Pub Date : 2022-07-31DOI: 10.21924/cst.7.1.2022.676
Alvin Sahroni, Faizal Mahananto, H. Zakaria, Hendra Setiawan
The cortisol and norepinephrine from human salivary can represent psychological conditions. A portable salivary amylase monitor device (sAA) has existed; however, how the sAA corresponds to the central nervous system changes is still limited to carry out. Twenty university students aged between 20 and 22 years participated in which they played a stressful computer game during the experiment. Nineteen EEG electrodes were attached to the head scalp while the relative power on the delta, theta, alpha, and beta-band was calculated. The sAA value was obtained using a portable device called Nipro Cocorometer from Japan. The sAA levels and the brain's relative band power increased. Beta waves of the brain's right hemisphere were found higher than that of the left hemisphere, especially on the right temporal (T4, p < 0.01). Then, we concluded that the beta-band power on the right hemisphere corresponds to wthe sAA changes.
{"title":"EEG band power analysis corresponding to salivary amylase activity during stressful computer gameplay","authors":"Alvin Sahroni, Faizal Mahananto, H. Zakaria, Hendra Setiawan","doi":"10.21924/cst.7.1.2022.676","DOIUrl":"https://doi.org/10.21924/cst.7.1.2022.676","url":null,"abstract":"The cortisol and norepinephrine from human salivary can represent psychological conditions. A portable salivary amylase monitor device (sAA) has existed; however, how the sAA corresponds to the central nervous system changes is still limited to carry out. Twenty university students aged between 20 and 22 years participated in which they played a stressful computer game during the experiment. Nineteen EEG electrodes were attached to the head scalp while the relative power on the delta, theta, alpha, and beta-band was calculated. The sAA value was obtained using a portable device called Nipro Cocorometer from Japan. The sAA levels and the brain's relative band power increased. Beta waves of the brain's right hemisphere were found higher than that of the left hemisphere, especially on the right temporal (T4, p < 0.01). Then, we concluded that the beta-band power on the right hemisphere corresponds to wthe sAA changes.","PeriodicalId":36437,"journal":{"name":"Communications in Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46662984","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 : 2022-07-31DOI: 10.21924/cst.7.1.2022.667
J. Sagar, G. Madhu, J. Koteswararao, P. Dixit
The present study purposely is to study the properties of TiO2-epoxy composites. TiO2 was synthesized using the peptization and hydrolysis method and the synthesized powder is in anatase form. The present work aimed to develop the low TiO2 filler epoxy composites for the improved thermal and mechanical properties. The synthesized TiO2 was used as a filler along with epoxy composite and the epoxy - TiO2 nanocomposites were fabricated using the low filler concentration of 0.5, 1.0, 1.5, 2.0, and 2.5% by weight. The glass transition temperature (Tg), regardless of the nanoparticles, was almost the same at 71.23oC. Tensile strength was maximum at 0.5%wt.; further increase in filler loading resulted in a linear reduction of tensile strength. Tensile modulus increased linearly and was found to be maximum at 2.5wt%. Meanwhile, compressive strength was maximum at 0.5%, and compressive modulus increased with filler increase. The present work mainly aimed to develop low filler concentrations.
