1,766 research outputs found
Estimating the cost of a new technology intensive automotive product: A case study approach.
Estimating cost of new technology intensive products is very ad hoc within the
automotive industry. There is a need to develop a systematic approach to the
cost estimating, which will make the estimates more realistic. This research
proposes a methodology that uses parametric, analogy and detailed estimating
techniques to enable a cost to be built for an automotive powertrain product
with a high content of new technology. The research defines a process for
segregating new or emerging technologies from current technologies to enable the
various costing techniques to be utilised. The cost drivers from an internal
combustion engine's characteristics to facilitate a cost estimate for high-
volume production are also presented. A process to enable a costing expert to
either build an estimate for the new technology under analysis or use a
comparator and then develop a variant for the new system is also discussed. Due
to the open nature of the statement ‘new technology’, research is also conducted
to provide a meaningful definition applicable to the automotive industry and
this pro
Lotus tenuis tolerates combined salinity and waterlogging: maintaining O2 transport to roots and expression of an NHX1-like gene contribute to regulation of Na+ transport
Salinity and waterlogging interact to reduce growth for most crop and pasture species. The combination of these stresses often cause a large increase in the rate of Na+ and Cl− transport to shoots; however, the mechanisms responsible for this are largely unknown. To identify mechanisms contributing to the adverse interaction between salinity and waterlogging, we compared two Lotus species with contrasting tolerances when grown under saline (200 mM NaCl) and O2-deficient (stagnant) treatments. Measurements of radial O2 loss (ROL) under stagnant conditions indicated that more O2 reaches root tips of Lotus tenuis, compared with Lotus corniculatus. Better internal aeration would contribute to maintaining Na+ and Cl− transport processes in roots of L. tenuis exposed to stagnant-plus-NaCl treatments. L. tenuis root Na+ concentrations after stagnant-plus-NaCl treatment (200 mM) were 17% higher than L. corniculatus, with 55% of the total plant Na+ being accumulated in roots, compared with only 39% for L. corniculatus. L. tenuis accumulated more Na+ in roots, presumably in vacuoles, thereby reducing transport to the shoot (25% lower than L. corniculatus). A candidate gene for vacuole Na+ accumulation, an NHX1-like gene, was cloned from L. tenuis and identity established via sequencing and yeast complementation. Transcript levels of NHX1 in L. tenuis roots under stagnant-plus-NaCl treatment were the same as for aerated NaCl, whereas L. corniculatus roots had reduced transcript levels. Enhanced O2 transport to roots enables regulation of Na+ transport processes in L. tenuis roots, contributing to tolerance to combined salinity and waterlogging stresses
Consumption smoothing and the welfare cost of uncertainty
When agents are unable to smooth consumption and have distorted beliefs about the likelihood of future income realisations, uncertainty about future states of the world has a direct effect on individual welfare. However, separating the effects of uncertainty from realised events and identifying the welfare effects of uncertainty both present a number of empirical challenges. Combining individual-level panel data from rural and urban Ethiopia with high-resolution meteorological data, we estimate the empirical relevance of uncertainty on objective consumption and subjective well-being. While negative income shocks affect both objective consumption measures and subjective well-being, greater income uncertainty only has an affect on subjective well-being. A one standard deviation change in income uncertainty is equivalent to a one standard deviation change in realised consumption. These results indicate that the welfare gains from further consumption smoothing are substantially greater than estimates based solely on consumption fluctuations
From the Germanic Soup
The translation I am presenting here is particularly complex because the poem, by the former poet laureate of Friesland, Eeltsje Hettinga, is about the German-language poet Paul Celan, his life and work, his relationship with the Austrian poet Ingeborg Bachmann, and his death in Paris in 1970. All too often there is a tendency to see the literature of minor languages as interesting only inasmuch as it fills the gaps in the canon by concentrating on its own provincial, often rural, backward-looking reality, as if the interconnectedness of the twenty-first century doesn’t extend across the whole planet or as if languages that are being pushed back into the private, familial sphere can’t be used to reflect on the literary and political world that impinges on that sphere
Bomb-<sup>14</sup>C analysis of ecosystem respiration reveals that peatland vegetation facilitates release of old carbon
The largest terrestrial-to-atmosphere carbon flux is respired CO<sub>2</sub>. However, the partitioning of soil and plant sources, understanding of contributory mechanisms, and their response to climate change are uncertain. A plant removal experiment was established within a peatland located in the UK uplands to quantify respiration derived from recently fixed plant carbon and that derived from decomposition of soil organic matter, using natural abundance <sup>13</sup>C and bomb-<sup>14</sup>C as tracers. Soil and plant respiration sources were found respectively to contribute ~ 36% and between 41-54% of the total ecosystem CO<sub>2</sub> flux. Respired CO<sub>2</sub> produced in the clipped (‘soil’) plots had a mean age of ~ 15 years since fixation from the atmosphere, whereas the <sup>14</sup>C content of ecosystem CO<sub>2</sub> was statistically indistinguishable from the contemporary atmosphere. Results of carbon mass balance modelling showed that, in addition to respiration from bulk soil and plant respired CO<sub>2</sub>, a third, much older source of CO<sub>2</sub> existed. This source, which we suggest is CO<sub>2</sub> derived from the catotelm constituted between ~ 10 and 23% of total ecosystem respiration and had a mean radiocarbon age of between several hundred to ~ 2000 years before present (BP). These findings show that plant-mediated transport of CO<sub>2</sub> produced in the catotelm may form a considerable component of peatland ecosystem respiration. The implication of this discovery is that current assumptions in terrestrial carbon models need to be re-evaluated to consider the climate sensitivity of this third source of peatland CO<sub>2</sub>
Variable response of three Trifolium repens ecotypes to soil flooding by seawater.
