999 resultados para Productivity shock


Relevância:

20.00% 20.00%

Publicador:

Resumo:

In the 21st Century much of the world will experience untold wealth and prosperity that could not even be conceived only some three centuries before. However as with most, if not all, of the human civilisations, increases in prosperity have accumulated significant environmental impacts that threaten to result in environmentally induced economic decline. A key part of the world’s response to this challenge is to rapidly decarbonise economies around the world, with options to achieve 60-80 per cent improvements (i.e. in the order of Factor 5) in energy and water productivity now available and proven in every sector. Drawing upon the 2009 publication “Factor 5”, in this paper we discuss how to realise such large-scale improvements, involving complexity beyond technical and process innovation. We begin by considering the concept of greenhouse gas stabilisation trajectories that include reducing current greenhouse gas emissions to achieve a ‘peaking’ of global emissions, and subsequent ‘tailing’ of emissions to the desired endpoint in ‘decarbonising’ the economy. Temporal priorities given to peaking and tailing have significant implications for the mix of decarbonising solutions and the need for government and market assistance in causing them to be implemented, requiring careful consideration upfront. Within this context we refer to a number of examples of Factor 5 style opportunities for energy productivity and decarbonisation, and then discuss the need for critical economic contributions to take such success from examples to central mechanisms in decarbonizing the global economy.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This series of research vignettes is aimed at sharing current and interesting research findings from our team of international Entrepreneurship researchers. This vignette, written by Professor Beth Webster at Swinburne University of Technology, examines how innovation in small and medium size businesses affect their productivity.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

PURPOSE: This study investigated the significance of baseline cortisol levels and adrenal response to corticotropin in shocked patients after acute myocardial infarction (AMI). METHODS: A short corticotropin stimulation test was performed in 35 patients with cardiogenic shock after AMI by intravenously injecting of 250 μg of tetracosactrin (Synacthen). Blood samples were obtained at baseline (T0) before and at 30 (T30) and 60 (T60) minutes after the test to determine plasma total cortisol (TC) and free cortisol concentrations. The main outcome measure was in-hospital mortality and its association with T0 TC and maximum response to corticotropin (maximum difference [Δ max] in cortisol levels between T0 and the highest value between T30 and T60). RESULTS: The in-hospital mortality was 37%, and the median time to death was 4 days (interquartile range, 3-9 days). There was some evidence of an increased mortality in patients with T0 TC concentrations greater than 34 μg/dL (P=.07). Maximum difference by itself was not an independent predictor of death. Patients with a T0 TC 34 μg/dL or less and Δ max greater than 9 μg/dL appeared to have the most favorable survival (91%) when compared with the other 2 groups: T0 34 μg/dL or less and Δ max 9 μg/dL or less or T0 34 μg/dL or higher and Δ max greater than 9 μg/dL (75%; P=.8) and T0 greater than 34 μg/dL and Δ max 9 μg/dL or less (60%; P=.02). Corticosteroid therapy was associated with an increased mortality (P=.03). There was a strong correlation between plasma TC and free cortisol (r=0.85). CONCLUSIONS: A high baseline plasma TC was associated with a trend toward increased mortality in patients with cardiogenic shock post-AMI. Patients with lower baseline TC, but with an inducible adrenal response, appeared to have a survival benefit. A prognostic system based on basal TC and Δ max similar to that described in septic shock appears feasible in this cohort. Corticosteroid therapy was associated with adverse outcomes. These findings require further validation in larger studies.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

