Numerical simulation of three-phase flow in an external gear pump using immersed boundary approach

This paper presents a three-phase fully compressible model applied along with an immersed boundary model for predicting cavitation occurring in a two dimensional gear pump in the presence of non-condensable gas (NCG). Combination of these models is capable of overcoming numerical challenges such as modelling the contact between the gears and simulating the effect of NCG in cavitation. The model accounting for the effect of NCG also has broader applicability, since gas dissolved in liquids can come out of the solution when exposed to low pressures; this plays a significant role in the pump performance and cavitation erosion. Here the simulation results are presented for the gear pump at different operating conditions including the contact between gear, gear RPM and % of NCG; their effects on performance and cavitation is demonstrated. The results suggest that modelling the contact between the gears play a role in the cavitation prediction inside the gear pump. An increase in cavitation is observed when the contact is modelled even for the small pressure difference considered between the inlet and outlet. An increase in the RPM of the gears also results in increased cavitation within the pump, whereas an increase in the percentage of NCG content by a small amount can reduce the cavitation to a greater extent. This reduction is due to the expansion of the gas at a lower pressure which recovers the pressure and prevents or delays the phase-change process of the working fluid. The fluctuations in the outflow rate is also found to increase when the gears are in contact and also with increasing gas content

Edible oysters — Present status of product development and domestic market potential in India

The fishery for oyster is worldwide. Extensive scientific studies on this species have taken place in our country also and the fishery, though in a moderate scale, is in existence along the coasts of Maharashtra and Kerala

Association of maternal plasma or serum zinc concentration with the birth weight of the child

Background: Zinc is a divalent cation first isolated in 1509 and since then its importance has been increasingly recognised in human health and nutrition. Present study has been undertaken to confirm the association between maternal plasma or serum zinc concentration and birth weight.Methods: Present study was cross-sectional study conducted in tertiary care hospital. Newborns with a birth weight of < 2.5kg and their mothers labelled as study group while newborns with a birth weight of > 2.5kg and their mothers were considered as control group. The analysis for the serum concentration of zinc was done using the Atomic Absorption Spectrophotometric method (AAS), this method analytically the most reliable for routine assessment of serum zinc levels. The results deduced from the analysis were accordingly grouped to the study group / control group. We had a sub-group analysis based on the gestational age, as Preterm and Term.Results: Maternal serum levels of zinc 67.04 μg /dl±16.66, in the study group, was less as compared to the maternal serum levels of zinc in the control group with a mean level of 75.39 μg/dl±17.89. The results show a significant association between zinc levels and birth weight. Mean Maternal serum levels of zinc 67.04 μg /dl±16.66, in the study group, was less as compared to the maternal serum levels of zinc in the control group with a mean level of 75.39 μg/dl±17.89. The results show a significant association between zinc levels and birth weight.Conclusions: Present study showed a positive correlation of maternal zinc levels with birth weight and prematurity. Hence, we recommend routine zinc supplementation could be included with other nutritional supplements during pregnancy

EFFECT OF MOMORDICA CHARANTIA AND SYZYGIUM CUMINI EXTRACT ON SERUM ELECTROLYTES IN ALLOXAN INDUCED DIABETIC RATS

Objective: Diabetes is a group of disorders characterized by high blood glucose levels. Disturbances in serum electrolytes like sodium (Na+) and potassium (K+) are found in diabetes. The purpose of the study was to investigate the disturbances in concentrations of serum electrolytes in hyperglycemic crisis and the effect of syzygium cumini and momordica charantia standardized aqueous extracts on serum electrolytes (Na+and K+) in normal and diabetic rats.Methods: Diabetes is induced by intraperitoneal injection of alloxan at a dose of 120 mg/kg b. w in rats. Rats were divided into 5 groups (normal control, disease control, metformin, test 1 and test 2). In test groups 1 and 2, SASESC (standardized aqueous seed extract of syzygium cumini) and SAFEMC (standardized aqueous fruit extract of momordica charantia) were respectively administered orally to alloxan induced diabetic rats, and their serum electrolyte levels were observed at 1st, 4th, 7th and 14th days.Results: By the 14thday, the Na+ and K+ levels in groups 4 and 5 were almost normal. However, in group 3 (standard), Na+levels were relatively lower and K+ levels were relatively higher than groups 4 and 5 (test). In group 2 (disease control) as compared to group 1 (normal control), a decrease in Na+ and increase in K+ levels was observed even on day 14.Conclusion: Treatment with anti diabetic drugs like metformin, syzygium cumini (test-1), momordica charantia (test-2) restored the electrolyte levels almost back to normal over a period of study (14 d). There was significant (**P<0.01, *P<0.05) normalization of electrolyte levels in diabetic rats. It was concluded that syzygium cumini and momordica charantia showed better efficiency in restoring the electrolyte imbalance as compared to metformin during our study

