Pub Date : 2024-03-08DOI: 10.3126/bibechana.v21i1.58815
M. S. Paudel, H.K. Kushuwala, S. Bhattarai
This work presents the comparative study of the properties of dust within the W51 Giant Molecular Cloud (GMC) located at (RA, DEC) (J2000): 290.91°, +14.51°. In the infrared data of Improved Reprocessing of the IRAS (IRIS) the dust structure seems single and isolated having size 0.45°×0.45° but in AKARI infrared survey it breaks into two isolated regions having size 0.15°×0.15° and 0.10°×0.10°, represented by AKARI-I and AKARI-II respectively. In IRIS map, 60 and 100 mm and in AKARI map, 90 and 140 mm image are used for extraction of the infrared flux. The dust color temperature (Td) and dust mass (Md) are calculated from the infrared flux and found to 30.34 K in IRIS and 27.40 K and 23.55 K in AKARI-I and AKARI-II. A linear relationship between the infrared flux at two wavelength is found except AKADI-I. The dust mass per pixels in the isolated (core) region is found to be increase compare to total study region. To quantify the relation between flux, dust color temperature and dust mass the regression analysis is used and observed spectrum of relation. A huge SIMBAD background objected is found embedded in the dust cloud which might have been shaping the spatial variation of temperature and mass within dust cloud.
{"title":"Comparative study of the dust color temperature and dust mass within the isolated dust in W51 giant molecular cloud in IRIS and AKARI data","authors":"M. S. Paudel, H.K. Kushuwala, S. Bhattarai","doi":"10.3126/bibechana.v21i1.58815","DOIUrl":"https://doi.org/10.3126/bibechana.v21i1.58815","url":null,"abstract":"This work presents the comparative study of the properties of dust within the W51 Giant Molecular Cloud (GMC) located at (RA, DEC) (J2000): 290.91°, +14.51°. In the infrared data of Improved Reprocessing of the IRAS (IRIS) the dust structure seems single and isolated having size 0.45°×0.45° but in AKARI infrared survey it breaks into two isolated regions having size 0.15°×0.15° and 0.10°×0.10°, represented by AKARI-I and AKARI-II respectively. In IRIS map, 60 and 100 mm and in AKARI map, 90 and 140 mm image are used for extraction of the infrared flux. The dust color temperature (Td) and dust mass (Md) are calculated from the infrared flux and found to 30.34 K in IRIS and 27.40 K and 23.55 K in AKARI-I and AKARI-II. A linear relationship between the infrared flux at two wavelength is found except AKADI-I. The dust mass per pixels in the isolated (core) region is found to be increase compare to total study region. To quantify the relation between flux, dust color temperature and dust mass the regression analysis is used and observed spectrum of relation. A huge SIMBAD background objected is found embedded in the dust cloud which might have been shaping the spatial variation of temperature and mass within dust cloud.","PeriodicalId":8759,"journal":{"name":"Bibechana","volume":"17 29","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140257953","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 : 2024-03-08DOI: 10.3126/bibechana.v21i1.58405
Prakash Khatri, N. Adhikari
Reducing lattice thermal conductivity (κl) that reflects the material’s heat-carrying capacity through lattice phonon vibrations is crucial for optimizing the figure of merit (zT). Using density functional theory (DFT) and density functional perturbation theory (DFPT), present work considers the structural, electronic, magnetic, and phonon properties of the XNiSn (X=Ti, Zr, Hf ) half Heusler (hH) compounds. TiNiSn, ZrNiSn, and HfNiSn are identified as semiconductors with indirect band gaps of 0.43 eV, 0.47 eV and 0.39 eV, respectively, exhibiting dynamical stability. The temperature- dependent κl of hH XNiSn are compared using Slack’s model with two approaches for analyzing phonon velocity: elastic constants from quasi- harmonic approximation (QHA) as implemented in the Thermo_pw code and slope of phonon bands based on DFPT. At room temperature, TiNiSn, ZrNiSn and HfNiSn have κl values of 28.61 Wm−1K−1, 34.61 Wm−1K−1 and 29.85 Wm−1K−1 respectively using phonon velocity from slopes of phonon bands based on DFPT. These values show deviation of 1.48%, 6.29%, and 5.82% to those κl values 29.01 Wm−1K−1’, 36.79 Wm−1K−1 and 31.59 Wm−1K−1 for TiNiSn, ZrNiSn and HfNiSn respectively using QHA.
