Himalayan Journal of Science and Technology

Assessment of physical properties and antimicrobial activity of activated charcoal impregnated with silver nanoparticles against Escherichia coli

2022-12-23T06:52:08+00:00

Activated charcoal possesses small pores that help in the increment of the surface area available for chemical reactions. In this study, coal samples were taken from Kalimati, Dharan, and Eastern Nepal with the goal of determining the antibacterial activity of activated charcoal against Escherichia coli. This study also measured the moisture content, volatile substances, fixed carbon, and pH of coal using proximate analysis. This study was carried out by the activated carbon impregnation with silver nanoparticles by varying with the different AgNO₃ concentrations: a) 0.1 mol/liter (mol/L) b) 1 mol/L c) 1.5 mol/L one at a time. By the proximate analysis, it was found that the moisture content was 2.2%, the volatile matter was 15%, the fixed carbon was 53.8%, and the pH was 5.83. The antimicrobial activity was performed by agar well diffusion methods. With 25 mg nanoparticles the zone of inhibition against E. coli was found to be 7 mm, 8 mm and 10 mm respectively and with 50 mg nanoparticles the zone of inhibition against E. coli was found to be 9 mm, 9 mm and 12 mm with concentration 0.1 mol/L, 1 mol/L and 1.5 mol/L of AgNO₃ respectively. According to Pearson correlation (r = 0.697) and a simple linear regression (R2 = 0.798), there was a positive relationship between the concentration of AgNO₃ and the zone of inhibition observed against E. coli. The highest zone of inhibition (ZOI) of activated charcoal impregnation against E. coli was 12 mm at 1.5 mol/L of AgNO₃ with 50 mg silver nanoparticles, which was comparatively less against seven standard antibiotics (13-29 mm ZOI).

Evaluation of physicochemical and microbiological quality of drinking water in the distribution system of Dharan, Nepal

2022-12-23T09:36:08+00:00

Dharan has been facing drinking water-related problems for a very long time now and this research was conducted in order to determine whether the quality of water being distributed throughout the city was one of them. Hence, 31 samples were taken from the drinking water distribution system of Dharan in the spring of 2022 for evaluating the physicochemical and microbiological quality of drinking water being distributed across the sub-metropolitan city. Though public knowledge and adequate management of watershed and reservoir premises were insufficient, the physicochemical characteristics were determined to be within the National Drinking Water Quality Standards (NDWQS) for drinking water with temperatures ranging from 23.6 °C to 25.6 °C, pH 7.7 to 8.5, conductivity 38.2 to 38.7 µS/cm, Dissolved Oxygen (DO) 7.7 to 9.0 mg/L, Biological Oxygen Demand (BOD) 0.8 to 1.8 mg/L, chloride 29.82 to 34.08 mg/L, nitrite 10 mg/L and ammonia <0.5 mg/L. However, the coliform bacteria levels were significant, with the highest TCC (Total Coliform Count) being 137 CFU/100mL, the highest FCC (Fecal Coliform Count) being 85 CFU/100mL and the highest TPC (Total Plate Count) being TMTC (Too Many To Count). The water was found to be unsafe to drink without disinfection treatments. It may be necessary to carry out treatment procedures like chlorination as advised by WHO (World Health Organization) as soon as possible while also taking into account the proper application of filtration techniques for distributing safe drinking water to the residents of Dharan.

Fabrication of Transparent Thin Film for Application of Thin Film Transistor (TFT) and Microelectronics

