scholarly journals Single-Cell Tests to Explore the Reliability of Sofc Installations Operating Offshore

Energies ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1624
Author(s):  
Nelson Thambiraj ◽  
Ivar Waernhus ◽  
Crina Suciu ◽  
Arild Vik ◽  
Alex C. Hoffmann
Keyword(s):  
Cell Structure ◽  
Oxygen Depletion ◽  
X Ray Diffraction ◽  
Short Term ◽  
Sem Images ◽  
Cathode Degradation ◽  
Air Supply ◽  
Different Temperatures ◽  
Effect Of Oxygen

This paper studies the robustness of off-shore solid oxide fuel cell (SOFC) installations and the nature and causes of possible cell degradation in marine environments. Two important, cathode-related, impediments to ensuring SOFC reliability in off-shore installations are: cathode degradation due to salt contamination and oxygen depletion in the air supply. Short-term and long-term tests show the effect of salt contamination in the cathode feed on cell performance, and reveal the underlying cause of the degradation seen. SEM/X-ray Diffraction/(XRD) analyses made it possible to identify salt taken up in the cathode microstructure after the short-term testing while the macroscopic cell structure remained intact after the short-term tests. The long-term degradation was found to be more severe, and SEM images showed delamination at the cathode/electrolyte interface with salt present, something that was not seen after long-term testing without salt. The effect of oxygen depletion on the performance was also determined at three different temperatures using I-V curves.

scholarly journals Neural Architecture Search for a Highly Efficient Network with Random Skip Connections

2020 ◽  
Vol 10 (11) ◽  
pp. 3712
Author(s):  
Dongjing Shan ◽  
Xiongwei Zhang ◽  
Wenhua Shi ◽  
Li Li
Keyword(s):  
State Of The Art ◽  
Cell Structure ◽  
Frequency Discrimination ◽  
Search Space ◽  
Short Term ◽  
Cell Parameters ◽  
Neural Architecture ◽  
Proposed Model ◽  
Initialization Scheme

Regarding the sequence learning of neural networks, there exists a problem of how to capture long-term dependencies and alleviate the gradient vanishing phenomenon. To manage this problem, we proposed a neural network with random connections via a scheme of a neural architecture search. First, a dense network was designed and trained to construct a search space, and then another network was generated by random sampling in the space, whose skip connections could transmit information directly over multiple periods and capture long-term dependencies more efficiently. Moreover, we devised a novel cell structure that required less memory and computational power than the structures of long short-term memories (LSTMs), and finally, we performed a special initialization scheme on the cell parameters, which could permit unhindered gradient propagation on the time axis at the beginning of training. In the experiments, we evaluated four sequential tasks: adding, copying, frequency discrimination, and image classification; we also adopted several state-of-the-art methods for comparison. The experimental results demonstrated that our proposed model achieved the best performance.

THE INFLUENCE OF SYNTHESIZING TEMPERATURES ON THE PROPERTIES OF THE Cu/Sn/ZnS PRECURSOR THIN FILMS

2015 ◽  
Vol 22 (01) ◽  
pp. 1550009
Author(s):  
YA MING SUN ◽  
DONG LONG ◽  
XIANG CHENG MENG ◽  
ZHONG HUA ◽  
BO LI ◽  
...  
Keyword(s):  
Thin Films ◽  
Soda Lime ◽  
Soda Lime Glass ◽  
Wave Band ◽  
X Ray Diffraction ◽  
Sem Images ◽  
Different Temperatures ◽  
Microstructure Morphology ◽  
Uv Visible ◽  
Precursor Thin Film

Cu 2 ZnSnS 4 thin films were prepared on soda-lime glass by sulfurization of the Cu / Sn / ZnS precursors. The microstructure, morphology and optical properties of the films were investigated by X-ray diffraction (XRD), Raman scattering (Raman), scanning electron microscopy (SEM) and UV-visible spectrophotometer (UV-Vis). The SEM images of the precursor and the thin films annealed at different temperatures are very different due to their different surface products. The absorption spectrum shifts to high-wave band region with increasing annealing temperatures. The precursor thin film annealed at 500°C for 2 h forms a single CZTS phase with kesterite structure and the bandgap is estimated to be 1.54 eV.

