Recent finding of “Penang Woman” skeleton in Guar Kepah, Penang, Malaysia has triggered researchers to discover more archaeological remains inside the area. Some part has been excavated, exposing some shell mound where the skeleton was found. It is believed that the shell mound remarks the burial place of people in early age civilisation. More excavation processes need to be conducted in the area to see if any more skeleton, monument and pottery could be found. 2-D resistivity method was carried out in the study area to determine resistivity value of shell mound and locate another possible shell mound. Pole-dipole array was used along four survey lines where one of the survey lines is conducted on the existing shell mound while the rest are on undisturbed ground in the study area. The data were processed by using Res2Dinv software. The results show that the resistivity value of the exposed shell mound is within the range of 100 Ωm to 200 Ωm. This value was used as the reference in predicting possible shell mound on the other survey lines. Some part of the other survey lines shows the same resistivity value as the existing mound. Therefore, it can be predicted as shell mound.
{"title":"Shell Mound Investigation at Guar Kepah (Penang, Malaysia) Using 2-D Resistivity Imaging for Archaeological Study","authors":"Nazrin Rahman, N. Ismail, M. Saidin","doi":"10.21315/JPS2019.30.1.2","DOIUrl":"https://doi.org/10.21315/JPS2019.30.1.2","url":null,"abstract":"Recent finding of “Penang Woman” skeleton in Guar Kepah, Penang, Malaysia has triggered researchers to discover more archaeological remains inside the area. Some part has been excavated, exposing some shell mound where the skeleton was found. It is believed that the shell mound remarks the burial place of people in early age civilisation. More excavation processes need to be conducted in the area to see if any more skeleton, monument and pottery could be found. 2-D resistivity method was carried out in the study area to determine resistivity value of shell mound and locate another possible shell mound. Pole-dipole array was used along four survey lines where one of the survey lines is conducted on the existing shell mound while the rest are on undisturbed ground in the study area. The data were processed by using Res2Dinv software. The results show that the resistivity value of the exposed shell mound is within the range of 100 Ωm to 200 Ωm. This value was used as the reference in predicting possible shell mound on the other survey lines. Some part of the other survey lines shows the same resistivity value as the existing mound. Therefore, it can be predicted as shell mound.","PeriodicalId":16757,"journal":{"name":"Journal of Physical Science","volume":"48 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2019-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87306003","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}
Munasir, Triwikantoro, M. Zainuri, R. Bäßler, Darminto
The fabrication and characteristics of amorphous silica reinforced Al matrix composites are studied in this paper. The major starting materials were commercial Al powder and extracted nanoparticle SiO2 (NPS) powder from Indonesian silica sands. Two different active solutions,namely N-butanol and tetramethylammonium hydroxide (TMAH), were introduced during synthesis. Characterisations in terms of physical, mechanical, microstructural and corrosion rate examinations were also employed. Introducing the SiO2 nanoparticles into the Al matrix has decreased the density and increased the porosity of the composites. The addition of N-butanol into Al/SiO2(Al/SiO2(B)) led to broader and lower X-ray diffraction profiles than the addition of TMAH (Al/SiO2(T)). From the microstructural analysis, we found that the SiO2 particles enter and agglomerate into the opening gap of the Al sheets. Furthermore, yield strength, ultimate compression strength and modulus of elasticity tended to reduce the addition of SiO2. The corrosion rate of Al/SiO2(T) was lower than that of Al/SiO2(B) composites.
