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  Subjects -> SCIENCES: COMPREHENSIVE WORKS (Total: 374 journals)
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Journal of Institute of Science and Technology
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  This is an Open Access Journal Open Access journal
ISSN (Print) 2467-9240
Published by Nepal Journals Online Homepage  [114 journals]
  • Foraging Variation of Bombus species with Plant Families and Floral Colors
           in Chitwan Annapurna Landscape, Nepal

    • Authors: Kishor Chandra Ghimire, Anjeela Pandey, Ganesh Datt Joshi, Daya Ram Bhusal
      Pages: 1 - 10
      Abstract: Little is known about the effect of the type of vegetation and floral color on the foraging behavior of Bombus species.  In this work, we have investigated the differential foraging association of bumblebees (Bombus spp.) with the specific flower color and the plant families in Chitwan-Annapurna Landscape (CHAL). The specimens were collected between April to October 2019 and field visits were carried out by following accessible walking transects between 600 to 3500 m asl covering different habitats of the study area. The bumblebees were collected by opportunistic methods using a sweeping net. We found that the relative frequency of Bombus spp. varied significantly with the families of local flowering plants and the particular colors of flowers. Some of the bumblebees visited at the specific plant family for nectar and pollen indicating the specific association with particular flower morphology and color. This study, therefore, gives an insight into the differential foraging preference of Bombus spp. to certain plant families with selected specific colors in CHAL.
      PubDate: 2022-07-01
      DOI: 10.3126/jist.v27i1.43789
      Issue No: Vol. 27, No. 1 (2022)
       
  • A Brief Survey on the Inverse Galois Problem

    • Authors: Bigyan Adhikari, Tulasi Prasad Nepal
      Pages: 11 - 17
      Abstract: Inverse Galois problem (IGP) states whether any finite group is realizable as a Galois group over the field K. It is the question of the structure and representation of the Galois group and also questions its epimorphic images. So, it is called an inverse Galois problem. For K=ℚ (the field of rational number), it is called a classical inverse Galois problem (CIGP). This paper reviews the positive answer to the classical inverse Galois problem (CIGP) for all finite abelian groups and some finite non-abelian solvable groups. We also discuss this problem (CIGP) for some finite non-solvable groups in this paper. This problem still remains to solve, but if we find the true value of the statement ‘All subgroups of order m of the symmetric group (Sm) for all m are realizable as Galois group over ℚ’ then its truth value gives the answer of CIGP. We check this statement for m=1,2,3,4 and 5 in this paper, where we get that this statement is true. If this statement is true, then CIGP has a positive answer. But if this statement is false then CIGP has a negative answer.
      PubDate: 2022-07-01
      DOI: 10.3126/jist.v27i1.40543
      Issue No: Vol. 27, No. 1 (2022)
       
  • The Law of the Iterated Logarithm

    • Authors: Santosh Ghimire, Hari Thapa
      Pages: 19 - 25
      Abstract: The article begins first with the history and the development of the law of the iterated logarithm, abbreviated LIL. We then discuss the LIL in the context of independent random variables, dyadic martingales, lacunary trigonometric series, and harmonic functions. Finally, we derive a LIL for a sequence of dyadic martingales.
      PubDate: 2022-07-01
      DOI: 10.3126/jist.v27i1.45505
      Issue No: Vol. 27, No. 1 (2022)
       
  • Characterization of Essential Oil, Estimation of Phenolic and Flavonod
           Content and Biological Activities of Ephedra pachyclada BOISS

