The presence of heavy metals in rivers in the Niger Delta region has become a source of concern due to its associated health challenges. The present study was conducted to assess the risk of heavy metal accumulation in surface sediments obtained from creeks and dredged tributaries of the River Ethiope, Delta State, South-South, Nigeria. Heavy metals in the sediments were extracted using the three-step sequential extraction method of the European Commission Standard Measurement and Testing Program. The heavy metals; magnesium (Mn), iron (Fe), zinc (Zn), lead (Pb), copper (Cu), cobalt (Co), arsenic (As), chromium (Cr), cadmium (Cd) and barium (Ba) were quantified by employing inductively coupled plasma-mass spectrometry (ICP-MS). Assessment of the extent of sediment contamination was carried out by determining the contamination factor (CF), degree of contamination (Cd), modified degree of contamination (mCd), pollution load index (PLI), ecological risk factor (Er), potential ecological risk index (PI) and geo accumulation index (1 geo). Pearson’s correlation coefficient and principal component analysis (PCA) were used to determine the sources and the relationship between pollutants across sediments. The values of heavy metals ranged from 12.5 mg kg–1–116 mg kg–1 and 21.6 mg kg–1–71.1 mg kg–1 in the wet and dry seasons, respectively. The trend of heavy metals for risk index (RI) in this study is Cd > Pb > Cr > Co > Zn > Cu > Mn (wet season) and Cu > Cd > Pb > Zn > Cr > Mn > Co = As (dry season). It showed that heavy metal pollution was a result of Cd for extreme contamination, while moderate to high contamination levels were due to Pb and Cu. The Pearson’s correlation coefficient analysis and PCA displayed strong positive loadings for Mn, Fe, Zn, Pb, Cu and Cd across seasons as a result of high contamination levels in the study sites. The pollution load index revealed that the sediments were polluted by the metals, and the mean and median analyses revealed that the metals datasets were normally distributed, except for Cu with an irregular distribution.
{"title":"Accumulation and Risk Assessment of Heavy Metals in Sediments from Dredged Tributaries and Creeks of River Ethiope, South-South, Nigeria","authors":"Eyenubo O.B., Ikpefan J.O., Peretomode V.O., E. F., Osakwe S.A., Avwioro O.G.","doi":"10.21315/jps2023.34.3.7","DOIUrl":"https://doi.org/10.21315/jps2023.34.3.7","url":null,"abstract":"The presence of heavy metals in rivers in the Niger Delta region has become a source of concern due to its associated health challenges. The present study was conducted to assess the risk of heavy metal accumulation in surface sediments obtained from creeks and dredged tributaries of the River Ethiope, Delta State, South-South, Nigeria. Heavy metals in the sediments were extracted using the three-step sequential extraction method of the European Commission Standard Measurement and Testing Program. The heavy metals; magnesium (Mn), iron (Fe), zinc (Zn), lead (Pb), copper (Cu), cobalt (Co), arsenic (As), chromium (Cr), cadmium (Cd) and barium (Ba) were quantified by employing inductively coupled plasma-mass spectrometry (ICP-MS). Assessment of the extent of sediment contamination was carried out by determining the contamination factor (CF), degree of contamination (Cd), modified degree of contamination (mCd), pollution load index (PLI), ecological risk factor (Er), potential ecological risk index (PI) and geo accumulation index (1 geo). Pearson’s correlation coefficient and principal component analysis (PCA) were used to determine the sources and the relationship between pollutants across sediments. The values of heavy metals ranged from 12.5 mg kg–1–116 mg kg–1 and 21.6 mg kg–1–71.1 mg kg–1 in the wet and dry seasons, respectively. The trend of heavy metals for risk index (RI) in this study is Cd > Pb > Cr > Co > Zn > Cu > Mn (wet season) and Cu > Cd > Pb > Zn > Cr > Mn > Co = As (dry season). It showed that heavy metal pollution was a result of Cd for extreme contamination, while moderate to high contamination levels were due to Pb and Cu. The Pearson’s correlation coefficient analysis and PCA displayed strong positive loadings for Mn, Fe, Zn, Pb, Cu and Cd across seasons as a result of high contamination levels in the study sites. The pollution load index revealed that the sediments were polluted by the metals, and the mean and median analyses revealed that the metals datasets were normally distributed, except for Cu with an irregular distribution.","PeriodicalId":16757,"journal":{"name":"Journal of Physical Science","volume":"34 17","pages":""},"PeriodicalIF":0.7,"publicationDate":"2023-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138984041","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}
Ivan Vasiliev, Sergey Saliy, Rollan Altynbekov, G. Rysbayeva, Vladimir Echin