Effect of Temperature on the Purity, Particle Size and Morphology of Fe2O3 Nanomaterials

2014 ◽  
Vol 895 ◽  
pp. 305-308 ◽  
Author(s):  
Abdul Rahman Noor Azreen ◽  
Norlida Kamarulzaman ◽  
Nurhanna Badar ◽  
Mustaffa Nur Amalina ◽  
Kamarudin Norashikin
Keyword(s):  
Effect Of Temperature ◽  
X Ray Diffraction ◽  
Sem Images ◽  
Xrd Pattern ◽  
Weak Organic Acid ◽  
Irregular Shapes ◽  
Three Samples ◽  
Different Temperatures ◽  
Particle Size And Morphology ◽  
Size And Morphology

Iron Oxide, Fe2O3, has extensively been studied by many researchers because of their important uses for various applications such as magnetic storages, catalysts, anode, gas sensors and biomedical applications. In our work, Fe2O3 have been synthesized via a new self-propagating combustion (SPC) route using a weak organic acid as an oxidant. The precursor was annealed at three different temperatures. Three samples of Fe2O3 heated at 300 °C, 600 °C and 800 °C for 24 hours were characterized using X-Ray Diffraction (XRD) and Field Emission Scanning Electron Microscopy (FESEM). The XRD pattern confirms that the crystal structure for both 600 °C and 800 °C samples are rhombohedral while for the 300 °C sample, rhombohedral and cubic phases are present. The SEM images showed that the 300 °C and 600 °C materials have irregular shapes. For the 800 °C sample the materials seem to be more crystalline with individual polyhedral shapes.

Behavior of UO2 in the RBMK-1000 Spent Fuel under Oxidizing Conditions

2004 ◽  
Vol 824 ◽  
Author(s):  
A. B. Kolyadin ◽  
V. Ya. Mishin ◽  
K. Ya. Mishin ◽  
A. S. Aloy ◽  
T. I. Koltsova
Keyword(s):  
Thermal Oxidation ◽  
Spent Nuclear Fuel ◽  
Oxidation Process ◽  
Spent Fuel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Dry Storage ◽  
Different Temperatures ◽  
Xrd Techniques

AbstractThe oxidation of UO2–type spent nuclear fuel (SNF) in gaseousmedia was studied at different temperatures and oxygen contents using gravimetric and powder X-ray diffraction (XRD) techniques. The aim of the study was to determine the mechanism(s) of thermal-oxidation alteration of SNF during long-term dry storage. The samples used in the experiments were chips of RBMK-1000 fuel rods.Oxidation of UO2with a mean burn-up of 10.7 and 19.73 MW d/kg in humid air was observed at a temperature as low as 150°C. At 200°C nearly all of the UO2was transformed into U3O8 between 3500-4000 hours. In a humid nitrogen environment containing of 0.05-1.3 vol. % oxygen at 300°C, the UO2 completely transformed to U3O8 between 2500-3000 hours. Oxidation of UO2in samples with small amounts of jacket damage (e.g., <0.04 MM2)ll progresses more slowly and after â3000 hours the oxygen-to-uranium ratio was 2.56.Stabilization of the oxidation process was not observed in the fuel samples upto an O/U ratio of 2.4, which may be attributed to the smallburn-up of the fuel under investigation.

scholarly journals Effects of annealing parameters on phase, structure and thermochromic properties of VO2 (M) derived from nanostructured VO2(B)

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Hamdi Muhyuddin Barra ◽  
Soo Kien Chen ◽  
Nizam Tamchek ◽  
Zainal Abidin Talib ◽  
Oon Jew Lee ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Phase Transition ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Sem Images ◽  
X Ray ◽  
Thermogravimetric Analyzer ◽  
Different Temperatures ◽  
Thermochromic Properties ◽  
Scanning Electron