{"title":"Lattice thermal conductivity in half-Heusler compounds XNiSn (X=Ti, Zr, Hf) using Slack's model","authors":"Prakash Khatri, N. Adhikari","doi":"10.3126/bibechana.v21i1.58405","DOIUrl":"https://doi.org/10.3126/bibechana.v21i1.58405","url":null,"abstract":"Reducing lattice thermal conductivity (κl) that reflects the material’s heat-carrying capacity through lattice phonon vibrations is crucial for optimizing the figure of merit (zT). Using density functional theory (DFT) and density functional perturbation theory (DFPT), present work considers the structural, electronic, magnetic, and phonon properties of the XNiSn (X=Ti, Zr, Hf ) half Heusler (hH) compounds. TiNiSn, ZrNiSn, and HfNiSn are identified as semiconductors with indirect band gaps of 0.43 eV, 0.47 eV and 0.39 eV, respectively, exhibiting dynamical stability. The temperature- dependent κl of hH XNiSn are compared using Slack’s model with two approaches for analyzing phonon velocity: elastic constants from quasi- harmonic approximation (QHA) as implemented in the Thermo_pw code and slope of phonon bands based on DFPT. At room temperature, TiNiSn, ZrNiSn and HfNiSn have κl values of 28.61 Wm−1K−1, 34.61 Wm−1K−1 and 29.85 Wm−1K−1 respectively using phonon velocity from slopes of phonon bands based on DFPT. These values show deviation of 1.48%, 6.29%, and 5.82% to those κl values 29.01 Wm−1K−1’, 36.79 Wm−1K−1 and 31.59 Wm−1K−1 for TiNiSn, ZrNiSn and HfNiSn respectively using QHA.","PeriodicalId":8759,"journal":{"name":"Bibechana","volume":"14 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140258080","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 : 2024-03-08DOI: 10.3126/bibechana.v21i1.54503
P. B. Adhikari, Nabraj Khanal
Among the natural disasters, landslides, flood, thunderstorm, fire, are major destructive disaster. In every season, fire is the main cause of the death of the people which frequently occurred in spring and winter seasons. The landslide seems to be very destructive in the summer season, flood is also in the summer season, and thunderbolt occurs frequently in spring and summer seasons (pre-monsoon period). The different disaster occurred in different season frequently and have more effect on human, animals, and huge loss of property due to it. Due to the geographical structure of our scenario, the destruction seems to be high in Nepal. Hence, the disasters can’t be stopped, but can be reduced and awareness program should be conducted to mitigate its effects.
{"title":"Seasonal variations of disasters in Nepal","authors":"P. B. Adhikari, Nabraj Khanal","doi":"10.3126/bibechana.v21i1.54503","DOIUrl":"https://doi.org/10.3126/bibechana.v21i1.54503","url":null,"abstract":"Among the natural disasters, landslides, flood, thunderstorm, fire, are major destructive disaster. In every season, fire is the main cause of the death of the people which frequently occurred in spring and winter seasons. The landslide seems to be very destructive in the summer season, flood is also in the summer season, and thunderbolt occurs frequently in spring and summer seasons (pre-monsoon period). The different disaster occurred in different season frequently and have more effect on human, animals, and huge loss of property due to it. Due to the geographical structure of our scenario, the destruction seems to be high in Nepal. Hence, the disasters can’t be stopped, but can be reduced and awareness program should be conducted to mitigate its effects.","PeriodicalId":8759,"journal":{"name":"Bibechana","volume":"122 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140257206","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 : 2024-03-08DOI: 10.3126/bibechana.v21i1.60048
B. R. Poudel, R. Aryal, K. N. Ghimire, H. Paudyal, M. R. Pokhrel
A dynamic biosorption of arsenite in a fixed bed column packed with TiO2 impregnated pomegranate peel (PP@TiO2) has been investigated in this work, which is important to identify the effectiveness and affordability of an adsorbent in actual practice. To create an active adsorption site for As (III) ions, pomegranate peel powder (PP) was impregnated with TiO2. Under various operating parameters, the performance of a column packed with PP@TiO2 for adsorbing As (III) ions was evaluated. Breakthrough curve modelling showed that the bed depth service time (BDST) and Thomas models agreed well with the experimental data. The maximum column capacity of PP@TiO2 using the Thomas model was found to have resembled experimental value with high values of coefficient of determination. Therefore from these results, we may anticipate that PP@TiO2 can be a strong contender for the treatment of wastewater that has traces amount of the As (III) ion in a fixed bed system.
