Fatin Farisha Alia Azmi, B. Sahraoui, Saifful K Muzakir
A solar cell is a device that absorbs light energy to generate electrical energy. A typical example of a solar cell is the quantum dot solar cell (QDSC), which consists of three main components: (i) fluorophore: the component that absorbs light and generates excited state electrons and holes, (ii) photoelectrode: the component that transports the excited state electron and prevents recombination of excited state electrons and holes, and (iii) electrolyte: the component that replenishes the vacancy left by the excited electron in the hole. Despite the increasing number of research in the QDSC field, to date, a device with significant photovoltaic efficiency has not been developed. In this study, the mechanism of electron transport in a zinc oxide (ZnO) photoelectrode was investigated. Two ZnO layers were fabricated using thermal evaporation method at different vacuum pressures (5 × 10 and 5 × 10 Torr). Two solar cells were fabricated using ZnO as photoelectrode, lead sulphide as fluorophore, and a mixture of carboxymethyl cellulose and polyvinyl alcohol as electrolyte. The cell which utilized the ZnO fabricated under 5 × 10 Torr showed the highest efficiency ( = 0.98%), with fill factor = 22.07%, short circuit current = 2.85 mA/m, and open circuit voltage = 80.719 mV.
{"title":"Study of ZnO Nanospheres Fabricated via Thermal Evaporation for Solar Cell Application","authors":"Fatin Farisha Alia Azmi, B. Sahraoui, Saifful K Muzakir","doi":"10.7454/MST.V23I1.3644","DOIUrl":"https://doi.org/10.7454/MST.V23I1.3644","url":null,"abstract":"A solar cell is a device that absorbs light energy to generate electrical energy. A typical example of a solar cell is the quantum dot solar cell (QDSC), which consists of three main components: (i) fluorophore: the component that absorbs light and generates excited state electrons and holes, (ii) photoelectrode: the component that transports the excited state electron and prevents recombination of excited state electrons and holes, and (iii) electrolyte: the component that replenishes the vacancy left by the excited electron in the hole. Despite the increasing number of research in the QDSC field, to date, a device with significant photovoltaic efficiency has not been developed. In this study, the mechanism of electron transport in a zinc oxide (ZnO) photoelectrode was investigated. Two ZnO layers were fabricated using thermal evaporation method at different vacuum pressures (5 × 10 and 5 × 10 Torr). Two solar cells were fabricated using ZnO as photoelectrode, lead sulphide as fluorophore, and a mixture of carboxymethyl cellulose and polyvinyl alcohol as electrolyte. The cell which utilized the ZnO fabricated under 5 × 10 Torr showed the highest efficiency ( = 0.98%), with fill factor = 22.07%, short circuit current = 2.85 mA/m, and open circuit voltage = 80.719 mV.","PeriodicalId":42980,"journal":{"name":"Makara Journal of Technology","volume":" ","pages":""},"PeriodicalIF":0.2,"publicationDate":"2019-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45471196","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}
Mahallah Halimatus Saadiah, Dishen Zhang, Y. Nagao, A. S. Samsudin
This study investigated the electrical conduction and structural behavior of blended polymer electrolyte (BPE)-based carboxymethyl cellulose (CMC) and polyvinyl alcohol (PVA) in the development of solid-state electrochemical devices. Based on impedance spectroscopy and correlating Fourier transform infrared (FTIR) with thermogravimetric analysis, a framework was proposed to explain the structural enhancement of the BPE system. As revealed by FTIR, the optimum conductivity of CMC/PVA BPEs was 9.21× 10− 6 Scm− 1 for 80: 20 composition attributed to the intermolecular attraction between the polymers. Thermal stability of the CMC/PVA was influenced by the formation of a hydrogen bond between the hydroxyl (-OH), carboxylate (-COO-), and ether linkage (-COC-) functional groups. The finding provides insights into blended polymer electrolyte-based CMC/PVA, which is beneficial in designing safe, thin, and lightweight energy storage devices.
