T. Shams, Jamil Haider Chowdhury, H. Chowdhury, Q. Ahsan, Hrionmoy Dutta, M. Tareq, L. Shirin, S. Akhter, Tania Islam
Bangladesh has experienced a sharp rise in cases during the third wave of the COVID-19 pandemic. This study investigates chest computed tomography (CT) and clinical findings of COVID-19 patients in Bangladesh. It is a single-centred cross-sectional study conducted at Chittagong Ma O Shishu Hospital. In total, 242 COVID-19 patients were recruited between June 2020 and July 2021 from a tertiary hospital in Chittagong, Bangladesh—most patients had a fever (90%) and cough (74.7%). Only a few patients had dyspnoea (13.3%), body aches (3.6%), sore throat (0.4%), fatigue (0.8%), diarrhoea (1.2%), headache (2%), and anosmia (2%). Most (91.3%) patients had abnormal CT image findings. Findings revealed that 89.6% had bilateral lung patchy opacities, 84.3% had ground glass opacities and crazy paving appearance, 29.3% had consolidation, and 16.9% had traction bronchiectasis. Clinical features, i.e., fever (93.7%) and cough (78.3%), were significantly more common (P<0.05) among those with positive radiological findings compared to those with negative radiological findings. However, this found that patients with negative radiological findings were more likely to have body aches (4.8%) than those with positive radiological findings (P=0.012). Most patients had lung involvement. There was no statistically significant difference in the demographic and patient comorbidities between these two radiological groups. A Chest CT scan was the best radiological option for detecting the progression of COVID-19 in high-risk and low-risk groups to initiate early clinical management and prevent complications during the pandemic.
{"title":"Chest Computed Tomography (CT) and Clinical Findings Among COVID-19 Patients of Tertiary Hospital in Bangladesh","authors":"T. Shams, Jamil Haider Chowdhury, H. Chowdhury, Q. Ahsan, Hrionmoy Dutta, M. Tareq, L. Shirin, S. Akhter, Tania Islam","doi":"10.47836/pjst.31.5.05","DOIUrl":"https://doi.org/10.47836/pjst.31.5.05","url":null,"abstract":"Bangladesh has experienced a sharp rise in cases during the third wave of the COVID-19 pandemic. This study investigates chest computed tomography (CT) and clinical findings of COVID-19 patients in Bangladesh. It is a single-centred cross-sectional study conducted at Chittagong Ma O Shishu Hospital. In total, 242 COVID-19 patients were recruited between June 2020 and July 2021 from a tertiary hospital in Chittagong, Bangladesh—most patients had a fever (90%) and cough (74.7%). Only a few patients had dyspnoea (13.3%), body aches (3.6%), sore throat (0.4%), fatigue (0.8%), diarrhoea (1.2%), headache (2%), and anosmia (2%). Most (91.3%) patients had abnormal CT image findings. Findings revealed that 89.6% had bilateral lung patchy opacities, 84.3% had ground glass opacities and crazy paving appearance, 29.3% had consolidation, and 16.9% had traction bronchiectasis. Clinical features, i.e., fever (93.7%) and cough (78.3%), were significantly more common (P<0.05) among those with positive radiological findings compared to those with negative radiological findings. However, this found that patients with negative radiological findings were more likely to have body aches (4.8%) than those with positive radiological findings (P=0.012). Most patients had lung involvement. There was no statistically significant difference in the demographic and patient comorbidities between these two radiological groups. A Chest CT scan was the best radiological option for detecting the progression of COVID-19 in high-risk and low-risk groups to initiate early clinical management and prevent complications during the pandemic.","PeriodicalId":46234,"journal":{"name":"Pertanika Journal of Science and Technology","volume":"46 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2023-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84299002","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}
G. Linets, A. Bazhenov, S. Malygin, N. Grivennaya, Тatiana Сhernysheva, S. Melnikov
The study of soil agrophysical and agrochemical properties is based on ground-based point measurements and measurements conducted using radiometric remote sensing systems (satellite or airborne). A disadvantage of the existing remote sensing systems using normal surface irradiation is the insignificant depth of penetration of the probing radiation into the soil layer. It is proposed to use a radar system for remote sensing agricultural lands to eliminate this drawback. The system uses a method for assessing the soil’s physical and chemical properties based on the interference measurements of direct and reflected electromagnetic waves at incidence angles that provide a total refraction effect, i.e., close to Brewster’s angle. The possibility of using this method for remote assessment of soil’s physical and chemical properties, including the subsurface layer moisture, was established. A feature of the bistatic system is that it is necessary to coordinate the mutual arrangement of the transmitting and receiving positions, which imposes special requirements on the UAVs’ flight algorithm. The UAVs’ relative position makes it possible to form the conditions for the manifestation of the total refraction effect, to determine the current value of Brewster’s angle, and to fix these conditions for the subsequent flight, making it possible to measure the soil’s physical and chemical parameters. The research results can be used to implement precision farming technology in hard-to-reach places, large agricultural areas, and digital agriculture.
