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Assessment of the antibacterial activity of lemongrass-extracted essential oil 柠檬草提取精油的抗菌活性评估
Pub Date : 2023-11-30 DOI: 10.3126/bibechana.v20i3.58311
Prem Raj Joshi, Prakash Raj Pant, A. Bist, Gunananda Pant, Bishweshwar Pant, P. Saud
Lemongrass is one of the medicinal plants having significant applications to cure various diseases. This study aims at extracting essential oils from lemongrass plants and examining their antibacterial activity. The sample of lemongrass for this study was collected from Kailali District, Nepal. The leaves of lemongrass were collected, washed, cut into small pieces, and dried in the sun. Then pieces of lemongrass were steam distilled for about 4 hours using the Clevenger apparatus, and oil was extracted. The extracted essential oil was further utilized to study its antibacterial activity in human pathogens, namely Staphylococcus aureus (S. aureus: gram-positive bacteria), by Agar diffusion and broth dilution methods. It was found that the zone of inhibition for S. aureus in concentrations of 100%, 75%, 50%, and 25% was about 25 mm, 11 mm, 9 mm, and 0 mm, respectively. In addition, it is clear from this study that the gram-positive bacteria were sensitive to essential oils. The lowest and highest zones of inhibition were shown against S. aureus at 25% and 100% concentrations, respectively. The zone of inhibition at 100% concentration is 25 mm and at 25% concentration is 0 mm, so lemongrass oil is effective against drug-resistant organisms only at high concentrations.
香茅是一种药用植物,在治疗各种疾病方面具有重要用途。本研究旨在从柠檬草植物中提取精油,并检测其抗菌活性。本研究的香茅样本采集自尼泊尔凯拉利县。采集柠檬草的叶子,洗净,切成小块,在阳光下晒干。然后用 Clevenger 仪器对柠檬草进行约 4 小时的蒸汽蒸馏,提取精油。萃取出的精油被进一步用于研究其对人类病原体,即金黄色葡萄球菌(S. aureus:革兰氏阳性菌)的抗菌活性,采用的方法是琼脂扩散法和肉汤稀释法。结果发现,浓度为 100%、75%、50% 和 25%时,金黄色葡萄球菌的抑菌区分别约为 25 毫米、11 毫米、9 毫米和 0 毫米。此外,这项研究还表明,革兰氏阳性菌对精油很敏感。金黄色葡萄球菌在 25% 和 100% 浓度下的抑菌区分别最小和最大。100%浓度下的抑菌区为 25 毫米,25%浓度下的抑菌区为 0 毫米,因此柠檬草精油只有在高浓度下才对耐药菌有效。
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引用次数: 0
Measurement of background radiation in Jhapa, Ilam, Panchthar, and Taplejung districts of Nepal 尼泊尔贾帕、伊拉姆、潘奇塔尔和塔布勒琼县的本底辐射测量结果
Pub Date : 2023-11-30 DOI: 10.3126/bibechana.v20i3.57882
Arun Kumar Shrestha, Roshan Nepal, Kamala Shrestha, Dijan Regmi, Ganesh Kumar Shrestha, Buddha Ram Shah, Ram Prasad Koirala
In this study, we investigated the levels of background radiation in different locations across the Eastern part of Koshi province, specifically in Taplejung, Panchthar, Ilam, and Jhapa. We used a portable Geiger Muller counter to collect data from twenty different locations, with five sites taken from each district. The average absorbed dose rate was found to be 0.243±0.035 mSv/y. The highest measured value of absorbed dose was 0.335±0.041 mSv/y at Pathivara temple in Taplejung, and the lowest was found to be 0.197±0.039 mSv/y at Kakarvita, Jhapa. The results suggest that these four districts do not pose any radiation risk because it was below the threshold of risk (1mSv/y). We also measured the variation of absorption dose with altitude which is positively correlated with altitude with a correlation coefficient of +0.57. This might be because of the surge in cosmic radiation with an increase in altitude.
