Pseudo-half-metalicity in the double perovskite Sr2_2CrReO6_6 from density-functional calculations

The electronic structure of the spintronic material Sr$_2$CrReO$_6$ is studied by means of full-potential linear muffin-tin orbital method. Scalar relativistic calculations predict Sr$_2$CrReO$_6$ to be half-metallic with a magnetic moment of 1 $\mu_B$. When spin-orbit coupling is included, the half-metallic gap closes into a pseudo-gap, and an unquenched rhenium orbital moment appears, resulting in a significant increase of the total magnetic moment to 1.28 $\mu_B$. This moment is significantly larger than the experimental moment of 0.9 $\mu_B$. A possible explanation of this discrepancy is that the anti-site disorder in Sr$_2$CrReO$_6$ is significantly larger than hitherto assumed.Comment: 3 Pages, 1 figure, 1 Tabl

Phase Stability and Thermoelectric Properties of the Mineral FeS2: An Ab Initio Study

First principles calculations were carried out to study the phase stability and thermoelectric properties of the naturally occurring marcasite phase of FeS$_2$ at ambient condition as well as under pressure. Two distinct density functional approaches has been used to investigate the above mentioned properties. The plane wave pseudopotential approach was used to study the phase stability and structural, elastic, and vibrational properties. The full potential linear augment plane wave method has been used to study the electronic structure and thermoelectric properties. From the total energy calculations, it is clearly seen that marcasite FeS$_2$ is stable at ambient conditions, and it undergoes a first order phase transition to pyrite FeS$_2$ at around 3.7 GPa with a volume collapse of about 3$\%$. The calculated ground state properties such as lattice parameters, bond lengths and bulk modulus of marcasite FeS$_2$ agree quite well with the experiment. Apart from the above studies, phonon dispersion curves unambiguously indicate that marcasite phase is stable under ambient conditions. Further, we do not observe any phonon softening across the marcasite to pyrite transition and the possible reason driving the transition is also analyzed in the present study, which has not been attempted earlier. In addition, we have also calculated the electronic structure and thermoelectric properties of the both marcasite and pyrite FeS$_2$. We find a high thermopower for both the phases, especially with p-type doping, which enables us to predict that FeS$_2$ might find promising applications as good thermoelectric materials.Comment: 10 Figure

An Enhanced VCS of Image Encryption using SDS algorithm without secret keys

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Use and Phytochemical Activity of Celosia Argentea Linn

Since ancient time in India. Celosia argentea linn. Is widely used in traditional medicine, to cure several disorders such as fever, diarrhea, mouth sores, itching wound, jaundice, gonorrhea and inflammation. Literaterature survey from books and journal of traditional Indian medicine revealed that celosia argentia linn. has a lot of medicinal properties. Leaves, stem and root have been reported for medicinal activity, the plant has pharmacologically been studied for various cativities like anti-cancer, hepatoprotection, anti-dibetes etc. However too many scientific studies have been carried out on this plant. For exploring these traditional uses. The present report is deals with traditional uses and pharmacological activity of celosia argentea linn. In the treatment of various diseases

Steroid cell tumour of the ovary: a case report with review of literature

Virilising ovarian tumours account for less than 5% of all ovarian tumours. A steroid cell tumour (SCTs) of the ovary comes under the sex cord stromal tumours and accounts for only 0.1% of all ovarian tumours. Almost 75% are functioning tumors with production of androgenic hormones causing virilisation and cushingoid features. They are usually unilateral, benign with only 25-45% malignant cases. Here authors report the incidence of steroid cell tumour in our institution and discuss about a 37-year-old woman with steroid cell tumour, not otherwise specified who presented with oligomenorrhea followed by amenorrhea, secondary infertility and signs of virilisation

Large chorangiomas: a seven years study in a tertiary care obstetrics and gynaecology hospital

Background: Chorangioma is a benign vascular placental tumour. It is composed of fetal capillary proliferation within the chorionic villi supported by a variable stroma. Smaller lesions are incidental, are often missed and carry no clinical significance. Larger lesions are associated with feto-maternal complications and are infrequently sent for histopathological examination.Methods: The study was conducted at the department of pathology, at a tertiary care obstetrics and gynaecology hospital. The study was a retrospective study which covered 7 years. Paraffin embedded blocks of placental specimens containing mass were taken up for the study. Sections were stained with haematoxylin and eosin (H and E). The results are compared and correlated with clinicopathologic factors. The statistical data are analysed manually.Results: A total of seven cases were included in the study, 4 cases were primi gravida, 1 case each in second, third and fourth gravida. Pregnancy outcome was intrauterine death in 1 case, dead born in 1 case, alive healthy children in 5 cases, birth weight was normal in 4 children, low birth weight in 2 children and 1 was extremely low birth weight. Of the total of 7 placental specimens 3 showed extraplacental mass and rest 4 showed intraplacental mass. All cases showed solitary lesions and measured > 5cm (large). Histopathological examination of all 7 specimens showed features of chorangioma.Conclusions: Careful inspection of the placenta is necessary following all deliveries. Any suspicious lesions should be documented and evaluated by histopathological examination there by predicting feto maternal complications and help the clinicians in better management of the mother and child accordingly. Meagre documentation of such cases prompted us to present this series of 7 cases of large chorangiomas with a mixed fetal outcome