{"title":"Molecularly Conductive Behavior of Blended Polymer Electrolyte-based CMC/PVA","authors":"Mahallah Halimatus Saadiah, Dishen Zhang, Y. Nagao, A. S. Samsudin","doi":"10.7454/MST.V23I1.3639","DOIUrl":"https://doi.org/10.7454/MST.V23I1.3639","url":null,"abstract":"This study investigated the electrical conduction and structural behavior of blended polymer electrolyte (BPE)-based carboxymethyl cellulose (CMC) and polyvinyl alcohol (PVA) in the development of solid-state electrochemical devices. Based on impedance spectroscopy and correlating Fourier transform infrared (FTIR) with thermogravimetric analysis, a framework was proposed to explain the structural enhancement of the BPE system. As revealed by FTIR, the optimum conductivity of CMC/PVA BPEs was 9.21× 10− 6 Scm− 1 for 80: 20 composition attributed to the intermolecular attraction between the polymers. Thermal stability of the CMC/PVA was influenced by the formation of a hydrogen bond between the hydroxyl (-OH), carboxylate (-COO-), and ether linkage (-COC-) functional groups. The finding provides insights into blended polymer electrolyte-based CMC/PVA, which is beneficial in designing safe, thin, and lightweight energy storage devices.","PeriodicalId":42980,"journal":{"name":"Makara Journal of Technology","volume":" ","pages":""},"PeriodicalIF":0.2,"publicationDate":"2019-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44085361","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}
Nurul Laili Arifin, E. Savitri, A. Indah, Fesa Putra, S. Sumarno
The sonication method randomly breaks polymer chains to produce a varied distribution of products. A scheme with multistage sonication steps is proposed to identify oligomers and low molecular weight chitosan based on changes to the degraded product. For each sonication level, 1% (w/v) chitosan in 1% (v/v) aqueous acetic acid was sonicated for 120 min at 60 °C. The products of the sonication treatment were deprotonized by adding an alkali solution, freeze dried and insoluble product re-sonicated until a low molecular weight was produced. Low molecular weight chitosan/insoluble products were characterized with Fourier-transform infrared spectra (FT-IR) and X-ray diffraction (XRD) to determine the effect of multistage sonication on degree of deacetylation (DD) and degree of crystallinity. The viscosity of the average molecular weight of insoluble chitosan was estimated by a viscometric method, while the degree of polymerization (DP) of the chitosan oligomers (COS) were determined by end group analysis. The results showed that the molecular weight of insoluble chitosan decreased and reached a limiting value, (Mlim). The percent yield of oligoglucosamine of the soluble products increased with the number of the sonication stages. The degree of crystallinity of insoluble chitosan increased from 19% to 34.14% while the DD decreased from 82% to 78.1%.
{"title":"Multistage Sonication Effect on the Composition and Properties of Degraded Chitosan Product","authors":"Nurul Laili Arifin, E. Savitri, A. Indah, Fesa Putra, S. Sumarno","doi":"10.7454/MST.V23I1.3585","DOIUrl":"https://doi.org/10.7454/MST.V23I1.3585","url":null,"abstract":"The sonication method randomly breaks polymer chains to produce a varied distribution of products. A scheme with multistage sonication steps is proposed to identify oligomers and low molecular weight chitosan based on changes to the degraded product. For each sonication level, 1% (w/v) chitosan in 1% (v/v) aqueous acetic acid was sonicated for 120 min at 60 °C. The products of the sonication treatment were deprotonized by adding an alkali solution, freeze dried and insoluble product re-sonicated until a low molecular weight was produced. Low molecular weight chitosan/insoluble products were characterized with Fourier-transform infrared spectra (FT-IR) and X-ray diffraction (XRD) to determine the effect of multistage sonication on degree of deacetylation (DD) and degree of crystallinity. The viscosity of the average molecular weight of insoluble chitosan was estimated by a viscometric method, while the degree of polymerization (DP) of the chitosan oligomers (COS) were determined by end group analysis. The results showed that the molecular weight of insoluble chitosan decreased and reached a limiting value, (Mlim). The percent yield of oligoglucosamine of the soluble products increased with the number of the sonication stages. The degree of crystallinity of insoluble chitosan increased from 19% to 34.14% while the DD decreased from 82% to 78.1%.","PeriodicalId":42980,"journal":{"name":"Makara Journal of Technology","volume":" ","pages":""},"PeriodicalIF":0.2,"publicationDate":"2019-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44363357","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}
This paper discusses data fusion methods to combine the data from a rotary encoder and ultrasonic sensor. Both sensors are used in a micro-flow calibration system developed by the Research Center of Metrology LIPI. The methods studied are hierarchical data fusion and Kalman filtering. Three types of Kalman filters (KFs) are compared: the conventional Kalman filter and two adaptive Kalman filters. Moreover, a method to combine the uncertainty results from KF in hierarchical data fusion is proposed. The aim of this study is to find appropriate methods of data fusion that can be implemented in microflow calibration systems. Data from two experiment setups are used to compare the methods. The result indicates that one of the methods (with little adjustment) is more appropriate than the other.
