Slow evaporation method was adopted to grow barium succinate (BS) single crystals for the first time and diamond shape crystals were successfully synthesised with dimension 14 mm3 × 17 mm3 × 4 mm3. Single crystal x-ray diffraction studies show that the crystal system is monoclinic. Powder x-ray diffraction studies confirmed the crystallinity of the grown BS crystal. From energy dispersive x-ray spectroscopy (EDS) analysis the presence of barium metal was confirmed. The functional group of the BS crystal was confirmed from fourier transform infrared (FTIR) spectrum. The crystals were found to be hydrated and thermally stable up to 150°C. BS crystal possesses good transmittance in the wavelength range 250 nm–1200 nm and it is non-linear optical (NLO) active material. The BS crystals have mechanical softness and normal dielectric behaviour.
{"title":"Study of Physico-Chemical Properties and Growth Dimension Augmentation of Barium Succinate Single Crystals Grown by Slow Evaporation Technique","authors":"Christy D. S., Sahaya Shajan X., Mahadevan C. K.","doi":"10.21315/jps2022.33.1.3","DOIUrl":"https://doi.org/10.21315/jps2022.33.1.3","url":null,"abstract":"Slow evaporation method was adopted to grow barium succinate (BS) single crystals for the first time and diamond shape crystals were successfully synthesised with dimension 14 mm3 × 17 mm3 × 4 mm3. Single crystal x-ray diffraction studies show that the crystal system is monoclinic. Powder x-ray diffraction studies confirmed the crystallinity of the grown BS crystal. From energy dispersive x-ray spectroscopy (EDS) analysis the presence of barium metal was confirmed. The functional group of the BS crystal was confirmed from fourier transform infrared (FTIR) spectrum. The crystals were found to be hydrated and thermally stable up to 150°C. BS crystal possesses good transmittance in the wavelength range 250 nm–1200 nm and it is non-linear optical (NLO) active material. The BS crystals have mechanical softness and normal dielectric behaviour.","PeriodicalId":16757,"journal":{"name":"Journal of Physical Science","volume":"46 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85443674","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}
Acrylic resin is the dominant material that is broadly utilised to produce partial and complete dentures. The exposure of the denture-base acrylic resins to the oral environment as well as storing media for a certain period causes saliva sorption. In this study, composite materials-based polymethylmethacrylate (PMMA) reinforced with 1 wt% of glass fibres and (3, 6 and 9 wt%) yttrium oxide (Y2O3 ) have been prepared, and the addition influence upon some mechanical tests (tensile, flexural, hardness and surface roughness) has been investigated. Afterward, the mechanical properties of composite materials afterimmersion in artificialsaliva forseven days have been evaluated. The results show that the Y2O3 percentage is 6%, which possesses a perfect feature. Thus, such a sample may be an encouraging material for achieving the needed properties for denture use. Furthermore, all mechanical properties were decreased after immersion in synthetic saliva.
