitosan has the best ability in inhibiting the growth of E. coli bacteria.
{"title":"Study on Antibacterial of Chitosan/Hydroxyapatite Doped Magnesium Composite as a Material for Bone Graft Applications","authors":"A. Laksono, T. A. Amatosa, Hilda Pebrianti Octaviana Sitorus, Wentika Putri Kusuma Asih, S. Sulistijono","doi":"10.7454/mst.v23i3.3755","DOIUrl":"https://doi.org/10.7454/mst.v23i3.3755","url":null,"abstract":"Hydroxyapatite (HAp) is one of the constituent minerals of bone and teeth, that has been widely used for synthesizing bone graft. Due to the limitation on properties of the hydroxyapatite, it is doping with Magnesium (HAp-Mg). The addition of Chitosan (Chi) was expected to improve the antibacterial properties of HAp-Mg. The present research aims to study the influence of Chitosan with 0, 5, 15, and 25 wt% addition on biocompatibility properties of Chi/HAp-Mg composite. HAp-Mg was synthesized using the sol-gel method; meanwhile, Chi/HAp-Mg composite was manufactured by mixing Chitosan in acetic acid, and HAp-Mg was added into the mixture. The synthesized samples were characterized using XRD and SEM. In vitro antibacterial activities of the Chi/HAp-Mg composite were evaluated against Escherichia coli bacteria. Biocompatibility analysis from antibacterial activity showed that composite with the optimal composition on the addition of 15 wt% Chitosan has the best ability in inhibiting the growth of E. coli bacteria.","PeriodicalId":22842,"journal":{"name":"Theory of Computing Systems \\/ Mathematical Systems Theory","volume":"7 1","pages":"119-125"},"PeriodicalIF":0.0,"publicationDate":"2020-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75508701","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}
Magnetic resonance imaging (MRI) is an essential medical imaging technique which is widely used for medical research and diagnosis. Dynamic MRI provides the observed object visualization through time and results in a spatiotemporal signal. The image sequences often contain redundant information in both spatial and temporal domains. To utilize this characteristic, we propose a spatio-temporal reconstruction approach based on compressive sensing theory. We apply spatio-temporal structure tensor using nuclear norm, in addition to the wavelet sparsity regularization. The spatio-temporal structure tensor is a matrix that consists of gradient components of the MRI data w.r.t the spatial and temporal domains. For the wavelet sparsity, we use L1 – L2 instead of L1 norm. We propose the algorithm using primaldual splitting (PDS) approach to solve the convex optimization problem. In the experiment, we investigate the potential benefit of adding the two regularizations to the compressive sensing problem. The algorithm is compared with PDSbased algorithm using conventional regularizations, i.e., wavelet sparsity and total variation. Our proposed algorithm performs superior results in terms of reconstruction accuracy and visual quality.
{"title":"Evaluation of Primal-Dual Splitting Algorithm for MRI Reconstruction Using Spatio-Temporal Structure Tensor and L1-2 Norm","authors":"M. Rizkinia, M. Okuda","doi":"10.7454/mst.v23i3.3892","DOIUrl":"https://doi.org/10.7454/mst.v23i3.3892","url":null,"abstract":"Magnetic resonance imaging (MRI) is an essential medical imaging technique which is widely used for medical research and diagnosis. Dynamic MRI provides the observed object visualization through time and results in a spatiotemporal signal. The image sequences often contain redundant information in both spatial and temporal domains. To utilize this characteristic, we propose a spatio-temporal reconstruction approach based on compressive sensing theory. We apply spatio-temporal structure tensor using nuclear norm, in addition to the wavelet sparsity regularization. The spatio-temporal structure tensor is a matrix that consists of gradient components of the MRI data w.r.t the spatial and temporal domains. For the wavelet sparsity, we use L1 – L2 instead of L1 norm. We propose the algorithm using primaldual splitting (PDS) approach to solve the convex optimization problem. In the experiment, we investigate the potential benefit of adding the two regularizations to the compressive sensing problem. The algorithm is compared with PDSbased algorithm using conventional regularizations, i.e., wavelet sparsity and total variation. Our proposed algorithm performs superior results in terms of reconstruction accuracy and visual quality.","PeriodicalId":22842,"journal":{"name":"Theory of Computing Systems \\/ Mathematical Systems Theory","volume":"17 1","pages":"126-130"},"PeriodicalIF":0.0,"publicationDate":"2020-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84622536","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}