这项工作研究了用浸渍石榴皮的二氧化钛（PP@TiO2）填充的固定床柱对亚砷酸盐的动态生物吸附，这对于确定吸附剂在实际应用中的有效性和经济性非常重要。为了给 As (III) 离子创造一个活性吸附位点，石榴皮粉末（PP）被浸渍在 TiO2 中。在不同的操作参数下，对使用 PP@TiO2 填料的色谱柱吸附 As (III) 离子的性能进行了评估。突破曲线模型显示，床层深度服务时间（BDST）和托马斯模型与实验数据吻合良好。使用托马斯模型得出的 PP@TiO2 的最大柱容量与实验值相似，且确定系数较高。因此，从这些结果中，我们可以预见 PP@TiO2 在固定床系统中处理含有微量 As (III) 离子的废水时，将是一个强有力的竞争者。
{"title":"Potential removal of arsenite from contaminated water using a fixed bed column packed with TiO2-impregnated pomegranate peel powder","authors":"B. R. Poudel, R. Aryal, K. N. Ghimire, H. Paudyal, M. R. Pokhrel","doi":"10.3126/bibechana.v21i1.60048","DOIUrl":"https://doi.org/10.3126/bibechana.v21i1.60048","url":null,"abstract":"A dynamic biosorption of arsenite in a fixed bed column packed with TiO2 impregnated pomegranate peel (PP@TiO2) has been investigated in this work, which is important to identify the effectiveness and affordability of an adsorbent in actual practice. To create an active adsorption site for As (III) ions, pomegranate peel powder (PP) was impregnated with TiO2. Under various operating parameters, the performance of a column packed with PP@TiO2 for adsorbing As (III) ions was evaluated. Breakthrough curve modelling showed that the bed depth service time (BDST) and Thomas models agreed well with the experimental data. The maximum column capacity of PP@TiO2 using the Thomas model was found to have resembled experimental value with high values of coefficient of determination. Therefore from these results, we may anticipate that PP@TiO2 can be a strong contender for the treatment of wastewater that has traces amount of the As (III) ion in a fixed bed system.","PeriodicalId":8759,"journal":{"name":"Bibechana","volume":"34 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140257703","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 : 2023-11-30DOI: 10.3126/bibechana.v20i3.58041
Prakash Joshi, Umesh Lawaju, Anupama K.C., Min Nakarmi, Ramani Pradhan
Candle soot, carbon samples prepared by flame-soot method, was characterized and investigated for its catalytic ability for the reduction of tri-iodide ions aiming to substitute expensive platinum based electrode used in dye-sensitized solar cells (DSCs). The Energy Dispersive X-ray Spectroscopy of the candle soot samples revealed that the soot contains 96% carbon. Similarly, Scanning Electron Microscopy images show that the candle soot consists of interconnected carbon nanoparticles of size ∼50 nm. Furthermore, X-ray Diffraction and Raman spectroscopy showed that the candle soot consists of disordered and ordered graphitic carbons in a comparable proportion. The catalytic ability of the candle soot was compared with that of platinum by Electrochemical Impedance Spectroscopy of the symmetrical electrochemical cells. The charge transfer resistance (Rct) at the candle soot-electrolyte interface was observed to be ∼4.42 Ω cm2 compared to ∼ 5.04 Ω cm2 that of the platinum-electrolyte interface. The candle soot was prepared by a simple method using low-cost material; hence, it can be a low-cost and efficient counter electrode material alternate to the platinum used in counter electrodes of DSCs.