{"title":"Algorithm for the Joint Flight of Two Uncrewed Aerial Vehicles Constituting a Bistatic Radar System for the Soil Remote Sensing","authors":"G. Linets, A. Bazhenov, S. Malygin, N. Grivennaya, Тatiana Сhernysheva, S. Melnikov","doi":"10.47836/pjst.31.4.25","DOIUrl":"https://doi.org/10.47836/pjst.31.4.25","url":null,"abstract":"The study of soil agrophysical and agrochemical properties is based on ground-based point measurements and measurements conducted using radiometric remote sensing systems (satellite or airborne). A disadvantage of the existing remote sensing systems using normal surface irradiation is the insignificant depth of penetration of the probing radiation into the soil layer. It is proposed to use a radar system for remote sensing agricultural lands to eliminate this drawback. The system uses a method for assessing the soil’s physical and chemical properties based on the interference measurements of direct and reflected electromagnetic waves at incidence angles that provide a total refraction effect, i.e., close to Brewster’s angle. The possibility of using this method for remote assessment of soil’s physical and chemical properties, including the subsurface layer moisture, was established. A feature of the bistatic system is that it is necessary to coordinate the mutual arrangement of the transmitting and receiving positions, which imposes special requirements on the UAVs’ flight algorithm. The UAVs’ relative position makes it possible to form the conditions for the manifestation of the total refraction effect, to determine the current value of Brewster’s angle, and to fix these conditions for the subsequent flight, making it possible to measure the soil’s physical and chemical parameters. The research results can be used to implement precision farming technology in hard-to-reach places, large agricultural areas, and digital agriculture.","PeriodicalId":46234,"journal":{"name":"Pertanika Journal of Science and Technology","volume":"18 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2023-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79814356","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}
Researchers have worked on positive leader propagation models and proposed different theoretical and numerical approaches. The charge simulation method (CSM) has traditionally been chosen to model the quasi-static electric field of each stage of leader propagation. The biggest drawback of the CSM is that the calculation is complicated and time-consuming when dealing with asymmetric electric field structures. On the contrary, the finite element method (FEM) is more suitable and reliable for solving electrostatic field problems with asymmetric and complex boundary conditions, avoiding the difficulties of virtual charge configuration and electric field calculation under complex boundary conditions. This paper modeled a self-consistent streamer-leader propagation model in an inverted rod-plane air gap based on FEM and the voltage distortion method (VDM). The voltage distortion coefficient was analyzed to calculate the streamer length and space charge. The physical dynamic process of the discharge was simulated with the help of COMSOL Multiphysics and MATLAB co-simulation technology. The results show that the initial voltage of the first corona is -1036 kV, close to the experiment value of -1052 kV. The breakdown voltage of -1369 kV is highly consistent with the experimental value of -1365 kV. The largest streamer length is 2.72 m, slightly higher than the experimental value of 2.3 m. The leader velocity is 2.43×104 m/s, close to the experiment value of 2.2×104 m/s. This model has simple calculations and can be used in complex electrode configurations and arbitrary boundary conditions without simplifying the model structure, making the model more flexible.