M. Silalahi, Hanif Abdurrahman Wicaksana, F. Aziz, S. Ahda, M. R. Iskandar
Micropowders of oxide-dispersion-strengthened (ODS) steel have been synthesized using the ultrasonic irradiation method with variations in amplitude. The ultrasonic irradiation process is performed for 50 h at a frequency of 20 kHz with 40%, 50%, and 60% amplitudes in toluene solution. The formation of Fe-Cr microalloys in the preparation of Fe15Cr-0.5Y2O3 powder was analyzed using SEM-EDS, X-ray diffraction (XRD), and TEM-EDS. The percentage of FeCr phase mass fraction of ODS steel micropowder formed during ultrasonic irradiation with 40%:50%:60% amplitude was 12.2%:34.1%:22.1%, with 25.67:77.02:38.51 nm crystallite size. The crystallite size at 50% amplitude was the largest, and the diffusion process of Fe-Cr-Y2O3 microparticles was most dominant at 50% amplitude. The Fe and Cr phases are still present when the ODS particles successfully dispersed in the main particle.
{"title":"A New Synthesized Microalloys Steel ODS of High Amplitude Ultrasonically Irradiation","authors":"M. Silalahi, Hanif Abdurrahman Wicaksana, F. Aziz, S. Ahda, M. R. Iskandar","doi":"10.7454/mst.v23i3.3880","DOIUrl":"https://doi.org/10.7454/mst.v23i3.3880","url":null,"abstract":"Micropowders of oxide-dispersion-strengthened (ODS) steel have been synthesized using the ultrasonic irradiation method with variations in amplitude. The ultrasonic irradiation process is performed for 50 h at a frequency of 20 kHz with 40%, 50%, and 60% amplitudes in toluene solution. The formation of Fe-Cr microalloys in the preparation of Fe15Cr-0.5Y2O3 powder was analyzed using SEM-EDS, X-ray diffraction (XRD), and TEM-EDS. The percentage of FeCr phase mass fraction of ODS steel micropowder formed during ultrasonic irradiation with 40%:50%:60% amplitude was 12.2%:34.1%:22.1%, with 25.67:77.02:38.51 nm crystallite size. The crystallite size at 50% amplitude was the largest, and the diffusion process of Fe-Cr-Y2O3 microparticles was most dominant at 50% amplitude. The Fe and Cr phases are still present when the ODS particles successfully dispersed in the main particle.","PeriodicalId":22842,"journal":{"name":"Theory of Computing Systems \\/ Mathematical Systems Theory","volume":"1 1","pages":"111-118"},"PeriodicalIF":0.0,"publicationDate":"2020-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88557790","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}
P. Parikin, M. Dani, R. Iskandar, A. K. Jahja, A. Insani, J. Mayer
The field of physical metallurgy is one of the primary beacons that guide alloy developments for multipurpose materials such as the in-core structure materials for pressure vessel components and heat exchangers. The surface microstructure of new ferritic steel with significant local constituent materials was characterized by high resolution powder neutron diffractometer (HRPD) and transmission electron microscope (TEM), combined with the energy dispersive X-ray spectroscopy (EDX). The alloy contains73% Fe, 24% Cr, 2% Si, 0.8% Mn, and 0.1% Ni, in %wt. The charge materials were melted by the casting techniques. The neutron diffractograms obtained shows five dominant diffraction peaks at (110), (200), (211), and (220) reflection planes, which is a typical structure for a body centered tetragonal system. The pattern also included some unidentified peaks which were verified to be Al2O3.54SiO2, Cr23C6, and SiC crystals. A piece of alloy which taken from the middle of the ferritic ingots was also characterized by the HRPD; no unidentified peaks were observed. Results from the scanning transmission electron microscopy (STEM) combined with EDX analyses confirmed the neutron identified phase distributions. Also, oxides and carbides were observed to form mainly close to the surface of the steel. Cracks and pores which probably formed during the preparations were also identified close to the surface. Although the ferritic steel was successfully synthesized and characterized, some unidentified phases and defects could still be found in the produced ingots.
