This research is focused on image processing techniques for automatic detection of glaucoma in Retinal Optical Image Coherence Tomography. In the recent year, the interest on the automated glaucoma diagnosis techniques using the image processing techniques are exploding at an optimal rate which may help in the early diagnosis of the patients to recover from the permanent blindness. The manual diagnosis process for glaucoma detection within the medical community is tedious and time-consuming process that is susceptible to error. On the contrary image processing-based algorithms in constituent to deep learning can give better computation possibility in a trustworthy manner. The primary objective of the proposed research is to define proper image pre-processing techniques that aid in the process of the diagnosis. The aim is to aid in glaucoma detection by proposing image processing techniques to process the Optical Coherence Tomography images of the retina. The saturation removal technique is used for the intensity correction with histogram equalization of flattening the images. Resizing, filtering, and argumentation is also proposed in this research as possible image processing techniques. To show the generalized nature of the proposed approach, pre-processing techniques are employed on the OCT images which resulted in good results.
{"title":"Assorted Image Processing Techniques for Retinal OCT in Glaucoma Detection","authors":"N. Krishna, Dr Nagamani K","doi":"10.2139/ssrn.3734796","DOIUrl":"https://doi.org/10.2139/ssrn.3734796","url":null,"abstract":"This research is focused on image processing techniques for automatic detection of glaucoma in Retinal Optical Image Coherence Tomography. In the recent year, the interest on the automated glaucoma diagnosis techniques using the image processing techniques are exploding at an optimal rate which may help in the early diagnosis of the patients to recover from the permanent blindness. The manual diagnosis process for glaucoma detection within the medical community is tedious and time-consuming process that is susceptible to error. On the contrary image processing-based algorithms in constituent to deep learning can give better computation possibility in a trustworthy manner. The primary objective of the proposed research is to define proper image pre-processing techniques that aid in the process of the diagnosis. The aim is to aid in glaucoma detection by proposing image processing techniques to process the Optical Coherence Tomography images of the retina. The saturation removal technique is used for the intensity correction with histogram equalization of flattening the images. Resizing, filtering, and argumentation is also proposed in this research as possible image processing techniques. To show the generalized nature of the proposed approach, pre-processing techniques are employed on the OCT images which resulted in good results.","PeriodicalId":18268,"journal":{"name":"Materials Engineering eJournal","volume":"7 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90638280","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}
J. Österreicher, C. Simson, Alexander Großalber, Simon Frank, S. Gneiger
Abstract The quantification of lithium in electron microscopes by energy-dispersive X-ray spectroscopy (EDS) is highly challenging due to the low energy of the characteristic X-rays. Only special windowless detectors can detect Li, yet the sensitivity is suboptimal (i.e., ~20 wt. %). We introduce the use of quantitative backscattered electron microscopy in combination with measurements using a standard EDS sensor to achieve spatially resolved quantification of Li. The method is demonstrated using two Mg-Li alloys with 4 and 20 wt. % Li and good accuracy with a deviation of only ~1.2 wt. % and ~2.5 wt. %, respectively, is achieved.