With the use of tensor analysis and the method of singular surfaces, an infinite system of equations can be derived to study the propagation of curved shocks of arbitrary strength in gas dynamics. The first three of these have been explicitly given here. This system is further reduced to one involving scalars only. The choice of dependent variables in the infinite system is quite important, it leads to coefficients free from singularities for all values of the shock strength.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Commercially available mullite (3Al(2)O(3). 2SiO(2)) powders containing oxides of calcium and iron as impurities, have been made suitable for plasma spraying by using an organic binder. Stainless steel substrates covered with Ni-22Cr-10Al-1.0Y bond coat were spray coated with mullite, The 425 mu m thick coatings were subjected to thermal shock cycling under burner rig conditions between 1000 and 1200 degrees C and less than 200 degrees C with holding times of 1, 5, and 30 min. While the coatings withstood as high as 1000 shock cycles without failure between 1000 and 200 degrees C, spallation occurred early at 120 cycles when shocked from 1200 degrees C, The coatings appeared to go through a process of self erosion at high temperatures resulting in loss of material. Also observed were changes attributable to melting of the silicate grains, which smooth down the surface. Oxidation of the bond coat did not appear to influence the failure, These observations were supported by detailed scanning electron microscopy and quantitative chemical composition analysis, differential thermal analysis, and surface roughness measurements.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Japanese encephalitis virus (JEV) envelope (E) protein has been shown to play a critical role in attachment to cells. However, the receptor interacting with envelope protein has not been conclusively identified. Using mouse neuroblastoma (Neuro2a) cells and purified JEV-E protein in `Virus Overlay Protein Binding Assay' followed by MALDI-TOF analysis, we identified `heat shock protein 70' (Hsp70) as a possible receptor for JEV. Indirect immunofluorescence and flow-cytometry analysis demonstrated localization of Hsp70 on Neuro2a cell surface. Co-immunoprecipitation followed by Western blot analysis reconfirmed the interaction between Hsp70 and JEV-E protein. Further, anti-Hsp70 polyclonal-antibodies were able to block JEV entry into Neuro2a cells. Additionally, using the bioinformatic tool - FTDOCK, clocking between the proteins was performed. Amongst six interacting structural poses studied one pose involving RGD motif on JEV-E and leucine(539) on Hsp70 displayed stable interaction. These observations indicate that Hsp70 serves as putative receptor for JEV in Neuro2A cells.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Tässä työssä tutkitaan englannin kielen substantiivijohtimien -ness ja -ity produktiivisuutta 1600-luvulla kirjoitetuissa kirjeissä. Näitä lähes synonyymisiä johtimia käytetään yleensä merkitykseltään abstraktien substantiivien muodostamiseen adjektiiveista (esim. productive 'produktiivinen' > productiveness tai productivity 'produktiivisuus'). Johtimista -ity on lainautunut englantiin ranskasta ja myöhemmin myös latinasta; se on sekä fonologialtaan että semantiikaltaan läpinäkymättömämpi kuin kotoperäinen -ness. Lisäksi -ity-johdinta on käytetty enimmäkseen formaaleissa tilanteissa ja tieteellisissä teksteissä, kun taas -ness on ollut yleiskäyttöisempi. Tutkielman lähestymistapa on sosiolingvistinen: oletetaan, että johtimien produktiivisuus (eli valmius muodostaa uusia johdoksia) voi vaihdella eri sosiaaliryhmissä. Sosiolingvistiikkaa ei ole aiemmin juurikaan sovellettu produktiivisuuden tutkimiseen. Tutkimusaineistona on Helsingin yliopiston VARIENG-tutkimusyksikön laatima Corpus of Early English Correspondence, varhaisista englanninkielisistä kirjeistä koostuva korpus eli elektroninen tekstikokoelma, joka on suunniteltu historiallisen sosiolingvistiikan tarpeisiin. Korpuksen 1600-luvun kirjeitten yhteenlaskettu pituus on noin 1,4 miljoonaa sanaa, ja ne on kirjoitettu vuosina 1600-1681. Tutkielman tärkeimpänä produktiivisuusmittarina käytetään johtimien avulla muodostettujen eri sanojen eli tyyppien lukumäärää. Hypoteesina on, että -ity-tyyppien määrä on keskimääräistä pienempi huonosti koulutettujen sosiaaliryhmien kirjeissä. Näitä olivat 1600-luvulla naiset sekä alhaisimmat yhteiskuntaryhmät, kuten talonpojat ja käsityöläiset. Johtimen -ness tyyppimäärissä ei odoteta esiintyvän sosiolingvististä variaatiota. Tutkielmassa käsitellään myös tyyppimäärien vertailuun liittyviä metodologisia ongelmia. Koska vaikkapa naisilta ja miehiltä on eri määrä dataa, ei heidän tyyppimääriään voida suoraan verrata keskenään. Esimerkiksi tyyppimäärien normalisointi tuhatta sanaa kohti ei myöskään ole mahdollista, koska tyyppien lukumäärä ei kasva lineaarisesti korpuksen