2,220 research outputs found
Software Specification Based on Re-usable Business Components
No full textElectrical Engineering, Mathematics and Computer Scienc
sj-docx-1-jdr-10.1177_00220345231158269 – Supplemental material for Ligature-Induced Periodontitis Drives Colorectal Cancer: An Experimental Model in Mice
No full textSupplemental material, sj-docx-1-jdr-10.1177_00220345231158269 for Ligature-Induced Periodontitis Drives Colorectal Cancer: An Experimental Model in Mice by Y.T. Shi, J.M. He, Z.A. Tong, Y.J. Qian, Q.W. Wang, D.J.C. Jia, W.J. Zhu, Y.X. Zhao, B.B. Cai, S.J. Chen and M.S. Si in Journal of Dental Research</p
Effect of gamma-ray irradiation on trap characteristics of polyethylene based micro/nanocomposites
No full textAs the main insulating material of nuclear power plant cables, polyethylene is exposed to high temperatures and irradiation and its service life is shortened. It is crucial to improve the insulating and electrical properties of irradiated polyethylene. In this study, low-density polyethylene (LDPE) based Boron Nitride (mathrm {B}mathrm {N})/mathrm {S}mathrm {i}mathrm {O}-{2} Micro/nanocomposites have been prepared to investigate the effect gamma-ray irradiation on the trap characteristics. The irradiation was carried out in air and the total dose was 0mathrm {k}mathrm {G}mathrm {y}, 100mathrm {k}mathrm {G}mathrm {y}, 500mathrm {k}mathrm {G}mathrm {y} and 1000~mathrm {k}mathrm {G}mathrm {y}. The surface potential decay of gamma-irradiated composites filled with various contents of micro- and nano-sized particles was measured, and the trap distribution and the carrier mobility of composites could be obtained. It was found that the trap depth decreased as the total dose increased from 0 mathrm {k}mathrm {G}mathrm {y} to 1000~mathrm {k}mathrm {G}mathrm {y}. The trap depth of the composites containing 20 wt% micro-BN and 5 wt% nano-SiO2 did not change significantly with the growth of irradiation dose. It is considered that the addition of micro- and nano- particles plays a better role in hindering the chemical reactions such as crosslinking and oxidation.</p
Multiband photoluminescence from carbon nanoflakes synthesized by hot filament CVD: towards solid-state white light sources
No full textCarbon nanoflakes (CNFLs) are synthesized on silicon substrates deposited with carbon islands in a methane environment using hot filament chemical vapor deposition. The structure and composition of the CNFLs are studied using field emission scanning electron microscopy, high-resolution transmission electron microscopy, micro-Raman spectroscopy, and X-ray photoelectron spectroscopy. The results indicate that the CNFLs are composed of multilayer graphitic sheets and the area and thickness of CNFs increase with the growth time. The photoluminescence (PL) of CNFLs excited by a 325 nm He-Cd laser exhibits three strong bands centered at 408, 526, and 699 nm, which are related to the chemical radicals terminated on the CNFLs and the associated interband transitions. The PL results indicate that the CNFLs are promising as an advanced nano-carbon material capable of generating white light emission. These outcomes are significant to control the electronic structure of CNFLs and contribute to the development of next-generation solid-state white light emission devices. © 2014 the Partner Organisations
Sediment exchange between flats and channels in tidal inlets
No full textThe subject of this thesis is the sediment exchange between channels and flats in tidal inlets. This topic is part of a research scheme which must yield more insight into the dynamic equilibrium of tidal inlets. An important aspect of the sediment exchange is the drying and flooding of the flats during the tide. The oscillating water level gives rise to velocity variations which cause stirring and settling of sediment. In nature, tidal inlets are large and complex systems, the dimensions of which vary continuously due to natural effects (tide, storms, sea level rise). For the purpose of this study a schematised tidal inlet is considered, with dimensions as occurring in the Dutch Wadden Sea. In this schematisation, the bottom ofthe channel and the tidal flats is fixed. The schematisation is used as a starting point to model the water and sediment motion during a few tidal cycles. Subsequently the output of each model run, i.e. velocities, water depths and concentrations, is used to estimate the sediment transport during ebb and flood, respectively. The transport is calculated in points along a line perpendicular to the channel axis. Model runs are executed in one and two dimensions. Sediment transport rates according to power law formula (l-D and 2-D cases) and according to a suspended sediment equation (l-D cases only) are compared. The suspended sediment fluxes at the flat agree well with the sediment transport rates determined by the power law formula. In some of the I-D runs, it appears that problems occur around the transition from the flat to the channel. Very large values of the transport rate, much larger than those in the adjacent cells, result from a thin water film with relatively high velocities. Therefore, the sediment transport model is provided with a water depth threshold preventing this. The threshold hardly influences the sediment transport rates during flood, either suspended or by power law, because the front of the wave is rather steep. The sediment transport rates during ebb, however, for which the threshold was meant, are reduced, such that the transport rate approaches the values in the surrounding points. The parameters which have been chosen to vary in the I-D model runs are: the slope of the tidal flat, in order to investigate whether an equilibrium profile of the tidal flat is possible, and to investigate the net transport over the landward edge of the flat if the flat is relatively steep, the (a)symmetry ofthe imposed water level in order to compare the results of a symmetric boundary condition to the results of a flood-dominant condition; the water level in the channel changes with time towards the end ofthe channel, the tidal amplitude and the length ofthe tidal flat, in order to assess how they are related to the sediment transport.Hydraulic EngineeringCivil Engineering and Geoscience