The research delves into the significance of continuous emission radars of very high frequency (VHF) range in detecting small unmanned aircraft and marine targets for navigation safety. Recognising the need for improved radars and reduced coordinate measurement errors, the study aims to analyse discrepancies in azimuth and range determination in radars with fixed-phased antenna arrays. By developing effective tools with low computational complexity for target azimuth determination, the research seeks to enhance radar performance. Employing analytical, classification, functional, and statistical methods, the study comprehensively examines the peculiarities and differences of radars. It meticulously analyses coordinate measurement errors and investigates their causes. The impact of these discrepancies on radar performance and their relevance in various applications, particularly maritime navigation, is carefully evaluated. The findings emphasise the critical role of continuous emission radars in ensuring shipping safety and economic efficiency. The recommendations derived from the study offer valuable insights for improving radar effectiveness, addressing operational limitations, and enhancing overall functionality. By tackling coordinate measurement errors and providing accurate azimuth determination tools, this research contributes to advancing continuous emission radar technology and its practical applications. Through its findings and recommendations, the study aims to optimise radar performance, enhance navigation safety, and improve economic efficiency in diverse sectors.
{"title":"Issue of VHF Continuous Emission Radars Coordinate Measurement Discrepancy","authors":"Ivan Vasiliev, Sergey Saliy, Rollan Altynbekov, G. Rysbayeva, Vladimir Echin","doi":"10.21315/jps2023.34.3.3","DOIUrl":"https://doi.org/10.21315/jps2023.34.3.3","url":null,"abstract":"The research delves into the significance of continuous emission radars of very high frequency (VHF) range in detecting small unmanned aircraft and marine targets for navigation safety. Recognising the need for improved radars and reduced coordinate measurement errors, the study aims to analyse discrepancies in azimuth and range determination in radars with fixed-phased antenna arrays. By developing effective tools with low computational complexity for target azimuth determination, the research seeks to enhance radar performance. Employing analytical, classification, functional, and statistical methods, the study comprehensively examines the peculiarities and differences of radars. It meticulously analyses coordinate measurement errors and investigates their causes. The impact of these discrepancies on radar performance and their relevance in various applications, particularly maritime navigation, is carefully evaluated. The findings emphasise the critical role of continuous emission radars in ensuring shipping safety and economic efficiency. The recommendations derived from the study offer valuable insights for improving radar effectiveness, addressing operational limitations, and enhancing overall functionality. By tackling coordinate measurement errors and providing accurate azimuth determination tools, this research contributes to advancing continuous emission radar technology and its practical applications. Through its findings and recommendations, the study aims to optimise radar performance, enhance navigation safety, and improve economic efficiency in diverse sectors.","PeriodicalId":16757,"journal":{"name":"Journal of Physical Science","volume":"24 28","pages":""},"PeriodicalIF":0.7,"publicationDate":"2023-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138984199","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}
Anand Kumar Pandey, Raghvendra Pratap Singh, A. H. Jawhari, Ritu Singh
Single crystals of untreated and copper (Cu2+) metal ion-doped L-alanine aluminium nitrate (LAAN), a room-temperature slow evaporation organic nonlinear optical material. Single crystals were studied for structural, spectral, optical, hardness, secondorder non-linear optical, electrical [(alternating current (AC) and direct current (DC)], and photoconductivity properties as they grew. Crystallinity, monoclinic structure with space collection P21, and lattice specifications were deliberate using single crystal X-ray diffraction investigation. The existence of functional clusters is revealed by the spectral properties, and the means of vibration of various molecular clusters existing in LAAN were evaluated using Fourier transform infrared (FTIR). The low cut-off wavelength and transmittance properties were determined using optical analysis. The band gap energy of LAAN and Cu-doped LAAN crystals was estimated to be 3.40 eV and 2.70 eV, respectively, using the Tauc plot. It was revealed that pure crystals had a lower dielectric constant than crystals that had been doped with copper. After doping with rising temperatures, AC conductivity started to rise. With the use of the Kurtz and Perry approach, the effectiveness of the grown crystal’s second harmonic generation was computed, Cu-doped LAAN was discovered to be 3.3 times more prominent than potassium dihydrogen phosphate (KDP) and 2.2 times more prominent than pure LAAN crystals. The nonlinear optical characteristics of LAAN crystals have therefore been improved by copper doping. It is most suited for use in electro-optic applications like laser technology, telecommunications and optical signal processing because of its negative photoconductivity.
