S. Saleh, Ghani Wan Azlina Wan Ab Karim, K. L. Soh
: The coal bottom ash (CBA) sourced from thermal power plant was chemically treated using hydrochloric acid (HCl), namely CBA-HCl, and used as an adsorbent for palm oil mill effluent (POME) decolourisation. The treated CBA-HCl was characterised for surface property via Brunauer-Emmett-Teller (BET), surface chemistry via Fourier transform infrared (FTIR) and surface morphology via scanning electron microscopy (SEM). Its effectiveness for adsorption of POME colour was investigated via batch experiments as a function of pH, initial POME concentration, adsorbent dosage and contact time. The adsorption increased with increasing contact time until an equilibrium state was achieved within 18 h to 24 h. The maximum POME colour removal, 81.15% was achieved at pH 6 utilising 14% (w/v) adsorbent dosage for 24 h. The colour adsorption isotherm and kinetics of the CBA-HCl was well-fitted with Freundlich and pseudo-second order models with correlation coefficient, R 2 = 0.9991 and R 2 = 0.9996, respectively. Based on the results, CBA can be a potential adsorbent in removing POME colour before being discharged into a watercourse.
{"title":"Treated Coal Bottom Ash for Palm Oil Mill Effluent (POME) Decolourisation","authors":"S. Saleh, Ghani Wan Azlina Wan Ab Karim, K. L. Soh","doi":"10.21315/jps2019.30.3.7","DOIUrl":"https://doi.org/10.21315/jps2019.30.3.7","url":null,"abstract":": The coal bottom ash (CBA) sourced from thermal power plant was chemically treated using hydrochloric acid (HCl), namely CBA-HCl, and used as an adsorbent for palm oil mill effluent (POME) decolourisation. The treated CBA-HCl was characterised for surface property via Brunauer-Emmett-Teller (BET), surface chemistry via Fourier transform infrared (FTIR) and surface morphology via scanning electron microscopy (SEM). Its effectiveness for adsorption of POME colour was investigated via batch experiments as a function of pH, initial POME concentration, adsorbent dosage and contact time. The adsorption increased with increasing contact time until an equilibrium state was achieved within 18 h to 24 h. The maximum POME colour removal, 81.15% was achieved at pH 6 utilising 14% (w/v) adsorbent dosage for 24 h. The colour adsorption isotherm and kinetics of the CBA-HCl was well-fitted with Freundlich and pseudo-second order models with correlation coefficient, R 2 = 0.9991 and R 2 = 0.9996, respectively. Based on the results, CBA can be a potential adsorbent in removing POME colour before being discharged into a watercourse.","PeriodicalId":16757,"journal":{"name":"Journal of Physical Science","volume":"1 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2019-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89615083","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 : 2019-09-15DOI: 10.21315/jps2019.30.2.11
Nurul Fatihah Nik Sin, K. Ibrahim, N. Zainal
Growing interest in homoepitaxial growth of nitride-based devices has driven considerable efforts towards producing bulk gallium nitride single crystal as a substrate for the devices. Therefore, the process of producing the bulk gallium nitride crystal substrate should be simple and yet cost-effective to reduce the production cost of the devices. To date, several methods of growing bulk gallium nitride crystal have been proposed. Sodium flux method is one of the most promising ways since it requires a moderate growth temperature and growth pressure, as well as being simple and costeffective. This paper will briefly review the progress made to advance the growth of bulk gallium nitride single crystal by sodium flux method, including discussing challenges and proposing possible improvements in future.
