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Effect of Y on the Properties of Sm-Doped Ceria for IT-SOFC Applications  [PDF]
V. Venkatesh, C. Vishnuvardhan Reddy
Journal of Modern Physics (JMP) , 2013, DOI: 10.4236/jmp.2013.411181
Abstract:

The co-doped ceria-based materials with general composition formula Ce0.8-xYxSm0.2O2-δ (x = 0, 0.02, 0.04, 0.06) were prepared through the sol-gel method. The single phase of the prepared materials was confirmed by X-ray diffraction (XRD). The lattice parameters were determined by least square fitting of UNIT CELL programme. The linear variation of lattice parameter with concentration of Y into the samarium doped ceria (SDC) indicates the validity of Vegard’s law. The crystallite size of the samples obtained by using of Scherrer formula is in the range from 34 nm to 49 nm. The thermal expansion studies were carried out by using dilatometric technique in the temperature range from room temperature to 1000°C. It was observed that the thermal expansion increased linearly with increasing temperature for all the samples. The electrical conductivity was studied using impedance spectroscopy. It was observed that the composition Ce0.74Y0.06Sm0.2O2-

Solar Thermal Energy Generation Potential in Gujarat and Tamil Nadu States, India  [PDF]
C. Nagarjuna Reddy, T. Harinarayana
Energy and Power Engineering (EPE) , 2015, DOI: 10.4236/epe.2015.713056
Abstract: Government of India has come out with an ambitious target of 100 GW of using solar energy alone by the year 2022. To reach this target, innovative ideas are required to use the solar energy more effectively. For solar electricity generation, mainly two types of technologies are presently in use, namely, solar PV and solar thermal. Being a tropical country, India has large solar PV and solar thermal energy. More research is required on economic aspects to make the solar thermal competitive to solar PV. Towards this direction, in our present study we have simulated a solar thermal power plant using Parabolic Trough Collector (PTC) technology and normalized with 1 MW solar thermal power plant at Gurgaon near New Delhi. Through simulation, we have extended our study and computed the electricity generation possible at different locations of India. For this purpose with 1? × 1?spacing, computations have been carried out at 296 locations. The work is further extended for more detailed study at two representative states, namely, Gujarat and Tamil Nadu. In these two states, closer data points with 0.25? × 0.25? spacing have been considered at 273 locations for Gujarat and 197 locations for Tamil Nadu. Our results indicate a large potential of electricity generation using solar thermal energy in southern states of India, namely, Tamil Nadu, Karnataka, Kerala, southern and western part of Andhra Pradesh and eastern part of Maharashtra. Good potential has also been observed in eastern parts of Gujarat and parts of Madhya Pradesh and eastern part of Rajasthan. The annual potential ranges from 1800 MWh to as much as 2600 MWh. Major parts of northern states, for example Uttar Pradesh, Bihar, West Bengal, Punjab, Jammu and Kashmir have medium range potential. Here, the annual potential ranges from 1000 to 1500 MWh. Poor range of potential is observed towards eastern parts of India and north eastern states. Here, the electricity generation potential ranges from 600 to 1200 MWh. Our results are useful to solar thermal developer and decision managers.
Low Temperature Electrical Transport in Double Layered CMR Manganite La1.2Sr1.4Ba0.4Mn2O7  [PDF]
Y.S. Reddy, P. Kistaiah, C. Vishnuvardhan Reddy
Advances in Materials Physics and Chemistry (AMPC) , 2012, DOI: 10.4236/ampc.2012.24B014
Abstract: The electrical transport behavior and magnetoresistance (MR) of a polycrystalline double layered manganite La1.2Sr1.4Ba0.4Mn2O7, synthesized by the sol-gel method, are investigated in the temperature range 4.2 K - 300 K. The sample exhibits an insulator-to-metal transition at 87 K (TIM) and the spin-glass (SG)-like behavior is observed below 50 K (TSG). The transport behavior is analyzed in the entire temperature range considering three different regions: paramagnetic insulating region (T>TIM), ferromagnetic metallic region (TSG < T < TIM) and antiferromagnetic insulating region (TSG) by fitting the temperature dependent resistivity data to the equations governing the conduction process in the respective temperature regions. The results show that the conduction at T>TIM follows Mott variable range hopping (VRH) process, while the two-magnon scattering process is evidenced at TSG < T < TIM which is suppressed with the applied magnetic field of 4 T. The low temperature conductivity data are also fitted with Mott VRH equation. The sample exhibits a large MR (≈45%) over a temperature range     5 K – 50 K and it shows ≈32% MR at 5 K with a magnetic field of 0.5 T.
