Radiation and Hall effects on a 3D flow of MHD Williamson fluid over a stretchable surface

Magnetohydrodynamics (MHD) three-dimensional flow of an unsteady Williamson fluid on an enlarging surface with Hall current, radiation, heat source/sink, and chemical reaction is investigated in this article. The basic governing equations are transformed into a system of ordinary differential equations by using an appropriate similarity transformation. The system is deciphered using the shooting method. The properties of influential parameters such as parameters of magnetic field, Hall current, radiation, and so forth, on the flow are discussed with the help of graphs and tables. We noticed that the increase in the magnetic field reduces the velocity in x-direction and the rate of heat and mass transfer. We also acknowledged that the growing values of Hall current parameter boost the velocity in z-direction but it reduce the temperature and concentration distributions, respectively. The results of this study represent many applications in biomedical engineering and these results are helpful for further study of non-Newtonian fluids in various circumstances.     

Dark fermentative biohydrogen production by mesophilic bacterial consortia isolated from riverbed sediments

Dark fermentative bacterial strains were isolated from riverbed sediments and investigated for hydrogen production. A series of batch experiments were conducted to study the effect of pH, substrate concentration and temperature on hydrogen production from a selected bacterial consortium, TERI BH05. Batch experiments for fermentative conversion of sucrose, starch, glucose, fructose, and xylose indicated that TERI BH05 effectively utilized all the five sugars to produce fermentative hydrogen. Glucose was the most preferred carbon source indicating highest hydrogen yields of 22.3 mmol/L. Acetic and butyric acid were the major soluble metabolites detected. Investigation on optimization of pH, temperature, and substrate concentration revealed that TERI BH05 produced maximum hydrogen at 37 °C, pH 6 with 8 g/L of glucose supplementation and maximum yield of hydrogen production observed was 2.0–2.3 mol H₂/mol glucose. Characterization of TERI BH05 revealed the presence of two different bacterial strains showing maximum homology to Clostridium butyricum and Clostridium bifermentans.     

Synthesis of 12-phosphonooleic acid and surfactant properties of its sodium salt

Methyl ricinoleate (9-cis, 12-hydroxyoctadecenoate) was transformed to 12-bromo/iodo-oleate via methyl 12-mesyloxyoleate by homoallylic displacement reaction. The halooleate was reacted with triethyl phosphite to give methyl 12-diethyl phosphonooleate via the Michaelis-Arbuzov reaction under modified conditions. The phosphonooleate was hydrolyzed to 12-phosphonoleic acid using conc. hydrochloric acid. The compounds were characterized by phosphorus estimation and a combination of IR,¹H-NMR and¹³C-NMR spectroscopic techniques. The 12-phosphonooleic acid was neutralized to its sodium salt, and the salt was then studied for its surfactant properties. The sodium phosphonooleate was found to be superior to sodium salts of sulfate and phosphate esters of castor oil, and comparable to sodium lauryl sulfate in wetting ability, emulsifying power and in lowering of surface tension. The sodium phosphonooleate, being a poor foamer, could be used for machine laundry washing, dish washing and cosmetics. IICT Communication No. 2272.     

A process for solid fat from castor oil by simultaneous hydrogénation and dehydration

A single step process has been developed on a pilot plant scale (15 kg/batch) for simultaneous hydrogenation and dehydration of castor oil using nickel catalyst and attapulgite to yield solid fats having a hydroxyl value of 7–33 and an iodine value of 41–56. The polymer and keto fatty acid contents in the products were up to 2% and 3.2%, respectively. The product can be used in the manufacture of soap as the hard fat component and in textile sizing.     

