Bibechana Pub Date : 2024-03-08 DOI: 10.3126/bibechana.v21i1.58815

M. S. Paudel, H.K. Kushuwala, S. Bhattarai

{"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}

引用次数: 0

Lattice thermal conductivity in half-Heusler compounds XNiSn (X=Ti, Zr, Hf) using Slack's model 使用斯拉克模型计算半休斯勒化合物 XNiSn（X=钛、锆、铪）的晶格热导率

Bibechana Pub Date : 2024-03-08 DOI: 10.3126/bibechana.v21i1.58405

Prakash Khatri, N. Adhikari

{"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}

引用次数: 0

Seasonal variations of disasters in Nepal 尼泊尔灾害的季节性变化

Bibechana Pub Date : 2024-03-08 DOI: 10.3126/bibechana.v21i1.54503

P. B. Adhikari, Nabraj Khanal

引用次数: 0

Potential removal of arsenite from contaminated water using a fixed bed column packed with TiO2-impregnated pomegranate peel powder 使用浸渍石榴皮粉末的二氧化钛填料固定床柱去除受污染水体中亚砷酸盐的潜力

Bibechana Pub Date : 2024-03-08 DOI: 10.3126/bibechana.v21i1.60048

B. R. Poudel, R. Aryal, K. N. Ghimire, H. Paudyal, M. R. Pokhrel

引用次数: 0

Characterization of carbon derived from candle by flame-soot method for counter electrodes of dye-sensitized solar cells 染料敏化太阳能电池对电极用火焰烟尘法分析蜡烛碳的特性

Bibechana Pub Date : 2023-11-30 DOI: 10.3126/bibechana.v20i3.58041

Prakash Joshi, Umesh Lawaju, Anupama K.C., Min Nakarmi, Ramani Pradhan

{"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}

引用次数: 0

An accurate theoretical formula for linear momentum, force and kinetic energy 线性动量、力和动能的精确理论公式

Bibechana Pub Date : 2023-11-30 DOI: 10.3126/bibechana.v20i3.55476

C. B. Khadka

{"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}

引用次数: 0

Comprehensive review of LCA studies in Civil Engineering 土木工程中的生命周期评估研究综述

Bibechana Pub Date : 2023-11-30 DOI: 10.3126/bibechana.v20i3.58552

Ishwor Thapa, Nirmal Prasad Baral, Krishna Raj Adhikari

引用次数: 0

Phytochemistry, Biological Activities, and Chemical Profiling of Berberis asiatica 小檗的植物化学、生物活性和化学成分分析

Bibechana Pub Date : 2023-11-30 DOI: 10.3126/bibechana.v20i3.57711

Keshab Bhattarai, Devendra Dhakal, Indira Pandey, Bimala Subba, K. Sharma

{"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}

引用次数: 0

Machine learning driven prediction of lattice constants in transition metal dichalcogenides 机器学习驱动的过渡金属二钴化物晶格常数预测

Bibechana Pub Date : 2023-11-30 DOI: 10.3126/bibechana.v20i3.57732

Bhupendra Sharma, Laxman Chaudhary, Rajendra Adhikari, Madhav Prasad Ghimire

{"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}

引用次数: 0

Electronic and magnetic performance of MoS2 monolayer via Tc & Nb impurities defect and water adsorption 通过 Tc 和 Nb 杂质缺陷及水吸附实现 MoS2 单层的电子和磁性能

Bibechana Pub Date : 2023-11-30 DOI: 10.3126/bibechana.v20i3.57470

H. Neupane, Prakash Khatri, Arun Devkota, N. Adhikari

{"title":"Electronic and magnetic performance of MoS2 monolayer via Tc & Nb impurities defect and water adsorption","authors":"H. Neupane, Prakash Khatri, Arun Devkota, N. Adhikari","doi":"10.3126/bibechana.v20i3.57470","DOIUrl":"https://doi.org/10.3126/bibechana.v20i3.57470","url":null,"abstract":"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.","PeriodicalId":8759,"journal":{"name":"Bibechana","volume":"59 3 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139198256","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}

引用次数: 0

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