    • Authors: Lekha Nath Khanal, Khaga Raj Sharma, Yuba Raj Pokharel, Surya Kant Kalauni
      Pages: 27 - 35
      Abstract: The northern areas of Nepal are rich in biodiversity and contain a large number of medicinal plant species including the Genus Ephedra of evergreen gymnosperm, belonging to the family Ephedraceae. The plants have been used by the peoples of the Himalayan region for the treatment of asthma, blood pressure, and gastritis for many years. This study was aimed for the evaluation of phytochemical, antioxidant, and antimicrobial activities of methanol, ethyl acetate, dichloromethane, and n-hexane extracts, and gas chromatography-mass spectrometry (GCMS) profiling of the essential oil of the aerial parts of Ephedra pachyclada Boiss from Mustang district of Nepal. Antioxidant activity was evaluated by 2,2-dipheny-1-picrylhydrazyl (DPPH) free radical scavenging assay and antimicrobial activity by the agar well diffusion method. Total phenolics and total flavonoid content were determined by Folin-Ciocalteu and aluminum chloride colorimetric method, respectively. The methanol extract contained the highest total phenolic content of 54.42 ± 1.40 mg GAE/g followed by the ethyl acetate (46.84 ± 0.62 mg GAE/g), DCM extract (19.58 ± 0.24 mg GAE/g), and the lowest TPC was shown for n-hexane extract (5.21 ± 1.40 mg GAE/g) of the dry weight. The methanol extract showed the maximum TFC of 33.28 ± 0.48 mg QE/g, followed by ethyl acetate extract (31.73 ± 0.52 mg QE/g), DCM extract (31.64 ± 0.56 mg QE/g), and the least value was obtained for the n-hexane extract (21.44 ± 2.91 mg QE/g). The methanol extract showed the highest antioxidant activity with a half-maximal inhibitory concentration (IC50) of 37.81 ± 2.24 μg/mL. The methanol extract showed potent activity against Escherichia coli (ATCC 25922), and Staphylococcus aureus (ATCC 25923) with zones of inhibition of 13 mm and 12 mm respectively. Ethyl acetate extract showed a slight potency against Staphylococcus aureus (ATCC 25923) with a zone of inhibition of 9 mm. The essential oil contained diisooctyl phthalate (46.90%), dodecane, 2,6,11-trimethyl-(16.35%), dodecane, 4,6-dimethyl- (11.59%), tetrapentacontane (11.56%), and myrtenol (4.37) as the major compounds. The plant exhibited significant antioxidant and antimicrobial activities which could be used as the source to isolate the active natural antioxidant and antimicrobial agent as the drug candidate in the future drug discovery process.
      PubDate: 2022-07-01
      DOI: 10.3126/jist.v27i1.40590
      Issue No: Vol. 27, No. 1 (2022)
       
  • An Initial Spatiotemporal Assessment of COVID-19 Clusters in Nepal

    • Authors: Bipin Kumar Acharya, Samir Kumar Adhikari, Shreejana Pandit, Basanta Kumar Neupane, Binod Kumar Paudel, Laxman Khanal
      Pages: 37 - 49
      Abstract: Nepal has been strongly influenced by the COVID-19 pandemic and struggling to contain it with multiple interventions. We assessed the spatiotemporal dynamics of COVID-19 in the context of various restrictions imposed to contain the disease transmission by employing prospective spatiotemporal analysis with SaTScan statistics. We explored active and emerging disease clusters using the prospective space-time scanning with the Discrete Poisson model for two time periods using COVID-19 cases reported to the Ministry of Health and Population (MoHP), Government of Nepal during 23 January – 21 July, and 23 January – 29 November 2020 taking the cutoff date of 21 July (end date of nationwide lockdown). The results revealed that COVID-19 dynamics in the early transmission stage were slower and confined to a few districts. However, since the third week of April, transmission spread rapidly across the districts of Madhesh and Sudurpaschim Provinces. Despite nationwide lockdown, nine statistically significant active and emerging clusters were detected between 23 January and 21 July 2020, whereas seven emerging clusters were observed for an extended period to 29 November. After lifting the nationwide lockdown, COVID-19 clusters developed had a many-fold higher relative risk than during the lockdown period. The most likely cluster was located in the capital city, the Kathmandu valley, making it the highest-risk active cluster since August. Movement restriction appears to be the most effective non-pharmaceutical intervention against the COVID-19 in countries with limited health care facilities. Our findings could be valuable to the health authorities within Nepal and beyond to better allocate resources and improve interventions on the pandemic for containing it efficiently.
      PubDate: 2022-07-01
      DOI: 10.3126/jist.v27i1.42652
      Issue No: Vol. 27, No. 1 (2022)
       