{"title":"Growth of Bulk Gallium Nitride Single Crystal by Sodium Flux Method: A Brief\u0000 Review","authors":"Nurul Fatihah Nik Sin, K. Ibrahim, N. Zainal","doi":"10.21315/jps2019.30.2.11","DOIUrl":"https://doi.org/10.21315/jps2019.30.2.11","url":null,"abstract":"Growing interest in homoepitaxial growth of nitride-based devices has driven considerable efforts towards producing bulk gallium nitride single crystal as a substrate for the devices. Therefore, the process of producing the bulk gallium nitride crystal substrate should be simple and yet cost-effective to reduce the production cost of the devices. To date, several methods of growing bulk gallium nitride crystal have been proposed. Sodium flux method is one of the most promising ways since it requires a moderate growth temperature and growth pressure, as well as being simple and costeffective. This paper will briefly review the progress made to advance the growth of bulk gallium nitride single crystal by sodium flux method, including discussing challenges and proposing possible improvements in future.","PeriodicalId":16757,"journal":{"name":"Journal of Physical Science","volume":"15 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2019-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80861494","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}
Pradnya Kosbe, P. Patil, M. Manickam, Gurunathan Ramamurthy, India Rane Brake Lining Ltd.
A suitable selection of a filler material enhances the mechanical and tribological characteristics of brake friction material. There are various types of fillers like organic, inorganic, metallic and natural fibres. Among these various types, metallic fillers are very important as they consist of different functional characteristics of brake friction material. Hence in this work, four friction composites are shown with identical parent composition (65 wt%) and varying steel powder from 0 wt% to 12 wt%, and barite from 35 wt% to 23 wt%, respectively in each composition, i.e., S0, S1, S2 and S3. All these four composites are characterised for physical and mechanical properties according to Indian Standards (IS). The coefficient of friction is investigated using a pin on disc tribometer. Finally, the correlation between physical properties and coefficient of friction is determined. It is concluded that inclusion of steel powder improved almost all the physical and mechanical properties. It is also observed that density, void content and hardness influence the coefficient of friction level.
{"title":"Experimental Investigation of Physical and Mechanical Properties of Steel Powder\u0000 Filled Disc Brake Friction Materials","authors":"Pradnya Kosbe, P. Patil, M. Manickam, Gurunathan Ramamurthy, India Rane Brake Lining Ltd.","doi":"10.21315/jps2019.30.2.6","DOIUrl":"https://doi.org/10.21315/jps2019.30.2.6","url":null,"abstract":"A suitable selection of a filler material enhances the mechanical and tribological characteristics of brake friction material. There are various types of fillers like organic, inorganic, metallic and natural fibres. Among these various types, metallic fillers are very important as they consist of different functional characteristics of brake friction material. Hence in this work, four friction composites are shown with identical parent composition (65 wt%) and varying steel powder from 0 wt% to 12 wt%, and barite from 35 wt% to 23 wt%, respectively in each composition, i.e., S0, S1, S2 and S3. All these four composites are characterised for physical and mechanical properties according to Indian Standards (IS). The coefficient of friction is investigated using a pin on disc tribometer. Finally, the correlation between physical properties and coefficient of friction is determined. It is concluded that inclusion of steel powder improved almost all the physical and mechanical properties. It is also observed that density, void content and hardness influence the coefficient of friction level.","PeriodicalId":16757,"journal":{"name":"Journal of Physical Science","volume":"27 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2019-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78648014","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}
Nur Fatin Silmi Mohd Azani, Caryn Tan Hui Chuin, N. Abdullah, S. Sharifuddin, M. Hussin
The aim of this research is to investigate and identify the absorption capacity of activated carbon derived from a rubber seed shell (RSS). An RSS was prepared through the conduction of a chemical activation process primarily using potassium hydroxide at a ratio of 1:1 followed by carbonisation at 400°C with N2 under a steady flow rate of 1 ml min–1 for 3 h. The produced RSS activated carbon (RSSAC) was characterised using Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopyenergy dispersive X-ray (SEM-EDX) spectroscopy, Brunauer-Emmet-Teller (BET) analysis and thermogravimetric analysis (TGA). The SEM image obtained revealed the presence of a highly porous RSSAC surface, with an average pore diameter of 3.35 nm, indicating a mesoporous structure. EDX analysis depicted that C and K were major elements found in RSSAC with a compound percentage of 99.73% and 0.27%, respectively. Batch adsorption studies were conducted to investigate the adsorption properties of RSSAC towards the removal of methylene blue (MB) dye. The optimum dosage of RSSAC was determined to be 5.0 g per 100 ml. Effect of contact time revealed that the highest percentage removal of MB (99.62%) by RSSAC was obtained at a concentration of 100 mg l–1 during a time period of 1 h. In comparison, the effect of pH study affirmed that RSSAC achieved an average removal of 99% of MB in both acidic and basic media at 100 mg l–1. Kinetic studies revealed that the adsorption process abides by the pseudosecond-order kinetic model. Based on the findings by utilising multiple approaches Activated Carbon from Rubber Seed 2 as mentioned, it can be proposed that RSSAC is a viable alternative to act as a green alternative adsorbent.