{"title":"Studies on thermal and mechanical behavior of nano TiO2 - epoxy polymer composite","authors":"J. Sagar, G. Madhu, J. Koteswararao, P. Dixit","doi":"10.21924/cst.7.1.2022.667","DOIUrl":"https://doi.org/10.21924/cst.7.1.2022.667","url":null,"abstract":"The present study purposely is to study the properties of TiO2-epoxy composites. TiO2 was synthesized using the peptization and hydrolysis method and the synthesized powder is in anatase form. The present work aimed to develop the low TiO2 filler epoxy composites for the improved thermal and mechanical properties. The synthesized TiO2 was used as a filler along with epoxy composite and the epoxy - TiO2 nanocomposites were fabricated using the low filler concentration of 0.5, 1.0, 1.5, 2.0, and 2.5% by weight. The glass transition temperature (Tg), regardless of the nanoparticles, was almost the same at 71.23oC. Tensile strength was maximum at 0.5%wt.; further increase in filler loading resulted in a linear reduction of tensile strength. Tensile modulus increased linearly and was found to be maximum at 2.5wt%. Meanwhile, compressive strength was maximum at 0.5%, and compressive modulus increased with filler increase. The present work mainly aimed to develop low filler concentrations.","PeriodicalId":36437,"journal":{"name":"Communications in Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42422579","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 : 2022-07-31DOI: 10.21924/cst.7.1.2022.727
T. Yuwono, M. Baharuddin, N. Misran, M. Ismail, M. F. Mansor
Nowadays, electronic products are being used extensively in many fields and applications. The dense population of electronic devices in human life has become a challenge for microwave engineers to ensure that their products can meet the Electromagnetic Compatibility (EMC) standards. Complex electronic products with smaller sizes and denser components will be a challenge for compliance with EMC standards. In addition, the occurrence of non-stationary emission at certain operating modes becomes a challenge for analysis. Error in analyzing EM emissions will make the products unable to meet the requirements of EMC standards; hence, they will be prohibited to be marketed. Currently, there are two methods of emission analysis, i.e. by measurement and modeling or computation. There are some problems, however, in the analysis of EM emissions regarding the area of test, complexity, DUT positioning error, installation cost, and time consumption. In this paper, the analysis techniques for EM emissions including Open Area Test Site (OATS), Anechoic chamber, Transverse Electromagnetics TEM Cell, Compact Antenna Test Range (CATR) and near field scanning are reviewed comprehensively. This survey covered EMC standards, principles of EM emission measurement techniques, advantages and disadvantages of EM emission measurement techniques, studies and applications of each technique, recommendations for which technique to be used, and challenges for future research in EM emission measurement. The final section of this paper discusses the challenges for near-field measurements related to the non-stationary emissions phenomenon. This papers also presents the challenges of how to detect and characterize them.
{"title":"A review of measurement of electromagnetic emission in electronic product: Techniques and challenges","authors":"T. Yuwono, M. Baharuddin, N. Misran, M. Ismail, M. F. Mansor","doi":"10.21924/cst.7.1.2022.727","DOIUrl":"https://doi.org/10.21924/cst.7.1.2022.727","url":null,"abstract":"Nowadays, electronic products are being used extensively in many fields and applications. The dense population of electronic devices in human life has become a challenge for microwave engineers to ensure that their products can meet the Electromagnetic Compatibility (EMC) standards. Complex electronic products with smaller sizes and denser components will be a challenge for compliance with EMC standards. In addition, the occurrence of non-stationary emission at certain operating modes becomes a challenge for analysis. Error in analyzing EM emissions will make the products unable to meet the requirements of EMC standards; hence, they will be prohibited to be marketed. Currently, there are two methods of emission analysis, i.e. by measurement and modeling or computation. There are some problems, however, in the analysis of EM emissions regarding the area of test, complexity, DUT positioning error, installation cost, and time consumption. In this paper, the analysis techniques for EM emissions including Open Area Test Site (OATS), Anechoic chamber, Transverse Electromagnetics TEM Cell, Compact Antenna Test Range (CATR) and near field scanning are reviewed comprehensively. This survey covered EMC standards, principles of EM emission measurement techniques, advantages and disadvantages of EM emission measurement techniques, studies and applications of each technique, recommendations for which technique to be used, and challenges for future research in EM emission measurement. The final section of this paper discusses the challenges for near-field measurements related to the non-stationary emissions phenomenon. This papers also presents the challenges of how to detect and characterize them.","PeriodicalId":36437,"journal":{"name":"Communications in Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42197774","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 : 2022-07-31DOI: 10.21924/cst.7.1.2022.669