{"title":"Enhanced Characterisation Studies and Synthesis of Undoped and Copper Doped-Organic Nonlinear Optical Single Crystal: L-Alanine Aluminium Nitrate","authors":"Anand Kumar Pandey, Raghvendra Pratap Singh, A. H. Jawhari, Ritu Singh","doi":"10.21315/jps2023.34.3.8","DOIUrl":"https://doi.org/10.21315/jps2023.34.3.8","url":null,"abstract":"Single crystals of untreated and copper (Cu2+) metal ion-doped L-alanine aluminium nitrate (LAAN), a room-temperature slow evaporation organic nonlinear optical material. Single crystals were studied for structural, spectral, optical, hardness, secondorder non-linear optical, electrical [(alternating current (AC) and direct current (DC)], and photoconductivity properties as they grew. Crystallinity, monoclinic structure with space collection P21, and lattice specifications were deliberate using single crystal X-ray diffraction investigation. The existence of functional clusters is revealed by the spectral properties, and the means of vibration of various molecular clusters existing in LAAN were evaluated using Fourier transform infrared (FTIR). The low cut-off wavelength and transmittance properties were determined using optical analysis. The band gap energy of LAAN and Cu-doped LAAN crystals was estimated to be 3.40 eV and 2.70 eV, respectively, using the Tauc plot. It was revealed that pure crystals had a lower dielectric constant than crystals that had been doped with copper. After doping with rising temperatures, AC conductivity started to rise. With the use of the Kurtz and Perry approach, the effectiveness of the grown crystal’s second harmonic generation was computed, Cu-doped LAAN was discovered to be 3.3 times more prominent than potassium dihydrogen phosphate (KDP) and 2.2 times more prominent than pure LAAN crystals. The nonlinear optical characteristics of LAAN crystals have therefore been improved by copper doping. It is most suited for use in electro-optic applications like laser technology, telecommunications and optical signal processing because of its negative photoconductivity.","PeriodicalId":16757,"journal":{"name":"Journal of Physical Science","volume":"23 18","pages":""},"PeriodicalIF":0.7,"publicationDate":"2023-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138984216","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}
Cellulose was successfully extracted from wastepaper with a pre-treatment using sodium hydroxide (NaOH) and hydrochloric acid (HCl). The cellulose was then used to fabricate two types of hydrogels: cellulose/carboxymethyl cellulose (CMC)/polyvinyl alcohol (PVA) and cellulose/CMC/glycerol. Epichlorohydrin, an ECH solution was used as a cross-linker for the fabrication of both types of hydrogels. NaOH/urea/ultrapure water (NU) solutions were used to dissolve all the materials needed for the formation of hydrogels. The attenuated total reflectance-Fourier transform infrared (ATR-FTIR) showed the presence of hydroxyl group (O-H), hydrocarbon group (C-H) and carbonyl group (C=O) stretching. Scanning electron microscope (SEM) showed different porosities for both types of hydrogels, while the equilibrium swelling, swellingeq of cellulose/CMC/ PVA hydrogels were better compared to the cellulose/CMC/glycerol hydrogels. The highest swellingeq was found for the cellulose/CMC/PVA hydrogel (3/3/4 ratio), CCP334 with 6.33 g/g, while the lowest swellingeq (g/g) was obtained from the cellulose/CMC/ glycerol hydrogel (3/2/5 ratio), CCG325 with 1.49 g/g.