{"title":"Characterization of carbon derived from candle by flame-soot method for counter electrodes of dye-sensitized solar cells","authors":"Prakash Joshi, Umesh Lawaju, Anupama K.C., Min Nakarmi, Ramani Pradhan","doi":"10.3126/bibechana.v20i3.58041","DOIUrl":"https://doi.org/10.3126/bibechana.v20i3.58041","url":null,"abstract":"Candle soot, carbon samples prepared by flame-soot method, was characterized and investigated for its catalytic ability for the reduction of tri-iodide ions aiming to substitute expensive platinum based electrode used in dye-sensitized solar cells (DSCs). The Energy Dispersive X-ray Spectroscopy of the candle soot samples revealed that the soot contains 96% carbon. Similarly, Scanning Electron Microscopy images show that the candle soot consists of interconnected carbon nanoparticles of size ∼50 nm. Furthermore, X-ray Diffraction and Raman spectroscopy showed that the candle soot consists of disordered and ordered graphitic carbons in a comparable proportion. The catalytic ability of the candle soot was compared with that of platinum by Electrochemical Impedance Spectroscopy of the symmetrical electrochemical cells. The charge transfer resistance (Rct) at the candle soot-electrolyte interface was observed to be ∼4.42 Ω cm2 compared to ∼ 5.04 Ω cm2 that of the platinum-electrolyte interface. The candle soot was prepared by a simple method using low-cost material; hence, it can be a low-cost and efficient counter electrode material alternate to the platinum used in counter electrodes of DSCs.","PeriodicalId":8759,"journal":{"name":"Bibechana","volume":"57 12 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139198634","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 : 2023-11-30DOI: 10.3126/bibechana.v20i3.55476
C. B. Khadka
The paper demonstrates that the existing mathematical formulas of linear momentum, force and kinetic energy in physics are incomplete, since such formulas have been formulated without incorporation of mass-energy equivalence relation E = mc2. Therefore, new reformulations of the main equations of linear momentum, force and kinetic energy in the realm of special relativity are proposed. The proposed formulas provide same mathematical outcomes as the old formulas, displaying same behavior of the system when velocity approaches to speed of light, but, most importantly, comprise only velocity of the light and mass of object to provide well-defined expressions. [Formulae available with the full text]. These formulas vividly reveal that every physical variable depends solely on relativistic mass. Therefore, it modifies Newton’s second law of motion and states that the force depends on rate of change of relativistic mass of object rather than its velocity. In this highly interesting topic, primary purpose here has been to present a succinct and the carefully reasoned account of a new aspect of the Newton’s second law of motion which properly allows to derive the new mathematical formulas of linear momentum, force and kinetic energy.
本文论证了物理学中现有的线性动量、力和动能的数学公式是不完整的，因为这些公式是在没有纳入质能等价关系 E = mc2 的情况下制定的。因此，我们提出了狭义相对论中线性动量、力和动能主要方程的新重述。所提出的公式提供了与旧公式相同的数学结果，在速度接近光速时显示了系统的相同行为，但最重要的是，只包括光速和物体质量，从而提供了定义明确的表达式。[公式见全文]。这些公式生动地揭示了每个物理变量都只取决于相对论质量。因此，它修改了牛顿第二运动定律，指出力取决于物体相对论质量的变化率，而不是其速度。在这个非常有趣的话题中，本文的主要目的是对牛顿第二运动定律的一个新方面进行简明扼要和仔细推理的阐述，从而正确推导出线性动量、力和动能的新数学公式。
{"title":"An accurate theoretical formula for linear momentum, force and kinetic energy","authors":"C. B. Khadka","doi":"10.3126/bibechana.v20i3.55476","DOIUrl":"https://doi.org/10.3126/bibechana.v20i3.55476","url":null,"abstract":"The paper demonstrates that the existing mathematical formulas of linear momentum, force and kinetic energy in physics are incomplete, since such formulas have been formulated without incorporation of mass-energy equivalence relation E = mc2. Therefore, new reformulations of the main equations of linear momentum, force and kinetic energy in the realm of special relativity are proposed. The proposed formulas provide same mathematical outcomes as the old formulas, displaying same behavior of the system when velocity approaches to speed of light, but, most importantly, comprise only velocity of the light and mass of object to provide well-defined expressions. [Formulae available with the full text]. These formulas vividly reveal that every physical variable depends solely on relativistic mass. Therefore, it modifies Newton’s second law of motion and states that the force depends on rate of change of relativistic mass of object rather than its velocity. In this highly interesting topic, primary purpose here has been to present a succinct and the carefully reasoned account of a new aspect