在这项研究中,我们调查了甲西省东部不同地点的本底辐射水平,特别是塔布勒琼、潘奇塔尔、伊拉姆和贾帕。我们使用便携式盖革-穆勒计数器从 20 个不同地点收集数据,每个地区选取 5 个地点。平均吸收剂量率为 0.243±0.035 mSv/y。吸收剂量的最高测量值为 0.335±0.041 mSv/y,位于塔普勒琼的 Pathivara 寺,最低值为 0.197±0.039 mSv/y,位于贾帕的 Kakarvita。结果表明,这四个地区不存在任何辐射风险,因为其辐射剂量低于风险阈值(1mSv/y)。我们还测量了吸收剂量随海拔高度的变化,吸收剂量与海拔高度呈正相关,相关系数为 +0.57。这可能是由于随着海拔高度的增加,宇宙辐射量也随之增加。
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引用次数: 0
Time and Space Domain Prediction of Water Quality Parameters of Bagmati River Using Deep Learning Methods 利用深度学习方法对巴格马蒂河水质参数进行时域和空域预测
Pub Date : 2023-11-30 DOI: 10.3126/bibechana.v20i3.57736
Pujan Bashyal, Mandira Adhikari, Nanda Bikram Adhikari
Bagmati river is biologically, geologically, religiously and historically significant among the river systems of the Kathmandu Valley. The river is affected by five major tributaries, including Manohara, Dhobi Khola, Tukucha, Bishnumati, and Balkhu Khola, which significantly impact the water chemistry inside the Kathmandu Valley. The data of water quality parameters pH, dissolved oxygen, turbidity, temperature, oxygen reduction potential, conductivity, total dissolved solids, salinity among others was collected using fixed sensors (in period of 5 seconds) and mobile sensors (with latitude and longitude) along the river. The observation is important for two reasons, one because it was collected in real-time and fine scale, which is not normally possible with traditional ways, and next such observation was done for the first time in Bagmati River. The aim of this study was to predict water quality parameters of the Bagmati River using machine learning time series models, specifically ARIMA and LSTM. The LSTM model was designed with one input layer, one encoder layer, one repeat layer, one decoder layer, and one output dense layer to separate the output into temporal slices. Additionally, a DNN model was employed for location-based prediction, utilizing two input layers for latitude and longitude and seven output layers for the seven water quality parameters considered for study. The models demonstrated promising performance, but further data collection and parameter variation are recommended for continued optimization.
在加德满都谷地的河流系统中,巴格马蒂河具有重要的生物、地质、宗教和历史意义。巴格马蒂河受到五条主要支流的影响,包括马诺哈拉河(Manohara)、多比库拉河(Dhobi Khola)、图库查河(Tukucha)、比什努马蒂河(Bishnumati)和巴尔库库拉河(Balkhu Khola),这五条支流对加德满都谷地内的水化学产生了重大影响。利用沿河的固定传感器(以 5 秒为周期)和移动传感器(带经纬度)收集了水质参数 pH 值、溶解氧、浊度、温度、氧还原电位、电导率、溶解固体总量、盐度等数据。这次观测非常重要,原因有二:其一,观测数据是实时和精细采集的,传统方法通常无法实现;其二,这是首次在巴格马蒂河进行此类观测。本研究的目的是利用机器学习时间序列模型(特别是 ARIMA 和 LSTM)预测巴格马蒂河的水质参数。LSTM 模型设计有一个输入层、一个编码器层、一个重复层、一个解码器层和一个输出密集层,以便将输出分成时间片。此外,还采用了 DNN 模型进行基于位置的预测,利用两个输入层表示经纬度,七个输出层表示研究中考虑的七个水质参数。这些模型表现出良好的性能,但建议进一步收集数据并改变参数,以便继续优化。
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引用次数: 0
Cr3+ substitution effect on Co-Cu and Cu-Co nano ferrites on structural and morphological properties Cr3+ 取代对 Co-Cu 和 Cu-Co 纳米铁氧体结构和形态特性的影响
Pub Date : 2023-11-30 DOI: 10.3126/bibechana.v20i3.58411
D. Parajuli, N. Murali, K. Samatha
The Cr3+ substituted Co-Cu (Co0.7Cu0.3Fe2-xCrxO4) and Cu-Co (Cu0.7Co0.3Fe2-xCrxO4) where x = 0.0, 0.05, 0.1, 0.15, 0.2 and 0.25 nano ferrite composite were prepared with the sol-gel approach. Their structural, dc electrical resistivity, and magnetic properties were analyzed. XRD shows the single-phase spinel ferrite. Adding Cr3+ ions decreases the lattice volume and the size of the crystallite respectively. FESEM images show non-spherical particles on a largely uniform surface shape with decreasing grain size on doping Cr3+. The FTIR pattern supports the XRD patterns for spinel ferrite.
