New cost-effective method for conversion of vegetable oil to biodiesel

A low cost method to convert triglycerides to biodiesel by transesterification reaction has been investigated. The new approach is based on controlled feeding of oil into a pool of alcohol allowing easy dispersion of oil creating large interfacial area for mass transfer. It also enabled equilibrium constants to shift in the forward direction due to excess of alcohol in the dispersion. As a result product yield higher than 95% could be achieved at lower energy input compared to conventional method. Comparisons made with conventional batch and co-solvent enabled method show differences and highlight improvements. Reactions were conducted in one liter reactor at various residence time, temperature and molar ratio of canola oil with methanol in presence of potassium hydroxide as the catalyst. Samples were collected at regular intervals and analyzed by gas chromatography (GC) to determine the reaction progress.

Effect of esomeprazole on pharmacokinetics of phenytoin in rabbits

Esomeprazole is commonly prescribed proton pump inhibitor for gastritis and peptic ulcer disease. Most of the time in clinical practice, phenytoin and esomeprazole are prescribed for patients of generalized seizures with concomitant peptic ulcer. Hence there are chances of drug-drug interaction because of modulations of isoenzymes CYP2C9 and CYP2C19, are involved in metabolism of phenytoin and esomeprazole. But it is important to maintain the therapeutic level of phenytoin in plasma for effective seizures control. So, the aim of the study was to determine the effect of esomeprazole on the pharmacokinetics of phenytoin in rabbits. In a parallel design study, phenytoin, 30 mg/kg/day per oral was given daily for 14 days. On day 15, blood samples were taken at various time intervals between 0-24 hours. In esomeprazole-phenytoin group, phenytoin was administered for seven days as mentioned earlier and from day 8th onward, esomeprazole 2.8 mg/kg along with phenytoin 30 mg/kg/day was administered till 14th days and blood samples were drawn as above on 15th day. Plasma phenytoin levels were assayed by HPLC and pharmacokinetic parameters were calculated. In esomeprazole-phenytoin group, there was a significant increase of t1/2el than phenytoin alone group and significant increase in AUC0-24 was also observed in the esomeprazole and phenytoin treated group. These results suggest that esomeprazole alters the pharmacokinetics of phenytoin. Confirmation of these results in further clinical studies will warrant changes in phenytoin dose or frequency when esomeprazole is co-administered.

Concept development for the ITER equatorial port visible∕infrared wide angle viewing system

The ITER equatorial port visible∕infrared wide angle viewing system concept is developed from the measurement requirements. The proposed solution situates 4 viewing systems in the equatorial ports 3, 9, 12, and 17 with 4 views each (looking at the upper target, the inner divertor, and tangentially left and right). This gives sufficient coverage. The spatial resolution of the divertor system is 2 times higher than the other views. For compensation of vacuum-vessel movements, an optical hinge concept is proposed. Compactness and low neutron streaming is achieved by orienting port plug doglegs horizontally. Calibration methods, risks, and R&D topics are outlined.

Anopheles (Cellia) maculatus group: its spatial distribution and molecular characterization of member species in north-east India

Anopheles (Cellia) maculatus is considered a group of at least nine formally named species. Faced with the difficulty of correct morphological identification due to overlapping characters, several member species of the An. maculatus group are known to play important role in malaria transmission in the Oriental region. Current assemblage, distribution and vectorial importance of the member species within the Maculatus group is far from clear in the north-eastern region of India. Our study encompassing 410 individuals, collected from 67 geo-referenced spots across the eight north-east Indian states, identified the presence of 6 member species of the Maculatus group using the molecular tools. Anopheles dravidicus and Anopheles rampae were documented for the first time in this part of India with latter forming the new country record. While Anopheles pseudowillmori (59.5%) and An. maculatus (32%) were widely available species in most of the north-eastern states, restricted distribution of Anopheles willmori to Nagaland and that of Anopheles sawadwongporni and An. rampae to Mizoram state was noted. None of the species was found positive for human malaria parasite. While no intraspecific differences existed in the sequences of second internal transcribed spacer (ITS2) region of ribosomal DNA (r-DNA) of the member species of the Maculatus group within north-east India, few differences were detected in the sequences of An. dravidicus, An. maculatus and An. pseudowillmori from north-east India with species from the neighbouring countries.

A multiplexed separation of iron oxide nanocrystals using variable magnetic fields

The size-dependent magnetic properties of nanocrystals are exploited in a separation process that distinguishes particles based on their diameter. By varying the magnetic field strength, four populations of magnetic materials were isolated from a mixture. This separation is most effective for nanocrystals with diameters between 4 and 16 nm.

Simultaneous spectrophotometric estimation of norfloxacin and ornidazole in tablet dosage form

Three simple, accurate and economical methods have been developed for the estimation of norfloxacin and ornidazole in tablet dosage form. First method is based on the simultaneous equations, wavelengths selected for analysis were 273.0 nm (λ_max of norfloxacin) and 318.5 nm (λ_max of ornidazole), respectively, in 0.1N NaOH. Second method is Q-analysis method, based on absorbance ratio at two selected wavelengths 297.0 nm (iso-absorptive point) and 318.5 nm (λ_max of ornidazole). Third method is first order derivative spectroscopy using 297.5 nm (zero cross for norfloxacin) and 264.0 nm (zero cross for ornidazole). The linearity was obtained in the concentration range of 4-20 μg/ml and 5-25 μg/ml for norfloxacin and ornidazole, respectively. The results of the analysis have been validated statistically and by recovery studies.

