Influence of gas injection on viscous and viscoelastic properties of Xanthan gum

Xanthan gum is widely used as a model fluid for sludge to mimic the rheological behaviour under various conditions including impact of gas injection in sludge. However, there is no study to show the influence of gas injection on rheological properties of xanthan gum specifically at the concentrations at which it is used as a model fluid for sludge with solids concentration above 2%. In this paper, the rheological properties of aqueous xanthan gum solutions at different concentrations were measured over a range of gas injection flow rates. The effect of gas injection on both the flow and viscoelastic behaviour of Xanthan gum (using two different methods - a creep test and a time sweep test) was evaluated. The viscosity curve of different solid concentrations of digested sludge and waste activated sludge were compared with different solid concentrations of Xanthan gum and the results showed that Xanthan gum can mimic the flow behaviour of sludge in flow regime. The results in linear viscoelastic regime showed that increasing gas flow rate increases storage modulus (G'), indicating an increase in the intermolecular associations within the material structure leading to an increase in material strength and solid behaviour. Similarly, in creep test an increase in the gas flow rate decreased strain%, signifying that the material has become more resistant to flow. Both observed behaviour is opposite to what occurs in sludge under similar conditions. The results of both the creep test and the time sweep test indicated that choosing Xanthan gum aqueous solution as a transparent model fluid for sludge in viscoelastic regime under similar conditions involving gas injection in a concentration range studied is not feasible. However Xanthan gum can be used as a model material for sludge in flow regime; because it shows a similar behaviour to sludge

Genetic Diversity and Population Structure of <i>Theileria annulata</i> in Oman

Background: Theileriosis, caused by a number of species within the genus Theileria, is a common disease of livestock in Oman. It is a major constraint to the development of the livestock industry due to a high rate of morbidity and mortality in both cattle and sheep. Since little is currently known about the genetic diversity of the parasites causing theileriosis in Oman, the present study was designed to address this issue with specific regard to T. annulata in cattle. Methods Blood samples were collected from cattle from four geographically distinct regions in Oman for genetic analysis of the Theileria annulata population. Ten genetic markers (micro- and mini-satellites) representing all four chromosomes of T. annulata were applied to these samples using a combination of PCR amplification and fragment analysis. The resultant genetic data was analysed to provide a first insight into the structure of the T. annulata population in Oman. Results: We applied ten micro- and mini-satellite markers to a total of 310 samples obtained from different regions (174 [56%] from Dhofar, 68 [22%] from Dhira, 44 [14.5%] from Batinah and 24 [8%] from Sharqia). A high degree of allelic diversity was observed among the four parasite populations. Expected heterozygosity for each site ranged from 0.816 to 0.854. A high multiplicity of infection was observed in individual hosts, with an average of 3.3 to 3.4 alleles per locus, in samples derived from Batinah, Dhofar and Sharqia regions. In samples from Dhira region, an average of 2.9 alleles per locus was observed. Mild but statistically significant linkage disequilibrium between pairs of markers was observed in populations from three of the four regions. In contrast, when the analysis was performed at farm level, no significant linkage disequilibrium was observed. Finally, no significant genetic differentiation was seen between the four populations, with most pair-wise FST values being less than 0.03. Slightly higher FST values (GST’ = 0.075, θ = 0.07) were detected when the data for T. annulata parasites in Oman was compared with that previously generated for Turkey and Tunisia. Conclusion: Genetic analyses of T. annulata samples representing four geographical regions in Oman revealed a high level of genetic diversity in the parasite population. There was little evidence of genetic differentiation between parasites from different regions, and a high level of genetic diversity was maintained within each sub-population. These findings are consistent with a high parasite transmission rate and frequent movement of animals between different regions in Oman

Soil information system: use and potentials in humid and semi-arid tropics

The articles presented in this special section emanated from the researches of consortium members of the National Agricultural Innovative Project (NAIP, Component 4) of the Indian Council of Agricultural Research (ICAR), New Delhi. These researches have helped develop a soil information system (SIS). In view of the changing scenario all over the world, the need of the hour is to get assistance from a host of researchers specialized in soils, crops, geology, geography and information technology to make proper use of the datasets. Equipped with the essential knowledge of data storage and retrieval for management recommendations, these experts should be able to address the issues of land degradation, biodiversity, food security, climate change and ultimately arrive at an appropriate agricultural land-use planning. Moreover, as the natural resource information is an essential prerequisite for monitoring and predicting global environmental change with special reference to climate and land use options, the SIS needs to be a dynamic exercise to accommodate temporal datasets, so that subsequently it should result in the evolution of the soil information technology. The database developed through this NAIP would serve as an example of the usefulness of the Consortium and the research initiative of ICAR involving experts from different fields to find out the potentials of the soils of humid and semi-arid bioclimatic systems of the country