{"title":"Mechanical Strength and Corrosion Rate of Aluminium Composites (Al/SiO2): Nanoparticle Silica (NPS) as Reinforcement","authors":"Munasir, Triwikantoro, M. Zainuri, R. Bäßler, Darminto","doi":"10.21315/JPS2019.30.1.7","DOIUrl":"https://doi.org/10.21315/JPS2019.30.1.7","url":null,"abstract":"The fabrication and characteristics of amorphous silica reinforced Al matrix composites are studied in this paper. The major starting materials were commercial Al powder and extracted nanoparticle SiO2 (NPS) powder from Indonesian silica sands. Two different active solutions,namely N-butanol and tetramethylammonium hydroxide (TMAH), were introduced during synthesis. Characterisations in terms of physical, mechanical, microstructural and corrosion rate examinations were also employed. Introducing the SiO2 nanoparticles into the Al matrix has decreased the density and increased the porosity of the composites. The addition of N-butanol into Al/SiO2(Al/SiO2(B)) led to broader and lower X-ray diffraction profiles than the addition of TMAH (Al/SiO2(T)). From the microstructural analysis, we found that the SiO2 particles enter and agglomerate into the opening gap of the Al sheets. Furthermore, yield strength, ultimate compression strength and modulus of elasticity tended to reduce the addition of SiO2. The corrosion rate of Al/SiO2(T) was lower than that of Al/SiO2(B) composites.","PeriodicalId":16757,"journal":{"name":"Journal of Physical Science","volume":"1 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2019-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82309481","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-05-15DOI: 10.21315/JPS2019.30.1.11
N. A. Mokri, Oh Pei Ching, H. Mukhtar, C. Leng
Mobil Composition of Matter no. 48 (MCM-48) is a promising inorganic particle due to its unique crystal structure and 3-dimensional porous network. Incorporating a discrete amount of nanosized MCM-48 for material development would give significant impact to the material’s performance and mechanical robustness. Thus far, the synthesis of MCM-48 in the nanoscale regime has been achieved via chemical modification techniques. However, they are often not reproducible due to limited understanding of surfactant behaviour. On the other hand, physical modification technique is more stable, thereby can reduce the possibility of producing other undesired mesophase. Nevertheless, this technique has not been adapted for nanosized MCM-48 synthesis. In this work, the physical modification technique was adapted to tailor MCM-48 particle size by varying stirring speed (i.e., 1000 rpm, 3000 rpm and 5000 rpm) and using different types of washing medium. Particle size distribution (PSD) studies showed mean particle size of 250 ± 50 nm. XRD analysis displayed several crystalline peaks indexed to cubic crystal mesophase. Transmission electron microscopy (TEM) and Brunauer-Emmett Teller (BET) analyses also showed a unique 3D cubic interconnecting porous network with specific surface area of 1030 m2 g–1. It was revealed that the degree of agglomeration increased as relative polarity of alcohol increased, CH3OH > CH3CH2OH. Therefore, particle size and agglomeration state of MCM-48 can be tailored by varying the physical modification techniques while maintaining its intrinsic pore morphology.
{"title":"Tailoring Particle Size and Agglomeration State of Mesoporous MCM-48 via Optimisation of Sol-gel Silica Process","authors":"N. A. Mokri, Oh Pei Ching, H. Mukhtar, C. Leng","doi":"10.21315/JPS2019.30.1.11","DOIUrl":"https://doi.org/10.21315/JPS2019.30.1.11","url":null,"abstract":"Mobil Composition of Matter no. 48 (MCM-48) is a promising inorganic particle due to its unique crystal structure and 3-dimensional porous network. Incorporating a discrete amount of nanosized MCM-48 for material development would give significant impact to the material’s performance and mechanical robustness. Thus far, the synthesis of MCM-48 in the nanoscale regime has been achieved via chemical modification techniques. However, they are often not reproducible due to limited understanding of surfactant behaviour. On the other hand, physical modification technique is more stable, thereby can reduce the possibility of producing other undesired mesophase. Nevertheless, this technique has not been adapted for nanosized MCM-48 synthesis. In this work, the physical modification technique was adapted to tailor MCM-48 particle size by varying stirring speed (i.e., 1000 rpm, 3000 rpm and 5000 rpm) and using different types of washing medium. Particle size distribution (PSD) studies showed mean particle size of 250 ± 50 nm. XRD analysis displayed several crystalline peaks indexed to cubic crystal mesophase. Transmission electron microscopy (TEM) and Brunauer-Emmett Teller (BET) analyses also showed a unique 3D cubic interconnecting porous network with specific surface area of 1030 m2 g–1. It was revealed that the degree of agglomeration increased as relative polarity of alcohol increased, CH3OH > CH3CH2OH. Therefore, particle size and agglomeration state of MCM-48 can be tailored by varying the physical modification techniques while maintaining its intrinsic pore morphology.","PeriodicalId":16757,"journal":{"name":"Journal of Physical Science","volume":"91 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2019-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84420337","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}
M. J. Rashid, A. Mamun, Md. Samiul Islam Sadek, T. Hossain, S. Hasan
This study describes the characteristics of GaN/Al1-xGaxN quantum well (QW) operating in the UV region by varying different parameters. It is well known that the spontaneous and piezoelectric polarisations in wurtzite nitride heterostructures give rise to large built-in electric fields, which leads to an important consequence in the optical properties of GaN/Al1-xGaxN quantum wells. We first modelled the effect of electric field on the calculated electronic band structure. The increase in electric field affected the band structure for a fixed QW and barrier thickness. Then we investigated the effect of QW thickness on the bandgap energy for different electric fields. Afterwards, the Al composition (1-x) and Al1-xGaxN barrier thickness are varied for different well thickness with a fixed electric field.
