Pub Date : 2023-06-30DOI: 10.55766/sujst-2023-01-e01613
Haydar Ataelmanan Ali Mohamed, Sitti Asmah Hassan, Othman Che Puan, Tareq Mohamed Al-Bahr, Shaza Farouk Azhari
Lane change (LC) manoeuvre has been recognized as an important aspect of driving behavior that significantly impacts traffic operation and management. Incorrect LC execution, particularly incorrect gap distance selection before the LC movement, can lead to traffic accidents, most often in the form of a rear-end, sideswipe, or angled collision. This paper investigates the relationship between time to collision and the speed differential between the leading and following vehicles when lane change occurs. Using an instrumented vehicle method, data was gathered along a typical length of the Kuala Lumpur-Seremban expressway. A VBox (Video Velocity Box) is an on-board data collection device that is used to videotape traffic incidents on the road, was installed in a passenger car. In a three-day period, a total of 175 instances of lane changing were documented. Following gap distance was used to calibrate the VBox equipment as a measure of efficiency. A simple linear regression was conducted between time to collision (TTC) and speed differential. It was found that 60% and 75% of drivers have TTC fewer than 5 sec and 10 sec, separately, with 6.10 sec average TTC. The time to collision (TTC) has a negative linear relationship with speed differential (R2 = 84.47%). The finding shows that the higher the speed differential between vehicles, the lower the TTC value, which indicates a higher probability of collisions. It can be concluded that the speed differential between the test car and following vehicles is affecting the TTC, which is to be utilised as a risk indicator throughout lane-changing operation.
{"title":"THE RELATIONSHIP BETWEEN SPEED DIFFERENTIAL AND TIME TO COLLISION OF MALAYSIAN EXPRESSWAYS","authors":"Haydar Ataelmanan Ali Mohamed, Sitti Asmah Hassan, Othman Che Puan, Tareq Mohamed Al-Bahr, Shaza Farouk Azhari","doi":"10.55766/sujst-2023-01-e01613","DOIUrl":"https://doi.org/10.55766/sujst-2023-01-e01613","url":null,"abstract":"Lane change (LC) manoeuvre has been recognized as an important aspect of driving behavior that significantly impacts traffic operation and management. Incorrect LC execution, particularly incorrect gap distance selection before the LC movement, can lead to traffic accidents, most often in the form of a rear-end, sideswipe, or angled collision. This paper investigates the relationship between time to collision and the speed differential between the leading and following vehicles when lane change occurs. Using an instrumented vehicle method, data was gathered along a typical length of the Kuala Lumpur-Seremban expressway. A VBox (Video Velocity Box) is an on-board data collection device that is used to videotape traffic incidents on the road, was installed in a passenger car. In a three-day period, a total of 175 instances of lane changing were documented. Following gap distance was used to calibrate the VBox equipment as a measure of efficiency. A simple linear regression was conducted between time to collision (TTC) and speed differential. It was found that 60% and 75% of drivers have TTC fewer than 5 sec and 10 sec, separately, with 6.10 sec average TTC. The time to collision (TTC) has a negative linear relationship with speed differential (R2 = 84.47%). The finding shows that the higher the speed differential between vehicles, the lower the TTC value, which indicates a higher probability of collisions. It can be concluded that the speed differential between the test car and following vehicles is affecting the TTC, which is to be utilised as a risk indicator throughout lane-changing operation.","PeriodicalId":43478,"journal":{"name":"Suranaree Journal of Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136300178","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 : 2023-06-30DOI: 10.55766/sujst-2023-01-e01617
Muhammad Azam, Muhammad Nadeem, Sitti Asmah Hassan, Othman Che Puan
The unsolicited delays and unpredictable travel times are common in urban areas of Pakistan hence making it difficult to maintain the image of public transport. Bus priorities provided in terms of dedicated bus lanes at intersections are considered as a solution to improve the conditions for public transport. Conversely, dedicated lanes may negatively affect the performance of other vehicular classes. This study quantifies the impact of Bus Only Lanes (BOLs) on the intersection’s performance as well as on the performance of individual vehicular class. The VISSIM microsimulation tool was employed to a signalized intersection located in urban area under heterogeneous traffic conditions. Sensitivity analysis followed by trial and error method was conducted to calibrate the microsimulation model. The calibrated VISSIM model was utilized to run three scenarios; scenario-1: existing conditions, scenario-2: converting existing lanes to BOLs and scenario-3: providing additional lanes as BOLs. The results indicated that for scenario-2, buses experience 14-16% lesser travel time and 10.5% reduction in delays as compared to scenario-1 due to dedicated right-of-way, while all other vehicular classes experience deteriorated conditions. Scenario-2 affected the intersection’s performance and caused an increase of 5.6% in average delay, 9.0% in average maximum queue length and reduction in average speed by 9.8%. However, in scenario-3, BOLs as additional lanes improved the conditions for buses and also reduced the travel time and delays for other vehicular classes. It is established that the present findings may assist the planners and decision makers to revisit the policies for public transport services.
