Sleep Medicine Education in India: Policy Initiatives of National Academy of Medical Sciences (India)

The article discusses the role of National academy of Medical Sciences in initiating policy for sleep education and research in India through the NAMS Regional symposium and its further dissemination through various academic research

Carrier Transport in High Mobility InAs Nanowire Junctionless Transistors

Ability to understand and model the performance limits of nanowire transistors is the key to design of next generation devices. Here, we report studies on high-mobility junction-less gate-all-around nanowire field effect transistor with carrier mobility reaching 2000 cm2/V.s at room temperature. Temperature-dependent transport measurements reveal activated transport at low temperatures due to surface donors, while at room temperature the transport shows a diffusive behavior. From the conductivity data, the extracted value of sound velocity in InAs nanowires is found to be an order less than the bulk. This low sound velocity is attributed to the extended crystal defects that ubiquitously appear in these nanowires. Analyzing the temperature-dependent mobility data, we identify the key scattering mechanisms limiting the carrier transport in these nanowires. Finally, using these scattering models, we perform drift-diffusion based transport simulations of a nanowire field-effect transistor and compare the device performances with experimental measurements. Our device modeling provides insight into performance limits of InAs nanowire transistors and can be used as a predictive methodology for nanowire-based integrated circuits.Comment: 22 pages, 5 Figures, Nano Letter

Evaluation of Tribological Properties of Transesterified Cottonseed Oil by Adding Silicon Dioxide (SiO2) as an Additive

The usage of vegetable oils has increased in many applications as they possess desirable lubrication properties. However, the use is limited due to poor tribological properties. Many researchers have attempted to explore the performance of various vegetable oils and the effect of adding anti-wear additives on tribological properties. In the present work, bio lubricant is obtained from pure cottonseed oil (CSO). Silicon Dioxide, a useful catalyst, is used as an anti-wear additive. Oleic Acid surface-modified Silicon Dioxide (OA-SiO2) is added at 0.25%, 0.5%, 0.75%, and 1% weight concentrations in transesterified cottonseed oil (TCSO). After the addition of OA-SiO2 nanoparticles, the improvement in the lubrication properties has been seen. A four-ball tester is used to measure the coefficient of friction (COF) and wear scar diameter (WSD) of CSO, TCSO, and additive-added TCSO as per ASTM standard D 4172. Friction and wear tests reveal that the TCSO with OA-SiO2 nanoparticles shows better tribological properties. It is observed that WSD and COF of TCSO are reduced by 11.85 % and 24.88 % respectively by adding 0.75 weight % of OA-SiO2 nanoparticles. Present work shows that TCSO, on adding OA-SiO2 additives, can be a strong alternative for mineral oil

Evaluation of Tribological Properties of Transesterified Cottonseed Oil by adding Silicon Dioxide (SiO2) as an additive

The usage of vegetable oils has increased in many applications as they possess desirable lubrication properties. However, the use is limited due to poor tribological properties. Many researchers have attempted to explore the performance of various vegetable oils and the effect of adding anti-wear additives on tribological properties. In the present work, bio lubricant is obtained from pure cottonseed oil (CSO). Silicon Dioxide, a useful catalyst, is used as an anti-wear additive. Oleic Acid surface-modified Silicon Dioxide (OA-SiO2) is added at 0.25%, 0.5%, 0.75%, and 1% weight concentrations in transesterified cottonseed oil (TCSO). After the addition of OA-SiO2 nanoparticles, the improvement in the lubrication properties has been seen. A four-ball tester is used to measure the coefficient of friction (COF) and wear scar diameter (WSD) of CSO, TCSO, and additive-added TCSO as per ASTM standard D 4172. Friction and wear tests reveal that the TCSO with OA-SiO2 nanoparticles shows better tribological properties. It is observed that WSD and COF of TCSO are reduced by 11.85 % and 24.88 % respectively by adding 0.75 weight % of OA-SiO2 nanoparticles. Present work shows that TCSO, on adding OA-SiO2 additives, can be a strong alternative for mineral oil

Coexistence of breast hemangioma with fibroadenoma: a rare case report

Vascular tumors of the breast are uncommon and include angiosarcomas and hemangiomas. Angiosarcomas are more common and benign hemangiomas are rare. We report a case of 16 years old female patient with hemangioma of breast coexisting with very commonly occurring breast fibroadenoma. The rarity of literature on breast hemangioma especially coexistent with fibroadenoma, and its importance in differentiation from the more common malignant counterpart, the angiosarcomas deserves mention