{"title":"Assessment of the Mechanical Properties of Hybrid Polymer Composites for Denture Applications","authors":"J. K. Oleiwi, A. A. Mohammed","doi":"10.21315/jps2022.33.1.6","DOIUrl":"https://doi.org/10.21315/jps2022.33.1.6","url":null,"abstract":"Acrylic resin is the dominant material that is broadly utilised to produce partial and complete dentures. The exposure of the denture-base acrylic resins to the oral environment as well as storing media for a certain period causes saliva sorption. In this study, composite materials-based polymethylmethacrylate (PMMA) reinforced with 1 wt% of glass fibres and (3, 6 and 9 wt%) yttrium oxide (Y2O3 ) have been prepared, and the addition influence upon some mechanical tests (tensile, flexural, hardness and surface roughness) has been investigated. Afterward, the mechanical properties of composite materials afterimmersion in artificialsaliva forseven days have been evaluated. The results show that the Y2O3 percentage is 6%, which possesses a perfect feature. Thus, such a sample may be an encouraging material for achieving the needed properties for denture use. Furthermore, all mechanical properties were decreased after immersion in synthetic saliva.","PeriodicalId":16757,"journal":{"name":"Journal of Physical Science","volume":"17 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75619789","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. K. Chaudhary, Yogesh Singh Maharjan, Sanju Shrestha, Surendra Maharjan, S. Shrestha, L. Joshi
Monitoring and remediation of toxic and flammable gases have become a critical task for the development of a clean society. Among various types of metal oxide semiconductors (MOS), zinc oxide (ZnO) is considered a potential material for gas sensing application because of its high sensitivity, easy synthesis, and high thermal stability behaviours. This research aimed to gain an in-depth understanding of the sensing task of a very stable and porous thin film of spin coated ZnO for detecting toxic ammonia vapour at room temperature. As-prepared ZnO films were characterised by x-ray diffraction (XRD), scanning electron microscopy (SEM), and ultraviolet-visible (UV-vis) analyses. XRD and SEM results revealed the polycrystalline wurtzite ZnO phase with grainy surface morphology. Optical calculations quantify the direct band gap of ZnO as 3.2 eV. The sensitivity measurements showed a good response ratio of 38.5 ± 0.6 with an exposure of 400 ppm of ammonia vapour. The results on sensitivity measurement of several cycles illustrated its stability and sensing performance better than other reported similar works. These findings will be useful to develop a low cost and efficient room temperature MOS gas sensor that can efficiently detect extremely low concentrations as 20 ppm of ammonia vapour which is below the Occupational Safety and Health Administration (OSHA) recommended value.
{"title":"Sensing Performance of a ZnO-based Ammonia Sensor","authors":"D. K. Chaudhary, Yogesh Singh Maharjan, Sanju Shrestha, Surendra Maharjan, S. Shrestha, L. Joshi","doi":"10.21315/jps2022.33.1.7","DOIUrl":"https://doi.org/10.21315/jps2022.33.1.7","url":null,"abstract":"Monitoring and remediation of toxic and flammable gases have become a critical task for the development of a clean society. Among various types of metal oxide semiconductors (MOS), zinc oxide (ZnO) is considered a potential material for gas sensing application because of its high sensitivity, easy synthesis, and high thermal stability behaviours. This research aimed to gain an in-depth understanding of the sensing task of a very stable and porous thin film of spin coated ZnO for detecting toxic ammonia vapour at room temperature. As-prepared ZnO films were characterised by x-ray diffraction (XRD), scanning electron microscopy (SEM), and ultraviolet-visible (UV-vis) analyses. XRD and SEM results revealed the polycrystalline wurtzite ZnO phase with grainy surface morphology. Optical calculations quantify the direct band gap of ZnO as 3.2 eV. The sensitivity measurements showed a good response ratio of 38.5 ± 0.6 with an exposure of 400 ppm of ammonia vapour. The results on sensitivity measurement of several cycles illustrated its stability and sensing performance better than other reported similar works. These findings will be useful to develop a low cost and efficient room temperature MOS gas sensor that can efficiently detect extremely low concentrations as 20 ppm of ammonia vapour which is below the Occupational Safety and Health Administration (OSHA) recommended value.","PeriodicalId":16757,"journal":{"name":"Journal of Physical Science","volume":"29 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77867617","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}
Hydroxyapatite (HA) has great potential as a reinforcing filler for poly (methyl methacrylate) (PMMA) denture base materials. Nevertheless, filler particles need to be homogeneously distributed throughout the PMMA particles to get the maximum benefit from using the filler. Therefore, the physical mixing of the powder components (PMMA and the filler) is strongly preferred to provide the required dispersion of the filler in the matrix. However, conventional techniques that have been tried, such as hand mixing and stirrer mixing techniques, were not effective. Therefore, the current study was designed to experimentally investigate the effect of different mixing times on the fracture toughness of PMMA/HA using a developed ball milling method. In this study, heat cured PMMA reinforced with 15 wt% HA ceramic powder was ground for different times (i.e., 10, 20, 30, and 40 min) via the technique of planetary ball milling (PBM). The ground powder mixtures were used for the fabrication of denture base testing samples. The particle size and distribution of the PMMA/HA composites after milling for several times were determined by the laser light scattering technique. The X-ray diffraction (XRD) patterns of the PMMA/HA composites were obtained. However, no new phase was observed. The effects of mixing time using the PBM technique on the fracture toughness were investigated. The effect of mixing time on the microporosity (voids) on the fractured surface of PMMA/HA was studied with field emission scanning electron microscopy (FESEM). Within the limitation of the current study, 30 min is considered the optimum mixing time for the tested PMMA/HA composite.