{"title":"Spatial Lithium Quantification by Backscattered Electron Microscopy Coupled with Energy-Dispersive X-Ray Spectroscopy","authors":"J. Österreicher, C. Simson, Alexander Großalber, Simon Frank, S. Gneiger","doi":"10.2139/ssrn.3734077","DOIUrl":"https://doi.org/10.2139/ssrn.3734077","url":null,"abstract":"Abstract The quantification of lithium in electron microscopes by energy-dispersive X-ray spectroscopy (EDS) is highly challenging due to the low energy of the characteristic X-rays. Only special windowless detectors can detect Li, yet the sensitivity is suboptimal (i.e., ~20 wt. %). We introduce the use of quantitative backscattered electron microscopy in combination with measurements using a standard EDS sensor to achieve spatially resolved quantification of Li. The method is demonstrated using two Mg-Li alloys with 4 and 20 wt. % Li and good accuracy with a deviation of only ~1.2 wt. % and ~2.5 wt. %, respectively, is achieved.","PeriodicalId":18268,"journal":{"name":"Materials Engineering eJournal","volume":"27 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89660716","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}
Jiantao Fan, Yanle Sun, L. Fu, Xin-bo Ji, J. Peng, Pengfei Yu, Feng Xu, Wei Wang, G. Li, M. Wen, A. Shan
The development of high-performance alloys with excellent strength-ductility synergy is a long-lasting research theme for materials science community, which also holds for the newly emerged complex-concentrated alloys (CCAs). Here, a multi-heterogeneous microstructure: featuring a multiscale grain distribution involving recrystallized ultrafine and fine grains mixed with unrecrystallized coarse grains, and high-content L1 2 nanoprecipitates, was intentionally introduced into a Co-free CCA through appropriate thermomechanical processing strategy. As such, the hetero-deformation induced (HDI) hardening and precipitation strengthening were co-effectively used, resulting in a high yield strength of 1.2 GPa, and an ultimate tensile strength of 1.4 GPa with exceptional uniform elongation of ~17.6%. The strength-ductility synergy of the multi-hetero microstructure was much enhanced over its precipitate-strengthened counterparts without heterogenous grains. We demonstrated that the high yield strength is mainly due to both the precipitate strengthening from nanoprecipitates and HDI strengthening from heterogeneous grains distribution. Benefiting from the structurally incompatible deformation accompanying with copious geometrically necessary dislocations near the hetero-interfaces, such multi-hetero microstructure revealed a distinctive up-turn strain hardening behavior due to the HDI hardening upon straining, and thus delayed the onset of plastic instability. Particularly, the unique lamellar-like distribution between recrystallized fine and ultrafine grains with high density of interfaces could effectively induce massive HDI hardening during deformation. The processing strategy described here is relatively simple and desirable for large scale process in modern industry at an economic cost.
{"title":"Enhancing Strength-Ductility Synergy of a Co-Free Complex-Concentrated Alloy Via Tailored Multi-Heterogeneous Microstructure","authors":"Jiantao Fan, Yanle Sun, L. Fu, Xin-bo Ji, J. Peng, Pengfei Yu, Feng Xu, Wei Wang, G. Li, M. Wen, A. Shan","doi":"10.2139/ssrn.3734071","DOIUrl":"https://doi.org/10.2139/ssrn.3734071","url":null,"abstract":"The development of high-performance alloys with excellent strength-ductility synergy is a long-lasting research theme for materials science community, which also holds for the newly emerged complex-concentrated alloys (CCAs). Here, a multi-heterogeneous microstructure: featuring a multiscale grain distribution involving recrystallized ultrafine and fine grains mixed with unrecrystallized coarse grains, and high-content L1 2 nanoprecipitates, was intentionally introduced into a Co-free CCA through appropriate thermomechanical processing strategy. As such, the hetero-deformation induced (HDI) hardening and precipitation strengthening were co-effectively used, resulting in a high yield strength of 1.2 GPa, and an ultimate tensile strength of 1.4 GPa with exceptional uniform elongation of ~17.6%. The strength-ductility synergy of the multi-hetero microstructure was much enhanced over its precipitate-strengthened counterparts without heterogenous grains. We demonstrated that the high yield strength is mainly due to both the precipitate strengthening from nanoprecipitates and HDI strengthening from heterogeneous grains distribution. Benefiting from the structurally incompatible deformation accompanying with copious geometrically necessary dislocations near the hetero-interfaces, such multi-hetero microstructure revealed a distinctive up-turn strain hardening behavior due to the HDI hardening upon straining, and thus delayed the onset of plastic instability. Particularly, the unique lamellar-like distribution between recrystallized fine and ultrafine grains with high density of interfaces could effectively induce massive HDI hardening during deformation. The processing strategy described here is relatively simple and desirable for large scale process in modern industry at an economic cost.","PeriodicalId":18268,"journal":{"name":"Materials Engineering eJournal","volume":"16 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87997446","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}