{"title":"IMPACTS OF BUS ONLY LANES ON SIGNALIZED INTERSECTION UNDER HETEROGENEOUS TRAFFIC CONDITIONS","authors":"Muhammad Azam, Muhammad Nadeem, Sitti Asmah Hassan, Othman Che Puan","doi":"10.55766/sujst-2023-01-e01617","DOIUrl":"https://doi.org/10.55766/sujst-2023-01-e01617","url":null,"abstract":"The unsolicited delays and unpredictable travel times are common in urban areas of Pakistan hence making it difficult to maintain the image of public transport. Bus priorities provided in terms of dedicated bus lanes at intersections are considered as a solution to improve the conditions for public transport. Conversely, dedicated lanes may negatively affect the performance of other vehicular classes. This study quantifies the impact of Bus Only Lanes (BOLs) on the intersection’s performance as well as on the performance of individual vehicular class. The VISSIM microsimulation tool was employed to a signalized intersection located in urban area under heterogeneous traffic conditions. Sensitivity analysis followed by trial and error method was conducted to calibrate the microsimulation model. The calibrated VISSIM model was utilized to run three scenarios; scenario-1: existing conditions, scenario-2: converting existing lanes to BOLs and scenario-3: providing additional lanes as BOLs. The results indicated that for scenario-2, buses experience 14-16% lesser travel time and 10.5% reduction in delays as compared to scenario-1 due to dedicated right-of-way, while all other vehicular classes experience deteriorated conditions. Scenario-2 affected the intersection’s performance and caused an increase of 5.6% in average delay, 9.0% in average maximum queue length and reduction in average speed by 9.8%. However, in scenario-3, BOLs as additional lanes improved the conditions for buses and also reduced the travel time and delays for other vehicular classes. It is established that the present findings may assist the planners and decision makers to revisit the policies for public transport services.","PeriodicalId":43478,"journal":{"name":"Suranaree Journal of Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136300174","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 : 2023-06-23DOI: 10.55766/sujst-2023-02-e01536
J. Chokboribal, Aksarapaksorn Vipavin, Aiyada Sirinjullapong, V. Suchaiya, Narongrit Lahpun
The main component of mucilage found in the fruit of okra (Abelmoschus esculentus) is okra gum consisting of pectic polysaccharides reported to exhibit, inter alia, antibacterial and antioxidant characteristics. It was used in the pharmaceutical industry, e.g. as a stabilizer or a modifier drug release. In this work, various formulations of xanthan gum (XG)/κ-carrageenan (CN)-based hydrogel with okra mucilage (OM) powder were examined to achieve the goal of developing OM-hydrogel pads that make good use of the advantages of OM polysaccharides relevant to drug delivery and/or stability. A straightforward cosmeceutical application of the OM-hydrogels is as under-eye masks since the OM itself is reported to contain diffusible small compounds with proven skincare benefits. OM from blended fresh okra pods without seeds was precipitated with ethanol. Preliminary studies showed that hydrogel pads prepared with XG, CN, glycerol, and NaCl at 0.5, 0.5, 13, and 4 wt%, respectively, possess a suitable hardness while exhibit the highest adhesive strength among other formulations tested. When OM powder was added at 0.02, 0.05, 0.06, 0.1, 0.2, 0.4, or 0.6 wt%, the OM-hydrogels’ hardnesses substantially drop. Increases in hardnesses and adhesive strengths with increasing amounts of OM powder were observed. The upward trend of adhesive strengths continues only up to 0.2 wt% where the adhesive strength begins to drop. In OM-hydrogels containing 0.2 wt% OM powder, normalized rates of moisture loss are the lowest while water contents and water holding capacities are the highest.