{"title":"Simulation Study of GaN/Al1-xGaxN Quantum Well (QW) Operating in the UV Region","authors":"M. J. Rashid, A. Mamun, Md. Samiul Islam Sadek, T. Hossain, S. Hasan","doi":"10.21315/JPS2019.30.1.3","DOIUrl":"https://doi.org/10.21315/JPS2019.30.1.3","url":null,"abstract":"This study describes the characteristics of GaN/Al1-xGaxN quantum well (QW) operating in the UV region by varying different parameters. It is well known that the spontaneous and piezoelectric polarisations in wurtzite nitride heterostructures give rise to large built-in electric fields, which leads to an important consequence in the optical properties of GaN/Al1-xGaxN quantum wells. We first modelled the effect of electric field on the calculated electronic band structure. The increase in electric field affected the band structure for a fixed QW and barrier thickness. Then we investigated the effect of QW thickness on the bandgap energy for different electric fields. Afterwards, the Al composition (1-x) and Al1-xGaxN barrier thickness are varied for different well thickness with a fixed electric field.","PeriodicalId":16757,"journal":{"name":"Journal of Physical Science","volume":"1 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2019-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76856321","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-04-25DOI: 10.21315/JPS2019.30.1.10
Vicinisvarri Inderan, M. arafat, A. Haseeb, K. Sudesh, H. Lee
A comparative study of structural and ethanol gas sensing properties of pure, nickel and palladium doped SnO 2 nanorods synthesised by the hydrothermal method. J. Phys. Sci. , 30(1), 127–143, ABSTRACT: SnO 2 nanostructures are usually modified with some metal dopants in order to improve its gas sensing properties. In this work, pure tin oxide (SnO 2 ), nickel (Ni) doped SnO 2 (Ni:SnO 2 ) and palladium (Pd) doped SnO 2 (Pd:SnO 2 ) nanorods were successfully synthesised via hydrothermal method at low temperature (180°C) without templates or further calcination. All the samples were systematically analysed using X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FESEM) and high resolution transmission electron microscopy (HRTEM). The sensor response (R = R 0 /R g ) towards 1000 ppm ethanol gas was investigated using nitrogen gas as a carrier gas. XRD results confirmed that all samples consisted of rutile tetragonal-shaped SnO 2 . It was found that the average diameter of nanorods formed in Ni:SnO 2 and Pd:SnO 2 were decreased to ~6 nm and ~10 nm, compared with nanorods formed in pure SnO 2 (~25 nm). The gas sensing results indicated that the sensor properties of SnO 2 were enhanced after the doping process. At 450°C, the Pd:SnO 2 nanorod sensor recorded the highest response value towards 1000 ppm ethanol gas which is 15 times higher than pure SnO 2 nanorods. Interestingly, all samples showed similar response time, ~ 40 s. However, pure SnO 2 and Ni:SnO 2 nanorods sensors exhibited longer recovery time compared to Pd:SnO 2 nanorods. Pd:SnO 2 nanorods recorded only 12 min of almost 100% recovery. It is proposed that Pd:SnO 2 sensor could be a promising candidate for the detection of ethanol gas.
