arvind pathak | Tribhuvan University (original) (raw)

Papers by arvind pathak

Vaijñānika jagat, Jun 18, 2024

Soil fertility is the basis for agriculture, soil acts as a crucial reservoir of plant micronutri... more Soil fertility is the basis for agriculture, soil acts as a crucial reservoir of plant micronutrients including the major elements such as nitrogen and phosphorus which largely determine plant health and crop productivity. The availability of nutrient absorption largely depends on the soil pH and soil moisture content as it affects the soil's chemical, physical, and biological properties and plays a key role in agricultural productivity. In this study, 15 soil samples were collected from Thecho, Gokarna and Pathivara Yangwarak to measure moisture content, soil pH, nitrogen and phosphorus content and 6 samples of fertilizers from the Nepalese market were selected for their nitrogen and phosphorus content. Soil moisture was found in the range of 16.57-28.40 % and soil pH was found in a slightly acidic to nearly neutral with pH value in the range of 6.5-7.0. Nitrogen content was estimated by the Kjeldahl method and phosphorus content was estimated by Olsen's method. Among 15 soil samples, phosphorus in 11 soil samples were found high value, 3 soil samples were found medium value and 1 soil sample were found low value and nitrogen in 5 soil sample were found high, 5 soil samples were found medium and 5 soil samples were found low value. In most of the fertilizers, nitrogen and phosphorus content were found much lower than labeled in the packet.

Scientific World

Wine is an alcoholic beverage made from grapes containing alcohol ranging from 5-15% by volume. W... more Wine is an alcoholic beverage made from grapes containing alcohol ranging from 5-15% by volume. Wine consumption in the Nepalese market is gaining steady growth in recent years. In this study, parameters such as specific gravity, total acidity, pH, percentage of alcohol content, amount of total dissolved solid, presence of furfural, methyl alcohol and heavy metal were selected for analysis of red and white wine with time after the opening of the packet wine at the time interval of 15, 20 and 25 days respectively. An increase in acidity and specific gravity (0.9780-0.9992 g/mL) while decrease in alcohol content (9.54%-8.03% by volume), presence of heavy Iron and Copper found below 0.003 and absence of furfural and methyl alcohol were observed with time. Consumption of wine in controlled amounts could prevent heart disease and circulatory problem. However, excess wine consumption can inhibit new brain cell development and depressive disorders.

BIBECHANA

Red clay contains solid aluminosilicate has been shown to be reactive in the presence of an alkal... more Red clay contains solid aluminosilicate has been shown to be reactive in the presence of an alkaline activator. The addition of coal fly ash and lime has shown improvements in their mechanical and physical properties of the geopolymer products. FTIR analysis and SEM images of the product have shown the formation of aluminosilicate gel in the geopolymeric product. The maximum compressive strength of the geopolymer products GP-RFL was achieved to be 15.92 N/mm2 having water absorption of 10.47 % and bulk density 2.81 g/cm3. These results indicated that geopolymer mortars made from red clay, coal fly ash and lime could be used as an alternative construction material./p> BIBECHANA 19 (2022) 119-126

Nepal Journal of Science and Technology, 2021

Detergents commercially available in the Nepalese market were studied and several parameters such... more Detergents commercially available in the Nepalese market were studied and several parameters such as surface tension, pH, critical micelle concentration, foaming stability test, hard water test, emulsions stability test were performed. Different medium such as ground water (G.W.), tap water (T.W.), distilled water (D.W.) and 5% ethanol in distilled water were selected for this study. The decrease in surface tension and critical micelle concentration (CMC) in ground water, tap water, distilled water and 5% ethanol in distilled water, ease of cleansing action of the detergents in this medium have been found of the following order: 5% ethanol in distilled water > distilled water (D.W.) > tap water (T.W.) > ground water (G.W.). Among the four detergents, the D1 have shown the least surface tension, CMC value, foam collapsing time, the weight of scum formed when treated with hard water. And maximum emulsion stability of the detergent D1 determines good quality detergent.

Scientific World, 2020

The bulk materials include the construction materials such as plaster sand gravel and cement as w... more The bulk materials include the construction materials such as plaster sand gravel and cement as well as raw materials. Asbestos is the naturally occurring magnesium silicate mineral fibers which has high tensile strength, flexibility and resistance to chemicals, high temperature and stress; this is why it has been considered and used in bulk materials. These mineral fibers are needle shaped and can stick to lung tissue when inhaled and cause inflammation and serious health problems such as asbestosis, mesothelioma and lung cancer or internal fibrosis. It can be detected by simple microscopic method using mineral acid and heat treatment. The method would help in quality analysis of asbestos fiber and save from asbestos induced disease and to develop alternative materials of asbestos fiber material.