Application of inorganic carrier-based formulations of fluorescent pseudomonads and Piriformospora indica on tomato plants and evaluation of their efficacy

AIMS

Fluorescent pseudomonads are widely used as bioinoculants for improving plant growth and controlling phytopathogenic fungi. Piriformospora indica (Pi), a symbiotic root endophyte, also has beneficial effects on a number of plants. The present study focuses on the improvement of growth yields of tomato plants and control of Fusarium wilt using inorganic carrier-based formulations of two fluorescent pseudomonad strains (R62 and R81) and Pi.

METHODS AND RESULTS

The inorganic carrier-based formulations of pseudomonad strains and Pi were tested for plant growth promotion of tomato plants under glass house and field conditions. In controlled glass house experiments, 8·8-fold increase in dry root weight and 8·6-fold increase in dry shoot weight were observed with talcum powder-based consortium formulation of R81 and Pi. Field trial experiments ascertained the glfass house results with a considerable amount of increase in plant growth responses, and amongst all the treatments, R81 + Pi treatment performed consistently well in field conditions with an increase of 2·6-, 3·1- and 3·9-fold increase in dry root weight, shoot weight and fruit yield, respectively. The fluorescent pseudomonad R81 and Pi also acted as biocontrol agents, as their treatments could control the incidence of wilt disease caused by Fusarium oxysporum f.sp. lycopersici in tomato plants under glass house conditions.

CONCLUSIONS

The culture broths of pseudomonads R62, R81 and Pi were successfully used for development of talcum- and vermiculite-based bioinoculant formulations. In controlled glasshouse experiments, the talcum-based bioinoculant formulations performed significantly better over vermiculite-based formulations. In field experiments the talcum-based consortium formulation of pseudomonad R81 and Pi was most effective.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study suggests that the formulations of pseudomonad strains (R62 and R81) and Pi can be used as bioinoculants for improving the productivity of tomato plants. The application of such formulations is a step forward towards sustainable agriculture.

A comparative study on dissolution rate of sintered (Th-U)O2 pellets in by microwave and conventional heating

ThO2 with approximately 3% 233UO2 is the proposed fuel for the Advanced Heavy Water Reactor (AHWR) and characterized as a mixed oxide (MOX) fuel. Due to the existence of a single oxidation state, quantitative dissolution of MOX samples like (Th-U)O2 and (Th-Pu)O2 is a challenging task for any analytical chemist. However, dissolution is a pre-requisite for complete characterization of the fuel. The present paper describes a detailed study carried out on the comparison of dissolution of sintered (Th-U)O2 mixed oxide pellets, in 16 M HNO3 using microwave and conventional heating techniques, under reflux conditions. The study was carried out with variation of parameters such as concentration of HF and UO2 substitution in the MOX solid solution. The concentration of dissolved U and Th was determined by modified Davies and Gray potentiometric titration and Th-EDTA complexometric titration using xylenol orange as the titration end point indicator respectively. Experimental results clearly indicate that the microwave heating assisted dissolution rate is 2 to 3 times higher than the conventional infrared heating assisted dissolution rate, for sintered pellets. The concentration of HF is a critical parameter, an excess leads to precipitation of insoluble ThF4. The concentration of HF was optimized to 0.025 M. Experimental results also clearly show that at this concentration of HF in 16 M HNO3, a higher substitution of UO2 in MOX solid solution also facilitates the dissolution process. Different trace metal impurities were determined in the MOX samples after dissolving by microwave and infra red heating techniques and it was observed that the results are comparable.

Molecular evidence for the involvement of Anopheles nivipes (Diptera: Culicidae) in the transmission of Plasmodium falciparum in north-eastern India

The Anopheles philippinensis and An. nivipes mosquitoes that form part of the An. annularis species group are morphologically very similar and difficult to differentiate as adults. In consequence, researchers generally refer to all field-collected individuals of these species simply as the An. philippinensis-nivipes species complex. Although this species complex is understood to play a role in the transmission of parasites causing human malaria in north-eastern India, the identity of the exact species involved, and the relative importance of the local An. philippinensis and An. nivipes, are far from clear. To settle this issue, house-frequenting female adults of the An. philippinensis-nivipes species complex were collected from 23 localities in the six north-eastern states, identified to species (using an allele-specific PCR to explore the insects' ribosomal-DNA internal-transcribed-spacer-2 sequences) and checked for Plasmodium DNA (using a nested PCR based on the 18S subunit of the parasite's ribosomal DNA). Of the 337 females of the An. philippinensis-nivipes species complex that were investigated, 275 were identified as An. nivipes and 62 as An. philippinensis. Malarial infection was detected in the heads/thoraces of just two specimens, with P. falciparum DNA detected in one An. nivipes from Nagaland state and one An. nivipes from Assam state. These results provide unambiguous evidence of the presence of both An. philippinensis and An. nivipes in the north-eastern region of India and the involvement of An. nivipes in transmitting P. falciparum in this area.