Pub Date : 2022-07-01DOI: 10.31357/vjs.v25i01.5919
Joseph F. S. Fernando
Rechargeable battery is the leading energy storage option for renewable power sources such as solar, wind and tidal (Park, et al., 2019, Tarascon, 2010). Furthermore, everyone owns a device powered by a rechargeable battery. Most of these devices are powered by lithium ion batteries (LIBs) owing to their rechargeability and high-energy density (Shin, et al., 2019). However, the rechargeable battery will lose its ability to retain a charge over time, forcing the consumer to discard the battery or product, which ends up in landfills. Owing to the high chemical activity of Li and the toxicity and flammability of organic solvent-based electrolytes, LIBs cause alarming safety and environmental issues (Yang, et al., 2018). Although Na+/K+ batteries are possible alternatives, these technologies also utilize organic electrolytes. Hence, there is a huge motivation to explore a battery chemistry that is long lasting, environmentally friendly, and cost-efficient. Rechargeable batteries based on water-based electrolytes are a revolutionary alternative and hold a prominent place in the energy storage research community. Along with other advantages, water also has a higher ionic conductivity (1 S cm-1) than organic electrolytes (~10-2 – 10-3 S cm-1) which is ideal for high rate cycling of batteries (Fang, et al., 2018, Winter, et al., 2004).The development of rechargeable aqueous batteries is ongoing, and there are systems based on monovalent ions (e.g. K+) and multivalent ions (e.g. Al3+, Zn2+ and Mg2+) (Liu, et al., 2014, Zhang, et al., 2017). Multivalent systems are more desirable given that their multiple redox states promise high specific capacity and energy density. Among multivalent systems, the rechargeable zinc ion battery (ZIB) has a huge potential, owing to its large overpotential for hydrogen evolution reaction (HER) (Fang, et al., 2018, Xu, et al., 2012, Glatz, et al., 2020, Zeng, et al., 2019). Apart from that, Zn holds a number of advantages over others, namely: high Earth abundance (low cost), high theoretical capacity (820 mAh g-1), low redox potential (-0.762 V vs SHE) and nontoxicity (Blanc, et al., 2020). Clearly, the electrochemical stability of Zn in aqueous solutions enlightens an opportunity to develop a “green” rechargeable battery.The aqueous ZIB consists of three main components, the Zn anode, electrolyte (e.g. Zn salts, such as ZnSO4, ZnNO3 or Zn(CF3SO3) in water) (Zhang, et al., 2016) and the cathode material (layered transition metal oxides, metal sulphides, polyaniline compounds, Prussian blue analogues etc.) (Fang, et al., 2018). Most scientific contributions on ZIB are devoted to the development of high-capacity and stable cathode materials. Owing to the cost effectiveness, environmental friendliness, and high theoretical capacity, Mn and V-based layered oxides are popular as cathode materials (Xu, et al., 2012, Alfaruqi, et al., 2015, Zhang, et al., 2019, Wei, et al., 2019). However, due to the +2 charge of Zn, it can suffer s
可充电电池是太阳能、风能和潮汐能等可再生能源的主要储能选择(Park等人，2019,Tarascon, 2010)。此外，每个人都拥有一个由可充电电池供电的设备。这些设备中的大多数都是由锂离子电池(lib)供电，因为它们具有可充电性和高能量密度(Shin等人，2019)。然而，随着时间的推移，可充电电池将失去保持电量的能力，迫使消费者丢弃电池或产品，最终进入垃圾填埋场。由于锂的高化学活性以及有机溶剂基电解质的毒性和可燃性，锂离子电池引起了惊人的安全和环境问题(Yang, et al.， 2018)。虽然Na+/K+电池是可能的替代品，但这些技术也使用有机电解质。因此，有一个巨大的动力去探索一种持久、环保、经济的电池化学。基于水基电解质的可充电电池是一种革命性的替代品，在能源存储研究界占有重要地位。除了其他优点外，水还具有比有机电解质(~10-2 - 10-3 S cm-1)更高的离子电导率(1 S cm-1)，这是电池高倍率循环的理想选择(Fang等人，2018,Winter等人，2004)。可充电水性电池的开发正在进行中，目前存在基于单价离子(如K+)和多价离子(如Al3+， Zn2+和Mg2+)的系统(Liu等，2014,Zhang等，2017)。多价体系是更可取的，因为它们的多种氧化还原状态保证了高比容量和能量密度。在多价体系中，可充电锌离子电池(ZIB)由于其大的析氢反应(HER)过电位而具有巨大的潜力(Fang等，2018;Xu等，2012;Glatz等，2020;Zeng等，2019)。除此之外，锌比其他材料具有许多优势，即:高地球丰度(低成本)，高理论容量(820 mAh g-1)，低氧化还原电位(-0.762 V vs SHE)和无毒(Blanc等，2020)。显然，锌在水溶液中的电化学稳定性为开发“绿色”可充电电池提供了机会。含水ZIB由三个主要组成部分组成:锌阳极、电解质(例如锌盐，如ZnSO4、ZnNO3或水中的Zn(CF3SO3)) (Zhang等，2016)和阴极材料(层状过渡金属氧化物、金属硫化物、聚苯胺化合物、普鲁士蓝类似物等)(Fang等，2018)。ZIB的大多数科学贡献都致力于开发高容量和稳定的阴极材料。由于成本效益、环境友好性和高理论容量，Mn和v基层状氧化物作为正极材料很受欢迎(Xu等，2012;Alfaruqi等，2015;Zhang等，2019;Wei等，2019)。然而，由于Zn的+2电荷，它可能与层状宿主材料发生严重的静电相互作用，导致电荷转移动力学缓慢(Yang, et al.， 2018)。金属离子(Zn2+， Mg2+， Ca2+， Li+， Na+)或结构水分子在层间的掺入可以减轻这些相互作用并提高结构稳定性(Zeng等，2019,Lewis等，2022)。阴极材料在水溶液电解中的溶解是另一个问题，通常通过电解质优化来解决(Zhao等，2019)。当考虑阳极时，阳极表面Zn枝晶的生长是ZIB扩展的主要瓶颈(Zhao, et al.