{"title":"Comprehensive Inspection on the Experimental Ferritic Stainless Steel by Means of Transmission Electron Microscopy and Neutron Diffraction Techniques","authors":"P. Parikin, M. Dani, R. Iskandar, A. K. Jahja, A. Insani, J. Mayer","doi":"10.7454/mst.v23i3.3746","DOIUrl":"https://doi.org/10.7454/mst.v23i3.3746","url":null,"abstract":"The field of physical metallurgy is one of the primary beacons that guide alloy developments for multipurpose materials such as the in-core structure materials for pressure vessel components and heat exchangers. The surface microstructure of new ferritic steel with significant local constituent materials was characterized by high resolution powder neutron diffractometer (HRPD) and transmission electron microscope (TEM), combined with the energy dispersive X-ray spectroscopy (EDX). The alloy contains73% Fe, 24% Cr, 2% Si, 0.8% Mn, and 0.1% Ni, in %wt. The charge materials were melted by the casting techniques. The neutron diffractograms obtained shows five dominant diffraction peaks at (110), (200), (211), and (220) reflection planes, which is a typical structure for a body centered tetragonal system. The pattern also included some unidentified peaks which were verified to be Al2O3.54SiO2, Cr23C6, and SiC crystals. A piece of alloy which taken from the middle of the ferritic ingots was also characterized by the HRPD; no unidentified peaks were observed. Results from the scanning transmission electron microscopy (STEM) combined with EDX analyses confirmed the neutron identified phase distributions. Also, oxides and carbides were observed to form mainly close to the surface of the steel. Cracks and pores which probably formed during the preparations were also identified close to the surface. Although the ferritic steel was successfully synthesized and characterized, some unidentified phases and defects could still be found in the produced ingots.","PeriodicalId":22842,"journal":{"name":"Theory of Computing Systems \\/ Mathematical Systems Theory","volume":"22 1","pages":"103-110"},"PeriodicalIF":0.0,"publicationDate":"2020-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74235697","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 : 2019-12-01DOI: 10.13189/MST.2019.060201
Mahbubur Rahman, A. Asif, P. Sarker, B. Sarker
This research work was endeavored to improve tensile strength of viscose woven fabric by using chemical finishes like water repellent finishes with cross linking agent and softener. In this work, 100% viscose woven fabric was used and different types of samples were prepared by treating water repellent finishes, cross linking agent and softeners. The sample was investigated by tensile strength test (ASTM D5034), spray test (AATCC–22), water vapor test (cup method) and moisture regain test (ASTM D2495 oven dry method). Eight types of recipes were used in this research. For the variation of C6-fluorocarbon the sample code-B (C6-fluorocarbon 60g/l, cross-linking agent 15 g/l and softener 10g/l) showed better result in tensile strength and water spray test. Taking the amount of C6-fluorocarbon (60g/l) as constant and making variation cross linking agent which reached a conclusion that, sample-B1 (C6-fluorocarbon 60g/l, cross-linking agent 05g/l and softener 10g/l) showed better result for wet tensile strength, water spray test and moisture regain but showed less water vapor permeability. From this experiment it was evident that recipe which belongs to sample code B1 is suitable for improving the tensile strength of viscose fabric.