Masayoshi Yoshimatsu, Hiroe Ohnishi, Chengzhu Zhao, Yasuyuki Hayashi, Fumihiko Kuwata, S. Kaba, Hideaki Okuyama, Yoshitaka Kawai, Nao Hiwatashi, Yo Kishimoto, T. Sakamoto, M. Ikeya, K. Omori
The laryngotracheal cartilage is a cardinal framework for the maintenance of the airway for breathing, which occasionally requires reconstruction. Because hyaline cartilage has a poor intrinsic regenerative ability, various regenerative approaches have been attempted to regenerate laryngotracheal cartilage. The use of autologous mesenchymal stem cells (MSCs) for cartilage regeneration has been widely investigated. However, long-term culture may limit proliferative capacity. Human-induced pluripotent stem cell-derived MSCs (iMSCs) can circumvent this problem due to their unlimited proliferative capacity. This study aimed to investigate the efficacy of iMSCs in the regeneration of thyroid cartilage in immunodeficient rats. Herein, we induced iMSCs through neural crest cell intermediates. For the relevance to prospective future clinical application, induction was conducted under xeno-free/serum-free conditions. Then, clumps fabricated from an iMSC/extracellular matrix complex (C-iMSC) were transplanted into thyroid cartilage defects in immunodeficient rats. Histological examinations revealed cartilage-like regenerated tissue and human nuclear antigen (HNA)-positive surviving transplanted cells in the regenerated lesion. HNA-positive cells co-expressed SOX9, and type II collagen was identified around HNA-positive cells. These results indicated that the transplanted C-iMSCs promoted thyroid cartilage regeneration and some of the iMSCs differentiated into chondrogenic lineage cells. Induced MSCs may be a promising candidate cell therapy for human laryngotracheal reconstruction.
{"title":"In Vivo Regeneration of Rat Laryngeal Cartilage with Mesenchymal Stem Cells Derived from Human Induced Pluripotent Stem Cells Via Neural Crest Cells","authors":"Masayoshi Yoshimatsu, Hiroe Ohnishi, Chengzhu Zhao, Yasuyuki Hayashi, Fumihiko Kuwata, S. Kaba, Hideaki Okuyama, Yoshitaka Kawai, Nao Hiwatashi, Yo Kishimoto, T. Sakamoto, M. Ikeya, K. Omori","doi":"10.2139/ssrn.3733569","DOIUrl":"https://doi.org/10.2139/ssrn.3733569","url":null,"abstract":"The laryngotracheal cartilage is a cardinal framework for the maintenance of the airway for breathing, which occasionally requires reconstruction. Because hyaline cartilage has a poor intrinsic regenerative ability, various regenerative approaches have been attempted to regenerate laryngotracheal cartilage. The use of autologous mesenchymal stem cells (MSCs) for cartilage regeneration has been widely investigated. However, long-term culture may limit proliferative capacity. Human-induced pluripotent stem cell-derived MSCs (iMSCs) can circumvent this problem due to their unlimited proliferative capacity. This study aimed to investigate the efficacy of iMSCs in the regeneration of thyroid cartilage in immunodeficient rats. Herein, we induced iMSCs through neural crest cell intermediates. For the relevance to prospective future clinical application, induction was conducted under xeno-free/serum-free conditions. Then, clumps fabricated from an iMSC/extracellular matrix complex (C-iMSC) were transplanted into thyroid cartilage defects in immunodeficient rats. Histological examinations revealed cartilage-like regenerated tissue and human nuclear antigen (HNA)-positive surviving transplanted cells in the regenerated lesion. HNA-positive cells co-expressed SOX9, and type II collagen was identified around HNA-positive cells. These results indicated that the transplanted C-iMSCs promoted thyroid cartilage regeneration and some of the iMSCs differentiated into chondrogenic lineage cells. Induced MSCs may be a promising candidate cell therapy for human laryngotracheal reconstruction.","PeriodicalId":18268,"journal":{"name":"Materials Engineering eJournal","volume":"50 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84449598","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. Kaviani, Elham Tavakoli, J. Dai, Xiaoxing Zeng, S. Nejati
Thin films of polymer from 3,4-ethylenedithiathiophene (EDTT) were synthesized using oxidative chemical vapor deposition (oCVD). The synthesized materials were electrochemically active and revealed bifunctional electrocatalytic activities, catalyzing oxygen reduction and evolution reactions, with the onset potentials of 0.87 V and 1.72 V vs reversible hydrogen electrode (RHE), respectively. Density functional theory (DFT) calculations revealed that the carbon atoms, adjacent to the heteroatom in the thiophene ring, are the catalytic sites. We applied a thin-film of PEDTT onto a gas diffusion layer fabric to create an air-cathode for integration into the architecture of rechargeable zinc-air batteries.
