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1.
Int J Equity Health ; 20(1): 195, 2021 08 30.
Artículo en Inglés | MEDLINE | ID: mdl-34461914

RESUMEN

BACKGROUND: In India the number of registered deaths increased substantially in recent years, improving the potential of the civil registration and vital statistics (CRVS) system to be the primary source of mortality data and providing more families of decedents with the benefits of possessing a death certificate. This study aims to identify whether inequalities in the completeness of death registration between states in India, including by sex, have narrowed during this period of CRVS system strengthening. METHODS: Data used in this study are registered deaths by state and year from 2000 to 2018 (and by sex from 2009 to 2018) reported in the Civil Registration Reports published by the Office of Registrar General of India. Completeness of death registration is calculated using the empirical completeness method. Levels and trends inequalities in completeness are measured in each state a socio-economic indicator - the Socio-Demographic Index (SDI). RESULTS: Estimated completeness of death registration in India increased from 58% in 2000 to 81% in 2018. Male completeness rose from 60% in 2009 to 85% in 2018 and was much higher than female completeness, which increased from 54 to 74% in the same period. Completeness remained very low in some states, particularly from the eastern (e.g. Bihar) and north-eastern regions. However, in states from the northern region (e.g. Uttar Pradesh) completeness increased significantly from a low level. There was a narrowing of inequalities in completeness according to the SDI during the period, however large inequalities between states remain. CONCLUSIONS: The increase in completeness of death registration in India is a substantial achievement and increases the potential of the death registration system as a routine source of mortality data. Although narrowing of inequalities in completeness demonstrates that the benefits of higher levels of death registration have spread to relatively poorer states of India in recent years, the continued low completeness in some states and for females are concerning. The Indian CRVS system also needs to increase the number of registered deaths with age at death reported to improve their usability for mortality statistics.


Asunto(s)
Certificado de Defunción , Sistema de Registros , Femenino , Humanos , India/epidemiología , Masculino , Sistema de Registros/normas
2.
Crit Rev Biotechnol ; 33(1): 81-96, 2013 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-22676042

RESUMEN

Lipase (triacylglycerol acylhydrolase) is a unique enzyme which can catalyze various types of reactions such as hydrolysis, esterification, alcoholysis etc. In particular, hydrolysis of vegetable oil with lipase as a catalyst is widely studied. Free lipase, lipase immobilized on suitable support, lipase encapsulated in a reverse micelle and lipase immobilized on a suitable membrane to be used in membrane reactor are the most common ways of employing lipase in oil hydrolysis. Castor oil is a unique vegetable oil as it contains high amounts (90%) of a hydroxy monounsaturated fatty acid named ricinoleic acid. This industrially important acid can be obtained by hydrolysis of castor oil. Different conventional hydrolysis processes have certain disadvantages which can be avoided by a lipase-catalyzed process. The degree of hydrolysis varies widely for different lipases depending on the operating range of process variables such as temperature, pH and enzyme loading. Immobilization of lipase on a suitable support can enhance hydrolysis by suppressing thermal inactivation and estolide formation. The presence of metal ions also affects lipase-catalyzed hydrolysis of castor oil. Even a particular ion has different effects on the activity of different lipases. Hydrophobic organic solvents perform better than hydrophilic solvents during the reaction. Sonication considerably increases hydrolysis in case of lipolase. The effects of additives on the same lipase vary with their types. Nonionic surfactants enhance hydrolysis whereas cationic and anionic surfactants decrease it. A single variable optimization method is used to obtain optimum conditions. In order to eliminate its disadvantages, a statistical optimization method is used in recent studies. Statistical optimization shows that interactions between any two of the following pH, enzyme concentration and buffer concentration become significant in presence of a nonionic surfactant named Span 80.


