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1
artículo
Publicado 2020
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The Oryza sativahusk is usually discarded and incinerated without control, which is why in the present investigation it was given an alternative use by means of its transformation into different adsorbent materials coded as HRKOH, ACARROZ and ACFeO. (CAC for commercial activated carbon), the activation of the husk was carried out in a chemical way using Caustic Potassium at 40% this to lyse lignocellulosic structures; subsequently, a metal oxide was added chemically. The process was optimized through a multilevel factorial design, the maximum yield was recorded by the HRKOH material and was 94.45%, however, due to its low porosity and consequently low retention of pollutants, it was not considered a competent material., the field tests regarding the adsorption of hydrogen sulfide showed similar behaviors between ACarroz, ACFeO and CAC, so it was decided to contrast the material ACARROZ v...
2
artículo
Publicado 2019
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In this study, a new electrochemical sensor for determination of cyanide is proposed. The sensor is formed by a carbon paste electrode modified with hierarchical porous carbon and silver sulfide nanoparticles. The morphology characterization was performed by transmission electron microscopy (TEM) and scanning electron microscopy (SEM), while the chemical and electrochemistry characterization were performed by energy dispersive X-ray spectroscopy and cyclic voltammetry, respectively. Under the optimized conditions, the Ag2SNPs-HPC300 sensor presented a large concentration linear range of 5.9 × 10−7 to 1.1 × 10-3 mol L-1, and limit of detection of 7.0 × 10-8 mol L-1 using square-wave adsorptive anodic stripping voltammetry (SWAdASV) technique. The analytical response of the Ag2SNPs-HPC300 sensor was evaluated in presence of different compounds, and the results showed a RSD of 4.3% in ...
3
artículo
Publicado 2005
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The behavior of the pressure of a fluid that filters through the wall of a dike, which is supposed to be made of a porous material, leads to the approach of a boundary problem that involves equations in partial derivatives under Dirichlet and Newman type conditions. ; at some borders while at another it is unknown, that is, it leads to a free border problem. For the case that the Irasversal section of the rectangular wall is considered, the problem is associated with a variational inequality and for non-rectangular flat sections, there is a free form problem associated with a quasivariational inequality. The study of the first case is resolved in reference [4]. In the present work we have considered the numerical study of the second case. To solve this problem, a mathematical treatment is made using the theory of duality. later; by calculating fixed-point iterations, such that in each it...
4
artículo
Publicado 2005
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El comportamiento de la presión de un fluido que se filtra a través de la pared de un Dique, el cual se supone es de un material poroso, conduce al planteamiento de un problema de contorno que involucra ecuaciones en derivadas parciales bajo condiciones tipo Dirichlet y Newmann; en algunas fronteras mientras que en otra es desconocida, es decir, conduce a un problema de frontera libre. Para el caso que se considere la sección trasversal de la pared de forma rectangular, el problema está asociado a una inecuación variacional y para secciones planas no rectangulares, se tiene un problema de frontera libre asociado a una inecuación quasivariacional El estudio del primer caso está resuelto en ¡a referencia [4]. En el presente trabajo hemos considerado el estudio numérico del segundo caso. Para resolver este problema, se le hace un tratamiento matemático utilizando la teoría de dua...
5
objeto de conferencia
Publicado 2007
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This work has been financially supported by the International Program for Physical Science of Uppsala University (IPPS), the Instituto de Investigacion of Universidad Nacional de Ingenieria, and CONCYTEC (Peruvian Research Council).
6
tesis de maestría
Publicado 2017
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También agradecer a CIENCIA ACTIVA del Consejo Nacional de Ciencia y Tecnología (CONCYTEC), al programa de Maestría en Universidad Peruanas, al convenio 035-2015 FONDECYT por la beca otorgada para realizar los estudios de Maestría en Química de la PUCP, asimismo, por financiar el presente trabajo de tesis y la participación en el III WORKSHOP ADSORPTION CATALYSIS AND POROUS MATERIALS realizado en Bogotá-Colombia.
7
artículo
Publicado 2020
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Methylmercury (MeHg+) is a mercury species that is very toxic for humans, and its monitoring and sorption from environmental samples of water are a public health concern. In this work, a combination of theory and experiment was used to rationally synthesize an ion-imprinted polymer (IIP) with the aim of the extraction of MeHg+ from samples of water. Interactions among MeHg+ and possible reaction components in the pre-polymerization stage were studied by computational simulation using density functional theory. Accordingly, 2-mercaptobenzimidazole (MBI) and 2-mercaptobenzothiazole (MBT), acrylic acid (AA) and ethanol were predicted as excellent sulfhydryl ligands, a functional monomer and porogenic solvent, respectively. Characterization studies by scanning electron microscopy (SEM) and Brunauer–Emmett–Teller (BET) revealed the obtention of porous materials with specific surface areas...