{"title":"A Comparative Study of Structural and Ethanol Gas Sensing Properties of Pure, Nickel and Palladium Doped SnO2 Nanorods Synthesised by the Hydrothermal Method","authors":"Vicinisvarri Inderan, M. arafat, A. Haseeb, K. Sudesh, H. Lee","doi":"10.21315/JPS2019.30.1.10","DOIUrl":"https://doi.org/10.21315/JPS2019.30.1.10","url":null,"abstract":"A comparative study of structural and ethanol gas sensing properties of pure, nickel and palladium doped SnO 2 nanorods synthesised by the hydrothermal method. J. Phys. Sci. , 30(1), 127–143, ABSTRACT: SnO 2 nanostructures are usually modified with some metal dopants in order to improve its gas sensing properties. In this work, pure tin oxide (SnO 2 ), nickel (Ni) doped SnO 2 (Ni:SnO 2 ) and palladium (Pd) doped SnO 2 (Pd:SnO 2 ) nanorods were successfully synthesised via hydrothermal method at low temperature (180°C) without templates or further calcination. All the samples were systematically analysed using X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FESEM) and high resolution transmission electron microscopy (HRTEM). The sensor response (R = R 0 /R g ) towards 1000 ppm ethanol gas was investigated using nitrogen gas as a carrier gas. XRD results confirmed that all samples consisted of rutile tetragonal-shaped SnO 2 . It was found that the average diameter of nanorods formed in Ni:SnO 2 and Pd:SnO 2 were decreased to ~6 nm and ~10 nm, compared with nanorods formed in pure SnO 2 (~25 nm). The gas sensing results indicated that the sensor properties of SnO 2 were enhanced after the doping process. At 450°C, the Pd:SnO 2 nanorod sensor recorded the highest response value towards 1000 ppm ethanol gas which is 15 times higher than pure SnO 2 nanorods. Interestingly, all samples showed similar response time, ~ 40 s. However, pure SnO 2 and Ni:SnO 2 nanorods sensors exhibited longer recovery time compared to Pd:SnO 2 nanorods. Pd:SnO 2 nanorods recorded only 12 min of almost 100% recovery. It is proposed that Pd:SnO 2 sensor could be a promising candidate for the detection of ethanol gas.","PeriodicalId":16757,"journal":{"name":"Journal of Physical Science","volume":"81 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2019-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82202250","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-02-15DOI: 10.21315/JPS2019.30.S1.5
N. F. Zaaba, H. Ismail
Plastics have many benefits due to their light weight, cost effectiveness, durability and other advantages. They are used as agricultural films, packaging, disposal consumer items, health, construction, etc. However, most plastics are not degradable which cause serious environmental problem. Addition of natural fillers into thermoplastics not only reduce the cost of the thermoplastic/natural filler composites but also help in reducing the waste of non-degradable plastic composite materials in the environment. Present short review deals with the issue of non-degradable plastic materials and the application of various natural fillers in thermoplastic composites. The chemical modifications including compatibilisation and radiation are reviewed and discussed.