D. Lestari, A. T. Yuliansyah, A. Budiman
Toxicity of methylene blue (MB) in water bodies has a negative effect on environment and living organisms. The presence of MB in water could last longer in view of the non-biodegradable characteristic. In this study, hydrochar was used as adsorbent to remove MB from aqueous solution. Hydrochar derived from bagasse was successfully prepared by hydrothermal carbonization treatment at temperature of 270oC, and pressure of 10 Bar for 30 minutes. For enhancing the adsorption ability, hydrochar was activated by adding KOH that was able to increase the percent removal by ~11%. The hydrochar was characterized using FTIR before and after adsorption. The results showed that the dominant functional groups of hydrochar included O-H, C=O, -O- and aromatic compounds. Whereas, the functional group of azo groups such as N-H and N=N appeared after adsorption. The maximum adsorption capacity (Qmax) was 5.1204 mg/g, while the adsorption isotherm of MB onto hydrochar followed the Langmuir and Freundlich model. The adsorption mechanism belongs to chemical adsorption, and the rate of diffusion can be neglected because the adsorption kinetics fitted well with pseudo-second order and the value of k2 > kdif > k1. Thermodynamic studies indicated that the adsorption process is classified as endothermic and reversible at room temperature. The results showed that hydrochar could be the alternative adsorbent for removing MB in wastewater. In addition, sugarcane bagasse has a great potential as feedstock of hydrochar.
{"title":"Adsorption studies of KOH-modified hydrochar derived from sugarcane bagasse for dye removal: Kinetic, isotherm, and thermodynamic study","authors":"D. Lestari, A. T. Yuliansyah, A. Budiman","doi":"10.21924/cst.7.1.2022.669","DOIUrl":"https://doi.org/10.21924/cst.7.1.2022.669","url":null,"abstract":"Toxicity of methylene blue (MB) in water bodies has a negative effect on environment and living organisms. The presence of MB in water could last longer in view of the non-biodegradable characteristic. In this study, hydrochar was used as adsorbent to remove MB from aqueous solution. Hydrochar derived from bagasse was successfully prepared by hydrothermal carbonization treatment at temperature of 270oC, and pressure of 10 Bar for 30 minutes. For enhancing the adsorption ability, hydrochar was activated by adding KOH that was able to increase the percent removal by ~11%. The hydrochar was characterized using FTIR before and after adsorption. The results showed that the dominant functional groups of hydrochar included O-H, C=O, -O- and aromatic compounds. Whereas, the functional group of azo groups such as N-H and N=N appeared after adsorption. The maximum adsorption capacity (Qmax) was 5.1204 mg/g, while the adsorption isotherm of MB onto hydrochar followed the Langmuir and Freundlich model. The adsorption mechanism belongs to chemical adsorption, and the rate of diffusion can be neglected because the adsorption kinetics fitted well with pseudo-second order and the value of k2 > kdif > k1. Thermodynamic studies indicated that the adsorption process is classified as endothermic and reversible at room temperature. The results showed that hydrochar could be the alternative adsorbent for removing MB in wastewater. In addition, sugarcane bagasse has a great potential as feedstock of hydrochar.","PeriodicalId":36437,"journal":{"name":"Communications in Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46725725","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 : 2022-07-31DOI: 10.21924/cst.7.1.2022.851
N. Palapa, A. Badri, Mardiyanto, R. Mohadi, T. Taher, A. Lesbani
Mg/Cr layered double hydroxide (LDH) was prepared and modified using an intercalation of oxalate anions ((COO)22-) to form Mg/Cr-(COO)22. The materials were then investigated to malachite green removal to determine the adsorption ability. Furthermore, the desorption process and regeneration of adsorbent were systematically conducted. The adsorption of green malachite on Mg/Cr- LDH and Mg/Cr-(COO)22- materials fitted to the pseudo-second-order (PSO) kinetic model and Freundlich isotherm model with an adsorption capacity of 33.784 mg/g (333K) for Mg/Cr LDH and 64.516 mg/g (333K) for Mg/Cr-(COO)22-. Thermodynamic data showed that the adsorption process was spontaneous and endothermic. Also, the appropriate reagent desorption study was found as hydrochloric acid and material regeneration studies exhibited a good recycling performance after 3 times cycles and, the Mg/Cr-oxalate showed a good performance for malachite green adsorption. It can be concluded that Mg/Cr--(COO)22- can adsorb the dye stuffs effectively.