{"title":"An Organic Polymer with a Bifunctional Electrocatalytic Activity in Oxygen Reactions","authors":"S. Kaviani, Elham Tavakoli, J. Dai, Xiaoxing Zeng, S. Nejati","doi":"10.2139/ssrn.3733159","DOIUrl":"https://doi.org/10.2139/ssrn.3733159","url":null,"abstract":"Thin films of polymer from 3,4-ethylenedithiathiophene (EDTT) were synthesized using oxidative chemical vapor deposition (oCVD). The synthesized materials were electrochemically active and revealed bifunctional electrocatalytic activities, catalyzing oxygen reduction and evolution reactions, with the onset potentials of 0.87 V and 1.72 V vs reversible hydrogen electrode (RHE), respectively. Density functional theory (DFT) calculations revealed that the carbon atoms, adjacent to the heteroatom in the thiophene ring, are the catalytic sites. We applied a thin-film of PEDTT onto a gas diffusion layer fabric to create an air-cathode for integration into the architecture of rechargeable zinc-air batteries.","PeriodicalId":18268,"journal":{"name":"Materials Engineering eJournal","volume":"86 18 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84013006","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 : 2020-11-11DOI: 10.15587/1729-4061.2020.217009
E. Fedorenko, G. Lisachuk, M. Prytkina, R. Kryvobok, A. Zakharov
Designing new materials with unique properties requires scientifically substantiated approaches to problem-solving. Applying a physical-chemical analysis of oxide systems to devise the formulation for a material makes it possible to determine the conditions of phase formation and assess the manufacturability of compositions. Given the enormous number of experiments required to build the state diagrams of multi-component oxide systems, the physical-chemical modeling is the most appropriate method to study their structure. This paper substantiates the selection of the basic oxide system ZnO‒SrO‒Al 2 O 3 ‒SiO 2 to design radio-transparent ceramics and reports the results of studying its subsolidus structure using modern data on splitting the system into elementary volumes. The main geometric-topological characteristics of the system's internal tetrahedra have been defined and analyzed; the minimum temperatures for melt occurrence have been calculated, as well as the eutectic compositions. To design radio-transparent ceramics with a predefined level of dielectric characteristics (e<10, tgd<10 -2 ), a region of the formulations has been selected within the tetrahedron SiO 2 –ZnAl 2 O 4 –ZnSiO 4 –SrAl 2 Si 2 O 8 concentrations, which ensure the synthesis of the target phases of willemite and strontium anorthite. By using the new data, heat-resistant polyphase ceramics have been obtained, whose dielectric characteristics (e=5.98‒8.96; tgd=0.004‒0.008) meet the requirements for radio transparent materials. The optimal ratio of phases (ZnSiO 4 :SrAl 2 Si 2 O 8= 1:1) has been established, which makes it possible to reduce dielectric permeability (e=5.98) and minimize dielectric losses (tgd=0.004). Scanning electron microscopy and X-ray analysis were used to determine the structural and phase features of the new ceramic materials
{"title":"Subsolidus Structure of the ZnO–SrO–Al 2O 3–SiO 2 System as a Base for Designing Radiotransparent Ceramics","authors":"E. Fedorenko, G. Lisachuk, M. Prytkina, R. Kryvobok, A. Zakharov","doi":"10.15587/1729-4061.2020.217009","DOIUrl":"https://doi.org/10.15587/1729-4061.2020.217009","url":null,"abstract":"Designing new materials with unique properties requires scientifically substantiated approaches to problem-solving. Applying a physical-chemical analysis of oxide systems to devise the formulation for a material makes it possible to determine the conditions of phase formation and assess the manufacturability of compositions. Given the enormous number of experiments required to build the state diagrams of multi-component oxide systems, the physical-chemical modeling is the most appropriate method to study their structure. This paper substantiates the selection of the basic oxide system ZnO‒SrO‒Al 2 O 3 ‒SiO 2 to design radio-transparent ceramics and reports the results of studying its subsolidus structure using modern data on splitting the system into elementary volumes. The main geometric-topological characteristics of the system's internal tetrahedra have been defined and analyzed; the minimum temperatures for melt occurrence have been calculated, as well as the eutectic compositions. To design radio-transparent ceramics with a predefined level of dielectric characteristics (e<10, tgd<10 -2 ), a region of the formulations has been selected within the tetrahedron SiO 2 –ZnAl 2 O 4 –ZnSiO 4 –SrAl 2 Si 2 O 8 concentrations, which ensure the synthesis of the target phases of willemite and strontium anorthite. By using the new data, heat-resistant polyphase ceramics have been obtained, whose dielectric characteristics (e=5.98‒8.96; tgd=0.004‒0.008) meet the requirements for radio transparent materials. The optimal ratio of phases (ZnSiO 4 :SrAl 2 Si 2 O 8= 1:1) has been established, which makes it possible to reduce dielectric permeability (e=5.98) and minimize dielectric losses (tgd=0.004). Scanning electron microscopy and X-ray analysis were used to determine the structural and phase features of the new ceramic materials","PeriodicalId":18268,"journal":{"name":"Materials Engineering eJournal","volume":"69 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84994592","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 : 2020-10-31DOI: 10.15587/1729-4061.2020.215145
