Design Analysis of Brushless Direct Current Generator

In this work, optimisation of a brushless direct current (BLDC) generator design was undertaken by carrying out an electromagnetic and computational fluid dynamic study. The studies were carried out for different loading-overloading conditions and angular speeds, keeping in consideration the required electrical and thermal parameters, firstly for the initial design and then for optimised designs. In the initial phase, transient electromagnetic simulations were done using Ansys Maxwell to estimate power output, flux densities, heat losses et al. In the next phase, steady state conjugate heat transfer simulations using frozen rotor method for rotating domains were carried out in Ansys CFX using the heat loss values obtained from electromagnetic study in the first phase. The results from conjugate heat transfer were obtained in the form of temperature and flow parameters. After a thorough study and comparison of the results for different designs, obtained in the two phases, it was seen one of the optimised designs showed better electromagnetic, thermal and flow parameters as compared to the initial design and satisfied all the optimum electrical and thermal parameters

Probabilistic Assessment of Drought Characteristics using a Hidden Markov Model

Droughts are evaluated using drought indices that measure the departure of meteorological and hydrological variables such as precipitation and stream flow from their long-term averages. While there are many drought indices proposed in the literature, most of them use pre-defined thresholds for identifying drought classes ignoring the inherent uncertainties in characterizing droughts. In this study, a hidden Markov model (HMM) [1] is developed for probabilistic classification of drought states. The HMM captures space and time dependence in the data. The proposed model is applied to assess drought characteristics in Indiana using monthly precipitation and stream flow data. The comparison of HMM based drought index with standard precipitation index (SPI) [2] suggests that the HMM index provides more intuitive results

Adding New Tasks to a Single Network with Weight Transformations using Binary Masks

Visual recognition algorithms are required today to exhibit adaptive abilities. Given a deep model trained on a specific, given task, it would be highly desirable to be able to adapt incrementally to new tasks, preserving scalability as the number of new tasks increases, while at the same time avoiding catastrophic forgetting issues. Recent work has shown that masking the internal weights of a given original conv-net through learned binary variables is a promising strategy. We build upon this intuition and take into account more elaborated affine transformations of the convolutional weights that include learned binary masks. We show that with our generalization it is possible to achieve significantly higher levels of adaptation to new tasks, enabling the approach to compete with fine tuning strategies by requiring slightly more than 1 bit per network parameter per additional task. Experiments on two popular benchmarks showcase the power of our approach, that achieves the new state of the art on the Visual Decathlon Challenge

Prognostic factors for lymph node metastasis from upper gingival carcinomas

This study sought to identify tumor characteristics that associate with regional lymph node metastases in squamous cell carcinomas originating in the upper gingiva

COLORECTAL CANCER AND ITS RISK FACTORS AMONG PATIENTS ATTENDING A TERTIARY CARE HOSPITAL IN SOUTHERN KARNATAKA, INDIA

Objective: To determine the association between certain socio-demographic and life style factors with colorectal cancer.Methods: This case-control study was conducted using a pre-designed questionnaire among 100 incident colorectal cancer patients and 200 unmatched controls attending a tertiary care hospital in southern Karnataka. Cases and the controls were interviewed and details regarding their socio-demographic factors were collected. Information on lifestyle factors such as dietary habits, physical activity levels and substance use were documented. They were also assessed for presence of existing co-morbidities and family history of colorectal and other cancers. Multivariable logistic regression was performed to determine the association between various risk factors and colorectal cancer.Results: In the present hospital based study, mean age of the participants was less than 55 years. Sixty three percent of the cases and 54.5% of the controls were males. On multivariable analysis age ≥50years (OR=1.87; 95%CI=1.02-3.45), low physical activity (OR=5.66; 95%CI=3.10-10.34) and low frequency of fruits consumption (OR=4.10; 95%CI=2.21-7.50) and hypertension (OR= 4.65; 95% CI=1.32-16.44) showed a positive association with colorectal cancer.Conclusion: Promoting healthy dietary practices and physical activity among the middle aged population appears to be significant in the context of colorectal cancer prevention in the Indian subcontinent.Keywords: Colorectal cancer, Case–control, Risk factors, Lifestyle, Comorbidities

Effect of Magnetic Steering of the Arc on Clad Quality in Submerged Arc Strip Cladding Magnetic steering of the arc is demonstrated to improve corrosion resistance and microstructure while minimizing dilution

ABSTRACT. Submerged arc strip cladding is often used when thickness of clad material is required. The productivity of this process has been improved by the use of higher welding currents and wider strips. The associated problems were arc blow, increased penetration and poor bead characteristics. Dilution is the parameter that controls almost all qualities of cladding. Magnetic steering reduces penetration, and hence, dilution and arc blow control. Stainless steel cladding on mild steel is often used to impart corrosion resistance. In such situations, the clad quality is specified by corrosion resistance, ferrite content and good fusion between clad metal and base metal. This paper discusses results of an investigation on the effect of an oscillating magnetic field used to steer the arc in submerged arc strip cladding using 60 X 0.5-mm 309L stainless steel strips, with varying magnetizing flux intensity and dwell time. The resulting test pieces were evaluated for parameters that imparted the best clad quality and the results indicate the following: 1) Magnetic steering of the arc reduces dilution and corrosion rate. 2) Magnetic steering of the arc permits use of higher currents for a given dilution •level, thus increasing productivity

Development of a roller quenching apparatus for the production of amorphous phases

The details of an apparatus designed to produce amorphous phases by rapid quenching from the melt are described. A drop of molten material is squeezed between two copper rollers rotating against each other at 5000 RPM and a thin foil of the material is produced. The system produces cooling rates of the order of 105 K/sec. Details of the development and construction are mentioned

In silico assessment of potential druggable pockets on the surface of α1-Antitrypsin conformers

The search for druggable pockets on the surface of a protein is often performed on a single conformer, treated as a rigid body. Transient druggable pockets may be missed in this approach. Here, we describe a methodology for systematic in silico analysis of surface clefts across multiple conformers of the metastable protein α1-antitrypsin (A1AT). Pathological mutations disturb the conformational landscape of A1AT, triggering polymerisation that leads to emphysema and hepatic cirrhosis. Computational screens for small molecule inhibitors of polymerisation have generally focused on one major druggable site visible in all crystal structures of native A1AT. In an alternative approach, we scan all surface clefts observed in crystal structures of A1AT and in 100 computationally produced conformers, mimicking the native solution ensemble. We assess the persistence, variability and druggability of these pockets. Finally, we employ molecular docking using publicly available libraries of small molecules to explore scaffold preferences for each site. Our approach identifies a number of novel target sites for drug design. In particular one transient site shows favourable characteristics for druggability due to high enclosure and hydrophobicity. Hits against this and other druggable sites achieve docking scores corresponding to a Kd in the µM–nM range, comparing favourably with a recently identified promising lead. Preliminary ThermoFluor studies support the docking predictions. In conclusion, our strategy shows considerable promise compared with the conventional single pocket/single conformer approach to in silico screening. Our best-scoring ligands warrant further experimental investigation