， 2019)，即Zn的局域成核，而在预形成的晶体中沉积新的Zn进一步加剧了这一瓶颈。这些锌枝晶导致电池内部短路。此外，由于沉积的高活性锌表面可能发生副反应(腐蚀，HER)，导致副产物和低库仑效率(Zhao等，2018)。解决这些问题的主要策略有四种:(i)电解质优化，(ii) Zn阳极表面修饰，(iii) 3D Zn主机设计，以及(iv)电化学协议开发(Blanc等，2020)。其中，无机(ZnO, TiO2, CaCO3) (Kang,et al.， 2018, Kim, et al.， 2020, Zhao, et al.， 2020, Xie, et al.， 2020)和有机(聚酰胺，聚乙烯丁基)(Zhao, et al.， 2019, Hao, et al.， 2020)涂层对Zn阳极进行表面钝化是一种很有前途的新方法。虽然取得了一些进展，但有效和实际可行的延缓锌枝晶生长的方法还不够。电沉积Zn的最终命运严重依赖于初始成核模式和纳米级表面动力学(Zhao, et al.， 2019; White, et al.， 2012)。 研究人员已经认识到这一点的重要性，并通过非原位原子力显微镜(AFM)、扫描电子显微镜(SEM)和透射电子显微镜(TEM)等技术分析了枝晶的形成(Song等人，2016)，但这些“走走停停”的方法限制了对动态过程的实时研究。操作技术是观察锌沉积过程中微纳结构演变的必要手段，这将有助于建立锌阳极沉积动力学和转移动力学。因此，先进的操作表征工具有望指导安全、经济、环保的水性电池和超级电容器的发展，用于未来的电网规模储能。
{"title":"Aqueous Rechargeable Batteries for Green Energy Storage: The Zinc Ion Chemistry","authors":"Joseph F. S. Fernando","doi":"10.31357/vjs.v25i01.5919","DOIUrl":"https://doi.org/10.31357/vjs.v25i01.5919","url":null,"abstract":"Rechargeable battery is the leading energy storage option for renewable power sources such as solar, wind and tidal (Park, et al., 2019, Tarascon, 2010). Furthermore, everyone owns a device powered by a rechargeable battery. Most of these devices are powered by lithium ion batteries (LIBs) owing to their rechargeability and high-energy density (Shin, et al., 2019). However, the rechargeable battery will lose its ability to retain a charge over time, forcing the consumer to discard the battery or product, which ends up in landfills. Owing to the high chemical activity of Li and the toxicity and flammability of organic solvent-based electrolytes, LIBs cause alarming safety and environmental issues (Yang, et al., 2018). Although Na+/K+ batteries are possible alternatives, these technologies also utilize organic electrolytes. Hence, there is a huge motivation to explore a battery chemistry that is long lasting, environmentally friendly, and cost-efficient. Rechargeable batteries based on water-based electrolytes are a revolutionary alternative and hold a prominent place in the energy storage research community. Along with other advantages, water also has a higher ionic conductivity (1 S cm-1) than organic electrolytes (~10-2 – 10-3 S cm-1) which is ideal for high rate cycling of batteries (Fang, et al., 2018, Winter, et al., 2004).The development of rechargeable aqueous batteries is ongoing, and there are systems based on monovalent ions (e.g. K+) and multivalent ions (e.g. Al3+, Zn2+ and Mg2+) (Liu, et al., 2014, Zhang, et al., 2017). Multivalent systems are more desirable given that their multiple redox states promise high specific capacity and energy density. Among multivalent systems, the rechargeable zinc ion battery (ZIB) has a huge potential, owing to its large overpotential for hydrogen evolution reaction (HER) (Fang, et al., 2018, Xu, et al., 2012, Glatz, et al., 2020, Zeng, et al., 2019). Apart from that, Zn holds a number of advantages over others, namely: high Earth abundance (low cost), high theoretical capacity (820 mAh g-1), low redox potential (-0.762 V vs SHE) and nontoxicity (Blanc, et al., 2020). Clearly, the electrochemical stability of Zn in aqueous solutions enlightens an opportunity to develop a “green” rechargeable battery.The aqueous ZIB consists of three main components, the Zn anode, electrolyte (e.g. Zn salts, such as ZnSO4, ZnNO3 or Zn(CF3SO3) in water) (Zhang, et al., 2016) and the cathode material (layered transition metal oxides, metal sulphides, polyaniline compounds, Prussian blue analogues etc.) (Fang, et al., 2018). Most scientific contributions on ZIB are devoted to the development of high-capacity and stable cathode materials. Owing to the cost effectiveness, environmental friendliness, and high theoretical capacity, Mn and V-based layered oxides are popular as cathode materials (Xu, et al., 2012, Alfaruqi, et al., 2015, Zhang, et al., 2019, Wei, et al., 2019). However, due to the +2 charge of Zn, it can suffer s","PeriodicalId":214405,"journal":{"name":"Vidyodaya Journal of Science","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125746752","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 : 2021-12-30DOI: 10.31357/vjs.v24i02.5413
Rizana Azees, Asitha T. Cooray, K.G.U.R. Kumarasinghe
