A Hybrid Model Based on Support Vector Machine for Bus Travel-Time Prediction

Effective bus travel time prediction is essential in transit operation system. An improved support vector machine (SVM) is applied in this paper to predict bus travel time and then the efficiency of the improved SVM is checked. The improved SVM is the combination of traditional SVM, Grubbs’ test method and an adaptive algorithm for bus travel-time prediction. Since error data exists in the collected data, Grubbs’ test method is used for removing outliers from input data before applying the traditional SVM model. Besides, to decrease the influence of the historical data in different stages on the forecast result of the traditional SVM, an adaptive algorithm is adopted to dynamically decrease the forecast error. Finally, the proposed approach is tested with the data of No. 232 bus route in Shenyang. The results show that the improved SVM has good prediction accuracy and practicality

Macrophyte identity shapes water column and sediment bacterial community

By assembling mesocosms and utilizing high-throughput sequencing, we aim to characterize the shifts of the bacterial community in freshwaters driven by two contrasting submerged macrophyte species, Ceratophyllum demersum L. and Vallisneria spiralis L. Although the microbe in both the water column and sediment were largely modulated by the macrophyte, the effect varied considerably depending on bacterial locations and macrophyte species. Actinobacteria was the most abundant taxa in the water column of all the three treatments, but its abundances were significantly higher in the two planted treatments. Moreover, Alphaproteobacteria showed high abundance only in the unplanted control. For bacterial taxa in the sediment, C. demersum significantly increased the relative abundance of Anaerolineae but reduced the relative abundance of Betaproteobacteria and Gammaproteobacteria, while V. spiralis increased the relative abundance of Deltaproteobacteria and Gammaproteobacteria. Additionally, in the C. demersum treatment, the water column bacterial community increased more dramatically in richness, alpha diversity, and the relative abundance of the dominant taxa than those in the V. spiralis treatment. Taken together, the findings from this study reveal that the two species of submerged macrophyte modified the bacterial community in waters, despite the obvious interspecific performance differences

Simultaneous sampling of volatile and non-volatile analytes in beer for fast fingerprinting by extractive electrospray ionization mass spectrometry

By gently bubbling nitrogen gas through beer, an effervescent beverage, both volatile and non-volatile compounds can be simultaneously sampled in the form of aerosol. This allows for fast (within seconds) fingerprinting by extractive electrospray ionization mass spectrometry (EESI-MS) in both negative and positive ion mode, without the need for any sample pre-treatment such as degassing and dilution. Trace analytes such as volatile esters (e.g., ethyl acetate and isoamyl acetate), free fatty acids (e.g., caproic acid, caprylic acid, and capric acid), semi/non-volatile organic/inorganic acids (e.g., lactic acid), and various amino acids, commonly present in beer at the low parts per million or at sub-ppm levels, were detected and identified based on tandem MS data. Furthermore, the appearance of solvent cluster ions in the mass spectra gives insight into the sampling and ionization mechanisms: aerosol droplets containing semi/non-volatile substances are thought to be generated via bubble bursting at the surface of the liquid; these neutral aerosol droplets then collide with the charged primary electrospray ionization droplets, followed by analyte extraction, desolvation, ionization, and MS detection. With principal component analysis, several beer samples were successfully differentiated. Therefore, the present study successfully extends the applicability of EESI-MS to the direct analysis of complex liquid samples with high gas content. Figure By gently bubbling nitrogen gas through beer, both volatile and non-volatile compounds can be simultaneously sampled in the form of aerosol for further analysis, allowing fast chemically fingerprinting using extractive electrospray ionization mass spectrometry (EESI-MS

Numerical Investigation of the Influence of Precooling on the Thermal Performance of a Borehole Heat Exchanger

Ground source heat pumps (GSHPs), a high-efficiency and energy-saving air-conditioning technology that utilizes shallow geothermal resources for both heating and cooling, are a vital green energy system for residential and commercial buildings. Improving the performance of such a system was the focus of the current research. As soil temperature and thermal radius are two important aspects that affect the performance of ground source heat pump systems, we conducted a new numerical simulation to capture the changes in sensitive factors and propose the optimized paths. The numerical simulation analyzed the thermal characteristics of a borefield under different pre-cooling times and soil types. The results indicated the following: (1) The rate of the ground temperature change with pre-cooling during the discharging period had a faster rise than in the case without pre-cooling. The longer the precooling time was, the smaller the thermal radius became. In particular, when the precooling time was longer than 14 days, the decrease in the thermal radius rate percentages was less than 4%. (2) Among the three kinds of soils compared, the soils with lower thermal conductivity and thermal diffusivity best suppressed the thermal interference effects. (3) Using a multivariate nonlinear function regression model, a simulation formula was proposed to predict- the thermal radius, which considered the factors of thermal diffusivity, precooling time, and discharging time. The prediction deviation was within 14.8%