{"title":"Effects of Plasticiser on the Morphology and Swelling Properties of Cellulose-based Hydrogels Derived from Wastepaper","authors":"Bebe Norlita Mohamed, Suk-Fun Chin, M. E. Wasli","doi":"10.21315/jps2023.34.3.4","DOIUrl":"https://doi.org/10.21315/jps2023.34.3.4","url":null,"abstract":"Cellulose was successfully extracted from wastepaper with a pre-treatment using sodium hydroxide (NaOH) and hydrochloric acid (HCl). The cellulose was then used to fabricate two types of hydrogels: cellulose/carboxymethyl cellulose (CMC)/polyvinyl alcohol (PVA) and cellulose/CMC/glycerol. Epichlorohydrin, an ECH solution was used as a cross-linker for the fabrication of both types of hydrogels. NaOH/urea/ultrapure water (NU) solutions were used to dissolve all the materials needed for the formation of hydrogels. The attenuated total reflectance-Fourier transform infrared (ATR-FTIR) showed the presence of hydroxyl group (O-H), hydrocarbon group (C-H) and carbonyl group (C=O) stretching. Scanning electron microscope (SEM) showed different porosities for both types of hydrogels, while the equilibrium swelling, swellingeq of cellulose/CMC/ PVA hydrogels were better compared to the cellulose/CMC/glycerol hydrogels. The highest swellingeq was found for the cellulose/CMC/PVA hydrogel (3/3/4 ratio), CCP334 with 6.33 g/g, while the lowest swellingeq (g/g) was obtained from the cellulose/CMC/ glycerol hydrogel (3/2/5 ratio), CCG325 with 1.49 g/g.","PeriodicalId":16757,"journal":{"name":"Journal of Physical Science","volume":"25 21","pages":""},"PeriodicalIF":0.7,"publicationDate":"2023-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138984153","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}
Dounia Ousmane Ahmat, Z. Jawad, Vahid Khosravi, S. Yeap
This research aimed to examine how varying the acidity levels during the chemical oxidative polymerisation (COP) of aniline affects the colour, yield, morphology, and surface functionalities of polyaniline (PANI). In the COP method, aniline monomer was first dissolved in hydrochloric acid (HCl) medium; the solution was then drop added with ammonium persulfate to initiate the polymerisation process. To answer the research objective, the medium acidity was manipulated using different concentrations of HCl (i.e., 0 M, 0.01 M, 0.1 M, 1 M and 10 M). The as-synthesised PANIs were then purified and characterised for their physicochemical properties. The findings revealed that reducing the medium pH from 2.35 (in distilled water) to 0.80 (in 10 M HCl) resulted in a colour change from light brownish to dark green, indicating the formation of emeraldine PANI. Furthermore, it was observed that the amount of PANI yield is inversely related to the medium pH. A decrease in medium pH from 2.35 to 0.80 remarkably increased the PANI yield by 3.2 times. Regarding morphological structure, higher medium acidity produced PANI with well-defined globule shapes, while lower HCl concentrations resulted in a mixed morphology including globules, tubes, and plate-like structures. In addition, it was found that the diameter of globule-like PANI has increased from ~266.67 nm to ~508.33 nm, when the HCl concentration was changed from 0 M to 10 M. Apparently, increasing the acidity of the COP medium promotes enlargement of the PANI size. Despite that, there is not much change in the surface functional groups of the formed PANI. Overall, this study offers insights into manipulating PANI properties by adjusting the medium acidity during the COP process. While the impacts of medium acidity on yield, morphology, and functionalities of PANI were revealed, further investigation is required to evaluate the effect on electrical properties.
