Pub Date : 2023-08-31DOI: 10.17576/jsm-2023-5208-14
Asnan Rinovian Asnan Rinovian, Muhamad Nasir Muhamad Nasir, Muhammad Ali Zulfikar Muhammad Ali Zulfikar, Swasmi Purwajanti, Nugraha Nugraha, Nurrahmi Handayani, I Gusti Agung Suradharmika, Fitri Dara Fitri Dara
MgO nanoparticles (MgO NPs) incorporated PVDF-HFP nanofibers have been synthesized using the electrospinning method to remove arsenic from polluted water. MgO nanoparticles were synthesized from seawater bitterns and used as magnesium precursors. The synthesized materials were characterized using various techniques, and their adsorption capacities were evaluated against arsenic under different conditions. The results showed that the maximum adsorption for As(V) adsorption was 41.47 mg g-1 for PVDF-HFP/MgO 30% (w/w), which equals 179.69 mg g-1 based on the weight of bare MgO NPs and achieved at pH 11, a contact time of 420 minutes, and an adsorbent weight of 0.0125 g. Incorporating MgO NPs into the nanofiber matrix can enhance its stability, further increase the adsorption capacity. This study demonstrates the potential of using PVDF-HFP/MgO nanofiber composites to treat arsenic-containing wastewater and further provide commercial benefits for seawater bitterns by serving as a precursor for producing functional nanomaterials.
{"title":"Enhancing Arsenate Removal Efficiency Using Sewater Bittern-Derived MgO Nanoparticles/PVDF-HFP Electrospun Nanofibre Composites","authors":"Asnan Rinovian Asnan Rinovian, Muhamad Nasir Muhamad Nasir, Muhammad Ali Zulfikar Muhammad Ali Zulfikar, Swasmi Purwajanti, Nugraha Nugraha, Nurrahmi Handayani, I Gusti Agung Suradharmika, Fitri Dara Fitri Dara","doi":"10.17576/jsm-2023-5208-14","DOIUrl":"https://doi.org/10.17576/jsm-2023-5208-14","url":null,"abstract":"MgO nanoparticles (MgO NPs) incorporated PVDF-HFP nanofibers have been synthesized using the electrospinning method to remove arsenic from polluted water. MgO nanoparticles were synthesized from seawater bitterns and used as magnesium precursors. The synthesized materials were characterized using various techniques, and their adsorption capacities were evaluated against arsenic under different conditions. The results showed that the maximum adsorption for As(V) adsorption was 41.47 mg g-1 for PVDF-HFP/MgO 30% (w/w), which equals 179.69 mg g-1 based on the weight of bare MgO NPs and achieved at pH 11, a contact time of 420 minutes, and an adsorbent weight of 0.0125 g. Incorporating MgO NPs into the nanofiber matrix can enhance its stability, further increase the adsorption capacity. This study demonstrates the potential of using PVDF-HFP/MgO nanofiber composites to treat arsenic-containing wastewater and further provide commercial benefits for seawater bitterns by serving as a precursor for producing functional nanomaterials.","PeriodicalId":21366,"journal":{"name":"Sains Malaysiana","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136036186","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-31DOI: 10.17576/jsm-2023-5208-19
Sharifah Sakinah Syed Abd Mutalib, Siti Zanariah Satari, Wan Nur Syahidah Wan Yusoff
Outliers are abnormal data, and the detection of outliers in multivariate data has always been of interest. Unlike univariate data, outlier detection for multivariate data is insufficient with a visual inspection. In this study, we developed a new single linkage robust clustering outlier detection procedure for multivariate data. A robust estimator, Test on Covariance (TOC) is used to robustified the similarity distance measure, producing robust single linkage clustering. The performance of the new single linkage robust clustering outlier detection procedure is investigated via a simulation study using three outlier scenarios and historical multivariate datasets as illustrative examples. Three performance measures are used, which are pout, pmask, and pswamp. The performance of the new single linkage robust clustering procedure also compared with single linkage clustering using Euclidean and Mahalanobis distances as similarity distance measures as well as TOC. It is found that the new single linkage robust clustering procedure performs well in Outlier Scenario 3 when the mean and covariance matrix are shifted. The new procedure also performs well by successfully detecting all outliers, does not have masking effects in two out of five datasets and does not have swamping effect in all datasets. In conclusion, the new single linkage robust clustering outlier detection procedure is a practical and promising approach and good for simultaneously identifying multiple outliers in multivariate data.