Analysis of Calotropis gigantea,Acacia Caesia and Abelmoschus Ficulneus seeds

The percentage contents of oil and protein in the seeds of Calotropis gigantea Linn. (Asclepiadaceae), Acacia caesia Willd., syn. A. intsia (Leguminosae) and Abelmoschus ficulneus Wight & Arm., syn. Hibiscus ficulneus Linn. (Malvaceae) were 30.8, 8.8 and 14.4, and 19.0, 11.7 and 20.0, respectively. The major fatty acid was 18:1 in C. gigantea and 18:2 in the other two seeds oils. Malvalic, sterculic and dihydrosterculic acids were present in small quantities in A. ficulneus seed oil. The major essential amino acids in the seed proteins were phenylalanine, lysine and histidine in C. gigantea, threonine and arginine in A. caesia and lysine and phenylalanine in A. ficulneus.     

Characteristics and composition of six malvaceae seeds and the oils

The seeds ofSida veronicifolia Linn., syn.S. bumilis cav.,S. cordifolia Linn.,S. ovata Forsk.,S. mysorensis W & A., syn.S. urticaefolia W & A,S. rhombifolia var.retusa Masters andAbutilon crispum Medik. (Malvaceae) contained 15.5%, 11.5%, 12.1%, 13.2%, 20.2% and 12.5% oil, and 15.0%, 14.1%, 17.3%, 13.6%, 12.6% and 18.4% protein, respectively. Linoleic acid predominated (54.9–69.4%) as the fatty acid of all the oils, and malvalic (1.3–11.4%) and sterculic acids (0.4–1.1%) were significant.     

Applicability of the turbidity test for castor oil to some other hydroxy and epoxy fatty compounds

A large number of hydroxy as well as nonhydroxy fatty compounds were employed to explore the applicability of the turbidity test for castor oil (1) and to understand the nature of the turbidity. The test was capable of detecting up to ca. 2% of hydroxy, hydroperoxy, and epoxy fatty acids and their esters, also the epoxy, acetoxy, and hydroxy fatty alcohols present in a petroleum ether solution of a nonpolar triglyceride oil. Monohydric primary alcohols, sterols, mono- and diglycerides were not detected. The turbidity developed, whether H₂SO₄ contained ammonium molybdate or not, because of the formation of a sulfate and its precipitation from the petroleum ether solution of oil.     

High pressure splitting of castor oil

The effects of variations in pressure (20–40 kg/cm²), oil-to-water ratio (1:0.4–1:1, w/w) and time (0–8 hr) on the extent of hydrolysis of castor oil were studied. Higher pressure, lower oil-to-water ratio and longer duration gave higher percentage splits. At 40 kg/cm² pressure and an oil-to-water ratio of 1:1, ca. 92% split was obtained in 8 hr. When the oil was hydrolyzed in 2 stages at 20 kg/cm² with an oil-to-water ratio of 1:0.4, ca. 96% split was obtained in a total period of 10 hr. Splitting at 20 kg/cm² gave minimal amounts of dienoic acids because of the decomposition of estolides.     

On a finite element model for the analysis of through cracks in laminated anisotropic cylindrical shells

A finite element model for the analysis of laminated composite cylindrical shells with through cracks is presented. The analysis takes into account anisotropic elastic behaviour, bending-extensional coupling and transverse shear deformation effects. The proposed finite element model is based on the approach of dividing a cracked configuration into triangular shaped singular elements around the crack tip with adjoining quadrilateral shaped regular elements. The parabolic isoparametric cylindrical shell elements (both singular and regular) used in this model employ independent displacement and rotation interpolation in the shell middle surface. The numerical comparisons show the evidence to the conclusion that the proposed model will yield accurate stress intensity factors from a relatively coarse mesh. Through the analysis of a pressurised fibre composite cylindrical shell with an axial crack, the effect of material orthotropy on the crack tip stress intensity factors is shown to be quite significant.     

Changes in polyphenols of sapota fruit (Achras zapota L.) during maturation

The changes in polyphenols of sapota fruit during maturation have been determined by chemical analysis, paper chromatography and taste evaluation. Simple polyphenols are shown to decrease while polymeric leucoanthocyanidins increase with maturation. The reduction in astringency as the fruit develops has been found to be due to polymeric changes, the influence of other constituents such as sugar, and ‘dilution’ of polyphenols by increase in fruit size.