28,735 research outputs found
THE ROLE OF CLIMATE INFORMATION IN TOURIST DESTINATION CHOICE DECISION-MAKING
This study examines if tourists actively inform themselves about the climate of their planned destination. In addition, we examine where they inform themselves and at what point in the holiday decision-making process. A self-administered questionnaire was distributed to tourists at the airport, international bus station, and the train station in Hamburg during July and August 2004. Of the 394 respondents, 73% stated that they informed themselves about the climate of their destination. Moreover, the majority of them informed themselves about climate before booking (42%). Nevertheless, a large percentage of the tourists sampled state that they informed themselves shortly before their trip. Interestingly, a significantly large share of the respondents said that they checked the weather at their destination in the week before their trip.Tourist decision-making, destination image, information search, climate, weather
Effect of the foam embellishments on the pedestrian safety of the vehicle front protection systems
Pedestrian safety related compliance requirements are very important in case of design and development of the vehicle front protection systems. Computer aided engineering impact simulations were carried out to evaluate Head Injury Criterion (HIC) of a typical bullbar impacting it with an adult headform and correlated with experimental results. Impact simulations were carried out on the same bullbar covered with semi‐rigid polyurethane foam to study the effect of foam embellishments on the pedestrian safety. Results obtained from the impact simulations were presented in this paper
High water availability increases the negative impact of a native hemiparasite on its non-native host
Environmental factors alter the impacts of parasitic plants on their hosts. However, there have been no controlled studies on how water availability modulates stem hemiparasites' effects on hosts. A glasshouse experiment was conducted to investigate the association between the Australian native stem hemiparasite Cassytha pubescens and the introduced host Ulex europaeus under high (HW) and low (LW) water supply. Cassytha pubescens had a significant, negative effect on the total biomass of U. europaeus, which was more severe in HW than LW. Regardless of watering treatment, infection significantly decreased shoot and root biomass, nodule biomass, nodule biomass per unit root biomass, F-v/F-m, and nitrogen concentration of U. europaeus. Host spine sodium concentration significantly increased in response to infection in LW but not HW conditions. Host water potential was significantly higher in HW than in LW, which may have allowed the parasite to maintain higher stomatal conductances in HW. In support of this, the delta C-13 of the parasite was significantly lower in HW than in LW (and significantly higher than the host). C. pubescens also had significantly higher F-v/F-m and 66% higher biomass per unit host in the HW compared with the LW treatment. The data suggest that the enhanced performance of C. pubescens in HW resulted in higher parasite growth rates and thus a larger demand for resources from the host, leading to poorer host performance in HW compared with LW. C. pubescens should more negatively affect U. europaeus growth under wet conditions rather than under dry conditions in the field
FIR Filter Implementation by Efficient Sharing of Horizontal and Vertical Common Sub-expressions
No abstract availabl
Radioactive silicon as a marker in thin-film silicide formation
A new technique using radioactive 31Si (half-life =2.62 h), formed in a nuclear reactor, as a marker for studying silicide formation is described. A few hundred angstroms of radioactive silicon is first deposited onto the silicon substrate, followed immediately by the deposition of a few thousand angstroms of the metal. When the sample is heated, a silicide is first formed with the radioactive silicon. Upon further silicide formation, this band of radioactive silicide can move to the surface of the sample if silicide formation takes place by diffusion of the metal or by silicon substitutional and/or vacancy diffusion. However, if the band of radioactive silicide stays at the silicon substrate interface it can be concluded that silicon diffuses by interstitial and/or grain-boundary diffusion. This technique was tested by studying the formation of Ni2Si on silicon at 330 °C. From a combination of ion-beam sputtering, radioactivity measurement, and Rutherford backscattering it is found that the band of radioactive silicide moves to the surface of the sample during silicide formation. From these results, implanted noble-gas marker studies and the rate dependence of Ni2Si growth on grain size, it is concluded that nickel is the dominant diffusing species during Ni2Si formation, and that it moves by grain-boundary diffusion
Dissociation mechanism for solid-phase epitaxy of silicon in the Si <100>/Pd2Si/Si (amorphous) system
Solid-phase epitaxial growth (SPEG) of silicon was investigated by a tracer technique using radioactive 31Si formed by neutron activation in a nuclear reactor. After depositing Pd and Si onto activated single-crystal silicon substrates, Pd2Si was formed with about equal amounts of radioactive and nonradioactive Si during heating at 400 °C for 5 min. After an 1-sec annealing stage (450-->500 °C in 1 h) this silicide layer, which moves to the top of the sample during SPEG, is etched off with aqua regia. From the absence of radioactive 31Si in the etch, it is concluded that SPEG takes place by a dissociation mechanism rather than by diffusion
Compensating impurity effect on epitaxial regrowth rate of amorphized Si
The epitaxial regrowth of ion-implanted amorphous layers on Si with partly compensated doping profiles of 11B, 75As, and 31P was studied. Single implants of these impurities are found to increase the regrowth rate at 475 and 500°C. The compensated layers with equal concentrations of 11B and 31P or 11B and 75As show a strong decrease of the regrowth whereas for the layers with overlapping 75As and 31P profiles no compensation has been found
Ti and V layers retard interaction between Al films and polycrystalline Si
Fine-grained polycrystalline Si (poly Si) in contact with Al films recrystallizes at temperatures well below the Si-Al eutectic (577 °C). We show that this interaction can be deferred or suppressed by placing a buffer layer of Ti or V between the Al film and the poly Si. During annealing, Ti or V form TiAl3 or Val3 at the buffer-layer–Al-film interface, but do not react with the poly Si so that the integrity of the poly Si is preserved as long as some unreacted Ti or V remains. The reaction between the Ti or V layer and the Al film is transport limited ([proportional]t^1/2) and characterized by the diffusion constants 1.5×10^15 exp(–1.8eV/kT) Å^2/sec or 8.4×10^12 exp(–1.7eV/kT) Å^2/sec, respectively
Sequence of phase formation in planar metal-Si reaction couples
A correlation is found between the sequence of phase formation in thin-film metal-Si interactions and the bulk equilibrium phase diagram. After formation of the first silicide phase, which generally follows the rule proposed by Walser and Bené, the next phase formed at the interface between the first phase and the remaining element (Si or metal) is the nearest congruently melting compound richer in the unreacted element. If the compounds between the first phase and the remaining element are all noncongruently melting compounds (such as peritectic or peritectoid phases), the next phase formed is that with the smallest temperature difference between the liquidus curve and the peritectic (or peritectoid) point
Structural difference rule for amorphous alloy formation by ion mixing
We formulate a rule which establishes a sufficient condition that an amorphous binary alloy will be formed by ion mixing of multilayered samples when the two constituent metals are of different crystalline structure, regardless of their atomic sizes and electronegativities. The rule is supported by the experimental results we have obtained on six selected binary metal systems, as well as by the previous data reported in the literature. The amorphization mechanism is discussed in terms of the competition between two different structures resulting in frustration of the crystallization process
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