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61.
Electric vehicles (EVs) and plug-in hybrid electric vehicles (PHEVs), which obtain their fuel from the grid by charging a battery, are set to be introduced into the mass market and expected to contribute to oil consumption reduction. In this research, scenarios for 2020 EVs penetration and charging profiles are studied integrated with different hypotheses for electricity production mix. The impacts in load profiles, spot electricity prices and emissions are obtained for the Portuguese case study. Simulations for year 2020, in a scenario of low hydro production and high prices, resulted in energy costs for EVs recharge of 20 cents/kWh, with 2 million EVs charging mainly at evening peak hours. On the other hand, in an off-peak recharge, a high hydro production and low wholesale prices' scenario, recharge costs could be reduced to 5.6 cents/kWh. In these extreme cases, EV's energy prices were between 0.9€ to 3.2€ per 100 km. Reductions in primary energy consumption, fossil fuels use and CO2 emissions of up to 3%, 14% and 10%, respectively, were verified (for a 2 million EVs' penetration and a dry year's off-peak recharge scenario) from the transportation and electricity sectors together when compared with a BAU scenario without EVs.  相似文献   
62.
Intrinsic ZnO thin film layers have previously been deposited using the dip-ILGAR ‘Ion Layer Gas Reaction’ method. This deposition method and material has been effectively employed to deposit the buffer layers in chalcopyrite solar cells [M. Bär, H.-J. Muffler, Ch.-H. Fischer, S. Zweigart, F. Karg, M.C. Lux-Steiner Prog. Photovolt: Res. Appl. 10 (2002) 173]. The original parameters for the ZnO dip ILGAR deposition process were optimised for film quality. These parameters, however, were not suitable for an up-scaled technology transfer to tape deposition as the dip speed and growth rate meant impractically long deposition times. The results presented here are from an investigation, using the laboratory scale ILGAR apparatus with 2.5 × 5 cm2 substrates, into parameters e.g. solvent, salt and apparatus parameters, which could allow an increased deposition rate and dip speed yet retains film quality. Simple dip mechanics and the Landau-Levich equation, which describes film thickness as a function of dip withdrawal speed, gravitational acceleration and the properties of the solution, are considered. The recently optimised deposition parameters given here will allow a dip speed of more than 7 m/min and deposition rate of 7.5 nm/cycle.  相似文献   
63.
The effects of temperature, frequency, and environment on the tensile and cyclic deformation behavior of a nickel aluminide alloy, Ni-9.0 wt pct Al-7.97 pct Cr-1.77 pct Zr (IC-221), have been determined. The tensile properties were obtained in vacuum at elevated temperatures and in air at room temperature. The alloy was not notch sensitive at room temperature or at 600 °C, unlike Cr-free Ni3Al + B alloys. In general, crack growth rates of IC-221 increased with increasing temperature, decreasing frequency, exposure to air, or testing at higherR ratios. At 25 °C, crack growth rates were slightly higher than for a previously investigated Cr-free Ni3Al alloy. However, at 600 °C, the crack growth rates for IC-221 were lower than for the Cr-free alloy. Substantial frequency effects were noted on crack growth of IC-221 at both 600 °C and 800 °C in both air and vacuum, especially at highK. The relative contributions of creep and environmental interactions to fatigue crack growth are discussed.  相似文献   
64.
Several amyloid-forming proteins are characterized by the presence of hydrophobic and highly amyloidogenic core sequences that play critical roles in the initiation and progression of amyloid fibril formation. Therefore targeting these sequences represents a viable strategy for identifying candidate molecules that could interfere with amyloid formation and toxicity of the parent proteins. However, the highly amyloidogenic and insoluble nature of these sequences has hampered efforts to develop high-throughput fibrillization assays. Here we describe the design and characterization of host-guest switch peptides that can be used for in vitro mechanistic and screening studies that are aimed at discovering aggregation inhibitors that target highly amyloidogenic sequences. These model systems are based on a host-guest system where the amyloidogenic sequence (guest peptide) is flanked by two beta-sheet-promoting (Leu-Ser)(n) oligomers as host sequences. Two host-guest peptides were prepared by using the hydrophobic core of Abeta comprising residues 14-24 (HQKLVFFAEDV) as the guest peptide with switch elements inserted within (peptide 1) or at the N and C termini of the guest peptide (peptide 2). Both model peptides can be triggered to undergo rapid self-assembly and amyloid formation in a highly controllable manner and their fibrillization kinetics is tuneable by manipulating solution conditions (for example, peptide concentration and pH). The fibrillization of both peptides reproduces many features of the full-length Abeta peptides and can be inhibited by known inhibitors of Abeta fibril formation. Our results suggest that this approach can be extended to other amyloid proteins and should facilitate the discovery of small-molecule aggregation inhibitors and the development of more efficacious anti-amyloid agents to treat and/or reverse the pathogenesis of neurodegenerative and systemic amyloid diseases.  相似文献   
65.