Impact of Iron Ore Tailing on Foraminifera of the Uppateru River Estuary, East Coast of India  [PDF]
Nadimikeri Jayaraju, Balam C. S. R. Reddy, Kambham Reddeppa Reddy, Addula Nallapa Reddy
Journal of Environmental Protection (JEP) , 2011, DOI: 10.4236/jep.2011.23025
Abstract: Benthic foraminiferal assemblages have been used to determine the effects of Iran ore tailing pollution on the marine environment. The present paper attempts to unveil pollution impact as responded by foraminiferal species of Uppateru estuary. The faunal data thus generated is compared with earlier data sets for possible adverse effects. There has been substantial reduction in total foraminiferal number (TFN), from 574 in 2006 to 213 in 2008 species (st.no.3) per10 gram sediment. Even the total species number (TSN) decreased from 27 in (st.no.8) 2006 to 8 (st.no.1) in 2008. Ammonia accounted for its share (68%), followed by Elphidium (7.4%) and Quinqueloculina (6.5%). These genera are considered to be robust and opportunistic type in the study area. This faunal variation in terms of density (TFN) may be owing to the pollution caused by iron ore tailing. This study also supports the view that benthic foraminiferal biota can be used as a tool to monitor marine pollution in general and estuarine environment in specific.
Effect of Ca on the Properties of Gd-Doped Ceria for IT-SOFC  [PDF]
S. Ramesh, G. Upender, K. C. James Raju, G. Padmaja, S. Mohan Reddy, C. V. Reddy
Journal of Modern Physics (JMP) , 2013, DOI: 10.4236/jmp.2013.46116
Abstract:

Ceria based electrolyte materials are very useful in intermediate-temperature solid oxide fuel cell (IT-SOFC). The compositions Ce0.85Gd0.15 - xCaxO2 - δ (x = 0.0 - 0.075) were prepared through sol-gel method. Their structure was studied by X-ray diffraction. Dense ceramic Ce0.85Gd0.15 - xCaxO2 - δ samples were prepared by sintering the pellets at 1300°C. The lattice parameter was calculated by Rietveld refinement of XRD patterns. Four probe A.C. impedance spectroscopy was used to study the total ionic conductivity of doped and co-doped ceria ceramics in the temperature range 200°C -

EXPERIMENTAL INVESTIGATIONS ON MRR AND SURFACE ROUGHNESS OF EN 19 & SS 420 STEELS IN WIREEDM USING TAGUCHI METHOD
C. BHASKAR REDDY,V. DIWAKAR REDDY,C. ESWARA REDDY
International Journal of Engineering Science and Technology , 2012,
Abstract: Quality and sophistication of the parts / products are the main requirements of the customer in the present global market. Therefore, the manufacturing / Production industries are searching for un-conventional machining processes to achieve production requirements. One among such production processes is the Wire-EDM. As such, a solemn attempt is made in this paper to investigate the response parameters, viz., Material Removal Rate (MRR) and Surface Roughness (Ra) a by experimentation on EN 19 & AISI 420 (SS420) Steels in Wire-EDM process. The Design of experiments is carried-out considering Taguchi Technique with four input parameters, namely, pulse-on, pulse-off, Bed speed and Current. The experiments are conducted considering the above two materials for L16 and then the impact of each parameter is estimated by ANOAVA. Then the regression analysis is carried-out to find the trend of the response of each material. A comparison made between the two materials indicates that the EN 19 Material is more suitable for better MRR and AISI 420 for better Surface finish.