  • Mass Transfer Effects on Mixed Convective MHD Flow of Second Grade Fluid
           

    • Authors: Bharat Keshari Swain, Rabi Narayan Barik
      Pages: 51 - 67
      Abstract: An attempt is made to study an unsteady, two-dimensional, laminar, mixed convective Magnetohydrodynamic (MHD) flow of an incompressible visco-elastic fluid (Waltersfluid model) past an infinite vertical plate. The reduced governing equations are solved analytically using two-term harmonic and non-harmonic functions. The effects of different pertinent parameters are discussed with the help of graphs and tables. The novelty of the present study is to account for the effects of viscous and joules dissipative heat and a linear first-order chemical reaction of diffusive species and mixed convective flow phenomena on an infinite vertical plate subjected to time-dependent suction velocity and a transverse magnetic field acting at a distance. The important findings reported herein are: increasing values of chemical reaction parameter cause low velocity and concentration, a decline in concentration profile is seen for the higher values of Schmidt number, Prandtl number contributes to more active convection. The application of the present study may be seen in combustion systems, nuclear reactors, and chemical processes. Before concluding the considered problem, our results are validated with previous results and are found to be in good agreement.
      PubDate: 2022-07-01
      DOI: 10.3126/jist.v27i1.45510
      Issue No: Vol. 27, No. 1 (2022)
       
  • Review on the Different Processes of Urea Production for Achieving
           Sustainable Development Goals in Nepal

    • Authors: Yuvraj Chaudhary, Saswat Gautam, Axit Raj Poudyal, Rajendra Joshi, Bibek Uprety
      Pages: 69 - 81
      Abstract: Infrastructural development in agriculture will directly help achieve sustainable development goals (SDGs) in the least developed countries (LDCs) as the majority of the population in these regions depend on agriculture. This study presents the case of Nepal, one of the LDCs and suggests the establishment of a urea manufacturing plant for improving agriculture productivity and fulfilling the SDGs of zero hunger, no poverty and decent work, and economic growth. Herein, in the context of Nepal, we have reviewed: (i) the status of SDGs of Nepal, (ii) agricultural productivity associated with usage and supply of urea, (iii) technologies associated with urea production, (iv) the feasibility of establishing a urea plant based on the raw material availability and sustainability and (v) the opportunity for economic and technological development. The hydropower-powered electrolysis and CO2 capture from cement industry flue gas were determined to be the strategically feasible and sustainable pathway for urea production and consequently, the fulfillment of SDGs in the context of Nepal. A detailed project study on the economics of the electrolysis-based urea manufacturing process is recommended to foster a sustainable development national plan for Nepal. Although this report highlights the various aspects of urea production in Nepal, this study can be useful for other LDCs dependent on agriculture to achieve SDGs.
      PubDate: 2022-07-01
      DOI: 10.3126/jist.v27i1.45515
      Issue No: Vol. 27, No. 1 (2022)
       
  • Electronic, Thermodynamic Properties, Nonlinear Optical Responses, and
           Molecular Docking Studies on Cephalexin

    • Authors: Tarun Chaudhary, Bhawani Datt Joshi
      Pages: 83 - 92
      Abstract: The topology analysis of electron localization function (ELF), localized orbital locator (LOL), the study of nonlinear optical properties, thermal properties, and biological activities of cephalexin have been performed using DFT/B3LYP and employing 6-311++G(d,p) basis sets. The Mulliken atomic charge on atoms has been calculated. The quantities describing nonlinear optical (NLO) properties like molecular polarizability (α), first hyperpolarizability (β), and second hyperpolarizability (γ) were comparable to the values of urea. The computed value of the second hyperpolarizability was found to be negative, which is an important feature for the system of controllable NLO devices. The thermodynamic properties like heat capacity (S), enthalpy (H), and entropy (S) are positively correlated with the temperature. Further, the title molecule shows good potentiality for binding with the selected target protein matrix metalloproteinase-2.
      PubDate: 2022-06-30
      DOI: 10.3126/jist.v27i1.46361
      Issue No: Vol. 27, No. 1 (2022)
       
  • Ant Genus Tetraponera SMITH, 1852 In Nepal, with Two New Records and Keys
           to Workers (Formicidae: Psueudomyrmecinae)