of the Newton’s second law of motion which properly allows to derive the new mathematical formulas of linear momentum, force and kinetic energy.","PeriodicalId":8759,"journal":{"name":"Bibechana","volume":"108 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139200433","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This review paper explores the application of Life Cycle Assessment (LCA) within the domain of civil engineering, aiming to provide a comprehensive overview of current research, methodologies, challenges, and future trends. LCA serves as a pivotal tool for assessing the environmental impact of infrastructure projects, yet gaps persist in its integration with socioeconomic dimensions, regional considerations, and dynamic modeling. By analyzing existing literature and scholarly discussions, this review identifies research gaps and proposes directions for enhancing the applicability and effectiveness of LCA in civil engineering. Moreover, it examines future trends such as the integration of advanced technologies, stakeholder engagement, and policy implementation, poised to shape the landscape of LCA practices in the civil engineering sector. Ultimately, this review paper contributes to the understanding of LCA's potential to drive sustainable decision-making in infrastructure development, paving the way for more informed and environmentally conscious practices.
{"title":"Comprehensive review of LCA studies in Civil Engineering","authors":"Ishwor Thapa, Nirmal Prasad Baral, Krishna Raj Adhikari","doi":"10.3126/bibechana.v20i3.58552","DOIUrl":"https://doi.org/10.3126/bibechana.v20i3.58552","url":null,"abstract":"This review paper explores the application of Life Cycle Assessment (LCA) within the domain of civil engineering, aiming to provide a comprehensive overview of current research, methodologies, challenges, and future trends. LCA serves as a pivotal tool for assessing the environmental impact of infrastructure projects, yet gaps persist in its integration with socioeconomic dimensions, regional considerations, and dynamic modeling. By analyzing existing literature and scholarly discussions, this review identifies research gaps and proposes directions for enhancing the applicability and effectiveness of LCA in civil engineering. Moreover, it examines future trends such as the integration of advanced technologies, stakeholder engagement, and policy implementation, poised to shape the landscape of LCA practices in the civil engineering sector. Ultimately, this review paper contributes to the understanding of LCA's potential to drive sustainable decision-making in infrastructure development, paving the way for more informed and environmentally conscious practices.","PeriodicalId":8759,"journal":{"name":"Bibechana","volume":"93 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139205253","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 : 2023-11-30DOI: 10.3126/bibechana.v20i3.57711
Keshab Bhattarai, Devendra Dhakal, Indira Pandey, Bimala Subba, K. Sharma
This study focused on chemical profiling and assessed the total phenolic and flavonoid content as well as the antioxidant and antibacterial effect of the medicinal plant Berberis asiatica. The results revealed that this plant has high concentrations of TPC (Total phenol content) and TFC (Total flavonoid content) of 37.686 ± 2.728 mg GAE/g and 115.568 ± 8.012 mg QE/g, respectively. The DPPH free radical scavenging assay demonstrated strong inhibition, with an IC50 of 205.7 ± 5.353 μg/mL, and also showed robust antibacterial properties against Staphylococcus aureus and Klebsiella pneumoniae with a zone of inhibition (ZOI) of 14 mm and 19 mm, respectively. The extract exhibited an excellent inhibitory potential against S. aureus, and K. pneumoniae with an MIC (Minimum inhibitory concentration) of 0.39 mg/mL, and 3.125 mg/mL respectively, indicating significant inhibitory action. Furthermore, the MBC (Minimum bactericidal concentration) for both S. aureus and K. pneumoniae was found to be 6.25 mg/mL, emphasizing the extract's consistent bactericidal effectiveness against these bacteria. These findings underscore the potential utility of the methanolic extract of Berberis asiatica as a natural antibacterial agent. GC-MS analysis of hexane fraction indicates the plant is rich in secondary metabolites, specifically 2,2-dimethyl-3-pentanol, 2-methyl-2-pentanol, 2,5-dimethyl-4-hydroxy-3-hexanone, 3-hexanol, 4-methyl-2-pentanol are identified. Overall, this study highlights the importance of plant-based natural products as potential sources of antioxidants and antibacterial agents that contributes to the future drug development process.