Cobalt (Co2+) is an essential constituent in the human body while excessive exposure leads to severe systemic toxic reactions which highlight the importance of developing effective methods to detect Co2+ ions. A simple and highly efficient fluorescence enhanced turn OFF-ON chemosensor was synthesized to detect the paramagnetic Co2+. The ligand, N-((1H-indol-3-yl)(phenyl)methyl)aniline (L), was synthesized in 92% yield by means of hydrated ferric chloride catalyzed one -pot multicomponent microwave irradiation in the presence of Indole, benzaldehyde, and aniline as reactants. The major green principles of waste prevention, high atom economy (94.3%), green solvent, higher energy efficiency, and catalysis were the highlights of the ligand synthesis. The ligand exhibited remarkable fluorescence enhancement with Co2+ and a turn ON ratio of over 160-fold in MeOH/H2O (at pH 3.5) solution at an excitation wavelength of 369 nm in the Ultra-Violet range. The detection limit of L- Co2+ was 2.2 μM. The excitation and the emission spectra indicated stoke’s shift of 93 nm which supports the fluorescence enhancement observed in L- Co2+ with respect to the free ligand. The Job’s plot indicated fluorometric sensing of Co2+ ascribed to the complex formation with a stoichiometric ratio of 2:1 (L- Co2+). Furthermore, the high linearity (r2 =0.992) observed in the Benesi Hildebrand plot in a wide concentration range of 0.5−80 μM confirmed the above stoichiometric ratio. The association constant (Ka) for the L-Co2+ was determined to be 8.382 ×1 04 M−1 ± 5.8 ×103M−1.The prepared Co2+ fluorometric probe indicated long-term stability in −18 ℃ up to 45 days. Furthermore, the presence of Fe2+ and Fe3+ in the medium with Co2+ exhibited an interference effect in the fluorescence intensities. Upon further concentration studies, it was evident that the interference of Fe2+ and Fe3+ starts around 10.00 μM and rises exponentially. Keywords: MCR, Green synthesis, Fluorescent Chemo-sensor, Turn OFF-ON, Cobalt (II), indole derivatives
{"title":"Microwave-assisted one-pot multicomponent synthesis of indole derived fluorometric probe for detection of Co2+ ions","authors":"Rizana Azees, Asitha T. Cooray, K.G.U.R. Kumarasinghe","doi":"10.31357/vjs.v24i02.5413","DOIUrl":"https://doi.org/10.31357/vjs.v24i02.5413","url":null,"abstract":"Cobalt (Co2+) is an essential constituent in the human body while excessive exposure leads to severe systemic toxic reactions which highlight the importance of developing effective methods to detect Co2+ ions. A simple and highly efficient fluorescence enhanced turn OFF-ON chemosensor was synthesized to detect the paramagnetic Co2+. The ligand, N-((1H-indol-3-yl)(phenyl)methyl)aniline (L), was synthesized in 92% yield by means of hydrated ferric chloride catalyzed one -pot multicomponent microwave irradiation in the presence of Indole, benzaldehyde, and aniline as reactants. The major green principles of waste prevention, high atom economy (94.3%), green solvent, higher energy efficiency, and catalysis were the highlights of the ligand synthesis. The ligand exhibited remarkable fluorescence enhancement with Co2+ and a turn ON ratio of over 160-fold in MeOH/H2O (at pH 3.5) solution at an excitation wavelength of 369 nm in the Ultra-Violet range. The detection limit of L- Co2+ was 2.2 μM. The excitation and the emission spectra indicated stoke’s shift of 93 nm which supports the fluorescence enhancement observed in L- Co2+ with respect to the free ligand. The Job’s plot indicated fluorometric sensing of Co2+ ascribed to the complex formation with a stoichiometric ratio of 2:1 (L- Co2+). Furthermore, the high linearity (r2 =0.992) observed in the Benesi Hildebrand plot in a wide concentration range of 0.5−80 μM confirmed the above stoichiometric ratio. The association constant (Ka) for the L-Co2+ was determined to be 8.382 ×1 04 M−1 ± 5.8 ×103M−1.The prepared Co2+ fluorometric probe indicated long-term stability in −18 ℃ up to 45 days. Furthermore, the presence of Fe2+ and Fe3+ in the medium with Co2+ exhibited an interference effect in the fluorescence intensities. Upon further concentration studies, it was evident that the interference of Fe2+ and Fe3+ starts around 10.00 μM and rises exponentially. \u0000Keywords: MCR, Green synthesis, Fluorescent Chemo-sensor, Turn OFF-ON, Cobalt (II), indole derivatives","PeriodicalId":214405,"journal":{"name":"Vidyodaya Journal of Science","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125448185","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 : 2021-12-30DOI: 10.31357/vjs.v24i02.5416
