Role of Human Resource Management in Sustainable Development

No Abstrac

Centuries of Heat Waves over India during 20th and 21st Century

An assessment of temperature extremes is made for the Indian subcontinent to identify the changes since 1951 to 2015, and for the future climate periods till 2100 for all the 21 CMIP5 (Coupled Model intercomparision Project phase 5) models and the representative concentration pathways RCP4.5 and RCP8.5 were examined for the period from 1 March to 31 May to characterize the heat waves in future climates and mean maximum and mean minimum bias were evaluated for the Indian subcontinent. Later two highest recorded temperature regions were chosen Northwest & Central India (NW&CIN) and only central India (CIN) box and the features of heat waves such as intensity and frequency were evaluated up to 2100. Corresponding temperature predictions from historical runs for the period 1951–2005 of 21 global CMIP model outputs and statistics were performed with the India Meteorological Department (IMD) gridded maximum temperature data for validation. Statistical metrics of BIAS, RMSE and MAE have indicated low BIAS, high correlation and high IOA (Index of Agreement) validating CMIP climate simulations. By analyzing the statistics of all the 21 models with respect to the observational gridded data from IMD came to conclusion that among all the 21 models 5 models were performing well for Indian region and having good index of agreement with IMD. The frequencies of the days having thresholds of 40 ºC, 42 ºC and 45 ºC for the maximum temperature over India during the pre-monsoon are evaluated up to 21st century. All models are showing that the intensity and frequency of heat waves were increasing significantly for both RCP4.5 and RCP8.5. Specifically, the characteristics of heat waves in terms of intensity, duration and area extent are calculated and compared to heat waves of the current climate.

Thermal analysis of Composite Laminated Plates using Higher-order shear deformation theory with Zig-Zag Function

In this paper an analytical procedure is developed to investigate the Thermal characteristics of laminated composite plates under thermal loading based on higher-order displacement model with zig-zag function, with out enforcing zero transverse shear stresses on the top and bottom faces of the laminated plates. This function improves slope discontinuities at the interfaces of laminated composite plates. The related functions are obtained using the dynamic version of principle of virtual work or Hamiltons principle. The solutions are obtained using Naviers and numerical methods for anti-symmetric cross-ply and angle-ply laminates with a specific type of simply supported boundary conditions SS-1 and SS-2. The Numerical results are presented for anti-symmetric cross-ply and angle-ply laminated plates. All the solutions presented are close agreement with the theory of elasticity and available literature

Pathways to improve the sliding wear behavior of metallic glasses: A case study of Cu- and Fe- based bulk metallic glasses

Mechanical properties of metallic glasses are quite distinct from their crystalline counterparts, which makes them attractive for several applications. Since metallic glasses exhibit high strength, hardness, and large elastic strain limits, they are expected to show superior wear resistance. The low viscosity in the super-cooled liquid region is exploited for the fabrication of metallic glasses in various shapes, for example, as high precision gears. Enhancements in the wear properties of metallic glasses are considered in this dissertation by partial devitrification and suitable micro alloying. Partial devitrification following controlled heat treatment of bulk metallic glass (BMG) provides an opportunity for microstructure control and thereby for optimizing the wear properties. There are studies showing that a small suitable alloying addition of few at. % (micro alloying) to the BMG results in an increase of the glass forming ability and also the mechanical properties, but studies on the effect of minor-alloying on wear characteristics are scarce. The focus of this dissertation is directed towards designing an optimal microstructure for enhanced wear resistance of Cu50Hf41.5Al8.5 BMG and Fe48Cr15Mo14C15B6Er2 BMG. The effect of yttrium micro alloying in the Cu-based BMG (Cu50Hf41.5−xAl8.5Y x, x =0, 2, 5, 8, 10, 15 at. %) and the erbium micro alloying in the Fe-based BMG (Fe50–xCr15Mo 14C15B6Erx, x = 1, 2 at. %) on wear properties has been studied. The role of toughness and hardness on the sliding wear properties of these metallic glasses has been examined. A critical load for crack nucleation and propagation has been computed and compared with the applied load during wear. An emphasis is also placed on the occurrence of dynamic effects such as sliding-induced crystallization and their role on the wear behavior of these metallic glasses. ^ In summary, for Cu50Hf41.5Al8.5 BMG, annealing at 510 °C for 300 min rendered a structure consisting of an amorphous matrix with uniform distribution of nano-crystalline particles with a size of 20-30 nm, revealed the best wear resistance. Sliding-induced crystallization was observed in the as-cast and structurally relaxed Cu50Hf 41.5Al8.5 BMG, which resulted in an improvement of wear behavior. Up to 5 at. %° of Y additions in Cu50Hf 41.5–xAl8.5Yx resulted in improvement of wear resistance and further additions of Y, deteriorated it. In the Fe-based BMG, addition of Er up to 2 at. % resulted in the enhancement of wear resistance and the Fe48Cr15Mo14C15B 6Er2 BMG sample, annealed for 10 min at 580 °C exhibited the best wear resistance. There was no evidence of sliding wear induced crystallization but a shear band formation was observed for the Fe-based BMG, indicating a good thermal stability of the alloy. The results demonstrate that suitable micro-alloying is an useful approach for improving the wear resistance of bulk metallic glasses and that the combination of micro-alloying and annealing can substantially improve the wear resistance.