异常值是异常数据，多变量数据中异常值的检测一直是人们感兴趣的问题。与单变量数据不同，单变量数据的异常值检测是不够的。在这项研究中，我们开发了一种新的单链接鲁棒聚类异常值检测程序，用于多变量数据。采用协方差检验(Test on Covariance, TOC)鲁棒估计方法对相似性距离测度进行鲁棒化，产生鲁棒的单链接聚类。通过对三种异常点场景和历史多元数据集的仿真研究，研究了新的单链接鲁棒聚类异常点检测方法的性能。使用了三种性能度量，分别是pout、pmask和pswamp。并将该方法与欧几里得距离和马氏距离作为相似距离度量以及TOC的单连杆鲁棒聚类方法进行了比较。结果表明，当均值和协方差矩阵发生移位时，新的单链接鲁棒聚类方法在Outlier场景3中表现良好。新方法还通过成功检测所有异常值而表现良好，在五个数据集中的两个数据集中没有屏蔽效应，并且在所有数据集中都没有淹没效应。总之，新的单链接鲁棒聚类异常点检测方法是一种实用且有前途的方法，可以同时识别多变量数据中的多个异常点。
{"title":"A New Single Linkage Robust Clustering Outlier Detection Procedures for Multivarite Data","authors":"Sharifah Sakinah Syed Abd Mutalib, Siti Zanariah Satari, Wan Nur Syahidah Wan Yusoff","doi":"10.17576/jsm-2023-5208-19","DOIUrl":"https://doi.org/10.17576/jsm-2023-5208-19","url":null,"abstract":"Outliers are abnormal data, and the detection of outliers in multivariate data has always been of interest. Unlike univariate data, outlier detection for multivariate data is insufficient with a visual inspection. In this study, we developed a new single linkage robust clustering outlier detection procedure for multivariate data. A robust estimator, Test on Covariance (TOC) is used to robustified the similarity distance measure, producing robust single linkage clustering. The performance of the new single linkage robust clustering outlier detection procedure is investigated via a simulation study using three outlier scenarios and historical multivariate datasets as illustrative examples. Three performance measures are used, which are pout, pmask, and pswamp. The performance of the new single linkage robust clustering procedure also compared with single linkage clustering using Euclidean and Mahalanobis distances as similarity distance measures as well as TOC. It is found that the new single linkage robust clustering procedure performs well in Outlier Scenario 3 when the mean and covariance matrix are shifted. The new procedure also performs well by successfully detecting all outliers, does not have masking effects in two out of five datasets and does not have swamping effect in all datasets. In conclusion, the new single linkage robust clustering outlier detection procedure is a practical and promising approach and good for simultaneously identifying multiple outliers in multivariate data.","PeriodicalId":21366,"journal":{"name":"Sains Malaysiana","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136036592","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-31DOI: 10.17576/jsm-2023-5208-06
Mohammed Yousaf Mohammed Yousaf, Ah Choo Koo, Mohd Hafizuddin Mohd Hafizuddin
The advent of social media technologies, specifically the phenomenal growth of online and interactive advertising, has assisted various organizations in responding to and communicating with respective consumers at sustainable expenditures through various online channels, including social media, with immense potential and popularity levels. Limited studies have been conducted to examine the connection between consumer engagements by small and medium enterprises (SMEs) and their respective promotional performances, as consumer purchase intention would be notably affected by the ability of an enterprise to interact and share information. Therefore, the current study aims to evaluate the impacts of attitude, brand loyalty, brand image, and brand awareness on interactive advertising and engagement with consumers via social media in the United Arab Emirates (UAE) to promote SME digital lifestyle products. Accordingly, a quantitative survey was administered to evaluate 308 responses from customers of companies vending digital lifestyle products before conducting partial least square structural equation modeling (PLS-SEM) to analyze the collected data. The results demonstrated significant positive relationships between both brand loyalty and brand awareness and consumer purchase intention, respectively, whereas the relationships between attitude and brand image and consumer purchase intention were separately discovered to be insignificant.