2022-12-23T09:49:49+00:00

A thin-film transistor (TFT) is a special type of metal-oxide-semiconductor field-effect transistor (MOSFET) made by coating an insulating substrate with layers of an active semiconductor layer, metallic contacts, and the dielectric layer. FET transistors consist of three main components: source, gate, and drain. The main objective of the work is to fabricate the channel component by growing the ZnO nanostructure on the glass substrate using spin coating and spray pyrolysis methods. Thin films of zinc oxide (ZnO) were deposited on glass substrates by spin coating techniques from a precursor solution containing zinc acetate, ethanol and hydroxide of ammonia. After deposition, the films were centrifuged and evaporated. The application of spray pyrolysis has been used to deposit a wide variety of thin films, which are used in a variety of devices, such as solar cells, sensors and solid oxide fuel cells. It has been observed that the properties of the deposited thin films often depend on the preparation conditions; concentration levels of the precursor solution, coating time, electrical and optical properties of the glass substrate, etc. The average resistance of the sheet of samples F1, F5, F52, and F57 was 8.7 Ω, 9.14 Ω, 8.9 Ω and 9.42 Ω and of the samples, F2, F29, F39, and F53 were 9.5 Ω, 9.3 Ω, 9.9 Ω, 10.0 Ω respectively, at a growth temperature of 340⁰C. The thin films of ZnO were found to be highly transparent between the visible and near-infrared regions of the electromagnetic spectrum and the transmission of each sample decreases with three layers of ZnO seed layer. The decrease in the transmission of the samples confirms the coating of the ZnO seed layer on it. This work has demonstrated that transparent thin films can be fabricated using local techniques developed from locally available materials using less harmful chemical reagents such as zinc acetate. Such fabricated films are optically absorptive and inherently transmissive, further suggesting that they can be used as a channel material in thin film transistors.

Qualitative and Quantitative Analysis of Phytochemical Constituents of Alternanthera brasiliana (L.) Kuntze and Cassia alata (L.) using Different Organic Solvents

2022-12-23T13:06:39+00:00

The therapeutic qualities of Alternanthera brasiliana and Cassia alata are due to the phytochemicals contained in these plants. This research was conducted to study the phytochemical analysis of leaf extracts of these plants using methanol, hexane, and chloroform solvents. The leaves were collected, cleaned, and dried for eight hours at 60°C in a cabinet dryer. Using the solvent extraction method, the extract was made. Qualitative and quantitative analysis was done to determine the occurrence of flavonoids, terpenoids, tannins, phenols, amino acids, alkaloids, phlobatannins, glycosides, and saponins. The extraction yields in methanol, hexane, and chloroform were 15.77%, 3.01%, and 3.16% for A. brasiliana and 26.91%, 19.5%, and 18.32% for C. alata. Alkaloids, terpenoids, tannins, phenols, glycosides, flavonoids, carbohydrates, phlorotannins, and saponins were all found in A. brasiliana. Alkaloids, tannins, phenols, glycosides, flavonoids, carbohydrates, and saponins were found in C. alata. Total phenolic, flavonoid, and tannin content in methanol extract for A. brasiliana were found to be 127.76 mg GAE/g, 136.48 mg GAE/g, and 58.88 mg GAE/g. The total phenolic, flavonoid and tannin content found were 41.76 mg GAE/g, 103.21 mg GAE/g, and 58.67 mg GAE in hexane extract. Similarly, 102.4 mg GAE/g, 112.49 mg GAE/g, and 41.76 mg GAE/g in the chloroform extract. Total phenolic, flavonoid, and tannin content of C. alata in the methanol extract were 36.3 mg GAE/g, 22.43 mg GAE/g, and 10.89 mg GAE/g, in the hexane extract, 25.98 mg GAE/g, 16.68 mg GAE/g, and 3.25 mg GAE/g, in the chloroform extract, 28.52 mg GAE/g, 20.33 mg GAE/g, and 4.56 mg GAE/g. From extraction yields and qualitative and quantitative analysis, methanol was the best solvent.

Extraction, Partial Purification and Utilization of Milk Coagulating Enzyme from Kiwifruit (Actinidia Deliciosa) in Fresh Cheesemaking

2022-12-23T14:13:19+00:00

The study aimed to determine the potential of kiwifruit milk clotting enzyme in cheesemaking. The kiwifruit crude enzyme, extracted with sodium phosphate buffer (pH 7.0), was partially purified by 30-80% ammonium sulfate precipitation. 50% ammonium sulfate saturation exhibited maximum milk clotting activity (MCA), along with 1.56 purification fold, and 78.84% activity recovery. From SDS-PAGE analysis, the partially purified protease showed two bands with a molecular mass of 24 kDa and 23 kDa respectively. The optimum conditions (temperature and pH of milk) for a minimum time of coagulation (TOC) and maximum MCA were determined by response surface methodology (RSM). From the numerical optimization study, the optimum conditions for cheesemaking were pH 6.5 and temperature 55^oC, having 0.94 desirability. The cheese prepared by kiwifruit protease had significantly (p<0.05) higher moisture, ash, calcium content, and yield than rennet cheese, while significantly (p<0.05) lower fat content and acidity were observed in kiwifruit protease coagulated cheese. However, a non-significant (p>0.05) difference in protein content was obtained between both cheeses. This study highlighted that kiwifruit protease has the ability to be used as an efficient milk clotting enzyme in fresh cheesemaking.