kasvaessa. Tutkielmassa esitetään kielitieteessä harvoin käytetty tilastotieteellinen menetelmä, jonka avulla korpuksen eri osista saatuja tyyppimääriä voidaan verrata koko korpukseen ja testata, ovatko ne tilastollisesti merkittävän pieniä tai suuria. Toisin kuin monet yleisemmät menetelmät, tämä tyyppikertymiin ja permutaatiotesteihin perustuva metodi ei vaadi yksinkertaistavien oletuksien tekemistä. Tutkimustulokset vahvistavat hypoteesin oikeaksi: naisten -ity-tyyppien lukumäärä on tilastollisesti merkittävän alhainen, kun taas -ness-tyyppien määrissä ei ole tilastollisesti merkittäviä eroja. Alhaisimpien yhteiskuntaryhmien osalta tuloksia ei saada, koska niiltä on korpuksessa liian vähän dataa. Analyysissä paljastuu myös yllättävä eroavaisuus: korpuksen ajallisesti ensimmäisessä puoliskossa (1600-1639) on merkittävän vähän -ity-tyyppejä. Tämä voidaan tulkita kielelliseksi muutokseksi: -ity-johtimen produktiivisuus kasvaa kirjeissä 1600-luvun aikana. Saattaa olla, että johtimen produktiivisuus on ensin kasvanut formaalimmissa tekstilajeissa, joista lisääntynyt käyttö on sitten levinnyt myös kirjeisiin, ehkäpä 1640-luvun sisällissodan synnyttämien kontaktiverkostojen siivittämänä. Tuloksien perusteella voidaan sanoa, että sosiolingvistinen vaihtelu on merkittävä tekijä ainakin joittenkin johtimien produktiivisuudessa, joten vaihtelua on syytä tutkia enemmänkin. Tutkimuksessa käytetty metodi mahdollistaa osakorpuksien tyyppimäärien luotettavan vertailun melko pienissäkin korpuksissa, joten se soveltuu hyvin niin historialliseen kielitieteeseen kuin sosiolingvistiikkaankin.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Continuous cultivation and cereal cropping of southern Queensland soils previously supporting native vegetation have resulted in reduced soil nitrogen supply, and consequently decreased cereal grain yields and low grain protein. To enhance yields and protein concentrations of wheat, management practices involving N fertiliser application, with no-tillage and stubble retention, grain legumes, and legume leys were evaluated from 1987 to 1998 on a fertility-depleted Vertosol at Warra, southern Queensland. The objective of this study was to examine the effect of lucerne in a 2-year lucerne–wheat rotation for its nitrogen and disease-break benefits to subsequent grain yield and protein content of wheat as compared with continuous wheat cropping. Dry matter production and nitrogen yields of lucerne were closely correlated with the total rainfall for October–September as well as March–September rainfall. Each 100 mm of total rainfall resulted in 0.97 t/ha of dry matter and 26 kg/ha of nitrogen yield. For the March–September rainfall, the corresponding values were 1.26 t/ha of dry matter and 36 kg/ha of nitrogen yield. The latter values were 10% lower than those produced by annual medics during a similar period. Compared with wheat–wheat cropping, significant increases in total soil nitrogen were observed only in 1990, 1992 and 1994 but increases in soil mineralisable nitrogen were observed in most years following lucerne. Similarly, pre-plant nitrate nitrogen in the soil profile following lucerne was higher by 74 kg/ha (9–167 kg N/ha) than that of wheat–wheat without N fertiliser in all years except 1996. Consequently, higher wheat grain protein (7 out of 9 seasons) and grain yield (4 out of 9 seasons) were produced compared with continuous wheat. There was significant depression in grain yield in 2 (1993 and 1995) out of 9 seasons attributed to soil moisture depletion and/or low growing season rainfall. Consequently, the overall responses in yield were lower than those of 50 kg/ha of fertiliser nitrogen applied to wheat–wheat crops, 2-year medic–wheat or chickpea–wheat rotation, although grain protein concentrations were higher following lucerne. The incidence and severity of the soilborne disease, common root rot of wheat caused by Bipolaris sorokiniana, was generally higher in lucerne–wheat than in continuous wheat with no nitrogen fertiliser applications, since its severity was significantly correlated with plant available water at sowing. No significant incidence of crown rot or root lesion nematode was observed. Thus, productivity, which was mainly due to nitrogen accretion in this experiment, can be maintained where short duration lucerne leys are grown in rotations with wheat.