High hydrogen content syngas fuel burning in lean premixed spherical flames at elevated pressures: Effects of preferential diffusion

This study addresses the effects of preferential diffusion on flame structure and propagation of high hydrogen content (HHC) turbulent lean premixed hydrogen-carbon monoxide syngas flames at elevated pressures. The direct numerical simulations with detailed chemistry were performed in three-dimensional domain for expanding spherical flame configuration in a constant pressure combustion chamber. To identify the role of preferential diffusion on flame structure and propagation under low and high turbulence levels at elevated pressure, simulations were performed at an initial turbulent Reynolds number of 15 and 150 at a pressure value of 4 bar. The results demonstrate that the thermo-diffusive instability greatly influences the lean premixed syngas cellular flame structure due to strong preferential diffusion effects under low turbulence level at elevated pressure. In contrast, the results reveal that the thermo-diffusive effects are destabilising and preferential diffusion is overwhelmed by turbulent mixing under high turbulence level at elevated pressure. This finding suggests that the development of cellular flame structure is dominated by turbulence with little or no contribution from the thermo-diffusive instability for the lean premixed syngas flame which operates under conditions of high turbulence and elevated pressures. However, results demonstrate that the flame acceleration and species diffusive flux are still influenced by the preferential diffusion for the lean premixed syngas flame which operates under conditions of high turbulence and elevated pressures

Constrictive pericarditis in a post–renal transplant patient: a case report

INTRODUCTION: Constrictive pericarditis is a rare complication in the post–renal transplant period. It poses a diagnostic dilemma even in the modern era. Its incidence is not known and tuberculosis is implicated in some of the cases. CASE PRESENTATION: A 54-year-old Sri Lankan man, in the sixth year of transplant presented with resistant ascites, shortness of breath and elevated creatinine from the baseline. Pre-transplant he was empirically treated for tuberculosis pericarditis and was on isoniazid prophylaxis for 1 year following transplantation. Two-dimensional echocardiography and cardiac catheterization confirmed the diagnosis, and pericardiectomy was performed, which resulted in full resolution of the symptoms as well as the graft function. The histology or bacteriology failed to demonstrate features suggestive of tuberculosis in the surgical specimen. CONCLUSION: In constrictive pericarditis, a causative factor is difficult to find. Isoniazid prophylaxis shows benefit in preventing tuberculosis-associated constrictive pericarditis

New early Eocene tapiromorph perissodactyls from the Ghazij Formation of Pakistan, with implications for mammalian biochronology in Asia

Early Eocene mammals from Indo-Pakistan have only recently come under study. Here we describe the first tapiromorph perissodactyls from the subcontinent. Gandheralophus minor n. gen. and n. sp. and G. robustus n. sp. are two species of Isectolophidae differing in size and in reduction of the anterior dentition. Gandheralophus is probably derived from a primitive isectolophid such as Orientolophus hengdongensis from the earliest Eocene of China, and may be part of a South Asian lineage that also contains Karagalax from the middle Eocene of Pakistan. Two specimens are referred to a new, unnamed species of Lophialetidae. Finally, a highly diagnostic M3 and a molar fragment are described as the new eomoropid chalicothere Litolophus ghazijensis sp. nov. The perissodactyls described here, in contrast to most other mammalian groups published from the early Eocene of Indo-Pakistan, are most closely related to forms known from East and Central Asia. Tapiromorpha are diverse and biochronologically important in the Eocene there and our results allow the first biochronological correlation between early Eocene mammal faunas in Indo-Pakistan and the rest of Asia. We suggest that the upper Ghazij Formation of Pakistan is best correlated with the middle or late part of the Bumbanian Asian Land-Mammal Age, while the Kuldana and Subathu Formations of Pakistan and India are best correlated with the Arshantan Asian Land-Mammal Age

High Redshift Supernova Rates

We use a sample of 42 supernovae detected with the Advanced Camera for Surveys on-board the Hubble Space Telescope as part of the Great Observatories Origins Deep Survey to measure the rate of core collapse supernovae to z~0.7 and type Ia supernovae to z~1.6. This significantly increases the redshift range where supernova rates have been estimated from observations. The rate of core collapse supernovae can be used as an independent probe of the cosmic star formation rate. Based on the observations of 17 core collapse supernovae, we measure an increase in the core collapse supernova rate by a factor of 1.6 in the range 0.3<z<0.7, and an overall increase by a factor of 7 to z~0.7 in comparison to the local core collapse supernova rate. The increase in the rate in this redshift range in consistent with recent measurements of the star formation rate derived from UV-luminosity densities and IR datasets. Based on 25 type Ia supernovae, we find a SN Ia rate that is a factor 3-5 higher at z~1 compared to earlier estimates at lower redshifts (z<0.5), implying that the type Ia supernova rate traces a higher star formation rate at redshifts z>1 compared to low redshift. At higher redshift (z>1), we find a suggested decrease in the type Ia rate with redshift. This evolution of the Ia rate with redshift is consistent with a type Ia progenitor model where there is a substantial delay between the formation of the progenitor star and the explosion of the supernova. Assuming that the type Ia progenitor stars have initial main sequence masses 3-8 M_Sun, we find that 5-7% of the available progenitors explode as type Ia supernovae.Comment: 16 pages, 3 figures, accepted for publication in the Astrophysical Journa

