137 resultados para Down-milling


Relevância:

20.00% 20.00%

Publicador:

Resumo:

This paper examines the relationship between the output levels in the mining sector and various non-mining sectors in an attempt to understand the role of the mining sector in Australia. The unobserved components time series model is used to estimate the effects of the output gap and the growth regime in the mining sector on the output level of each of several non-mining sectors. Overall, the estimates obtained do not suggest an overwhelmingly positive effect running from the mining sector to other production and services sectors, implying that the trickle-down effect of the mining boom may be a myth.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Immobility plus preexisting chronic disease or acute trauma can activate the coagulation system, thus increasing the risk for thromboembolic events. The effects of long-term bed-rest immobility and microgravity on the coagulation system of healthy persons (e.g., during crewed Mars missions) have not yet been studied. The main objective of the second Berlin BedRest Study (BBR2-2) "Coagulation Part" was to investigate adaptations of the hemostatic system during long-term bed rest (60 days) under simulated microgravity (6° head-down-tilt [6°HDT]) and after mobilization in three different volunteer groups (randomly assigned to CTR= inactive control group; RE= resistive exercise only group; and RVE= resistive exercise with whole-body vibration group). In 24 males (aged 21-45 years), before, during, and after long-term bed rest, key parameters of coagulation were measured from venous blood samples: D-dimer (DD), thrombin-antithrombin III complex (TAT), and prothrombin fragment F1 + 2 (PT-F1 + 2). Additionally, modified rotational thrombelastometry (ROTEM (®) ) analysis was performed. Times of exploratory analyses were as follows: baseline data collection 2 days before bed rest (BDC-2); eight different days of 6°HDT bed rest (HDT1-HDT60), and two different days after reambulation (R + 3 and R + 6). We found significant changes in DD, TAT, and PT-F1 + 2 over the total time course, but no consistent effect of physical interventions (RE, RVE) on these parameters. Notably, no parameter reached levels indicative of intravascular thrombin formation. All ROTEM® parameters remained within the normal range and no pathological traces were found. Sixty days of 6°HDT bed rest are not associated with pronounced activation of the coagulation system indicative of intravascular thrombus formation in healthy volunteers independent of the training type during the bed rest.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Silk fibroin has been widely employed in various forms as biomaterials for biomedical applications due to its superb biocompatibility and tunable degradation and mechanical properties. Herein, silk fibroin microparticles of non-mulberry silkworm species (Antheraea assamensis, Antheraea mylitta and Philosamia ricini) were fabricated via a top-down approach using a combination of wet-milling and spray drying techniques. Microparticles of mulberry silkworm (Bombyx mori) were also utilized for comparative studies. The fabricated microparticles were physico-chemically characterized for size, stability, morphology, chemical composition and thermal properties. The silk fibroin microparticles of all species were porous (∼5μm in size) and showed nearly spherical morphology with rough surface as revealed from dynamic light scattering and microscopic studies. Non-mulberry silk microparticles maintained the typical silk-II structure with β-sheet secondary conformation with higher thermal stability. Additionally, non-mulberry silk fibroin microparticles supported enhanced cell adhesion, spreading and viability of mouse fibroblasts than mulberry silk fibroin microparticles (p<0.001) as evidenced from fluorescence microscopy and cytotoxicity studies. Furthermore, in vitro drug release from the microparticles showed a significantly sustained release over 3 weeks. Taken together, this study demonstrates promising attributes of non-mulberry silk fibroin microparticles as a potential drug delivery vehicle/micro carrier for diverse biomedical applications.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The imprisonment rate in Australia is at unprecedented high levels, both interms of actual prisoner numbers and the rate at which it is increasing. Forthe first time in recorded history the incarceration rate in Australia has morethan doubled in less than 25 years. Prison is the harshest form ofpunishment in our system of justice and imposes considerable hardship onoffenders. It also comes at a considerable financial cost to the community.Accordingly, the surge in prisoner numbers is a significant macro social,economic and legal development. The increase did not occur pursuant to anoverarching strategic plan and is an area that is under-researched. Theprison population increase has arisen as a result of a ‘tough on crime’approach that continues without any sign of abatement. The use ofimprisonment should only be increased if there is a demonstrable benefit tothe community. This article examines whether there is a sound rationalebehind the rising trend in prison numbers. The increasing incarceration ratehas coincided with a significant reduction in the crime rate. A causalconnection between the two events (increased prisoner numbers andreduced crime) could constitute a powerful argument in favour of the surgein prison numbers. However, an examination of the empirical data inAustralia fails to demonstrate even a tenable link between these events. Wealso conclude that at the theoretical level there is no rationale for theincreased use of imprisonment. If the imprisonment rate continues to rise,there is a risk of a prison and financial crisis similar to that currently beingexperienced in the United States, which has resulted in an extremecounter-reaction in the form of a retrospective reduction of some prison terms.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

We reconstructed the nutrient source for egg synthesis by sampling Black-headed Gull (Larus ridibundus) eggs for yolk, analyzing their carbon stable isotope ratio, and comparing that to hatchling down. Most of the variation in carbon stable isotope ratio was explained by differences between nests, the within-nest variation being explained by laying order. These data indicate significant differences in diet choice between individual females and changes in food choice or body-store dynamics during egg laying. Among-egg variation in the carbon stable isotope ratios of the yolk were closely reflected in the hatchling down, on average down being enriched by 3.1‰ δ13C relative to yolk. Our findings support the contention that pre-laying female diets can be evaluated from hatchling down.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