{"title":"XANTHAN GUM/CARRAGEENAN-BASED HYDROGEL PADS WITH OKRA FRUIT MUCILAGE POWDER FOR COSMECEUTICAL AND MEDICAL APPLICATIONS","authors":"J. Chokboribal, Aksarapaksorn Vipavin, Aiyada Sirinjullapong, V. Suchaiya, Narongrit Lahpun","doi":"10.55766/sujst-2023-02-e01536","DOIUrl":"https://doi.org/10.55766/sujst-2023-02-e01536","url":null,"abstract":"The main component of mucilage found in the fruit of okra (Abelmoschus esculentus) is okra gum consisting of pectic polysaccharides reported to exhibit, inter alia, antibacterial and antioxidant characteristics. It was used in the pharmaceutical industry, e.g. as a stabilizer or a modifier drug release. In this work, various formulations of xanthan gum (XG)/κ-carrageenan (CN)-based hydrogel with okra mucilage (OM) powder were examined to achieve the goal of developing OM-hydrogel pads that make good use of the advantages of OM polysaccharides relevant to drug delivery and/or stability. A straightforward cosmeceutical application of the OM-hydrogels is as under-eye masks since the OM itself is reported to contain diffusible small compounds with proven skincare benefits. OM from blended fresh okra pods without seeds was precipitated with ethanol. Preliminary studies showed that hydrogel pads prepared with XG, CN, glycerol, and NaCl at 0.5, 0.5, 13, and 4 wt%, respectively, possess a suitable hardness while exhibit the highest adhesive strength among other formulations tested. When OM powder was added at 0.02, 0.05, 0.06, 0.1, 0.2, 0.4, or 0.6 wt%, the OM-hydrogels’ hardnesses substantially drop. Increases in hardnesses and adhesive strengths with increasing amounts of OM powder were observed. The upward trend of adhesive strengths continues only up to 0.2 wt% where the adhesive strength begins to drop. In OM-hydrogels containing 0.2 wt% OM powder, normalized rates of moisture loss are the lowest while water contents and water holding capacities are the highest.","PeriodicalId":43478,"journal":{"name":"Suranaree Journal of Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.2,"publicationDate":"2023-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84019441","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 : 2023-05-29DOI: 10.55766/sujst-2023-02-e01887
M. N. Sudin, N. Md Daud, Faiz Redza Ramli, Mohd Asri Yusuff
A void is a structural defect resulting from the 3D printing process. The presence of voids compromises the structural integrity of a 3D-printed component, resulting in a reduction in durability and functionality. Currently, the only technique used to correlate FDM process parameters with mechanical properties is tensile testing. Nonetheless, this method is time-consuming and expensive. Therefore, the purpose of this study is to determine the viability of employing an alternative method to establish this connection. This study examined the parameters of infill density, infill pattern, raster angle, and part shape. While pressurized gas release was used to evaluate the printed material based on bubble formation, the printed object was evaluated based on bubble formation. Subsequently, the qualitative relationship between these parameters, void formation, and mechanical properties was determined. According to the results of this study, the relationship between the studied parameters, the tensile test, and the mechanical properties of the FDM part was consistent with the relationship between the studied parameters and the formation of bubbles and voids. 3D-printed parts with the lowest possible bubble intensity when using a 100% infill density, a grid infill pattern, and a 45° raster angle. The shape of the component was found to have the least impact on the formation of the bubble. This study concluded that using a 100% infill density, grid infill pattern, and 45° raster angle results in the least amount of void formation, and that the effect of shape difference on void formation in 3D-printed parts is negligible. The results of this study could be used to predict the mechanical properties of a component as a function of void formation during the (Pressurised gas release) PGR test. In the future, imaging-based quantitative analysis of voids will be required to validate this finding.