制备了Mg/Cr层状双氢氧化物(LDH)，并通过插入草酸盐阴离子((COO)22-)对其进行了改性，得到Mg/Cr-(COO)22。然后考察了材料对孔雀石绿的去除效果，以确定其吸附能力。并对吸附剂的解吸过程和再生过程进行了系统的研究。绿孔雀石对Mg/Cr- LDH和Mg/Cr-(COO)22-材料的吸附符合拟二阶动力学模型和Freundlich等温模型，对Mg/Cr- LDH和Mg/Cr-(COO)22-的吸附量分别为33.784 Mg/ g (333K)和64.516 Mg/ g (333K)。热力学数据表明，吸附过程是自发的吸热过程。此外，还发现了合适的试剂解吸研究，盐酸和材料再生研究在3次循环后表现出良好的回收性能，Mg/ cr -草酸盐对孔雀石绿的吸附表现出良好的性能。结果表明，Mg/Cr—(COO)22-能有效吸附染料。
{"title":"Mg/Cr-(COO)22- layered double hydroxide for malachite green removal","authors":"N. Palapa, A. Badri, Mardiyanto, R. Mohadi, T. Taher, A. Lesbani","doi":"10.21924/cst.7.1.2022.851","DOIUrl":"https://doi.org/10.21924/cst.7.1.2022.851","url":null,"abstract":"Mg/Cr layered double hydroxide (LDH) was prepared and modified using an intercalation of oxalate anions ((COO)22-) to form Mg/Cr-(COO)22. The materials were then investigated to malachite green removal to determine the adsorption ability. Furthermore, the desorption process and regeneration of adsorbent were systematically conducted. The adsorption of green malachite on Mg/Cr- LDH and Mg/Cr-(COO)22- materials fitted to the pseudo-second-order (PSO) kinetic model and Freundlich isotherm model with an adsorption capacity of 33.784 mg/g (333K) for Mg/Cr LDH and 64.516 mg/g (333K) for Mg/Cr-(COO)22-. Thermodynamic data showed that the adsorption process was spontaneous and endothermic. Also, the appropriate reagent desorption study was found as hydrochloric acid and material regeneration studies exhibited a good recycling performance after 3 times cycles and, the Mg/Cr-oxalate showed a good performance for malachite green adsorption. It can be concluded that Mg/Cr--(COO)22- can adsorb the dye stuffs effectively.","PeriodicalId":36437,"journal":{"name":"Communications in Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47871752","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 : 2022-07-31DOI: 10.21924/cst.7.1.2022.739
Suatmi Murnani, N. A. Setiawan, S. Wibirama
Human gaze is a promising input modality for being able to be used as natural user interface in touchless technology during Covid-19 pandemic. Spontaneous gaze interaction is required to allow participants to directly interact with an application without any prior eye tracking calibration. Smooth pursuit eye movement is commonly used in this kind of spontaneous gaze-based interaction. Many studies have been focused on various object selection techniques in smooth pursuit-based gaze interaction; however, challenges in spatial accuracy and implementation complexity have not been resolved yet. To address these problems, we then proposed an approach using difference patterns between gaze and dynamic objects' trajectories for object selection named Difference Gaze Pattern method (DGP). Based on the experimental results, our proposed method yielded the best object selection accuracy of and success time of ms. The experimental results also showed the robustness of object selection using difference patterns to spatial accuracy and it was relatively simpler to be implemented. The results also suggested that our proposed method can contribute to spontaneous gaze interaction.
