20 resultados para Brutus, Marcus Junius, 85? B.C.-42 B.C.

em Deakin Research Online - Australia


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Reforestation has large potential for mitigating climate change through carbon sequestration. Native mixed-species plantings have a higher potential to reverse biodiversity loss than do plantations of production species, but there are few data on their capacity to store carbon. A chronosequence (5-45 years) of 36 native mixed-species plantings, paired with adjacent pastures, was measured to investigate changes to stocks among C pools following reforestation of agricultural land in the medium rainfall zone (400-800 mm yr(-1) ) of temperate Australia. These mixed-species plantings accumulated 3.09 ± 0.85 t C ha(-1)  yr(-1) in aboveground biomass and 0.18 ± 0.05 t C ha(-1)  yr(-1) in plant litter, reaching amounts comparable to those measured in remnant woodlands by 20 years and 36 years after reforestation respectively. Soil C was slower to increase, with increases seen only after 45 years, at which time stocks had not reached the amounts found in remnant woodlands. The amount of trees (tree density and basal area) was positively associated with the accumulation of carbon in aboveground biomass and litter. In contrast, changes to soil C were most strongly related to the productivity of the location (a forest productivity index and soil N content in the adjacent pasture). At 30 years, native mixed-species plantings had increased the stability of soil C stocks, with higher amounts of recalcitrant C and higher C : N ratios than their adjacent pastures. Reforestation with native mixed-species plantings did not significantly change the availability of macronutrients (N, K, Ca, Mg, P, and S) or micronutrients (Fe, B, Mn, Zn, and Cu), content of plant toxins (Al, Si), acidity, or salinity (Na, electrical conductivity) in the soil. In this medium rainfall area, native mixed-species plantings provided comparable rates of C sequestration to local production species, with the probable additional benefit of providing better quality habitat for native biota. These results demonstrate that reforestation using native mixed-species plantings is an effective alternative for carbon sequestration to standard monocultures of production species in medium rainfall areas of temperate continental climates, where they can effectively store C, convert C into stable pools and provide greater benefits for biodiversity.

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Results of permittivity measurements, electromagnetic interference shielding effectiveness, and heat generation due to microwave absorption in conducting polymer coated textiles are reported and discussed. The intrinsically conducting polymer, polypyrrole, doped with anthraquinone-2-sulfonic acid (AQSA) or para-toluene-2-sulfonic acid (pTSA) was applied on textile substrates and the resulting materials were investigated in the frequency range 1–18 GHz. The 0.54 mm thick conducting textile/polypyrrole composites absorbed up to 49.5% of the incident 30–35 W microwave radiation. A thermography station was used to monitor the temperature of these composites during the irradiation process, where absorption was confirmed via visible heat losses. Samples with lower conductivity showed larger temperature increases caused by microwave absorption compared to samples with higher conductivity. A sample with an average sheet resistivity of 150 Ω/sq. showed a maximum temperature increase of 5.27 °C, whilst a sample with a lower resistivity (105 Ω/sq.) rose by 3.85 °C.


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Solar-aided power generation (SAPG) is capable of integrating solar thermal energy into a conventional thermal power plant, at multi-points and multi-levels, to replace parts of steam extractions in the regenerative Rankine cycle. The integration assists the power plant to reduce coal (gas) consumption and pollution emission or to increase power output. The overall efficiencies of the SAPG plants with different solar replacements of extraction steam have been studied in this paper. The results indicate that the solar thermal to electricity conversion efficiencies of the SAPG system are higher than those of a solar-alone power plant with the same temperature level of solar input. The efficiency with solar input at 330 °C can be as high as 45% theoretically in a SAPG plant. Even the low-temperature solar heat at about 85 °C can be used in the SAPG system to heat the lower temperature feedwater, and the solar to electricity efficiency is nearly 10%. However, the low-temperature heat resource is very hard to be used for power generation in other types of solar power plants. Therefore, the SAPG plant is one of the most efficient ways for solar thermal power generation.