Asunto(s)
Reactores Biológicos , Biotecnología/métodos , Aceite de Ricino/química , Lipasa/química , Aceite de Ricino/metabolismo , Hidrólisis , Lipasa/metabolismo , Tensoactivos
3.
RSC Adv ; 10(26): 15514-15522, 2020 Apr 16.
Artículo en Inglés | MEDLINE | ID: mdl-35495426

RESUMEN

A highly efficient and low-cost alumina-silica nano-sorbent was fabricated and characterized to understand the key factors responsible for its superiority over the existing adsorbents in treating the industry-discharged wastewater for the removal of dyes and heavy metals. As compared to the properties of raw fly ash, the following fundamental improvements were observed for the alumina-silica nano-sorbent: (a) transformation of throttled mesopores into slit-type pores, (b) increment in the surface area by 65-fold, (c) change in the morphology from spherical particles to a flake-type structure with sharp edges, (d) reduction in the average crystal size from 61.143 to 27.176 nm, and (e) increase in the pore volume from 0.005 to 0.50 cm3 g-1. These desired properties of the nano-sorbent were obtained by blending a waste aluminium foil with fly ash. This process increased the ratio of alumina to silica from 0.59 : 1 to an optimum ratio of 1.9 : 1, beyond which the particles agglomerated and the pore volume reduced. Eventually, the precipitated hydroxides were calcined at 700 °C that favoured the formation of γ-alumina. Moreover, this heat treatment changed its crystallinity and morphology of γ-alumina, which abruptly enhanced its activity towards the pollutants. The obtained product (nano-sorbent) was tested for the removal of lead and malachite green from a model wastewater solution over a wide range of initial pollutant concentrations and adsorbent dosages. After observing almost complete removal capacity and reusability for the pollutants, we propose this synthesized adsorbent as a universal material for treating industrial wastewater.

4.
J Nanosci Nanotechnol ; 19(11): 7487-7492, 2019 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-31039917

RESUMEN

Synthesis of silver nanoparticles embedded on calcium alginate film and the catalytic property of this film in the reduction of nitrobenzene with sodium borohydride are demonstrated in this work. Natural polymer alginate acts as effective reducing and stabilizing agent in synthesis of silver nanoparticles. Effect of different parameters on the preparation of silver nanoparticles, such as, temperature, concentration of silver precursor and heating time was investigated. As-prepared silver nanoparticles were characterized by transmission electron microscopy, scanning electron microscopy, UV-Vis spectrometry, and atomic absorption spectrometry. Transmission electron microscopy analysis con-firms the formation of silver nanoparticles with particles size range of 3-19 nm and average particle size was found to be 10±4 nm. Effect of concentration of nitrobenzene and sodium borohydride, catalyst loading and temperature on the catalytic reduction of nitrobenzene was studied. Reusability of catalyst was examined in this reduction reaction and the catalyst shows good activity up to 10th run.

5.
Chem Commun (Camb) ; 55(33): 4825-4828, 2019 Apr 18.
Artículo en Inglés | MEDLINE | ID: mdl-30946389

RESUMEN

We have demonstrated the development of a novel polyxometalate compound, FePW12O40, for photocatalytic degradation of amphetamine and electrocatalytic oxygen evolution. It showed robust optoelectronic properties, which can be attributed to numerous electron trapping sites created by atomic level defects in the microflower-like architecture.

6.
Spectrochim Acta A Mol Biomol Spectrosc ; 61(11-12): 2539-42, 2005 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-15978865

RESUMEN

Interaction between 3d-transition metal ions (Mn2+, Fe2+, Fe3+, Co2+, Ni2+, Cu2+ and Zn2+) and the E(T)(30) dye, 2,6-diphenyl-4-(2,4,6-triphenyl 1-pyridino)phenolate in aqueous medium have been studied by distributing the dye between the aqueous and micellar phase formed by cationic surfactant cetyltrimethylammonium bromide(CTAB). Values of equilibrium constant K for the dye-metal ion interaction and the partition coefficient of the dye between the micellar and the aqueous phase have been determined. K values show a systematic correlation with ionic potential of metal ions.