{"title":"Data Fusion Method Based on Adaptive Kalman Filtering","authors":"B. Sirenden","doi":"10.7454/MST.V23I1.3432","DOIUrl":"https://doi.org/10.7454/MST.V23I1.3432","url":null,"abstract":"This paper discusses data fusion methods to combine the data from a rotary encoder and ultrasonic sensor. Both sensors are used in a micro-flow calibration system developed by the Research Center of Metrology LIPI. The methods studied are hierarchical data fusion and Kalman filtering. Three types of Kalman filters (KFs) are compared: the conventional Kalman filter and two adaptive Kalman filters. Moreover, a method to combine the uncertainty results from KF in hierarchical data fusion is proposed. The aim of this study is to find appropriate methods of data fusion that can be implemented in microflow calibration systems. Data from two experiment setups are used to compare the methods. The result indicates that one of the methods (with little adjustment) is more appropriate than the other.","PeriodicalId":42980,"journal":{"name":"Makara Journal of Technology","volume":" ","pages":""},"PeriodicalIF":0.2,"publicationDate":"2019-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46122368","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In the present study, a novel solid biopolymer electrolytes (SBE) system has been introduced by doping citric acid into alginate polymer. The sample of alginate-citric acid SBE system was prepared via solution casting technique. By using Electrical Impedance Spectroscopy (EIS), the electrolytes of alginate-citric acid has been analyzed from 5 Hz to 1 MHz achieved highest conductivity value at 20 wt.% of 5.49 x 10-7 S cm-1. The temperature dependence of various composition citric acid was found to obey the Arrhenius rules with R2~1 where all SBE system is thermally activated when increasing temperature. The dielectric studies of the alginate-citric acid SBE system showed a non-debye behavior based on data measured using complex permittivity (e*) and complex electrical modulus (M*) at selected temperature where there are no single relation was found in new biopolymer electrolytes system.
{"title":"Electrical Properties of A Novel Solid Biopolymer Electrolyte based on Algi-nate Incorporated with Citric Acid","authors":"A. F. Fuzlin, N. Ismail, Y. Nagao, A. S. Samsudin","doi":"10.7454/MST.V23I1.3643","DOIUrl":"https://doi.org/10.7454/MST.V23I1.3643","url":null,"abstract":"In the present study, a novel solid biopolymer electrolytes (SBE) system has been introduced by doping citric acid into alginate polymer. The sample of alginate-citric acid SBE system was prepared via solution casting technique. By using Electrical Impedance Spectroscopy (EIS), the electrolytes of alginate-citric acid has been analyzed from 5 Hz to 1 MHz achieved highest conductivity value at 20 wt.% of 5.49 x 10-7 S cm-1. The temperature dependence of various composition citric acid was found to obey the Arrhenius rules with R2~1 where all SBE system is thermally activated when increasing temperature. The dielectric studies of the alginate-citric acid SBE system showed a non-debye behavior based on data measured using complex permittivity (e*) and complex electrical modulus (M*) at selected temperature where there are no single relation was found in new biopolymer electrolytes system.","PeriodicalId":42980,"journal":{"name":"Makara Journal of Technology","volume":" ","pages":""},"PeriodicalIF":0.2,"publicationDate":"2019-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44975117","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}
Mismatched timing between the supply and demand of energy calls for reliable storage systems. Energy storage systems have become further significant with the widespread implementation of renewable energy. These systems can mitigate problems that are often associated with renewable energy sources such as supply unreliability while meeting the demand during peak hours. Energy can be stored in various forms, yet storage systems can be generally grouped based on their output forms, namely (i) electricity and (ii) heat or thermal energy. Electrical energy is the most convenient and effective form since it can power almost all modern devices. However, the electricity itself is vastly produced by thermodynamic cycles at a particular thermal efficiency using thermal energy from fossil fuels. Meanwhile, thermal energy for the HVAC&R and the production of hot water remains the largest portion of the building energy sector. Thermal energy can be stored in the form of sensible, latent, and thermochemical energy. This review focuses on thermochemical sorption-based energy storage systems. These systems exploit endothermic and exothermic sorption processes for charging and discharging of the thermal energy. Sorption-based storage systems exhibit huge potential due to a high energy density and their ability to store the energy at room temperature. We discuss the current state-of-the-art developments, key challenges, and future prospects of sorption-based energy systems.