BACKGROUND AND AIMS: Despite concerns about the impact of rising sea levels and storm surge events on coastal ecosystems, there is remarkably little information on the response of terrestrial coastal plant species to seawater inundation. The aim of this study was to elucidate responses of a glycophyte (white clover, Trifolium repens) to short-duration soil flooding by seawater and recovery following leaching of salts. METHODS: Using plants cultivated from parent ecotypes collected from a natural soil salinity gradient, the impact of short-duration seawater soil flooding (8 or 24 h) on short-term changes in leaf salt ion and organic solute concentrations was examined, together with longer term impacts on plant growth (stolon elongation) and flowering. KEY RESULTS: There was substantial Cl(-) and Na(+) accumulation in leaves, especially for plants subjected to 24 h soil flooding with seawater, but no consistent variation linked to parent plant provenance. Proline and sucrose concentrations also increased in plants following seawater flooding of the soil. Plant growth and flowering were reduced by longer soil immersion times (seawater flooding followed by drainage and freshwater inputs), but plants originating from more saline soil responded less negatively than those from lower salinity soil. CONCLUSIONS: The accumulation of proline and sucrose indicates a potential for solute accumulation as a response to the osmotic imbalance caused by salt ions, while variation in growth and flowering responses between ecotypes points to a natural adaptive capacity for tolerance of short-duration seawater soil flooding in T. repens. Consequently, it is suggested that selection for tolerant ecotypes is possible should the predicted increase in frequency of storm surge flooding events occur
Attempts to transfer salt- and waterlogging tolerances from Sea barleygrass (Hordeum marinum Huds.) to wheat
The grandkids aren't alright: the intergenerational effects of prenatal pollution exposure
Evidence shows that environmental quality shapes human capital at birth with long-run effects on health and welfare. Do these effects, in turn, affect the economic opportunities of future generations? Using newly linked survey and administrative data, providing more than 150 million parent-child links, we show that regulationinduced improvements in air quality that an individual experienced in the womb increase the likelihood that their children, the second generation, attend college 40-50 years later. Intergenerational transmission appears to arise from greater parental resources and investments, rather than heritable, biological channels. Our findings suggest that within-generation estimates of marginal damages substantially underestimate the total welfare effects of improving environmental quality and point to the empirical relevance of environmental quality as a contributor to economic opportunity in the United States
Leaf gas films delay salt entry and enhance underwater photosynthesis and internal aeration of Melilotus siculus submerged in saline water
A combination of flooding and salinity is detrimental to most plants. We studied tolerance of complete submergence in saline water for Melilotus siculus, an annual legume with superhydrophobic leaf surfaces that retain gas films when under water. M.siculus survived complete submergence of 1 week at low salinity (up to 50molm-3 NaCl), but did not recover following de-submergence from 100molm-3 NaCl. The leaf gas films protected against direct salt ingress into the leaves when submerged in saline water, enabling underwater photosynthesis even after 3d of complete submergence. By contrast, leaves with the gas films experimentally removed suffered from substantial Na+ and Cl- intrusion and lost the capacity for underwater photosynthesis. Similarly, plants in saline water and without gas films lost more K+ than those with intact gas films. This study has demonstrated that leaf gas films reduce Na+ and Cl- ingress into leaves when submerged by saline water - the thin gas layer physically separates the floodwater from the leaf surface. This feature aids survival of plants exposed to short-term saline submergence, as well as the previously recognized beneficial effects of gas exchange under water
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