Asunto(s)
Colorantes/química , Metales Pesados/química , Micelas , Fenoles/química , Piridinas/química , Iones/química , Estructura Molecular , Espectrofotometría , Termodinámica
7.
Environ Sci Pollut Res Int ; 20(5): 3322-30, 2013 May.
Artículo en Inglés | MEDLINE | ID: mdl-23097071

RESUMEN

The adsorption of Pb(II) onto the surface of microwave-assisted activated carbon was studied through a two-layer feedforward neural network. The activated carbon was developed by microwave activation of Acacia auriculiformis scrap wood char. The prepared adsorbent was characterized by using Brunauer-Emmett-Teller (BET) surface area analyzer, scanning electron microscope (SEM), and X-ray difractometer. In the present study, the input variables for the proposed network were solution pH, contact time, initial adsorbate concentration, adsorbent dose and temperature, whereas the output variable was the percent Pb(II) removal. The network had been trained by using different algorithms and based on the lowest mean squared error (MSE) value and validation error, resilient backpropagation algorithm with 12 neurons in the hidden layer was selected for the present investigation. The tan sigmoid and purelin transfer function were used in the hidden and the output layers of the proposed network, respectively. The model predicted and experimental values of the percent Pb(II) removal were also compared and both the values were found to be in reasonable agreement with each other. The performance of the developed network was further improved by normalizing the experimental data set and it was found that after normalization, the MSE and validation error were reduced significantly. The sensitivity analysis was also performed to determine the most significant input parameter.


Asunto(s)
Carbón Orgánico/química , Monitoreo del Ambiente/métodos , Contaminantes Ambientales/química , Plomo/química , Acacia , Adsorción , Contaminantes Ambientales/análisis , Concentración de Iones de Hidrógeno , Plomo/análisis , Redes Neurales de la Computación , Espectrofotometría Atómica , Temperatura , Factores de Tiempo
8.
J Hazard Mater ; 262: 1176-86, 2013 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-22785008

RESUMEN

Arsenic pollution in groundwater is a worldwide concern due to its chronic effects on human health. Numerous studies have been carried out to obtain cost-effective arsenic removal method. Adsorption using natural materials or its treated forms is found to be cost-effective technology. Raw laterite (RL) or its treated form (TL) is studied recently as arsenic adsorbent for aqueous system. Laterite composition varies with geographical location and extent of lateritization. The study on effects of arsenic adsorption with varying composition of laterite is not explored yet. Four laterite samples with different compositions are examined to remove arsenic from water. These laterite samples are activated using an optimized acid followed by base treatment method in order to determine the effects of RL composition on arsenic adsorption behavior of TL. Higher iron and aluminum containing RL samples show higher arsenic adsorption behavior. Similarly, TL obtained from higher iron and aluminum containing RL sample shows the higher specific surface area (130-180 m(2) g(-1)) and pore volume (0.28-0.35 mL g(-1)). Two household filters using TL are deployed in arsenic affected area of Barasat, 24 Parganas (N), West Bengal, India and their performance is monitored for about a year.


Asunto(s)
Arsénico/análisis , Arsénico/química , Minerales/química , Purificación del Agua/instrumentación , Purificación del Agua/métodos , Absorciometría de Fotón , Adsorción , Aluminio/química , Cationes , Filtración , Agua Subterránea , Concentración de Iones de Hidrógeno , India , Hierro/química , Tamaño de la Partícula , Silicio/química , Espectroscopía Infrarroja por Transformada de Fourier , Temperatura , Agua/química , Contaminantes Químicos del Agua/química , Difracción de Rayos X
9.
Bioresour Technol ; 101(1): 6-13, 2010 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-19717301

RESUMEN

In this study, ricinoleic acid was produced on surfactant enhanced castor oil hydrolysis using Candida rugosa lipase. The most effective surfactant was Span 80. Employing fractional factorial design, the most suitable temperature and surfactant concentration were found to be 31 degrees C and 0.257% (w/w in buffer) respectively whereas pH, enzyme concentration, buffer concentration and agitation were identified as the most significant independent variables. A 2(4) full factorial central composite design was applied and the optimal conditions were found to be pH 7.0, enzyme concentration 7.42 mg/g oil, buffer concentration 0.20 g/g oil and agitation 1400 rpm with the maximum response of 76% in 4 h. The most important variable was pH, whereas enzyme and buffer concentrations also showed pronounced effect on response. This is the first report on the application of response surface methodology for optimizing surfactant enhanced ricinoleic acid production using C. rugosa lipase.


