Nepal Journal of Science and Technology <p><em>Nepal Journal of Science and Technology</em> is a peer-reviewed open access journal published by Nepal Academy of Science and Technology (NAST). Full text articles are available. </p> Nepal Academy of Science and Technology (NAST) en-US Nepal Journal of Science and Technology 1994-1412 <p>Authors retain copyright and grant the journal right of first publication.</p> Message from the Editor-in-Chief Vol.21(2) <p>No abstract available.</p> Dilip Subba Copyright (c) 2022 The Author(s) 2023-12-31 2023-12-31 21 2 Biology and Life Table of Fall Armyworm Spodoptera Frugiperda (J.E. Smith) on Maize at Laboratory Conditions in Nepal <p>The biology and life table of Spodoptera frugiperda (J.E. Smith) was studied at 27±2 °C temperature and 75±10% relative humidity at a Laboratory in the National Entomology Research Center, Lalitpur, Nepal from June to October, 2021.The main purpose of the study is to determine life cycle and to prepare stage specific life table of the insect on the preferred host maize. The mean incubation, larval and pupal periods were found to be 2.79, 14.04 and 9.49 days, respectively. The adult longevity of male and female moths was recorded at 15.39 days and 16.16 days. Pre-oviposition, oviposition and post-oviposition periods of female moths were 3.27 days, 5.39 days and 6.85 days with the fecundity of 1712 eggs per gravid female. The width of head capsules of the first, second, third, fourth and fifth larval instars was observed to be 0.31 mm, 0.51 mm, 0.81 mm, 1.30 mm and 1.95 mm, respectively. The highest apparent mortality (13.39) and indispensable mortality (10.02) were recorded in the insect’s egg stage. Among larval instars, the maximum apparent mortality (7.1) and indispensable mortality (4.72) were recorded in the first instar.</p> Binu Bhat Ajaya Shree Ratna Bajracharya Copyright (c) 2022 Binu Bhat, Ajaya Shree Ratna Bajracharya 2022-12-31 2022-12-31 21 2 1 8 10.3126/njst.v21i2.62349 Genotypic Variation in Physico-Chemical Properties of Avocado at Dailekh <p>This study was conducted to analyze the physical and chemical properties of the fruits in 16 avocado genotypes in 2020. Fruits were harvested at physiological maturity stage from seed propagated plants and analyzed their physical (fruit weight, fruit length, fruit diameter, pulp weight, pulp/fruit ratio, and seed/fruit ratio) and chemical properties (moisture content, reducing sugar, total soluble solids, crude protein, total ash, phosphorous, iron, calcium, crude fat and crude fiber). The analysis of one-way variance of the data revealed highly significant variation in physico-chemical properties among avocado genotypes. Genotypes HRSDAV05, HRSDAV07, HRSDAV06 and HRDAV03 displayed the lowest seed/fruit ratio of 10.0, 13.5, 14.6 and 16.8%, respectively. Total soluble solid (TSS) content was the highest in HRSDAV08 (6.7 °Brix), HRSDAV03 (6.0 °Brix), HRSDAV07 (6.0 °Brix) and HRSDAV012 (6.0 °Brix). Crude protein was the highest in HRSDAV07 (19.2%), HRSDAV09 (17.8%) and HRSDAV014 (17.4%). HRSDAV03 and HRSDAV012 had the highest total ash content of 6.4% and 5.1%, respectively. Phosphorus content was the highest in HRSDAV03 (235.2 mg/100 g), but iron content was the highest in HRSDAV07 (2.5 mg/100 g). Crude fat and crude fiber were the highest in HRSDAV013 (63.0%) and HRSDAV03 (48.4%), respectively. The analysis of physico-chemical characters of avocado fruits identified HRSDAV03, HRSDAV05, HRSDAV06, HRSDAV07, HRSDAV08, HRSDAV09 and HRSDAV013 as potential parental genotypes for developing new cultivars.</p> Binod Prasad Luitel Copyright (c) 2022 The Author(s) 2022-12-31 2022-12-31 21 2 9 20 10.3126/njst.v21i2.62351 SQL Optimization in Oracle using Hybrid Genetic and Ant Colony Algorithm <p>In this paper, the input user Structured Query Language (SQL) query is converted into an optimized SQL query using a hybrid algorithm. The main aim is to reduce query execution time using PHP language and oracle database. These performance has been evaluated using different performance metrics: Cost of individuals, Query execution time. The hybrid algorithm method combines the evolutionary effect of the Genetic Algorithm (GA) and the cooperative effect of Ant Colony Optimization (ACO). A GA with a great global converging rate aims to produce an initial optimum for allocating initial pheromones of ACO. An ACO with great parallelism and effective feedback is then served to obtain the optimal solution. A fused algorithm of a GA and ACO to solve SQL optimization problems is an innovative solution that presents a clear methodological contribution to the optimization algorithm. In the simulation result, we found the algorithm of a GA and ACO to solve SQL optimization problems in Oracle. It is an innovative solution that presents a clear methodological contribution to the optimization algorithm.