{"title":"Fracture Toughness of Poly (Methyl Methacrylate)/Hydroxyapatite Denture Base Composite: Effect of Planetary Ball Milling Mixing Time","authors":"Jamal Moammar Aldabib, Z. M. Mohd Ishak","doi":"10.21315/jps2021.32.3.8","DOIUrl":"https://doi.org/10.21315/jps2021.32.3.8","url":null,"abstract":"Hydroxyapatite (HA) has great potential as a reinforcing filler for poly (methyl methacrylate) (PMMA) denture base materials. Nevertheless, filler particles need to be homogeneously distributed throughout the PMMA particles to get the maximum benefit from using the filler. Therefore, the physical mixing of the powder components (PMMA and the filler) is strongly preferred to provide the required dispersion of the filler in the matrix. However, conventional techniques that have been tried, such as hand mixing and stirrer mixing techniques, were not effective. Therefore, the current study was designed to experimentally investigate the effect of different mixing times on the fracture toughness of PMMA/HA using a developed ball milling method. In this study, heat cured PMMA reinforced with 15 wt% HA ceramic powder was ground for different times (i.e., 10, 20, 30, and 40 min) via the technique of planetary ball milling (PBM). The ground powder mixtures were used for the fabrication of denture base testing samples. The particle size and distribution of the PMMA/HA composites after milling for several times were determined by the laser light scattering technique. The X-ray diffraction (XRD) patterns of the PMMA/HA composites were obtained. However, no new phase was observed. The effects of mixing time using the PBM technique on the fracture toughness were investigated. The effect of mixing time on the microporosity (voids) on the fractured surface of PMMA/HA was studied with field emission scanning electron microscopy (FESEM). Within the limitation of the current study, 30 min is considered the optimum mixing time for the tested PMMA/HA composite.","PeriodicalId":16757,"journal":{"name":"Journal of Physical Science","volume":"2012 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2021-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74214276","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}
Dylan Jia Yee Tong, S. Koay, M. Chan, K. Tshai, T. K. Ong, Y. Buys
Electric Discharge Machining (EDM) process uses electrodes made from graphite that wear out over time and are turned into scrap. In this research, EDM electrode scraps were recycled and turned into graphite powder (rGP). This rGP was used as a conductive filler to produce conductive polymer composite (CPC) material by combining it with polypropylene (PP) resin via melt compounding and compression moulding processes. The percolation threshold of this composite material changed when 30 wt% of rGP was added, whereby the insulative material changed became antistatic. The composite was able to achieve surface resistivity as low as 105 ohm/sq. However, the addition of higher rGP content deteriorated the tensile properties of composite, whereby the tensile strength of composite significantly decreased as compared to neat PP. The results also showed that the tensile modulus of this composite became higher, and the material became more brittle as compared to neat PP. However, the PP/rGP composite with 50 wt% filler content reduced the tensile modulus due to plasticising effect caused by the agglomeration of rGP. The addition of high filler content on PP/rGP composite also caused an increase in processing torque. This was due to the restriction of rGP particles to the melt flow of molten PP. The morphological analysis found that the PP/rGP composites with higher amounts of filler content were highly agglomerated and formed conductivity paths within the PP matrix. The increase of rGP content highly improved the thermal stability of composite. The findings of this study show that the rGP has the potential to be used as a conductive filler for producing conductive composite material.