Asunto(s)
Candida/clasificación , Candida/enzimología , Aceite de Ricino/química , Lipasa/química , Ácidos Ricinoleicos/síntesis química , Tensoactivos/química , Técnicas Químicas Combinatorias , Activación Enzimática , Hidrólisis
10.
Bioresour Technol ; 100(18): 4067-73, 2009 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-19419859

RESUMEN

In this study, response surface methodology was applied to optimize process variables like temperature, pH, enzyme concentration (mg/g oil), and buffer concentration (g/g oil) for hydrolysis of castor oil using Candida rugosa lipase. A 2(4) full factorial central composite design was used to develop the quadratic model that was subsequently optimized and the optimal conditions were as follows: temperature 40 degrees C, pH 7.72, enzyme concentration 5.28 mg/g oil, buffer concentration 1g/g oil and there was 65.5% conversion in 6 h. These predicted optimal conditions agreed well with the experimental results. This is the first report on the application of response surface methodology in castor oil hydrolysis using C. rugosa lipase with higher percentage conversion in 6 h.


Asunto(s)
Aceite de Ricino/metabolismo , Ácidos Ricinoleicos/metabolismo , Biocatálisis , Candida/enzimología , Concentración de Iones de Hidrógeno , Lipasa/metabolismo , Temperatura
11.
J Hazard Mater ; 172(2-3): 928-34, 2009 Dec 30.
Artículo en Inglés | MEDLINE | ID: mdl-19717233

RESUMEN

A simple shrinking core model is applied to predict the adsorption kinetics of arsenite and arsenate species onto natural laterite (NL) in a stirred tank adsorber. The proposed model is a two-resistance model, in which two unknown parameters, external mass transfer coefficient (K(f)) and pore diffusion coefficient (D(e)) are estimated by comparing the simulation concentration profile with the experimental data using a nonlinear optimization technique. The model is applied under various operating conditions, e.g., initial arsenic concentration, NL dose, NL particle size, temperature, stirring speed, etc. Estimated values of D(e) and K(f) are found to be in the range of 2.2-2.6 x 10(-11)m(2)/s and 1.0-1.4 x 10(-6)m/s at 305K for different operating conditions, respectively. D(e) and K(f) values are found to be increasing with temperature and stirrer speed, respectively. Calculated values of Biot numbers indicate that both external mass transfer and pore diffusion are important during the adsorption. The model is also applied satisfactorily to predict the arsenic adsorption kinetics of arsenic contaminated groundwater-NL system and can be used to scale up.


Asunto(s)
Arsénico/aislamiento & purificación , Modelos Químicos , Contaminantes Químicos del Agua/aislamiento & purificación , Adsorción , Arseniatos , Arsenitos , Difusión , Cinética , Porosidad
12.
J Phys Chem A ; 111(30): 7066-72, 2007 Aug 02.
Artículo en Inglés | MEDLINE | ID: mdl-17602452

RESUMEN

Electronic absorption and emission spectral characteristics of two ketocyanine dyes have been studied in solution in the presence of alkaline earth metal ions. Absorption spectral studies indicate complex formation between the ions and the dyes in the ground state. Values of the equilibrium constant and the enthalpy change characterizing dye (S0)-metal ion interaction have been determined from the absorption spectral data. In the presence of the metal ions the fluorescence spectrum of the dyes shows two bands pointing to the existence of two emitting species, viz., the solvated and the complexed dye in solution. Time-resolved studies of the dyes in solution containing the metal ions can be explained by a two-state model and indicate the presence of two emitting species in equilibrium. Values of the equilibrium constant for the interaction of metal ion and the dyes in the S1 state have also been estimated.

13.
J Phys Chem A ; 110(29): 9051-6, 2006 Jul 27.
Artículo en Inglés | MEDLINE | ID: mdl-16854015

RESUMEN

Electronic absorption and emission spectral characteristics of a ketocyanine dye have been studied in solution in the presence of lithium perchlorate. Absorption spectral studies indicate complex formation between lithium ion and the dye in the ground state. The value of the equilibrium constant along with the molar absorbance of the absorbing species has been determined for the dye-cation interaction. The energy of maximum fluorescence shifts toward the red with the addition of LiClO(4). Steady-state emission studies point to the existence of two emitting species, viz., the solvated and the complexed dye in equilibrium. The values of the equilibrium constant for the process have been determined in acetone and acetonitrile. Time-resolved studies in the picosecond domain in pure solvents reveal that the lifetime (tau) value increases as the solvation interaction increases. Time-resolved studies also indicate the presence of two emitting species in equilibrium.

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