{"title":"Improvement of Tensile Strength of Viscose Woven Fabric by Applying Chemical Finishes","authors":"Mahbubur Rahman, A. Asif, P. Sarker, B. Sarker","doi":"10.13189/MST.2019.060201","DOIUrl":"https://doi.org/10.13189/MST.2019.060201","url":null,"abstract":"This research work was endeavored to improve tensile strength of viscose woven fabric by using chemical finishes like water repellent finishes with cross linking agent and softener. In this work, 100% viscose woven fabric was used and different types of samples were prepared by treating water repellent finishes, cross linking agent and softeners. The sample was investigated by tensile strength test (ASTM D5034), spray test (AATCC–22), water vapor test (cup method) and moisture regain test (ASTM D2495 oven dry method). Eight types of recipes were used in this research. For the variation of C6-fluorocarbon the sample code-B (C6-fluorocarbon 60g/l, cross-linking agent 15 g/l and softener 10g/l) showed better result in tensile strength and water spray test. Taking the amount of C6-fluorocarbon (60g/l) as constant and making variation cross linking agent which reached a conclusion that, sample-B1 (C6-fluorocarbon 60g/l, cross-linking agent 05g/l and softener 10g/l) showed better result for wet tensile strength, water spray test and moisture regain but showed less water vapor permeability. From this experiment it was evident that recipe which belongs to sample code B1 is suitable for improving the tensile strength of viscose fabric.","PeriodicalId":22842,"journal":{"name":"Theory of Computing Systems \\/ Mathematical Systems Theory","volume":"49 1","pages":"23-30"},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85603320","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 : 2019-01-01DOI: 10.37099/MTU.DC.ETDR/839
Nick Videtich
{"title":"Laser Induced Phase Transformations and Fluorescence Measurements from Nanodiamond Particles","authors":"Nick Videtich","doi":"10.37099/MTU.DC.ETDR/839","DOIUrl":"https://doi.org/10.37099/MTU.DC.ETDR/839","url":null,"abstract":"","PeriodicalId":22842,"journal":{"name":"Theory of Computing Systems \\/ Mathematical Systems Theory","volume":"70 1","pages":"2"},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73303446","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 DUAL-NANOSTRUCTURED APPROACH TO SERS AMENABLE TO LARGE-SCALE PRODUCTION Kory Brian Castro Old Dominion University, 2019 Director: Dr. John Cooper A SERS device was made using a dual-nanostructured surface comprised of silver nanoparticle and silver nanowires. The ability of each nanostructure to produce a uniform surface was characterized and the surface-enhanced Raman scattering (SERS) response of the resulting surfaces were examined using the reporter molecule 4aminothiolphenol (ATP) and a 638 nm excitation laser. A synthetic method was developed to produce silver nanowires with lengths of ~20 μm and diameters of ~100 nm with a narrow size distribution. The method utilized a simple, one-pot synthesis that is amenable to large-scale production. A selective precipitation method was used to the isolate the ~200 aspect ratio silver nanowires in a high purity. The wires were Mayer rod coated onto glass slides to produce uniform surfaces with ease. The SERS response was found to be highly variable depending on the sampled location. An enhancement factor of 2.2x105 was tentatively assigned using the 1600 cm-1 peak of ATP. The silver complex μ-oxolato-bis(ethylenediaminesilver(I)) was synthesized as reported in the literature. The aqueous solution of the complex was thermally decomposed to produce SERS-active silver surfaces on glass slides. The silver complex was unable to generate a uniform surface coating without the use of additives. By dropcasting the complex at the decomposition temperature, surfaces were generated exhibiting ~75 nm, spherical nanoparticles. The surface was found to be SERS-active, however the poor processing characteristics of the complex prevent its applicability to large-scale device production. Silver nanowire surfaces were used as substrates to Mayer rod coat the silver complex uniformly without the use of additives. This provided the proof-of-concept that the dual-nanostructured surface is amenable to large scale production through the use of roll-to-roll printing. A dual-nanostructured surface was produced by dropcasting the complex on silver nanowire surfaces to mimic the quality of surface achievable by an industrial production line. The dual-nanostructured surface produced a spatially consistent SERS response and an enhancement factor of 4.3x105 was tentatively assigned using the 1600 cm-1 peak of ATP.