{"title":"Spontaneous gaze interaction based on smooth pursuit eye movement using difference gaze pattern method","authors":"Suatmi Murnani, N. A. Setiawan, S. Wibirama","doi":"10.21924/cst.7.1.2022.739","DOIUrl":"https://doi.org/10.21924/cst.7.1.2022.739","url":null,"abstract":"Human gaze is a promising input modality for being able to be used as natural user interface in touchless technology during Covid-19 pandemic. Spontaneous gaze interaction is required to allow participants to directly interact with an application without any prior eye tracking calibration. Smooth pursuit eye movement is commonly used in this kind of spontaneous gaze-based interaction. Many studies have been focused on various object selection techniques in smooth pursuit-based gaze interaction; however, challenges in spatial accuracy and implementation complexity have not been resolved yet. To address these problems, we then proposed an approach using difference patterns between gaze and dynamic objects' trajectories for object selection named Difference Gaze Pattern method (DGP). Based on the experimental results, our proposed method yielded the best object selection accuracy of and success time of ms. The experimental results also showed the robustness of object selection using difference patterns to spatial accuracy and it was relatively simpler to be implemented. The results also suggested that our proposed method can contribute to spontaneous gaze interaction.","PeriodicalId":36437,"journal":{"name":"Communications in Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47600257","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-12-31DOI: 10.21924/cst.6.2.2021.556
F. N. Budiman, A. Rushdi
Partial discharges (PDs) constitute important phenomena in a Gas-Insulated System (GIS) that warrant recognition (and, subsequently, mitigation) as they are obvious symptoms of system degradation. This paper proposes the application of dimensional analysis, based on Buckingham pi theorem, for characterizing PDs provoked by the presence of metallic particles adhering to the spacer surface in a GIS employing SF6 (Sulphur hexafluoride). The ultimate goal of the analysis is to formulate the relationships that express three PD indicator quantities, namely current, charge, and energy, in terms of six independent quantities that collectively influence these indicators. These six quantities (henceforth referred to as the influencing, determining or affecting variables) include the level of applied voltage, the SF6 pressure, the length and position of the particle on the spacer, the duration of voltage application, and the gap between electrodes. To compute the pertinent dimensionless products, we implement three computational methods based on matrix operations. These three methods produce exactly the same dimensionless products, which are subsequently used for constructing the models depicting the relationships between each of the three PD dependent quantities and the common six determining variables. The models derived provide partial quantitative information and facilitate qualitative reasoning about the considered phenomenon.
{"title":"Dimensional analysis of partial discharge initiated by a metallic particle adhering to the spacer surface in a gas-insulated system","authors":"F. N. Budiman, A. Rushdi","doi":"10.21924/cst.6.2.2021.556","DOIUrl":"https://doi.org/10.21924/cst.6.2.2021.556","url":null,"abstract":"Partial discharges (PDs) constitute important phenomena in a Gas-Insulated System (GIS) that warrant recognition (and, subsequently, mitigation) as they are obvious symptoms of system degradation. This paper proposes the application of dimensional analysis, based on Buckingham pi theorem, for characterizing PDs provoked by the presence of metallic particles adhering to the spacer surface in a GIS employing SF6 (Sulphur hexafluoride). The ultimate goal of the analysis is to formulate the relationships that express three PD indicator quantities, namely current, charge, and energy, in terms of six independent quantities that collectively influence these indicators. These six quantities (henceforth referred to as the influencing, determining or affecting variables) include the level of applied voltage, the SF6 pressure, the length and position of the particle on the spacer, the duration of voltage application, and the gap between electrodes. To compute the pertinent dimensionless products, we implement three computational methods based on matrix operations. These three methods produce exactly the same dimensionless products, which are subsequently used for constructing the models depicting the relationships between each of the three PD dependent quantities and the common six determining variables. The models derived provide partial quantitative information and facilitate qualitative reasoning about the considered phenomenon.","PeriodicalId":36437,"journal":{"name":"Communications in Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42240844","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-12-31DOI: 10.21924/cst.6.2.2021.460
