Avanish Kumar Srivastava

Lycopene; chemistry, biosynthesis, metabolism and degradation under various abiotic parameters

Lycopene, the predominant carotenoid in tomatoes, is among the major carotenoids in serum and tissues of humans. Epidemiological studies have proven the bioactive role and potential disease prevention property of carotenoids and their consumption has been associated with reduced risk of degenerative diseases. Lycopene is reported to have a variety of pharmacological and nutritional effects in animals and humans, on one hand and promising health benefits as an antioxidant on the other. However, a need exists for better exploration of its biosynthesis, metabolic aspects, tissue distribution and bioavailability. To contribute to this effort, this integrated review presents data on the physico-chemical aspects, biosynthesis and metabolism, with special focus on the stability and degradation under various abiotic parameters. Heat light and oxygen are the main factors which induce degradation of lycopene via trans-cis isomerization and oxidation and reduce its health benefits. The stability of lycopene is also varied in different food matrices. Controversy also exists on some issues such as bioavailability and absorption of this compound which needs to be explored further.

Effect of calcinations temperature of CuO nanoparticle on the kinetics of decontamination and decontamination products of sulphur mustard.

Present study investigates the potential of CuO nanoparticles calcined at different temperature for the decontamination of persistent chemical warfare agent sulphur mustard (HD) at room temperature (30 ± 2 °C). Nanoparticles were synthesized by precipitation method and characterized by using SEM, EDAX, XRD, and Raman Spectroscopy. Synthesized nanoparticles were tested as destructive adsorbents for the degradation of HD. Reactions were monitored by GC-FID technique and the reaction products characterized by GC-MS. It was observed that the rate of degradation of HD decreases with the increase in calcination temperature and there is a change in the percentage of product of HD degradation. GC-MS data indicated that the elimination product increases with increase in calcination temperature whereas the hydrolysis product decreases.

Kinetics of degradation of sulfur mustard and sarin simulants on HKUST-1 metal organic framework

The applicability of HKUST-1 for the degradation of sulfur mustard and sarin simulants was studied with and without coadsorbed water. Degradation was found to be via hydrolysis and dependent on the nucleophilic substitution reaction, vapour pressure and molecular diameter of the toxicants.

Kinetics of adsorption of 2-chloroethylethylsulphide on Al2O3 nanoparticles with and without impregnants.

Alumina nanoparticles in the size range of 2-30 nm and surface area 375 m(2)/g were synthesized using aerogel route and then characterized using N(2)-BET, SEM, TEM, XRD, FTIR and TGA techniques. Thereafter, these were impregnated with reactive chemicals and tested for their potential by conducting studies on kinetics of adsorption of 2-chloroethylethylsulphide (2-CEES) under static conditions. Kinetics was studied using linear driving force and Fickian diffusion model. The kinetics parameters such as equilibration constant, equilibration capacity, diffusional exponent and adsorbate-adsorbent interaction constant were also determined. AP-Al(2)O(3) with 10% impregnation of MoVPA (V(3)) and NaOH showed the maximum (574 mg/g) and minimum (88 mg/g) uptake of 2-CEES among impregnated systems respectively. All impregnated systems except NaOH impregnation showed the values of diffusional exponent to be <0.5, indicated the diffusion mechanism to be Fickian, whereas AP-Al(2)O(3) with and without NaOH impregnation showed the diffusional mechanism to be anomalous. Hydrolysis and dehydrohalogenation reactions (identified using GC/MS technique) were found to be the route of degradation of 2-CEES.

Catalytic removal of carbon monoxide over carbon supported palladium catalyst.

Carbon supported palladium (Pd/C) catalyst was prepared by impregnation of palladium chloride using incipient wetness technique, which was followed by liquid phase reduction with formaldehyde. Thereafter, Pd/C catalyst was characterized using X-ray diffractometery, scanning electron microscopy, atomic absorption spectroscopy, thermo gravimetry, differential scanning calorimetry and surface characterization techniques. Catalytic removal of carbon monoxide (CO) over Pd/C catalyst was studied under dynamic conditions. Pd/C catalyst was found to be continuously converting CO to CO(2) through the catalyzed reaction, i.e., CO+1/2O(2)→CO(2). Pd/C catalyst provided excellent protection against CO. Effects of palladium wt%, CO concentration, humidity, space velocity and reaction environment were also studied on the breakthrough behavior of CO.