{"title":"Social Media Interactive Advertising and Purchase Intention of the UAE Customers: An Empirical Analysis","authors":"Mohammed Yousaf Mohammed Yousaf, Ah Choo Koo, Mohd Hafizuddin Mohd Hafizuddin","doi":"10.17576/jsm-2023-5208-06","DOIUrl":"https://doi.org/10.17576/jsm-2023-5208-06","url":null,"abstract":"The advent of social media technologies, specifically the phenomenal growth of online and interactive advertising, has assisted various organizations in responding to and communicating with respective consumers at sustainable expenditures through various online channels, including social media, with immense potential and popularity levels. Limited studies have been conducted to examine the connection between consumer engagements by small and medium enterprises (SMEs) and their respective promotional performances, as consumer purchase intention would be notably affected by the ability of an enterprise to interact and share information. Therefore, the current study aims to evaluate the impacts of attitude, brand loyalty, brand image, and brand awareness on interactive advertising and engagement with consumers via social media in the United Arab Emirates (UAE) to promote SME digital lifestyle products. Accordingly, a quantitative survey was administered to evaluate 308 responses from customers of companies vending digital lifestyle products before conducting partial least square structural equation modeling (PLS-SEM) to analyze the collected data. The results demonstrated significant positive relationships between both brand loyalty and brand awareness and consumer purchase intention, respectively, whereas the relationships between attitude and brand image and consumer purchase intention were separately discovered to be insignificant.","PeriodicalId":21366,"journal":{"name":"Sains Malaysiana","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136036593","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-31DOI: 10.17576/jsm-2023-5208-09
Idris Adewale Ahmed, Fasihuddin Badruddin Ahmad, Gwendoline Cheng Lian Ee, Siau Hui Mah, Nor hisam Zamakshshari
Cancer and antimicrobial resistance have become a threat to global health and development. This work aimed to identify the biological activities and phenolic compounds content of different Morinda citrifoliaL. root extracts. The relationship between biological activities and phenolic content was also discussed. All extracts were screened for antioxidant activity using anti-oxidant assays (FRAP, DPPH, TAOC, ABTS, and BCB) and quantitative phytochemical analyses (TPC). Antimicrobial activity against four bacterial and two fungal strains as well as cytotoxic activities on stomach cancer (SNU-1), colon cancer (LS-174T and HT29), leukemia (K562), and breast cancer (MDA-MB-361) cell lines were also performed. With a value of 122.789 g of gallic acid equivalent/mg extract, the dichloromethane extract had the highest total phenolic content (TPC). The extract also showed high antioxidant activities in all the antioxidant assays and antimicrobial activity. The FRAP (r2 = 0.962) as well as antimicrobial activities against Staphylococcus aureus (r2 = 0.708), Bacillus subtilis (r2 = 0.890) and Pseudomonas aeruginosa (r2 = 0.870) were strongly correlated with the total phenolic content. The LS-174T, K562, HT-29, and MDA-MB-361 cytotoxic activities were also strongly correlated with the total phenolic content with r2 = -0.899, -0.845, -0.981, and -0.978, respectively. The results obtained suggested that the dichloromethane extract of Morinda citrifolia has high biological activity compared to other extracts.