P. Mardina, H. Wijayanti, A. Tuhuloula, Erita Hijriyati, Sarifah
The utilization of an appropriate catalyst in biodiesel production depends on the free fatty acid content of vegetable oil as a feedstock. Recently, heterogeneous acid catalysts are widely chosen for biodiesel production. However, these catalysts are non-renewable, highly expensive and low stability. Due to the aforementioned drawbacks of commercial heterogeneous acid catalyst, a number of efforts have been made to develop renewable green solid acid catalysts derived from biomass. Published literature revealed that the application of the biomass derived solid acid catalysts can achieve up to 98% yield of biodiesel. This article focused on corncob as raw material in solid acid catalyst preparation for biodiesel production. The efficient preparation method and performance comparation are discussed here. The corncob derived heterogeneous acid catalysts provides an environmentally friendly and green synthesis for biodiesel production.
{"title":"Corncob residue as heterogeneous acid catalyst for green synthesis of biodiesel: A short review","authors":"P. Mardina, H. Wijayanti, A. Tuhuloula, Erita Hijriyati, Sarifah","doi":"10.21924/cst.6.2.2021.460","DOIUrl":"https://doi.org/10.21924/cst.6.2.2021.460","url":null,"abstract":"The utilization of an appropriate catalyst in biodiesel production depends on the free fatty acid content of vegetable oil as a feedstock. Recently, heterogeneous acid catalysts are widely chosen for biodiesel production. However, these catalysts are non-renewable, highly expensive and low stability. Due to the aforementioned drawbacks of commercial heterogeneous acid catalyst, a number of efforts have been made to develop renewable green solid acid catalysts derived from biomass. Published literature revealed that the application of the biomass derived solid acid catalysts can achieve up to 98% yield of biodiesel. This article focused on corncob as raw material in solid acid catalyst preparation for biodiesel production. The efficient preparation method and performance comparation are discussed here. The corncob derived heterogeneous acid catalysts provides an environmentally friendly and green synthesis for biodiesel production.","PeriodicalId":36437,"journal":{"name":"Communications in Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48608163","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-12-31DOI: 10.21924/cst.6.2.2021.515
N. Chuong
This research found the great hold of liming, soils and irrigation water on the arsenic (As) accumulation of rice, maize and mung bean in the nethouse research. Two greenhouse experiments had various plant types of rice, maize and mung bean with two soils inside and outside the dyke, two irrigated waters of 0.0 and 200 ?g As/L and three different lime ratios (0, 7.0 and 9.0 tons CaO/ha). The whole treatments were twenty one (12 treatments of experiment 1 and 9 of experiment 2) with 4 repetitions. The results of this study showed that the lime application raised both soil pH and crop yield. The arsenic (As) absorption of plant bodies in stems and seeds inside the dyke increased from 67.8 to 68.3% higher than those outside the dyke, respectively. The arsenic contents of stems and seeds with the treatments of 200 ?g As/L irrigation water were higher from 81.5 to 89.4% than that of non As irrigation water, respectively. The lime supplementation of 7.0 and 9.0 tons CaO per ha reduced the As accumulation of stems and seeds of rice, maize and mung bean was lower than the one without lime supplement from 38.6 (stems) and 54.5 (seeds). Mung bean absorbed the highest As, followed by rice and maize with the lowest As value. However, the lime supplementation of 9.0 tons CaO/ha had so high soil pH of soil that restricted the growth and yield of crops. More different lime concentrations need to search for more new details and new discovery of positive effects of this research.
