Tryon's conjecture and Energy and momentum of Bianchi Type Universes

The energy and momentum of the Bianchi type $III$ universes are obtained using different prescriptions for the energy-momentum complexes in the framework of General Relativity. The energy and momentum of the Bianchi $III$ universe is found to be zero for the M\o{}ller prescription. For all other prescriptions the energy and momentum vanish when the metric parameter $h$ vanishes. In an earlier work, Tripathy et al. \cite{SKT15} have obtained the energy and momentum of Bianchi $VI_h$ metric and found that the energy of the Universe vanish only for $h=-1$. This result raised a question: why this specific choice?. We explored the Tryon's conjecture that 'the Universe must have a zero net value for all conserved quantities' to get some ideas on the specific values of this parameter for Bianchi type Universes.Comment: 17 page

Antigenic targets and pathogenicity of anti-aortic endothelial cell antibodies in takayasu arteritis

Anti-endothelial cell antibodies are considered to have an important role in the pathogenesis of Takayasu arteritis (TA). Previously, these antibodies were detected using human umbilical vein endothelial cells, which do not completely represent the antigenicity/functions of aortic endothelial cells, the specific targets in TA. To delineate the precise role of antigenic targets, we investigated such targets as well as the pathogenic mechanism of antibodies directed against aortic endothelial cells (AAECAs) in TA

Ultra fine chromite concentration using spiral concentrator

The conventional chromite beneficiation circuit utilises spiral concentrator for recovering chromite fines and as its efficiency decreases with respect to the decrease in particle size. Pilot scale studies have been performed to understand the effect of different process parameters which influence the separation of ultra fine chromite fines from a typical plant tailing. The process parameters of spiral concentrator such as feed rate (m3/hr), feed pulp density (% solids by weight) and splitter position (cm) are considered for the study. Splitter position has major influence on both grade and recovery of the concentrate fraction of spiral concentrator. Maximum grade of 48.54% Cr2O3 can be achieved in the concentrate fraction of spiral concentrator with 20.41% Cr2O3 recovery. Performance of spiral concentrator at different combination of process parameters was analysed with 3D surface plots

Przezskórna interwencja wieńcowa z dostępu przez tętnicę udową w obrębie nieprawidłowej prawej tętnicy wieńcowej przeprowadzona za pomocą cewnika diagnostycznego 5 F TIG

Anomalous coronary arteries, especially when they are right with a high take-off, are challenging substrates for percuta- neous coronary intervention (PCI). Here, we report the case of a 63 year-old female who had a critical lesion in proximal anomalous right coronary artery having an abnormal take-off, where the ostium failed to get cannulated using multiple guiding catheters. Successful PCI was done using a 5 F TIG diagnostic catheter (Optitorque, Terumo, Japan) through the transfemoral route. The unique shape of the TIG diagnostic catheter allowed coaxial engagement of anomalous right coronary artery, with adequate lesion assessment and stent delivery. Anomalie dotyczące tętnic wieńcowych, zwłaszcza wysokie odejście prawej tętnicy wieńcowej (RCA), wiążą się z trudnościami w trakcie przezskórnej interwencji wieńcowej (PCI). W niniejszym artykule przedstawiono przypadek 63-letniej kobiety, u której stwierdzono krytyczne zwężenie w bliższym odcinku RCA o nieprawidłowym odejściu. U chorej próby kaniulacji ujścia tętnicy kończyły się niepowodzeniem mimo użycia wielu cewników prowadzących. Zabieg PCI udało się skutecznie wykonać za pomocą cewnika diagnostycznego 5 F TIG (Optitorque, Terumo, Japonia) z dostępu przezudowego. Unikatowy kształt cewnika diagnostycznego TIG umożliwił jego współosiowe wprowadzenie do nieprawidłowej RCA i dokonanie odpowiedniej oceny zwężenia oraz umieszczenie stentu

Early outcomes of posterior cruciate retaining primary total knee arthroplasty in patients of osteoarthritis in Indian population