{"title":"Sorption-based Energy Storage Systems: A Review","authors":"K. Thu, N. Nasruddin, S. Mitra, B. Saha","doi":"10.7454/MST.V23I1.3691","DOIUrl":"https://doi.org/10.7454/MST.V23I1.3691","url":null,"abstract":"Mismatched timing between the supply and demand of energy calls for reliable storage systems. Energy storage systems have become further significant with the widespread implementation of renewable energy. These systems can mitigate problems that are often associated with renewable energy sources such as supply unreliability while meeting the demand during peak hours. Energy can be stored in various forms, yet storage systems can be generally grouped based on their output forms, namely (i) electricity and (ii) heat or thermal energy. Electrical energy is the most convenient and effective form since it can power almost all modern devices. However, the electricity itself is vastly produced by thermodynamic cycles at a particular thermal efficiency using thermal energy from fossil fuels. Meanwhile, thermal energy for the HVAC&R and the production of hot water remains the largest portion of the building energy sector. Thermal energy can be stored in the form of sensible, latent, and thermochemical energy. This review focuses on thermochemical sorption-based energy storage systems. These systems exploit endothermic and exothermic sorption processes for charging and discharging of the thermal energy. Sorption-based storage systems exhibit huge potential due to a high energy density and their ability to store the energy at room temperature. We discuss the current state-of-the-art developments, key challenges, and future prospects of sorption-based energy systems.","PeriodicalId":42980,"journal":{"name":"Makara Journal of Technology","volume":" ","pages":""},"PeriodicalIF":0.2,"publicationDate":"2019-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43106325","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 digital rainbow hologram (DRH) is a potential next-generation three-dimensional display media for the development of modern and smart electronics devices. It is one of the methods that can support the characteristic whereby a realistic display media occupies the space that the real object would have occupied. Since a rainbow hologram records a large amount of spatial or temporal frequency component from the object that represents the rainbow spectrum, a large amount of information needs to be decoded digitally. In this paper, to reconstruct a DRH, we propose a novel method based on the modulation of red, green, and blue spectral components of light by wavelet transform (WT) in the recording and reconstruction processes, which we digitally simulated in a computer using an algorithm. In the simulations, continuous WT (CWT) was based on Haar, Daubechies, Meyer, and Coiflet wavelets with a level set to be two. Based on the results of simulations using CWT, the optimum distance between object and hologram was 30 cm, and the maximum compression was 88.55%, which was achieved with Meyer wavelet. Moreover, optimal de-noising and optimal localization of spatial frequency component based on red, green, and blue spectral components were also achieved using the proposed method.
