THD analysis for finite slider bearing with roughness: special reference to load generation in parallel sliders

This paper analyses the thermal and roughness effects on different characteristics of finite rough tilted pad slider bearings. The roughness is assumed to be stochastic, Gaussian randomly distributed. Density and viscosity are assumed to be temperature dependent. In this study, two models of one-dimensional roughness, longitudinal and transverse, are considered. The irregular domain due to roughness is mapped to a regular domain so that the numerical method can be easily applied. The modified Reynolds equation, momentum equation, continuity equation and energy equation are coupled and solved using the finite difference method to yield various bearing characteristics. It is observed that for nonparallel slider bearing the load carrying capacity due to the combined effect is less than the load capacity due to the roughness effect for both longitudinal and transverse roughness models. However, in case of a parallel pad slider bearing, the reverse is true, though the load capacity is not significant. It is also observed that the load carrying capacity due to the combined effect is larger than the load carrying capacity due to the thermal effect for both roughness models.     

Classification of rose flowers based on Fourier descriptors and color moments

Multimedia Tools and Applications - In this paper, a rose-flower variety classification scheme, using color and shape features is presented. The first three statistical moments of the R, G, and B...     

Preparation of value added composite boards using finished leather waste and plant fibers—a waste utilization effort in Ethiopia

Preparation of composite materials with better mechanical properties and agreeable use is a need of the time for the reason that it is eco-friendly. Having this objective in mind, the work of preparing value-added leather composites using finished leather waste and various plant fibers as raw materials is done in the laboratory of Council of Scientific and Industrial Research–Central Leather Research Institute, India. In the leather goods and footwear manufacturing industries, about 20–30% of leather is discarded as waste, and presently it is imperative to make effort to utilize this waste in Ethiopia because it is huge and untapped resource. The recycled leather (RCL) as control and its composite boards (CBs) which are the mixtures of leather fibers with plant fibers like jute (Corchorus trilocularis L.), hibiscus (Hibiscus cannabinus), sisal (Agave sisalana), palm (Phoenix dactylifera) and enset (Ensete ventricosum) in the proportion of 10, 20, 30, and 40% are characterized for their physicochemical properties (tensile strength, elongation at break, stitch tear strength, water absorption, water desorption, and flexing strength), scanning electron microscope (SEM), Fourier transform infrared, thermogravimetric analysis (TGA), and differential scanning calorimeter (DSC). Composites exhibited better mechanical properties compared to those of control boards. SEM pictures showed the composite nature of the boards. TGA studies revealed better thermal stability for composites. In the DSC study, the CBs of RCL-S and RCL-P exhibited higher melting point values than those of RCL-J, RCL-H, and RCL-E samples. Based on these results, all the composite boards may be used as raw material for the preparation of consumer products such as insoles, chapel-uppers, wallets, light hand bags, mouse pads, roofing, wall partitioning, and components of furniture and interior decorations.     

Identification of system vulnerabilities in the Ethiopian electric power system

The Ethiopian Electric Power(EEP) has been operating and managing the national interconnected power system with dispersed and geographically isolated generators, a complex transmission system and loads. In recent years, with an increasing load demand due to rural electrification and industrialization, the Ethiopian power system has faced more frequent, widely spread and long lasting blackouts. To slash the occurrence of such incidents, identifying the system vulnerabilities is the first step in this direction. In this paper, the vulnerability assessment is performed using indices called active power performance index(PIp) and voltage performance index(PIv). These indices provide a direct means of comparing the relative severity of the different line outages on the system loads and voltage profiles. Accordingly, it is found that the most severe line outages are those lines that interconnect the high load centered(Addis Ababa and Central regions) with the rest of the regional power systems. In addition, the most vulnerable buses of the network in respect of voltage limit violations are mainly found at the high load centers.     

Bayesian transformed models for small area estimation

Sample surveys are usually designed and analyzed to produce estimates for larger areas. However, sample sizes are often not large enough to give adequate precision for small area estimates of interest. To overcome such difficulties,borrowing strength from related small areas via modeling becomes an appropriate approach. In line with this, we propose hierarchical models with power transformations for improving the precision of small area predictions. The proposed methods are applied to satellite data in conjunction with survey data to estimate mean acreage under a specified crop for counties in Iowa.     

Strategies to enhance the reliability of flow quantile prediction in the gauged and ungauged basins

The precise reproduction of different flow regimes in both gauged and ungauged watersheds is crucial for managing environmental flow and water quality requirements. However, the ability of hydrological models to reproduce flow quantiles (FQs) is often influenced by the process of calibrating the most dominant parameters through traditional parameter estimation methods. This research proposes a systematic parameter estimation approach to improve the credibility of the hydrologic model in reproducing FQs in gauged and ungauged watersheds through the following steps: (a) implementation of parameter sensitivity analysis to identify the dominant parameters, (b) initial estimation of the sensitive parameter values, (c) an iterative search for the optimal value of the dominant parameter in reproducing FQs and (d) regionalization of parameters to estimate FQs in the ungauged watersheds. The analysis shows the highest sensitivity of the runoff curve number (CN2) in simulating the hydrologic process in all test watersheds. Moreover, the best value of CN2 was found to be different for each flow quantile. Therefore, CN2 was updated for reproduction of FQs, which resulted in an overall average improvement of the regionalized model accuracy (across all test watersheds and flow quantiles) by 37 and 46% during the calibration and validation periods, respectively. The spatiotemporal dynamics of the water balance components that often control the behaviours of FQs in both the gauged and ungauged watersheds were also quantified. The results show a wide range of spatiotemporal variations for the majority of the water balance components.