Influence of Varying Rockwool Fibre Length on Properties of Intumescent Coating

Intumescent coating is the most common passive fire protection for steel structure. Four formulations of intumescent coating reinforced with different Rockwool fibre lengths, i.e. 4 mm, 6 mm, 8 mm and 10 mm, and a controlled formulation, were developed and tested accordingly to investigate the influence of variable lengths on the properties of the intumescent coating and its char. In the 800oC furnace fire test, intumescent coatings expanded 6 to 10 times their initial thickness and experienced weight loss between 72-79%. The formulation with longest fibre expanded and lost weight the least and appeared to be more compact, denser and contained smaller pores. In the direct fire test of ~1022oC, formulation with longer fibre retarded flammability better, enhanced the adhesion of the coating to the steel substrate and the ability to retain its original form, and provided thermal insulation up to 85-88% of directed heat. From the char strength test, it was found that the formulation with the longest fibre has the highest strength to sustain the char structure before destruction. Degradation temperature, Td, was determined to be at ~380oC for all formulations in TGA yet residual weight increases with the increase in fibre lengths. From the XRD test, char samples of all formulations appeared to be in amorphous state and the major components determined were boron phosphate and boric acid

Forecasting bus passenger flows by using a clustering-based support vector regression approach

As a significant component of the intelligent transportation system, forecasting bus passenger flows plays a key role in resource allocation, network planning, and frequency setting. However, it remains challenging to recognize high fluctuations, nonlinearity, and periodicity of bus passenger flows due to varied destinations and departure times. For this reason, a novel forecasting model named as affinity propagation-based support vector regression (AP-SVR) is proposed based on clustering and nonlinear simulation. For the addressed approach, a clustering algorithm is first used to generate clustering-based intervals. A support vector regression (SVR) is then exploited to forecast the passenger flow for each cluster, with the use of particle swarm optimization (PSO) for obtaining the optimized parameters. Finally, the prediction results of the SVR are rearranged by chronological order rearrangement. The proposed model is tested using real bus passenger data from a bus line over four months. Experimental results demonstrate that the proposed model performs better than other peer models in terms of absolute percentage error and mean absolute percentage error. It is recommended that the deterministic clustering technique with stable cluster results (AP) can improve the forecasting performance significantly.info:eu-repo/semantics/publishedVersio

KSS unit root test of nonlinearity and nonstationarity in China’s agricultural futures markets

AbstractUnit root tests are the starting points of most economic time series analyses. Based on the nonlinear unit root test proposed by Kapetanios, Shin and Shell (KSS), this article propose a procedure to detect the presence of nonstationarity against nonlinear processes in 5 representative China’s agricultural futures markets. Our results illustrate that a unit root is rejected in favor of nonlinear trend stationary for these markets; therefore, the results in current literature based on the linear hypothesis may be spurious in understanding true market’s dynamics. We contribute to current literature in providing for the first time the empirical evidence of these facts in China’s agricultural futures markets, which is fundamentally important in relevant researches

Influence of Varying Rockwool Fibre Length on Properties of Intumescent Coating

Intumescent coating is the most common passive fire protection for steel structure. Four formulations of intumescent coating reinforced with different Rockwool fibre lengths, i.e. 4 mm, 6 mm, 8 mm and 10 mm, and a controlled formulation, were developed and tested accordingly to investigate the influence of variable lengths on the properties of the intumescent coating and its char. In the 800oC furnace fire test, intumescent coatings expanded 6 to 10 times their initial thickness and experienced weight loss between 72-79%. The formulation with longest fibre expanded and lost weight the least and appeared to be more compact, denser and contained smaller pores. In the direct fire test of ~1022oC, formulation with longer fibre retarded flammability better, enhanced the adhesion of the coating to the steel substrate and the ability to retain its original form, and provided thermal insulation up to 85-88% of directed heat. From the char strength test, it was found that the formulation with the longest fibre has the highest strength to sustain the char structure before destruction. Degradation temperature, Td, was determined to be at ~380oC for all formulations in TGA yet residual weight increases with the increase in fibre lengths. From the XRD test, char samples of all formulations appeared to be in amorphous state and the major components determined were boron phosphate and boric acid

Analytical controllability of deterministic scale-free networks and Cayley trees

According to the exact controllability theory, the controllability is investigated analytically for two typical types of self-similar bipartite networks, i.e., the classic deterministic scale-free networks and Cayley trees. Due to their self-similarity, the analytical results of the exact controllability are obtained, and the minimum sets of driver nodes (drivers) are also identified by elementary transformations on adjacency matrices. For these two types of undirected networks, no matter their links are unweighted or (nonzero) weighted, the controllability of networks and the configuration of drivers remain the same, showing a robustness to the link weights. These results have implications for the control of real networked systems with self-similarity.Comment: 7 pages, 4 figures, 1 table; revised manuscript; added discussion about the general case of DSFN; added 3 reference