{"title":"Self-Consistent Positive Streamer-Leader Propagation Model Based on Finite Element Method (FEM) and Voltage Distortion Method (VDM)","authors":"Ziwei Ma, J. Jasni, M. A. Ab. Kadir, N. Azis","doi":"10.47836/pjst.31.4.30","DOIUrl":"https://doi.org/10.47836/pjst.31.4.30","url":null,"abstract":"Researchers have worked on positive leader propagation models and proposed different theoretical and numerical approaches. The charge simulation method (CSM) has traditionally been chosen to model the quasi-static electric field of each stage of leader propagation. The biggest drawback of the CSM is that the calculation is complicated and time-consuming when dealing with asymmetric electric field structures. On the contrary, the finite element method (FEM) is more suitable and reliable for solving electrostatic field problems with asymmetric and complex boundary conditions, avoiding the difficulties of virtual charge configuration and electric field calculation under complex boundary conditions. This paper modeled a self-consistent streamer-leader propagation model in an inverted rod-plane air gap based on FEM and the voltage distortion method (VDM). The voltage distortion coefficient was analyzed to calculate the streamer length and space charge. The physical dynamic process of the discharge was simulated with the help of COMSOL Multiphysics and MATLAB co-simulation technology. The results show that the initial voltage of the first corona is -1036 kV, close to the experiment value of -1052 kV. The breakdown voltage of -1369 kV is highly consistent with the experimental value of -1365 kV. The largest streamer length is 2.72 m, slightly higher than the experimental value of 2.3 m. The leader velocity is 2.43×104 m/s, close to the experiment value of 2.2×104 m/s. This model has simple calculations and can be used in complex electrode configurations and arbitrary boundary conditions without simplifying the model structure, making the model more flexible.","PeriodicalId":46234,"journal":{"name":"Pertanika Journal of Science and Technology","volume":"489 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2023-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75137062","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}
Nor Faizatulfitri Binti Salleh, S. Yusup, P. C. Mandal, M. S. H. Ruslan
Due to the depleting production of conventional petroleum, heavy oil is turned to as an alternative. However, the presence of trace nickel and vanadium in heavy oil poses problems for the refining process in producing lighter-end products. Such problems are its tendency to poison the catalyst, accumulate during distillation, and corrode the equipment. The objective of this work is to remove the metal porphyrins from model oil using the thermally stable ionic liquid 1-butyl-3-methylimidazolium octylsulfate, [BMIM][OS] assisted by subcritical toluene (above boiling point, 110.6°C and below a critical point, 318.6°C at 41.264 bar) in a novel attempt. The experiments were conducted at 150ºC to 210ºC under a mixing time of 30 to 90 minutes while the pressure was monitored. Four metal porphyrins are used: nickel etioporphyrin, nickel tetraphenylporphyrin, vanadium oxide etioporphyrin, and vanadium oxide tetraphenylporphyrin. The results show that more than 40% of removal is achieved for all metal porphyrins, which shows great potential for further technological improvement. The Nuclear Magnetic Resonance (NMR) shows that the ionic liquid did not decompose at the process temperature, which proves great stability. The extraction of metal porphyrins follows the second-order extraction model with an R2 of more than 0.98.