 This study investigated whether IQ, language, theory of mind, emotion recognition, social skills and a behavioural marker of early neurodegeneration contributed to the externalising and internalising behaviour problems of children and adolescents with Down syndrome. Pragmatic language, social skills and neurodegeneration variables were significantly related to behaviour problems.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The influence of milling time on the powder packing characteristics and compressive mechanical properties of a biomedical Ti-10Nb-3Mo alloy (wt.%) was investigated. Ball milling was performed on elemental metal powders at different milling times of 0 (blended), 2, 4, 6, 8, and 10 h. This article demonstrates that despite the beneficial effects of ball milling technique in the mechanical alloying of the Ti-based alloy, the ball-milled powders synthesized at longer milling times can adversely affect the packing density and significantly diminish the compressive mechanical properties of the sintered powders. Crown

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In this study a gradient grain structure was produced by processing rod billets through three roll planetary milling (also known as PSW process). This kind of gradient structure is reported to provide an excellent combination of strength and ductility owing to an ultrafine-grained surface layer and a coarse-grained interior of the billet. Specifically, copper rod samples were subjected to up to six passes of PSW at room temperature. To study the evolution of the microstructure during the deformation, microhardness measurements and Electron Backscatter Diffraction (EBSD) analysis were performed after one, three and six passes. Additionally, the distributions of the equivalent stress during PSW and the equivalent strain after processing were studied by finite element analysis using the commercial software QFORM. The results showed the efficacy of PSW as a means of imparting a gradient ultrafine-grained structure to copper rods. A good correlation between the simulated equivalent strain distribution and the measured microhardness distribution was demonstrated.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Fat accumulates in the bone marrow of lumbar vertebrae with bed rest. Exercise with or without whole body vibration may counter this effect. Our objectives were to measure 1) the vertebral fat fraction (VFF) of men subjected to bed rest who performed resistive exercises with (RVE, n = 7) or without whole body vibration(RE, n = 8) or no exercise (CTR, n = 9) using three MRI techniques; and 2) changes in peripheral blood counts. Twenty-four healthy men (age: 20-45 yr) underwent -6° head-down tilt (HDT) bed rest for 60 days. MRI was performed using three techniques (fat saturation, proton spectroscopy, and in and out of phase) to measure the fat fraction of L(3), L(4), and/or L(5) at baseline, mid-HDT, and end-HDT. Erythrocytes and leukocytes were counted at HDT days 19, 33, 47, 54, and 60. The mean absolute VFF was increased in the CTR group at mid-HDT and end-HDT (+3.9 ± 1.3 and +3.6 ± 1.2%, respectively, both P < 0.05). The RE group had a smaller VFF change than the CTR group at mid-HDT (-0.9 ± 1.2 vs. +3.9 ± 1.3%, P < 0.05). The RVE group had a smaller VFF change than the CTR group at end-HDT (-2.6 ± 1.9 vs. +3.5 ± 1.2%, P < 0.05). Erythrocyte counts were increased in all groups at HDT day 19 and HDT day 33 and in the RE group at HDT day 54 (all P < 0.05). Bed rest for 60 days at -6° HDT increased lumbar VFF in men beyond natural involution. RVE and RE regimens effectively prevented VFF accumulation. Higher erythrocyte counts were not altered by RVE or RE. Whole body vibration, along with RE administered to people with prolonged immobility, may prevent fat accumulation in their bone marrow.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This research will definitely give guidelines to industries associated with titanium slot machining.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The corrosion resistance and mechanical properties of nanocrystalline aluminium (Al) and Al-20. wt.%Cr alloys, synthesized by high-energy ball milling followed by spark plasma sintering, were investigated. Both alloys exhibited an excellent combination of corrosion resistance and compressive yield strength, which was attributed to the nanocrystalline structure, extended solubility, uniformly distributed fine particles, and homogenous microstructure induced by high-energy ball milling. This work demonstrates the possibilities of developing ultra-high strength Al alloys with excellent corrosion resistance, exploiting conventionally insoluble elements or alloying additions via suitable processing routes.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Marine microalgae present a renewable alternative source for sustainable production of omega-3 fatty acids, as compared to conventional sources such as krill oil and fish oil. In this study, we optimised a method for lipid extraction from marine thraustochytrids using a bead mill and enzymatic concentration of omega-3 fatty acids from the thraustochytrid oil. The optimised lipid extraction conditions were, bead size 0.4-0.6μm, 4500rpm, 4min of processing time at 5g biomass concentration. The maximum lipid yield (% dry weight basis) achieved at optimum conditions were 40.5% for Schizochytrium sp. S31 (ATCC) and 49.4% for Schizochytrium sp. DT3 (in-house isolate). DT3 oil contained 39.8% docosahexaenoic acid (DHA) as a percentage of lipid, a higher DHA percentage than S31. Partial hydrolysis of DT3 oil using Candida rugosa lipase was performed to enrich omega-3 polyunsaturated fatty acids (PUFAs) in the glyceride portion. Total omega-3 fatty acid content was increased to 88.7%.