{"title":"Thermoplastic/Natural Filler Composites: A Short Review","authors":"N. F. Zaaba, H. Ismail","doi":"10.21315/JPS2019.30.S1.5","DOIUrl":"https://doi.org/10.21315/JPS2019.30.S1.5","url":null,"abstract":"Plastics have many benefits due to their light weight, cost effectiveness, durability and other advantages. They are used as agricultural films, packaging, disposal consumer items, health, construction, etc. However, most plastics are not degradable which cause serious environmental problem. Addition of natural fillers into thermoplastics not only reduce the cost of the thermoplastic/natural filler composites but also help in reducing the waste of non-degradable plastic composite materials in the environment. Present short review deals with the issue of non-degradable plastic materials and the application of various natural fillers in thermoplastic composites. The chemical modifications including compatibilisation and radiation are reviewed and discussed.","PeriodicalId":16757,"journal":{"name":"Journal of Physical Science","volume":"39 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2019-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90637041","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-02-15DOI: 10.21315/JPS2019.30.S1.6
M. H. Abdul Kudus, H. Md. Akil, M. R. Zakaria, M. B. H. Othman
: Carbon nanotubes (CNT) and graphene nanoparticles (GNP) have been used as carbonaceous filler in epoxy composites based on the diglycidyl ether of bisphenol A (DGEBA) cured with tetra methyl diamine (TMD). Both CNT/epoxy and GNP/epoxy nanocomposites were subjected to ageing at 0%, 30%, 50%, 70% and 100% of relative humidity at room temperature for three weeks. Both composites show increasing water absorption percentage at higher relative humidity. Moreover, the GNP/epoxy nanocomposites showed a higher water absorption compared to CNT/epoxy nanocomposites. The dielectric constant increment of both nanocomposites is parallel to the water absorption properties. It is concluded that water absorption leads both to increase the dielectric constant of the epoxy resin.
{"title":"Effect of Water Absorption on Dielectric Constant of TMD Cured of Carbonaceous Filled Epoxy Composites","authors":"M. H. Abdul Kudus, H. Md. Akil, M. R. Zakaria, M. B. H. Othman","doi":"10.21315/JPS2019.30.S1.6","DOIUrl":"https://doi.org/10.21315/JPS2019.30.S1.6","url":null,"abstract":": Carbon nanotubes (CNT) and graphene nanoparticles (GNP) have been used as carbonaceous filler in epoxy composites based on the diglycidyl ether of bisphenol A (DGEBA) cured with tetra methyl diamine (TMD). Both CNT/epoxy and GNP/epoxy nanocomposites were subjected to ageing at 0%, 30%, 50%, 70% and 100% of relative humidity at room temperature for three weeks. Both composites show increasing water absorption percentage at higher relative humidity. Moreover, the GNP/epoxy nanocomposites showed a higher water absorption compared to CNT/epoxy nanocomposites. The dielectric constant increment of both nanocomposites is parallel to the water absorption properties. It is concluded that water absorption leads both to increase the dielectric constant of the epoxy resin.","PeriodicalId":16757,"journal":{"name":"Journal of Physical Science","volume":"23 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2019-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88521594","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-02-15DOI: 10.21315/JPS2019.30.S1.9
Raihana Bahru, A. Mohamed
Thermal interface materials (TIM) involve heat removal from electronic devices. It is used to remove heat sink from the heat sources to prolong the operation system of a device. It normally replaces the thermally insulated air between the two surfaces and uses it as a secondary thermal conductive material. The current thermal conductivity of TIM is considered to be a limitation for the development of advance electronic devices. In this study, the performance of carbon nanotubes (CNTs) which were used as TIM was investigated by using electrophoretic deposition method. The deposition of CNTs was varied from one to six layers and the performance of deposition was evaluated. The stable suspension of CNTs in DMF with zeta potential reading of –35.87 mV give rise to a smooth and uniform deposition on nickel plated copper substrate (heat spreader) with the usage of electrophoretic deposition (EPD). Maximum layers of CNTs deposition were obtained at six layers with 56.95 μm of deposition thickness and 11.0 mg of deposition weight. Thermal conductivity was measured using a thermal analyser while the thickness of deposition was observed using scanning electron microscope (SEM). The employment of CNTs improved the heat removal of TIM with thermal conductivity reading of 27.08 W m–1 K–1. Optimisation studies revealed that EPD operated at an applied voltage of 175 V coupled with 10 min deposition time produced a single layer deposition with the thickness of 14.14 μm.
