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Effect of Diffuser Vane Shape on the Performance of a Centrifugal Compressor Stage

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Journal of Thermal Science 2014年第2期23卷 127-132页

作者： T ch Siva reddy GV Ramana Murty MVSSSM Prasad Sreenidhi Institute of Science and Technology GhatkesarHyderabadA.P.India Vasavi College of Engineering Hhyderabad

The present paper reports the results of experimental investigations on the effect of diffuser vane shape on the performance of a centrifugal compressor stage. These studies were conducted on the chosen stage having a back- ward curved impeller of 500 turn tip diameter and 24.5 mm width and its design flow coefficient is Фd=0.0535. Three different low solidity diffuser vane shapes namely uncarnbered aerofoil, constant thickness flat plate and circular arc cambered constant thickness plate were chosen as the variants for diffuser vane shape and all the three shapes have the same thickness to chord ratio （t/c=0.1）. Flow coefficient, polytropic efficiency, total head coeffi- cient, power coefficient and static pressure recovery coefficient were chosen as the parameters for evaluating the effect of diffuser vane shape on the stage performance. The results show that there is reasonable improvement in stage efficiency and total head coefficient with the use of the chosen diffuser vane shapes as compared to conven- tional vaneless diffuser. It is also noticed that the aero foil shaped LSD has shown better performance when com- pared to flat plate and circular arc profiles. The aerofoil vane shape of the diffuser blade is seen to be tolerant over a considerable range of incidence.

关键词： Centrifugal compressor Vaneless diffuser Low solidity diffuser

Synthesis and characterization of Y and Dy co-doped ceria solid electrolytes for IT-SOFCs:a microwave sintering

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Rare Metals 2021年第11期40卷 3329-3336页

作者： ch.Madhusudan Venkataramana Kasarapu Madhuri chittimadula Y.Suresh reddy C.Vishnuvardhan reddy Department of Physics Osmania UniversityHyderabadTelangana 500007India

In this communication,the electrical conductivities and thermal expansion studies of microwave sintered co-doped ceria Ce_(0.8)Y_(0.2-x)Dy_(x)O_(2-δ)(x=0,0.05,0.10,0.15 and 0.20) solid electrolyte materials for intermediate temperature solid oxide fuel cells(IT-SOFCs)synthesized by sol-gel auto-combustion method were *** sintering at 1300℃ for 30 min was used for making dense powder *** relative densities of all the samples are noticed above 95%.Raman spectrum was characterized by the presence of a very strong band near 460 cm^(-1),which along with X-ray diffraction(XRD) analysis ascertain the sample formation with a single-phase cubic fluorite *** lattice parameter values were calculated from XRD *** images show nearly uniform grains with distinct grain *** thermal expansion coefficients(TECs) are found to vary linearly with temperature and were measured in the range from 14.15 to 13.20×10^(-6)℃^(-1).The investigation on total ionic conductivity(TIC) was executed with variation in dopant concentration and relative oxygen *** impedance analysis reveals that the sample Ce_(0.80)Y_(0.10)Dy_(0.10)O_(2-δ) displays the highest TIC,i.e.,7.5×10^(-3) S·cm^(-1) at 500℃ and minimum activation energy 0.90 eV compared to *** the highest TIC and minimum activation energy,the Ce_(0.80)Y_(0.10)Dy_(0.10)O_(2-δ)might be the possible material as the solid electrolyte in intermediate temperature SOFCs.

关键词： Microwave sintering Ionic conductivity Co-doped ceria Solid electrolyte Intermediate temperature solid oxide fuel cells

Kinetics of hydrogen sulfide decomposition in a DBD plasma reactor operated at high temperature

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Journal of Energy chemistry 2013年第3期22卷 382-386页

作者： E.Linga reddy J.Karuppiah ch.Subrahmanyam Energy and Environmental Research Lab Department of ChemistryIndian Institute of Technology(IIT) HyderabadYeddumailaramAndhra PradeshIndia-502205

The present study investigates the kinetics of hydrogen sulfide （H2S） decomposition into hydrogen and sulfur carded out in a nonthermal plasma dielectric barrier discharge （NTP-DBD） reactor operated at ,-430 K for in situ removal of sulfur condensed inside the reactor walls. The dissociation of H2S was primarily initiated by the excitation of carder gas （At） through electron collisions which appeared to be the rate determining step. The experiments were carded out with initial concentration of H2S varied between 5 and 25 vol% at 150 mL/min （at standard temperature and pressure） flow rate in the input power range of 0.5 to 2 W. The reaction rate model based on continuous stirred tank reactor （CSTR） model failed to explain the global kinetics of H2S decomposition, probably due to the multiple complex reactions involved in H2S decomposition, whereas Michaelis-Menten model was satisfactory. Typical results indicated that the reaction order approached zero with increasing inlet concentration.

