Asymmetric diffusion at the interfaces in multilayers

Nanoscale diffusion at the interfaces in multilayers plays a vital role in controlling their physical properties for a variety of applications. In the present work depth-dependent interdiffusion in a Si/Fe/Si trilayer has been studied with sub-nanometer depth resolution, using x ray standing waves. High depth-selectivity of the present technique allows one to measure diffusion at the two interfaces of Fe namely, Fe-on-Si and Si-on-Fe, independently, yielding an intriguing result that Fe diffusivity at the two interfaces is not symmetric. It is faster at the Fe-on-Si interface. While the values of activation energy at the two interfaces are comparable, the main difference is found in the pre-exponent factor suggesting different mechanisms of diffusion at the two interfaces. This apparently counter-intuitive result has been understood in terms of an asymmetric structure of the interfaces as revealed by depth selective conversion electron Mossbauer spectroscopy. A difference in the surface free energies of Fe and Si can lead to such differences in the structure of the two interfaces.Comment: 4 pages, 5 figure

Interface induced perpendicular magnetic anisotropy in Co/CoO/Co thin film structure: An in-situ MOKE investigation

Co /CoO/Co polycrystalline film was grown on Si (001) substrate and magnetic properties have been investigated using in-situ magneto-optic Kerr effect during growth of the sample. Magnetic anisotropy with easy axis perpendicular to the film surface has been observed in top Co layer, whereas bottom layer was found to be soft with in-plane magnetization without any influence of top layer. Ex-situ in-plane and out-of-plane diffraction measurements revealed that the growth of Co on oxidized interface takes place with preferential orientation of c-axis perpendicular to the film plane, which results in the observed perpendicular magnetic anisotropy. Texturing of the c-axis is expected to be a result of minimization of the interface energy due to hybridization between Co and oxygen at the interface.Comment: 9 pages, 3 figures, under review in IOP journa

Influence of rice varieties and fertility levels on performance of rice and soil nutrient status under aerobic conditions

Scarcity of water resources in India is limiting the production of flooded rice crop. A field experiment was conducted in factorial RBD with sixteen treatment combinations including four rice varieties viz. V1: PR-115, V2: DRRH-3, V3: PAC-837 and V3: PR-121 and four fertility levels viz. F1: control (N0P0K0), F2: N, P2O5, K2O at 90: 45: 22.5 kg ha-1, F3: N, P2O5, K2O at 120:60:30 kg ha-1 and F4: N, P2O5, K2O at 150: 75: 37.5 kg ha-1 replicated thrice. The results revealed that among the different varieties, PAC-837 recorded highest plant height and number of tillers m-2 at all the growth stages. All yield attributes viz. number of effective tillers m-2, number of seeds per panicle, 1000-grain weight, spikelet sterility and grain yield, straw yield and harvest index significantly differed in different varieties and were recorded highest in PAC-837 which were however, statistically at par with DRRH-3 except grain yield and effective tillers m-2. Rice variety PAC-837 recorded highest grain yield of 45.65 q ha-1 and straw yield of 59.98 q ha-1. Among the fertility levels, number of effective tillers m-2 significantly increased up to 120: 60: 30 N-P2O5-K2O kg ha-1 thereafter nonsignificant differences were noticed. The grain and straw yield increased up to 150: 75: 37.5 N-P2O5-K2O kg ha-1 and recoded grain yield of 52.78 q ha-1 and straw yield of 73.85 q ha-1 with application of 150:75:37.5 N-P2O5-K2O kg ha-1. Nutrient application of 150: 75: 37.5 N-P2O5-K2O kg ha-1 recorded highest available N (238.16 kg ha-1), P (16.18 kg ha-1) and K (163.25 kg ha-1) in soil after harvest of the crop. Higher available nitrogen (235.28 kg ha-1), phosphorus (16.38 kg ha-1) and potassium (154.24 kg ha-1) n soil were recorded with PR-121 and lowest available major nutrients were recorded with variety PAC-837. This study would help to introduction and adaptation of new rice variety PAC-837 with application of 150: 75: 37.5 N-P2O5-K2O kg ha-1 under aerobic conditions in Shiwalik foothills region of North-Western Himalayas

Carotid Endarterectomy vs. Carotid Stenting: Fairly Comparable or Unfairly Compared?