{"title":"Conductive Polymer Composites Made from Polypropylene and Recycled Graphite Scrap","authors":"Dylan Jia Yee Tong, S. Koay, M. Chan, K. Tshai, T. K. Ong, Y. Buys","doi":"10.21315/jps2021.32.3.3","DOIUrl":"https://doi.org/10.21315/jps2021.32.3.3","url":null,"abstract":"Electric Discharge Machining (EDM) process uses electrodes made from graphite that wear out over time and are turned into scrap. In this research, EDM electrode scraps were recycled and turned into graphite powder (rGP). This rGP was used as a conductive filler to produce conductive polymer composite (CPC) material by combining it with polypropylene (PP) resin via melt compounding and compression moulding processes. The percolation threshold of this composite material changed when 30 wt% of rGP was added, whereby the insulative material changed became antistatic. The composite was able to achieve surface resistivity as low as 105 ohm/sq. However, the addition of higher rGP content deteriorated the tensile properties of composite, whereby the tensile strength of composite significantly decreased as compared to neat PP. The results also showed that the tensile modulus of this composite became higher, and the material became more brittle as compared to neat PP. However, the PP/rGP composite with 50 wt% filler content reduced the tensile modulus due to plasticising effect caused by the agglomeration of rGP. The addition of high filler content on PP/rGP composite also caused an increase in processing torque. This was due to the restriction of rGP particles to the melt flow of molten PP. The morphological analysis found that the PP/rGP composites with higher amounts of filler content were highly agglomerated and formed conductivity paths within the PP matrix. The increase of rGP content highly improved the thermal stability of composite. The findings of this study show that the rGP has the potential to be used as a conductive filler for producing conductive composite material.","PeriodicalId":16757,"journal":{"name":"Journal of Physical Science","volume":"49 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2021-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79096240","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}
Multifunctional magneto-luminescent nanoparticles (NPs) were synthesised by an ultrasonic wave-assisted Stöber method. The multifunctional NPs are composed of magnetic NPs (Fe3O4) and photoluminescent quantum dots (QDs) (ZnS:Mn) in amorphous silica (SiO2) matrix, which was confirmed by X-ray diffraction, Raman scattering spectroscopy, and transmission electron microscopy (TEM). The multifunctional NPs have high saturation magnetisation at room temperature simultaneously with strong photoluminescence (PL) in visible light, which is promising for biomedical applications.
{"title":"Synthesis and Characteristics of Multifunctional Magneto-luminescent Nanoparticles by an Ultrasonic Wave-assisted Stӧber Method","authors":"Tien-Dung Chu, H. Nguyen","doi":"10.21315/jps2021.32.3.6","DOIUrl":"https://doi.org/10.21315/jps2021.32.3.6","url":null,"abstract":"Multifunctional magneto-luminescent nanoparticles (NPs) were synthesised by an ultrasonic wave-assisted Stöber method. The multifunctional NPs are composed of magnetic NPs (Fe3O4) and photoluminescent quantum dots (QDs) (ZnS:Mn) in amorphous silica (SiO2) matrix, which was confirmed by X-ray diffraction, Raman scattering spectroscopy, and transmission electron microscopy (TEM). The multifunctional NPs have high saturation magnetisation at room temperature simultaneously with strong photoluminescence (PL) in visible light, which is promising for biomedical applications.","PeriodicalId":16757,"journal":{"name":"Journal of Physical Science","volume":"5 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2021-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89566571","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}
This research project investigates the mechanical properties of the corn husk fibre reinforced unsaturated polyester composite (CHFPC) and hybrid fibre (corn husk/flax) reinforced unsaturated polyester composite (HFPC) at different fibre orientations. The tensile and flexural properties of CHFPC and HFPC were manipulated by the different degrees of fibre orientations of 0°, 45°, and 90°. Both CHFPC and HFPC with 0° of fibre orientation had the highest tensile strength and flexural strength. Moreover, the tensile and flexural modulus of specimens with 0° orientation had the highest result compared to 45° and 90° orientations. However, for the elongation at break during tensile testing, 0° orientation had the highest strain, more than unsaturated polyester (UPR) and other composites. The tensile and flexural strengths of HFPC specimens with 0° fibre orientation were higher than that of CHFPC. Besides, the tensile modulus and flexural modulus of HFPC also increased as compared to CHFPC. The elongation at break of HFPC for tensile testing had the highest strain compared to CHFPC. The results showed that the mechanical properties of the hybrid fibre composite performed better compared to the single fibre composite. Moreover, the corn husk fibre (CHF) and flax fibre (FF) acted as reinforcements to enhance the mechanical properties of the UPR composites.