本研究的目的是研究和鉴定橡胶种子壳(RSS)活性炭的吸附能力。以氢氧化钾为主要原料，以1:1的比例通过化学活化过程制备RSS，然后在400°C用N2在1 ml min-1的稳定流速下碳化3小时。所制备的RSS活性炭(RSSAC)使用傅里叶变换红外(FTIR)光谱、扫描电子显微镜、能量色散x射线(SEM-EDX)光谱、brunauer - emet - teller (BET)分析和热重分析(TGA)进行表征。SEM图像显示，RSSAC表面存在高孔结构，平均孔径为3.35 nm，为中孔结构。EDX分析显示，C和K是RSSAC的主要元素，复合比例分别为99.73%和0.27%。采用批吸附法研究了RSSAC对亚甲基蓝染料的吸附性能。RSSAC的最佳投加量为5.0 g / 100 ml。接触时间的影响表明，在100 mg - 1的浓度下，RSSAC对MB的去除率最高(99.62%)，时间为1 h。相比之下，pH的影响研究证实，在100 mg - 1的酸性和碱性培养基中，RSSAC对MB的平均去除率为99%。动力学研究表明，吸附过程符合准二级动力学模型。基于上述多种方法对橡胶籽2活性炭的研究结果，可以提出RSSAC是一种可行的绿色替代吸附剂。
{"title":"Characterisation and Kinetic Studies on Activated Carbon Derived from Rubber Seed\u0000 Shell for the Removal of Methylene Blue in Aqueous Solutions","authors":"Nur Fatin Silmi Mohd Azani, Caryn Tan Hui Chuin, N. Abdullah, S. Sharifuddin, M. Hussin","doi":"10.21315/jps2019.30.2.1","DOIUrl":"https://doi.org/10.21315/jps2019.30.2.1","url":null,"abstract":"The aim of this research is to investigate and identify the absorption capacity of activated carbon derived from a rubber seed shell (RSS). An RSS was prepared through the conduction of a chemical activation process primarily using potassium hydroxide at a ratio of 1:1 followed by carbonisation at 400°C with N2 under a steady flow rate of 1 ml min–1 for 3 h. The produced RSS activated carbon (RSSAC) was characterised using Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopyenergy dispersive X-ray (SEM-EDX) spectroscopy, Brunauer-Emmet-Teller (BET) analysis and thermogravimetric analysis (TGA). The SEM image obtained revealed the presence of a highly porous RSSAC surface, with an average pore diameter of 3.35 nm, indicating a mesoporous structure. EDX analysis depicted that C and K were major elements found in RSSAC with a compound percentage of 99.73% and 0.27%, respectively. Batch adsorption studies were conducted to investigate the adsorption properties of RSSAC towards the removal of methylene blue (MB) dye. The optimum dosage of RSSAC was determined to be 5.0 g per 100 ml. Effect of contact time revealed that the highest percentage removal of MB (99.62%) by RSSAC was obtained at a concentration of 100 mg l–1 during a time period of 1 h. In comparison, the effect of pH study affirmed that RSSAC achieved an average removal of 99% of MB in both acidic and basic media at 100 mg l–1. Kinetic studies revealed that the adsorption process abides by the pseudosecond-order kinetic model. Based on the findings by utilising multiple approaches Activated Carbon from Rubber Seed 2 as mentioned, it can be proposed that RSSAC is a viable alternative to act as a green alternative adsorbent.","PeriodicalId":16757,"journal":{"name":"Journal of Physical Science","volume":"95 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2019-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76855657","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}
First-principles electronic structure calculations were employed for the electronic, magnetic and structural properties of rutile CrO2. This material is a ferromagnetic half-metal with a semiconducting gap of 1.85 eV. The sharing of a single electron by Cr-3dyz and dxz orbitals is responsible for the metallic behaviour of CrO2 for the majority spin channel. For the application of on-site Coulomb interaction U up to 4 eV, the electrons in the valence band polarise towards the Fermi level (EF), while the electrons in the conduction band polarise away from EF. The enhanced shifting of conduction bands of the spin minority channel is responsible for the augmentation of the semiconducting spin gap. This system undergoes a metal-insulator transition (MIT) upon