Capacitor placement using fuzzy and particle swarm optimization method for maximum annual savings
M. Damodar Reddy,V. C. Veera Reddy
Journal of Engineering and Applied Sciences , 2008,
Abstract: This paper presents a fuzzy and Particle Swarm Optimization (PSO) method for the placement of capacitors on the primary feeders of the radial distribution systems to reduce the power losses and to improve the voltage profile. A two-stage methodology is used for the optimal capacitor placement problem. In the first stage, fuzzy approach is used to find the optimal capacitor locations and in the second stage, Particle Swarm Optimization method is used to find the sizes of the capacitors. The sizes of the capacitors corresponding to maximum annual savings are determined by considering the cost of the capacitors. The proposed method is tested on 15-bus, 34-bus and 69-bus test systems and the results are presented.
Ultrasonicated Synthesis of N-Benzyl-2,3-substituted Morpholines, via the Mitsunobu Diol Cyclisation
B. Jayachandra Reddy,M. C. Somasekhara Reddy
Journal of Chemistry , 2010, DOI: 10.1155/2010/931015
Abstract:
Real Time Monitoring of Surface Roughness by Acoustic Emissions in CNC Turning
T. S. Reddy,C. E. Reddy
Journal of Engineering Science and Technology Review , 2010,
Abstract: Machining is the most important part of the manufacturing processes. Machining deals with the process of removing materialfrom a work piece in the form of chips. Machining is necessary where tight tolerances on dimensions and finishes arerequired. The common feature is the use of a cutting tool to form a chip that is removed from the work part, called Swarf.Every tool is subjected to wear in machining. The wear of the tool is gradual and reaches certain limit of life which is identifiedwhen the tool no longer produce the parts to required quality. There are various types of wear a single point cuttingtool may be subjected to in turning. Of these, flank wear on the tool significantly affects surface roughness. The other typesof tool wears are generally avoided by proper selection of tool material and cutting conditions. On-line surface roughnessmeasurements gained significant importance in manufacturing systems to provide accurate machining. The Acoustic Emission(AE) analysis is one of the most promising techniques for on-line surface roughness monitoring. The AE signals arevery sensitive to changes in cutting process conditions. The gradual flank wear of the tool in turning causes changes in AEsignal parameters. In the present work investigations are carried for turning operation on mild steel material using HSS tool.The AE signals are measured by highly sensitive piezoelectric element; the on-line signals are suitably amplified using ahigh gain pre-amplifier. The amplified signals then recorded on to a computer and then analyzed using MAT LAB. A programis developed to measure AE signal parameters like Ring down count (RDC), Signal Rise Time and RMS voltage. Thesurface roughness is measured by roller ended linear variable probe, fitted and moved along with tool post on a CNC lathemachine. The linear movements of probe are converted in the form of continuous signals and are displayed on-line in thecomputer. The results thus plotted show a significant relation between Surface Roughness and AE signal parameters. Theconclusions are made for predicting surface roughness by suggesting consistent values and ranges for on-line monitoringAE signal parameters
OPTIMAL BLOCK REPLACEMENT MODEL FOR AIR CONDITIONERS USING HIGHER ORDER MARKOV CHAINS WITH & WITHOUT INFLATION
Y Hari Prasada Reddy,C. Nadhamuni Reddy,K. Hemachandra Reddy
International Journal of Advances in Engineering and Technology , 2012,
Abstract: This paper deals with the development of a mathematical model for the replacement of a block of items using discrete-time higher order Markov Chains. In this study, a special reference has been given to a block of Air Conditioners. In order to make the model to yield more realistic results, three intermediate states viz., Minor Repair State, Semi-Major Repair State and Major Repair States have been considered between working State & breakdown State of the system. The model is developed with an objective of optimizing the maintenance costs associated with a block of similar multi state repairable items. Transition Probabilities for future periods are estimated by Spectral Decomposition Method for First Order Markov Chain (FOMC) and Moving Weighted Transition Probabilities (MWTP) Method for Second (Higher) Order Markov Chain (SOMC). Using these probabilities, the number of Air Conditioners in each state and the corresponding average maintenance costs are computed. The forecasted inflation for Air Conditioners and the real value of money using Fisherman’s relation are employed to study and develop the real time mathematical model for block replacement decision making.
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