Environmental over enthusiasm

India needs large dams for water storage, hydropower and flood control. It also needs long-distance inter-basin water transfers. However, India has a complex and strict environmental regulatory system which ignores a developing economy's needs and peoples' aspirations and is often impractical. This is used by activists to thwart infrastructure building, and, when faced with development slowdown, the government tries to thwart the laws they themselves have made. India's food, water and energy security, economic, and poverty-alleviation plans are in jeopardy unless environmental regulators realize that the regulations are being misused and that environmental over-enthusiasm is benefiting neither development nor the environment.     

Effect of pH on the detailed chemical nature and metal-carbonate species in as synthesized zirconia alumina composites

Zirconia was deposition precipitated on γ-alumina in pH range 7-10 from zirconium oxy-nitrate and soda ash. Zirconium formed its hydroxycarbonate as deduced from ICP-EOS, CHN, and TGA-MS. Higher pH favored formation of carbonate species of zirconium over its hydroxide. TGA-MS indicated formation of three different types of carbonate species. FTIR results corroborated this. Monodentate metal carbonate was observed irrespective of pH of preparation. In addition, bridged bidentate species formed at pH ≤ 8 which changed to chelating bidentate at pH > 8. XRD indicated that all the samples formed tetragonal-zirconia upon calcination irrespective of pH of preparation. Higher pH resulted in smaller crystallites of t-ZrO₂. Changes in chemical moiety with pH reflected on acidity and the deactivation rate for 2-methyl-3-butyn-2-ol which decreased by two orders of magnitude in samples prepared at higher pH. Surface area and pore volume benefited from deposition precipitation. SEM-EDAX showed reasonable distribution of zirconia over γ-Al₂O₃.     

Design and fabrication of thermoelectric waste heat reutilization system—possible industrial application

The current article discussed the detail design and development of an experimental test rig to derive usable energy by utilizing the waste heat energy through a heat exchanger made of Bi₂Te₃ material. The accuracy including the efficiency of the fabricated device is demonstrated further by verifying the associated parameter through a simulation model (commercial finite element package, ANSYS 15.0). To imitate the waste hot air from the industry is achieved via a heat gun and fed to the test rig for the generation of thermoelectric power. The simulation model accuracy has been demonstrated by juxtaposing the associated experimental data and computational readings. Subsequently, the feasibility and optimum range of design parameters are established by comparing the experimental and the simulation data (triggered temperature difference, voltage output, and heat flux) generated at the interface of the thermoelectric power generators. In addition, the coefficient of determination (R²) value has been evaluated statistically and verified with the current experimental results for the demonstration of the relevancy. The statistical study shows the existence of the correlation between the current experimental and the simulation model. Also, the experimental result indicates the possible implementation of the newly developed system for the recovery from the waste heat either the automobile exhaust or any other kind of dissipated heat from the industries.     

Studies on ballistic parameters of di-butyl phthalate-coated triple base propellant used in large caliber artillery gun ammunition

Triple base propellant (TBP) containing mainly nitrocellulose, nitroglycerine, and nitroguanidine has been manufactured and coated with plasticizer in the present work. The aim was to study ballistics of di-butyl phthalate (DBP)-coated TBP. DBP solution in ethanol containing nitrocellulose dope was used for coating onto the propellant grains. DBP-deterred propellant showed inhibition to burning, resulting in lowering the values of ballistic parameters namely peak pressure (P_max), dP_max, pressure index (α), and burning rate coefficient (β) during closed vessel firing. Increase in percentage of DBP in coating solution led to further decrease in ballistic parameters. Dynamic evaluation of the surface-moderated propellant showed comparatively lower muzzle velocity and chamber pressure for deterred propellant batches without leaving any unburnt particles in gun chamber at subzero temperatures with the lowest possible charge mass. The DBP-coated propellant can be useful in 155-mm artillery gun to achieve higher loading density as it has lower flame temperature and chamber pressure as compared to uncoated propellant which will result in increasing barrel life due to reduction in the barrel erosion.     

Dynamic Spectrum Access with QoS and Interference Temperature Constraints

Spectrum is one of the most precious radio resources. With the increasing demand for wireless communication, efficiently using the spectrum resource has become an essential issue. With the Federal Communications Commission's (FCC) spectrum policy reform, secondary spectrum sharing has gained increasing interest. One of the policy reforms introduces the concept of an interference temperature - the total allowable interference in a spectral band. This means that secondary users can use different transmit powers as long as the sum of these power is less than the interference threshold. In this paper, we study two problems in secondary spectrum access with minimum signal to interference noise ratio (quality of service (QoS)) guarantee under an interference temperature constraint. First, when all the secondary links can be supported, a nonlinear optimization problem with the objective to maximize the total transmitting rate of the secondary users is formulated. The nonlinear optimization is solved efficiently using geometric programming techniques. The second problem we address is, when not all the secondary links can be supported with their QoS requirement, it is desirable to have the spectrum access opportunity proportional to the user priority if they belong to different priority classes. In this context, we formulate an operator problem which takes the priority issues into consideration. To solve this problem, first, we propose a centralized reduced complexity search algorithm to find the optimal solution. Then, in order to solve this problem distributively, we define a secondary spectrum sharing potential game. The Nash equilibria of this potential game are investigated. The efficiency of the Nash equilibria solutions are characterized. It is shown that distributed sequential play and an algorithm based on stochastic learning attain the equilibrium solutions. Finally, the performances are examined through simulations     

