Digital Commons Network^™

The Effect Of Flinak Molten Salt Corrosion On The Hardness Of Hastelloy N, David Kok

Honors Program Projects

The desire to reduce pollution caused by electricity production has led to a call for the replacement of conventional fossil fuel power plants. In order to fulfill this goal, a large amount of new nuclear reactors is required, and this provides the opportunity to put new and innovative reactor designs into production. The Molten Salt Reactor (MSR) is one of the most promising concepts, but a suitable combination of molten salt and container material needs to be found to reduce the potential for corrosion before the concept can be put into production. FLiNaK molten salt and the nickel-based alloy Hastelloy …

Mechanical Properties Of Micro-Steel Fibre Reinforced Magnesium Potassium Phosphate Cement Composite, Hu Feng, M Neaz Sheikh, Muhammad N. S Hadi, Danying Gao, Jun Zhao

Faculty of Engineering and Information Sciences - Papers: Part B

This paper presents the mechanical properties of micro-steel fibre (MSF) reinforced magnesium potassium phosphate cement (MPPC) composites with multi-composite retarder. The compressive strength, flexural strength, flexural toughness and flexural ductility of the MSF reinforced MPPC composite (MSFRMC) were experimentally explored. The variables of the experiment included sand-cement mass ratio, water-cement mass ratio, curing time and fibre volume fraction. In addition, the effect of different types of cement on the mechanical properties of MSF reinforced composites was investigated. It was found that with the increase of water content in the MPPC paste, the average compressive strength, flexural strength and flexural toughness …

Self-Growth Of Centimeter-Scale Single Crystals By Normal Sintering Process In Modified Potassium Sodium Niobate Ceramics, Cheol-Woo Ahn, Ho-Yong Lee, Guifang Han, Shujun Zhang, Si-Young Choi, Jong-Jin Choi, Jong-Woo Kim, Woon-Ha Yoon, Joon-Hwan Choi, Dong-Soo Park, Byung-Dong Hahn, Jungho Ryu

Australian Institute for Innovative Materials - Papers

In this manuscript, an interesting phenomenon is reported. That is the self-growth of single crystals in Pb-free piezoelectric ceramics. These crystals are several centimeters in size. They are grown without any seed addition through a normal sintering process in modified potassium sodium niobate ceramics. It has been achieved by the composition designed to compensate the Na + loss which occurs during the liquid phase sintering. The composition of the crystals is (K0.4925 Na0.4925-x Ba0.015+x/2)Nb 0.995+x O3 [x is determined by the Na+ loss, due to Na2O volatilization]. These crystals have high piezoelectric voltage coefficients (g33, 131 10-3 Vm/N), indicating that …

Potassium-Uracil/Thymine Ring Cleavage Enhancement As Studied In Electron Transfer Experiments And Theoretical Calculations, D Almeida, M.-C. Bacchus-Montabonel, F Ferreira Da Silva, G Garcia, P Limao-Vieira

Faculty of Engineering and Information Sciences - Papers: Part A

We report experimental and theoretical studies on ring cleavage enhancement in collisions of potassium atoms with uracil/thymine in order to further increase the understanding of the complex mechanisms yielding such fragmentation pathways. In these electron transfer processes time-of-flight (TOF) negative ion mass spectra were obtained in the collision energy range 13.5 – 23.0 eV. We note that CNO– is the major ring breaking anion formed and its threshold formation is discussed within the collision energy range studied. Such decomposition process is supported by the first theoretical calculations in order to clarify how DNA/RNA pyrimidine bases fragmentation is enhanced in electron …

Dynamic Of Negative Ions In Potassium-D-Ribose Collisions, D Almeida, F Ferreira Da Silva, G Garcia, P Limao-Vieira

Faculty of Engineering and Information Sciences - Papers: Part A

We present negative ion formation from collisions of neutral potassium atoms with D-ribose (C5H10O5), the sugar unit in the DNA/RNA molecule. From the negative ion time-of-flight (TOF) mass spectra, OH− is the main fragment detected in the collision range 50–100 eV accounting on average for 50% of the total anion yield. Prominence is also given to the rich fragmentation pattern observed with special attention to O− (16 m/z) formation. These results are in sharp contrast to dissociative electron attachment experiments. The TOF mass spectra assignments show that these channels are also observed, albeit with a much lower relative intensity. Branching …

Direct Observation Of Local Potassium Variation And Its Correlation To Electronic Inhomogeneity In (Ba1-Xkx)Fe2as 2 Pnictide, Wai Kong Yeoh, Baptiste Gault, X.Y. Cui, C. Zhu, P Moody, L. Li, Rongkun Zheng, Wenxian Li, Xiaolin Wang, S. X. Dou, G.L Sun, C T Lin, S P. Ringer

Faculty of Engineering - Papers (Archive)

Local fluctuations in the distribution of dopant atoms are thought to cause the nanoscale electronic disorder or phase separation in pnictide superconductors. Atom probe tomography has enabled the first direct observations of dopant species clustering in a K-doped 122-phase pnictide. First-principles calculations suggest the coexistence of static magnetism and superconductivity on a lattice parameter length scale over a wide range of dopant concentrations. Our results provide evidence for a mixed scenario of phase coexistence and phase separation, depending on local dopant atom distributions.