{"title":"EFFECT OF PROCESS PARAMETERS ON VOID FORMATION IN FUSED DEPOSITION MODELLING (FDM) PART","authors":"M. N. Sudin, N. Md Daud, Faiz Redza Ramli, Mohd Asri Yusuff","doi":"10.55766/sujst-2023-02-e01887","DOIUrl":"https://doi.org/10.55766/sujst-2023-02-e01887","url":null,"abstract":"A void is a structural defect resulting from the 3D printing process. The presence of voids compromises the structural integrity of a 3D-printed component, resulting in a reduction in durability and functionality. Currently, the only technique used to correlate FDM process parameters with mechanical properties is tensile testing. Nonetheless, this method is time-consuming and expensive. Therefore, the purpose of this study is to determine the viability of employing an alternative method to establish this connection. This study examined the parameters of infill density, infill pattern, raster angle, and part shape. While pressurized gas release was used to evaluate the printed material based on bubble formation, the printed object was evaluated based on bubble formation. Subsequently, the qualitative relationship between these parameters, void formation, and mechanical properties was determined. According to the results of this study, the relationship between the studied parameters, the tensile test, and the mechanical properties of the FDM part was consistent with the relationship between the studied parameters and the formation of bubbles and voids. 3D-printed parts with the lowest possible bubble intensity when using a 100% infill density, a grid infill pattern, and a 45° raster angle. The shape of the component was found to have the least impact on the formation of the bubble. This study concluded that using a 100% infill density, grid infill pattern, and 45° raster angle results in the least amount of void formation, and that the effect of shape difference on void formation in 3D-printed parts is negligible. The results of this study could be used to predict the mechanical properties of a component as a function of void formation during the (Pressurised gas release) PGR test. In the future, imaging-based quantitative analysis of voids will be required to validate this finding.","PeriodicalId":43478,"journal":{"name":"Suranaree Journal of Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.2,"publicationDate":"2023-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79949583","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 : 2023-05-29DOI: 10.55766/sujst-2023-02-e02019
Chiraporn Auechalitanukul, P. Jornsanoh, R. McCuiston, Jinjutha Sooksamran, Sukrita Leecharoen, Chonnipa Withaisong
The use of consumer and industrial waste as supplementary cementitious materials is one solution to the development of sustainable Portland cement. This research studied the partial replacement of cement with a pozzolanic mixture of recycled soda-lime glass powder (GP) and waste calcium hydroxide (CH). The optimal weight ratio of CH and GP was selected from five ratios between 30/70 to 70/30 (CH/GP), using thermal gravimetric analysis and X-ray diffraction. It was found that CH deficient ratios contained residual glass powder, while CH rich ratios contained residual calcium hydroxide and had undesirable carbonation of the CH. The 60/40 pozzolan was selected due to the large amount of calcium silicate hydrate (C-S-H) gel that was formed, the absence of residual GP and a minimum of excess CH. Portland cement (PC) specimens with 20 to 40 wt.% replacement by the 60/40 pozzolan were characterized for porosity and compressive strength at aging times from 3 to 28 days. The PC with 20 to 40 wt.% pozzolan had slightly increased porosity due to an increased amount of unreacted water from the batch. The porosity decreased with increased aging time. The PC with 30 wt.% pozzolan had a compressive strength equal to the reference PC, but only after 7 days or longer of aging. This was likely due to the slower reaction rate of the pozzolan. The 60/40 CH/GP pozzolan appears to be a viable partial replacement for PC when used at 30 wt.%.