{"title":"Extraction of Metalloporphyrins Using Subcritical Toluene-Assisted Thermally Stable Ionic Liquid","authors":"Nor Faizatulfitri Binti Salleh, S. Yusup, P. C. Mandal, M. S. H. Ruslan","doi":"10.47836/pjst.31.4.22","DOIUrl":"https://doi.org/10.47836/pjst.31.4.22","url":null,"abstract":"Due to the depleting production of conventional petroleum, heavy oil is turned to as an alternative. However, the presence of trace nickel and vanadium in heavy oil poses problems for the refining process in producing lighter-end products. Such problems are its tendency to poison the catalyst, accumulate during distillation, and corrode the equipment. The objective of this work is to remove the metal porphyrins from model oil using the thermally stable ionic liquid 1-butyl-3-methylimidazolium octylsulfate, [BMIM][OS] assisted by subcritical toluene (above boiling point, 110.6°C and below a critical point, 318.6°C at 41.264 bar) in a novel attempt. The experiments were conducted at 150ºC to 210ºC under a mixing time of 30 to 90 minutes while the pressure was monitored. Four metal porphyrins are used: nickel etioporphyrin, nickel tetraphenylporphyrin, vanadium oxide etioporphyrin, and vanadium oxide tetraphenylporphyrin. The results show that more than 40% of removal is achieved for all metal porphyrins, which shows great potential for further technological improvement. The Nuclear Magnetic Resonance (NMR) shows that the ionic liquid did not decompose at the process temperature, which proves great stability. The extraction of metal porphyrins follows the second-order extraction model with an R2 of more than 0.98.","PeriodicalId":46234,"journal":{"name":"Pertanika Journal of Science and Technology","volume":"12 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2023-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77535785","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}
Habiba Khdair Abdalsada, Hadi Hassan Hadi, Abbas F. Almulla, A. Najm, Ameer Al-Isa, H. Al-Hakeim
End-stage renal disease (ESRD) patients are prone to cardiovascular disease (CVD). The search for a biomarker that determines patients at great risk of CVD is still a hot topic of study. In the present study, stromelysin-1 and its inhibitor (TIMP1), in addition to atherogenic indices, were studied in ESRD patients. We assessed stromelysin-1, TIMP1, and lipid profile parameters in the serum of 60 ESRD patients and 30 healthy controls. A neural network study was conducted to determine the best factors for predicting ESRD patients more susceptible to developing CVD using the cut-off value of the atherogenic index of plasma (AIP) >0.24. ESRD patients have dyslipidemia, high atherogenic indices, and elevated levels of stromelysin-1 and TIMP1. There is a correlation between the rise in stromelysin-1 and its inhibitor and several atherogenic indices and lipids in those patients. The neural network results indicated that the area under the curve predicting CVD, using the measured eight parameters, was 0.833, with 80 % sensitivity and 100% specificity. The relative importance of the top four most effective input variables that represent the most important determinants for the prediction of high risk of CVD stromelysin-1 (100%), followed by eGFR (77.9%), TIMP1 (66.0%), and TIMP1/stromelysin-1 (30.7%). ESRD patients have dyslipidemia and are prone to CVD, and stromelysin-1 is the best parameter for predicting CVD in ESRD patients.
{"title":"Correlation of Stromelysin-1 and Tissue Inhibitor of Metalloproteinase-1 with Lipid Profile and Atherogenic Indices in End-Stage Renal Disease Patients: A Neural Network Study","authors":"Habiba Khdair Abdalsada, Hadi Hassan Hadi, Abbas F. Almulla, A. Najm, Ameer Al-Isa, H. Al-Hakeim","doi":"10.47836/pjst.31.4.27","DOIUrl":"https://doi.org/10.47836/pjst.31.4.27","url":null,"abstract":"End-stage renal disease (ESRD) patients are prone to cardiovascular disease (CVD). The search for a biomarker that determines patients at great risk of CVD is still a hot topic of study. In the present study, stromelysin-1 and its inhibitor (TIMP1), in addition to atherogenic indices, were studied in ESRD patients. We assessed stromelysin-1, TIMP1, and lipid profile parameters in the serum of 60 ESRD patients and 30 healthy controls. A neural network study was conducted to determine the best factors for predicting ESRD patients more susceptible to developing CVD using the cut-off value of the atherogenic index of plasma (AIP) >0.24. ESRD patients have dyslipidemia, high atherogenic indices, and elevated levels of stromelysin-1 and TIMP1. There is a correlation between the rise in stromelysin-1 and its inhibitor and several atherogenic indices and lipids in those patients. The neural network results indicated that the area under the curve predicting