</p> Rajan Kusi Kabir Kumar Sinkemana Sanjeeb Prasad Pandey Shashidhar Ram Joshi Copyright (c) 2022 The Author(s) 2022-12-31 2022-12-31 21 2 21 28 10.3126/njst.v21i2.62353 Average Intensity and Wavelength of the Emitted Radiations from Earth Surface with Error Analysis <p>This research finds the spectrum and the net intensity of the emitted radiations from the earth surface at different temperatures of 273, 283, 293, 303, 313, and 323 K. The intensity of the radiations emitted from the surface varies by 272.013 Wm-2 between 273 K and 323 K surface temperatures at emissivity 0.9. The average intensity for emissivity 0.9 is 410.405 Wm<sup>-2</sup>, with a standard deviation of 101.94 Wm<sup>-2</sup> and standard error 41.616. The calculated mean emitted flux is found 8.9482 W/m<sup>2</sup>/sr/µm for 0.9 emissivity. At emissivity of 0.96, the desert emits radiation with an average intensity of 437.77 Wm<sup>-2</sup> having standard deviation 108.708 Wm<sup>-2</sup> and standard error 44.379. These large values of standard deviation and standard error are due to the large difference between any two adjacent values of intensity of the emitted radiations. Standard error comparisons between the emissivity calculations of 0.9 and 0.96 show that the intensity in emissivity 0.9 is more appropriate than the intensity in emissivity 0.96 in determining the average value of intensity of emitted radiations. The difference between the calculated and standard values for the average intensity of radiation radiated from the earth’s surface is about 17%.</p> Rajendra Neupane Hari Ram Krishna Gauli Krishna Bahadur Rai Copyright (c) 2022 The Author(s) 2022-12-31 2022-12-31 21 2 29 46 10.3126/njst.v21i2.62354 Response of Post-Harvest Behavior of Pineapple (Ananas comosus var. Giant Kew) Fruits at Different Storage Conditions <p>The present study was carried out to establish the synergistic effect of CoolBot storage and organic and chemical preservatives on pineapple fruit to lengthen the marketable shelf life. The research work was conducted during the period of 17<sup>th</sup> Mangsir to 28<sup>th</sup>, Poush 2077 at the laboratory of the National Horticulture Research Center, Khumaltar, Lalitpur. The pineapple fruits var.Giant Kew was set up in an experimental unit in a Completely Randomized Design (CRD) with eight treatments and replicated three times. The treatments were viz., T1= Dipped in 3 mM salicylic acid for 15 min. under CoolBot storage, T2= Dipped in 5 mM salicylic acid for 15 min. under cool bot storage, T3= Coated with aloe Vera gel and T4=controlled treatment under CoolBot storage and T5= Dipped in 3 mM salicylic acid for 15 min. under ambient storage, T6= Dipped in 3 mM salicylic acid for 15 min. under ambient storage T7= Coated with aloe Vera gel under ambient storage and T8= Controlled treatment under ambient storage condition. Each replication of treatment comprises 8 fruits. Changes in Cumulative physiological weight loss % (Cum. PLW%), Vitamin C content (mg/100 gm), Outside and inside Firmness (N/F) of fruit, pH value of juice, and sensory evaluation were observed during the storage period at every 7 days of an interval. The samples at ambient storage conditions (20.5°C and 61.6%) were removed on day 14, and samples at CoolBot storage (10-12°C and 90-92%) were removed on 35 days of storage by observing the sensory evaluation. Thus the study concluded that the synergistic effect of aloe Vera gel coating and Cool Bot storage has been found effective in pineapple fruits to delay internal browning index and extend marketable shelf life from 14 days (ambient storage) to 35 days. </p> Mira Dhakal Suprabha Pandey Shandesh Bhattarai Dipendra Ghimire Sujan Subedi Copyright (c) 2022 The Author(s) 2022-12-31 2022-12-31 21 2 47 56 10.3126/njst.v21i2.62355 Recent Trends of Mean Maximum and Minimum Air Temperatures in Bangladesh <p>The annual, seasonal, and monthly maximum and minimum air temperature time series for 34 stations in Bangladesh have been examined during the period 1981– 2020 in this study. Three statistical tests were used in the analysis namely Mann–Kendall, Sen’s slope estimator, and linear regression, respectively. 