{"title":"CREATION OF A POZZOLANIC MATERIAL FROM WASTE CALCIUM HYDROXIDE AND RECYCLED GLASS POWDER","authors":"Chiraporn Auechalitanukul, P. Jornsanoh, R. McCuiston, Jinjutha Sooksamran, Sukrita Leecharoen, Chonnipa Withaisong","doi":"10.55766/sujst-2023-02-e02019","DOIUrl":"https://doi.org/10.55766/sujst-2023-02-e02019","url":null,"abstract":"The use of consumer and industrial waste as supplementary cementitious materials is one solution to the development of sustainable Portland cement. This research studied the partial replacement of cement with a pozzolanic mixture of recycled soda-lime glass powder (GP) and waste calcium hydroxide (CH). The optimal weight ratio of CH and GP was selected from five ratios between 30/70 to 70/30 (CH/GP), using thermal gravimetric analysis and X-ray diffraction. It was found that CH deficient ratios contained residual glass powder, while CH rich ratios contained residual calcium hydroxide and had undesirable carbonation of the CH. The 60/40 pozzolan was selected due to the large amount of calcium silicate hydrate (C-S-H) gel that was formed, the absence of residual GP and a minimum of excess CH. Portland cement (PC) specimens with 20 to 40 wt.% replacement by the 60/40 pozzolan were characterized for porosity and compressive strength at aging times from 3 to 28 days. The PC with 20 to 40 wt.% pozzolan had slightly increased porosity due to an increased amount of unreacted water from the batch. The porosity decreased with increased aging time. The PC with 30 wt.% pozzolan had a compressive strength equal to the reference PC, but only after 7 days or longer of aging. This was likely due to the slower reaction rate of the pozzolan. The 60/40 CH/GP pozzolan appears to be a viable partial replacement for PC when used at 30 wt.%.","PeriodicalId":43478,"journal":{"name":"Suranaree Journal of Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.2,"publicationDate":"2023-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85320134","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 : 2023-05-29DOI: 10.55766/sujst-2023-02-e02065
Shivangi S. Somvanshi, M. Kumari, S. Zubair, Gaurav G.
Towards the end of 2019, a novel contagious virus (COVID-19) came out of Wuhan, China and turned into a disastrous pandemic. Many countries were locked down; completely or partially. The ongoing pandemic not only affected our economies and routine life, but also the environment. This study was aimed to compare the air quality of the Indian subcontinent prior to and during the COVID-19 pandemic. In this regard, air quality parameters (ozone, nitrogen dioxide, sulfur dioxide, carbon monoxide, PM2.5 and PM10) and meteorological parameters (wind speed and relative humidity) were analysed. The data was obtained from 229 monitoring stations in India and satellite-based Aerosol Absorption Index (AAI) during the springs of 2019 and 2020. The result indicated a significant decline in the concentration mean, six air pollutants (i.e., PM2.5, PM10, NO2, SO2, O3 and CO) decreased by 36.27, 42.96, 44.62, 28.88, 18.35 and 20.51 %, respectively during April 2020 due to less to no industrial activities and vehicular emissions. The spatial variation of each parameter was simulated using the Inverse Distance Weighted (IDW) interpolation method. An Analytical Hierarchy Process (AHP) model was applied to generate the overall air quality severity zonation map of the country. The zonation map indicated that by adopting cleaner fuel and restriction on biomass burning in the rural and urban sectors can improve the ambient air quality.