{"title":"Phytochemistry, Biological Activities, and Chemical Profiling of Berberis asiatica","authors":"Keshab Bhattarai, Devendra Dhakal, Indira Pandey, Bimala Subba, K. Sharma","doi":"10.3126/bibechana.v20i3.57711","DOIUrl":"https://doi.org/10.3126/bibechana.v20i3.57711","url":null,"abstract":"This study focused on chemical profiling and assessed the total phenolic and flavonoid content as well as the antioxidant and antibacterial effect of the medicinal plant Berberis asiatica. The results revealed that this plant has high concentrations of TPC (Total phenol content) and TFC (Total flavonoid content) of 37.686 ± 2.728 mg GAE/g and 115.568 ± 8.012 mg QE/g, respectively. The DPPH free radical scavenging assay demonstrated strong inhibition, with an IC50 of 205.7 ± 5.353 μg/mL, and also showed robust antibacterial properties against Staphylococcus aureus and Klebsiella pneumoniae with a zone of inhibition (ZOI) of 14 mm and 19 mm, respectively. The extract exhibited an excellent inhibitory potential against S. aureus, and K. pneumoniae with an MIC (Minimum inhibitory concentration) of 0.39 mg/mL, and 3.125 mg/mL respectively, indicating significant inhibitory action. Furthermore, the MBC (Minimum bactericidal concentration) for both S. aureus and K. pneumoniae was found to be 6.25 mg/mL, emphasizing the extract's consistent bactericidal effectiveness against these bacteria. These findings underscore the potential utility of the methanolic extract of Berberis asiatica as a natural antibacterial agent. GC-MS analysis of hexane fraction indicates the plant is rich in secondary metabolites, specifically 2,2-dimethyl-3-pentanol, 2-methyl-2-pentanol, 2,5-dimethyl-4-hydroxy-3-hexanone, 3-hexanol, 4-methyl-2-pentanol are identified. Overall, this study highlights the importance of plant-based natural products as potential sources of antioxidants and antibacterial agents that contributes to the future drug development process.","PeriodicalId":8759,"journal":{"name":"Bibechana","volume":"22 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139196881","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}
Machine learning represents an emerging branch of artificial intelligence, centering on the enhancement of algorithms in computer programs through the utilization of data and the accumulation of research-driven knowledge. The requirement for artificial intelligence in materials science is essential due to the significant need for innovative high-performance materials on a large scale. In this report, the gradient boosting regression tree model of machine learning was applied to predict the lattice constants of cubic and trigonal MX2 systems (M=transition metal and X=chalcogen atoms). The theoretical/experimental values of the materials were compared to the predicted values to calculate the standard errors such as RMSE (root mean square error) and MAE (mean absolute error). The features used to predict lattice constants were ionic radius, lattice angles, bandgap, formation energy, total magnetic moment, density and oxidation states. The features versus contribution barplot has been drawn to reveal the contribution level of each parameter in the degree of [0,1] to obtain the predictions. This report provides a precise account of the prediction methodology for lattice parameters of the transition metal dichalcogenides family, a process that was previously not reported.