关键词： dielectric barriar discharge hydrogen sulfide kinetics temperature

Synthesis and optical characterization of porous ZnO

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Journal of Advanced Ceramics 2013年第3期2卷 260-265页

作者： K.SOWRI BABU A.RAMAchANDRA reddy ch.SUJATHA K.VENUGOPAL reddy A.N.MALLIKA Department of Physics National Institute of Technology WarangalWarangal-506004Andhra PradeshIndia

In this paper,a simple and cheap method to prepare porous ZnO by using zinc nitrate,ethanol and triethanolamine(TEA)is *** as-prepared sample consisted of nano and micro *** sample was calcined at 300℃,400℃and 500℃with different heating *** 500℃,the nano pores disappeared but the sample maintained its micro *** emission scanning electron microscopy(FE-SEM)pictures confirmed that the size and growth of ZnO nanoparticles depended on the heating *** infrared(IR)absorption peak of Zn-O stretching vibration positioned at 457 cm^(-1)was split into two peaks centered at 518 cm^(-1)and 682 cm^(-1)with the change of *** results confirmed that Fourier transform infrared(FT-IR)spectrum was sensitive to variations in particle size,shape and *** photoluminescence(PL)spectrum of porous ZnO contained five emission peaks at 397 nm,437 nm,466 nm,492 nm and 527 *** intensity enhanced monotonously with increase of temperature and the change was rapid between temperatures of 300℃and 500℃.This was due to the elimination of organic species and improvement in the crystallanity of the sample at 500℃.

关键词： semiconductors porous ZnO optical properties

Quanta-A platform for rapid control and monitoring of heterogeneous rbots

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Digital Communications and Networks 2020年第4期6卷 452-462页

作者： S.Sankhar reddy ch. Anita Agrawal Anupama K.R. E.E.E Department BITS PilaniK K Birla Goa CampusGoa403726India

Rapid prototyping,real-time control and monitoring of various events in robots are crucial requirements for research in the fields of modular and swarm robotics.A large quantities of resources(time,man power,infrastructure,etc.)are often invested in programming,interfacing the sensors,debugging the response to algorithms during prototyping and operational phases of a robot development *** cost of developing an optimal infrastructure to efficiently address such control and monitoring requirements increases significantly in the presence of mobile *** numerous solutions have been developed for minimizing the resources spent on hardware prototyping and algorithm validation in both static and mobile scenarios,it can be observed that researchers have either chosen methodologies that conflict with the power and infrastructure constraints of the research field or generated constrained solutions whose applications are restricted to the field *** paper develops a solution for addressing the challenges in controlling heterogeneous mobile robots.A platform named Quanta-a cost effective,energy efficient and high-speed wireless infrastructure is prototyped as a part of the research in the field of modular *** is capable of controlling and monitoring various events in/using a robot with the help of a light-weight communication protocol independent of the robot hardware architecture(s).

关键词： modular robotics Swarm robotics Concurrent control and monitoring Event scheduling Centralized/decentralized communication

Efficacy of low dose peginterferon alpha-2b with ribavirin on chronic hepatitis C

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World Journal of Gastroenterology 2006年第34期12卷 5554-5556页

作者： Rajesh Gupta ch Ramakrishna Sandeep Lakhtakia Manu Tandan Rupa Banerjee D Nageshwar reddy Department of Medical Gastroenterology and Hepatology Asian Institute of Gas-troenterology Somajiguda 63661 Hyderabad India

AIM: To assess the effi cacy of peginterferon alpha 2b at doses of 50 μg weekly and 80 μg weekly (based on body weight) plus ribavirin in HCV genotype 2 and genotype 3 chronic hepatitis C patients. METHODS: During the study period of Jan 2002 to Dec 2003, all patients diagnosed as chronic hepatitis C or HCV related compensated cirrhosis were treated with peginterferon alpha 2b 50 μg S/C weekly (body weight 60 kg) plus ribavirin 800 mg/d for 24 wk. RESULTS: Overall 28 patients, 14 patients in each group (based on body weight) were treated during the period. Out of 28 patients, 75% were genotype 3, 18% were genotype 2 and 7% were genotype 1. The mean dose of peginterferon alpha 2b was 0.91 μg/kg in group 1 and 1.23 μg/kg in group 2 respectively. The end of treatment and sustained virologic response rates were 82% and 78% respectively. Serious adverse effects were seen in 3.5% patients. CONCLUSION: Low dose peginterferon alpha 2b in combination with ribavirin for 24 wk is effective in HCV genotype 2 and 3 chronic hepatitis C patients.