{"title":"Solvent Effect on the Phenolic Compounds and Biological Activity of Difference Morinda Citrifolia Root Extract","authors":"Idris Adewale Ahmed, Fasihuddin Badruddin Ahmad, Gwendoline Cheng Lian Ee, Siau Hui Mah, Nor hisam Zamakshshari","doi":"10.17576/jsm-2023-5208-09","DOIUrl":"https://doi.org/10.17576/jsm-2023-5208-09","url":null,"abstract":"Cancer and antimicrobial resistance have become a threat to global health and development. This work aimed to identify the biological activities and phenolic compounds content of different Morinda citrifoliaL. root extracts. The relationship between biological activities and phenolic content was also discussed. All extracts were screened for antioxidant activity using anti-oxidant assays (FRAP, DPPH, TAOC, ABTS, and BCB) and quantitative phytochemical analyses (TPC). Antimicrobial activity against four bacterial and two fungal strains as well as cytotoxic activities on stomach cancer (SNU-1), colon cancer (LS-174T and HT29), leukemia (K562), and breast cancer (MDA-MB-361) cell lines were also performed. With a value of 122.789 g of gallic acid equivalent/mg extract, the dichloromethane extract had the highest total phenolic content (TPC). The extract also showed high antioxidant activities in all the antioxidant assays and antimicrobial activity. The FRAP (r2 = 0.962) as well as antimicrobial activities against Staphylococcus aureus (r2 = 0.708), Bacillus subtilis (r2 = 0.890) and Pseudomonas aeruginosa (r2 = 0.870) were strongly correlated with the total phenolic content. The LS-174T, K562, HT-29, and MDA-MB-361 cytotoxic activities were also strongly correlated with the total phenolic content with r2 = -0.899, -0.845, -0.981, and -0.978, respectively. The results obtained suggested that the dichloromethane extract of Morinda citrifolia has high biological activity compared to other extracts.","PeriodicalId":21366,"journal":{"name":"Sains Malaysiana","volume":"69 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136036594","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-31DOI: 10.17576/jsm-2023-5208-11
Nurul Shazana Abdul Hamid, Raja Adibah Raja Halim, Idahwati Sarudin, Akimasa Yoshikawa, Akiko Fujimoto
This study investigated the simultaneous effects of solar flares (SFs) on both the D and E layers of Earth's ionosphere. The analysis focused on the M and X-class SFs that occurred during the 24th solar cycle as these two classes of SFs are known to produce significant effects on Earth’s environment, particularly during the daytime period. The data utilized to detect the SF events in this study were ground-based magnetometer data from the equatorial regions. Effects of the selected SF events on the E layer were investigated based on the EUEL index constructed using the geomagnetic data. Meanwhile, the changes in the strength of radio VLF signals in the D ionospheric layer during the selected SF events were monitored using Sudden Ionospheric Disturbance (SID) data. Two case studies were performed which consisted of four SF events from a total of 23 events that were detected by geomagnetic data during the period of study. Further analysis on the selected SF events showed the common effects of SFs on the D layer, which is the increment on the VLF signal measured from the SID stations although a different response was detected in the EUEL index variations. This indicates that the VLF signal always shows an increment even though a decrement in the ionization of the E layer occurs as a result of the SF events. The difference in responses could be attributed to the distinct changes in electron density of both layers during the SF occurrence. Further studies are needed to elucidate the underlying mechanism responsible for this unique response, utilizing appropriate parameters such as total electron content, as well as the electron density data to thoroughly analyze the ionospheric response during SF events.
{"title":"Examining Solar Flare Effects on Earth's Ionosphere Using Ground-Based Measurements","authors":"Nurul Shazana Abdul Hamid, Raja Adibah Raja Halim, Idahwati Sarudin, Akimasa Yoshikawa, Akiko Fujimoto","doi":"10.17576/jsm-2023-5208-11","DOIUrl":"https://doi.org/10.17576/jsm-2023-5208-11","url":null,"abstract":"This study investigated the simultaneous effects of solar flares (SFs) on both the D and E layers of Earth's ionosphere. The analysis focused on the M and X-class SFs that occurred during the 24th solar cycle as these two classes of SFs are known to produce significant effects on Earth’s environment, particularly during the daytime period. The data utilized to detect the SF events in this study were ground-based magnetometer data from the equatorial regions. Effects of the selected SF events on the E layer were investigated based on the EUEL index constructed using the geomagnetic data. Meanwhile, the changes in the strength of radio VLF signals in the D ionospheric layer during the selected SF events were monitored using Sudden Ionospheric Disturbance (SID) data. Two case studies were performed which consisted of four SF events from a total of 23 events that were detected by geomagnetic data during the period of study. Further analysis on the selected SF events showed the common effects of SFs on the D layer, which is the increment on the VLF signal measured from the SID stations although a different response was detected in the EUEL index variations. This indicates that the VLF signal always shows an increment even though a decrement in the ionization of the E layer occurs as a result of the SF events. The difference in responses could be attributed to the distinct changes in electron density of both layers during the SF occurrence. Further studies are needed to elucidate the underlying mechanism responsible for this unique response, utilizing appropriate parameters such as total electron content, as well as the electron density data to thoroughly analyze the ionospheric response during SF events.","PeriodicalId":21366,"journal":{"name":"Sains Malaysiana","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136036599","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-31DOI: 10.17576/jsm-2023-5208-17