适用于大规模生产的SERS双纳米结构方法Kory Brian Castro Old Dominion University, 2019主任:John Cooper博士使用由银纳米颗粒和银纳米线组成的双纳米结构表面制成了SERS装置。表征了每个纳米结构产生均匀表面的能力，并使用报告分子4氨基硫酚(ATP)和638 nm激发激光检测了所得表面的表面增强拉曼散射(SERS)响应。提出了一种制备长~20 μm、直径~100 nm、尺寸分布窄的银纳米线的合成方法。该方法采用简单的一锅合成方法，适于大规模生产。采用选择性沉淀法分离出高纯度~200宽高比银纳米线。这些金属丝是用迈耶棒涂在玻璃载玻片上的，可以很容易地产生均匀的表面。SERS反应被发现是高度可变的，取决于采样位置。利用ATP的1600 cm-1峰初步确定了2.2x105的增强因子。根据文献报道合成了银配合物μ-乙二胺银(I)。该配合物的水溶液被热分解，在玻片上产生sers活性的银表面。如果不使用添加剂，银配合物就不能产生均匀的表面涂层。在分解温度下浇铸该配合物，得到了约75 nm的球形纳米颗粒表面。发现该复合物表面具有sers活性，但其较差的加工特性阻碍了其在大规模器件生产中的适用性。采用银纳米线表面作为衬底，在不使用添加剂的情况下均匀地涂覆银络合物。这提供了概念证明，双纳米结构表面可以通过使用卷对卷印刷进行大规模生产。通过在银纳米线表面上浇铸复合材料，制备了双纳米结构表面，以模拟工业生产线所能达到的表面质量。双纳米结构表面产生了空间一致的SERS响应，并利用ATP的1600 cm-1峰初步确定了4.3x105的增强因子。
{"title":"A Dual-Nanostructured Approach to SERS Amenable to Large-Scale Production","authors":"K. B. Castro","doi":"10.25777/QKSW-9N49","DOIUrl":"https://doi.org/10.25777/QKSW-9N49","url":null,"abstract":"A DUAL-NANOSTRUCTURED APPROACH TO SERS AMENABLE TO LARGE-SCALE PRODUCTION Kory Brian Castro Old Dominion University, 2019 Director: Dr. John Cooper A SERS device was made using a dual-nanostructured surface comprised of silver nanoparticle and silver nanowires. The ability of each nanostructure to produce a uniform surface was characterized and the surface-enhanced Raman scattering (SERS) response of the resulting surfaces were examined using the reporter molecule 4aminothiolphenol (ATP) and a 638 nm excitation laser. A synthetic method was developed to produce silver nanowires with lengths of ~20 μm and diameters of ~100 nm with a narrow size distribution. The method utilized a simple, one-pot synthesis that is amenable to large-scale production. A selective precipitation method was used to the isolate the ~200 aspect ratio silver nanowires in a high purity. The wires were Mayer rod coated onto glass slides to produce uniform surfaces with ease. The SERS response was found to be highly variable depending on the sampled location. An enhancement factor of 2.2x105 was tentatively assigned using the 1600 cm-1 peak of ATP. The silver complex μ-oxolato-bis(ethylenediaminesilver(I)) was synthesized as reported in the literature. The aqueous solution of the complex was thermally decomposed to produce SERS-active silver surfaces on glass slides. The silver complex was unable to generate a uniform surface coating without the use of additives. By dropcasting the complex at the decomposition temperature, surfaces were generated exhibiting ~75 nm, spherical nanoparticles. The surface was found to be SERS-active, however the poor processing characteristics of the complex prevent its applicability to large-scale device production. Silver nanowire surfaces were used as substrates to Mayer rod coat the silver complex uniformly without the use of additives. This provided the proof-of-concept that the dual-nanostructured surface is amenable to large scale production through the use of roll-to-roll printing. A dual-nanostructured surface was produced by dropcasting the complex on silver nanowire surfaces to mimic the quality of surface achievable by an industrial production line. The dual-nanostructured surface produced a spatially consistent SERS response and an enhancement factor of 4.3x105 was tentatively assigned using the 1600 cm-1 peak of ATP.","PeriodicalId":22842,"journal":{"name":"Theory of Computing Systems \\/ Mathematical Systems Theory","volume":"364 1","pages":"7"},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85305093","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}
OFF AXIS COMPRESSIVE RESPONSE OF ICE TEMPLATED CERAMICS Rahul Kumar Jujjavarapu Old Dominion University, 2019 Co-Directors: Dr. Oleksandr Kravchenko Dr. Dipankar Ghosh The off-axis compressive behavior of ice-templated ceramic was analyzed using experimental results and micro-mechanical model simulation. Ice-templated ceramics is a versatile processing technique used to manufacture anisotropic ceramic foam by exploiting the anisotropic growth characteristics and lamellar morphology. The ice-templating process results in processing-structure-property relationships determined by the microstructure. The processed alumina samples which were later manufactured by