47% of stations experienced significantly rising maximum air temperature trends during the pre-monsoon, 100% during the monsoon, 74% during the post-monsoon, and 24% during the winter season, respectively. Similar findings have been made about minimum air temperatures during the pre-monsoon, monsoon, post-monsoon, and winter seasons in 41, 91, 41, and 35% of stations over Bangladesh. According to the linear regression technique, the significant increasing trends of the maximum air temperatures at Patuakhali and Mongla stations are 0.83°C/decade and 0.82°C/decade in February and October, respectively. Furthermore, at Sandwip and M. Court, the significant increasing minimum air temperature trends in July and March are 0.26°C/decade and 0.66°C/decade, respectively. The highest monthly maximum and minimum air temperature time series value falls (decreases) were seen in January over the stations at Mongla (-0.58°C/decade) and Sandwip (-0.63°C/decade), respectively. This information will be useful in developing adaptation plans to mitigate the harmful effects of climate change. Vulnerability assessments, disaster management, enhanced structure design, institutional reform, and antiextreme climate engineering are some of the viable climate change adaptation approaches in Bangladesh due to rising temperatures.</p> Mizanur Rahman Hasan Imam Sabuj Roy Farhana Hoque Urmee Ahsan Abubakar Abdullah Copyright (c) 2022 The Author(s) 2022-12-31 2022-12-31 21 2 57 72 10.3126/njst.v21i2.62356 Quantification of Heavy Metal Deposition in Lichen Species of Kathmandu Valley <p>Heavy metal pollution in urban areas is the major concern of every rapidly growing nation. The main aim of this study was to determine the heavy metal concentration around Kathmandu valley using locally growing lichens species. The study was conducted by random sample collection method throughout Kathmandu, at the interval of 2km considering Tri- Chandra College as reference point in four geographical directions based on radial distribution pattern. In this study, we quantified Lead (Pb), Cadmium (Cd), and Chromium (Cr) in <em>Pyxine cocoes, Arthopyrenia sp, Caloplaca sp, </em>and Hypotrachya revolute collected from Kathmandu valley. The samples were subjected to Atomic Absorption Spectroscopy (AAS) for heavy metal determination. High concentrations of heavy metals were detected in areas that experience a high influx of vehicles like the Swayambhu area, Pepsicola area, and Lagankhel area. The areas further away from heavy traffic roads showed a significantly low amount of heavy metal concentration. The study provides an insight into the current state of heavy metals in Kathmandu valley, which in high concentration can be detrimental to the health of living organisms.</p> Salin Maharjan Roshan Sundas Chitra Bahadur Baniya Buddha Bahadur Basnet Nabin Narayan Munankarmi Copyright (c) 2022 The Author(s) 2022-12-31 2022-12-31 21 2 73 80 10.3126/njst.v21i2.62357 Study on Government Managed Gardens in Public Buildings of Kathmandu Valley <p>An area embellished with ornamental plants near the city area and office can give a pleasurable, picturesque and naturalistic effect which creates a refreshing and conducive working environment for both staff and service seekers. A study was carried out to elucidate the existing situation of the government managed gardens in public buildings located in the Kathmandu valley. The gardens were selected purposively and the study was made based on the number of plant species, composition of plants, styles of gardening, maintenance of garden and appreciation of the garden. The maintenance and the appreciation of gardens were evaluated by the Likert scale (1-4). The abundance of tree was higher followed by herbaceous perennial, herbaceous annual, shrub, cacti and succulent. The garden of Narayanhiti Palace Museum was