Mustafid Amna Rambey, Siti Nurul Falaein Moridon, Khuzaimah Arifin, Lorna Jeffery Minggu, Mohammad B. Kassim
TiO2 nanotubes (NT) offer several advantages over other geometries for photoelectrochemical (PEC) applications. However, their performance in PEC water-splitting application has remained unsatisfactory due to its wide bandgap. To address this limitation, one approach is the incorporation of other materials as co-catalysts. Hence, in this study, a composite of TiO2 NT and cobalt sulfide (CoxSy) was successfully synthesized, and its potential as a photoelectrode for water molecules splitting was evaluated. The TiO2 NT was synthesized using electrochemical anodization of Ti foil, followed by annealing at 500 °C. Subsequently, CoxSy was added to the TiO2 NT using hydrothermal method, and the composite was further annealed at 400 °C. Characterization technique, such as FESEM and XRD were employed to identify the morphological and phase structures, while UV-Vis reflectance spectroscopy was used for optical analysis. The efficiency of CoxSy deposited on to TiO2 NT were evaluated by measuring the photocurrent generation. Remarkably, the sample of 60_CoxSy/TiO2 NT exhibited photocurrent as high as 0.375 mA/cm2 which is over sixfold higher than the bare TiO2 NT. The results reported in this study were higher than those reported previously.
{"title":"Composite of Titanium Dioxide Nanotube and Cobalt Sulfide for Photoelectrochemical Application","authors":"Mustafid Amna Rambey, Siti Nurul Falaein Moridon, Khuzaimah Arifin, Lorna Jeffery Minggu, Mohammad B. Kassim","doi":"10.17576/jsm-2023-5208-17","DOIUrl":"https://doi.org/10.17576/jsm-2023-5208-17","url":null,"abstract":"TiO2 nanotubes (NT) offer several advantages over other geometries for photoelectrochemical (PEC) applications. However, their performance in PEC water-splitting application has remained unsatisfactory due to its wide bandgap. To address this limitation, one approach is the incorporation of other materials as co-catalysts. Hence, in this study, a composite of TiO2 NT and cobalt sulfide (CoxSy) was successfully synthesized, and its potential as a photoelectrode for water molecules splitting was evaluated. The TiO2 NT was synthesized using electrochemical anodization of Ti foil, followed by annealing at 500 °C. Subsequently, CoxSy was added to the TiO2 NT using hydrothermal method, and the composite was further annealed at 400 °C. Characterization technique, such as FESEM and XRD were employed to identify the morphological and phase structures, while UV-Vis reflectance spectroscopy was used for optical analysis. The efficiency of CoxSy deposited on to TiO2 NT were evaluated by measuring the photocurrent generation. Remarkably, the sample of 60_CoxSy/TiO2 NT exhibited photocurrent as high as 0.375 mA/cm2 which is over sixfold higher than the bare TiO2 NT. The results reported in this study were higher than those reported previously.","PeriodicalId":21366,"journal":{"name":"Sains Malaysiana","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136036196","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Lassa fever (LF) is endemic in West Africa and Nigeria in particular. Since 1969 when the disease was discovered, a seasonal outbreak is often reported in Nigeria. Many researchers have reported inconsistent or varying numbers of suspected, confirmed and death cases since 2012 to date. To enhance this reportage, and due to the high mortality rate associated with LF, it is pertinent to design a suitable and robust model that could predict or estimate the number of LF cases based on the onset data. To achieve these, we proposed a recursive prediction (RP) model that could do predictions with the onset data. The Pearson correlation coefficient (R) and R2 are applied to determine the performance analysis of the model. The RP model predicted 96.7% confirmed cases and 89.6% death cases for the first three months of 2022 based on the onset data. The model was also applied to predict COVID-19 death cases during the six weeks of the outbreak in India. The result showed a comparable prediction with the regression output for the COVID-19 death cases. This study demonstrated that the proposed model could be applied to perform prediction for any disease of unknown etiology during the onset of the disease outbreak without any treatment similar to the COVID-19 outbreak. The performance analysis of the RP showed that the model is useful to predict the increasing trend of an outbreak of a disease with unknown etiology without prior treatment experience and vaccines.