{"title":"The influences of lime and irrigation water on arsenic accumulation of rice, maize and mungbean in the nethouse condition","authors":"N. Chuong","doi":"10.21924/cst.6.2.2021.515","DOIUrl":"https://doi.org/10.21924/cst.6.2.2021.515","url":null,"abstract":"This research found the great hold of liming, soils and irrigation water on the arsenic (As) accumulation of rice, maize and mung bean in the nethouse research. Two greenhouse experiments had various plant types of rice, maize and mung bean with two soils inside and outside the dyke, two irrigated waters of 0.0 and 200 ?g As/L and three different lime ratios (0, 7.0 and 9.0 tons CaO/ha). The whole treatments were twenty one (12 treatments of experiment 1 and 9 of experiment 2) with 4 repetitions. The results of this study showed that the lime application raised both soil pH and crop yield. The arsenic (As) absorption of plant bodies in stems and seeds inside the dyke increased from 67.8 to 68.3% higher than those outside the dyke, respectively. The arsenic contents of stems and seeds with the treatments of 200 ?g As/L irrigation water were higher from 81.5 to 89.4% than that of non As irrigation water, respectively. The lime supplementation of 7.0 and 9.0 tons CaO per ha reduced the As accumulation of stems and seeds of rice, maize and mung bean was lower than the one without lime supplement from 38.6 (stems) and 54.5 (seeds). Mung bean absorbed the highest As, followed by rice and maize with the lowest As value. However, the lime supplementation of 9.0 tons CaO/ha had so high soil pH of soil that restricted the growth and yield of crops. More different lime concentrations need to search for more new details and new discovery of positive effects of this research.","PeriodicalId":36437,"journal":{"name":"Communications in Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49442705","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-12-31DOI: 10.21924/cst.6.2.2021.540
Y. Arifin, M. Arsyad, Jeane Monica, S. Agus
Water containing sulfuric acid with a pH up to 3 is prevalent in swampy areas. This article focuses on the effects of the solution on volume change of compacted claystone?bentonite mixture. Claystone was obtained from Banjarbakula landfill and it was mixed with bentonite on a 5, 10, 15, and 20% dry mass basis. Samples possessed the dry density of 16 kN/m3 and moisture content of 10, 15, and 20%. The odometer examined the samples' swelling and compression in both pure and acidic water. Characterization tests i.e., XRF, XRD, and FTIR were also performed. The results showed that swelling and compression were affected by initial moisture and bentonite content. Samples with a moisture content of 20% showed compression in acidic water. Acidic water changed the water absorbed on the clay surface without altering the mineral. A mixture containing 20% bentonite compacted to optimum moisture content was found at best in reducing the acidic water effects.
{"title":"Volume change in compacted claystone-bentonite mixtures as affected by the swamp acidic water","authors":"Y. Arifin, M. Arsyad, Jeane Monica, S. Agus","doi":"10.21924/cst.6.2.2021.540","DOIUrl":"https://doi.org/10.21924/cst.6.2.2021.540","url":null,"abstract":"Water containing sulfuric acid with a pH up to 3 is prevalent in swampy areas. This article focuses on the effects of the solution on volume change of compacted claystone?bentonite mixture. Claystone was obtained from Banjarbakula landfill and it was mixed with bentonite on a 5, 10, 15, and 20% dry mass basis. Samples possessed the dry density of 16 kN/m3 and moisture content of 10, 15, and 20%. The odometer examined the samples' swelling and compression in both pure and acidic water. Characterization tests i.e., XRF, XRD, and FTIR were also performed. The results showed that swelling and compression were affected by initial moisture and bentonite content. Samples with a moisture content of 20% showed compression in acidic water. Acidic water changed the water absorbed on the clay surface without altering the mineral. A mixture containing 20% bentonite compacted to optimum moisture content was found at best in reducing the acidic water effects.","PeriodicalId":36437,"journal":{"name":"Communications in Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42326412","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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