Lead-Free Potassium Bismuth Titanate Thin Film With Complex Aurivillius Layer Structure, Zhenxiang Cheng, Xiaolin Wang, Hongyang Zhao, Hideo Kimura

Australian Institute for Innovative Materials - Papers

A ferroelectric thin film of Aurivillius phase K_0.5Bi_4.5Ti₄O₁₅ (KBT) with a complex bismuth layer-structure was fabricated using the pulsed laser deposition method. The thin film grown on Pt/Ti/SiO₂/ Si substrate shows a strong c-axis orientation, as revealed by x-ray diffraction results, and platelike growth of grains. A Pt/KBT/Pt capacitor shows a maximum polarization of about 20 µC/cm². In addition, the capacitor also shows good fatigue resistance, with a decrease of 14.5% in the remanent polarization after 10⁷ switching cycles. This Aurivillius phase with four layers of TiO_{6 …}

Analysis Of An Ion‐Selective Electrode Based Methodology For Integrated On‐The‐Go Mapping Of Soil Ph, Potassium, And Nitrate Contents, B. Sethuramasamyraja, V. I. Adamchuk, D. B. Marx, A. Dobermann, G. E. Meyer, D. D. Jones

Department of Biological Systems Engineering: Papers and Publications

Knowledge of the spatial variation of soil attributes is critical for precision agriculture. On‐the‐go soil sensors have been able to provide relatively high mapping density while assessing this variation. A new ion‐selective electrode (ISE) based approach was developed and tested for simultaneous mapping of soil pH, residual nitrate (NO3 -), and soluble potassium (K+) contents. In this article, results of laboratory experiments investigating the effects of key measurement factors on ISE performance are presented. In addition to four different soils, these factors included: soil/water ratio (SWR), quality of water used for electrode rinsing (QWR) and for …

Distribution Pattern Variability Of Granular Vrt Applicators, John P. Fulton, Scott A. Shearer, Stephen F. Higgins, Dennis Wayne Hancock, Timothy S. Stombaugh

Biosystems and Agricultural Engineering Faculty Publications

Granular applicators equipped with variable-rate technology (VRT) have gained popularity in recent years as a result of increased interest in variable-rate application. The purpose of this investigation was to characterize distribution patterns at varying rates for different granular applicators. Uniform-rate (UR) tests were conducted to assess the accuracy of variable-rate application from four granular applicators: two spinner-disc spreaders (A and B), and two pneumatic applicators (C and D). Pattern results indicated a consistent triangular pattern for spinner spreader B and consistent patterns for the pneumatic applicators (C and D). However, applicator D produced pattern variations at the center and right …

Rate Response Assessment From Various Granular Vrt Applicators, John P. Fulton, Scott A. Shearer, Stephen F. Higgins, Matthew J. Darr, Timothy S. Stombaugh

Biosystems and Agricultural Engineering Faculty Publications

Variable-rate technology (VRT) adds complexity to application equipment, thereby confounding the assessment of applicator performance. The intent of this investigation was to assess the rate response of various VRT granular applicators: two spinner spreaders (A and B), and two pneumatic applicators (C and D). Variable-rate (VR) tests were conducted to quantify the rate response characteristics (delay and transition times) for the applicators. A sigmoidal function was used to model the rate response for five of the six tests. Applicator A exhibited a linear response during decreasing rate changes. Results indicated that only applicator B demonstrated consistent delay and transition times, …

Leases For Other Minerals: Recent Developments, Thomas F. Cope

Public Lands Mineral Leasing: Issues and Directions (Summer Conference, June 10-11)

14 pages.

Contains references.

Dependence Of Defibrillation Threshold Upon Extracellular/Intracellular K+ Concentrations, Charles F. Babbs, S J. Whistler, G Yim, L A. Geddes

Weldon School of Biomedical Engineering Faculty Publications

The effect of increasing extracellular potassium concentration (K_o) upon electrical ventricular defibrillation threshold was investigated in pentobarbital anesthetized dogs treated with intravenous potassium chloride. Defibrillation threshold fell during potassium intoxication. The percent decrease in defibrillation threshold was linearly related to the logarithm of K_o and to the potassium equilibrium potential, E_K, calculated from measured extracellular and intracellular potassium concentrations of ventricular muscle. In dogs supported by left ventricular bypass in order to maintain the circulation during potassium intoxication, the values of K_o and E_K required for spontaneous, K⁺ induced defibrillation (electrical defibrillation …