water jet machine from the freeze casting were tested under quasi-static off-axis loading conditions and were used to determine the mechanical properties of the material. Digital image correlation (DIC) was used to measure the strain response of ice-templated ceramic under off-axis loading. DIC results revealed nonhomogenous strain distribution in the material during compression. Specifically, the origin of the localized strain concentration columnar regions, which are oriented in the ice-growth direction. Those regions were found to be the onset failure of in off-axis and 0-degree loading conditions. The experimental results reveal the strong influence of the loading direction on the compressive behavior of the ice-templated ceramic. A Representative Volume Element is developed to predict the behavior of off-axis loading. Micro-mechanical loading results in indicated that buckling of lamella walls were determined as the driving factor of failure. The results of the model compared favorably with the experimental results.
{"title":"Off Axis Compressive Response of Ice-Templated Ceramics","authors":"R. Jujjavarapu","doi":"10.25777/dekj-kp24","DOIUrl":"https://doi.org/10.25777/dekj-kp24","url":null,"abstract":"OFF AXIS COMPRESSIVE RESPONSE OF ICE TEMPLATED CERAMICS Rahul Kumar Jujjavarapu Old Dominion University, 2019 Co-Directors: Dr. Oleksandr Kravchenko Dr. Dipankar Ghosh The off-axis compressive behavior of ice-templated ceramic was analyzed using experimental results and micro-mechanical model simulation. Ice-templated ceramics is a versatile processing technique used to manufacture anisotropic ceramic foam by exploiting the anisotropic growth characteristics and lamellar morphology. The ice-templating process results in processing-structure-property relationships determined by the microstructure. The processed alumina samples which were later manufactured by water jet machine from the freeze casting were tested under quasi-static off-axis loading conditions and were used to determine the mechanical properties of the material. Digital image correlation (DIC) was used to measure the strain response of ice-templated ceramic under off-axis loading. DIC results revealed nonhomogenous strain distribution in the material during compression. Specifically, the origin of the localized strain concentration columnar regions, which are oriented in the ice-growth direction. Those regions were found to be the onset failure of in off-axis and 0-degree loading conditions. The experimental results reveal the strong influence of the loading direction on the compressive behavior of the ice-templated ceramic. A Representative Volume Element is developed to predict the behavior of off-axis loading. Micro-mechanical loading results in indicated that buckling of lamella walls were determined as the driving factor of failure. The results of the model compared favorably with the experimental results.","PeriodicalId":22842,"journal":{"name":"Theory of Computing Systems \\/ Mathematical Systems Theory","volume":"118 1","pages":"10"},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81673719","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":"Learning and Enhancing Important Fluctuations in Model Hamiltonian Systems","authors":"F. Cisneros","doi":"10.13016/3V4I-USDR","DOIUrl":"https://doi.org/10.13016/3V4I-USDR","url":null,"abstract":"","PeriodicalId":22842,"journal":{"name":"Theory of Computing Systems \\/ Mathematical Systems Theory","volume":"71 1","pages":"27"},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76231086","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The Effect of Morpholine and Polymer Network Structure on Electro-Optical Properties of Polymer Stabilized Cholesteric Liquid Crystals","authors":"D. Lippert","doi":"10.17077/etd.rdc4-82xo","DOIUrl":"https://doi.org/10.17077/etd.rdc4-82xo","url":null,"abstract":"","PeriodicalId":22842,"journal":{"name":"Theory of Computing Systems \\/ Mathematical Systems Theory","volume":"30 1","pages":"17"},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75482067","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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