E. Vereschago, V. Kostiuchenko, S. Novogretskyi
A simulation model of a converter with soft switching of transistors has been created. New calculation methods and means of measuring the equivalent frequency characteristics of converting devices with negative feedback to the problems of stability analysis have been applied. A comparative analysis of the calculated frequency characteristics of the converter in the normal operation mode with the characteristics of its linear model is presented. The features of calculating the equivalent frequency characteristics of the loop amplification of key devices are considered. It is noted that it is the equivalent frequency characteristics of the loop amplification that describe the relationship of frequency properties with the dynamics of voltage converters with pulse-width modulation and make it possible to reliably determine the real stability margins, predict the generation modes and open up the possibility of obtaining maximum negative feedback in a given frequency band of key devices. The non-minimal phase properties of the converter significantly complicate the achievement of high-quality stabilization of the output current (stabilization coefficient) of pulse stabilizers using only the deflection control principle. A successful solution to the problem is provided by the use of the principle of combined control. Compensation of the disturbance effect (changes in the supply voltage) gives a much better result than countering it through the feedback loop. It is quite realistic to exclude the influence of the input voltage u ( t ) on the output current i 2 in a static mode ( u =const) and in the absence of a negative feedback loop, which provides for u =const in a steady state, and to provide better dynamic properties of the converter. The influence of the nonlinear properties of pulse width modulation on stability is manifested in the considered characteristics in the form of an additional phase shift and resonant bursts in the vicinity of the clock frequency subharmonics. Additional feedbacks introduced into the control loop make it possible to solve synthesis problems using the most simple technical means
{"title":"Analysis of Dynamic Characteristics of the Inverter Operating on a Complex Load","authors":"E. Vereschago, V. Kostiuchenko, S. Novogretskyi","doi":"10.15587/1729-4061.2020.215145","DOIUrl":"https://doi.org/10.15587/1729-4061.2020.215145","url":null,"abstract":"A simulation model of a converter with soft switching of transistors has been created. New calculation methods and means of measuring the equivalent frequency characteristics of converting devices with negative feedback to the problems of stability analysis have been applied. A comparative analysis of the calculated frequency characteristics of the converter in the normal operation mode with the characteristics of its linear model is presented. The features of calculating the equivalent frequency characteristics of the loop amplification of key devices are considered. It is noted that it is the equivalent frequency characteristics of the loop amplification that describe the relationship of frequency properties with the dynamics of voltage converters with pulse-width modulation and make it possible to reliably determine the real stability margins, predict the generation modes and open up the possibility of obtaining maximum negative feedback in a given frequency band of key devices. The non-minimal phase properties of the converter significantly complicate the achievement of high-quality stabilization of the output current (stabilization coefficient) of pulse stabilizers using only the deflection control principle. A successful solution to the problem is provided by the use of the principle of combined control. Compensation of the disturbance effect (changes in the supply voltage) gives a much better result than countering it through the feedback loop. It is quite realistic to exclude the influence of the input voltage u ( t ) on the output current i 2 in a static mode ( u =const) and in the absence of a negative feedback loop, which provides for u =const in a steady state, and to provide better dynamic properties of the converter. The influence of the nonlinear properties of pulse width modulation on stability is manifested in the considered characteristics in the form of an additional phase shift and resonant bursts in the vicinity of the clock frequency subharmonics. Additional feedbacks introduced into the control loop make it possible to solve synthesis problems using the most simple technical means","PeriodicalId":18268,"journal":{"name":"Materials Engineering eJournal","volume":"43 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88044136","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 : 2020-10-31DOI: 10.15587/1729-4061.2020.210462