本研究旨在探讨苯胺化学氧化聚合（COP）过程中不同的酸度如何影响聚苯胺（PANI）的颜色、产率、形态和表面功能。在 COP 方法中，苯胺单体首先溶解在盐酸（HCl）介质中，然后滴加过硫酸铵以启动聚合过程。为实现研究目标，使用不同浓度的盐酸（即 0 M、0.01 M、0.1 M、1 M 和 10 M）来调节介质酸度。然后对合成的 PANIs 进行纯化，并对其理化性质进行表征。研究结果表明，将介质 pH 值从 2.35（蒸馏水）降低到 0.80（10 M HCl）后，颜色从浅棕色变为深绿色，表明形成了翡翠色 PANI。此外，还观察到 PANI 的产量与培养基的 pH 值成反比。培养基 pH 值从 2.35 降低到 0.80，PANI 产量显著增加了 3.2 倍。在形态结构方面，较高的培养基酸度产生的 PANI 具有清晰的球状形状，而较低的盐酸浓度则产生混合形态，包括球状、管状和板状结构。此外，还发现当盐酸浓度从 0 M 变为 10 M 时，球状 PANI 的直径从 ~266.67 nm 增大到 ~508.33 nm。显然，增加 COP 培养基的酸度会促进 PANI 尺寸的增大。尽管如此，所形成的 PANI 的表面官能团变化不大。总之，这项研究为在 COP 过程中通过调整介质酸度来操纵 PANI 性能提供了启示。虽然研究揭示了介质酸度对 PANI 产量、形态和功能的影响，但还需要进一步研究以评估其对电性能的影响。
{"title":"Acidity’s Impact on Yield, Morphological Structure, and Surface Functionalities of Polyaniline Synthesised via Oxidative Polymerisation","authors":"Dounia Ousmane Ahmat, Z. Jawad, Vahid Khosravi, S. Yeap","doi":"10.21315/jps2023.34.3.5","DOIUrl":"https://doi.org/10.21315/jps2023.34.3.5","url":null,"abstract":"This research aimed to examine how varying the acidity levels during the chemical oxidative polymerisation (COP) of aniline affects the colour, yield, morphology, and surface functionalities of polyaniline (PANI). In the COP method, aniline monomer was first dissolved in hydrochloric acid (HCl) medium; the solution was then drop added with ammonium persulfate to initiate the polymerisation process. To answer the research objective, the medium acidity was manipulated using different concentrations of HCl (i.e., 0 M, 0.01 M, 0.1 M, 1 M and 10 M). The as-synthesised PANIs were then purified and characterised for their physicochemical properties. The findings revealed that reducing the medium pH from 2.35 (in distilled water) to 0.80 (in 10 M HCl) resulted in a colour change from light brownish to dark green, indicating the formation of emeraldine PANI. Furthermore, it was observed that the amount of PANI yield is inversely related to the medium pH. A decrease in medium pH from 2.35 to 0.80 remarkably increased the PANI yield by 3.2 times. Regarding morphological structure, higher medium acidity produced PANI with well-defined globule shapes, while lower HCl concentrations resulted in a mixed morphology including globules, tubes, and plate-like structures. In addition, it was found that the diameter of globule-like PANI has increased from ~266.67 nm to ~508.33 nm, when the HCl concentration was changed from 0 M to 10 M. Apparently, increasing the acidity of the COP medium promotes enlargement of the PANI size. Despite that, there is not much change in the surface functional groups of the formed PANI. Overall, this study offers insights into manipulating PANI properties by adjusting the medium acidity during the COP process. While the impacts of medium acidity on yield, morphology, and functionalities of PANI were revealed, further investigation is required to evaluate the effect on electrical properties.","PeriodicalId":16757,"journal":{"name":"Journal of Physical Science","volume":"23 5","pages":""},"PeriodicalIF":0.7,"publicationDate":"2023-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138984659","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}
D. N. K. Putra Negara, T. G. Tirta Nindhia, Cok Istri Putri Kusuma Kencanawati, I. G. A. K. Suriadi, I. Widiyarta, I. Lokantara, I. N. Budiarsa
Biomass can be utilised in place of non-renewable raw resources like coal and petroleum residue in the production of activated carbon. Each biomass, however, requires different manufacturing process parameters to obtain the desired activated carbon characteristics due to their different chemical compositions. This study aims to examine the effects of carbonisation heating rates (8°C/min, 10°C/min and 12°C/min) on the characteristics of teak sawdust-derived activated carbon. Furthermore, finding the proper carbonisation heating rate to provide the optimum characteristics is the originality of this study. Activation was carried out at a temperature of 600°C, and simultaneously, 200 mL/min of nitrogen was doped. Thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and adsorption isotherm tests were performed as part of the characterisation. The results revealed that activated carbon carbonised at a rate of 10°C/min produced the best properties. This activated carbon contained 10.8% moisture, 15.26% volatile, 1.73% ash and 72.43% fixed carbon. The majority of the structure is mesopore, with an average pore diameter of 2.43 nm, a pore volume of 0.369 cm3 /g and a specific surface area of 409.698 m2 /g. Its ability to adsorb nitrogen was 239.102 cm3 /g. The successful production of activated carbon from biomass waste derived from teak sawdust offers hope for untapped sawdust waste and has the potential to be used in a number of applications that need adsorption mechanisms.