{"title":"Preliminary Study of the Mechanical Properties of Hybrid Fibres Reinforced Unsaturated Polyester Composites","authors":"Chek Shin Tan, M. Chan, S. Koay","doi":"10.21315/jps2021.32.3.4","DOIUrl":"https://doi.org/10.21315/jps2021.32.3.4","url":null,"abstract":"This research project investigates the mechanical properties of the corn husk fibre reinforced unsaturated polyester composite (CHFPC) and hybrid fibre (corn husk/flax) reinforced unsaturated polyester composite (HFPC) at different fibre orientations. The tensile and flexural properties of CHFPC and HFPC were manipulated by the different degrees of fibre orientations of 0°, 45°, and 90°. Both CHFPC and HFPC with 0° of fibre orientation had the highest tensile strength and flexural strength. Moreover, the tensile and flexural modulus of specimens with 0° orientation had the highest result compared to 45° and 90° orientations. However, for the elongation at break during tensile testing, 0° orientation had the highest strain, more than unsaturated polyester (UPR) and other composites. The tensile and flexural strengths of HFPC specimens with 0° fibre orientation were higher than that of CHFPC. Besides, the tensile modulus and flexural modulus of HFPC also increased as compared to CHFPC. The elongation at break of HFPC for tensile testing had the highest strain compared to CHFPC. The results showed that the mechanical properties of the hybrid fibre composite performed better compared to the single fibre composite. Moreover, the corn husk fibre (CHF) and flax fibre (FF) acted as reinforcements to enhance the mechanical properties of the UPR composites.","PeriodicalId":16757,"journal":{"name":"Journal of Physical Science","volume":"42 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2021-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76160555","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}
E. Alias, M. M. Md Taib, A. S. Abu Bakar, T. Egawa, A. Kent, W. M. Wan Ahmad Kamil, N. Zainal
A crack-free indium gallium nitride (InGaN) based light emitting diode (LED) grown on silicon (Si) substrate was successfully demonstrated by introducing aluminium nitride/gallium nitride (AlN/GaN) superlattice structure (SLS) in the growth of the LED. The luminescence and the crystalline properties of the LED were discussed. From photoluminescence (PL) surface mapping measurement, the emission wavelength of the LED (453 nm) was almost uniform across the LED epi-wafer area. Temperaturedependent PL revealed that the dominant emission peak of the LED was 2.77 eV at all temperatures. The emission peak was related to the quantum wells of the LED. Some additional peaks were also observed, in particular at lower temperatures. These peaks were associated to alloy fluctuations in the In0.11Ga0.89N/ In0.02Ga0.98N multiquantum wells (MQWs) of the LED. Furthermore, the dependence of PL intensity and PL decay time on temperature revealed the evidence related to indium and/or interface fluctuations of the quantum wells. From X-ray diffraction (XRD) ω-scan measurements, fringes of the AlN/GaN SLS were clear, indicating the SLS were grown with good interface abruptness. However, the fringes for the MQWs were less uniform, indicating another evidence of the alloy fluctuations in the MQWs. XRD-reciprocal surface mapping (RSM) measurement showed that all epitaxial layers of the LED were grown coherently, and the LED was fully under strain.