S.V. Narasimhan, W.G.S.S. Karunarathne
Objective: To documenting the voice onset time in voiced and unvoiced stop consonants in Sinhala and to investigating the effects of age and gender on voice onset time values in Sinhalese speakers. Methods: Three groups of participants were employed. Group 1 included 20 children, Group 2 included 20 adults and Group 3 consisted of 20 elderly subjects. All the subjects spoke the dialect of central province of Sri Lanka. Words consisting of three Sinhala short vowels /a/, /i/ and /u/ in were recorded. Voice onset time values from two voiced and voiceless stop consonants were extracted. Results: Voiced stop consonants had significantly longer voice onset time values compared to voiceless stop consonants. Significant effect of age as well as gender on voice onset time values were also observed. Conclusion: Supplementary investigations on the normative aspects of voice onset time among the Sinhala population would provide additional insights and validated tools for indexing the articulatory and acoustic characteristics of stop consonants in Sinhalese. Keywords: Voice Onset Time, Sinhalese, Elderly, Sinhala, Acoustic analysis
{"title":"Effect of Age and Gender on Voice Onset Time: Data from Sinhalese","authors":"S.V. Narasimhan, W.G.S.S. Karunarathne","doi":"10.31357/vjs.v24i02.5416","DOIUrl":"https://doi.org/10.31357/vjs.v24i02.5416","url":null,"abstract":"Objective: To documenting the voice onset time in voiced and unvoiced stop consonants in Sinhala and to investigating the effects of age and gender on voice onset time values in Sinhalese speakers.\u0000Methods: Three groups of participants were employed. Group 1 included 20 children, Group 2 included 20 adults and Group 3 consisted of 20 elderly subjects. All the subjects spoke the dialect of central province of Sri Lanka. Words consisting of three Sinhala short vowels /a/, /i/ and /u/ in were recorded. Voice onset time values from two voiced and voiceless stop consonants were extracted.\u0000Results: Voiced stop consonants had significantly longer voice onset time values compared to voiceless stop consonants. Significant effect of age as well as gender on voice onset time values were also observed.\u0000Conclusion: Supplementary investigations on the normative aspects of voice onset time among the Sinhala population would provide additional insights and validated tools for indexing the articulatory and acoustic characteristics of stop consonants in Sinhalese.\u0000Keywords: Voice Onset Time, Sinhalese, Elderly, Sinhala, Acoustic analysis","PeriodicalId":214405,"journal":{"name":"Vidyodaya Journal of Science","volume":"73 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126987743","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 : 2021-12-30DOI: 10.31357/vjs.v24i02.5414
S.N. Wijesooriya, N. Adassooriya
In this research, novel carboxymethyl cellulose (CMC) based nanocomposite film containing 5%wt of halloysite nanotubes (HNT) was fabricated via solvent casting method as a potential biodegradable packaging material. The performances of the nanocomposite packaging material was investigated by assessing the moisture content, moisture uptake, water solubility, water vapor barrier properties and opacity. The incorporation of 5%wt HNT into the film remarkably reduced the moisture uptake by ∼ 28.01% at 97% RH and 31.08% at 40% RH. Water permeability value of CMC/HNT film showed as 7.08 ± 0.26 × 10−11 gm/m2Pas at freezing, 3.37 ± 0.33 × 10−11 gm/m2Pas at refrigeration and 1.14 ± 0.00 × 10−11 gm/m2Pas at ambient environmental conditions respectively. Subsequent to the thermal annealing process, the water vapor permeation ability was drastically declined in the HNT added nanocomposite films at all three different conditions (freezing, refrigeration and ambient) due to enhancing the crystalline structure. Furthermore, the addition of nanofillers into the polymer matrix significantly induced the UV blocking property of the film. These findings disclosed that prepared CMC/5%HNT nanocomposite films can be a potential food packaging material.Keywords: barrier properties, carboxy methyl cellulose, halloysite nanotubes