Prediction of hopper discharge rate using combined discrete element method and artificial neural network

An Artificial Neural Network (ANN) was developed to predict the mass discharge rate from conical hoppers. By employing Discrete Element Method (DEM), numerically simulated flow rate data from different internal angles (20°–80°) hoppers were used to train the model. Multi-component particle systems (binary and ternary) were simulated and mass discharge rate was estimated by varying different parameters such as hopper internal angle, bulk density, mean diameter, coefficient of friction (particle-particle and particle-wall) and coefficient of restitution (particle-particle and particle-wall). The training of ANN was accomplished by feed forward back propagation algorithm. For validation of ANN model, the authors carried out 22 experimental tests on different mixtures (having different mean diameter) of spherical glass beads from different angle conical hoppers (60° and 80°). It was found that mass discharge rate predicted by the developed neural network model is in a good agreement with the experimental discharge rate. Percentage error predicted by ANN model was less than ±13%. Furthermore, the developed ANN model was also compared with existing correlations and showed a good agreement.     

Study of saw-tooth chip in machining of Inconel 718 by metallographic technique

The present research work aims to understand the chip formation mechanisms in Inconel 718 machining through metallographic technique. The influence of machining speed on shear band and chip shape have been analyzed. Characterization of the shear band has been conducted by analyzing the shear band thickness, strain, strain rate, stress and micro-hardness. Additionally, chip reduction coefficient parameters and chip segmentation ratio parameters have been analyzed to understand the type of chip formation at various machining speeds. The observations and analysis of the same indicated that the formation of the saw-tooth chip is due to high-strain localization within the chip and crack initiation at the free surface of the chip. Thinner shear bands are observed at higher machining speed (120 m/min), and thicker shear bands are observed at lower machining speed (40 m/min). The magnitude of chip segmentation parameters indicates that crack generation increases with increase in machining speed.     

Effect of Dopants and Sintering Method on the Properties of Ceria-Based Electrolytes for IT-SOFCs Applications

Doped and co-doped ceria ceramics are used as electrolyte materials in solid oxide fuel cells. In this work, ceria-based oxides, Ce_0.90Gd_0.06Y_0.02M_0.02O_2?δ (M?=?Ca, Fe, La, and Sr) were prepared by conventional as well as microwave processing from the precursors prepared by the mixed oxide method. The consolidated calcined powders in pellet form were sintered in microwave energy at 1400°C for 20 min and in an electric furnace of IR radiation at 1400°C for 6 h. The x-ray diffraction analysis confirmed that all the compositions were crystallized into a cubic fluorite structure. Surface morphology of the sintered products was studied using scanning electron microscopy and the microhardness was investigated using the Vickers hardness test. The comparative results analysis shows that the microwave-sintered samples have uniform grain growth, higher density and higher microhardness than the corresponding conventionally sintered products. The microwave-sintered sample of composition Ce_0.90Gd_0.06Y_0.02Sr_0.02O_2?δ was found to have the highest microhardness among the four compositions due to its high density and smallest grain size.     

Structural and Luminescence Studies on Barium Sodium Borosilicate Glasses Containing Uranium Oxides

Barium sodium borosilicate glasses containing different amounts of uranium oxides were prepared by conventional melt quench method and investigated for their structural aspects by ²⁹Si and ¹¹B MAS NMR technique combined with steady‐state luminescence and lifetime measurements. Based on MAS NMR studies, it is confirmed that uranium ions act as network modifier up to 15 wt% and beyond which a separate uranium containing phase is formed. From the luminescence studies, it is inferred that uranyl species is in a highly distorted environment. For more than 15 wt% uranium oxide incorporation, weaker U–O–U linkages are formed at the expense stronger U–O–Si/B linkages, as suggested by the excited state lifetime value of the uranyl species as well as red shift in emission peak maximum. For glass samples containing more than 25 wt% uranium oxides, crystalline barium uranium silicate gets phase separated from glass matrix as confirmed by XRD studies.     

The state of the art in intelligent real-time FMS control: a comprehensive survey

Flexible manufacturing systems (FMS) have been developed with the hope that they would provide a means to tackle a threefold challenge — better quality, lower cost and shorter lead times — by integrating machine tools, robots, material handling and storage systems, and computers. Control of the integrated system presented a new set of problems as well as challenges, which have been receiving considerable attention from the academic community as well as from industrial system users. Intelligent control, which involves using computers to assist in decision making at various stages of the control process, has been advocated by many researchers as a possible avenue to reach a solution to these problems. This paper provides a review of the state of the art in intelligent control of FMS, in an attempt to supplement earlier general reviews via a more focused perspective. The principles of several techniques, namely simulation, knowledge based, example based, petri nets, and hybrid approaches are briefly introduced, and publications are reviewed, followed by discussions ontheir potential. Suggestions for further research and development are also enumerated.