2,848 research outputs found
A carbonation and chloride induced corrosion model for hot-dip galvanised reinforcement bar material in concrete
This paper focuses on methodological issues relevant to corrosion risk prediction models. A model was developed for the prediction of corrosion rates associated with hot-dip galvanised reinforcement bar material in concrete exposed to carbonation and chlorides in outdoor environment. One-year follow-up experiments, over five years, were conducted at various carbonation depths and chloride contents. The observed dependence of corrosion rate on the depth of carbonation and chloride content is complex indicating that the interaction between the carbonation and chloride influencing the corrosion. A non-linear corrosion model was proposed with statistical analysis to model the relationship between the corrosion rate and the test parameters. The main methodological contributions are (i) the proposed modeling approach able to take into account the uncertain measurement errors including unobserved systematic and random heterogeneity over different measured specimens and correlation for the same specimen across different measuring times, which best suits the measurement data; (ii) the developed model in which an interaction parameter is introduced especially to account for the contribution and the degree of the unobserved carbonation-chloride interaction. The proposed model offers greater flexibility for the modelling of measurement data than traditional models
Statistical investigation of climate change effects on the utilization of the sediment heat energy
Suvilahti, a suburb of the city of Vaasa in western Finland, was the first area to use seabed sediment heat as the main source of heating for a high number of houses. Moreover, in the same area, a unique land uplift effect is ongoing. The aim of this paper is to solve the challenges and find opportunities caused by global warming by utilizing seabed sediment energy as a renewable heat source. Measurement data of water and air temperature were analyzed, and correlations were established for the sediment temperature data using Statistical Analysis System (SAS) Enterprise Guide 7.1. software. The analysis and provisional forecast based on the autoregression integrated moving average (ARIMA) model revealed that air and water temperatures show incremental increases through time, and that sediment temperature has positive correlations with water temperature with a 2-month lag. Therefore, sediment heat energy is also expected to increase in the future. Factor analysis validations show that the data have a normal cluster and no particular outliers. This study concludes that sediment heat energy can be considered in prominent renewable production, transforming climate change into a useful solution, at least in summertime
Lambda and Anti-Lambda Hypernuclei in Relativistic Mean-field Theory
Several aspects about -hypernuclei in the relativistic mean field
theory, including the effective -nucleon coupling strengths based on
the successful effective nucleon-nucleon interaction PK1, hypernuclear magnetic
moment and -hypernuclei, have been presented. The effect of tensor
coupling in -hypernuclei and the impurity effect of to
nuclear structure have been discussed in detail.Comment: 8 pages, 2 figures, Proceedings of the Sendai International Symposium
"Strangeness in Nuclear and Hadronic Systems SENDAI08
Kondo correlation and spin-flip scattering in spin-dependent transport through a quantum dot coupled to ferromagnetic leads
We investigate the linear and nonlinear dc transport through an interacting
quantum dot connected to two ferromagnetic electrodes around Kondo regime with
spin-flip scattering in the dot. Using a slave-boson mean field approach for
the Anderson Hamiltonian having finite on-site Coulomb repulsion, we find that
a spin-flip scattering always depresses the Kondo correlation at arbitrary
polarization strength in both parallel and antiparallel alignment of the lead
magnetization and that it effectively reinforces the tunneling related
conductance in the antiparallel configuration. For systems deep in the Kondo
regime, the zero-bias single Kondo peak in the differential conductance is
split into two peaks by the intradot spin-flip scattering; while for systems
somewhat further from the Kondo center, the spin-flip process in the dot may
turn the zero-bias anomaly into a three-peak structure.Comment: 4 pages, 2 figure
Exclusive and Decays in the Universal Extra Dimension
We investigate the influence of the universal extra dimension on the
branching ratio in the decay. Taking GeV with one universal extra spatial dimension, which is
consistent with the experimental data for , ) and the electroweak precision tests, we obtain
that for both () channels the branching ratio strongly depends on the
compactification radius 1/R.Comment: 14 pages, 4 figure
Atomically flat interface between a single-terminated LaAlO3 substrate and SrTiO3 thin film is insulating
The surface termination of (100)-oriented LaAlO3 (LAO) single crystals was
examined by atomic force microscopy and optimized to produce a
single-terminated atomically flat surface by annealing. Then the atomically
flat STO film was achieved on a single-terminated LAO substrate, which is
expected to be similar to the n-type interface of two-dimensional electron gas
(2DEG), i.e., (LaO)-(TiO2). Particularly, that can serve as a mirror structure
for the typical 2DEG heterostructure to further clarify the origin of 2DEG.
This newly developed interface was determined to be highly insulating.
Additionally, this study demonstrates an approach to achieve atomically flat
film growth based on LAO substrates.Comment: 4 pages, 3 figure
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