326 research outputs found
Nanoparticle enhanced evaporation of liquids: A case study of silicone oil and water
Evaporation is a fundamental physical phenomenon, of which many challenging
questions remain unanswered. Enhanced evaporation of liquids in some occasions
is of enormous practical significance. Here we report the enhanced evaporation
of the nearly permanently stable silicone oil by dispersing with nanopariticles
including CaTiO3, anatase and rutile TiO2. The results can inspire the research
of atomistic mechanism for nanoparticle enhanced evaporation and exploration of
evaporation control techniques for treatment of oil pollution and restoration
of dirty water
Cost and Benefit of Embedded Feature Annotation: A Case Study
In software industry, organizations often need to develop a set of similar software-intensive systems in order to satisfy different requirements of customers. In the literature, it has been traditionally recommended that organizations adopt Product Line Engineering-- an approach that uses a set of shared assets to derive the variants. However, in reality, organizations usually develop multiple variants using the clone-and-own approach, in which a new product is developed by cloning and modifying the assets of an existing product. Although the clone-and-own approach has several advantages, it can easily lead to inconsistencies and hardness to manage product portfolios.
In both the clone-and-own and the product line engineering context, the concept of feature can be used to characterize different variants. A feature is a function unit of a software product which provides a user-observable behavior and a unit of reuse. In the clone-and-own approach, there are two key challenges when doing cloning: reuse and consistency. For both of these activities, knowing the location of features is essential. In this thesis, we propose a lightweight approach for recording and maintaining feature models and mappings between features and software assets. We evaluated this approach in a case study, by applying it retroactively to an existing set of cloned projects in a way which simulated the actual development as if the approach had been used originally. Preliminary results showed that the extra cost of creating and maintaining a feature model and feature mapping information is negligible compared to the software development cost, and the benefit of it can justify the investment provided certain amount of reuse and consistency management is required
Research on Combustion Chamber Structure Improvement and Ignition System of Missile Turbojet Engine for Diesel Fuel
To meet the conditions of diesel ignition, this paper presents several structural improvements of a small missile turbojet engine for diesel fuel. The engine starts motor-assisted, and its fuel is ignited by silicon nitride ceramic ignitor. Theoretical analysis is performed by establishing a mathematical model of the combustion model and combustion conditions. The feasibility of diesel used as a small turbojet fuel is analyzed by using numerical simulation software. Research is carried out based on the following points: the improvement of combustion chamber and evaporator, selection of ignitor position and sustainability of fire. This paper proposed the method of linking the engine-assisting startup system and selected the right type of ignitor, and on the advanced experimental platform several groups ignition tests were carried out
New constraints on the pre-Permian continental crust growth of Central Asia (West Junggar, China) by U-Pb and Hf isotopic data from detrital zircon.
International audienceIn-situ U-Pb geochronology of detrital zircons from various Palaeozoic sedimentary rocks of West Junggar accretionary complexes (Central Asia) suggests two distinct episodes of arc magmatism, and an evolution in three steps: i) Ordovician-Silurian subduction generating juvenile arc crust; ii) Late Silurian subduction jamming, erosion and intraplate magmatism, iii) development of two new opposed Devonian-Carboniferous subductions recycling the Early Palaeozoic crust. Zircon Hf isotopes document three pre-Permian episodes of mantle-derived magmatic input into the crust: 1) Neoproterozoic (850-550 Ma), 2) Early Palaeozoic (530-450 Ma) and 3) Late Palaeozoic (380-320 Ma). Zircons also record the recycling of Neoproterozoic and Early Palaeozoic juvenile crusts during the Early and Late Palaeozoic. These data support a model of episodic continental crust growth in Central Asia
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