Abstract Synthesis of thermochromic VO2 (M) was successfully done by annealing hydrothermally-prepared VO2 (B) at different temperatures and times. Conversion of the metastable VO2 (B) to the thermochromic VO2 polymorph was studied using thermogravimetric analyzer (TGA) under N2 atmosphere. Moreover, the phase and morphology of the synthesized samples were studied using X-ray diffraction (XRD) and field-emission scanning electron microscopy (FE-SEM), respectively. Accordingly, the XRD scans of all the annealed samples exhibited the presence of monoclinic VO2 (M), while the FE-SEM images of the samples showed the formation of nanorods and nanospheres, particularly those heated at high temperatures (650 °C and 700 °C). Meanwhile, differential scanning calorimetry (DSC) was used to measure the phase transition temperature (τc), hysteresis, and enthalpy of the prepared VO2. Based on these results, all samples displayed a τc of about 66 °C. However, the hysteresis was high for the samples annealed at lower temperatures (550 °C and 600 °C), while the enthalpy was very low for samples heated at lower annealing time (1.5 h and 1 h). These findings showed that crystallinity and nanostructure formation affected the thermochromic properties of the samples. In particular, the sample annealed at 650 °C showed better crystallinity and improved thermochromic behavior.

Optical Properties of Nano-CuInSi Thin Films Prepared by Multilayer Synthesized Method

2011 ◽  
Vol 403-408 ◽  
pp. 1094-1098
Author(s):  
Jian Sheng Xie ◽  
Ping Luan ◽  
Jin Hua Li
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Film Surface ◽  
X Ray Diffraction ◽  
Sem Images ◽  
X Ray ◽  
N2 Atmosphere ◽  
Double Beam ◽  
Absorption Studies ◽  
Different Temperatures

Thin Nano-CuInSi films have been prepared by multilayer synthesized method using magnetron sputtering technology, and followed by annealing in N2 atmosphere at different temperatures. The structures of CuInSi films were detected by X-ray diffraction(XRD); X-ray diffraction studies of the annealed films indicate the presence of CuInSi, the peak of main crystal phase is at 2θ=42.450°; the morphology of the film surface was studied by SEM. The SEM images show that the crystalline of the film prepared by multilayer synthesized method was granulated. The transmittance (T) spectra of the films were measured by Shimadzu UV-2450 double beam spectrophotometer. The calculated absorption coefficient is larger than 105 cm−1 when the wavelength is shorter than 750 nm. The band gap has been estimated from the optical absorption studies and found to be about 1.47 eV, but changes with purity of CuInSi. CuInSi thin film is a potential absorber layer material applied in solar cells and photoelectric automatic control.

Influence of temperature on the activity of anammox granular biomass

2016 ◽  
Vol 73 (10) ◽  
pp. 2518-2525 ◽  
Author(s):  
D. Sobotka ◽  
K. Czerwionka ◽  
J. Makinia
Keyword(s):  
Removal Rate ◽  
Batch Reactor ◽  
Effect Of Temperature ◽  
Short Term ◽  
Temperature Range ◽  
Batch Tests ◽  
Different Temperatures ◽  
Effects Of Temperature ◽  
Granular Biomass

The aim of this study was to determine a short-term and long-term effect of temperature on the anammox rate and determination of temperature coefficients in the Arrhenius and Ratkowsky equations. The short-term effects of temperature on the anammox granular biomass were investigated in batch tests at ten different temperatures in the range of 10–55 °C. The maximum overall nitrogen removal rate of 1.3 gN gVSS−1·d−1 was observed at 40 °C (VSS: volatile suspended solids). The minimum rate, close to 0 gN gVSS−1·d−1, was observed for the limits of the analyzed temperature range (10 and 55 °C). The activity tests carried out at 55 °C showed an irreversible loss of the activity due to the observed biomass lysis. Subsequently to the batch tests, a sequencing batch reactor (SBR) was operated at different temperatures (from 30 to 11 °C) to determine the long-term effects of temperature. The system was successfully operated at 15 °C, but when temperature was decreased to 11 °C, nitrite started to accumulate and the system lost its stability. The temperature coefficient (θ) was 1.07 for the batch tests carried out in the temperature range of 10–40 °C. In contrast, during the long-term SBR operation, substantially different θ had to be estimated for two temperature ranges, 1.07 (T = 15–30 °C) and 1.65 (T = 11–15 °C).