{"title":"IMPACT OF COVID-19 PANDEMIC ON THE AIR QUALITY OF INDIA","authors":"Shivangi S. Somvanshi, M. Kumari, S. Zubair, Gaurav G.","doi":"10.55766/sujst-2023-02-e02065","DOIUrl":"https://doi.org/10.55766/sujst-2023-02-e02065","url":null,"abstract":"Towards the end of 2019, a novel contagious virus (COVID-19) came out of Wuhan, China and turned into a disastrous pandemic. Many countries were locked down; completely or partially. The ongoing pandemic not only affected our economies and routine life, but also the environment. This study was aimed to compare the air quality of the Indian subcontinent prior to and during the COVID-19 pandemic. In this regard, air quality parameters (ozone, nitrogen dioxide, sulfur dioxide, carbon monoxide, PM2.5 and PM10) and meteorological parameters (wind speed and relative humidity) were analysed. The data was obtained from 229 monitoring stations in India and satellite-based Aerosol Absorption Index (AAI) during the springs of 2019 and 2020. The result indicated a significant decline in the concentration mean, six air pollutants (i.e., PM2.5, PM10, NO2, SO2, O3 and CO) decreased by 36.27, 42.96, 44.62, 28.88, 18.35 and 20.51 %, respectively during April 2020 due to less to no industrial activities and vehicular emissions. The spatial variation of each parameter was simulated using the Inverse Distance Weighted (IDW) interpolation method. An Analytical Hierarchy Process (AHP) model was applied to generate the overall air quality severity zonation map of the country. The zonation map indicated that by adopting cleaner fuel and restriction on biomass burning in the rural and urban sectors can improve the ambient air quality.","PeriodicalId":43478,"journal":{"name":"Suranaree Journal of Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.2,"publicationDate":"2023-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82942454","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 : 2023-05-29DOI: 10.55766/sujst-2023-02-e02013
S. K. Dubey, D. Mandal
This paper presents, a pattern synthesis method based on Differential Evolutionary Algorithm. A cosec2 beam pattern has been generated from different concentric circular ring arrays of isotropic elements by finding the optimum set of elements amplitude and phase using the Differential Evolution algorithm. The shaped beam pattern (cosec2) is generated in three predefined azimuth planes (φ=0°, 5° and 10°) from a Concentric Circular Antenna Array (CCAA) having two rings, three rings, and four rings. The total number or isotropic elements are equal for array geometries. The optimum excitation for array geometries is also verified for a range of arbitrarily chosen azimuth planes. The obtained main beam is similar to the desired pattern with some minor variations in peak Side Lobe Level (peak SLL) and ripple. Dynamic range ratio (DRR) is improved by using 4-bit discrete Amplitudes and 5-bit discrete Phases. These discrete excitations also simplify the design complexity of the feed networks.
{"title":"COSECANT-SQUARED BEAM PATTERN SYNTHESIS OF CONCENTRIC CIRCULAR ANTENNA ARRAY IN A RANGE OF AZIMUTH PLANE USING EVOLUTIONARY ALGORITHM","authors":"S. K. Dubey, D. Mandal","doi":"10.55766/sujst-2023-02-e02013","DOIUrl":"https://doi.org/10.55766/sujst-2023-02-e02013","url":null,"abstract":"This paper presents, a pattern synthesis method based on Differential Evolutionary Algorithm. A cosec2 beam pattern has been generated from different concentric circular ring arrays of isotropic elements by finding the optimum set of elements amplitude and phase using the Differential Evolution algorithm. The shaped beam pattern (cosec2) is generated in three predefined azimuth planes (φ=0°, 5° and 10°) from a Concentric Circular Antenna Array (CCAA) having two rings, three rings, and four rings. The total number or isotropic elements are equal for array geometries. The optimum excitation for array geometries is also verified for a range of arbitrarily chosen azimuth planes. The obtained main beam is similar to the desired pattern with some minor variations in peak Side Lobe Level (peak SLL) and ripple. Dynamic range ratio (DRR) is improved by using 4-bit discrete Amplitudes and 5-bit discrete Phases. These discrete excitations also simplify the design complexity of the feed networks.","PeriodicalId":43478,"journal":{"name":"Suranaree Journal of Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.2,"publicationDate":"2023-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86521148","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 : 2023-05-29DOI: 10.55766/sujst-2023-02-e02066
I. W. Azelee, A. Aris, W. A. A. ABU BAKAR
The Iodine/potassium iodide (I2/KI) lixiviant chemical possesses efficient treatment capabilities for elemental mercury (Hg°) removal on carbon steel’s porous surface. However, the mercury removal process on the contaminated carbon steel was observed to cause iron (Fe) to leach on the material’s surface. The results showed that the addition of imidazole as the corrosion inhibitor reduces 78.9% of Fe leaching with only 55% of Hg° removal. Compared to the oxidants of sodium hypochlorite (NaOCl) and tert-Butyl hydroperoxide (TBHP), only peroxyacetic acid (PAA) possesses a positive influence on the I2/KI reaction. Interestingly, PAA oxidant does not only enhance the Hg° removal up to 99% and reduce 73% of the Fe leaching but also reduces half of the treatment time from 16 to 8 h. While in the addition of NaOCl and TBHP oxidants, the efficiency of the decontamination process was only obtained at 54% and 59% for Hg° removal with 28.4% and 35.8% of Fe leaching, respectively.