{"title":"Luminescence and Crystalline Properties of InGaN-based LED on Si Substrate with AlN/GaN Superlattice Structure","authors":"E. Alias, M. M. Md Taib, A. S. Abu Bakar, T. Egawa, A. Kent, W. M. Wan Ahmad Kamil, N. Zainal","doi":"10.21315/jps2021.32.3.1","DOIUrl":"https://doi.org/10.21315/jps2021.32.3.1","url":null,"abstract":"A crack-free indium gallium nitride (InGaN) based light emitting diode (LED) grown on silicon (Si) substrate was successfully demonstrated by introducing aluminium nitride/gallium nitride (AlN/GaN) superlattice structure (SLS) in the growth of the LED. The luminescence and the crystalline properties of the LED were discussed. From photoluminescence (PL) surface mapping measurement, the emission wavelength of the LED (453 nm) was almost uniform across the LED epi-wafer area. Temperaturedependent PL revealed that the dominant emission peak of the LED was 2.77 eV at all temperatures. The emission peak was related to the quantum wells of the LED. Some additional peaks were also observed, in particular at lower temperatures. These peaks were associated to alloy fluctuations in the In0.11Ga0.89N/ In0.02Ga0.98N multiquantum wells (MQWs) of the LED. Furthermore, the dependence of PL intensity and PL decay time on temperature revealed the evidence related to indium and/or interface fluctuations of the quantum wells. From X-ray diffraction (XRD) ω-scan measurements, fringes of the AlN/GaN SLS were clear, indicating the SLS were grown with good interface abruptness. However, the fringes for the MQWs were less uniform, indicating another evidence of the alloy fluctuations in the MQWs. XRD-reciprocal surface mapping (RSM) measurement showed that all epitaxial layers of the LED were grown coherently, and the LED was fully under strain.","PeriodicalId":16757,"journal":{"name":"Journal of Physical Science","volume":"60 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2021-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74969263","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}
Geophysicists use electrical methods to investigate and characterise the earth’s subsurface geology. This study aims to evaluate the performance of copper and conventional stainless-steel electrodes in subsurface tomographic investigations using electrical resistivity tomography (ERT) and induced polarisation (IP) at two sites in Penang, Malaysia. Site 1 and Site 2 employed profile lengths of 200 m and 100 m, with electrodes spacing of 5.0 m and 2.5 m, respectively. In the results of the final data inversion, it was observed that the ERT and IP tomographic models of Site 1 have the best convergence limits with percentage relative differences (copper as reference model) ranging from –70% to 70%, while Site 2 recorded –8% to 8%. The electrodes performance evaluation showed that population root mean square (RMS) error and population mean absolute percentage error (MAPE) of data points between copper and stainless-steel electrodes yielded large values for Site 1 with values above 28% and that of Site 2 was less than 4%. Hence, copper (good electrical conductivity and non-polarisable) electrodes have improved the quality and quantity of infield data which give low values of population RMS error and population MAPE compared to conventional stainless-steel electrodes, especially for large unit electrode spacing surveys. Most notably, this work has contributed to the understanding of the capability of copper electrodes in providing precise and reliable inversion models for subsurface tomographic investigations in pre- and post-land uses (engineering work), hydrogeology/groundwater, environmental studies, etc.