Background: Total knee replacement arthroplasty today has become the final treatment option for patients with unsalvageable, severely arthritic, painful and deformed knees. In India the numbers of such surgeries are steadily on the rise with bulk of the patients being relatively younger group. Amongst several factors affecting the kinematics of knee, variations in surface geometry and the retention or sacrificing the posterior cruciate ligament is considered especially important. The role of the retaining a PCL on the demographic, clinical and functional parameters of a patient undergoing TKA remains controversial. The aim of the study was to evaluate the outcomes of cruciate retaining primary total knee arthroplasty in patients of osteoarthritis in relation to demographic, clinical and functional parameters.Methods: 20 knees from 12 patients of osteoarthritis including 8 females and 4 males in age group 45-80 years were operated with cruciate retaining implants. The pre and postoperative evaluations were done radiologicaly and clinically using new knee society score. Patients were followed up for minimum 1 year.Results: evaluations of patients revealed good postoperative improvements at subsequent follow up in comparison to preoperative scores. The average range of movement improved by 43.3 degree. The objective, patients satisfaction and functional score improved with scores of 89, 34 and 89.7 at 1 year follow up. The walking distance and staircase climbing, squatting scores also did well. Age did not seem to affect overall outcomes with males having slightly better postoperative scoring overall.Conclusions: In Indian population when the patient is young, high demanding, the retention of cruciate ligaments gives excellent postoperative functionality and objectivity and should be always considered as first choice surgery

Influence of shaking table process parameters on concentration of chromite plant tailings

Conventional chromite beneficiation plants of India discards large tonnage of chromite values as plant tailing. In the present investigation, a typical chromite beneficiation plant tailing of Sukinda region has investigated by using wet shaking table for the effective utilisation of the natural resource. In this context, the effect of different process variables such as wash water flow rate, deck tilt angle and feed flow rate has analysed. The interactional effects between different process variables has analysed in terms of 3D response surface plots. It was found that the Cr2O3 content has improved to 61.37% from a feed assaying 24.26%. It was envisaged that deck tilt angle has influence major on both grade and recovery of concentrate fraction of shaking table and in case of interactional effects, the interaction between deck tilt angle and feed flow rate has major influence compared to the others. Second order quadratic equations have developed for the prediction of grade and recovery of concentrate fraction of shaking table

Separation of lepidolite from hard-rock pegmatite ore via dry processing and flotation

ABSTRACT: A mineralogical study of Goncalo lithium-bearing mica-rich pegmatite ore (Portugal) indicated that lepidolite occurs in coarse-grained textures, which allows an appreciable liberation of gangue minerals (quartz, k-feldspar, and albite) from lepidolite. However, the intergrowth of these gangue minerals results in uncomplicated liberation (i.e., inclusions). Taking advantage of this coarse gangue liberation, optical ore sorting through image analysis was attempted in order to predict the grades of different-sized fractions using a random comminution algorithm. The ore-sorting process allowed the production of a marketable Li pre-concentrate product for metallurgy. Moreover, this method also highlighted the possible valuation of the reject as low-Li-content quartz-feldspar mixtures for the ceramic industry (reduction in the temperature of porosity closing). Furthermore, a scaled approach of grinding and sieving allowed the formation of a lepidolite-rich fraction (>210 mu m), which was processed using an electrostatic separator by varying key process parameters. The lepidolite and muscovite were separated to obtain a Li pre-concentrate assaying 3.5 % Li2O from a feed grade containing 1.8 % Li2O. Nevertheless, according to the zeta-potential measurements, the flotation test performed with the finer-sized fraction (-210 + 63 mu m) showed that lepidolite flotation was optimised between pH 3 and 5. In this pH range, concentrates from the rougher stage assayed 4.2-4.5 % Li2O, corresponding to 87-95 % Li recovery. At pH > 5, the selectivity decreases, and SiO2 analysis suggests the flotation of quartz and other silicates rather than lepidolite. Feldspar/quartz flotation was also tested using lepidolite flotation rejects to promote the separation of feldspars from quartz and obtain products for ceramic applications.info:eu-repo/semantics/publishedVersio