{"title":"Water barrier properties of carboxymethyl cellulose/halloysite nanotubes nanocomposite to be used in food packaging applications","authors":"S.N. Wijesooriya, N. Adassooriya","doi":"10.31357/vjs.v24i02.5414","DOIUrl":"https://doi.org/10.31357/vjs.v24i02.5414","url":null,"abstract":"In this research, novel carboxymethyl cellulose (CMC) based nanocomposite film containing 5%wt of halloysite nanotubes (HNT) was fabricated via solvent casting method as a potential biodegradable packaging material. The performances of the nanocomposite packaging material was investigated by assessing the moisture content, moisture uptake, water solubility, water vapor barrier properties and opacity. The incorporation of 5%wt HNT into the film remarkably reduced the moisture uptake by ∼ 28.01% at 97% RH and 31.08% at 40% RH. Water permeability value of CMC/HNT film showed as 7.08 ± 0.26 × 10−11 gm/m2Pas at freezing, 3.37 ± 0.33 × 10−11 gm/m2Pas at refrigeration and 1.14 ± 0.00 × 10−11 gm/m2Pas at ambient environmental conditions respectively. Subsequent to the thermal annealing process, the water vapor permeation ability was drastically declined in the HNT added nanocomposite films at all three different conditions (freezing, refrigeration and ambient) due to enhancing the crystalline structure. Furthermore, the addition of nanofillers into the polymer matrix significantly induced the UV blocking property of the film. These findings disclosed that prepared CMC/5%HNT nanocomposite films can be a potential food packaging material.Keywords: barrier properties, carboxy methyl cellulose, halloysite nanotubes","PeriodicalId":214405,"journal":{"name":"Vidyodaya Journal of Science","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131978579","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 : 2021-12-30DOI: 10.31357/vjs.v24i02.5405
P.A.L. Jayathilake, M. A. Jayasinghe, J. Walpita, K.P.R.I. Dilani
Most of the medicinal plants utilized in traditional medicine are spices. Majority of those spices are widely used for aroma, flavour and colour in cuisine though they behave as appetizers, digestives, preventives and aphrodisiacs. Their antimicrobial properties are in a broad spectrum that provides a considerable immunity development within the human body. This review summarizes the beneficial characteristics of major active constituents in turmeric and ginger and their presumed pharmacological potential to safeguard human health.Keywords: Turmeric, Ginger, Curcumin, Human health, Active Ingredients, Nanotechnology
{"title":"Turmeric and Ginger as Health Protective Food Sources - An Integrative Review","authors":"P.A.L. Jayathilake, M. A. Jayasinghe, J. Walpita, K.P.R.I. Dilani","doi":"10.31357/vjs.v24i02.5405","DOIUrl":"https://doi.org/10.31357/vjs.v24i02.5405","url":null,"abstract":"Most of the medicinal plants utilized in traditional medicine are spices. Majority of those spices are widely used for aroma, flavour and colour in cuisine though they behave as appetizers, digestives, preventives and aphrodisiacs. Their antimicrobial properties are in a broad spectrum that provides a considerable immunity development within the human body. This review summarizes the beneficial characteristics of major active constituents in turmeric and ginger and their presumed pharmacological potential to safeguard human health.Keywords: Turmeric, Ginger, Curcumin, Human health, Active Ingredients, Nanotechnology","PeriodicalId":214405,"journal":{"name":"Vidyodaya Journal of Science","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115468570","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 : 2021-12-30DOI: 10.31357/vjs.v24i02.5403
Gathsaurie Neelika Malavige
Although the scientific community had been predicting and preparing for a pandemic for the last 10 years, many policy makers did not envision that a virus could cause such devastation to human life, economies and to the social structure. COVID-19 has taught us many bitter lessons and while moving forward it is important to understand that this current pandemic is yet to end. However, COVID-19 is unlikely to be the last pandemic that we face, Due to certain human activities such as urbanization, deforestation, increased human and animal interactions and climate change, we will see more pandemics emerging in the coming years. Preparedness and anticipation of such an event is the only way forward.