{"title":"Wavelet Transform on Digital Rainbow Hologram based on Spectral Compression for Quality Enhancement in 3D Display Media","authors":"U. Darusalam, Panca Dewi Pamungkasari","doi":"10.7454/MST.V23I1.3107","DOIUrl":"https://doi.org/10.7454/MST.V23I1.3107","url":null,"abstract":"A digital rainbow hologram (DRH) is a potential next-generation three-dimensional display media for the development of modern and smart electronics devices. It is one of the methods that can support the characteristic whereby a realistic display media occupies the space that the real object would have occupied. Since a rainbow hologram records a large amount of spatial or temporal frequency component from the object that represents the rainbow spectrum, a large amount of information needs to be decoded digitally. In this paper, to reconstruct a DRH, we propose a novel method based on the modulation of red, green, and blue spectral components of light by wavelet transform (WT) in the recording and reconstruction processes, which we digitally simulated in a computer using an algorithm. In the simulations, continuous WT (CWT) was based on Haar, Daubechies, Meyer, and Coiflet wavelets with a level set to be two. Based on the results of simulations using CWT, the optimum distance between object and hologram was 30 cm, and the maximum compression was 88.55%, which was achieved with Meyer wavelet. Moreover, optimal de-noising and optimal localization of spatial frequency component based on red, green, and blue spectral components were also achieved using the proposed method.","PeriodicalId":42980,"journal":{"name":"Makara Journal of Technology","volume":" ","pages":""},"PeriodicalIF":0.2,"publicationDate":"2019-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47541228","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}
Oxygen scavenging active film can be used to prevent diffusion of free oxygen due to the action of permeation mechanism. In this study, biodegradable oxygen scavenging plastic film was designed by incorporating an antioxidant agent into plasticized polylactic acid or PLA-PEG (PPLA). Butylated hydroxytoluene (BHT) was added at different concentrations into the matrix of the PPLA film using a direct casting method to produce oxygen scavenging active film. The antiradical activity of the oxygen scavenging active film was observed, which could be applied for preventing vitamin C degradation in cut lemon during storage. The antiradical activity of the active film composite reduced after 4 days of storage at 28 °C. Initial antiradical activities were measured at 99.90%–99.91% after introducing 1%, 5%, and 10% concentrations of BHT into the matrix of the PPLA film. DPPH analysis indicated that a larger concentration of BHT exhibited higher antiradical activity after 4 days of storage surrounded with free oxygen. The final antiradical activities were 35.45%, 54.56%, and 81.65% at 1%, 5%, and 10% BHT concentrations, respectively. Therefore, incorporating a higher BHT fraction into the oxygen scavenging active film composite can certainly prevent the oxidation of cut lemon. The respective final vitamin C levels were 13.5%, 20.6%, and 22.5% after 4 days of storage.
{"title":"Ascorbic Acid Degradation in Cut Lemon Packaged Using Oxygen Scavenging Active Film During Storage","authors":"K. Yuniarto, S. Purwanto, B. Welt, A. Lastriyanto","doi":"10.7454/MST.V22I3.3659","DOIUrl":"https://doi.org/10.7454/MST.V22I3.3659","url":null,"abstract":"Oxygen scavenging active film can be used to prevent diffusion of free oxygen due to the action of permeation mechanism. In this study, biodegradable oxygen scavenging plastic film was designed by incorporating an antioxidant agent into plasticized polylactic acid or PLA-PEG (PPLA). Butylated hydroxytoluene (BHT) was added at different concentrations into the matrix of the PPLA film using a direct casting method to produce oxygen scavenging active film. The antiradical activity of the oxygen scavenging active film was observed, which could be applied for preventing vitamin C degradation in cut lemon during storage. The antiradical activity of the active film composite reduced after 4 days of storage at 28 °C. Initial antiradical activities were measured at 99.90%–99.91% after introducing 1%, 5%, and 10% concentrations of BHT into the matrix of the PPLA film. DPPH analysis indicated that a larger concentration of BHT exhibited higher antiradical activity after 4 days of storage surrounded with free oxygen. The final antiradical activities were 35.45%, 54.56%, and 81.65% at 1%, 5%, and 10% BHT concentrations, respectively. Therefore, incorporating a higher BHT fraction into the oxygen scavenging active film composite can certainly prevent the oxidation of cut lemon. The respective final vitamin C levels were 13.5%, 20.6%, and 22.5% after 4 days of storage.","PeriodicalId":42980,"journal":{"name":"Makara Journal of Technology","volume":" ","pages":""},"PeriodicalIF":0.2,"publicationDate":"2019-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45338955","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}
Pollution caused by industrial wastewater containing heavy metals is a major issue, primarily due to its toxic nature. A cheap yet effective method to deal with such wastewater is activated carbon adsorption. The purpose of this research is to evaluate and design a fixed bed adsorber with granular activated carbon as an adsorbent to process wastewatercontaining chromium hexavalent (Cr ). Experiments show that the Langmuir isotherm fits the equilibrium data as effectively as the Freundlich isotherm. Activated carbon used in this research is Jacobi 2000 derived from bituminous coal. The lab scale inlet volumetric flow is 100 mL/h with different Cr concentration for each run, 20 and 35 ppm respectively. Based on scale-up calculation with Length of Unused Bed (LUB) method, for superficial flow of 400 L.m .min and service time of six months, the column dimensions for inlet concentration of 20 ppm are 0.62 m diameter and 2.33 m height with 1.87 m carbon bed depth. Concurrently, a slightly bigger column (0.63 m diameter and 2.37 m height column with 1.89 m carbon bed) is necessary for treating inlet concentration of 35 ppm.