热界面材料(TIM)涉及电子设备的散热。用于从热源中取出散热片，延长设备的运行时间。它通常取代两个表面之间的隔热空气，并将其用作二次导热材料。目前，TIM的热导率被认为是限制先进电子器件发展的一个因素。本研究采用电泳沉积法研究了碳纳米管(CNTs)作为TIM材料的性能。CNTs的沉积层从1层到6层不等，并对沉积性能进行了评价。在zeta电位读数为-35.87 mV的DMF中，CNTs稳定悬浮，电泳沉积(EPD)在镀镍铜衬底(散热器)上形成光滑均匀的沉积。在沉积厚度为56.95 μm、沉积重量为11.0 mg的6层中，CNTs沉积层数最多。用热分析仪测量热导率，用扫描电镜(SEM)观察沉积厚度。CNTs的使用提高了TIM的热导率，其导热系数为27.08 W m-1 K-1。优化研究表明，在175 V的外加电压和10 min的沉积时间下，EPD可以获得厚度为14.14 μm的单层沉积。
{"title":"Effect of Carbon Nanotubes as Thermal Interface Materials on Thermal Conductivity Using Electrophoretic Deposition","authors":"Raihana Bahru, A. Mohamed","doi":"10.21315/JPS2019.30.S1.9","DOIUrl":"https://doi.org/10.21315/JPS2019.30.S1.9","url":null,"abstract":"Thermal interface materials (TIM) involve heat removal from electronic devices. It is used to remove heat sink from the heat sources to prolong the operation system of a device. It normally replaces the thermally insulated air between the two surfaces and uses it as a secondary thermal conductive material. The current thermal conductivity of TIM is considered to be a limitation for the development of advance electronic devices. In this study, the performance of carbon nanotubes (CNTs) which were used as TIM was investigated by using electrophoretic deposition method. The deposition of CNTs was varied from one to six layers and the performance of deposition was evaluated. The stable suspension of CNTs in DMF with zeta potential reading of –35.87 mV give rise to a smooth and uniform deposition on nickel plated copper substrate (heat spreader) with the usage of electrophoretic deposition (EPD). Maximum layers of CNTs deposition were obtained at six layers with 56.95 μm of deposition thickness and 11.0 mg of deposition weight. Thermal conductivity was measured using a thermal analyser while the thickness of deposition was observed using scanning electron microscope (SEM). The employment of CNTs improved the heat removal of TIM with thermal conductivity reading of 27.08 W m–1 K–1. Optimisation studies revealed that EPD operated at an applied voltage of 175 V coupled with 10 min deposition time produced a single layer deposition with the thickness of 14.14 μm.","PeriodicalId":16757,"journal":{"name":"Journal of Physical Science","volume":"31 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2019-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80966012","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-02-15DOI: 10.21315/JPS2019.30.S1.7
N. Mamat, M. Jaafar, Z. Hamid
Polylactic acid (PLA) microsphere as a drug carrier has been extensively investigated for drug delivery systems. However, due to its limitation of surface hydrophobicity, surface modifications have been studied to improve its utilisation in tissue engineering applications. In the present study, PLA microsphere loaded with gentamicin (GENMS) was modified to enhance its hydrophilicity by surface treatment with additional of ethanol. Ethanol was applied as a co-treating medium in alkaline hydrolysis of NaOH to assist the hydroxide nucleophilic attack on the ester bond of PLA. Alkaline concentrations of NaOH and NaOH/ethanol was set at 0.15 M, 0.25 M and 0.35 M. After surface treatment, hydrophilicity of GENMS surface were improved significantly whereby contact angle reduced for about 23.1% and 26.8% for modification using NaOH and NaOH/ethanol, respectively, compared with the neat GENMS. Obvious surface roughness presented by NaOH/ethanol modification improved hydrophilicity of GENMS. As a result, protein adsorption on the GENMS surface treated by NaOH/ethanol were reduced than NaOH modification. Moreover, the highest encapsulation efficiency by NaOH/ethanol modification provided an advantage of co-treating by ethanol and has a greater drug release compared with NaOH modification.