Kinetics of Oxidation of Heterocyclic Compounds by Quinolinium Dichromate

Quinolinium dichromate in sulfuric acid oxidized heterocyclic aldehydes (to the corresponding acids) and heterocyclic carboxylic acids (to the corresponding hydroxy-substituted acids) in acetic acidwater medium (vol. ratio, v(water)/v(acetic acid) = 50:50). The kinetic results supported a mechanistic pathway proceeding via a rate-determining decomposition of the chromate ester

Quinolinium Dichromate Oxidation of Aliphatic Aldehydes: A Kinetic Study

Kinetic data on the rates of quinolinium dichromate oxidation of a series of aliphatic aldehydes have been determined and discussed with reference to aldehyde hydration equilibria. Kinetic results support a pathway proceeding via a rate-determining oxidative decomposition of a chromate ester of an aldehyde hydrate. A cyclic transition state is suggested; being a Hückel-type system (4n + 2), this would be an allowed process. The deuterium isotope effect for the oxidation of acetaldehyde (kH / kD = 6.4) indicated a carbon-hydrogen cleavage rather than a carbon-carbon cleavage

Kinetics of Oxidation of Heterocyclic Compounds by Quinolinium Dichromate

Quinolinium dichromate in sulfuric acid oxidized heterocyclic aldehydes (to the corresponding acids) and heterocyclic carboxylic acids (to the corresponding hydroxy-substituted acids) in acetic acidwater medium (vol. ratio, v(water)/v(acetic acid) = 50:50). The kinetic results supported a mechanistic pathway proceeding via a rate-determining decomposition of the chromate ester

Microbial insight into rhizosphere of arecanut palms of Wayanad using metagenomics

The rhizosphere bacterial diversity of a plant is considered to play an essential role in mediating plant as well as soil health. An attempt to explore the bacterial diversity in the rhizosphere of arecanut palms in Wayanad was done to obtain an understanding of dominant bacterial phylotypes and the status of nutrient concentrations in rhizosphere soil and plants. Since arecanut production in Wayanad is facing a decline, a study to understand the rhizosphere conditions of healthy palms essentially provided insight into what strategies needed to be adopted for improvement of arecanut cultivation. The nutrient imbalance involving increased iron in soil and deficiencies of calcium, magnesium, zinc, and boron in the Arecanut rhizosphere was found to be an evident reason for the decline in production. Apart from that, the biological activities in the rhizosphere by the diversity of microorganisms were studied to understand the dominant bacterial phyla and genera present in the Arecanut rhizosphere. The presence of various important bacterial phyla like Proteobacteria, Actinobacteria, Acidobacteria, Firmicutes, and Bacteroidetes revealed the presence of various beneficial soil microorganisms and emphasized the need to enhance or augment the population of native microflora for efficient nutrient cycling by increasing the organic content of the soil. Since organic carbon is an essential requirement to support bacterial diversity, proper management practice that encompasses organic carbon amendment along with proper nutritional management could enhance bacterial diversity as well as health of the arecanut palms. The study indicated that the dominant bacterial phyla contained various beneficial microorganisms that can be exploited for improving nutrient recycling in the arecanut rhizosphere

SYNTHESIS, CHARACTERISATION AND APPLICATION OF PHENOL-FORMALDEHYDE RESIN BLENDED WITH SULPHONATED PHYLLANTHUS EMBLICA, LINN., CARBON

Phenol – Formaldehyde Resin (PFR) is blended with Sulphonated Phyllanthus emblica, Linn., Carbon (SPEC) in various proportions by weight percentage (0-50%w/w). A few composite cation-exchangers were prepared by varying the amount of SPEC (a source of cheap and renevable plant material) in the blends from 10 to 50% (w/w). Reaction conditions for the preparation of blends were optimised. IR spectra, TGA traces, and SEM photos were taken for the characterization of  resins. Physico-chemical, properties of the composite resins have been determined. The composites are insoluble in various solvents and reagents and stable towards heat.   Cation exchange capacity (CEC) of the composite resins, decreased with the increasing percentage of SPEC in the blend. Thermodynamic equilibrium constants (lnK) are calculated for H+ - Zn2+ exchanges on the resins having a different amount of SPEC. Thermodynamic parameters are also calculated and suitable explanations are given. The composites up to 20% (w/w) blending retains all the essential properties of the original PFR, since the Phyllanthus emblica, Linn., is the low cost, freely available plant material. Therefore, the composites could be used as low cost ion-exchangers, when SPEC partly replaces the original PFR up to 20% (w/w) blending without affecting the properties of PFR