Alumina-supported oxime for the degradation of sarin and diethylchlorophosphate

1-(4-Chlorophenyl))-N-hydroxymethanimine and cyclohexyl-N-hydroxymethanimine were synthesized and a well-established oxime, i.e., 2-[(hydroxyimino)methyl]-1-methylpyridinium chloride was purchased. Thereafter; all were loaded over Al(2)O(3) using incipient wetness technique. The prepared systems were characterized using surface area analyzer, scanning electron microscope, energy dispersive X-ray spectrophotometer, Fourier transform infrared spectrophotometer and thermogravimetric analyzer. Kinetics of the degradation of sarin (GB) and simulant, i.e. diethylchlorophosphate (DEClP) was studied over synthesized oxime impregnated Al(2)O(3) and results were compared with well reported oxime impregnated Al(2)O(3). Kinetics of reaction was found to be following the pseudo first order reaction kinetics. The order of reactivity of the prepared systems was found to be cyclohexyl-N-hydroxymethanimine/Al(2)O(3)>1-(4-chlorophenyl)-N-hydroxymethanimine/Al(2)O(3)>2-[(hydroxyimino)methyl]-1-methylpyridinium chloride/Al(2)O(3)>Al(2)O(3). From the reaction kinetics it was observed that the reaction with DEClP was faster than with GB. Cyclohexyl-N-hydroxymethanimine/Al(2)O(3) was found to be the most reactive system with half-life of 0.94 and 15 h for DEClP and GB respectively.

Development and Evaluation of Impregnated Carbon Systems Against Iodine Vapours

In order to understand the breakthrough behaviour of iodine vapours on impregnated carbon systems, an active carbon, 80 CTC grade, BSS particle size and surface area, was impregnated with metal salts such Cu, Cr, Ag, Mo and Zn, and an organic compound Triethylene diamine (TEDA) to prepare different carbon systems such as whetlerite, whetlerite/TEDA, whetlerite/KI/KOH and ASZMT. The prepared adsorbents along with active carbon were characterized for surface area and pore volume by adsorption at liquid nitrogen temperature. These carbon systems were compared for their CT (concentration X time) values at 12.73 to 53.05 cm/sec space velocities and 2 to 5 cm carbon column bed heights. The carbon column of 5.0 cm bed height and 1.0 cm diameter was found to be providing protection against iodine vapours up to 5.5 h at 3.712 mg/L iodine vapour concentration and 12.73 cm/sec space velocity. The study clearly indicated the adsorption capacities of carbon systems to be directly proportional to their surface area values. Dead layer with all the prepared carbon systems was found to be less than 2.0 cm indicating it to be minimum bed height to have protection against vapours. Effect of carbon bed height and flow rate was also studied. The active carbon showed maximum protection at all bed heights and flow rates in comparison to all other impregnated carbon systems, showing that only physical adsorption is responsible for the removal of iodine vapours.

Reconstruction of Stature by Percutaneous Measurement of Foot - An Anthropometric Study

The study ‘Reconstruction of stature by percutaneous measurement of foot’ is a part of our research project ‘Reconstruction of stature from the parts of upper and lower extremities,’ of which regression equations and multiplication factors are derived for the estimation of height from the distal part of upper extremity (combined length of forearm and hand) and from leg. For stature from foot, standing height and length of right and left feet were measured in 100 adult male and female medical students of 19–25 years and analysed statistically to establish relation between height and length of foot them. Regression equations are derived separately for male and female and these are 3.35X+82.6 and 3.42X+75.8, respectively, where X stands for length of foot. By taking the foot length value of different subjects their stature is calculated and compared with the corresponding real standing height and these were close (±3 cm) in most of the cases. Multiplication factor is also calculated, which is 6.49 for male and 6.65 for female. By using these factors the calculated stature is more than ±5 cm in nearly one-third of the cases, suggesting it less reliable than regression equation.

Impregnated Active Carbon-Shelf Life Studies and Its Evaluation Against Cyanogen Chloride with and without Canister

Samples of active carbon of 1150 m2/g surface area were impregnated with ammoniacal salts of copper, chromium and silver, with and without triethylenediamine. The samples of impregnated carbon were aged at 50℃, with and without 90% RH (relative humidity), for a little more than one year and chemically evaluated periodically. Initially copper (II) and chromium (VI) reduced very fast in the samples in humid atmosphere to the extent of 30% and 60% respectively in four months. These values were found to be unaffected by the presence of triethylenediamine (TEDA) indicating that the chemical did not retard the reduction process of chromium (VI) and copper (II). However, in the absence of humidity the reduction of the impregnants was significantly less (10-12%, w/w) in four months. It was quite evident; therefore, that the moisture was mainly responsible for the reduction of chromium (VI) and copper (II) species in impregnated carbons. The prolonged ageing of the samples with and without triethylenediamme after four months with and without humid atmosphere showed that the extent of reduction of chromium (VI) was very low, i.e. 5-10% and of copper (II) was 2-25%. Silver is not reduced due to carbon, as it remained unchanged in concentration on storage. The impregnated carbon samples (100 g) without triethylenediamine, which were aged at room temperature for 5 years in absence of humidity and unaged when evaluated against cyanogen chloride (CNCl) at a concentration of 4 mg/L and airflow rate of 30 lpm showed a high degree of protection (80- 110 minutes).