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Measurements of the glass transition temperature (Tg) and free volume behaviour of poly(acrylonitrile) (PAN) and PAN/lithium triflate (LiTf), with varying salt composition from 10 to 66 wt% LiTf, were made by positron annihilation lifetime spectroscopy (PALS). Addition of salt from 10 to 45 wt% LiTf resulted in an increase in the mean free volume cavity size at room temperature (r.t.) as measured by the orthoPositronium (oPs) pickoff lifetime, τ3, with little change in relative concentration of free volume sites as measured by oPs pickoff intensity, I3. The region from 45 to 66 wt% salt displayed no variation in relative free volume cavity size and concentration. This salt concentration range (45 wt%<[LiTf]<66 wt%) corresponds to a region of high ionic conductivity of order 10−5 to 10−6 S cm−1 at Tg as measured by PALS. A percolation phenomenon is postulated to describe conduction in this composition region. Salt addition was shown to lower the Tg as measured by PALS; Tg was 115°C for PAN and 85°C for PAN/66 wt% LiTf. The Tg and free volume behaviour of this polymer-in-salt electrolyte (PISE) was compared to a poly(ether urethane)/LiClO4 where the polymer is the major component, i.e. traditional solid polymer electrolyte (SPE). In contrast to the PISE, the Tg of the SPE was shown to increase with increasing salt concentration from 5.3 to 15.9 wt%. The relative free volume cavity size and concentration at r.t. were shown to decrease with increasing salt concentration. Ionic conductivity in this SPE was of order 10−5 S cm−1 at r.t., which is over 60°C above Tg, 108 S cm−1 at 25°C above Tg, and conductivity was not measurable at Tg.

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The ionic liquid (IL) N-methyl-N-butylmorpholinium bis(fluorosulfonyl)imide (C4mmor FSI) is examined from physical and electrochemical perspectives. Pulsed field gradient NMR spectroscopy shows that ion diffusivities are low compared with similar, non-ethereal ILs. Ionicity values indicate that above room temperature, less than 50% of ions contribute to conductivity.

Lithium cycling in symmetrical cells using a C4mmor FSI-based electrolyte is best demonstrated at elevated temperatures. Specific capacities of 130 mAh g−1 are achieved in a Li−LiFePO4 battery at 85 °C. FT-IR spectroscopic investigations of lithium electrodes suggest the presence of alkoxide species in the solid electrolyte interphase (SEI), implying a ring-opening reaction of C4mmor with lithium metal. In contrast, the SEI derived from N-methyl-N-propylpiperidinium FSI lacks the alkoxide signature but shows signs of alkyl unsaturation, and the activation energy for Li+ transport through this SEI is slightly lower than that for the C4mmor-derived SEI. Our detailed findings give insight into the capabilities and limitations of rechargeable lithium metal batteries utilizing a C4mmor FSI electrolyte.

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The stability of encapsulated planar-structured CH3NH3PbI3 (MAPbI3) perovskite solar cells (PSCs) was investigated under various simulated environmental conditions. The tests were performed under approximately one sun (100 mW cm-2) illumination, varying temperature (up to 85 °C cell temperature) and humidity (up to 80%). The application of advanced sealing techniques improved the device stability, but all devices showed significant degradation after prolonged aging at high temperature and humidity. The degradation mechanism was studied by post-mortem analysis of the disassembled cells using SEM and XRD. This revealed that the degradation was mainly due to the decomposition of MAPbI3, as a result of reaction with H2O, and the subsequent reaction of hydroiodic acid, formed during MAPbI3 decomposition, with the silver back contact electrode layer.

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This study investigated the effect of water deprivation on the expression of C-type natriuretic peptide (CNP) and natriuretic peptide receptor B (NPR-B) mRNA, and the ability of NPR-B to generate cGMP in the Spinifex Hopping mouse, Notomys alexis. This rodent is a native of central and western Australia that is well adapted to survive in arid environments. Initially, CNP and NPR-B cDNAs (partial for NPR-B) were cloned and sequenced, and were shown to have high homology with those of rat and mouse. RT-PCR analysis showed CNP mRNA expression in the kidney, proximal and distal colon and small intestine, whilst NPR-B mRNA expression was found in the kidney, proximal and distal colon and the atria. Using a semi-quantitative multiplex PCR technique, the expression of renal CNP and NPR-B mRNA was determined in 7- and 14-day water-deprived hopping mice, in parallel with control hopping mice (access to water). Water deprivation significantly decreased the relative levels of CNP and NPR-B mRNA expression in both the 7- and 14-day water-deprived hopping mice, when compared to control hopping mice. In contrast, the ability of CNP to stimulate cGMP production was significantly increased after 14 days of water deprivation. This study shows that alterations in the renal CNP/NPR-B system may be an important physiological adjustment when water is scarce.