Pathways to improve the sliding wear behavior of metallic glasses: A case study of Cu- and Fe- based bulk metallic glasses

Mechanical properties of metallic glasses are quite distinct from their crystalline counterparts, which makes them attractive for several applications. Since metallic glasses exhibit high strength, hardness, and large elastic strain limits, they are expected to show superior wear resistance. The low viscosity in the super-cooled liquid region is exploited for the fabrication of metallic glasses in various shapes, for example, as high precision gears. Enhancements in the wear properties of metallic glasses are considered in this dissertation by partial devitrification and suitable micro alloying. Partial devitrification following controlled heat treatment of bulk metallic glass (BMG) provides an opportunity for microstructure control and thereby for optimizing the wear properties. There are studies showing that a small suitable alloying addition of few at. % (micro alloying) to the BMG results in an increase of the glass forming ability and also the mechanical properties, but studies on the effect of minor-alloying on wear characteristics are scarce. The focus of this dissertation is directed towards designing an optimal microstructure for enhanced wear resistance of Cu50Hf41.5Al8.5 BMG and Fe48Cr15Mo14C15B6Er2 BMG. The effect of yttrium micro alloying in the Cu-based BMG (Cu50Hf41.5−xAl8.5Y x, x =0, 2, 5, 8, 10, 15 at. %) and the erbium micro alloying in the Fe-based BMG (Fe50–xCr15Mo 14C15B6Erx, x = 1, 2 at. %) on wear properties has been studied. The role of toughness and hardness on the sliding wear properties of these metallic glasses has been examined. A critical load for crack nucleation and propagation has been computed and compared with the applied load during wear. An emphasis is also placed on the occurrence of dynamic effects such as sliding-induced crystallization and their role on the wear behavior of these metallic glasses. ^ In summary, for Cu50Hf41.5Al8.5 BMG, annealing at 510 °C for 300 min rendered a structure consisting of an amorphous matrix with uniform distribution of nano-crystalline particles with a size of 20-30 nm, revealed the best wear resistance. Sliding-induced crystallization was observed in the as-cast and structurally relaxed Cu50Hf 41.5Al8.5 BMG, which resulted in an improvement of wear behavior. Up to 5 at. %° of Y additions in Cu50Hf 41.5–xAl8.5Yx resulted in improvement of wear resistance and further additions of Y, deteriorated it. In the Fe-based BMG, addition of Er up to 2 at. % resulted in the enhancement of wear resistance and the Fe48Cr15Mo14C15B 6Er2 BMG sample, annealed for 10 min at 580 °C exhibited the best wear resistance. There was no evidence of sliding wear induced crystallization but a shear band formation was observed for the Fe-based BMG, indicating a good thermal stability of the alloy. The results demonstrate that suitable micro-alloying is an useful approach for improving the wear resistance of bulk metallic glasses and that the combination of micro-alloying and annealing can substantially improve the wear resistance.

Concurrent Implementation of Red Black Trees

We offer Red Black Tree concurrent algorithms that logical ordering information is clearly maintained in the data structure, allowing clear separation from its physical tree architecture. With the property that an item only belongs to the tree if and only if it is an endpoint of an interval, we represent logical ordering using intervals. Thus, we are able to design lookup operations that are quick, simple, and devoid of synchronization. In this paper we implemented our Red Black Tree using Logical Ordering and evaluated the running time for insertion, Deletion and Contains Operations