{"title":"Surface Modification of Gentamicin-loaded Polylactic Acid (PLA) Microsphere Using Double Emulsion and Solvent Evaporation: Effect on Protein Adsorption and Drug Release Behaviour","authors":"N. Mamat, M. Jaafar, Z. Hamid","doi":"10.21315/JPS2019.30.S1.7","DOIUrl":"https://doi.org/10.21315/JPS2019.30.S1.7","url":null,"abstract":"Polylactic acid (PLA) microsphere as a drug carrier has been extensively investigated for drug delivery systems. However, due to its limitation of surface hydrophobicity, surface modifications have been studied to improve its utilisation in tissue engineering applications. In the present study, PLA microsphere loaded with gentamicin (GENMS) was modified to enhance its hydrophilicity by surface treatment with additional of ethanol. Ethanol was applied as a co-treating medium in alkaline hydrolysis of NaOH to assist the hydroxide nucleophilic attack on the ester bond of PLA. Alkaline concentrations of NaOH and NaOH/ethanol was set at 0.15 M, 0.25 M and 0.35 M. After surface treatment, hydrophilicity of GENMS surface were improved significantly whereby contact angle reduced for about 23.1% and 26.8% for modification using NaOH and NaOH/ethanol, respectively, compared with the neat GENMS. Obvious surface roughness presented by NaOH/ethanol modification improved hydrophilicity of GENMS. As a result, protein adsorption on the GENMS surface treated by NaOH/ethanol were reduced than NaOH modification. Moreover, the highest encapsulation efficiency by NaOH/ethanol modification provided an advantage of co-treating by ethanol and has a greater drug release compared with NaOH modification.","PeriodicalId":16757,"journal":{"name":"Journal of Physical Science","volume":"125 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2019-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84954614","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-02-15DOI: 10.21315/JPS2019.30.S1.8
Dina Liyana Mohamed Roshidin Murad, Mohd Shamsul Mohd Nasir, L. Law, I. Idris, M. Othman, M. Malaysia
Flared gas emission control from an oil production platform. Phys. Sci. , 30(Supp. 1), 125–147, ABSTRACT: In Samarang oil platform of Repsol (Talisman) Malaysia Limited, there is a need to increase its current oil production that would result in an increase of the associated/excess gas from 21 mmscfd to 31 mmscfd. The current low-pressure gas system on the platform is designed to accommodate up to 21 mmscfd of gas. The excess produced gas of 10 mmscfd, if not re-injected back into the reservoir, shall need to be flared on a daily basis in order to maximise the oil production rate. This gas flaring expends large amounts of energy and causes environmental degradation and potential health risk. There are four practical cases being considered in this unprecedented effort to control the flared gas and its resulting emissions from the industrially practical standpoint. Three cases use the existing compressor and varying compressor suction pressure between 5 barg and 6 barg with total compressors power is limited up to 2280 kW. The flared gas emission for these cases ranges from 7 mmscfd to 1 mmscfd, which is lower than the expected flowrate of 10 mmscfd. In the case where a new compressor is installed, a zero flared rate is achieved.
石油生产平台燃烧气体排放控制。理论物理。科学。, 30(增刊。摘要:在Repsol (Talisman) Malaysia Limited的Samarang石油平台，需要增加其当前的石油产量，这将导致伴生/过剩天然气从2100万立方英尺/天增加到31万立方英尺/天。目前平台上的低压气体系统设计为可容纳高达21 mmscfd的气体。如果不将多余的10百万立方英尺/天的产出气体重新注入储层，则需要每天进行燃烧，以最大限度地提高石油产量。这种气体燃烧消耗大量能源，造成环境退化和潜在的健康风险。从工业实践的角度来看，在这一史无前例的控制燃烧气体及其产生的排放的努力中，有四个实际情况正在考虑之中。三种情况下，使用现有的压缩机和在5barg和6barg之间变化的压缩机吸入压力，压缩机总功率限制在2280 kW。在这些情况下，燃烧气体排放量在7至1 mmscfd之间，低于10 mmscfd的预期流量。在安装新压缩机的情况下，可以实现零膨胀率。
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