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Tumor necrosis factor (TNF) plays a role in the pathogenesis of chronic hepatitis B (CHB) and chronic hepatitis C (CHC). The difference in the cytokine responses between hepatitis B virus (HBV) and hepatitis C virus (HCV) infections may have implications in the pathogenesis of these diseases. We performed a comparative study to examine the possible differences in the TNF-TNF receptor (TNFR) response between CHB and CHC. We studied the cytokine levels of 38 patients with CHB, 40 patients with CHC and 9 patients with dual hepatitis B and C, and compared them with the baseline levels of 12 healthy controls. The plasma levels of TNF-, interferon-, interleukin (IL)-2, IL-4, IL-10 and soluble TNFR-1 and 2 (sTNFR-1 and 2) were quantified by enzyme-linked immunosorbent assays. The expression of TNFR-1 and 2 in liver tissues was examined in 30 cases of CHB and 15 cases of CHC by semiquantitative reverse transcription polymerase chain reaction. The results showed that sTNFR-1 levels correlated with liver inflammation in all patients, whereas this correlation was not found with sTNFR-2 or other cytokines. Liver inflammation indicators were higher in HCV RNA+ than in HCV RNA– CHC. Most significantly, sTNFR-1 levels correlated with liver inflammation in CHB, but not in CHC. However, the expression of TNFR-1 and 2 in liver was similar between CHB and CHC. These findings suggest that the TNFR signal transduction pathway is modulated differently in HBV and HCV infection.

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BACKGROUND: The objective was to determine the contribution of transfusion in the past to the risk of current infection with hepatitis B or C among patients attending a large hospital for endoscopic procedures.
STUDY DESIGN AND METHODS: Blood samples had been tested for hepatitis markers by routine methods. Patients completed a comprehensive risk factor questionnaire and results were analyzed using computer software.
RESULTS: Twenty-seven percent of the 2120 participants in the study received transfusions in the past. There was no increase in prevalence of hepatitis B among those transfused. Compared with nontransfused participants, recipients of blood before the implementation of hepatitis C virus (HCV) screening in 1990 had a 4.6-fold increased risk of HCV infection, whereas those transfused with screened blood had a 3-fold increased risk. The difference between the odds ratios for patients before and after screening was not significant.
<b>CONCLUSIONS: Because screening has almost completely eliminated HCV from the blood supply, our finding of a continuing association of HCV infection with transfusion was unexpected. It implies that there are significant other nosocomial risks for hepatitis C transmission associated with the clinical situations where patients received blood. These should be actively investigated.

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This thesis is an ethnographic investigation of a Catholic Brothers school, Christian Brothers College (C.B.C.), in the provincial city of Newburyport, Australia* The study explores the traditions and historical purposes of education at the independent, religious school, and examines the manner in which these have changed or are changing. All names, including the name of the school and the city, have been altered to preserve anonymity. The opening section discusses the emergence of the theoretical problem of the dialectic of change and continuity in the ongoing activity of C.B.C. actors. This is followed by an argument that an understanding of such activity requires an ethnographic perspective. Such a perspective, however, must not overlook the organisational and structural constraints within which participants operate. Hence, a critical ethnography, which takes account of both the agency of human actors and the structures which influence their activity, is advocated as the most suitable approach for understanding continuity and change within a complex organisation in its social context. This argument is followed by an ethnographic account of Christian Brothers College, which focuses on the perceptions and activities of teachers and administrators, Individual chapters deal with the Christian Brothers Order and its educational mission at C.B.C.; the nature of religious education at the school; the administration of the school; approaches to control and discipline; the curriculum and evaluation of pupils; and the relationship between C.B.C. and the wider Newburyport community. The concluding section integrates an analysis of continuity and change at C.B.C. with a discussion of theoretical perspectives on reproduction and transformation. The thesis concludes that, although change has occurred in many ways, an institutionalised image of C.B.C. as 'Brothers’ school'persists and impedes the formation of more democratic authority relations, curriculum, and evaluation. The potential for such change, however, is seen most strongly in the ongoing reform of religious education.