The effect of temperature on the mechanism of photoluminescence from plasma-nucleated, nitrogenated carbon nanotips
No full textNitrogenated carbon nanotips (NCNTPs) have been synthesized using customized plasma-enhanced hot filament chemical vapor deposition. The morphological, structural, and photoluminescent properties of the NCNTPs are investigated using scanning and transmission electron microscopy, X-ray photoelectron spectroscopy, Raman spectroscopy, and photoluminescence spectroscopy. The photoluminescence measurements show that the NCNTPs predominantly emit a green band at room temperature while strong blue emission is generated at 77 K. It is shown that these very different emission behaviors are related to the change of the optical band-gap and the concentration of the paramagnetic defects of the carbon nanotips. The studies shed light on the controversies on the photoluminescence mechanisms of carbon-based amorphous films measured at different temperatures. The relevance of the results to the use of nitrogenated carbon nanotips in light-emitting optoelectronic devices is discussed
Distributed human computation framework for linked data co-reference resolution
No full textDistributed Human Computation (DHC) is a technique used to solve computational problems by incorporating the collaborative effort of a large number of humans. It is also a solution to AI-complete problems such as natural language processing. The Semantic Web with its root in AI is envisioned to be a decentralised world-wide information space for sharing machine-readable data with minimal integration costs. There are many research problems in the Semantic Web that are considered as AI-complete problems. An example is co-reference resolution, which involves determining whether different URIs refer to the same entity. This is considered to be a significant hurdle to overcome in the realisation of large-scale Semantic Web applications. In this paper, we propose a framework for building a DHC system on top of the Linked Data Cloud to solve various computational problems. To demonstrate the concept, we are focusing on handling the co-reference resolution in the Semantic Web when integrating distributed datasets. The traditional way to solve this problem is to design machine-learning algorithms. However, they are often computationally expensive, error-prone and do not scale. We designed a DHC system named iamResearcher, which solves the scientific publication author identity co-reference problem when integrating distributed bibliographic datasets. In our system, we aggregated 6 million bibliographic data from various publication repositories. Users can sign up to the system to audit and align their own publications, thus solving the co-reference problem in a distributed manner. The aggregated results are published to the Linked Data Cloud
Monte Carlo simulation of HERD calorimeter
No full textThe High Energy cosmic-Radiation Detection (HERD) facility onboard China's Space Station is planned for operation starting around 2020 for about 10 years. It is designed as a next generation space facility focused on indirect dark matter search, precise cosmic ray spectrum and composition measurements up to the knee energy, and high energy gamma-ray monitoring and survey. The calorimeter plays an essential role in the main scientific objectives of HERD. A 3-D cubic calorimeter filled with high granularity crystals as active material is a very promising choice for the calorimeter. HERD is mainly composed of a 3-D calorimeter (CALO) surrounded by silicon trackers (TK) from all five sides except the bottom. CALO is made of 9261 cubes of LYSO crystals, corresponding to about 55 radiation lengths and 3 nuclear interaction lengths, respectively. Here the simulation results of the performance of CALO with GEANT4 and FLUKA are presented: 1) the total absorption CALO and its absorption depth for precise energy measurements (energy resolution: 1% for electrons and gammarays beyond 100 GeV, 20% for protons from 100 GeV to 1 PeV); 2) its granularity for particle identification (electron/proton separation power better than 10-5); 3) the homogenous geometry for detecting particles arriving from every unblocked direction for large effective geometrical factor (2sr for electron and diffuse gammarays, >2 m2sr for cosmic ray nuclei); 4) expected observational results such as gamma-ray line spectrum from dark matter annihilation and spectrum measurement of various cosmic ray chemical components. © 2014 SPIE
Enhancement of electron field emission of vertically aligned carbon nanotubes by nitrogen plasma treatment
No full textThe electron field emission (EFE) characteristics from vertically aligned carbon nanotubes (VACNTs) without and with treatment by the nitrogen plasma are investigated. The VACNTs with the plasma treatment showed a significant improvement in the EFE property compared to the untreated VACNTs. The morphological, structural, and compositional properties of the VACNTs are extensively examined by scanning electron microscopy, transmission electron microscopy, Raman spectroscopy, and energy dispersive X-ray spectroscopy. It is shown that the significant EFE improvement of the VACNTs after the nitrogen plasma treatment is closely related to the variation of the morphological and structural properties of the VACNTs. The high current density (299.6 μA/cm2) achieved at a low applied field (3.50 V/μm) suggests that the VACNTs after nitrogen plasma treatment can serve as effective electron field emission sources for numerous applications
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