{"title":"Machine learning driven prediction of lattice constants in transition metal dichalcogenides","authors":"Bhupendra Sharma, Laxman Chaudhary, Rajendra Adhikari, Madhav Prasad Ghimire","doi":"10.3126/bibechana.v20i3.57732","DOIUrl":"https://doi.org/10.3126/bibechana.v20i3.57732","url":null,"abstract":"Machine learning represents an emerging branch of artificial intelligence, centering on the enhancement of algorithms in computer programs through the utilization of data and the accumulation of research-driven knowledge. The requirement for artificial intelligence in materials science is essential due to the significant need for innovative high-performance materials on a large scale. In this report, the gradient boosting regression tree model of machine learning was applied to predict the lattice constants of cubic and trigonal MX2 systems (M=transition metal and X=chalcogen atoms). The theoretical/experimental values of the materials were compared to the predicted values to calculate the standard errors such as RMSE (root mean square error) and MAE (mean absolute error). The features used to predict lattice constants were ionic radius, lattice angles, bandgap, formation energy, total magnetic moment, density and oxidation states. The features versus contribution barplot has been drawn to reveal the contribution level of each parameter in the degree of [0,1] to obtain the predictions. This report provides a precise account of the prediction methodology for lattice parameters of the transition metal dichalcogenides family, a process that was previously not reported.","PeriodicalId":8759,"journal":{"name":"Bibechana","volume":"55 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139201644","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 : 2023-11-30DOI: 10.3126/bibechana.v20i3.57470
H. Neupane, Prakash Khatri, Arun Devkota, N. Adhikari
This study examined the effect of Tc & Nb impurity atoms on MoS2 (Tc-MoS2 & Nb-MoS2 ), and adsorption of water molecule on impurities defected MoS2 (Tc-W-MoS2 & Nb-W-MoS2) material from first-principles calculations. By the estimation of their ground state energy and binding energy, they are stable 2D materials. From band structure and density of states (DoS) calculations, Tc & Nbimpurities affect the nature of pristine MoS2. It is found that Tc-MoS2 has n-type & Nb-MoS2 has p-type semiconducting nature. Water interaction on Tc-MoS2 & Nb-MoS2 slightly changes the electronic properties and impacts the bandgap, which enhanced the electronic performance of material than that of pristine MoS2. The magnetic properties of Tc-MoS2, Nb-MoS2, Tc-W-MoS2, and Nb-W-MoS2 are analyzed and found to exhibit an uneven distribution of up-spin and down-spin states of electrons in the orbital of atoms near the Fermi level. It reflects that they have magnetic properties. The non-magnetic MoS2 material changes in to weak magnetic defected-MoS2 materials due to the presence of Tc, Nb and adsorbed water molecule. It means, impurity defects add to magnetic properties of pristine MoS2. Magnetic properties on defected MoS2 occurred due to the dominant contributions of spin states of 4d-orbital of Mo, Tc, Nb atoms, and 3p-orbital of S atoms in the structures. This study highlights the impact of Tc & Nb impurity atoms and adsorbed water molecule on impurities defected MoS2. The studied materials have potential applications in the fields of catalysis, nanoelectronics, biomedicine, and magnetic sensors on the basis of their electronic and magnetic properties.
本研究通过第一性原理计算，研究了 Tc 和 Nb 杂质原子对 MoS2（Tc-MoS2 和 Nb-MoS2）的影响，以及杂质缺陷 MoS2（Tc-W-MoS2 和 Nb-W-MoS2）材料对水分子的吸附。根据基态能和结合能的估算，它们都是稳定的二维材料。通过能带结构和态密度（DoS）计算，Tc 和 Nb 杂质会影响原始 MoS2 的性质。研究发现，锝-MoS2 具有 n 型半导体性质，而铌-MoS2 具有 p 型半导体性质。水对 Tc-MoS2 和 Nb-MoS2 的相互作用会轻微改变其电子特性并影响其带隙，从而使材料的电子性能优于原始 MoS2。对 Tc-MoS2、Nb-MoS2、Tc-W-MoS2 和 Nb-W-MoS2 的磁性能进行分析后发现，它们在费米级附近的原子轨道上呈现出电子的上旋和下旋态的不均匀分布。这反映出它们具有磁性。由于 Tc、Nb 和吸附水分子的存在，非磁性 MoS2 材料变成了弱磁性缺陷 MoS2 材料。这意味着杂质缺陷增加了原始 MoS2 的磁性。缺陷 MoS2 的磁性是由于结构中 Mo、Tc、Nb 原子的 4d-orbital 自旋态和 S 原子的 3p-orbital 自旋态的主要贡献。这项研究强调了 Tc 和 Nb 杂质原子以及吸附水分子对杂质缺陷 MoS2 的影响。基于其电子和磁性能，所研究的材料在催化、纳米电子学、生物医学和磁性传感器领域具有潜在的应用前景。
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