Ethnobotanical study of Janachana community forest in Rautahat district, Nepal

2022-12-23T14:51:48+00:00

Community forest user groups (CFUGs) have been receiving different ecosystem services and facilities from the community forest, which are very crucial in their daily life activities. The present study is aimed at identifying the facilities and services received from the different plant species in the Janachana Community Forest, Rautahat district, Nepal. Altogether, 84 members of community forest groups participated in an interview using a semi-structured questionnaire. In total, 65 plants were identified in the study area for use as medicine, firewood, fodder, bedding, food, and other purposes. However, most plants were used as fodder for livestock. Altogether, fifty-eight plant species (89%) were used for multiple purposes (more than one use) and seven (11%) species were used for single purpose. Among the reported plant species, thirty species were used for medicinal purposes. Seeds and leaves were common parts of the plant used as medicine. Most of the plants were used to treat gastritis, cough, and blood clots, which seem to have high prevalence inthe study area. These results imply the various benefits taken by the CFUGs from the community forest in their daily life.

Preparation and shelf-life evaluation of Flaxseed incorporated biscuits

2022-12-23T15:05:29+00:00

Flaxseed incorporated biscuit is a baked, unleavened cake that uses flaxseed flour as the main component. The development of germinated flaxseed incorporated biscuit and the study of its storage stability were the main objectives of this study. Flaxseed was germinated up to 7 days at room temperature. Germination longer than 7 days resulted in significant mold growth. For this study, flaxseed flour was made from the 7- day germinated flaxseed. Five formulations were tasted in a laboratory setting using 0, 12.5, 25, 37.5, and 50 parts germinated flaxseed flour to wheat flour. Design Expert v13 software was utilized to formulate the recipe using D-optimal design. One way ANOVA without blocking was carried out at a 5% level of significance to measure consumer acceptability. According to mean sensory scores, a formulation containing 25 parts flaxseed flour was chosen for further analysis. Acid, peroxide, and moisture values were used to determine the shelf-life of the formulated biscuits. At the end of two months, the values obtained —0.21 mg KOH/g oil, 1.8 MeqO2/kg fat, and 4.88% were within the safer limits. Overall, flaxseed flour incorporation of 25 parts of flaxseed flour was successfully incorporated into the biscuit recipe. Calcium, iron, protein, ash, fiber, and fat were higher in the optimized product than the control.

Effects of various fertilizer combinations on Okra (Abelmoschus esculentus L.) varieties for dietary fiber content and vegetative characteristic

2022-12-23T15:21:07+00:00

A Field experiment using two determinate hybrid varieties of okra (Venus and Nitya) was conducted at Agriculture and Forestry University, Rampur, Chitwan during summer of 2021 to examine the impact of different fertilizer combinations on the dietary fiber content and vegetative characteristics of okra. This study was laid out in a split-plot design and comprised three replications; there were two main plots of Okra varieties, and each main plot contained four sub-plots of fertilizer combinations (Inorganic fertilizer + Poultry manure, Inorganic fertilizer + Vermicompost, Inorganic fertilizer + FYM, and Inorganic fertilizer alone). The experimental results revealed that the Venus variety had a higher dietary fiber content (3.52%) than the Nitya variety (2.98%). Venus variety (6.6 t/ha) had a higher yield as compared to the Nitya variety (5.3t/ha). It was observed that Inorganic fertilizer + Poultry manure (3.80%) followed by Inorganic fertilizer + Vermicompost (3.46 %) had a superior effect on the dietary fiber content of fruit. Inorganic fertilizer + Poultry manure produced the highest plant height (1.13 m), average canopy diameter (1.10 m), and yield (6.8 t/ha), while Inorganic fertilizer + FYM produced the highest pod length (11.81 cm). The results suggest that combined application of a recommended dose of inorganic fertilizer with organic fertilizer (Poultry manure) improves dietary fiber content and vegetative characteristics of the Okra plant .