CVD, using the measured eight parameters, was 0.833, with 80 % sensitivity and 100% specificity. The relative importance of the top four most effective input variables that represent the most important determinants for the prediction of high risk of CVD stromelysin-1 (100%), followed by eGFR (77.9%), TIMP1 (66.0%), and TIMP1/stromelysin-1 (30.7%). ESRD patients have dyslipidemia and are prone to CVD, and stromelysin-1 is the best parameter for predicting CVD in ESRD patients.","PeriodicalId":46234,"journal":{"name":"Pertanika Journal of Science and Technology","volume":"7 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2023-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76273312","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. Nabayi, Christopher Boon Sung Teh, Ngai Paing Tan, Ali Kee Zuan Tan
Washed rice water (WRW) is often used as liquid plant fertilizer. However, there is no study on nutrient leaching of soils due to frequent WRW application. Therefore, a column study was undertaken to evaluate the rate of nutrient leaching losses, nutrient retention, and recovery of elements in leachates of three different soil textures irrigated with WRW. The treatments were 3 soil textures and 2 water types. The treatments were evaluated for 8 weeks, and the soils and leachates were measured biweekly. Factorial and repeated measurements in a completely randomized design were therefore employed. Higher cumulative leaching of the elements was found in sandy clay loam soil with 666.29, 378.13, 138.51, 50.82, 44.61, and 27.30 mg L-1 of K, P, Mg, Ca, NH4+-N, and NO3--N, respectively. Higher percentages of elements recovery in leachate were found in the sandy clay loam soil with a range of increase by 37.8–283.1% than the other two soil textures. In contrast, after 8 weeks of WRW application, the clay and silt loam soils had a range of increase in nutrient retention by 0.43–1358.5% than the sandy clay loam, with P and NO3--N being the highest and the lowest elements retained, respectively, for all soil textures. This study showed that frequent WRW disposal on sandy textured soils risks higher environmental contamination, mainly due to the soil’s lower water retention and nutrients, leading to nutrient leaching. Therefore, organic amendments should be added to sandy textured soils.
{"title":"Nutrient Leaching Losses from Continuous Application of Washed Rice Water on Three Contrasting Soil Textures","authors":"A. Nabayi, Christopher Boon Sung Teh, Ngai Paing Tan, Ali Kee Zuan Tan","doi":"10.47836/pjst.31.4.20","DOIUrl":"https://doi.org/10.47836/pjst.31.4.20","url":null,"abstract":"Washed rice water (WRW) is often used as liquid plant fertilizer. However, there is no study on nutrient leaching of soils due to frequent WRW application. Therefore, a column study was undertaken to evaluate the rate of nutrient leaching losses, nutrient retention, and recovery of elements in leachates of three different soil textures irrigated with WRW. The treatments were 3 soil textures and 2 water types. The treatments were evaluated for 8 weeks, and the soils and leachates were measured biweekly. Factorial and repeated measurements in a completely randomized design were therefore employed. Higher cumulative leaching of the elements was found in sandy clay loam soil with 666.29, 378.13, 138.51, 50.82, 44.61, and 27.30 mg L-1 of K, P, Mg, Ca, NH4+-N, and NO3--N, respectively. Higher percentages of elements recovery in leachate were found in the sandy clay loam soil with a range of increase by 37.8–283.1% than the other two soil textures. In contrast, after 8 weeks of WRW application, the clay and silt loam soils had a range of increase in nutrient retention by 0.43–1358.5% than the sandy clay loam, with P and NO3--N being the highest and the lowest elements retained, respectively, for all soil textures. This study showed that frequent WRW disposal on sandy textured soils risks higher environmental contamination, mainly due to the soil’s lower water retention and nutrients, leading to nutrient leaching. Therefore, organic amendments should be added to sandy textured soils.","PeriodicalId":46234,"journal":{"name":"Pertanika Journal of Science and Technology","volume":"255 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2023-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73122553","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}