the application of U = 5 eV. Due to the presence of electron correlation, the electron in the dxy orbital shifts well below EF, while bonding components of dyz and dxz orbitals are occupied by the remaining single electron. Nevertheless, anti-bonding components of these two states remain unoccupied. Consequently, a band gap of Eg ~ 0.2 eV is opened near EF. The double exchange interactions between the partially occupied Cr-t2g states and p-d hybridisations are responsible for the ferromagnetic behaviour of CrO2 in both halfmetallic and insulating phases.
{"title":"First-principles Electronic Study of Metal-insulator Transition in the Rutile CrO2\u0000 at Room Temperature","authors":"S. Biswas","doi":"10.21315/jps2019.30.2.2","DOIUrl":"https://doi.org/10.21315/jps2019.30.2.2","url":null,"abstract":"First-principles electronic structure calculations were employed for the electronic, magnetic and structural properties of rutile CrO2. This material is a ferromagnetic half-metal with a semiconducting gap of 1.85 eV. The sharing of a single electron by Cr-3dyz and dxz orbitals is responsible for the metallic behaviour of CrO2 for the majority spin channel. For the application of on-site Coulomb interaction U up to 4 eV, the electrons in the valence band polarise towards the Fermi level (EF), while the electrons in the conduction band polarise away from EF. The enhanced shifting of conduction bands of the spin minority channel is responsible for the augmentation of the semiconducting spin gap. This system undergoes a metal-insulator transition (MIT) upon the application of U = 5 eV. Due to the presence of electron correlation, the electron in the dxy orbital shifts well below EF, while bonding components of dyz and dxz orbitals are occupied by the remaining single electron. Nevertheless, anti-bonding components of these two states remain unoccupied. Consequently, a band gap of Eg ~ 0.2 eV is opened near EF. The double exchange interactions between the partially occupied Cr-t2g states and p-d hybridisations are responsible for the ferromagnetic behaviour of CrO2 in both halfmetallic and insulating phases.","PeriodicalId":16757,"journal":{"name":"Journal of Physical Science","volume":"40 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2019-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91209358","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 : 2019-09-15DOI: 10.21315/jps2019.30.2.10
N. Petchwattana, W. Channuan, P. Naknaen, B. Narupai
This study aims to produce the poly(lactic acid) (PLA)/teak wood composite filament for 3D printing application. Prior to the production of the wood plastic composite (WPC) filaments, PLA was modified to remedy the problem of brittleness and low-melt viscosity by core-shell rubber (CSR) particles and acrylic processing aid (APA). Two different particle sizes of teak wood flour (WF) were added to the modified-PLA (mPLA). Silane coupling agent was further added to improve the interfacial adhesion between the hydrophilic WF and hydrophobic mPLA matrix. Experimental results indicated that all formulations could be fabricated as 3D printing filaments. However, the filaments were successfully printed only for the mPLA with 74 μm WF. For 125 μm, the printer nozzle was clogged up with the agglomerated WF. WPC filaments had higher water uptake than those mPLA and neat PLA, but it significantly decreased with the silane compatibilisation. SEM result also confirmed the improvement of the interfacial bonding between mPLA and WF, which facilitated better fibre-matrix stress transfer and improved the overall mechanical strength.