{"title":"Performance Evaluation of Copper and Stainless-steel Electrodes in Electrical Tomographic Imaging","authors":"Adedibu Sunny Akingboye, A. A. Bery","doi":"10.21315/jps2021.32.3.2","DOIUrl":"https://doi.org/10.21315/jps2021.32.3.2","url":null,"abstract":"Geophysicists use electrical methods to investigate and characterise the earth’s subsurface geology. This study aims to evaluate the performance of copper and conventional stainless-steel electrodes in subsurface tomographic investigations using electrical resistivity tomography (ERT) and induced polarisation (IP) at two sites in Penang, Malaysia. Site 1 and Site 2 employed profile lengths of 200 m and 100 m, with electrodes spacing of 5.0 m and 2.5 m, respectively. In the results of the final data inversion, it was observed that the ERT and IP tomographic models of Site 1 have the best convergence limits with percentage relative differences (copper as reference model) ranging from –70% to 70%, while Site 2 recorded –8% to 8%. The electrodes performance evaluation showed that population root mean square (RMS) error and population mean absolute percentage error (MAPE) of data points between copper and stainless-steel electrodes yielded large values for Site 1 with values above 28% and that of Site 2 was less than 4%. Hence, copper (good electrical conductivity and non-polarisable) electrodes have improved the quality and quantity of infield data which give low values of population RMS error and population MAPE compared to conventional stainless-steel electrodes, especially for large unit electrode spacing surveys. Most notably, this work has contributed to the understanding of the capability of copper electrodes in providing precise and reliable inversion models for subsurface tomographic investigations in pre- and post-land uses (engineering work), hydrogeology/groundwater, environmental studies, etc.","PeriodicalId":16757,"journal":{"name":"Journal of Physical Science","volume":"47 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2021-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79354589","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}
Petroleum-based plastics have had a long history with varied materials and applications. However, the major drawback with these plastics is their harmful impact on the environment. Poor disposal management of these plastics have ultimately affected humans. Therefore, starch-based bioplastics have been widely used because of their renewability, sustainability and cost-effectiveness. This work investigated the effect of different concentrations of corn starch (10%, 15%, and 20% w/w of distilled water) and glycerol (20%, 30%, and 40% w/v of corn starch) on the properties of corn-based bioplastic films. Particularly, mechanical (tensile strength, Young’s modulus and elongation at break) and physical (water absorption rate and moisture content) properties were investigated. These films were prepared by the solvent casting method. It was demonstrated that the addition of 30% glycerol produced mechanical properties closest to the standard value, while films with a composition of 15% of corn starch had the most optimised value. Meanwhile, 20% glycerol and 20% corn starch produced a film with high strength and stiffness but lacked flexibility. Higher concentrations of starch and glycerol produced the highest moisture and water absorption rate. This was due to the highly hydrophilic nature of both corn starch and glycerol. However, the concentration of glycerol needs to be adjusted based on the intended use of the film. In conclusion, the concentration of corn starch and glycerol produced slightly different outcomes. Thus, the properties and application of the cornbased bioplastic films can be maximised by optimising the concentration of corn starch and glycerol.
{"title":"The Physical and Mechanical Properties of Corn-based Bioplastic Films with Different Starch and Glycerol Content","authors":"Nur Nadia Nasir, Siti Amira Othman","doi":"10.21315/jps2021.32.3.7","DOIUrl":"https://doi.org/10.21315/jps2021.32.3.7","url":null,"abstract":"Petroleum-based plastics have had a long history with varied materials and applications. However, the major drawback with these plastics is their harmful impact on the environment. Poor disposal management of these plastics have ultimately affected humans. Therefore, starch-based bioplastics have been widely used because of their renewability, sustainability and cost-effectiveness. This work investigated the effect of different concentrations of corn starch (10%, 15%, and 20% w/w of distilled water) and glycerol (20%, 30%, and 40% w/v of corn starch) on the properties of corn-based bioplastic films. Particularly, mechanical (tensile strength, Young’s modulus and elongation at break) and physical (water absorption rate and moisture content) properties were investigated. These films were prepared by the solvent casting method. It was demonstrated that the addition of 30% glycerol produced mechanical properties closest to the standard value, while films with a composition of 15% of corn starch had the most optimised value. Meanwhile, 20% glycerol and 20% corn starch produced a film with high strength and stiffness but lacked flexibility. Higher concentrations of starch and glycerol produced the highest moisture and water absorption rate. This was due to the highly hydrophilic nature of both corn starch and glycerol. However, the concentration of glycerol needs to be adjusted based on the intended use of the film. In conclusion, the concentration of corn starch and glycerol produced slightly different outcomes. Thus, the properties and application of the cornbased bioplastic films can be maximised by optimising the concentration of corn starch and glycerol.","PeriodicalId":16757,"journal":{"name":"Journal of Physical Science","volume":"815 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2021-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74873331","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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