{"title":"The Effect of Carbonisation Heating Rates on the Properties of N-Doped Teak Sawdust Waste Activated Carbon","authors":"D. N. K. Putra Negara, T. G. Tirta Nindhia, Cok Istri Putri Kusuma Kencanawati, I. G. A. K. Suriadi, I. Widiyarta, I. Lokantara, I. N. Budiarsa","doi":"10.21315/jps2023.34.3.1","DOIUrl":"https://doi.org/10.21315/jps2023.34.3.1","url":null,"abstract":"Biomass can be utilised in place of non-renewable raw resources like coal and petroleum residue in the production of activated carbon. Each biomass, however, requires different manufacturing process parameters to obtain the desired activated carbon characteristics due to their different chemical compositions. This study aims to examine the effects of carbonisation heating rates (8°C/min, 10°C/min and 12°C/min) on the characteristics of teak sawdust-derived activated carbon. Furthermore, finding the proper carbonisation heating rate to provide the optimum characteristics is the originality of this study. Activation was carried out at a temperature of 600°C, and simultaneously, 200 mL/min of nitrogen was doped. Thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and adsorption isotherm tests were performed as part of the characterisation. The results revealed that activated carbon carbonised at a rate of 10°C/min produced the best properties. This activated carbon contained 10.8% moisture, 15.26% volatile, 1.73% ash and 72.43% fixed carbon. The majority of the structure is mesopore, with an average pore diameter of 2.43 nm, a pore volume of 0.369 cm3 /g and a specific surface area of 409.698 m2 /g. Its ability to adsorb nitrogen was 239.102 cm3 /g. The successful production of activated carbon from biomass waste derived from teak sawdust offers hope for untapped sawdust waste and has the potential to be used in a number of applications that need adsorption mechanisms.","PeriodicalId":16757,"journal":{"name":"Journal of Physical Science","volume":"27 12","pages":""},"PeriodicalIF":0.7,"publicationDate":"2023-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138983886","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}
Takwa E. Ellakwa, A. A. H. Basry, Sawsan M. Abu El Hassan
The kinetics of the oxidation of the [Co(L)2(H2O)2] complex by N-bromosuccinimide (NBS) in aqueous media (L = bidentate ligand mono deprotonated anion derived from methyl salicylaldehyde and sulfacetamide) were investigated over a pH range of 4.2–5.4, temperatures ranging from 25°C to 40°C, and an ionic strength of 0.1 mol/l–0.4 mol/l for both NBS and complex concentrations. The reaction rate over the studied pH ranges was predicted to be first order NBS and complex dependent and to rise with decreasing [H+]. It was compatible with the experimental rate law to say that a process in which the complex’s dehydrogenated form is greater reactivity compared to its conjugate acid. Acrylonitrile polymerisation was tested for its abundance of free radicals in the reaction admixture. It was supposed that transfer of electrons and formation of initial cobalt(III) products, which were eventually were tardily transformed into the final cobalt(III) products, occurred by an inner-sphere mechanism.
{"title":"A Kinetic Study of Oxidation of New [Co(L)2(H2O)2] Complex by N-bromosuccinimide (NBS)","authors":"Takwa E. Ellakwa, A. A. H. Basry, Sawsan M. Abu El Hassan","doi":"10.21315/jps2023.34.3.6","DOIUrl":"https://doi.org/10.21315/jps2023.34.3.6","url":null,"abstract":"The kinetics of the oxidation of the [Co(L)2(H2O)2] complex by N-bromosuccinimide (NBS) in aqueous media (L = bidentate ligand mono deprotonated anion derived from methyl salicylaldehyde and sulfacetamide) were investigated over a pH range of 4.2–5.4, temperatures ranging from 25°C to 40°C, and an ionic strength of 0.1 mol/l–0.4 mol/l for both NBS and complex concentrations. The reaction rate over the studied pH ranges was predicted to be first order NBS and complex dependent and to rise with decreasing [H+]. It was compatible with the experimental rate law to say that a process in which the complex’s dehydrogenated form is greater reactivity compared to its conjugate acid. Acrylonitrile polymerisation was tested for its abundance of free radicals in the reaction admixture. It was supposed that transfer of electrons and formation of initial cobalt(III) products, which were eventually were tardily transformed into the final cobalt(III) products, occurred by an inner-sphere mechanism.","PeriodicalId":16757,"journal":{"name":"Journal of Physical Science","volume":"25 4","pages":""},"PeriodicalIF":0.7,"publicationDate":"2023-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138984197","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}
The spectrophotometric method monitored the uncatalysed redox reaction between Mn+7/H+ ions and mannose sugar molecules kinetically at constant ionic strength maintained using potassium nitrate (KNO3). The kinetic study showed that the reaction was pseudo-first order concerning Mn+7 and mannose, and the rate of reaction increases by increasing the concentration of Mn+7, mannose and H+ and increasing temperature. The reaction rate was enhanced by 3 × 10–4m of Mn+7 concentration, and the oxidation with Mn+7 was faster using 2 × 10–2m of mannose and 5 × 10–1m of H+. The temperature dependence was carried out under fixed experimental conditions, from which the activation energy of the reaction (Ea) in KJ.mol–1 was found to be 61.1, and the frequency factor (A) in sec–1 was 10.52 × 105 other physical functions, namely, the free energy change (∆G) in KJ.mol–1 and the entropy change (∆S) in J.K –1 were also calculated at different temperatures. Qualitative analysis of the reaction products revealed the formation of formic acid. A rate law was derived from the proposed mechanism, which agreed well with experimental kinetics.
