S. M. L. R. Samarakoon, M. Milani, L. Nayanajith, R. C. W. Arachchige, C. Abeyratne
Extruded biodegradable films based on Poly (butylene adipate-co-terephthalate) (PBAT) and Cassava starch (CS) at varying weights were prepared, and their relevant properties for packaging applications are here reported. Neither the peak position nor the intensity of the film’s distinctive infrared absorption peaks was altered by the addition of CS to PBAT. Therefore, adding CS to PBAT is solely a physical process. Experimental results show that the increase in CS content, the tensile strength, elongation at break, and the tear resistance of the composite are decreased. The "30% CS” included composite film was selected as the optimized composition since it is cost-effective while acquiring the required physical properties to be a better fit as a packaging material. However, the overall migration of residue on the surface of the “30% CS/PBAT” sample wasn’t in the acceptable range (<10 mg/dm2). Therefore, the developed product is suitable for use as a packaging material except for food packaging. Thus, the extrusion process needs to be further modified to be used as food packaging.
{"title":"Preparation and characterization of Cassava starch/Polybutylene (adipate-co-terephthalate) biodegradable composite film","authors":"S. M. L. R. Samarakoon, M. Milani, L. Nayanajith, R. C. W. Arachchige, C. Abeyratne","doi":"10.4038/sljp.v24i1.8124","DOIUrl":"https://doi.org/10.4038/sljp.v24i1.8124","url":null,"abstract":"Extruded biodegradable films based on Poly (butylene adipate-co-terephthalate) (PBAT) and Cassava starch (CS) at varying weights were prepared, and their relevant properties for packaging applications are here reported. Neither the peak position nor the intensity of the film’s distinctive infrared absorption peaks was altered by the addition of CS to PBAT. Therefore, adding CS to PBAT is solely a physical process. Experimental results show that the increase in CS content, the tensile strength, elongation at break, and the tear resistance of the composite are decreased. The \"30% CS” included composite film was selected as the optimized composition since it is cost-effective while acquiring the required physical properties to be a better fit as a packaging material. However, the overall migration of residue on the surface of the “30% CS/PBAT” sample wasn’t in the acceptable range (<10 mg/dm2). Therefore, the developed product is suitable for use as a packaging material except for food packaging. Thus, the extrusion process needs to be further modified to be used as food packaging.","PeriodicalId":21880,"journal":{"name":"Sri Lankan Journal of Physics","volume":"26 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82622994","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 presence of warm negative ion, propagation of ion-acoustic solitary waves has been investigated analytically in a plasma consisting of warm positive ion, warm positron and single-temperature non-isothermal electron. The necessary and sufficient conditions for the existence of compressive solitary waves are discussed critically along with the calculation of phase velocity, kinetic energy (K.E) and force (F) found out in this paper by this new analytical method. Some important general observations and Theorems related with this problem are highlighted that supports the results of previous authors. The Sagdeev potential function ψ(𝜙) [= - L(𝑢𝛼 )] against ϕ depicted graphically under the variation of different plasma parameters is the most important and interesting situations by this analytical method.
{"title":"Analytical study of ion-acoustic soliton in single temperature nonisothermal electron","authors":"S. Chattopadhyay","doi":"10.4038/sljp.v24i1.8129","DOIUrl":"https://doi.org/10.4038/sljp.v24i1.8129","url":null,"abstract":"In presence of warm negative ion, propagation of ion-acoustic solitary waves has been investigated analytically in a plasma consisting of warm positive ion, warm positron and single-temperature non-isothermal electron. The necessary and sufficient conditions for the existence of compressive solitary waves are discussed critically along with the calculation of phase velocity, kinetic energy (K.E) and force (F) found out in this paper by this new analytical method. Some important general observations and Theorems related with this problem are highlighted that supports the results of previous authors. The Sagdeev potential function ψ(𝜙) [= - L(𝑢𝛼 )] against ϕ depicted graphically under the variation of different plasma parameters is the most important and interesting situations by this analytical method.","PeriodicalId":21880,"journal":{"name":"Sri Lankan Journal of Physics","volume":"17 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75057704","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}
Wireless communications play a crucial role in human lives. The introduction of cellular network systems, broadband internet services and public Wi-Fi services increase the connectivity between people exponentially. These wireless networks require antenna structures to propagate carrier waves through space and these waves are located within the Radiofrequency (RF) region in the electromagnetic spectrum. The effects of these RF waves on people, especially children, and pregnant women cannot be neglected. According to the researchers, there are some adverse health issues related to thermal and non-thermal effects due to exposure to these non-ionizing radiations. In this study, RF exposure levels within the proximity of 21 selected kindergartens in the Colombo and Kandy districts were evaluated by using a high-frequency spectrum analyzer. Results of the study show a nearly 251% increase in the RF exposure levels in the kindergartens located in Colombo district relative to the kindergartens in Kandy district. As well as GSM900, GSM1800 and UMTS cellular communication bands show a higher contribution to background RF exposure than the other wireless networks. However, measured maximum electric fields and calculated specific absorption rate (SAR) values are well below the maximum permissible levels published by International Commission on Non-Ionizing Radiation Protection (ICNIRP).