{"title":"Activated Carbon Fixed-Bed Adsorber Design for Treating Chromium Hexavalent Wastewater","authors":"T. Hudaya, Velicia Rachmat","doi":"10.7454/MST.V22I3.3483","DOIUrl":"https://doi.org/10.7454/MST.V22I3.3483","url":null,"abstract":"Pollution caused by industrial wastewater containing heavy metals is a major issue, primarily due to its toxic nature. A cheap yet effective method to deal with such wastewater is activated carbon adsorption. The purpose of this research is to evaluate and design a fixed bed adsorber with granular activated carbon as an adsorbent to process wastewatercontaining chromium hexavalent (Cr ). Experiments show that the Langmuir isotherm fits the equilibrium data as effectively as the Freundlich isotherm. Activated carbon used in this research is Jacobi 2000 derived from bituminous coal. The lab scale inlet volumetric flow is 100 mL/h with different Cr concentration for each run, 20 and 35 ppm respectively. Based on scale-up calculation with Length of Unused Bed (LUB) method, for superficial flow of 400 L.m .min and service time of six months, the column dimensions for inlet concentration of 20 ppm are 0.62 m diameter and 2.33 m height with 1.87 m carbon bed depth. Concurrently, a slightly bigger column (0.63 m diameter and 2.37 m height column with 1.89 m carbon bed) is necessary for treating inlet concentration of 35 ppm.","PeriodicalId":42980,"journal":{"name":"Makara Journal of Technology","volume":" ","pages":""},"PeriodicalIF":0.2,"publicationDate":"2019-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47563729","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}
This research objective is to convert heat from the radiator fluid of a diesel engine to electrical energy by utilizing a thermoelectric generator (TEG). The TEG consists of 20 semiconductors (TE modules) and is equipped with a heat sink. The research shows that using the TEG, the heat of radiator fluid can be converted to electrical energy, although the electricity generated is small. The maximum electrical voltage generated by the TEG when modules were connected in series was 10 volts. When the TE modules were connected in parallel and series-parallel, the maximum voltages generated were 2.11 and 2.53 volts, respectively. The maximum electric current generated by the TEG when the modules were connected in series-parallel was 128 mA. When the modules were connected in series and parallel, the maximum electrical currents generated were 108.3 and 69.7 mA, respectively. The series circuit is the best choice for the TEG because it produced the highest electrical power. The TEG efficiency in this study was 5%–7.1%. The voltage and electric current generated by the TEG will be higher if the temperature difference between the hot and cold sides of the semiconductor is higher. The use of this TEG did not reduce the performance of the test engine cooling system or radiator system.
{"title":"Conversion of Heat Energy from Cooling Water of Diesel Engine to Electrical Energy Using Thermoelectric Generator","authors":"Muhammad Hasan Albana","doi":"10.7454/MST.V22I3.3521","DOIUrl":"https://doi.org/10.7454/MST.V22I3.3521","url":null,"abstract":"This research objective is to convert heat from the radiator fluid of a diesel engine to electrical energy by utilizing a thermoelectric generator (TEG). The TEG consists of 20 semiconductors (TE modules) and is equipped with a heat sink. The research shows that using the TEG, the heat of radiator fluid can be converted to electrical energy, although the electricity generated is small. The maximum electrical voltage generated by the TEG when modules were connected in series was 10 volts. When the TE modules were connected in parallel and series-parallel, the maximum voltages generated were 2.11 and 2.53 volts, respectively. The maximum electric current generated by the TEG when the modules were connected in series-parallel was 128 mA. When the modules were connected in series and parallel, the maximum electrical currents generated were 108.3 and 69.7 mA, respectively. The series circuit is the best choice for the TEG because it produced the highest electrical power. The TEG efficiency in this study was 5%–7.1%. The voltage and electric current generated by the TEG will be higher if the temperature difference between the hot and cold sides of the semiconductor is higher. The use of this TEG did not reduce the performance of the test engine cooling system or radiator system.","PeriodicalId":42980,"journal":{"name":"Makara Journal of Technology","volume":" ","pages":""},"PeriodicalIF":0.2,"publicationDate":"2019-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48309230","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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