{"title":"CORROSION INHIBITOR AND OXIDANTS EFFECT ON IRON LEACHING FROM CARBON STEEL DURING MERCURY REMOVAL","authors":"I. W. Azelee, A. Aris, W. A. A. ABU BAKAR","doi":"10.55766/sujst-2023-02-e02066","DOIUrl":"https://doi.org/10.55766/sujst-2023-02-e02066","url":null,"abstract":"The Iodine/potassium iodide (I2/KI) lixiviant chemical possesses efficient treatment capabilities for elemental mercury (Hg°) removal on carbon steel’s porous surface. However, the mercury removal process on the contaminated carbon steel was observed to cause iron (Fe) to leach on the material’s surface. The results showed that the addition of imidazole as the corrosion inhibitor reduces 78.9% of Fe leaching with only 55% of Hg° removal. Compared to the oxidants of sodium hypochlorite (NaOCl) and tert-Butyl hydroperoxide (TBHP), only peroxyacetic acid (PAA) possesses a positive influence on the I2/KI reaction. Interestingly, PAA oxidant does not only enhance the Hg° removal up to 99% and reduce 73% of the Fe leaching but also reduces half of the treatment time from 16 to 8 h. While in the addition of NaOCl and TBHP oxidants, the efficiency of the decontamination process was only obtained at 54% and 59% for Hg° removal with 28.4% and 35.8% of Fe leaching, respectively. \u0000 ","PeriodicalId":43478,"journal":{"name":"Suranaree Journal of Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.2,"publicationDate":"2023-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76114740","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 : 2023-05-29DOI: 10.55766/sujst-2023-02-e02352
Patiwat Kongdang, Thanusak Tatu
Thalassemia screening tests include one tube (0.36% NaCl) osmotic fragility test (OFT), mean corpuscular volume (MCV), and mean corpuscular hemoglobin (MCH). Reliability of these parameters in stored EDTA blood is the important issue to be concerned. To address this issue, we analyzed the results of these thalassemia screening tests in 50 fresh and stored EDTA blood samples of collected in the Chiang Mai province of northern Thailand. These blood samples; 25 with MCV < 80 fl and 25 with MCV ≥ 80 fl, were stored at room temperature (RT) (approximately 30°C) and in cold (approximately 4°C). OFT, MCV, and MCH were tested in both groups of blood samples everyday for 7 days. It was found that falsely negative OFT results were seen after 1 day and 4 days of storage at RT and in cold, respectively. For MCV, acceptable values were obtained at 0 day and 2-3 days storage at RT and in cold, respectively. No change of MCH values was observed throughout 7-day storage at both RT and cold. It was concluded that when performing thalassemia screening tests in Thailand, fresh EDTA blood must be used for OFT test and MCV determination. However, although MCH seemed to be the most stable parameters, thalassemia screen cannot rely only on MCH value. Therefore, thalassemia screen using these three tests must be done within blood collection day if no cooling facility is available. This information would also be useful for countries in tropical region where ambient temperature is high.