{"title":"COVID-19 Pandemic: lessons learnt and the way forward","authors":"Gathsaurie Neelika Malavige","doi":"10.31357/vjs.v24i02.5403","DOIUrl":"https://doi.org/10.31357/vjs.v24i02.5403","url":null,"abstract":"Although the scientific community had been predicting and preparing for a pandemic for the last 10 years, many policy makers did not envision that a virus could cause such devastation to human life, economies and to the social structure. COVID-19 has taught us many bitter lessons and while moving forward it is important to understand that this current pandemic is yet to end. However, COVID-19 is unlikely to be the last pandemic that we face, Due to certain human activities such as urbanization, deforestation, increased human and animal interactions and climate change, we will see more pandemics emerging in the coming years. Preparedness and anticipation of such an event is the only way forward.","PeriodicalId":214405,"journal":{"name":"Vidyodaya Journal of Science","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124043848","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 : 2021-12-30DOI: 10.31357/vjs.v24i02.5402
Veranja Karunaratne
Small molecules has been a main concern in the pharmaceutical industry for as long as they have existed. Enormous libraries of compounds have been collected and they in turn nurture drug discovery research. For example, big pharma, has in their compound libraries ranging from 500,000 to several million. Examining the drugs in the market, it is clear from where most are arriving: natural origin; out of the 1,328 new chemical entities approved as drugs between 1981 and 2016, only 359 were purely of synthetic origin. In the list of remaining ones, 326 were “biologics”, and 94 were vaccines. Importantly, 549 were from natural origin or arose motivated from natural compounds. Furthermore, anticancer compounds arising during the same period (1981–2014), only 23 were purely synthetic (Newman and Cragg, 2016). Natural origin can count for three categories: unaltered natural products; distinct mixture of natural products and natural product derivatives isolated from plants or other living organisms such as fungi, sponges, lichens, or microorganisms; and products modified through application of medicinal chemistry. There are many examples covering a wide spectrum of diseases: anticancer drugs such as docetaxel (Taxotere™), paclitaxel (Taxol™), vinblastine, podophyllotoxin (Condylin™), or etoposide; steroidal hormones such as progesterone, norgestrel, or cortisone; cardiac glycosides such as digitoxigenin; antibiotics like penicillin, streptomycin, and cephalosporins.
{"title":"Potential Pharmaceutical Application of Endemic Plants: When will Sri Lanka Understand the Economic Value Chain?","authors":"Veranja Karunaratne","doi":"10.31357/vjs.v24i02.5402","DOIUrl":"https://doi.org/10.31357/vjs.v24i02.5402","url":null,"abstract":"Small molecules has been a main concern in the pharmaceutical industry for as long as they have existed. Enormous libraries of compounds have been collected and they in turn nurture drug discovery research. For example, big pharma, has in their compound libraries ranging from 500,000 to several million. Examining the drugs in the market, it is clear from where most are arriving: natural origin; out of the 1,328 new chemical entities approved as drugs between 1981 and 2016, only 359 were purely of synthetic origin. In the list of remaining ones, 326 were “biologics”, and 94 were vaccines. Importantly, 549 were from natural origin or arose motivated from natural compounds. Furthermore, anticancer compounds arising during the same period (1981–2014), only 23 were purely synthetic (Newman and Cragg, 2016). Natural origin can count for three categories: unaltered natural products; distinct mixture of natural products and natural product derivatives isolated from plants or other living organisms such as fungi, sponges, lichens, or microorganisms; and products modified through application of medicinal chemistry. There are many examples covering a wide spectrum of diseases: anticancer drugs such as docetaxel (Taxotere™), paclitaxel (Taxol™), vinblastine, podophyllotoxin (Condylin™), or etoposide; steroidal hormones such as progesterone, norgestrel, or cortisone; cardiac glycosides such as digitoxigenin; antibiotics like penicillin, streptomycin, and cephalosporins.","PeriodicalId":214405,"journal":{"name":"Vidyodaya Journal of Science","volume":"202 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116174700","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 : 2021-12-30DOI: 10.31357/vjs.v24i02.5415
D. P. Lakmini, Helani Munasinghe, A. Buddhika G. Silva, P.G.S.M. De Silva, Renuka Jayatissa
High salt intake elevates the risk of non-communicable diseases such as high blood pressure, cardiovascular diseases and stroke worldwide. Sri Lanka has recorded in 2010 as the country with highest average fish & fish products consumption in South Asia. In the current study, salt in ten types of commonly available dried fish namely; sprats, prawns, smoothbelly sardinella, queen fish, cat fish, sail fish, shark, skipjack tuna, Bombay duck and trenched sardinella was analyzed and determined salt reduction methods with minimal protein loss. Four salt reduction methods were tested; Method 1: washed with water at Room Temperature (RT) for five times; Method 2: washed with water for five times at RT and kept in hot water for 5min; Method 3: washed with water for five times at RT and boiled for 5min; Method 4: washed with water for five times at RT and kept in coconut water for 5min. Using