关键词： chronic hepatitis C Peginterferon alpha 2b Ribavirin

Degradation of Methylene Blue and Rhodamine B Using a New Visible Light-Responsive Photocatalyst, KSb_2PO_(8-x)N_y

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Acta Metallurgica Sinica(English Letters) 2016年第4期29卷 335-343页

作者： G.Ravi ch.Sudhakar reddy K.Sreenu Ravinder Guje Radha Velchuri M.Vithal Department of chemistry University College of ScienceOsmania University

Potassium phosphatoantimonates, KSb2PO8 （KSbPO） and KSb2PO8-xNy （KSbPON）, are prepared by solidstate method. Urea is employed as a source of nitrogen for N-doping. Structural, morphological and optical properties of both KSbPO and KSbPON are characterized by powder X-ray diffraction （PXRD）, scanning electron microscopy, energydispersive spectroscopy, Fourier transform infrared spectroscopy and UV-visible diffuse reflectance spectroscopy. Both samples are found to crystallize in a monoclinic lattice with Cc space group. The d-lines of KSbPO and KSbPON are refined by least square fitting the PXRD data, using POWD software to obtain their unit cell parameters. The bandgap energy （Eg） of both pristine and N-doped KSbPO is found from their Kubelka-Munk plot. The KSbPON/visible photocatalytic degradation of methylene blue and rhodamine B has been investigated in aqueous heterogeneous suspension. The generation of .OH in the presence of KSbPON during the photoreaction is verified by a fluorescence technique using terephthalic acid （TA） as a probe.

关键词： Potassium phosphatoantimonates characterization Organic dyes Photodegradation

An Experimental Analysis of the Applications of Datamining Methods on Bigdata

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Journal of Autonomous Intelligence 2019年第3期2卷 31-39页

作者： ch.Naga Santhosh Kumar K.S.reddy Professor CSE ANURAG Engineering CollegeJNUTHKODADAIndia Researcher Hyderabad India

Data mining is a procedure of separating covered up,obscure,however possibly valuable data from gigantic *** Data impactsly affects logical disclosures and worth *** mining(DM)with Big Data has been broadly utilized in the lifecycle of electronic items that range from the structure and generation stages to the administration organize.A far reaching examination of DM with Big Data and a survey of its application in the phases of its lifecycle won't just profit scientists to create solid *** of late huge data have turned into a trendy expression,which constrained the analysts to extend the current data mining methods to adapt to the advanced idea of data and to grow new scientific *** this paper,we build up an exact assessment technique dependent on the standard of Design of *** apply this technique to assess data mining instruments and AI calculations towards structure huge data examination for media transmission checking *** contextual investigations are directed to give bits of knowledge of relations between the necessities of data examination and the decision of an instrument or calculation with regards to data investigation work processes.

关键词： Data Mining Big Data Knowledge Discovery Databases Decision Tree Cloud Data Mining K-Closest Neighbor Artificial Intelligence Cluster

Microstructure and pitting corrosion resistance of AA2219 Ale Cu alloy friction stir welds e Effect of tool profile

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Defence Technology（防务技术） 2015年第2期11卷 123-131页

作者： ch VENKATA RAO G.MADHUSUDHAN reddy K.SRINIVASA RAO Department of Metallurgical Engineering Andhra University Defence Metallurgical Research Laboratory

AA2219 Ale Cu alloy is widely used in defence and aerospace applications due to required combination of high strength-to-weight ratio and *** of components used for defence always involves *** though the mechanical properties of the base metal are better,but the alloy suffers from poor mechanical and corrosion properties during fusion *** overcome the problems of fusion welding,friction stir welding(FSW) is recognized as an alternative solid state joining method aimed to improve the mechanical and corrosion *** profile is one of the important variables which affect the performance of the friction stir *** the present work the effect of tool profile on the microstructure and pitting corrosion of AA2219 aluminiumecopper alloy was *** backscattered diffraction results established that the grain size and orientation of weld nugget of triangle profile is finer than that of conical *** scanning calorimetric results show the evidence of precipitate dissolution during *** was found that the microstructure changes,such as grain size and its orientation precipitate dissolution during FSW influence the hardness and corrosion *** corrosion resistance of friction stir welds of AA2219 was found to be better for triangle profile tool compared to conical profile which is attributed to material flow and strengthening precipitate morphology in various *** amount of heat generation during FSW made using triangle profile tool may be the reason for greater dissolution of strengthening precipitates in nugget zone and coarsening in thermo mechanically affected zone(TMAZ) and heat affected zone(HAZ).

关键词： Al-Cu合金搅拌摩擦焊接微观结构轮廓点蚀摩擦搅拌焊接电子背散射衍射机械性能