采用溶胶-凝胶法制备了 Cr3+ 取代的 Co-Cu(Co0.7Cu0.3Fe2-xCrxO4)和 Cu-Co(Cu0.7Co0.3Fe2-xCrxO4)纳米铁氧体复合材料,其中 x = 0.0、0.05、0.1、0.15、0.2 和 0.25。分析了它们的结构、直流电阻率和磁性能。XRD 显示了单相尖晶石铁氧体。加入 Cr3+ 离子后,晶格体积和晶粒大小分别减小。FESEM 图像显示,非球形颗粒表面形状基本均匀,掺入 Cr3+ 后晶粒尺寸减小。傅立叶变换红外光谱图支持尖晶石铁氧体的 XRD 图。
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引用次数: 0
Correlative study of Aerosol Optical Depth with Precipitable water over five AERONET station across the world 全球五个 AERONET 站的气溶胶光学深度与可降水量的相关研究
Pub Date : 2023-11-30 DOI: 10.3126/bibechana.v20i3.57153
Santosh Sapkota, Sabina Gautam, Aayush Gautam, Bhairab Ale
Ground-based measurements were taken at various locations, including Kathmandu Bode, Beijing, Gandhi College (located in South Asian zone, highly polluted area), Canberra, and UNC Gaitan (located in South Eastern zone, low polluted area), from January to December 2016. The study investigated the seasonal and inter-annual AOD that were obtained using CIMEL Sunphotometer, as a part of the Aerosol Robotic Network (AERONET). The data showed that Kathmandu (0.45±0.01), Gandhi College (0.45±0.02 and Beijing (0.85±0.03) had higher AOD values compared to other stations, with Kathmandu being a high-altitude site. The analysis found that pre-monsoon AOD were higher over Kathmandu (0.45±0.01), Gandhi College (0.45±0.02), UNC Gaitan (0.28±0.001), and Canberra (0.06±0.002). On the other hand, the monsoon AOD was higher over Beijing (0.85±0.03). The study identified various factors contributing to the higher AOD values in specific regions. Beijing, Gandhi College, and Kathmandu, located in Asian monsoon regions, experienced high aerosol loading due to economic activities, vehicles, urbanization, vegetation fire, land clearing for crop cultivation, as well as winter biomass burning, heating needs, and pollution from bricks kilns, factories, and vehicles. Canberra and UNC Gaitan had higher AOD values primarily due to biomass burning and dust. AOD values are higher for shorter wavelength and vice-versa. We conducted a correlation analysis between AOD and perceptible water at different wavelengths and observed one to one correspondence. The columnar water vapor (CWV) exhibited a high correlation with AOD in Canberra (Coefficient of determination, R2 = 0.61) at 1640 nm but had no relationship with AOD in Gandhi College (Coefficient of determination, R2 = 0) at 1640nm. There is weak negative correlation between AOD and preceptable water over Kathmandu and UNC Gaitan, but have positive correlation in Canberra, Beijing and Gandhi College
2016年1月至12月,在加德满都博德、北京、甘地学院(位于南亚区,高污染区)、堪培拉和联合国大学盖坦分校(位于东南区,低污染区)等不同地点进行了地基测量。作为气溶胶机器人网络(AERONET)的一部分,该研究利用 CIMEL 太阳光度计获得了季节性和年际性 AOD。数据显示,加德满都(0.45±0.01)、甘地学院(0.45±0.02)和北京(0.85±0.03)的 AOD 值高于其他站点,加德满都属于高海拔地区。分析发现,加德满都(0.45±0.01)、甘地学院(0.45±0.02)、UNC 盖坦(0.28±0.001)和堪培拉(0.06±0.002)的季风前 AOD 值较高。另一方面,北京的季风 AOD 较高(0.85±0.03)。研究发现了导致特定地区 AOD 值较高的各种因素。位于亚洲季风区的北京、甘地学院和加德满都,由于经济活动、车辆、城市化、植被火灾、农作物种植的土地开垦,以及冬季生物质燃烧、供暖需求和砖窑、工厂和车辆污染,气溶胶负荷较高。堪培拉和 UNC Gaitan 的 AOD 值较高,主要原因是生物质燃烧和灰尘。波长越短,AOD 值越高,反之亦然。我们对不同波长的 AOD 和可感知水进行了相关分析,观察到一一对应的关系。在堪培拉,柱状水蒸气(CWV)与 1640 纳米波长的 AOD 有很高的相关性(判定系数,R2 = 0.61),但与甘地学院 1640 纳米波长的 AOD 没有关系(判定系数,R2 = 0)。加德满都和盖坦联合国军司令部上空的 AOD 与可接受水之间存在微弱的负相关,但堪培拉、北京和甘地学院上空的 AOD 与可接受水之间存在正相关。
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引用次数: 0
Exploring topological phase transition in Pt2Hg1−xTlxSe3 探索 Pt2Hg1-xTlxSe3 中的拓扑相变
Pub Date : 2023-11-30 DOI: 10.3126/bibechana.v20i3.58632
Deergh Bahadur Shahi, Dipak Bhattarai, Madhav Prasad Ghimire
