Properties of intermetallic Ni–Al coatings deposited by high-velocity air–fuel spraying

Powder Metallurgy and Metal Ceramics - The formation of intermetallic Ni–Al coatings by high-velocity air–fuel (HVAF) spraying is considered. The energy states of particles are...     

Modified room temperature solid-state synthesis of yttria-stabilized zirconia(YSZ) nano-powders for solid oxide fuel cells

High-performance solid oxide fuel cell(SOFC) is in urgent need of high-quality electrolyte powders with high reactivity and chemical uniformity.Here,8 mol% Y₂O₃ doped ZrO₂(YSZ) nano-powders were synthesized by an improved solid-state reaction method at ambient temperature,and were applied to the fabrication of SOFC electrolytes.YSZ nano-powders show average grain sizes of ～20 nm and high dispersibility,which is comparable with or even better than some other chemi...     

Does intrinsic motivation fuel the prosocial fire? Motivational synergy in predicting persistence, performance, and productivity.

Researchers have obtained conflicting results about the role of prosocial motivation in persistence, performance, and productivity. To resolve this discrepancy, I draw on self-determination theory, proposing that prosocial motivation is most likely to predict these outcomes when it is accompanied by intrinsic motivation. Two field studies support the hypothesis that intrinsic motivation moderates the association between prosocial motivation and persistence, performance, and productivity. In Study 1, intrinsic motivation strengthened the relationship between prosocial motivation and the overtime hour persistence of 58 firefighters. In Study 2, intrinsic motivation strengthened the relationship between prosocial motivation and the performance and productivity of 140 fundraising callers. Callers who reported high levels of both prosocial and intrinsic motivations raised more money 1 month later, and this moderated association was mediated by a larger number of calls made. I discuss implications for theory and research on work motivation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Preparation methods and production of initial materials to prepare gadolinium oxide pellets used in fabrication of composite uranium–gadolinium fuel

The production method of efficient composite uranium–gadolinium fuel, the application of which will make it possible to improve the technical and economic performance of nuclear power plants, is developed in a laboratory. Based on the analysis of results, the substantiation of implementing the proposed method in industrial conditions is performed. Methods for the preparation and production of the initial materials to prepare gadolinium oxide are described. Necessary characteristics of the pellets of the promising composite uranium–gadolinium fuel are established in the course of experiments, and final requirements for these pellets are formulated allowing for them.     

Synthesis and characterization of Dy-Eu-Tm co-doped cubic phase stabilized bismuth oxide based electrolytes in terms of intermediate temperature-solid oxide fuel cells(IT-SOFCs)

In this study,a new Dy-Eu-Tm co-doped cubic phase stabilized bismuth oxide solid electrolyte system was synthesized by using solid-state reaction method in atmospheric conditions.Before conductivity measurements,X-ray diffraction(XRD) pro files of the annealed samples show that created mixtures have heterogeneous phase,but after conductivity measurements,the face-centered cubic(FCC) crystal structure is stabilized for all samples.Also,the increase in total dopant rate causes an increase in full ...     

Novel LaFe2O4 spinel structure with a large oxygen reduction response towards protonic ceramic fuel cell cathode

Highly active and stable electrocatalysts are mandatory for developing high-performance and longlasting fuel cells.The current study demonstrates a high oxygen reduction reaction(ORR) electrocatalytic activity of a novel spinel-structured LaFe₂O₄ via a self-doping strategy.The LaFe₂O₄ demonstrates excellent ORR activity in a protonic ceramic fuel cell(PCFC) at temperature range of 350-500℃.The high ORR activity of LaFe₂O₄ is mainl...     

Preparation and characterization of Ce_(0.8)La_(0.2–x)Y_xO_(1.9) as electrolyte for solid oxide fuel cells

In this study, ultrafine Ce0.8La0.2–x Y x O1.9（for x=0, 0.05, 0.10, 0.15, 0.20） powders were successfully prepared by the sol-gel method.The samples were characterized by fourier transform infrared（FTIR）, thermogravimetric and differential scanning calorimetry（TG-DSC）, X-ray diffraction（XRD）, scanning electron microscopy（SEM）, AC impedance and thermal expansion measurements.Experimental results indicated that highly phase-pure cubic fluorite electrolyte Ce0.8La0.2–x Y x O1.9 powders were obtained after calcining at 600 °C.The as-synthesized powders exhibited high sintering activity, the Ce0.8La0.2–x Y x O1.9 series electrolytes which have higher relative densities over 96% could be obtained after sintered at 1400 °C for 4 h.Ce0.8La0.15Y0.05O1.9 electrolyte sintered at 1400 °C for 4 h exhibited higher oxide ionic conductivity（σ800 oC=0.057 S/cm）, lower electrical activation energy（E a=0.87 e V） and moderate thermal expansion coefficient（TEC=15.5×10-6 K-1, temperature range 25–800 °C）.     