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Soil nitrogen (N) supply in the Vertosols of southern Queensland, Australia has steadily declined as a result of long-term cereal cropping without N fertiliser application or rotations with legumes. Nitrogen-fixing legumes such as lucerne may enhance soil N supply and therefore could be used in lucerne-wheat rotations. However, lucerne leys in this subtropical environment can create a soil moisture deficit, which may persist for a number of seasons. Therefore, we evaluated the effect of varying the duration of a lucerne ley (for up to 4 years) on soil N increase, N supply to wheat, soil water changes, wheat yields and wheat protein on a fertility-depleted Vertosol in a field experiment between 1989 and 1996 at Warra (26degrees 47'S, 150degrees53'E), southern Queensland. The experiment consisted of a wheat-wheat rotation, and 8 treatments of lucerne leys starting in 1989 (phase 1) or 1990 (phase 2) for 1,2,3 or 4 years duration, followed by wheat cropping. Lucerne DM yield and N yield increased with increasing duration of lucerne leys. Soil N increased over time following 2 years of lucerne but there was no further significant increase after 3 or 4 years of lucerne ley. Soil nitrate concentrations increased significantly with all lucerne leys and moved progressively downward in the soil profile from 1992 to 1995. Soil water, especially at 0.9-1.2 m depth, remained significantly lower for the next 3 years after the termination of the 4 year lucerne ley than under continuous wheat. No significant increase in wheat yields was observed from 1992 to 1995, irrespective of the lucerne ley. However, wheat grain protein concentrations were significantly higher under lucerne-wheat than under wheat wheat rotations for 3-5 years. The lucerne yield and soil water and nitrate-N concentrations were satisfactorily simulated with the APSIM model. Although significant N accretion occurred in the soil following lucerne leys, in drier seasons, recharge of the drier soil profile following long duration lucerne occurred after 3 years. Consequently, 3- and 4-year lucerne-wheat rotations resulted in more variable wheat yields than wheat-wheat rotations in this region. The remaining challenge in using lucerne-wheat rotations is balancing the N accretion benefits with plant-available water deficits, which are most likely to occur in the highly variable rainfall conditions of this region.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Results from the humid tropics of Australia demonstrate that diverse plantations can achieve greater productivity than monocultures. We found that increases in both the observed species number and the effective species richness were significantly related to increased levels of productivity as measured by stand basal area or mean individual tree basal area. Four of five plantation species were more productive in mixtures with other species than in monocultures, offering on average, a 55% increase in mean tree basal area. A general linear model suggests that species richness had a significant effect on mean individual tree basal area when environmental variables were included in the model. As monoculture plantations are currently the preferred reforestation method throughout the tropics these results suggest that significant productivity and ecological gains could be made if multi-species plantations are more broadly pursued.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Detailed data on seagrass distribution, abundance, growth rates and community structure information were collected at Orman Reefs in March 2004 to estimate the above-ground productivity and carbon assimilated by seagrass meadows. Seagrass meadows were re-examined in November 2004 for comparison at the seasonal extremes of seagrass abundance. Ten seagrass species were identified in the meadows on Orman Reefs. Extensive seagrass coverage was found in March (18,700 ha) and November (21,600 ha), with seagrass covering the majority of the intertidal reef-top areas and a large proportion of the subtidal areas examined. There were marked differences in seagrass above-ground biomass, distribution and species composition between the two surveys. Major changes between March and November included a substantial decline in biomass for intertidal meadows and an expansion in area of subtidal meadows. Changes were most likely a result of greater tidal exposure of intertidal meadows prior to November leading to desiccation and temperature-related stress. The Orman Reef seagrass meadows had a total above-ground productivity of 259.8 t DW day-1 and estimated carbon assimilation of 89.4 t C day-1 in March. The majority of this production came from the intertidal meadows which accounted for 81% of the total production. Intra-annual changes in seagrass species composition, shoot density and size of meadows measured in this study were likely to have a strong influence on the total above-ground production during the year. The net estimated above-ground productivity of Orman Reefs meadows in March 2004 (1.19 g C m-2 day-1) was high compared with other tropical seagrass areas that have been studied and also higher than many other marine, estuarine and terrestrial plant communities.