    • Authors: Indra Prasad Subedi, Prem Bahadur Budha, Vasanta Kumar Thapa
      Pages: 93 - 99
      Abstract: Tetraponera Smith, 1852 is one of the least studied ant genera in Nepal, with only four known species. A taxonomic study was carried out on Nepalese Tetraponera collected mostly from forested habitats ranging in elevation from 98 to 1400 m above sea level using pitfall trapping, baiting, beating low vegetation and hand collecting. The study reports four species – Tetraponera aitkenii (Forel, 1902) and T. difficilis (Emery, 1900) of nigra group as the first record, and T. allaborans (Walker, 1859) of allaborans group, and T. rufonigra (Jerdon, 1851) of rufonigra group as new distribution records for Nepal bringing the total number of known species to six. Taxonomic as well as distribution notes for all four species recorded in this study, and a distribution map of all Nepalese species, are provided. An identification key for Nepalese Tetraponera workers is also presented.
      PubDate: 2022-06-30
      DOI: 10.3126/jist.v27i1.46661
      Issue No: Vol. 27, No. 1 (2022)
       
  • An FPTAS for Quickest Multi-commodity Contraflow Problem with Asymmetric
           Transit Times

    • Authors: Shiva Prakash Gupta, Tanka Nath Dhamala
      Pages: 101 - 107
      Abstract: One of the challenges in operations research is to route numerous commodities from particular supply locations to the corresponding demand points across the lanes of a network infrastructure while maintaining capacity restrictions. The quickest multi-commodity flow problem would be one of those that reduces the time it takes to complete the process. Reorienting lanes toward demand sites can increase outbound lane capacity. The quickest multi-commodity contraflow problem is NP-hard computationally. We use a ∆-condensed time-expanded graph to propose an FPTAS for this problem by including the lane reversal technique. We look into asymmetric transit times on anti-parallel arcs to address the unequal road conditions and flow dependency.
      PubDate: 2022-06-30
      DOI: 10.3126/jist.v27i1.46666
      Issue No: Vol. 27, No. 1 (2022)
       
  • On the Partition of Fast Escaping Sets of a Transcendental Entire Function

    • Authors: Bishnu Hari Subedi
      Pages: 109 - 112
      Abstract: For a transcendental entire function f, the set of form I ( f ) = {z ∈  : (z) → ∞  as n → ∞} is called an escaping set. The major open question in transcendental dynamics is the conjecture of Eremenko, which states that for any transcendental entire function f, the escaping set I ( f ) has no bounded component. This conjecture in a special case has been proved by defining the fast escaping set A ( f ), which consists of points that move to infinity as fast as possible. Very recent studies in the field of transcendental dynamics have concentrated on the partition of fast escaping sets into maximally and non-maximally fast escaping sets. It is well known that a fast escaping set has no bounded component, but in contrast, there are entire transcendental functions for which each maximally and non-maximally fast escaping set has uncountably many singleton components.
      PubDate: 2022-06-30
      DOI: 10.3126/jist.v27i1.46683
      Issue No: Vol. 27, No. 1 (2022)
       
  • Statistical Properties and Applications of Exponentiated Inverse Power
           Cauchy Distribution

    • Authors: Laxmi Prasad Sapkota
      Pages: 113 - 123
      Abstract: In this article, we have introduced the new distribution named exponentiated inverse power Cauchy distribution, which presents more flexibility in modeling a real lifetime dataset. The proposed distribution is analytically appealing and easy to work with and can be used efficiently to analyze the real data sets. Its probability density function can include various shapes according to the value of the parameters. Different explicit expressions for its quantile, survival, hazard and generating function, density function of the order statistics, cumulative hazard function, and failure rate function are provided. The model’s parameters are estimated by using the maximum likelihood estimation method, and we also obtained the observed information matrix. We have also constructed the asymptotic confidence intervals for the estimated parameters of the proposed distribution. We have illustrated the goodness-of-fit test and the application of the purposed distribution empirically through a real-life data set. All the computations are performed in R software (version 4.1.1). It is observed that the proposed distribution gets at least similar or a better fit than some selected distributions taken for comparison.
      PubDate: 2022-06-30
      DOI: 10.3126/jist.v27i1.46685
      Issue No: Vol. 27, No. 1 (2022)
       