R. Subagyo, H. Isworo
The rapid population growth has an impact on the increasing need for drinking water. In swamp areas, the need for drinking water cannot be met immediately because it still contains organic compounds that make the water unfit for consumption. Peat water contains dissolved organic compounds that cause the water to turn brown and have an acidic character, so it needs special processing before it is ready for consumption. For peat water to be used by the community for drinking water, it is necessary to find an easy and cheap way to treat peat water. The use of a filtration device is one of the solutions that must be done in peat water treatment. The purpose of this study was to determine the effect of flow patterns, speed, and pressure on the filtration process with variations in the type of membrane and filtration arrangement. This research method was carried out by simulation using ANSYS 14.5 series. The simulation process begins with designing a filtration device with the following types: two-filter, three-filter, and four-filter. Then the simulation was performed by entering the value of the peat water properties into the regulatory equation.
The results of this study indicate that the collaboration of two membranes with different holes in type-2 and 3 filters produces a good filtration rate. However, in type-4 filters, the use of a similar membrane is highly recommended. This filtration rate is influenced by the presence of a cross-flow reversal (CFR) region that appears, when using different filtration membranes at low pressure it doesn't matter. However, in other cases of systems operating at high pressure, CFR that appears tends to decrease the filtration rate, this is because CFR inhibits the flow rate in the filtration process.
{"title":"Membrane Filtration Simulation Study With Variation in the Number of Filters on Peat Water Media","authors":"R. Subagyo, H. Isworo","doi":"10.15587/1729-4061.2020.210462","DOIUrl":"https://doi.org/10.15587/1729-4061.2020.210462","url":null,"abstract":"The rapid population growth has an impact on the increasing need for drinking water. In swamp areas, the need for drinking water cannot be met immediately because it still contains organic compounds that make the water unfit for consumption. Peat water contains dissolved organic compounds that cause the water to turn brown and have an acidic character, so it needs special processing before it is ready for consumption. For peat water to be used by the community for drinking water, it is necessary to find an easy and cheap way to treat peat water. The use of a filtration device is one of the solutions that must be done in peat water treatment. The purpose of this study was to determine the effect of flow patterns, speed, and pressure on the filtration process with variations in the type of membrane and filtration arrangement. This research method was carried out by simulation using ANSYS 14.5 series. The simulation process begins with designing a filtration device with the following types: two-filter, three-filter, and four-filter. Then the simulation was performed by entering the value of the peat water properties into the regulatory equation.<br><br>The results of this study indicate that the collaboration of two membranes with different holes in type-2 and 3 filters produces a good filtration rate. However, in type-4 filters, the use of a similar membrane is highly recommended. This filtration rate is influenced by the presence of a cross-flow reversal (CFR) region that appears, when using different filtration membranes at low pressure it doesn't matter. However, in other cases of systems operating at high pressure, CFR that appears tends to decrease the filtration rate, this is because CFR inhibits the flow rate in the filtration process.","PeriodicalId":18268,"journal":{"name":"Materials Engineering eJournal","volume":"68 1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82984768","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 : 2020-10-30DOI: 10.15587/1729-4061.2020.214856
O. Solovey, A. Ben, S. Dudchenko, P. Nosov