Thanks to the growth in data storage capacity, nowadays, researchers can use years’ worth of mathematical models and depend on past datasets. A pattern of all pandemics can be identified through the assistance of Machine Learning. The movement of the COVID-19 herd and any future pandemic can be predicted. These predictions will vary based on the dataset, but it will allow the preparation beforehand and stop the spreading of COVID-19. This study focuses on developing Spatio-temporal models using Machine Learning to produce a predictive visualized heat regional map of COVID-19 worldwide. Different models of Machine Learning are compared using John Hopkins University dataset. This study has compared well-known basic models like Support Vector Machine (SVM), Prophet, Bayesian Ridge Regression, and Polynomial Regression. Based on the comparison of various metrics of the Support Vector Machine, Polynomial Regression Model was found to be better and hence can be assumed to give good results for long-term prediction. On the other hand, ARIMA, Prophet Model, and Bayesian Ridge Reduction models are good for short-term predictions. The metrics such as Mean Absolute Error (MAE), Mean Squared Error (MSE), and Root Mean Square Error (RMSE) are better for Support Vector Machines compared to other models. The metrics such as R2 Score and Adjusted R-Square are better for the polynomial Regression model.
{"title":"Forecasting Geo Location of COVID-19 Herd","authors":"Divyansh Agarwal, Nishita Patnaik, Aravind Harinarayanan, S. Senthilkumar, Brindha Krishnamurthy, Kathiravan Srinivasan","doi":"10.47836/pjst.31.4.23","DOIUrl":"https://doi.org/10.47836/pjst.31.4.23","url":null,"abstract":"Thanks to the growth in data storage capacity, nowadays, researchers can use years’ worth of mathematical models and depend on past datasets. A pattern of all pandemics can be identified through the assistance of Machine Learning. The movement of the COVID-19 herd and any future pandemic can be predicted. These predictions will vary based on the dataset, but it will allow the preparation beforehand and stop the spreading of COVID-19. This study focuses on developing Spatio-temporal models using Machine Learning to produce a predictive visualized heat regional map of COVID-19 worldwide. Different models of Machine Learning are compared using John Hopkins University dataset. This study has compared well-known basic models like Support Vector Machine (SVM), Prophet, Bayesian Ridge Regression, and Polynomial Regression. Based on the comparison of various metrics of the Support Vector Machine, Polynomial Regression Model was found to be better and hence can be assumed to give good results for long-term prediction. On the other hand, ARIMA, Prophet Model, and Bayesian Ridge Reduction models are good for short-term predictions. The metrics such as Mean Absolute Error (MAE), Mean Squared Error (MSE), and Root Mean Square Error (RMSE) are better for Support Vector Machines compared to other models. The metrics such as R2 Score and Adjusted R-Square are better for the polynomial Regression model.","PeriodicalId":46234,"journal":{"name":"Pertanika Journal of Science and Technology","volume":"52 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2023-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80378727","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}
Subathra Muniandy, M. I. Idris, Zul Atfyi Fauzan Mohammed Napiah, N. Norddin, Marzaini Rashid, A. W. Mahmood Zuhdi, Luke Bradley
Perovskite solar cell (PSC) technologies have recently become a popular research topic. The hole transport layers (HTL) are important in establishing stable and efficient PSC by regulating charge absorption, interlayer recombination losses, and band alignment. Spiro-OMeTAD was extensively used as the HTL to fabricate highly efficient PSCs. Despite Spiro-OMeTAD having the benefit of providing high PCEs, it is costly, hazardous to the ecology, and cannot provide high efficiencies in the lack of additional additives that can reduce their stabilities. Inorganic HTL, specifically nickel oxide (NiO), has garnered much interest due to its low-cost, enhanced mobility, and strong stability to attain high efficiency. This study investigated different precursor solutions of NiO synthesis (Method I, II, and III) and deposited using the spin coating approach. The films were annealed at different annealing temperatures (400°C, 550°C, and 700°C) and evaluated by X-ray powder diffraction (XRD), UV-Vis spectroscopy, and Scanning electron microscopy (SEM) to test their structural, morphological, and optical characteristics, respectively. The findings of XRD revealed that a higher annealing temperature increases the crystallite size and decreases the microstrain through the study from Scherrer’s and Williamson-Hall’s (WH) equations. From the SEM analysis, the films show uniformity, large crystals, and agglomeration of particles. The annealing temperature from 400°C to 700°C reduced bandgap energy from 3.6 eV to 2.1 eV. According to the result, NiO produced at an annealing temperature of 700°C (Method I) exhibited the best characteristics and might be a viable option for HTL in PSCs.