{"title":"3D Printing Filaments Prepared from Modified Poly(Lactic Acid)/Teak Wood Flour\u0000 Composites: An Investigation on the Particle Size Effects and Silane Coupling Agent\u0000 Compatibilisation","authors":"N. Petchwattana, W. Channuan, P. Naknaen, B. Narupai","doi":"10.21315/jps2019.30.2.10","DOIUrl":"https://doi.org/10.21315/jps2019.30.2.10","url":null,"abstract":"This study aims to produce the poly(lactic acid) (PLA)/teak wood composite filament for 3D printing application. Prior to the production of the wood plastic composite (WPC) filaments, PLA was modified to remedy the problem of brittleness and low-melt viscosity by core-shell rubber (CSR) particles and acrylic processing aid (APA). Two different particle sizes of teak wood flour (WF) were added to the modified-PLA (mPLA). Silane coupling agent was further added to improve the interfacial adhesion between the hydrophilic WF and hydrophobic mPLA matrix. Experimental results indicated that all formulations could be fabricated as 3D printing filaments. However, the filaments were successfully printed only for the mPLA with 74 μm WF. For 125 μm, the printer nozzle was clogged up with the agglomerated WF. WPC filaments had higher water uptake than those mPLA and neat PLA, but it significantly decreased with the silane compatibilisation. SEM result also confirmed the improvement of the interfacial bonding between mPLA and WF, which facilitated better fibre-matrix stress transfer and improved the overall mechanical strength.","PeriodicalId":16757,"journal":{"name":"Journal of Physical Science","volume":"16 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2019-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82170617","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Ridha, Nada Farhan Kadhim, Nadheer Jassim Mohammed
A significant correlation between the track density measured by CR-39 and the affluence has been found in the current study. This correlation can be used to calculate the expected track density in solid state nuclear track detector irradiated by any alpha source of known activity without using the detectors. Nine pieces of CR-39 were irradiated with alpha particles from Am-241 (10 μCi) point source for 0 s, 10 s, 20 s, 30 s, 40 s, 50 s, 60 s, 70 s and 80 s. The absorbance in UV-visible region (before and after etching of the detector) and in the energy band gap showed an acceptable correlation at 650 nm wavelength. This result leads to two semi-empirical equations: first equation between the track density and the absorbance; and second equation between the absorbance and the affluence. These findings can give the track density or the affluence by calculating the absorbance of the detector after etching without microscopic viewing and calibration.