Volhard method, sodium chloride was analyzed while protein was determined using Kjeldahl method. All four methods showed significant reduction of salt level in tested dried fish (p < 0.05). Among the tested salt reduction methods, Method 3 showed the highest salt reduction for all types of dried fish except smoothbelly sardinella and cat fish.The highest salt mean value of 28.8% was recorded in queen fish and the lowest mean value of 12.8% was recorded in smoothbelly sardinella. The highest protein loss was recorded in Method 3. To reduce considerable amount of salt, the easiest and fairly effective method is method 1 except for prawns and Shark. Although higher salt reduction showed in method 2 and 3, they are not recommended due to high protein loss, high energy expenditure and reduction of freshness of dried fish. Method 4 can be applied for all dried fish types because it is economical and reduces considerable amount of salt, removes less amount of protein comparatively. The results revealed that all tested dried fish except smoothbelly sardinella contain significantly high amount of salt (p < 0.05) than the standard value specified (12%) by the Sri Lanka Standards Institution (SLSI).Keywords: Dried fish, protein loss, salt-intake, salt reduction, non-communicable diseases
{"title":"Evaluation of salt content and effectiveness of excessive salt reduction methods in selected commercially available dried fish types in Sri Lanka","authors":"D. P. Lakmini, Helani Munasinghe, A. Buddhika G. Silva, P.G.S.M. De Silva, Renuka Jayatissa","doi":"10.31357/vjs.v24i02.5415","DOIUrl":"https://doi.org/10.31357/vjs.v24i02.5415","url":null,"abstract":"High salt intake elevates the risk of non-communicable diseases such as high blood pressure, cardiovascular diseases and stroke worldwide. Sri Lanka has recorded in 2010 as the country with highest average fish & fish products consumption in South Asia. In the current study, salt in ten types of commonly available dried fish namely; sprats, prawns, smoothbelly sardinella, queen fish, cat fish, sail fish, shark, skipjack tuna, Bombay duck and trenched sardinella was analyzed and determined salt reduction methods with minimal protein loss. Four salt reduction methods were tested; Method 1: washed with water at Room Temperature (RT) for five times; Method 2: washed with water for five times at RT and kept in hot water for 5min; Method 3: washed with water for five times at RT and boiled for 5min; Method 4: washed with water for five times at RT and kept in coconut water for 5min. Using Volhard method, sodium chloride was analyzed while protein was determined using Kjeldahl method. All four methods showed significant reduction of salt level in tested dried fish (p < 0.05). Among the tested salt reduction methods, Method 3 showed the highest salt reduction for all types of dried fish except smoothbelly sardinella and cat fish.The highest salt mean value of 28.8% was recorded in queen fish and the lowest mean value of 12.8% was recorded in smoothbelly sardinella. The highest protein loss was recorded in Method 3. To reduce considerable amount of salt, the easiest and fairly effective method is method 1 except for prawns and Shark. Although higher salt reduction showed in method 2 and 3, they are not recommended due to high protein loss, high energy expenditure and reduction of freshness of dried fish. Method 4 can be applied for all dried fish types because it is economical and reduces considerable amount of salt, removes less amount of protein comparatively. The results revealed that all tested dried fish except smoothbelly sardinella contain significantly high amount of salt (p < 0.05) than the standard value specified (12%) by the Sri Lanka Standards Institution (SLSI).Keywords: Dried fish, protein loss, salt-intake, salt reduction, non-communicable diseases","PeriodicalId":214405,"journal":{"name":"Vidyodaya Journal of Science","volume":"22 4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123246051","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 : 2021-06-04DOI: 10.31357/VJS.V24I01.4961
S. Narasimhan, W. Karunarathne
This study was conducted to document the effect of age, gender and vowel type on vowel space area in Sinhala language. Three groups of participants were employed. Group 1 included 20 children, Group 2 included 20 adults and Group 3 consisted of 20 elderly subjects. All the subjects spoke the dialect of central province of Sri Lanka. Words consisting of three Sinhala short vowels /a/, /i/ and /u/ in were recorded. Formant frequencies of vowels were extracted and vowel space area was constructed. The results showed that the formant frequencies were significantly higher for children compared with those of adults.Female subjects had significantly higher formant frequency values than male subjects. Effect of vowel types were also significant on the formant frequencies and vowel space area. Sinhala also follows universal criteria of resonance characteristics and vocal tract constriction.Keywords: vowel space area, formant frequencies, Sinhala, vowel articulation