{"title":"Recursive Prediction Model: A Preliminary Application to Lassa Fever Outbreak in Nigeria","authors":"Friday Zinzendoff Okwonu, Nor Aishah Ahad, Hashibah Hamid, Olimjon Shukurovich Sharipov","doi":"10.17576/jsm-2023-5208-16","DOIUrl":"https://doi.org/10.17576/jsm-2023-5208-16","url":null,"abstract":"Lassa fever (LF) is endemic in West Africa and Nigeria in particular. Since 1969 when the disease was discovered, a seasonal outbreak is often reported in Nigeria. Many researchers have reported inconsistent or varying numbers of suspected, confirmed and death cases since 2012 to date. To enhance this reportage, and due to the high mortality rate associated with LF, it is pertinent to design a suitable and robust model that could predict or estimate the number of LF cases based on the onset data. To achieve these, we proposed a recursive prediction (RP) model that could do predictions with the onset data. The Pearson correlation coefficient (R) and R2 are applied to determine the performance analysis of the model. The RP model predicted 96.7% confirmed cases and 89.6% death cases for the first three months of 2022 based on the onset data. The model was also applied to predict COVID-19 death cases during the six weeks of the outbreak in India. The result showed a comparable prediction with the regression output for the COVID-19 death cases. This study demonstrated that the proposed model could be applied to perform prediction for any disease of unknown etiology during the onset of the disease outbreak without any treatment similar to the COVID-19 outbreak. The performance analysis of the RP showed that the model is useful to predict the increasing trend of an outbreak of a disease with unknown etiology without prior treatment experience and vaccines.","PeriodicalId":21366,"journal":{"name":"Sains Malaysiana","volume":"84 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136036189","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-31DOI: 10.17576/jsm-2023-5208-04
Nur Azlina Adris, Lorna Jeffery Minggu, Khuzaimah Arifin, Rozan Mohamad Yunus, Mohamad Azuwa Mohamed, Masliana Muslimin, Mohammad B. Kassim
Copper (Cu) metal nanoparticles were deposited onto FTO glass using the electrodeposition method. The precursor used was CuSO4×5H2O with Na2SO4 as the inorganic additive. The formation of Cu was characterized using field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD). This study investigated the impacts of the electrodeposition method (direct electrodeposition vs. pulse electrodeposition), voltages (‑0.4 V and ‑0.8 V), electrodeposition time (60s to 900s) and pulse cycles (50 cycles to 300 cycles), and FTO etching (fixed to 20s etching) towards the morphology and adhesion of Cu deposited. The grain size and thickness of Cu deposited vary with deposition time and pulse cycles. The voltage of -0.4 V successfully deposits shiny, metallic brown Cu onto FTO glass. Meanwhile, the voltage of -0.8 V gives powdery brown Cu on the surface. In addition, compared to direct electrodeposition (DD), pulse electrodeposition (PD) provides a more compact and homogeneous coverage of Cu onto FTO glass. The tape-test results also indicate that FTO etching by electrolysis reduction can improve the adhesion strength between deposited thin Cu film and the FTO glass. This work demonstrates a facile electrodeposition technique with substrate etching as an effective deposition of Cu metal with the potential for application in a wide range of fields.
