The effectiveness of active screen method in ion nitriding grade 5 ELI titanium alloy

A titanium alloy for biomedical applications, Grade 5 ELI, was studied, which was subjected to the ion nitriding process in the temperature range of 530 – 590 °C and during 5 – 17 h, using two variants of sample arrangement in the glow discharge chamber. The first variant – the samples intended for nitriding were placed on the cathode, the second variant – the samples placed on the cathode were shielded with an active screen. In order to assess the effectiveness of nitriding, studies were carried out on the depth of nitrogen diffusion into the substrate of the studied titanium alloy, surface hardness tests, as well as observation of the obtained microstructures and phase composition tests – in order to assess the structure of the surface layers. It was found that using active screens increases the rate of nitrogen diffusion deep into the nitrided Grade 5 ELI titanium alloy, and thus increases the thickness of the obtained nitrided layers

The effectiveness of active screen method in ion nitriding grade 5 ELI titanium alloy

A titanium alloy for biomedical applications, Grade 5 ELI, was studied, which was subjected to the ion nitriding process in the temperature range of 530 – 590 °C and during 5 – 17 h, using two variants of sample arrangement in the glow discharge chamber. The first variant – the samples intended for nitriding were placed on the cathode, the second variant – the samples placed on the cathode were shielded with an active screen. In order to assess the effectiveness of nitriding, studies were carried out on the depth of nitrogen diffusion into the substrate of the studied titanium alloy, surface hardness tests, as well as observation of the obtained microstructures and phase composition tests – in order to assess the structure of the surface layers. It was found that using active screens increases the rate of nitrogen diffusion deep into the nitrided Grade 5 ELI titanium alloy, and thus increases the thickness of the obtained nitrided layers

The efficiency of ion nitriding of austenitic stainless steel 304 using the “active screen”

The study examined layers were formed on the outer surface of austenitic stainless steel 304 under glow discharge conditions in the low-temperature and short-term ion nitriding. The outer layers analyzed in the work produced in parallel in the classical process of cathode and a novel method of “active screen”, intensifying the process of nitriding

Nitrogen and phosphorus budgets for the central Great Barrier Reef Shelf

Shelf-scale budgets were developed for the nutrient elements nitrogen (N) and phosphorus (P) in the central Great Barrier Reef between Cape Tribulation (I 60 S} and Dunk Island (ca. 18°S). The intent was to quantify: I} stocks of nutrients (nitrogen (N). phosphorus (P) and silicon (Si}) naturally occurring in central Great Barrier Reef waters; 2) natural gradients and variability in water column nutrient concentrations; 3} natural fluxes of nutrients into and out of shelf waters for comparison with anthropogenic or anthropogenically affected nutrient sources

Biological and chemical oceanographic measurements in Far Northern Great Barrier Reef - February 1990

This report presents and sununarises the results of biological and chemical oceanographic sampling carried out in the far northern Great Barrier Reef during February 1990. The region sampled (ca. 11-13°S), lies adjacent to the eastern side of Cape York Peninsula, locations on which are under consideration for national park declaration, the construction of a rocket launching facility and silica sand mining. As little is known regarding the biological and chemical oceanography of the region, a reconnaissance survey was carried out to obtain baseline data on hydrographic, nutrient and sediment characteristics of shelf waters and sediments. It is expected that the data presented herein will form part of the environmental assessment for development in, and conservation of, the region and serve as a basis for designing more detailed and focused water quality surveys

Procjena učinkovitosti nekonvencionalnog nitriranja austenitnog čelika 316L

The 316L grade austenitic steel after glow discharge nitriding at a temperature of T=733 K for a duration of τ = 61,2 ks and four different variants of specimen arrangement in the glow-discharge chamber was investigated. In order to assess the effectiveness of nitriding process variants, the profile analysis examination of obtained surface layers, surface hardness tests and surface layer hardness profile examination, the analysis of surface layer structures and abrasive wear were performed. It has been found that an application of the booster screens causes depth increase of the nitrogen diffusion into the nitrided 316L austenitic steel and thus an increase of the obtained surface layers thickness.Istraživani su uzorci austenitnog čelika stupnja 316L sa 4 različita postupka u komori za nitriranje na temperaturi T=733 K u trajanju τ =61,2 ks. Za procjenu učinkovitosti varijanti nitriranja provedena je analiza profila površinskog sloja, njegove tvrdoće kao i tvrdoće profila, površinske strukture te abrazijsko trošenje. Ustanovljeni su uzroci pojačane podrške i povećanje dubine difuzije u površini austenitnog čelika 316L pri nitriranju, te povećanje debljine nitriranog površinskog sloja