8
artículo
A novel methodology was employed to prepare new nanocomposites with photocatalytic properties based on Ce-doped TiO2 nanoparticles arranged over a layered silicate. The catalysts were porous materials formed by exfoliated silicate layers surrounded by anatase nanoparticles. In this way, the anatase was doped by different amounts of Ce, yielding to catalysts with light absorption properties on the visible region. The photocatalytic behavior was tested for different reactions: adsorption and photocatalysis, showing outstanding and promising results for the removal of bacteria by using solar light as an energy source. The influence of the physicochemical properties of the catalyst and the reaction parameters will be studied in detail to manage new catalysts for the disinfection of drinking water.
9
artículo
Publicado 2007
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The present study has as main objecuve the search of new materials, among them the porous materials whose diversity of pore diameter confers lO the same specific properties, those that in turn determine a series of applications like adsorbents. catalysts, and shield materials, among others. The investigatíon consists of the synthes1s of macroporous materials by the method Sol-Gel, using reactive of low cost as sodium silicate (silicon source) and includes/understanos the following stages: 1) control of hydrolysis of the inorganic precursors: 2) formatíon oí the rnacrostructure material (hydrothermal synthesis) and 3) elimination of the organic matter by calcinations. The structural characterization and the degree of crystalinidad were made by means of Diffraction of Rays-X (DRX) and Electronic Diffraction of Area Selecta.(DEAS), whereas the morphologic analysis was made through an Ele...
10
artículo
Publicado 2007
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The present study has as main objecuve the search of new materials, among them the porous materials whose diversity of pore diameter confers lO the same specific properties, those that in turn determine a series of applications like adsorbents. catalysts, and shield materials, among others. The investigatíon consists of the synthes1s of macroporous materials by the method Sol-Gel, using reactive of low cost as sodium silicate (silicon source) and includes/understanos the following stages: 1) control of hydrolysis of the inorganic precursors: 2) formatíon oí the rnacrostructure material (hydrothermal synthesis) and 3) elimination of the organic matter by calcinations. The structural characterization and the degree of crystalinidad were made by means of Diffraction of Rays-X (DRX) and Electronic Diffraction of Area Selecta.(DEAS), whereas the morphologic analysis was made through an Ele...
11
artículo
Publicado 2007
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Chemical Spray Pyrolysis Technique and a combination of sol-gel and spray pyrolysis techniques have been used in order to monitor the morphology of metal-oxide-based thin films to be used as functional materials. We can get from specular to rough-porous surfaces according to the physical-chemical conditions of the precursor / spraying solution. We have produced coatings of ZnO-based and NiOx-based coatings from alcoholic and water solution. A single glass, ITO-precoated glass or alumina was used as the substrate. Porous materials of WO3, CuWO4-x and SnO2 have been produced spraying either inorganic or metal alkoxide gels over a hot substrate. Morphology of coatings were evaluated by either SEM or optical measurements.
12
artículo
Publicado 2020
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The non-cohesive granular soils of the Lambayeque region have physical and mechanical characteristics that hinder the design and construction processes of the various infrastructures that run on it, which is why applying calcifying bacteria sought to improve their properties in order to stabilize it. For this process, the inductive method will be used applying the experimentation and knowledge in biotechnology, using samples of SP-type soils extracted within the Lambayeque region and those that were sometimes subjected to various tests in the natural state and applying calcifying bacteria that allow the recognition of results expected. The parameters that affect soil stabilization are: decrease empty spaces, permeability and increased cohesion, which were achieved due to the precipitation of calcium carbonate resulting from the action of calcifying bacteria in the environment where they ...
13
artículo
Publicado 2020
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Methylmercury (MeHg+) is a mercury species that is very toxic for humans, and its monitoring and sorption from environmental samples of water are a public health concern. In this work, a combination of theory and experiment was used to rationally synthesize an ion-imprinted polymer (IIP) with the aim of the extraction of MeHg+ from samples of water. Interactions among MeHg+ and possible reaction components in the pre-polymerization stage were studied by computational simulation using density functional theory. Accordingly, 2-mercaptobenzimidazole (MBI) and 2-mercaptobenzothiazole (MBT), acrylic acid (AA) and ethanol were predicted as excellent sulfhydryl ligands, a functional monomer and porogenic solvent, respectively. Characterization studies by scanning electron microscopy (SEM) and Brunauer–Emmett–Teller (BET) revealed the obtention of porous materials with specific surface areas...