{"title":"Correlation between the Track Density and Absorbance of Alpha Particles using CR-39\u0000 Detectors from UV-Visible Spectrum","authors":"A. Ridha, Nada Farhan Kadhim, Nadheer Jassim Mohammed","doi":"10.21315/jps2019.30.2.3","DOIUrl":"https://doi.org/10.21315/jps2019.30.2.3","url":null,"abstract":"A significant correlation between the track density measured by CR-39 and the affluence has been found in the current study. This correlation can be used to calculate the expected track density in solid state nuclear track detector irradiated by any alpha source of known activity without using the detectors. Nine pieces of CR-39 were irradiated with alpha particles from Am-241 (10 μCi) point source for 0 s, 10 s, 20 s, 30 s, 40 s, 50 s, 60 s, 70 s and 80 s. The absorbance in UV-visible region (before and after etching of the detector) and in the energy band gap showed an acceptable correlation at 650 nm wavelength. This result leads to two semi-empirical equations: first equation between the track density and the absorbance; and second equation between the absorbance and the affluence. These findings can give the track density or the affluence by calculating the absorbance of the detector after etching without microscopic viewing and calibration.","PeriodicalId":16757,"journal":{"name":"Journal of Physical Science","volume":"8 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2019-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80365160","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}
Activity concentrations were measured in phosphate fertilisers widely used in Saudi Arabia employing gamma ray spectrometry. The activity concentrations of 238U, 232Th and 40K were used to estimate the excess lifetime cancer risk (ELCR). The obtained data show that 238U and 40K concentrations are higher than the recommended values (35 Bq kg–1 and 400 Bq kg–1 for 238U and 40K, respectively) in most of phosphate fertilisers. The highest value of 238U was 4122 ± 82 Bq kg–1 for diammonium phosphate (DAP) fertiliser. Absorbed dose rate, annual effective dose rate and the ELCR were calculated. The results revealed that the values of outdoor, indoor and total ELCR values were higher than the world averages in all samples except one sample, sample of MAP fertiliser (monoammonium phosphate). The highest value of ELCRtot was for DAP fertiliser which is 50 times higher than the world average value (1.45 × 10–3). Moreover, the results indicated a strong correlation between uranium in phosphate fertilisers and ELCRtot. Based on the obtained results, the direct gamma radiation exposure from phosphate fertilisers is a serious radiological threat to the farmers.
{"title":"Evaluation of Excess Lifetime Cancer Risk Due to Gamma Rays Exposure from Phosphate\u0000 Fertilisers Used in Saudi Arabia","authors":"Fatimh Alshahri","doi":"10.21315/jps2019.30.2.5","DOIUrl":"https://doi.org/10.21315/jps2019.30.2.5","url":null,"abstract":"Activity concentrations were measured in phosphate fertilisers widely used in Saudi Arabia employing gamma ray spectrometry. The activity concentrations of 238U, 232Th and 40K were used to estimate the excess lifetime cancer risk (ELCR). The obtained data show that 238U and 40K concentrations are higher than the recommended values (35 Bq kg–1 and 400 Bq kg–1 for 238U and 40K, respectively) in most of phosphate fertilisers. The highest value of 238U was 4122 ± 82 Bq kg–1 for diammonium phosphate (DAP) fertiliser. Absorbed dose rate, annual effective dose rate and the ELCR were calculated. The results revealed that the values of outdoor, indoor and total ELCR values were higher than the world averages in all samples except one sample, sample of MAP fertiliser (monoammonium phosphate). The highest value of ELCRtot was for DAP fertiliser which is 50 times higher than the world average value (1.45 × 10–3). Moreover, the results indicated a strong correlation between uranium in phosphate fertilisers and ELCRtot. Based on the obtained results, the direct gamma radiation exposure from phosphate fertilisers is a serious radiological threat to the farmers.","PeriodicalId":16757,"journal":{"name":"Journal of Physical Science","volume":"1986 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2019-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90334595","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}
In this work, the feasibility of using guava leaves powder (GLP) as an adsorbent to remove ciprofloxacin (CIP) from aqueous solution was investigated. The effectiveness of GLP to remove CIP was studied under different experimental conditions. The optimum pH for the adsorption of CIP was found to be pH 4. The adsorption trend was rapid at the initial stage and equilibrium was achieved in 60 min. The percentage uptake of CIP decreased with increasing initial CIP concentration. The adsorption kinetics was found to conform well to the pseudo-second order kinetic model. Characterisation of GLP was carried out by using field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM) and Fourier-transform infrared (FTIR) spectrophotometry. Both Langmuir and Freundlich isotherm models were applied to describe the equilibrium adsorption data of CIP onto GLP. The maximum adsorption capacity (qm) was found to be 232.56 mg g–1. By applying Plackett-Burman design, contact time and pH were found to be the influential parameters in affecting the uptake of CIP onto GLP.