Nonlinear Aerodynamic Damping of Sharp-Edged Beams at Low Keulegan-Carpenter Numbers

Slender sharp-edged flexible beams such as flapping wings of micro air vehicles (MAVs), piezoelectric fans and insect wings typically oscillate at moderate-to-high values of non-dimensional frequency parameter β with amplitudes as large as their widths resulting in Keulegan–Carpenter (KC) numbers of order one. Their oscillations give rise to aerodynamic damping forces which vary nonlinearly with the oscillation amplitude and frequency; in contrast, at infinitesimal KC numbers the fluid damping coefficient is independent of the oscillation amplitude. In this article, we present experimental results to demonstrate the phenomenon of nonlinear aerodynamic damping in slender sharp-edged beams oscillating in surrounding fluid with amplitudes comparable to their widths. Furthermore, we develop a general theory to predict the amplitude and frequency dependence of aerodynamic damping of these beams by coupling the structural motions to an inviscid incompressible fluid. The fluid–structure interaction model developed here accounts for separation of flow and vortex shedding at sharp edges of the beam, and studies vortex-shedding-induced aerodynamic damping in slender sharp-edged beams for different values of the KC number and the frequency parameter β. The predictions of the theoretical model agree well with the experimental results obtained after performing experiments with piezoelectric fans under vacuum and ambient conditions

VUV PROPERTIES OF Eu3+- DOPED YBO3 PHOSPHOR PREPARED VIA ALDO-KETO AND SOLID-STATE PROCESS

The Eu3+ doped YBO3 was prepared by the novel aldo-keto method. The structure and VUV luminescence properties of the title compound were studied and compared to the corresponding properties of the materials prepared by a conventional solid state reaction. The use of novel aldo-keto method in preparation lowered the reaction threshold temperature by c.a. 300oC. The YBO3 phosphor from the aldo-keto method look like evenly sized spherical structures, whereas those from the solid-state process look like some agglomerates of little spheres. The Eu3+-doped YBO3 phosphors prepared by both methods showed the red emission with peak around 592, 611 and 627 nm at excitations wavelengths 147 and172 nm, which corresponds to the transitions from the excited 5D0 level to the 7FJ (J = 1, 2, 3, 4) levels of Eu3+ activators. However, the emission intensity of the Eu3+ doped YBO3 from the aldo-keto system is about 2 times as much as that from the sold-state process

Clinicopathological study of salivary gland tumors: An observation in tertiary hospital of central India

Background: The salivary glands are one of the few tissues in the body that are subjected to diverse and heterogeneous range of tumors and tumor like conditions. The relative infrequency of these tumors makes their diagnosis and management quite complicated. Fine needle aspiration cytology (FNAC) is a useful diagnostic procedure which has a recognized role in the evaluation of salivary gland lesions. A pre-operative diagnosis about nature of lesion, whether benign or malignant, will help in making decision about proper management of patient.Objective: Aim of this study was to know the epidemiology of salivary gland tumors in our region and to evaluate sensitivity, specificity and diagnostic accuracy of fine needle aspiration cytology taking histopathology as the gold standard. Method: It was prospective observational study conducted in department of pathology in our institute. Total 100 cases were studied with particular reference to age, sex, site, cytologic details & histological types as per WHO classification. FNAC & histopathological examination was done in all cases. Correlation between cytological & histopathological diagnoses was assessed. Diagnostic accuracy of FNAC was evaluated by comparing cytological & histopathological diagnoses.Results: Parotid gland was the most common site of involvement (70% cases). Maximum number of patients was in age range of 41-50 years & male to female ratio was 0.8:1. Most common benign & malignant tumors were pleomorphic adenoma (69.89% cases) & mucoepidermoid carcinoma (8.60% cases) respectively. On cytology, 93 cases while on histopathology 96 cases were diagnosed as neoplastic. Cytological diagnoses correlated with histopathological diagnoses in 94% cases. Sensitivity, specificity & diagnostic accuracy of FNAC were found to be 96.87%, 100% & 96% respectively. Conclusion: FNAC in salivary gland masses is fairly reliable for correct preoperative diagnosis. Multiple sampling and special attention to cytologic features should help to minimize errors.