The Real Symplectic Groups in Quantum Mechanics and Optics

text of abstract (We present a utilitarian review of the family of matrix groups $Sp(2n,\Re)$, in a form suited to various applications both in optics and quantum mechanics. We contrast these groups and their geometry with the much more familiar Euclidean and unitary geometries. Both the properties of finite group elements and of the Lie algebra are studied, and special attention is paid to the so-called unitary metaplectic representation of $Sp(2n,\Re)$. Global decomposition theorems, interesting subgroups and their generators are described. Turning to $n$-mode quantum systems, we define and study their variance matrices in general states, the implications of the Heisenberg uncertainty principles, and develop a U(n)-invariant squeezing criterion. The particular properties of Wigner distributions and Gaussian pure state wavefunctions under $Sp(2n,\Re)$ action are delineated.)Comment: Review article 43 pages, revtex, no figures, replaced because somefonts were giving problem in autometic ps generatio

Threshold Temperatures and Thermal Requirements for the Development of Spodoptera litura (Lepidoptera: Noctuidae)

Developmental thresholds and thermal requirements for different stages of Spodoptera litura (F.) fed on groundnut leaves were determined under constant laboratory conditions and in the field. An average of 64 degree-days (DD) above a threshold of 8°C was required from oviposition to egg hatch; the larval period required 303 DD and pupal stage 155 DD above a 10°C threshold; females needed 29 DD above a 10.8°C threshold from emergence to oviposition. Fifth and sixth instars accounted for about 50%of the total larval requirement under laboratory and field conditions. The response of various stages of S. litura to temperatures under constant laboratory conditions was similar to that under field conditions. The upper developmental threshold temperature of all stages was 37°C; 40°C was lethal

Simultaneous Measurements of Star Formation and Supermassive Black Hole Growth in Galaxies

Galaxies grow their supermassive black holes in concert with their stars, although the relationship between these major galactic components is poorly understood. Observations of the cosmic growth of stars and black holes in galaxies suffer from disjoint samples and the strong effects of dust attenuation. The thermal infrared holds incredible potential for simultaneously measuring both the star formation and black hole accretion rates in large samples of galaxies covering a wide range of physical conditions. Spitzer demonstrated this potential at low redshift, and by observing some of the most luminous galaxies at z~2. JWST will apply these methods to normal galaxies at these epochs, but will not be able to generate large spectroscopic samples or access the thermal infrared at high-redshift. An order of magnitude gap in our wavelength coverage will persist between JWST and ALMA. A large, cold infrared telescope can fill this gap to determine when (in cosmic time), and where (within the cosmic web), stars and black holes co-evolve, by measuring these processes simultaneously in statistically complete and unbiased samples of galaxies to z>8. A next-generation radio interferometer will have the resolution and sensitivity to measure star-formation and nuclear accretion in even the dustiest galaxies. Together, the thermal infrared and radio can uniquely determine how stars and supermassive blackholes co-evolve in galaxies over cosmic time

Objective structured practical examination (OSPE) as a tool in formative assessment of II MBBS students, in pathology

Background: Assessment drives the student learning. Regular periodical assessment not only improves learning habits, but also enhances the competence in all levels of medical education. Traditional practical examination is more subjective. It depends on examiners subjectivity, varying difficulty level of various experiments, and also internal marks variation etc. These flaws can be overcome by newer methods like OSPE. The aim of the study was to implement OSPE as a tool of internal assessment for practical skills in the II MBBS. To compare this with traditional practical examination (TPE). To obtain the students and faculty feedback regarding OSPE as a tool of assessment.Methods: A cross sectional study was carried out for 158 students in II internal pathology practical examination for six days in the second week of September 2016 at Department of Pathology, Dr. Pinnamaneni Siddhartha institute of medical sciences & Research Foundation, Chinnaoutpalli. Faculty and students were sensitized; blueprint were used to arrange twenty OSPE stations for the exercises conducted as per TPE and for the same 25 marks as per TPE. Simultaneously, all the students were subjected to both TPE and OSPE at the same time and venue. TPE was assessed by two professors and OSPE by separate eight faculty members independently without interaction with the students. The procedural stations were evaluated by using checklist and the response stations which consisted of short answers and MCQs, facilitated correction. Feedback was given to the student on their performance and feedback was obtained from the students and faculty regarding OSPE by questionnaire with Yes/No answers.Results: Performance score of students in OPSE (13.73 ±2.49) was higher as compared to TPE (9.27±1.86) which was statistically significant. Based on the response to the questionnaire, students perception towards OSPE was analyzed. Majority strongly agree OSPE to be fairer, more transparent and objective in comparison to TPE. In contrast, all the faculty members unanimously opined that OSPE was difficult to arrange, time taken and faculty versus students ratio was high for evaluation. Though, the faculty (91%) overall opined that OSPE should be included as a method of assessment.Conclusions: Present study revealed that OSPE was acceptable, feasible and reliable to the students as well as for faculty for the internal assessment in pathology. Opinions of both students and faculties strongly agreed that OPSE is more effective objective assessment tool

World review of the natural enemies and diseases of Spodoptera litura(F.)(Lepidoptera: Noctuidae)

Published information was used to compile a summary of natural enemies(parasitoids, predatorsand diseases) reported attacking Spodoptera litirra (F) under field conditions. Species (71) of insect parasitoids in seven families of Hymenoptera and two families of Diptera were listed as parasitoids of difTerent stages of S. litura. Predatory insects (36) belonging to 14 families and 12 species of spiders from six families have been reported to feed on this species. Four prolozoan, four fungal, seven bacterial, four each of viral and nematode species were also reported to be the pathogens of this species. Published information suggested that periodic releases of large number of egg parasites could help in suppressing populalions of this pest. There is a considerable scope for increased attention to the role of natural enemies as component of integrated pest management programmes of S. litura