The transition from trivial to non-trivial phase in two-dimensional materials are called a topological phase transition (TPT). The Berry phase, non-local string order parameter, and edge states define the topological nature of the system. A newly discovered jacutingaite ma- terial Pt2HgSe3 is a layered material which occurs naturally in the form of minerals. The material can be exfoliated and was predicted as a quantum spin Hall insulator. Here, on the basis of density functional theory and tight-binding calculations, we explore Pt2Hg1−xTlxSe3 (x = 0.25, 0.50, 0.75, 1) to understand the electronic and topological properties. We start with the parent material Pt2HgSe3 wherein Hg is replaced partially with x amount of Tl, to tune the topological phases. From the electronic structure calculations, Pt2HgSe3 is found to be a non-trivial semimetal in it’s bulk. Upon electron doping, the material transforms to strong topological metallic phase. The topological Z2 invariant calculation shows TPT in Pt2Hg1−xTlxSe3 with weak topological insulating state (0;001) for x=0, to strong topological metal (1;000) for x=1, respectively.
二维材料中从三相到非三相的转变被称为拓扑相变(TPT)。贝里相、非局部弦阶参数和边缘状态决定了系统的拓扑性质。新发现的黝帘石材料 Pt2HgSe3 是一种以矿物形式自然存在的层状材料。这种材料可以剥离,并被预测为量子自旋霍尔绝缘体。在此,我们以密度泛函理论和紧密结合计算为基础,探讨了 Pt2Hg1-xTlxSe3 (x = 0.25、0.50、0.75、1),以了解其电子和拓扑特性。我们从母体材料 Pt2HgSe3 开始,用 x 量的 Tl 替代部分 Hg,以调整拓扑相。通过电子结构计算,我们发现 Pt2HgSe3 在其本体中是一种非三价半金属。掺入电子后,该材料转变为强拓扑金属相。拓扑 Z2 不变量计算显示,Pt2Hg1-xTlxSe3 中的 TPT 分别为 x=0 时的弱拓扑绝缘态(0;001)和 x=1 时的强拓扑金属态(1;000)。
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引用次数: 0
Thermodynamic, structural and surface properties of rare earth metallic alloys: Au-La liquid system 稀土金属合金的热力学、结构和表面特性:Au-La 液体体系
Pub Date : 2023-11-30 DOI: 10.3126/bibechana.v20i3.59896
S. K. Yadav
A complete information related to the mixing behaviours of Au alloyed with rare earth metals or lanthanides is very scarce. Therefore, an attempt has been made in this work to compute and study the temperature and concentration dependent thermodynamic, structural and surface properties of Au-La liquid alloy using different theoretical approaches. The thermodynamic properties, such as excess Gibbs free energy of mixing, enthalpy of mixing, excess entropy of mixing and activity of the system were computed using available coefficients of interaction energy parameters in the framework of Redlich-Kister polynomial. Taking these as reference values, model parameters for quasi-lattice model were optimised at 1473 K. The model parameters were then determined at higher temperatures assuming them to be linear temperature-dependent. The thermodynamic and structural properties were then computed in the temperature range 1473 K-1773 K. The surface properties of the system were computed using Bulter’s model using determined values of partial excess Gibbs free energy of its components. Present investigations revealed that the compound forming tendency of the system gradually decreased with increase in temperature of the system.
有关金与稀土金属或镧系元素合金混合行为的完整信息非常稀少。因此,本研究尝试使用不同的理论方法计算和研究金-拉液态合金的热力学性质、结构性质和表面性质与温度和浓度的关系。在 Redlich-Kister 多项式框架内,利用现有的相互作用能参数系数计算了热力学性质,如混合的过量吉布斯自由能、混合焓、混合过量熵和系统的活性。以这些参数为参考值,在 1473 K 时对准晶格模型的模型参数进行了优化。然后计算了 1473 K-1773 K 温度范围内的热力学和结构特性。系统的表面特性是使用 Bulter 模型,利用确定的各组分部分过剩吉布斯自由能值计算得出的。目前的研究表明,随着体系温度的升高,体系形成化合物的趋势逐渐减弱。
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引用次数: 0
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Bibechana
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