{"title":"Guava Leaves as Adsorbent for the Removal of Emerging Pollutant: Ciprofloxacin from\u0000 Aqueous Solution","authors":"Chin Tay, S. Ong","doi":"10.21315/jps2019.30.2.8","DOIUrl":"https://doi.org/10.21315/jps2019.30.2.8","url":null,"abstract":"In this work, the feasibility of using guava leaves powder (GLP) as an adsorbent to remove ciprofloxacin (CIP) from aqueous solution was investigated. The effectiveness of GLP to remove CIP was studied under different experimental conditions. The optimum pH for the adsorption of CIP was found to be pH 4. The adsorption trend was rapid at the initial stage and equilibrium was achieved in 60 min. The percentage uptake of CIP decreased with increasing initial CIP concentration. The adsorption kinetics was found to conform well to the pseudo-second order kinetic model. Characterisation of GLP was carried out by using field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM) and Fourier-transform infrared (FTIR) spectrophotometry. Both Langmuir and Freundlich isotherm models were applied to describe the equilibrium adsorption data of CIP onto GLP. The maximum adsorption capacity (qm) was found to be 232.56 mg g–1. By applying Plackett-Burman design, contact time and pH were found to be the influential parameters in affecting the uptake of CIP onto GLP.","PeriodicalId":16757,"journal":{"name":"Journal of Physical Science","volume":"6 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2019-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83027665","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 density, molar volume, apparent molar volume, viscosity and other parameters of Cu(II) surfactant derived from karanj oil in non-aqueous solvents of varying compositions have been determined at constant temperature 298.15 K. The results were used to determine the critical micelle concentration (CMC), soap-solvent interactions and the effect of chain length of the surface active molecule on various parameters. The CMC values of copper karanj soap solutions decreased with the increase in the concentration of polar solvent methanol in the solvent mixture. These studies were done to study the solution behaviour, micellar features and various interactions of the derived biologically active surfactant with polar and non-polar solvents to understand the applied part of the molecule. The apparent molar volume has been examined in terms of Masson equation, and the limiting apparent molar volume has been interpreted in terms of solute-solvent interaction. The detailed study of aforesaid compounds clearly indicates that the solutesolvent interaction decreases with the increase in ring strain and size of the synthesised complexes. The conclusions with regard to solute-solute and solute-solvent interaction have been discussed in terms of well-known Moulik’s and Jones-Dole equations. This vital information plays an important role in the selection of the synthesised molecule for various industrial and biological applications.
{"title":"Volumetric and Viscometric Studies of Copper Surfactant Derived from Karanj\u0000 (Pongamia pinnata) Oil in Methanol-benzene Mixture at 298.15 K","authors":"Shema Khan, Rashmi Sharma, A. Sharma","doi":"10.21315/jps2019.30.2.4","DOIUrl":"https://doi.org/10.21315/jps2019.30.2.4","url":null,"abstract":"The density, molar volume, apparent molar volume, viscosity and other parameters of Cu(II) surfactant derived from karanj oil in non-aqueous solvents of varying compositions have been determined at constant temperature 298.15 K. The results were used to determine the critical micelle concentration (CMC), soap-solvent interactions and the effect of chain length of the surface active molecule on various parameters. The CMC values of copper karanj soap solutions decreased with the increase in the concentration of polar solvent methanol in the solvent mixture. These studies were done to study the solution behaviour, micellar features and various interactions of the derived biologically active surfactant with polar and non-polar solvents to understand the applied part of the molecule. The apparent molar volume has been examined in terms of Masson equation, and the limiting apparent molar volume has been interpreted in terms of solute-solvent interaction. The detailed study of aforesaid compounds clearly indicates that the solutesolvent interaction decreases with the increase in ring strain and size of the synthesised complexes. The conclusions with regard to solute-solute and solute-solvent interaction have been discussed in terms of well-known Moulik’s and Jones-Dole equations. This vital information plays an important role in the selection of the synthesised molecule for various industrial and biological applications.","PeriodicalId":16757,"journal":{"name":"Journal of Physical Science","volume":"1 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2019-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89988083","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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