Developments in Phosphate-rock beneficiation and the problems with Indian phosphorites

Phosphate-rock or more precisely the phosphorites form the repository of phosphate supply for the fertilizer industry for manufacture of elemental phosphorus, phospho- ric acid and innumerable alkali phosphates. It has been universally agreed that phosphorites have some kind of sedimentary marine origin, the source of phosphorous being of organic and/or inorganic origin(1). The principal phos-phate mineral occuring in these deposits is referred by its generic designation as collophane (2), a carbonate bearing variety apatite, whose formula is approximately Cato ( PO4 CO3.H20 with a little of F. It is porous and crypto-crystalline, occuring as compact nodules or pellets as disseminations in calcitic or qurtzitic sedimentary rocks along with clay, sericite, silt, chert, free carbon and invariably associated with a little uranium (0.002 to 0.008% U308 e). The typical apatite [Ca 6(PO4)3 F] is cry-stalline and occurs usually in igneous and metamorphic rocks, pegmatites, granites, and schists. Its chemical composition is more defined and constant compared to the collophane of sedimentary origin. Fertilizer industry, though uses phosphate from both sources; the super phos-phate manufacturers prefer phosphate-concentrates from phosphorite because of the ease with which collophane goes into solution with sulphuric acid. The physical charac-teristics of collophane also have bearing on its flota-bility

Implementation of phase imbalance scheme for stabilizing torsional oscillations

This paper implements the phase imbalance scheme for damping torsional oscillations of a series capacitor compensated power system. The IEEE Second Benchmark Model, system-1, wherein two turbine generator model and two system model connected to an infinite bus is employed as a standard system model to study the concept of subsynchronous resonance. The turbine generator models have a common torsional mode. The Electromagnetic Transients Program (EMTP) is employed to simulate the damping effects provided by the phase imbalance scheme. The simulation results also show that parallel phase imbalance scheme gives the better damping characteristics when compared to that of series phase imbalance scheme.DOI:http://dx.doi.org/10.11591/ijece.v4i5.629

Efficient expression of transgenes in adult zebrafish by electroporation

BACKGROUND: Expression of transgenes in muscle by injection of naked DNA is widely practiced. Application of electrical pulses at the site of injection was demonstrated to improve transgene expression in muscle tissue. Zebrafish is a precious model to investigate developmental biology in vertebrates. In this study we investigated the effect of electroporation on expression of transgenes in 3–6 month old adult zebrafish. RESULTS: Electroporation parameters such as number of pulses, voltage and amount of plasmid DNA were optimized and it was found that 6 pulses of 40 V·cm(-1 )at 15 μg of plasmid DNA per fish increased the luciferase expression 10-fold compared to controls. Similar enhancement in transgene expression was also observed in Indian carp (Labeo rohita). To establish the utility of adult zebrafish as a system for transient transfections, the strength of the promoters was compared in A2 cells and adult zebrafish after electroporation. The relative strengths of the promoters were found to be similar in cell lines and in adult zebrafish. GFP fluorescence in tissues after electroporation was also studied by fluorescence microscopy. CONCLUSION: Electroporation after DNA injection enhances gene expression 10-fold in adult zebrafish. Electroporation parameters for optimum transfection of adult zebrafish with tweezer type electrode were presented. Enhanced reporter gene expression upon electroporation allowed comparison of strengths of the promoters in vivo in zebrafish

A Concise, Phosphate-Mediated Approach to the Total Synthesis of (−)-Tetrahydrolipstatin

An efficient synthesis of (−)-tetrahydrolipstatin (THL) is reported. This method takes advantage of a phosphate tether-mediated, one-pot, sequential RCM/CM/hydrogenation protocol to deliver THL in 8 total steps from a readily prepared (S,S)-triene. The strategy incorporates selective cross metathesis, regio-selective hydrogenation, regio- and diastereoselective cuprate addition and Mitsunobu inversion for installation of the C5 formamide ester subunit

A Phosphate Tether-Mediated, One-pot, Sequential RCM/CM/Chemo-selective Hydrogenation Protocol

A versatile three-step, one-pot, sequential reaction protocol involving RCM, CM, and chemoselective hydrogenation is reported. This phosphate tether-mediated process occurs without intermediate isolation, is chemoselective and is governed by stereoelectronic properties innate to phosphate tethers, which ultimately act to preserve the integrity of the bisallylic, bicyclic phosphate for subsequent nucleophilic additions. Overall, this process can be used to efficiently generate advanced polyol synthons

ANDROID & ARDUINO BASED SMART HOME AUTOMATION

The project aims at designing smart home automation system controlled through Android phone over Bluetooth technology. The electrical loads can be controlled remotely using android application in android phone

Comparative evaluation of fracture resistance of self adapting PFS and elastic FRC post and core systems – An invitro study

Background:  Endodontically treated teeth (ETT) with extensive coronal destruction are more prone to fracture, so restoring these teeth with techniques that will not compromise the integrity of remaining tooth structure with the use of Post and core systems to retain full and final crown restorations seems mandatory. Anatomic posts have been introduced which have better adaptability to the canal anatomy and conserve more amount of tooth structure. Aim: This study was done to compare the fracture resistance of ETT restored with two anatomic post systems elastic FRC post (everStick) and self adapting PFS (Spirapost). Materials and Methods: Twenty single rooted maxillary central incisors were selected for the study. All the samples were endodontically treated and randomly divided into 2 groups (n=10) according to the post system used (PFS post – Group I, FRC– Group II). In all the samples, post space preparation was done and the posts were luted using dual cure resin cement (Para core, Coltene, Mumbai, India).The remaining core was built using composite resin (Filtek, 3M, ESPE, USA). The samples were stored in saline for one week. All the samples were thermocycled for 500 cycles from 5 to 55 0 c ±5 0 c with a dwelling time of 30 seconds in each bath and a transfer time of five seconds. Fracture resistance of the samples was measured using universal testing machine. The obtained data was statistically analyzed by using independent t test. Results: There was no statistically siginificant difference between fracture resistance values of FRC and PFS groups. 30% and 70% of the samples of PFS and FRC showed favourable fractures respectively. Conclusion: In this study it was concluded that fracture resistance of PFS was comparable to that of FRC post. However FRC group showed predominantly more number of favourable fractures. &nbsp

A Reverse Phase HPLC Method Development and Validation for the Determination of Paliperidone in Pure and Dosage Forms

Abstract: A simple reverse phase HPLC method was developed and validated for the assay of paliperidone in pure and tablets. The analysis was carried out on Shimadzu HPLC model equipped with inertsil ODS C-18 column, LC-10AT pump, variable wavelength programmable UV-Detector SPD-10AVP and rheodyne injector with 20µL fixed loop. Acetonitrile and methanol in the ratio 10:90 v/v at a flow rate of 1.0 mL/min was employed for elution and the components were detected at 235 nm at ambient temperature. The method was validated as per the ICH guidelines. The retention time for paliperidone was found to be 5.67 min. Linearity was observed in the concentration range of 20-120 ppm with correlation coefficient 0.9990. The percent of relative standard deviation of six replicate measurements was found to be 1.25 indicate that the proposed method was precise. Recovery studies were conducted at three different concentration levels within the linearity limits and the average percent of recovery was 99.56. The amount of paliperidone drug content present in tablet dosage form was determined and found to be 99.80%. Therefore, the developed method was simple, precise and accurate and can be successfully applied for the estimation of paliperidone in pharmaceutical dosage form