Digital Commons Network^™

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 …

Relationship Between Sodium And Potassium Intake And Blood Pressure In A Sample Of Overweight Adults, Rhoda Ndanuko, Linda C. Tapsell, Karen E. Charlton, Elizabeth Neale, Katrina M. O'Donnell, Marijka Batterham

Faculty of Science, Medicine and Health - Papers: part A

Objective: The aim of this study was to examine the relationship between sodium and potassium intakes and blood pressure (BP) in a clinical sample.

Methods: Secondary analysis of baseline data from 328 participants (mean age: 43.6 ± 8 y, mean body mass index [BMI]: 32.4 ± 4.2 kg/m², mean systolic BP [SBP]/diastolic BP [DBP]: 124.9 ± 14.5/73.3 ± 9.9 mm Hg) of the 12-mo HealthTrack randomized controlled weight loss trial was conducted. Resting BP and 24-h urine sodium and potassium were measured. Dietary intake was evaluated with 4-d food records and self-reported diet histories.

Results: Urinary sodium was …

Sodium And Potassium Urinary Excretion And Dietary Intake: A Cross-Sectional Analysis In Adolescents, Carla Goncalves, Sandra Abreu, Patricia Padrao, Olivia Pinho, Pedro Graca, Joao Breda, Rute Santos, Pedro Moreira

Faculty of Social Sciences - Papers (Archive)

Background: Hypertension is the leading cause for heart disease and stroke, for mortality and morbidity worldwide, and a high sodium-to-potassium intake ratio is considered a stronger risk factor for hypertension than sodium alone. Objective: This study aims to evaluate sodium and potassium urinary excretion, and assess the food sources of these nutrients in a sample of Portuguese adolescents. Design: A cross-sectional study with a sample of 250 Portuguese adolescents. Sodium and potassium excretion were measured by one 24-h urinary collection, and the coefficient of creatinine was used to validate completeness of urine collections. Dietary sources of sodium and potassium were …

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 …

Study Of The Relationship Between Infrared Stimulated Luminescence And Blue Light Stimulated Luminescence For Potassium-Feldspar From Sediments, Zhijun Gong, Bo Li, Sheng-Hua Li

Faculty of Science, Medicine and Health - Papers: part A

In luminescence measurements of potassium-feldspar (K-feldspar), both infrared (IR) and blue light (BL) can be used as stimulation sources. Component analysis suggests that the blue light stimulated luminescence (BLSL) measured at 60 °C from K-feldspar can be fitted using three components, namely fast, medium and slow. In order to explore the relationship between the origin of the infrared stimulated luminescence (IRSL) signal and the different components of the BLSL, five sets of experiments were conducted, namely post-IR BLSL (pIR-BLSL), post-BL IRSL (pBL-IRSL), pulse annealing tests, dose response and laboratory fading rate tests. It is observed that most of the IRSL …

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 …}

Association Between Blood Pressure And Sodium, Potassium And Calcium Excretion In South Africans, Karen E. Charlton, Krisela Steyn, Jabuliswe Zulu, Deborah Jonathan, Naomi Levitt, J H. Nel, D Veldman

Faculty of Science, Medicine and Health - Papers: part A

No abstract provided.