{"title":"The Kinetic Behaviour of Mn+7/H+ Ions Towards Mannose Molecule","authors":"Mustafa Jaip Allah Abdelmageed Abualreish","doi":"10.21315/jps2023.34.3.2","DOIUrl":"https://doi.org/10.21315/jps2023.34.3.2","url":null,"abstract":"The spectrophotometric method monitored the uncatalysed redox reaction between Mn+7/H+ ions and mannose sugar molecules kinetically at constant ionic strength maintained using potassium nitrate (KNO3). The kinetic study showed that the reaction was pseudo-first order concerning Mn+7 and mannose, and the rate of reaction increases by increasing the concentration of Mn+7, mannose and H+ and increasing temperature. The reaction rate was enhanced by 3 × 10–4m of Mn+7 concentration, and the oxidation with Mn+7 was faster using 2 × 10–2m of mannose and 5 × 10–1m of H+. The temperature dependence was carried out under fixed experimental conditions, from which the activation energy of the reaction (Ea) in KJ.mol–1 was found to be 61.1, and the frequency factor (A) in sec–1 was 10.52 × 105 other physical functions, namely, the free energy change (∆G) in KJ.mol–1 and the entropy change (∆S) in J.K –1 were also calculated at different temperatures. Qualitative analysis of the reaction products revealed the formation of formic acid. A rate law was derived from the proposed mechanism, which agreed well with experimental kinetics.","PeriodicalId":16757,"journal":{"name":"Journal of Physical Science","volume":"18 6","pages":""},"PeriodicalIF":0.7,"publicationDate":"2023-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138984572","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}
Electron beam irradiation (EBI) (100−400 kGy) was utilised to pretreat water hyacinth (WH). Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), fourier transform infrared (FTIR), UV-vis absorption and fluorescence spectroscopy were used to examine the effects of EBI and hydrothermal temperatures on the physical, chemical and optical characteristics of carbon dots (CDs). The combination of 400 kGy-pretreatment and 250°C-hydrothermal treatment as the optimal condition for CDs synthesis provided the highest quantum yield (QY) of 14.5% and the product yield of 7.5%. Using dynamic light scattering (DLS), the CDs showed an average size of around 180 nm, and the zeta potential analysis revealed the overall negative charge on the CDs’ surface. In comparison, the CDs synthesised via hydrothermal conversion at 250°C without EBI showed a QY of only 4.0% and a product yield of 3.8%, significantly lower than the condition with 400 kGy-pretreatment. The improved optical characteristics of the CDs could result from the high nitrogen contents of WH biomass, oxygen-rich surfaces from EBI pretreatment at 400 kGy and the aromatic skeleton of the CDs.