We have conducted a cohort study of cancer risks among 140,208 Swedish farmers in order to compare their cancer risks with those of the general male population. Since there were no individual data regarding exposure to agricultural chemicals and acquiring such data was not realistic, we obtained crude and hypothetical estimates for exposure by dividing the data into time periods, year-of-birth cohorts and geographical areas. The cohort was followed-up in the Cancer Environment Register from 1 January 1971 either until death or until 31 December 1987. The relative risk was computed as the ratio of the observed and expected number of cases (SIR = standardized incidence ratio). A total of 15,040 cases were observed vs 18,918 expected, resulting in a statistically significant decreased SIR of 0.80 (95% confidence interval: 0.78-0.81). The SIR was significantly decreased for several cancer sites, and the lowest value was found for tongue, lung, oesophagus, liver and urinary organs, which is in agreement with other studies on cancer risks among farmers. Other major cancer sites with decreased SIRs were the colon, rectum, pancreas and kidney. Lip cancer and multiple myeloma showed statistically significant increased risks. SIRs for stomach cancer, prostate cancer, skin carcinoma, malignant melanoma, tumours in connective tissue or muscle, malignant lymphomas and leukaemia were all close to unity, which is not consistent with several other studies that have shown increased risks for these sites. For malignant lymphomas the SIR increased over time, though not significantly, and was highest among younger farmers. The SIR for non-Hodgkin lymphoma was lowest in the northernmost region. This gives some support to the hypothesis that there is an association between non-Hodgkin lymphoma and exposure to pesticides and other agricultural chemicals. It is of note that the SIR for multiple myeloma was significantly increased in those parts of Sweden where the use of pesticides has been less frequent and in lower amounts.  相似文献   
66.
Copper (Cu) is essential to various physiological processes in marine organisms. However, at high concentrations this redox-active transition metal may enhance the formation of reactive oxygen species (ROS) and subsequently initiate oxidative damage. High concentrations of Cu may increase oxidative damage to lipids, proteins and DNA. Bathymodiolus azoricus is a Mytilid bivalve very common in hydrothermal environments near the Azores Triple Junction continuously exposed to high metal concentrations, including Cu, emanating from the vent fluids. The knowledge of antioxidant defence system and other stress related biomarkers in these organisms is still scarce. The aim of this work was to study the effect of Cu (25 microg l(-1); 24 days exposure; 6 days depuration) on the antioxidant stress biomarkers in the gills and mantle of B. azoricus. The expression of stress related biomarkers was tissue-dependent and results suggest that other factors than metal exposure may influence stress biomarkers, since little variation in antioxidant enzymes activities, MT concentrations, LPO and total oxyradical scavenging capacity (TOSC) occurred in both control and Cu-exposed mussels. Moreover, there is a general tendency for these parameters to increase with time, in both control and Cu-exposed mussels, suggesting that reactive oxygen species (ROS) formation is not metal dependent, and may be related with poor physiological conditions of the animals after long periods in adverse conditions compared to those in hydrothermal environments.  相似文献   
67.
The mechanical behavior of three CVT-processed 2D woven SiC/BN/SiC composite materials with different initial BN interphase thicknesses has been investigated by means of tensile and impact tests. The results have established the efficiency of a BN interphase in promoting a nonlinear/non–catastrophic tensile behavior and high impact resistance. The effect of the initial BN interphase thickness on the resulting mechanical behavior has also been demonstrated. Characterization of the fiber/matrix interfacial zones by AES and TEM has revealed the presence of a SiO2/C double layer at the BN/fiber interface, which might result from a decomposition undergone by the Si–C(O) Nicalon fiber during processing. It has been suggested that the influence of the initial BN interphase thickness on the mechanical properties of the composites results from both changes occurring in the composition and morphology of the interfacial zones and modifications of the interfacial forces due to accommodation of the radial residual clamping stress.  相似文献   
68.
The oxidation behavior of a 2D woven C/SiC composite partly protected with a SiC seal coating and heat-treated (stabilized) at 1600°C in inert gas has been investigated through an experimental approach based on thermogravimetric analyses and optical/electron microscopy. Results of the tests, performed under flowing oxygen, have shown that the oxidation behavior of the composite material in terms of oxidation kinetics and morphological evolutions is related to the presence of thermal microcracks in the seal coating as well as in the matrix. Three different temperature domains exist. At low temperatures (<800°C), the mechanisms of reaction between carbon and oxygen control the oxidation kinetics and are associated with a uniform degradation of the carbon reinforcement. At intermediate temperatures, (between 800° and 1100°C), the oxidation kinetics are controlled by the gas-phase diffusion through a network of microcracks in the SiC coating, resulting in a nonuniform degradation of the carbon phases. At high temperatures (>1100°C), such diffusion mechanisms are limited by sealing of the microcracks by silica; therefore, the degradation of the composite remains superficial. The study of the oxidation behavior of (i) the heat-treated composite in a lower oxygen content environment (dry air) and (ii) the as-processed (unstabilized) composite in dry oxygen confirms the different mechanisms proposed to explain the oxidation behavior of the composite material.  相似文献   
69.
70.
Local extraction electrodes offer several crucial advantages for operation of atom probes. Because of the proximity of the local extraction electrode to the specimen, the electric field produced at the specimen apex by a given voltage is enhanced and the voltage required for field evaporation is reduced. In a voltage-pulsed atom probe, the absolute magnitude of the energy uncertainty is correspondingly reduced. High mass resolution (m/deltam > 1000) may therefore be obtained by accelerating the evaporated ions to a greater total potential after the local extraction electrode. The low extraction voltage may also be pulsed rapidly (100 ps rise time) and at high repetition rates (up to 10(5) pulses per second) using currently available solid-state pulsers. Furthermore, a local electrode and intermediate electrodes may be used as optical elements to control the image magnification. All of these benefits may be applied to any type of atom probe. Local-electrode atom probes (LEAP) should be especially advantageous for developing three-dimensional atom probes with high mass resolution and a large field of view. A sample has been developed that consists of many microtips formed on a planar sample using ion beam mask etching. Microtip samples are especially suited to LEAP. Analysis of electrically insulating samples may also be possible with microtip samples in a LEAP. This combination of features suggests flexible, high speed, high mass resolution atom probes that can work with either conventional needle-shaped specimens or the new style of planar microtip specimens.  相似文献   
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