Phytochemical Screening of Ethnomedicinal Herbal Extracts and their Effect on Microbial Quality of Sukuti

2022-12-23T05:41:32+00:00

The effect of herbal extracts of four ethnomedicinal herbs (Zanthoxylumarmatum, Litsea cubeba, Heracleum nepalense, and Evodia fraxinifolia) of culinary importance on the microbial quality of sukuti (a traditional dried meat product) was studied. Herbal extracts were prepared by grinding each herb to particle size < 250 μm, extracting in 50% (v/v) ethanol, and concentrating in a rotary vacuum evaporator at 50oC. Four of the spoilage and pathogenic microorganisms, viz., Salmonella, Staphylococcus, E. coli, and Lactobacillus were isolated from market sukuti samples and used as test organisms for the study. Herbal extracts at the concentration of 40, 20, 10, and 2 mg/ml were tested against the test organisms to determine the antimicrobial property of the extracts. The herbal extract showing the greatest antimicrobial activity was selected for use in optimized product (sukuti) development. The total phenolic content of the herbal extracts was also determined. The analyses were performed in triplicate. The data were checked for homogeneity before being analyzed with ANOVA in Genstat Release v12. The Fisher's Least Significant Difference (LSD) method was used to compare data means at a 5% level of significance. Zanthoxylum armatum at 40 mg/ml concentration showed the largest zone of inhibition (ZOI) against the test organisms and was therefore selected for final product development. Meat strips (1 cm × 1 cm × 25 cm) were marinated with Zanthoxylum armatum (40 mg/ml) extract at the rate of 2%, aged (24 h at 4 ± 2^oC), and dried in a cabinet dryer for 2 days at 55^oC. The total plate counts (TPCs) of control (untreated)- and herbal (treated) sukuti were carried out for 20 days at an interval of 10 days to determine the microbial stability of the final product. The TPC for the treated sample was significantly lower (p<0.05) than that of the untreated sample.

Electronic and magnetic properties of Half Heusler alloy NiCrSi

2022-12-23T05:56:01+00:00

Utilizing the Quantum Espresso Package and the plane wave pseudopotential approach, the electrical and magnetic characteristics of the Half Heusler alloy NiCrSi have been investigated.Ultrasoft pseudo-potential is used for this calculation. Through our calculation, it was revealed that NiCrSi is a half-metallic ferromagnet in nature with a bandgap of 0.81eV and an effective moment of 2µB respectively. The origin of the gap is mainly due to the covalent band gap and d-d band gap in the system separating bonding states from anti-bonding states. Our calculation predicts a larger spin moment at Cr site than at Ni site which is antiparallel to the moment of Si. The hybridization of Ni- 3d and Cr-4d states can open a minority spin gap at E_f resulting in the semi-conducting nature of the minority spin band.

Hydrogeological Assessment in The Southern Part of Butwal Area, Rupandehi, Nepal

2022-12-23T06:29:14+00:00

Groundwater has been utilized as the major source of water for household, irrigation and industrial purpose. The hydrogeological condition in the Terai region of the Butwal area, Rupandehi district was assessed. The subsurface lithological section and hydro-stratigraphic units of the area within the depth of 80 m were produced using secondary data from borehole lithologs. The study area i.e., quaternary deposit, comprises boulders, cobble, pebble, gravel and another alluvial (river) deposits. Thick and coarse aquifer materials (boulder and gravel) were determined at wells (DW-2,5,8 and 6), that were lying nearby rivers and foothills of Siwalik. While the proportion of finer sediments (sand and clay) was greater in the southern part of the study area. The aquifers in the study area are delineated as unconfined to confined types which are well-recharged primarily through precipitation and surface runoff in the monsoon period. The application of Duba’s Method for groundwater recharge in the study area shows 44 MCM/year. Though the study area is an urban area, the physicochemical parameters like pH, TDS, DO, EC and temperature range within Nepal’s Drinking Water Standard permissible limits. However, as urbanization grows, the quality and quantity may deteriorate in the future, necessitating the adoption of appropriate and sustainable management techniques to safeguard these groundwater resources.