{"title":"Copper Nanoparticles Coating on FTO with Improved Adhesion Using Direct and Pulse Electrodeposition Techniques from a Simple Copper Sulphate Solution","authors":"Nur Azlina Adris, Lorna Jeffery Minggu, Khuzaimah Arifin, Rozan Mohamad Yunus, Mohamad Azuwa Mohamed, Masliana Muslimin, Mohammad B. Kassim","doi":"10.17576/jsm-2023-5208-04","DOIUrl":"https://doi.org/10.17576/jsm-2023-5208-04","url":null,"abstract":"Copper (Cu) metal nanoparticles were deposited onto FTO glass using the electrodeposition method. The precursor used was CuSO4×5H2O with Na2SO4 as the inorganic additive. The formation of Cu was characterized using field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD). This study investigated the impacts of the electrodeposition method (direct electrodeposition vs. pulse electrodeposition), voltages (‑0.4 V and ‑0.8 V), electrodeposition time (60s to 900s) and pulse cycles (50 cycles to 300 cycles), and FTO etching (fixed to 20s etching) towards the morphology and adhesion of Cu deposited. The grain size and thickness of Cu deposited vary with deposition time and pulse cycles. The voltage of -0.4 V successfully deposits shiny, metallic brown Cu onto FTO glass. Meanwhile, the voltage of -0.8 V gives powdery brown Cu on the surface. In addition, compared to direct electrodeposition (DD), pulse electrodeposition (PD) provides a more compact and homogeneous coverage of Cu onto FTO glass. The tape-test results also indicate that FTO etching by electrolysis reduction can improve the adhesion strength between deposited thin Cu film and the FTO glass. This work demonstrates a facile electrodeposition technique with substrate etching as an effective deposition of Cu metal with the potential for application in a wide range of fields.","PeriodicalId":21366,"journal":{"name":"Sains Malaysiana","volume":"84 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136036598","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-31DOI: 10.17576/jsm-2023-5208-07
Hui Kianga Tan, Haslaniza Hashim
Stemona curtisii, atau pokok Galak Tua berpotensi dalam memberikan manfaat kesihatan, perubatan serta sebagai racun perosak. Matlamat kajian ini adalah untuk menentukan kesan kaedah pengeringan yang berbeza (ketuhar, ketuhar gelombang mikro dan sinaran matahari) terhadap ciri fizikokimia, kandungan fenol dan aktiviti antioksida daun S. curtisii. Pengeringan ketuhar dijalankan pada suhu 40°C, 50°C dan 60°C selama 4.5-7 jam. Pengeringan ketuhar gelombang mikro pula menggunakan kuasa output 540 W, 720 W dan 900 W selama 3-5 minit. Bagi pengeringan matahari, daun dikeringkan di bawah sinaran matahari pada julat suhu 25-37°C. Hasil kajian menunjukkan pengeringan ketuhar gelombang mikro merupakan kaedah yang paling berkesan untuk mengeringkan daun S. curtisii berbanding kaedah pengeringan yang lain. Pengeringan ketuhar gelombang mikro 900 W mendatangkan perubahan warna (ΔE) dan peningkatan nilai pH yang minimum secara signifikan (p<0.05) terhadap daun S. curtisii. Dapatan kajian telah menunjukkan pengeringan ketuhar gelombang mikro 900 W menghasilkan nilai jumlah kandungan fenol (TPC) dan nilai penurunan kuasa ferik (FRAP) tertinggi (p<0.05) pada daun S. curtisii. Pengeringan ketuhar gelombang mikro pada ketiga-tiga kuasa menunjukkan nilai DPPH dan ABTS yang lebih tinggi (p<0.05) daripada kaedah pengeringan yang lain. Kajian menunjukkan korelasi positif yang signifikan (p<0.05) antara kandungan fenol dengan aktiviti antioksida daun S. curtisii. Kesimpulannya, ketuhar gelombang mikro 900 W adalah paling sesuai untuk pengeringan daun S. curtisii dengan ia menghasilkan ciri fizikokimia, kandungan fenol dan aktiviti antioksida yang lebih baik berbanding kaedah pengeringan yang lain.