{"title":"Effect of Age, Gender and Vowel Type on Vowel Space Area in Sinhala Speakers","authors":"S. Narasimhan, W. Karunarathne","doi":"10.31357/VJS.V24I01.4961","DOIUrl":"https://doi.org/10.31357/VJS.V24I01.4961","url":null,"abstract":"This study was conducted to document the effect of age, gender and vowel type on vowel space area in Sinhala language. Three groups of participants were employed. Group 1 included 20 children, Group 2 included 20 adults and Group 3 consisted of 20 elderly subjects. All the subjects spoke the dialect of central province of Sri Lanka. Words consisting of three Sinhala short vowels /a/, /i/ and /u/ in were recorded. Formant frequencies of vowels were extracted and vowel space area was constructed. The results showed that the formant frequencies were significantly higher for children compared with those of adults.Female subjects had significantly higher formant frequency values than male subjects. Effect of vowel types were also significant on the formant frequencies and vowel space area. Sinhala also follows universal criteria of resonance characteristics and vocal tract constriction.Keywords: vowel space area, formant frequencies, Sinhala, vowel articulation","PeriodicalId":214405,"journal":{"name":"Vidyodaya Journal of Science","volume":"82 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126271257","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 : 2021-06-04DOI: 10.31357/VJS.V24I01.4964
S. Shayanthavi, R. Kapilan
This study was aimed to produce Single Cell Protein (SCP) from underutilied, abundantly found marine seaweed Turbinaria sp. using natural yeast from palmyrah (Borassus flabellifer) toddy. Turbinaria sp. were collected, sun-dried, ground to powder form and Turbinaria solution was made by mixing distilled water and this was used as a growth medium throughout the experiment without adding any supplements. The experiments were performed in a shaking incubator with the fermentation medium of Turbinaria sp. 100 g/L (10%) inoculated with 10 mL natural palmyrah toddy. Fermentation was carried out at 29 C for 72 h and the crude protein content was determined using Kjeldahl apparatus (38.46%). When the growth temperature was optimised at 35 C, crude protein yield obtained was significantly increased by 1.36 times than the initial non-optimised condition with temperature 27 C. When fermentation time was optimised as 48 h (44.33%), crude protein yield was significantly increased by 1.14 times than the initial fermentation time (24 h-38.55%). When different combinations of Turbinaria sp. media and inoculum ratio (55:05, 50:10, 40:20, 30:30 and 20:40) were used as medium, crude protein yield was significantly increased by 1.44 times (50:10-43.72%) than the initial media inoculum ratio (55:05-30.21%). When initial pH of the media was changed (5.0, 6.0, 7.0, 8.0 and 9.0), significantly higher relative crude protein yield was obtained with the initial pH value 6.0 (Turbinaria medium-90.97%). Amino acid analysis revealed that the SCP produced from the Turbinaria medium had all the essential amino acids with comparatively higher amount of methionine (3.9%) and lower amount of threonine (0.2%). Vitamin B analysis revealed that SCP yield from Turbinaria medium contained thiamin (0.85 mg/100 g) and riboflavin (3.2 mg/100 g). After the optimisation of culture growing conditions and media composition, SCP production from the excessively grown, underutilised seaweed Turbinaria, was significantly increased by 1.13 times (from 38.46 to 43.72%) with palmyrah toddy mix.
{"title":"Bioconversion of Single Cell Protein from Underutilised Seaweed Turbinaria sp. using Natural Palmyrah Toddy Yeast","authors":"S. Shayanthavi, R. Kapilan","doi":"10.31357/VJS.V24I01.4964","DOIUrl":"https://doi.org/10.31357/VJS.V24I01.4964","url":null,"abstract":"This study was aimed to produce Single Cell Protein (SCP) from underutilied, abundantly found marine seaweed Turbinaria sp. using natural yeast from palmyrah (Borassus flabellifer) toddy. Turbinaria sp. were collected, sun-dried, ground to powder form and Turbinaria solution was made by mixing distilled water and this was used as a growth medium throughout the experiment without adding any supplements. The experiments were performed in a shaking incubator with the fermentation medium of Turbinaria sp. 100 g/L (10%) inoculated with 10 mL natural palmyrah toddy. Fermentation was carried out at 29 C for 72 h and the crude protein content was determined using Kjeldahl apparatus (38.46%). When the growth temperature was optimised at 35 C, crude protein yield obtained was significantly increased by 1.36 times than the initial non-optimised condition with temperature 27 C. When fermentation time was optimised as 48 h (44.33%), crude protein yield was significantly increased by 1.14 times than the initial fermentation time (24 h-38.55%). When different combinations of Turbinaria sp. media and inoculum ratio (55:05, 50:10, 40:20, 30:30 and 20:40) were used as medium, crude protein yield was significantly increased by 1.44 times (50:10-43.72%) than the initial media inoculum ratio (55:05-30.21%). When initial pH of the media was changed (5.0, 6.0, 7.0, 8.0 and 9.0), significantly higher relative crude protein yield was obtained with the initial pH value 6.0 (Turbinaria medium-90.97%). Amino acid analysis revealed that the SCP produced from the Turbinaria medium had all the essential amino acids with comparatively higher amount of methionine (3.9%) and lower amount of threonine (0.2%). Vitamin B analysis revealed that SCP yield from Turbinaria medium contained thiamin (0.85 mg/100 g) and riboflavin (3.2 mg/100 g). After the optimisation of culture growing conditions and media composition, SCP production from the excessively grown, underutilised seaweed Turbinaria, was significantly increased by 1.13 times (from 38.46 to 43.72%) with palmyrah toddy mix.","PeriodicalId":214405,"journal":{"name":"Vidyodaya Journal of Science","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132299082","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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