{"title":"The Effect of Different Precursor Solutions on the Structural, Morphological, and Optical Properties of Nickel Oxide as an Efficient Hole Transport Layer for Perovskite Solar Cells","authors":"Subathra Muniandy, M. I. Idris, Zul Atfyi Fauzan Mohammed Napiah, N. Norddin, Marzaini Rashid, A. W. Mahmood Zuhdi, Luke Bradley","doi":"10.47836/pjst.31.4.26","DOIUrl":"https://doi.org/10.47836/pjst.31.4.26","url":null,"abstract":"Perovskite solar cell (PSC) technologies have recently become a popular research topic. The hole transport layers (HTL) are important in establishing stable and efficient PSC by regulating charge absorption, interlayer recombination losses, and band alignment. Spiro-OMeTAD was extensively used as the HTL to fabricate highly efficient PSCs. Despite Spiro-OMeTAD having the benefit of providing high PCEs, it is costly, hazardous to the ecology, and cannot provide high efficiencies in the lack of additional additives that can reduce their stabilities. Inorganic HTL, specifically nickel oxide (NiO), has garnered much interest due to its low-cost, enhanced mobility, and strong stability to attain high efficiency. This study investigated different precursor solutions of NiO synthesis (Method I, II, and III) and deposited using the spin coating approach. The films were annealed at different annealing temperatures (400°C, 550°C, and 700°C) and evaluated by X-ray powder diffraction (XRD), UV-Vis spectroscopy, and Scanning electron microscopy (SEM) to test their structural, morphological, and optical characteristics, respectively. The findings of XRD revealed that a higher annealing temperature increases the crystallite size and decreases the microstrain through the study from Scherrer’s and Williamson-Hall’s (WH) equations. From the SEM analysis, the films show uniformity, large crystals, and agglomeration of particles. The annealing temperature from 400°C to 700°C reduced bandgap energy from 3.6 eV to 2.1 eV. According to the result, NiO produced at an annealing temperature of 700°C (Method I) exhibited the best characteristics and might be a viable option for HTL in PSCs.","PeriodicalId":46234,"journal":{"name":"Pertanika Journal of Science and Technology","volume":"22 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2023-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73209031","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}
Downscaling threatens the designers invested in integrity and error mitigation against soft errors. This study formulated the probability of soft error changing the logic state of a Differential Logic with an Inverter Latch (DIL). Using Cadence Virtuoso, current pulses were injected into various nodes in stages until a logic flip was instigated. The voltage and temperature parameters were increased to observe the current level changes over time. The critical charge from each stage was obtained, and a method to formulate the probability of each instance was developed. The voltage produced a higher effect of the change to the critical charge of any instance as compared to temperature. The findings revealed that the N-channel metal-oxide semiconductor (NMOS) drain is more vulnerable to temperature and voltage variation than P-channel metal-oxide semiconductor (PMOS).