  • Modified Inverse NHE Distribution: Properties and Application

    • Authors: Arun Kumar Chaudhary, Laxmi Prasad Sapkota, Vijay Kumar
      Pages: 125 - 133
      Abstract: We have defined a modified form of the inverse NHE distribution in this study. The suggested distribution's hazard function might be shaped like a constant or increasing. Some of the suggested distribution's statistical properties are all clearly derived. Maximum likelihood, Least squares, and Cramer-Von-Mises methods are applied to determine the novel distribution's parameters. For estimators, the asymptotic confidence intervals have been determined as well. The fit of the new distribution is evaluated using an actual data set. We've found that the suggested distribution has proven to be effective in modeling real data set.
      PubDate: 2022-06-30
      DOI: 10.3126/jist.v27i1.46695
      Issue No: Vol. 27, No. 1 (2022)
       
  • Sensing Characteristics of ZnO Nanoparticle Film towards Acetone

    • Authors: Dinesh Kumar Chaudhary, Yogesh Singh Maharjan, Sharmila Pradhan Amatya, Shankar Prasad Shrestha, Rajendra Parajuli, Pitamber Shrestha, Leela Pradhan Joshi
      Pages: 135 - 140
      Abstract: Over the past few decades, nanomaterials of metal oxide such as zinc oxide (ZnO) have been significantly researched for sensing various toxic gases like ethanol, acetone and ammonia. The sensing performance of semiconducting materials depends primarily on their surface structure and the interaction behavior with target gas molecules. The surface quality of ZnO is highly influenced by deposition methods. Although several ZnO surfaces have been rigorously studied for detecting gas leakages, it still possesses drawbacks such as high operating temperature, slow response and recovery times. Henceforth, this investigation was carried out to resolve these issues in the fabrication of future ZnO-based gas sensors. In this work, we report the major findings of the ZnO-based nanoparticle film gas sensor prepared by a doctor blade method to gain insight towards detecting various concentrations of acetone gas at different temperatures. The XRD and FTIR results confirmed the phase purity of ZnO. The results showed the highest response ratio of 25.697 0.012 at 285 oC with an exposure of 800 ppm of acetone along with the quick response and recovery times of 39 sec and 79 sec, respectively. This operating temperature was found to be lower than the reported value for a similar system than that prepared via different methods.
      PubDate: 2022-06-30
      DOI: 10.3126/jist.v27i1.40866
      Issue No: Vol. 27, No. 1 (2022)
       
  • Attention based Recurrent Neural Network for Nepali Text Summarization

    • Authors: Bipin Timalsina, Nawaraj Paudel, Tej Bahadur Shahi
      Pages: 141 - 148
      Abstract: Automatic text summarization has been a challenging topic in natural language processing (NLP) as it demands preserving important information while summarizing the large text into a summary. Extractive and abstractive text summarization are widely investigated approaches for text summarization. In extractive summarization, the important sentence from the large text is extracted and combined to create a summary whereas abstractive summarization creates a summary that is more focused on meaning, rather than content. Therefore, abstractive summarization gained more attention from researchers in the recent past. However, text summarization is still an untouched topic in the Nepali language. To this end, we proposed an abstractive text summarization for Nepali text. Here, we, first, create a Nepali text dataset by scraping Nepali news from the online news portals. Second, we design a deep learning-based text summarization model based on an encoder-decoder recurrent neural network with attention. More precisely, Long Short-Term Memory (LSTM) cells are used in the encoder and decoder layer. Third, we build nine different models by selecting various hyper-parameters such as the number of hidden layers and the number of nodes. Finally, we report the Recall-Oriented Understudy for Gisting Evaluation (ROUGE) score for each model to evaluate their performance. Among nine different models created by adjusting different numbers of layers and hidden states, the model with a single-layer encoder and 256 hidden states outperformed all other models with F-Score values of 15.74, 3.29, and 15.21 for ROUGE-1 ROUGE-2 and ROUGE-L, respectively.
      PubDate: 2022-06-30
      DOI: 10.3126/jist.v27i1.46709
      Issue No: Vol. 27, No. 1 (2022)
       
 
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