{"title":"Irradiation-Assisted Hydrothermal Conversion of Water Hyacinth Leaves to Fluorescence Carbon Dots with High Quantum Yield","authors":"Tanagorn Kwamman, Threeraphat Chutimasakul, Panida Sangangam, Nattamon Puengposop, Pattanapong Thangsunan, Tinutda Phonlam, Kanokorn Wechakorn","doi":"10.21315/jps2023.34.2.4","DOIUrl":"https://doi.org/10.21315/jps2023.34.2.4","url":null,"abstract":"Electron beam irradiation (EBI) (100−400 kGy) was utilised to pretreat water hyacinth (WH). Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), fourier transform infrared (FTIR), UV-vis absorption and fluorescence spectroscopy were used to examine the effects of EBI and hydrothermal temperatures on the physical, chemical and optical characteristics of carbon dots (CDs). The combination of 400 kGy-pretreatment and 250°C-hydrothermal treatment as the optimal condition for CDs synthesis provided the highest quantum yield (QY) of 14.5% and the product yield of 7.5%. Using dynamic light scattering (DLS), the CDs showed an average size of around 180 nm, and the zeta potential analysis revealed the overall negative charge on the CDs’ surface. In comparison, the CDs synthesised via hydrothermal conversion at 250°C without EBI showed a QY of only 4.0% and a product yield of 3.8%, significantly lower than the condition with 400 kGy-pretreatment. The improved optical characteristics of the CDs could result from the high nitrogen contents of WH biomass, oxygen-rich surfaces from EBI pretreatment at 400 kGy and the aromatic skeleton of the CDs.","PeriodicalId":16757,"journal":{"name":"Journal of Physical Science","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135236171","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}
Ahmad Solehin Ab Sabar, Syaza Azhari, Nur Atiqah Nasir, Muhammad Zamir Othman
A direct, simple and low-cost approach to synthesising carbon aerogelmagnesium (CA-Mg) composites has been demonstrated in this research. It is conducted by carbonising sodium carboxymethyl cellulose (CMC) aerogels via a sol-gel and freezedrying process. Mg is used as an enhancer for CA in the preparation step and as a selective candidate for the hydrogen storage device. Note that the structure and morphology of CA-Mg composites are characterised using field emission scanning electron microscopy (FESEM), fourier transforms infrared spectroscopy (FTIR) and X-ray diffraction (XRD) techniques. The ability of CA-Mg composites to act as a hydrogen storage device is analysed by utilising Brunauer-Emmett-Teller (BET) and temperature-programmed desorption analysis. The CA-Mg composites comprise porous structures with a high specific surface area of 101.4407 m2 /g, and 0.002 mol of Mg2+ is the optimum concentration for synthesising CA-Mg composites. As a potential candidate for a hydrogen storage device, the CA-Mg composites show an initial dehydrogenation temperature of 377.22°C, where they desorbed the maximum amount of hydrogen gas. This study emphasises the potential for using CA as a hydrogen storage device, which fulfils the seventh goal of the Sustainable Development Goals (SDGs), affordable and clean energy, as well as Department of Energy (DOE)’s goal of using carbon-based materials.
{"title":"Synthesis and Characterisation of Carbon Aerogel Derived from Carboxymethyl Cellulose as Hydrogen Storage Material","authors":"Ahmad Solehin Ab Sabar, Syaza Azhari, Nur Atiqah Nasir, Muhammad Zamir Othman","doi":"10.21315/jps2023.34.2.2","DOIUrl":"https://doi.org/10.21315/jps2023.34.2.2","url":null,"abstract":"A direct, simple and low-cost approach to synthesising carbon aerogelmagnesium (CA-Mg) composites has been demonstrated in this research. It is conducted by carbonising sodium carboxymethyl cellulose (CMC) aerogels via a sol-gel and freezedrying process. Mg is used as an enhancer for CA in the preparation step and as a selective candidate for the hydrogen storage device. Note that the structure and morphology of CA-Mg composites are characterised using field emission scanning electron microscopy (FESEM), fourier transforms infrared spectroscopy (FTIR) and X-ray diffraction (XRD) techniques. The ability of CA-Mg composites to act as a hydrogen storage device is analysed by utilising Brunauer-Emmett-Teller (BET) and temperature-programmed desorption analysis. The CA-Mg composites comprise porous structures with a high specific surface area of 101.4407 m2 /g, and 0.002 mol of Mg2+ is the optimum concentration for synthesising CA-Mg composites. As a potential candidate for a hydrogen storage device, the CA-Mg composites show an initial dehydrogenation temperature of 377.22°C, where they desorbed the maximum amount of hydrogen gas. This study emphasises the potential for using CA as a hydrogen storage device, which fulfils the seventh goal of the Sustainable Development Goals (SDGs), affordable and clean energy, as well as Department of Energy (DOE)’s goal of using carbon-based materials.","PeriodicalId":16757,"journal":{"name":"Journal of Physical Science","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134932018","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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