The aim of the work is to develop a method for optimal control of handling operations with heavy lift cargo on sea vessels. Based on the review of scientific research in the field of loading heavy lift cargo, priority directions for improving the automated control systems for cargo handling operations on ships have been determined. Within a scientific hypothesis, it was proposed to synchronize solutions to the problem of ship propulsion control and automated control of heavy lift onboard cranes in order to improve the accuracy of loading processes. The paper analyzes the dynamic model of the “vessel-crane-cargo” system and the criteria of optimality in the problem of ship regulation-stabilization under minimization of loading time. An inverse loading algorithm has been developed, based on the principles of the loading control optimization with limiting the choice of motion by linear displacements and turns of the vessel. When executing the inverse algorithm, restrictions associated with the minimization of heeling moments in the “vessel-crane-cargo” system and restrictions associated with the maximum and minimum boom outreach are applied. The study determined the technical feasibility of achieving invariance in the cargo stabilization system with the inverse loading algorithm on heavy lift vessels. On the basis of the proposed method, simulation modeling of the ship loading process was carried out on simulators at the Kherson State Maritime Academy. The simulation modeling has shown that the use of the inverse algorithm will reduce the time of cargo operations by 50–70 percent and, as a result, reduce the risk of emergencies when loading the ship. It was also determined that the use of the inverse algorithm is appropriate for cargo of more than 100 tons
{"title":"Development of Control Model for Loading Operations on Heavy Lift Vessels Based on Inverse Algorithm","authors":"O. Solovey, A. Ben, S. Dudchenko, P. Nosov","doi":"10.15587/1729-4061.2020.214856","DOIUrl":"https://doi.org/10.15587/1729-4061.2020.214856","url":null,"abstract":"The aim of the work is to develop a method for optimal control of handling operations with heavy lift cargo on sea vessels. Based on the review of scientific research in the field of loading heavy lift cargo, priority directions for improving the automated control systems for cargo handling operations on ships have been determined. Within a scientific hypothesis, it was proposed to synchronize solutions to the problem of ship propulsion control and automated control of heavy lift onboard cranes in order to improve the accuracy of loading processes. The paper analyzes the dynamic model of the “vessel-crane-cargo” system and the criteria of optimality in the problem of ship regulation-stabilization under minimization of loading time. An inverse loading algorithm has been developed, based on the principles of the loading control optimization with limiting the choice of motion by linear displacements and turns of the vessel. When executing the inverse algorithm, restrictions associated with the minimization of heeling moments in the “vessel-crane-cargo” system and restrictions associated with the maximum and minimum boom outreach are applied. The study determined the technical feasibility of achieving invariance in the cargo stabilization system with the inverse loading algorithm on heavy lift vessels. On the basis of the proposed method, simulation modeling of the ship loading process was carried out on simulators at the Kherson State Maritime Academy. The simulation modeling has shown that the use of the inverse algorithm will reduce the time of cargo operations by 50–70 percent and, as a result, reduce the risk of emergencies when loading the ship. It was also determined that the use of the inverse algorithm is appropriate for cargo of more than 100 tons","PeriodicalId":18268,"journal":{"name":"Materials Engineering eJournal","volume":"33 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77306710","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 : 2020-10-30DOI: 10.5121/sipij.2020.11503
C. Kwan, Jude Larkin
In modern digital cameras, the Bayer color filter array (CFA) has been widely used. It is also widely known as CFA 1.0. However, Bayer pattern is inferior to the red-green-blue-white (RGBW) pattern, which is also known as CFA 2.0, in low lighting conditions in which Poisson noise is present. It is well known that demosaicing algorithms cannot effectively deal with Poisson noise and additional denoising is needed in order to improve the image quality. In this paper, we propose to evaluate various conventional and deep learning based denoising algorithms for CFA 2.0 in low lighting conditions. We will also investigate the impact of the location of denoising, which refers to whether the denoising is done before or after a critical step of demosaicing. Extensive experiments show that some denoising algorithms can indeed improve the image quality in low lighting conditions. We also noticed that the location of denoising plays an important role in the overall demosaicing performance.
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