Kratkotrajno niskotemperaturno nitriranje austenitnog čelika 316L

The AISI 316L austenitic steel after glow discharge nitriding at temperature of T = 673 K and duration of τ=14,4 ks, for two different variants of specimen arrangement in the glow-discharge chamber was investigated. In order to assess the effectiveness of nitriding process, the surface layers profile analysis examination, surface hardness and hardness profile examination, the analysis of surface layer structures and corrosion resistance tests were performed. It has been found that application of a booster screen effects in a nitrogen diffusion depth increment into the 316L austenitic steel surface, what results in the surface layer thickness escalation.Ispitani su uzorci od AISI 316L austenitni čelik tretirani na dva raziličita načina u komori za nitriranje nakon nitriranja na temperaturi T=673 K u trajanju τ=14,4 s. Kako bi procijenili efikasnost procesa nitriranja provedena je analiza profila površinskog sloja, ispitana je površinska tvrdoća kao i tvrdoća profila, te analiza strukture površinskog sloja i ispitivanje korozijske otpornosti. Pronađena je primjena efekta pojačane podrške u povećanju dubine difuzije kod nitriranja u površinu austenitnog čelika 316L, što rezultira povećanje debljine površinskog sloja

Spiny Softshell (Apalone spinifera) turtles exhibit scarring consistent with attempted lamprey bites

We captured 46 Spiny Softshells (Apalone spinifera) during a mark–recapture study on Lake Erie (2012–2015). Six (13%) exhibited circular scars consistent with the bites of small parasitic lampreys. Two species of parasitic lampreys occur in Lake Erie: the invasive Sea Lamprey (Petromyzon marinus) and the native Silver Lamprey (Ichthyostomyzon unicuspis). The scars showed only the marks of the putative teeth surrounding the suctorial mouth, preventing identification based on the position of the supraoral teeth and suggesting that lampreys are rapidly dislodged from the turtles. To our knowledge, this is the first evidence of lampreys biting freshwater turtles

Preliminary development and validation of a new endof-life patient-reported outcome measure assessing the ability of patients to finalise their affairs at the end of life

Introduction:The ability of patients to finalise their affairs at the end of life is an often neglected aspect of quality of life (QOL) measurement in palliative care effectiveness research despite compelling evidence of the high value patients place on this domain. Objective: This paper describes the preliminary development and evaluation of a new, single-item, end-of-life patientreported outcome measure (EOLPRO) designed to capture changes in the ability of patients to finalise their affairs at the end of life. Methods: Cognitive interviews with purposively sampled Australian palliative care patients (N = 9) were analysed thematically to explore content validity. Simultaneously, secondary analysis of data from a randomised controlled trial comparing ketamine and placebo for the management of cancer pain (N = 185) evaluated: construct validity; test-retest reliability; and responsiveness. Results:Preliminary findings suggest patients interpret the new measure consistently. The EOLPRO captures the ability to complete physical tasks and finalise practical matters although it is unclear whether emotional tasks or resolution of relationship issues are considered. Personal and financial affairs should be separated to allow for differences in ability for these two types of affairs. The significant correlation between performance status and EOLPRO scores (r = 0.41, p,<.01, n = 137) and expected relationships between EOLPRO and proximity to death and constipation demonstrated construct validity. Pre-and post-treatment EOLPRO scores moderately agreed (n = 14, k = 0.52 [95% CI 0.19, 0.84]) supporting reliability. The measure's apparent lack of sensitivity to discriminate between treatment responders and non-responders may be confounded. Conclusion:Based on the preliminary findings, the EOLPRO should be separated into 'personal' and 'financial' affairs with further testing suggested, particularly to verify coverage and responsiveness. Initial evaluation suggests that the single-item EOLPRO is a useful addition to QOL outcome measurement in palliative care effectiveness research because common palliative care specific QOL questionnaires do not include or explicitly capture this domain. © 2014 McCaffrey et al

Order and phase nucleation in nonequilibrium nanocomposite Fe-Pt thin films with perpendicular magnetic anisotropy

We report on the time evolution of mass transport upon annealing nonequilibrium Fe-Pt nanocomposite films, leading to nucleation of L1(0) chemically ordered phase. The nonequilibrium nanocomposite films were fabricated by applying Fe(+) ion implantation to epitaxial Pt films grown on (001) MgO substrates, yielding Fe nanoclusters embedded in a Pt matrix at a tailored penetration depth. Time-resolved x-ray diffraction studies were carried out using synchrotron radiation, allowing determination of the activation energy for nucleation of the FePt L1(0) phase within the segregated nanoclusters during annealing. The growth of the segregated L1(0) ordered phase was modeled using ideal grain-size law and found to be dominated by strain-driven surface nucleation. The activation energies were found to correlate with the nanocluster size. Magnetic characterization of selected annealed samples indicates perpendicular magnetic anisotropy with high coercive field coincident with high value of the chemical order parameter of the ordered phase within the magnetic nanoclusters