found to be dominant in tree, shrub and herbaceous perennial while the Garden of Singha Durbar and Supreme Court was found to be dominant in herbaceous annual. The frequency of <em>Thuja orientalis </em>(tree), <em>Bougainvillea spp </em>(shrub), <em>Cuphea hyssopifolia </em>(herbaceous perennial), <em>Calendula officinalis </em>(herbaceous annual) and <em>Petunia hybrida </em>(herbaceous annual) were higher. This study shows that formal gardens (66.66%) dominated informal gardens (33.34%). It was found that the maintenance and the overall appreciation of gardens were fair to good. The gardens need improvements in various aspects to make them artistic and beautiful.</p> Nirajan Bhandari Umed Kumar Pun Copyright (c) 2022 The Author(s) 2022-12-31 2022-12-31 21 2 81 92 10.3126/njst.v21i2.62358 Assessment of Ecological Footprint of Urban Squatter and Non-Squatter Settlements: A Case Study of Kathmandu Valley, Nepal <p>This research attempted to understand the variation in the ecological footprint of squatter and non-squatter households in terms of the cumulative environmental behavior index (CEBI). A hybrid footprint measurement tool was built considering the principal factors affecting ecological footprint (EF). The correlation between settlement type (squatter and non-squatter) and the EF (as measured by the mean CEBI) was tested using the Pearson product-moment correlation coefficient. Knowledge, attitude and behavior of people regarding the environment sustainability were studied through questionnaires and field observation. The average CEBI of non-squatter settlements was found to be significantly more than that of squatter settlements. Squatter households in the sample had a statistically significantly lower environmental impact (in terms of energy and water consumption) than non-squatter households (p&lt;0.01). The highest contribution to the total CEBI was from the food sector, followed by waste production. People’s attitudes towards the environmental sustanability varied and most of the squatter households had no clear opinion. Knowledge of environment-friendly practices were found comparatively more in non-squatter households. A majority of the respondents were ignorant about renewable energy. Identification of factors mainly responsible for increasing footprint is needed to design interventions for promoting sustainable development. The findings from this research will be useful for urban planners and other concerned professionals to make amends in sector policies for the sustainable development.</p> <p>&nbsp;</p> Pratistha Pyakure Ramesh Raj Pant Sadhana Pradhanang Kiran Bishwakarma Archana Ghimire Copyright (c) 2022 The Author(s) 2022-12-31 2022-12-31 21 2 93 104 10.3126/njst.v21i2.62359 Study of Structural Properties of Solar Energy Material CH3 NH3 PbX3 (X= I, Br and Cl) Perovskites and its Mixed Halides Using Density Functional Theory <p>The present study has explored the electronic properties of Organic-inorganic mixed halide-based perovskites using density functional theory. The Quantum Espresso simulation package with PBE parameterization within the generalized gradient approximation (GGA) has been used in this work. The findings reveal that the addition of halogens (bromide and chlorine) to compound CH<sub>3</sub>NH<sub>3</sub>PbI<sub>3</sub> for all the possible substituted halides may cause the shifting of energy bands in the band structure and thus change the bandgap. Hence, this calculation may be used to design perovskite solar cell material with varied electronic structure.</p> Sachin Sharma Sanjay Prakash Kaushik Ram-Krishna Thakur Vivek Kumar Shukla Copyright (c) 2022 The Author(s) 2022-12-31 2022-12-31 21 2 105 114 10.3126/njst.v21i2.62360 IoT Based ECG Using AD8232 and ESP32 <p>Good qualities ECG are utilized by physicians for interpretation and diagnosis of cardiovascular diseases. The rural hospitals of Nepal lack necessary equipment and need modern medical devices. This article is about an IoT-based ECG device in which AD8232 is used for the ECG signal acquisition, MATLAB for filtering and ESP32 for processing and communicating with the Internet.&nbsp;</p> Choodamani Bhattarai Siddhartha Kumar Yadav Subash Koirala Copyright (c) 2022 The Author(s) 2022-12-31 2022-12-31 21 2 115 121 10.3126/njst.v21i2.62361