Nepal Journal of Science and Technology, 2013

Demolition of old houses and construction of new buildings are in peak in urban sectors which gen... more Demolition of old houses and construction of new buildings are in peak in urban sectors which generate a huge amount of construction wastes. These wastes are rich source of alumino-silicate. Geopolymerization can transform a wide range of alumino-silicate materials into building materials with excellent physicochemical properties. Thus, geopolymers have been synthesized from construction wastes such as sand-cement-mixture (SCM), concrete mixture (CM), brick dust (BD), etc using alkali and alkali-silicate as activators. Parameters like alkali concentration (for dissolution of alumino-silicate), ratio of alkali-silicate to construction wastes and curing time were varied to improve the quality of geopolymeric products. The maximum compressive strengths of geopolymeric products obtained from BD, SCM and CM were 60.0, 47.0 and 45.5 MPa respectively. Nepal Journal of Science and Technology Vol. 14, No. 1 (2013) 81-86 DOI: http://dx.doi.org/10.3126/njst.v14i1.8926

Journal of Nepal Chemical Society

Construction is one of the most important activities increasing the demand for Portland cement re... more Construction is one of the most important activities increasing the demand for Portland cement resulting significant amount of CO2 emission, natural resources degradation, and a high amount of energy consumption. The use of geopolymer has been studied as a potential substitute for Portland cement. Geopolymers are environmentally-friendly binding materials that are produced by the polymerization of alumino-silicates in presence of alkali polysilicates forming Si-O-Al bonds, which are used for several building applications. In this study, red and white clays which contain solid alumino-silicate have shown reactive in presence of an alkaline activator. The addition of lime has shown improvement in the mechanical and physical properties of the geopolymer products. The FTIR analysis and SEM images of the product have shown the formation of aluminosilicate gel in the geopolymeric product. The maximum compressive strength of the geopolymer products RCW and RWL were achieved to be 15.91 and...

After the earthquake on April 25, 2015 and its aftershocks a total of 4,784 public and 531,266 pr... more After the earthquake on April 25, 2015 and its aftershocks a total of 4,784 public and 531,266 private buildings were either destroyed or damaged. It generated large wastes that imposed economic burden and contributed to environmental pollution. The alumino-silicate found in such wastes can be used as raw material for the synthesis of geopolymers. Geopolymers have been synthesized from construction waste such as coal fly ash (CFA) and brick dust (BD) using alkali and alkali-silicate as activators. Geopolymerization can transform a wide range of waste alumino-silicate materials into building materials with excellent chemical and physical properties such as fire, acid and earthquake resistance. A maximum compressive strength of 2.21 MPa was obtained with concrete powder treated with 6 M NaOH solution and a maximum compressive strength of 45.4 MPa was obtained with 1.0 mass ratio of Na2SiO3 to construction wastes cured for 28 days at 40°C. The compressive strength of geopolymers initia...

Journal of Nepal Chemical Society, 2013

In this work, geopolymers have been synthesized from coal fly ash (CFA) using KOH and Na2SiO3 as ... more In this work, geopolymers have been synthesized from coal fly ash (CFA) using KOH and Na2SiO3 as activators. Some parameters such as alkali concentration, amount of Na2SiO3 and curing time have been varied in order to improve the quality of geopolymeric product. The geopolymerization process was carried out using 3-8 M KOH solutions, Na2SiO3 to CFA mass ratio of 0.25-2.00 and curing time variation from 6-28 days. The curing temperature was fixed at 40°C in all the cases. During the variation of KOH concentration, the maximum compressive strength of 6.62 MPa was obtained with CFA treated with 7 M KOH solution. Similarly, with the variation of the mass ratio of Na2SiO3 to CFA, the maximum compressive strength of 28.1 MPa was obtained with Na2SiO3 to CFA mass ratio of 1.75. Furthermore, the compressive strength was found to be increased with increasing curing time and 41.9 MPa was achieved with 28 days of curing time. DOI: http://dx.doi.org/10.3126/jncs.v29i0.9232Journal of Nepal Chemi...