A commentary on Stenting versus endarterectomy for treatment of carotid-artery stenosis. by Thomas G. Brott et al. (2010). CREST Trial. N. Engl. J. Med. May 26. (10.1056/ NEJMoa0912321) Carotid revascularization with carotid endarterectomy (CEA) has been shown to be superior to medical therapy for stroke prevention in symptomatic and asymptomatic patients with moderate to severe stenosis who meet well defined medical and surgical selection criteria. The benefit of CEA is significantly higher in symptomatic compared to asymptomati

Study of the hormonal and reproductive factors associated with low back pain in reproductive female

Background: Low back pain related disability and work absence accounts for high economical costs in modern society. A prevalence of 28-80% has been found with increase of prevalence with age and female preponderance.Methods: The present study was conducted on 250 non pregnant women complaining of low back pain attending department at Upper India Sugar Exchange Maternity Hospital, Department of Obstetrics and Gynaecology, GSVM Medical College, Kanpur during the period of one year. A brief questionnaire was used to screen, among the respondents, the occurrence of low back pain in the past year.Results: Low back pain was associated with high BMI, high waist circumference, more number of children, irregular and prolonged duration of menstruation, young maternal age at first birth and with history of abortion.Conclusions: Hormonal and reproductive factors are associated with low back pain.

Raman Signatures of Strong Kitaev Exchange Correlations in (Na1−x_{1-x}Lix_x)2_2IrO3_3 : Experiments and Theory

Inelastic light scattering studies on single crystals of (Na$_{1-x}$Li$_x$)$_2$IrO$_3$ ($x = 0, 0.05$ and $0.15$) show a polarization independent broad band at $\sim$~2750 cm$^{-1}$ with a large band-width $\sim 1800$~cm$^{-1}$. For Na$_2$IrO$_3$ the broad band is seen for temperatures $\leq 200$~K and persists inside the magnetically ordered state. For Li doped samples, the intensity of this mode increases, shifts to lower wave-numbers and persists to higher temperatures. Such a mode has recently been predicted (Knolle et.al.) as a signature of the Kitaev spin liquid. We assign the observation of the broad band to be a signature of strong Kitaev-exchange correlations. The fact that the broad band persists even inside the magnetically ordered state suggests that dynamically fluctuating moments survive even below $T_{N}$. This is further supported by our mean field calculations. The Raman response calculated in mean field theory shows that the broad band predicted for the spin liquid state survives in the magnetically ordered state near the zigzag-spin liquid phase boundary. A comparison with the theoretical model gives an estimate of the Kitaev exchange interaction parameter to be $J_K\approx 57$~meV.Comment: 14pages 4 figure

Biofuel production potential from wastewater in India by integrating anaerobic membrane reactor with algal photobioreactor

The authors would like to express sincere gratitude towards the Director, Birla Institute of Technology and Science, Pilani K. K. Birla Goa Campus for the support in using the institutional infrastructure for the development of this paper.Peer reviewedPostprin

Impact of COVID-19 on Patients’ Attitudes and Perceptions of Dental Health Services: A Questionnaire Based Study in an Australian University Dental Clinic

COVID-19, the global pandemic, has significantly interrupted the provision of oral health care to many individuals. This study aims to evaluate patients’ attitudes to and perceptions of dental visits in the COVID-19 pandemic and assess if socio-economic status influences their perception of risk associated with dental visits. Patients attending the dental clinic were invited to participate in this study by completing a questionnaire administered in August 2021. Composite indicators for access, attitude, perception and socio-economic status were created based on subsets of questions. A total of 247 completed questionnaires were obtained. Analysis was performed with the perception, attitude and access indicators against the socio-economic status indicator. This study found that there is a statistically significant difference between socio-economic groups and their attitudes and perceptions around dental health care services in the current COVID-19 pandemic. Individuals from lower socio-economic status groups were less influenced by the pandemic. Participants from higher socio-economic status groups were found to be more cautious around COVID-19 and its risks