Study of creep deformation of irradiated zircaloy cladding by isothermal heating of irradiated PHWR fuel pins in temperature range 700°C–900°C

Fuel pins removed from actual irradiated fuel bundles discharged from Pressurised Heavy Water Reactors (PHWRs) have been used for experimental study of high temperature creep deformation as functions of cladding temperature and internal fission gas pressure. Experiment consisted of localized heating of 100 mm long segment of the fuel pins in a furnace in inert atmosphere at temperatures 700°C, 800°C, 850°C and 900°C for 10–15 minutes. The internal pressure and the total void volume in the fuel pins were estimated by puncture test on sibling pins from the same fuel bundle. After the heating experiment the diameter of the pin along the length was measured to obtain the diameter increase due to high temperature creep. Analysis of the experimental data for fuel pins with internal pressure 0.55 ± 0.05 MPa, provided the following empirical correlation for creep rate of the cladding as a function of temperature Creep rate (s^?1) = 2.23 × 10¹⁰ × exp (?305500/RT), for temperatures in the range of 800°C–900°C, where, R is gas constant, 8.314 J/mol K and T is temperature in K. For fuel pins with different internal fission gas pressures, the correlation obtained for the cladding strain as a function of internal pressure (at room temperature) was $$ \begin{gathered} Cladding strain = 118.22 \times 10^{ - 3} exp (0.53P), for temperature = 900^\circ C \hfill \\ where, P is the internal pressure in MPa at room temperature. \hfill \\ \end{gathered} $$ This paper presents the details of the experiment and the results.     

Cone-shaped cylindrical Ce_（0.9）Gd_（0.1）O_（1.95） electrolyte prepared by slip casting and its application to solid oxide fuel cells

A cone-shaped gadolinium doped ceria(Ce0.9Gd0.1O1.95,GDC) electrolyte cylinder with a thin wall was fabricated using slip cast-ing technique.The diameter of the larger open end of the cone-shaped cylinder was 0.85 cm,the length was 1.0 cm,and the thickness of the wall was 0.026 cm after sintering.Both the electrolyte and electrode powders were fabricated by using a glycine-nitrate process.A single solid oxide fuel cell(SOFC) was prepared with the cone-shaped electrolyte,NiO-GDC(70:30 wt.%) anode and Sm0.5Sr0.5CoO3(SSC) cathode.Its electrochemical performance(I-V curve) and electrochemical impedance spectroscopy(EIS) were studied with humidified hydrogen as the fuel and air as the oxidant.The maximum output power density was about 300 ?mW/cm2 at 700 oC.The EIS results showed that the dominant loss of the SOFC was from the ohmic resistance of the electrolyte.     

Cerium and ruthenium co-doped La_(0.7)Sr_(0.3)FeO_(3-δ) as a high-efficiency electrode for symmetrical solid oxide fuel cell

Symmetrical solid oxide fuel cells(SSOFCs) could be alternative energy conversion devices due to their simple fabrication process and low cost.Herein,perovskite La_(0.6)Ce_(0.1)Sr_(0.3)Fe_(0.95)Ru_(0.05)O_(3-δ)(LCSFR) was synthesized and evaluated as a high-performance electrode for SSOFCs based on the electrolyte of La_(0.9)Sr_(0.1)Ga_(0.8)Mg_(0.2)O_(3-δ)(LSGM).LCSFR retains their stable perovskite crystal structure in both reducing and oxidizing atmospheres,though a minor amount of LaSrFeO_4 phase is present under reducing conditions.Morphology investigation shows that homogeneously dispersed Ru metallic nanoparticles are exsolved on the surface of LCSFR after being reduced.The polarization resistance(R_p) of LCSFR-CGO(Ce_(0.9)Gd_(0.1)O_(2-δ)) is about 0.11 Ω·cm~2 at 800℃ in air,while the value of R_p for LCSFR-CGO in wet H_2(3% H_2 O) increases up to 0.32 Ω·cm~2.The symmetrical LCSFR-CGOILSGMILCSFR-CGO cell demonstrates a performance with an open circuit potential(OCV) of 1.07 V and a maximum peak power density of 904 mW/cm~2 at 800℃ using wet H_2 as the fuel.This high performance indicates that LCSFR is a candidate electrode for SSOFCs.