Alkaloid variations in Catharanthus roseus seedlings treated by different temperatures in short term and long term

2007 ◽  
Vol 18 (4) ◽  
pp. 313-315 ◽  
Author(s):  
Xiao-rui Guo ◽  
Lei Yang ◽  
Jing-hua Yu ◽  
Zhong-hua Tang ◽  
Yuan-gang Zu
Keyword(s):  
Catharanthus Roseus ◽  
Short Term ◽  
Different Temperatures

Combustion Synthesis of the MgAl2O4 Using Glycerin from the Production of Biodiesel

2014 ◽  
Vol 775-776 ◽  
pp. 682-686 ◽  
Author(s):  
Graziela Guzi de Moraes ◽  
Luiza Bonin ◽  
Elisangela Guzi de Moraes ◽  
Karina Donadel ◽  
Kaio Barp ◽  
...  
Keyword(s):  
Combustion Synthesis ◽  
Direct Reaction ◽  
Particle Sizes ◽  
X Ray Diffraction ◽  
Sem Images ◽  
Laser Scattering ◽  
Direct Route ◽  
Particle Size Analyzer ◽  
Different Temperatures ◽  
Product Powder

This work aims to investigate the glycerin from the biodiesel as fuel in the combustion synthesis into two routes, one for high temperature called direct route, in order to inhibit the formation of acrolein and compare it with the conventional combustion synthesis at low temperatures, using as fuels saccharose, pure glycerin, pure glycerin gel, glycerin from biodiesel, biodiesel from glycerin dried 24 h, biodiesel from glycerin gel dried 24 h to obtain the magnesium aluminate spinel (MgAl2O4). The synthesis was performed from the mixture of the precursors (Al (NO3)3.9H2O and Mg (NO3)2.6H2O) in water with the addition of the fuels. In the direct route case, the mixture was placed in a furnace heated to 500°C followed by calcination at different temperatures for 2 h. In the conventional route cases, the mixtures were slowly heated to 800°C for 2 h. The obtained powders, product of the combustion reactions, were characterized by X-ray diffraction (XRD), laser scattering particle size analyzer and scanning electron microscopy (SEM). The results showed that the product (powder) obtained by direct reaction was the MgAl2O4 as the only crystalline phase formed with particle sizes of approximately 41 μm. Even so, small particles with sizes of about 30 nm were also observed according to measurements on SEM images.

Investigation on Structural, Optical and Morphological Properties of the SnSe Films with Function of Annealing Temperatures

2018 ◽  
Vol 24 (8) ◽  
pp. 5603-5607
Author(s):  
C. A. R. Maria Sahayaraj ◽  
A Mohan ◽  
R. Rathes Kannan ◽  
S Rajesh
Keyword(s):  
Morphological Properties ◽  
X Ray Diffraction ◽  
Orthorhombic Crystal ◽  
Sem Images ◽  
Orthorhombic Crystal Structure ◽  
Annealing Temperatures ◽  
Different Temperatures ◽  
Evaporation Technique ◽  
Crystalline Nature ◽  
The Impact

The work, studies on the impact of annealing on Tin Selenide thin films prepared by thermal evaporation technique. The films were annealed at different temperatures (150 °C–350 °C) inside the vacuum chamber under the pressure of 10−5 to 10−6 torr. The effects of annealing on the SnSe films were studied by various characterization techniques. The X-ray diffraction study reveals the as prepared SnSe films have orthorhombic crystal structure and annealing enhance the crystalline nature. The grain size is found to be 29 nm to 35 nm. The FE-SEM images observed that both uniform shaped grains of the annealing. The Selenium (Se) content has reduced after annealing due to re-evaporation of Se at higher annealing temperatures. The optical band gap values are found to be varying between 1.1 eV and 2.79 eV.

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