{"title":"RF-EMR pollution levels near kindergartens due to mobile communication towers and Wi-Fi sources","authors":"S. Suraweera, K. Jayaratne","doi":"10.4038/sljp.v24i1.8117","DOIUrl":"https://doi.org/10.4038/sljp.v24i1.8117","url":null,"abstract":"Wireless communications play a crucial role in human lives. The introduction of cellular network systems, broadband internet services and public Wi-Fi services increase the connectivity between people exponentially. These wireless networks require antenna structures to propagate carrier waves through space and these waves are located within the Radiofrequency (RF) region in the electromagnetic spectrum. The effects of these RF waves on people, especially children, and pregnant women cannot be neglected. According to the researchers, there are some adverse health issues related to thermal and non-thermal effects due to exposure to these non-ionizing radiations. In this study, RF exposure levels within the proximity of 21 selected kindergartens in the Colombo and Kandy districts were evaluated by using a high-frequency spectrum analyzer. Results of the study show a nearly 251% increase in the RF exposure levels in the kindergartens located in Colombo district relative to the kindergartens in Kandy district. As well as GSM900, GSM1800 and UMTS cellular communication bands show a higher contribution to background RF exposure than the other wireless networks. However, measured maximum electric fields and calculated specific absorption rate (SAR) values are well below the maximum permissible levels published by International Commission on Non-Ionizing Radiation Protection (ICNIRP).","PeriodicalId":21880,"journal":{"name":"Sri Lankan Journal of Physics","volume":"18 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89209628","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. Abeykoon, R. D. De Silva, L. Nayanajith, I. Kottegoda
{"title":"A review on appropriate graphene synthesis methods for diverse applications","authors":"A. Abeykoon, R. D. De Silva, L. Nayanajith, I. Kottegoda","doi":"10.4038/sljp.v23i2.8116","DOIUrl":"https://doi.org/10.4038/sljp.v23i2.8116","url":null,"abstract":"","PeriodicalId":21880,"journal":{"name":"Sri Lankan Journal of Physics","volume":"28 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76801687","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}
{"title":"Studies on solitary waves in non-isothermal plasma","authors":"Sankar Chattopadhyay","doi":"10.4038/sljp.v23i2.8090","DOIUrl":"https://doi.org/10.4038/sljp.v23i2.8090","url":null,"abstract":"","PeriodicalId":21880,"journal":{"name":"Sri Lankan Journal of Physics","volume":"60 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75176062","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. E. Ibekwe, E. Inyang, J. B. Emah, A. O. Akpan, O. J. Yawo
{"title":"Mass spectra and thermal properties of deformed Schrödinger Equation for pseudoharmonic potential","authors":"E. E. Ibekwe, E. Inyang, J. B. Emah, A. O. Akpan, O. J. Yawo","doi":"10.4038/sljp.v23i2.8119","DOIUrl":"https://doi.org/10.4038/sljp.v23i2.8119","url":null,"abstract":"","PeriodicalId":21880,"journal":{"name":"Sri Lankan Journal of Physics","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74072233","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}
L. Nayanajith, R. D. De Silva, S. Rosa, I. Kottegoda
{"title":"Optimization of oxidation time of Kahatagaha vein graphite and reduction time of microwave assisted hydrothermal reduction of Kahatagaha graphene oxide","authors":"L. Nayanajith, R. D. De Silva, S. Rosa, I. Kottegoda","doi":"10.4038/sljp.v23i2.8125","DOIUrl":"https://doi.org/10.4038/sljp.v23i2.8125","url":null,"abstract":"","PeriodicalId":21880,"journal":{"name":"Sri Lankan Journal of Physics","volume":"17 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79638451","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}
{"title":"Study of structural and electronic properties of MnTiS2 compound","authors":"V. B. Parmar, A. Vora","doi":"10.4038/sljp.v23i1.8098","DOIUrl":"https://doi.org/10.4038/sljp.v23i1.8098","url":null,"abstract":"","PeriodicalId":21880,"journal":{"name":"Sri Lankan Journal of Physics","volume":"16 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75347927","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}
{"title":"Preliminary optimization of low-cost quasi solid-state dye sensitized solar cells with multilayer photoanodes, and graphite-based counter electrodes","authors":"H. Wickramasinghe, K. Wijayaratne, T. Bandara","doi":"10.4038/sljp.v23i1.8114","DOIUrl":"https://doi.org/10.4038/sljp.v23i1.8114","url":null,"abstract":"","PeriodicalId":21880,"journal":{"name":"Sri Lankan Journal of Physics","volume":"27 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81853809","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}
G. Wickramasinghe, V. Perera, R. Senthilnithy, C. N. Nupearachchi
{"title":"Comparison of ZnO nano particles synthesized using sodium hydroxide and triethylamine for photovoltaic applications","authors":"G. Wickramasinghe, V. Perera, R. Senthilnithy, C. N. Nupearachchi","doi":"10.4038/sljp.v23i1.8115","DOIUrl":"https://doi.org/10.4038/sljp.v23i1.8115","url":null,"abstract":"","PeriodicalId":21880,"journal":{"name":"Sri Lankan Journal of Physics","volume":"46 5 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76616293","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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