Stemona curtisii，即老加拉树，具有保健、医药和毒药的潜力。本研究旨在确定不同干燥方法（烘箱、微波和阳光）对 S. curtisii 叶子的理化特性、酚含量和抗氧化活性的影响。日光干燥在 40°C、50°C 和 60°C 温度下进行，时间为 4.5-7 小时。微波炉干燥也使用 540 瓦、720 瓦和 900 瓦的输出功率，时间为 3-5 分钟。在太阳能干燥过程中，叶片在 25-37°C 的温度范围内晒干。结果表明，与其他干燥方法相比，微波炉干燥是最有效的 S. curtisii 叶子干燥方法。900 瓦微波炉烘干可使 S. curtisii 叶子的褪色（ΔE）和 pH 值的增加达到最小值（p<0.05）。研究结果表明，900 W 微波干燥导致 S. curtisii 叶片的总酚含量（TPC）和还原铁强度（FRAP）值最高（p & lt;0.05）。与其他干燥方法相比，微波炉在所有三种功率下干燥的 DPPH 值和 ABTS 值都更高（p & lt;0.05）。研究表明，S. curtisii 叶子的酚含量和抗氧化活性之间存在明显的正相关性（p & lt;0.05）。总之，与其他干燥方法相比，900 W 微波功率最适合用于干燥 S. curtisii 叶片，它能产生更好的理化特性、酚含量和抗氧化活性。
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Pub Date : 2023-08-31DOI: 10.17576/jsm-2023-5208-05
Mahmudul Hasan Mahmudul Hasan, Anis Syahirah Mokhtar, Khairil Mahmud, Adam Mustafa Rosli, Hafizuddin Hamdan, Motmainna Mst., Muhammad Saiful Ahmad-Hamdani
The development of plant-based bioherbicides has gained the interest of researchers and acceptability from the farmers to control weeds in order to reduce their overdependence on chemical herbicides. Therefore, this research investigated the efficacy and soil activity of WeedLock, a new plant-based bioherbicide. In the efficacy study, WeedLock was applied at 672.75, 1345.50 (recommended dose), 2691.00 L ha-1 over the untreated (control) on weeds in mixed- culture (Ageratum conyzoides L., Eleusine indica (L.) Gaertn., and Cyperus iria L). For soil activity, Zea mays L. seedlings were grown in different soil textures, namely clay, sand, sandy clay loam, and peat soil and WeedLock was applied to each soil type at 1345.50 L ha-1 with a pipette as a soil drench method. After 21 days, the plants were harvested, including roots and the soil in trays that were previously sprayed with WeedLock, and the trays were further maintained for 1, 2, 4, 8, 12 and 16 weeks, respectively, before new seedlings were grown on the same soil. WeedLock at 1345.50 L ha-1 showed severe injury on weeds and produced 98.15% weed control efficacy compared to untreated (control). For soil activity, WeedLock did not show any significant decrease in growth and development of Z. mays, and the injury scale was 1.00, which means all leaves of Z. mays remained green, and the plants were actively growing on the WeedLock treated soils. Thus, it can be concluded that WeedLock has excellent weed control efficacy with soil activity.
植物基生物除草剂的开发已经引起了研究者的兴趣和农民的接受，以控制杂草，以减少他们对化学除草剂的过度依赖。因此，本研究对新型植物基生物除草剂WeedLock的药效和土壤活性进行了研究。在药效研究中，WeedLock分别以672.75、1345.50(推荐剂量)、2691.00 L ha-1(对照)的剂量施用于混合栽培杂草(Ageratum conyzoides L.、Eleusine indica (L.))。Gaertn。在土壤活性方面，将玉米幼苗生长在粘土、砂土、砂质粘土壤土和泥炭土等不同土壤质地中，并以1345.50 L ha-1的WeedLock为土壤滴灌剂。21天后，收获植株，包括之前喷洒了WeedLock的托盘中的根和土壤，托盘分别保持1、2、4、8、12和16周，然后在相同的土壤上生长新的幼苗。1345.50 L ha-1 WeedLock对杂草的伤害较重，防杂草效果为98.15%。在土壤活性方面，WeedLock对玉米的生长发育无显著影响，伤害尺度为1.00，表明玉米叶片全部保持绿色，植株在WeedLock处理的土壤上生长活跃。综上所述，WeedLock具有优异的防杂草效果和土壤活性。
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