{"title":"Probability Formulation of Soft Error in Memory Circuit","authors":"N. Julai, Farhana Mohamad, R. Sapawi, S. Suhaili","doi":"10.47836/pjst.31.4.19","DOIUrl":"https://doi.org/10.47836/pjst.31.4.19","url":null,"abstract":"Downscaling threatens the designers invested in integrity and error mitigation against soft errors. This study formulated the probability of soft error changing the logic state of a Differential Logic with an Inverter Latch (DIL). Using Cadence Virtuoso, current pulses were injected into various nodes in stages until a logic flip was instigated. The voltage and temperature parameters were increased to observe the current level changes over time. The critical charge from each stage was obtained, and a method to formulate the probability of each instance was developed. The voltage produced a higher effect of the change to the critical charge of any instance as compared to temperature. The findings revealed that the N-channel metal-oxide semiconductor (NMOS) drain is more vulnerable to temperature and voltage variation than P-channel metal-oxide semiconductor (PMOS).","PeriodicalId":46234,"journal":{"name":"Pertanika Journal of Science and Technology","volume":"15 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2023-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80695602","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Hussain, Peizhao Chen, Nagisa Koizumi, Baoxin Liu, Xiangdong Yan
Commonly, the columns and beams of glass panels are frequently subjected to in-plane loading, in which their joints will transfer the in-plane forces. Therefore, it is necessary to investigate the spring constants of the joints of these glass panels for the mechanical analysis of the structures. However, few issues were published on this subject, so estimating the spring constants of glass structure joints is important. Devote themselves to proposing methods to evaluate the spring constants of the joints of structural glass panels. This study tests two types of glass panels with thicknesses of 12 mm and 19 mm based on static and cycling loading. In addition, two types of Cushions: (1) aluminum and (2) rubber with a hardness of 65 and 90 degrees, are set between steel bolt(s) and glass panel(s) for the experiments. The spring constants are determined by the ratios of measured loads and the displacements between the glass panels and bolts. In addition, the authors proposed an equation to evaluate the bending spring constant from its axial spring constant determined by the loading tests. The experimental results showed that the joints with the aluminum cushion appear exactly non-linear elasticity while loading and unloading. Also, the pin junction within the central region (no Curve) is 0.6mm. It is also determined that aluminum (cushion) slides of approximately ±0.3mm under compression and tension. While loading (Tension/compression) is incremental, rubber acts nonlinearly but linear as unloaded.
{"title":"Experimental Study on Spring Constants of Structural Glass Panel Joints Under In-Plane Loading","authors":"S. Hussain, Peizhao Chen, Nagisa Koizumi, Baoxin Liu, Xiangdong Yan","doi":"10.47836/pjst.31.4.21","DOIUrl":"https://doi.org/10.47836/pjst.31.4.21","url":null,"abstract":"Commonly, the columns and beams of glass panels are frequently subjected to in-plane loading, in which their joints will transfer the in-plane forces. Therefore, it is necessary to investigate the spring constants of the joints of these glass panels for the mechanical analysis of the structures. However, few issues were published on this subject, so estimating the spring constants of glass structure joints is important. Devote themselves to proposing methods to evaluate the spring constants of the joints of structural glass panels. This study tests two types of glass panels with thicknesses of 12 mm and 19 mm based on static and cycling loading. In addition, two types of Cushions: (1) aluminum and (2) rubber with a hardness of 65 and 90 degrees, are set between steel bolt(s) and glass panel(s) for the experiments. The spring constants are determined by the ratios of measured loads and the displacements between the glass panels and bolts. In addition, the authors proposed an equation to evaluate the bending spring constant from its axial spring constant determined by the loading tests. The experimental results showed that the joints with the aluminum cushion appear exactly non-linear elasticity while loading and unloading. Also, the pin junction within the central region (no Curve) is 0.6mm. It is also determined that aluminum (cushion) slides of approximately ±0.3mm under compression and tension. While loading (Tension/compression) is incremental, rubber acts nonlinearly but linear as unloaded.","PeriodicalId":46234,"journal":{"name":"Pertanika Journal of Science and Technology","volume":"26 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2023-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83478496","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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