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Residue retention is an important issue in evaluating the sustainability of production forestry. However, its long-term impacts have not been studied extensively, especially in sub-tropical environments. This study investigated the long-term impact of harvest residue retention on tree nutrition, growth and productivity of a F1 hybrid (Pinus elliottii var. elliottii × Pinus caribaea var. hondurensis) exotic pine plantation in sub-tropical Australia, under three harvest residue management regimes: (1) residue removal, RR0; (2) single residue retention, RR1; and (3) double residue retention, RR2. The experiment, established in 1996, is a randomised complete block design with 4 replicates. Tree growth measurements in this study were carried out at ages 2, 4, 6, 8 and 10 years, while foliar nutrient analyses were carried out at ages 2, 4, 6 and 10 years. Litter production and litter nitrogen (N) and phosphorus (P) measurements were carried out quarterly over a 15-month period between ages 9 and 10 years. Results showed that total tree growth was still greater in residue-retained treatments compared to the RR0 treatment. However, mean annual increments of diameter at breast height (MAID) and basal area (MAIB) declined significantly after age 4 years to about 68-78% at age 10 years. Declining foliar N and P concentrations accounted for 62% (p < 0.05) of the variation of growth rates after age 4 years, and foliar N and P concentrations were either marginal or below critical concentrations. In addition, litter production, and litter N and P contents were not significantly different among the treatments. This study suggests that the impact of residue retention on tree nutrition and growth rates might be limited over a longer period, and that the integration of alternative forest management practices is necessary to sustain the benefits of harvest residues until the end of the rotation.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Knowledge of drag force is an important design parameter in aerodynamics. Measurement of aerodynamic forces at hypersonic speed is a challenge and usually ground test facilities like shock tunnels are used to carry out such tests. Accelerometer based force balances are commonly employed for measuring aerodynamic drag around bodies in hypersonic shock tunnels. In this study, we present an analysis of the effect of model material on the performance of an accelerometer balance used for measurement of drag in impulse facilities. From the experimental studies performed on models constructed out of Bakelite HYLEM and Aluminum, it is clear that the rigid body assumption does not hold good during the short testing duration available in shock tunnels. This is notwithstanding the fact that the rubber bush used for supporting the model allows unconstrained motion of the model during the short testing time available in the shock tunnel. The vibrations induced in the model on impact loading in the shock tunnel are damped out in metallic model, resulting in a smooth acceleration signal, while the signal become noisy and non-linear when we use non-isotropic materials like Bakelite HYLEM. This also implies that careful analysis and proper data reduction methodologies are necessary for measuring aerodynamic drag for non-metallic models in shock tunnels. The results from the drag measurements carried out using a 60 degrees half angle blunt cone is given in the present analysis.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This thesis analyses the implications for football cultures of the profound socio-economic changes that Brazil has experienced in the last decade. It explores two major impacts: the economic boom of the domestic football sector, and the large-scale adoption of new technologies in fans' activities. The study identified a new phase of football culture in Brazil, characterised by the domination of market logics and intense commercialisation. The empirical findings also showed that new technologies are changing how supporters coordinate activities that challenge the gentrification of the game.