Georeferenced soil information system: assessment of database

Land-use planning is a decision-making process that facilitates the allocation of land to different uses that provide optimal and sustainable benefit. As land-use is shaped by society–nature interaction, in land-use planning different components/facets play a significant role involving soil, water, climate, animal (ruminant/ non-ruminant) and others, including forestry and the environment needed for survival of mankind. At times these components are moderated by human interference. Thus land-use planning being a dynamic phenomenon is not guided by a single factor, but by a complex system working simultaneously,which largely affects the sustainability. To address such issues a National Agricultural Innovation Project (NAIP) on ‘Georeferenced soil information system for land-use planning and monitoring soil and land quality for agriculture’ was undertaken to develop threshold values of land quality parameters for land-use planning through quantitative land evaluation and crop modelling for dominant cropping systems in major agro-ecological sub-regions (AESRs) representing rice–wheat cropping system in the Indo-Gangetic Plains (IGP) and deep-rooted crops in the black soil regions (BSR). To assess the impact of landuse change, threshold land quality indicator values are used. A modified AESR map for agricultural landuse planning is generated for effective land-use planning

Total hip arthroplasty for hip arthritis with protrusio acetabuli using autograft reconstruction and metal wire mesh

A 70-year-old female patient presented with left hip arthritis following longstanding painfully restricted hip movement for 2 years. X-rays showed protrusio acetabuli with avascular necrosis of head femur. The patient was operated for hip arthritis; hybrid total hip replacement was done with reconstruction of the medial wall with autologous bone graft of femoral head using stainless steel metal wire mesh on which cemented acetabular component with non-cemented femoral component was fixed. Cages and wire mesh are used to reconstruct the medial wall of acetabulum, but cage is a costlier option than wire mesh, with reproducible results. Very few cases have been reported, showing excellent results with the use of metal wire mesh

DEVELOPMENT AND VALIDATION OF STABILITY INDICATING RP-HPLC FOR DETERMINATION OF ATORVASTATIN CALCIUM and EZETIMIBE IN BULK AND PHARMACEUTICAL DOSAGE FORMS

Objective: A simple, speciï¬c, sensitive, accurate and precise stability indicating methods were described for the quantitative determination of the lipid-lowering agent drug Atorvastatin calcium and Ezetimibe.Methods: The method was high performance liquid chromatographic with the use of a reversed phase Grace C-18 column (250 mm x 4.66 mm, i.d. 5 µm) and a mobile phase of buffer: acetonitrile (60:40 v/v) at a flow rate of 1.0 ml/min.Results: The retention time of drug was found to be 6.91 min. and 10.31 min, respectively. Quantiï¬cation of the drug was achieved with UV detection at 240 nm. Linear calibration curve was obtained in concentration range 2–12 µg/ml for both drugs, with r2value of 0.9992 and 0.9990. The limit of detection and limit of quantiï¬cation were found to be 0.81 µg/ml and 2.47 µg/ml respectively for Atorvastatin calcium and 0.76 µg/ml and 2.31 µg/ml respectively for Ezetimibe.Conclusion: The developed methods were successfully validated as per International Conference on Harmonization guideline (ICH). Atorvastatin calcium and Ezetimibe was subjected to different stress conditions. Stress samples were successfully assayed by developed high performance liquid chromatographic and high-performance thin layer liquid chromatographic method. Statistically, analysis proves that there were no statistically signiï¬cant differences between two developed methods.Keywords: RP-HPLC, Atorvastatin calcium, Ezetimibe, Stability indicating, Validatio

Investigation of the conductivity of Na2SO4–PbTiO3 composite electrolyte system: Non linear electrical behavior at Curie temperature of the dispersoid

The effect of dielectric constant of the PbTiO3 dispersoid on the conductivity of Na2SO4 has been probed. At the Curie temperature, 490 °C, PbTiO3 undergoes ferroelectric to paraelectric phase transition followed by a sharp change in the dielectric constant. The Na2SO4–PbTiO3 composites have been prepared at two different temperatures, namely 600 and 900 °C. Compositions containing 5, 10, 20, 30, 40, 50 m% PbTiO3 have been investigated using Impedance Spectroscopy, Differential Scanning Calorimetry (DSC), X-ray diffraction (XRD) and Rietveld analysis. The series of compositions prepared at 900 °C exhibit a maxima in the conductivity for 20 m% PbTiO3. The composites prepared at 600 °C exhibit a peak in the conductivity at 20 m% PbTiO3 in addition to the percolation threshold at 40 m% PbTiO3. The enhancement in the conductivity by a factor of 40 at 300 °C has been observed for the system prepared at 600 °C while an enhancement in the conductivity by a factor of 8 at 300 °C has been observed for the system prepared at 900 °C. Further, the transition temperature of Na2SO4 remains unaltered for both series. A slight nonlinearity has been observed in the vicinity of the transition temperature of the dispersoid© Elsevie