{"title":"INFLUENCE OF FRESHNESS OF EDTA BLOOD ON RELIABILITY OF THALASSEMIA SCREENING TESTS","authors":"Patiwat Kongdang, Thanusak Tatu","doi":"10.55766/sujst-2023-02-e02352","DOIUrl":"https://doi.org/10.55766/sujst-2023-02-e02352","url":null,"abstract":"Thalassemia screening tests include one tube (0.36% NaCl) osmotic fragility test (OFT), mean corpuscular volume (MCV), and mean corpuscular hemoglobin (MCH). Reliability of these parameters in stored EDTA blood is the important issue to be concerned. To address this issue, we analyzed the results of these thalassemia screening tests in 50 fresh and stored EDTA blood samples of collected in the Chiang Mai province of northern Thailand. These blood samples; 25 with MCV < 80 fl and 25 with MCV ≥ 80 fl, were stored at room temperature (RT) (approximately 30°C) and in cold (approximately 4°C). OFT, MCV, and MCH were tested in both groups of blood samples everyday for 7 days. It was found that falsely negative OFT results were seen after 1 day and 4 days of storage at RT and in cold, respectively. For MCV, acceptable values were obtained at 0 day and 2-3 days storage at RT and in cold, respectively. No change of MCH values was observed throughout 7-day storage at both RT and cold. It was concluded that when performing thalassemia screening tests in Thailand, fresh EDTA blood must be used for OFT test and MCV determination. However, although MCH seemed to be the most stable parameters, thalassemia screen cannot rely only on MCH value. Therefore, thalassemia screen using these three tests must be done within blood collection day if no cooling facility is available. This information would also be useful for countries in tropical region where ambient temperature is high.","PeriodicalId":43478,"journal":{"name":"Suranaree Journal of Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135831932","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 : 2023-05-29DOI: 10.55766/sujst-2023-02-e02063
Mohammad Fakhratul Ridwan Zulkifli, W. M. N. Wan Nik, Siti Hajar Abdullah, S. Jusoh, S. Abdullah, Adi Hafizamri Ariffin
This study was coordinated to investigate the potential of tannin extracted from mangrove bark (Rhizophora apiculata sp.) as an antifouling agent. Using natural resources as antifouling agents is an environmentally friendly alternative in industrial applications. Extracted tannin was formulated in a readily available epoxy coating and then coated on the mild steel samples. The samples were immersed in seawater for 60 days in Chendering Port and Marang Jetty. A screening test was performed via the anti-biofilm assay method to characterise the antimicrobial abilities. The IC50 of zinc tannate extract against Bacillus Cereus and Salmonella sp was 2.6 mg/ml and 28.75 mg/ml, respectively. It was discovered that fouling attachment is more noticeable in Chendering Port due to the physical parameters of the surrounding waters. Furthermore, the percentage of the weight acquired at Chendering port is higher than at Marang jetty. Surface inspection using digital photographs and scanning electron microscopy (SEM) reveals a denser tubeworm and mollusc attachment on the substrate without TZn. Higher tannin concentration has resulted in greater antifouling potential. Overall, the findings implicate that TZn has great potential as an antifouling additive in commercial marine coating.
{"title":"ANTIFOULING STUDY OF ZINC TANNATE (TZn) FOR MILD STEEL IN TROPICAL SEAWATER","authors":"Mohammad Fakhratul Ridwan Zulkifli, W. M. N. Wan Nik, Siti Hajar Abdullah, S. Jusoh, S. Abdullah, Adi Hafizamri Ariffin","doi":"10.55766/sujst-2023-02-e02063","DOIUrl":"https://doi.org/10.55766/sujst-2023-02-e02063","url":null,"abstract":"This study was coordinated to investigate the potential of tannin extracted from mangrove bark (Rhizophora apiculata sp.) as an antifouling agent. Using natural resources as antifouling agents is an environmentally friendly alternative in industrial applications. Extracted tannin was formulated in a readily available epoxy coating and then coated on the mild steel samples. The samples were immersed in seawater for 60 days in Chendering Port and Marang Jetty. A screening test was performed via the anti-biofilm assay method to characterise the antimicrobial abilities. The IC50 of zinc tannate extract against Bacillus Cereus and Salmonella sp was 2.6 mg/ml and 28.75 mg/ml, respectively. It was discovered that fouling attachment is more noticeable in Chendering Port due to the physical parameters of the surrounding waters. Furthermore, the percentage of the weight acquired at Chendering port is higher than at Marang jetty. Surface inspection using digital photographs and scanning electron microscopy (SEM) reveals a denser tubeworm and mollusc attachment on the substrate without TZn. Higher tannin concentration has resulted in greater antifouling potential. Overall, the findings implicate that TZn has great potential as an antifouling additive in commercial marine coating.","PeriodicalId":43478,"journal":{"name":"Suranaree Journal of Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.2,"publicationDate":"2023-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85639876","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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