Publications by authors named "Vinay kumar Jha"

Article Synopsis
  • Construction and demolition waste is the largest waste by volume, posing a threat to sustainable development and the environment, with potential for recycling into building materials.
  • This study focuses on synthesizing geopolymers from brick powder using metakaolin and lime as additives, testing their compressive strengths, which showed notable increases when these additives were included.
  • The resulting geopolymer product GP-3 demonstrated superior bulk density and mechanical strength, highlighting its promising applications in the construction industry for environmental conservation.
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The scope of this study was to modify the natural clinoptilolite zeolite available locally (Akita Prefecture, Japan) for its ammonium ions retention capacity. The natural clinoptilolite was modified chemically and mechanically with changing time duration of sodium hydroxide treatment and ball to powder mass ratio in wet ball milling, respectively. The ammonium ions retention capacity of thus obtained modified clinoptilolites were found to sharply increase with either increasing alkaline metal cations content or increasing specific surface area (decreasing particle size) of the clinoptilolite.

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Zeolitic materials have been prepared from coal fly ash as well as from a SiO(2)-Al(2)O(3) system upon NaOH fusion treatment, followed by subsequent hydrothermal processing at various NaOH concentrations and reaction times. During the preparation process, the starting material initially decomposed to an amorphous form, and the nucleation process of the zeolite began. The carbon content of the starting material influenced the formation of the zeolite by providing an active surface for nucleation.

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Composite materials of activated carbon and zeolite have been prepared successfully by activating coal fly ash (CFA) by fusion with NaOH at 750 degrees C in N(2) followed by hydrothermal treatments under various conditions. Uptake experiments for Ni(2+), Cu(2+), Cd(2+) and Pb(2+) were performed with the materials thus obtained from CFA. Of the various composite materials, that were obtained by hydrothermal treatment with NaOH solution (ca.

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Steel-making slag, a waste by-product of the Steel Industry, constitutes a major disposal problem. In the present study, excellent adsorbent materials for reducing eutrophication in wastewaters have been prepared from this slag. Heated samples of acid-treated slag and mixtures of slag with kaolinite and Al(OH)(3) were examined to determine their uptake capacities for NH(4)(+) and PO(4)(3-) from aqueous solutions.

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A 67 years old man attended surgery OPD of Nepal Medical College and Teaching Hospital with complain of multiple painless swelling all around the body gradually increasing in numbers for last 15 years. Symptomatically some lumps were becoming large, covering skin of those swelling were sloughing with ulceration. Symptomatic lumps were excised.

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This study concerns with the utilization of waste paper sludge, which contains mainly cellulose fibers and inorganic fillers together with coating materials such as calcite, kaolinite and talc. Paper sludge was fired at 500-900 degrees C for 6 h. The crystalline phases originally present decomposed at increasing temperatures (up to 800 degrees C) in the order kaolinite < calcite < talc.

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Uptake properties of Ni2+ were examined for unmilled and milled paper sludge calcined at various temperatures to develop a new usage of waste paper sludge. Since paper sludge mainly consists of cellulose ([C6H(10)O5]n) fibers, calcite (CaCO3), kaolinite (Al2Si2O5(OH)4) and talc (Mg3Si(4)O(10)(OH)2), amorphous and crystalline CaO(MgO)-Al(2)O(3)-SiO(2) compounds are formed by calcining paper sludge. Wet and dry milling treatments were performed to accelerate solid-state reaction to form the above mentioned target compounds.

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A series of nCaO.Al2O3.2SiO2 samples (n=1-4) were prepared by solid-state reaction of mechanochemically treated mixtures of kaolinite and calcite fired at 600-1000 degrees C for 24 h.

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