Chemical Oxidative Kinetic Study of Arsenopyrite Dissolved by Iron Solution

To extract the Au efficiently, the kinetic experiments were performed in a 1000 mL-glass bulbs which were made by us to determine the oxidative dissolution of arsenopyrite by iron solution. The results show that the rate of dissolution of arsenopyrite increases with the increasing of temperature from 30 degrees C to 75 degrees C, in which an apparent activation energy for arsenopyrite oxidation is 10.850 kJ.mol(-1). Moreover, the rate of oxidative dissolution of arsenopyrite increases with the increasing of concentration of ferric iron with the reaction order is 0.34 (4.62 similar to 40.04 g.L-1) and 0.61 (27.32 similar to 36.33 g.L-1). In contrast, the reduction of hydrogen ion can promote concentration promotes the leaching rate of arsenopyrite with the reaction order of -0.29

Responses of water quality and phytoplankton assemblages to remediation projects in two hypereutrophic tributaries of Chaohu Lake

Water shortages and the presence of point and diffuse source pollution have caused a serious deterioration in water quality in two tributaries (the Tangxi River and Shiwuli River) of Chaohu Lake, China. To reduce nutrient pollution and suppress harmful algal blooms (HABs), hard engineering and ecological remediation projects were implemented. A post-project investigation from 2013 to 2016 was carried out to evaluate the outcome of the remediation projects by monitoring the seasonal and spatial variations in water quality and the phytoplankton community. In the Tangxi River, the average total phosphorus (TP) concentrations in the four seasons were below 0.5 mg L-1, with the lowest concentration (0.29 +/- 0.12 mg L-1) found in autumn. Remediation measures including sediment dredging, riparian buffer zone creation, downstream wetland park construction, and water augmentation using reclaimed water and filtered lake water might combine to promote P source mitigation. Moreover, the percentage of bloom-forming cyanobacteria (i.e., Microcystis, Aphanizomenon, Anabaena, Osanatoria, Phormidium and Planktothrix) in the phytoplankton assemblage and the biomass of the dominant species indicated successful HAB control. In the Shiwuli River, water quality improvements and phytoplankton responses have been observed since 2015 after the upgrading of a local wastewater treatment plant (WWTP) with effluent that was used for flow augmentation. Nevertheless, there is still room for improvement via increasing the river self-purification ability (e.g., the creation of downstream wetlands and riparian buffer zones) and promoting water augmentation according to the experience gained in the remediation projects of the Tangxi River.</p

Why Zijinshan copper bioheapleaching plant works efficiently at low microbial activity - Study on leaching kinetics of copper sulfides and its implications

Zijinshan commercial bioheapleaching-SX-EW plant has been in operation since December 2005. 13.9 million tonnes of low grade copper sulfide ore (Cu 0.38%) has been leached efficiently with an annual recovery of 80% in this distinct leaching system with high iron concentration, high temperature, high acidity and low microbial activity. This paper is to study the key factors which influence the heap operation in Zijinshan. Dissolution kinetics of diginite and covellite was carried out in acid ferric sulfate solution under controlled redox potential. Moreover, column bioleaching tests were conducted in the laboratory with raffinate from the plant. Both results showed that the main factors accelerating dissolution rate of Cu1.8S/CuS were mainly temperature and ferric concentration, while redox potential only had a slight positive effect. The present work provides an insight into mineral kinetics to understand this unique bioheapleaching operation and gives further information for optimization of the existing practices. (c) 2013 Elsevier Ltd. All rights reserved

A Study of the Spatial Structure and Regional Interaction of Agricultural Green Total Factor Productivity in China Based on SNA and VAR Methods

As regional interaction increases in an open economy, a region’s green total factor productivity in agriculture must be considered alongside relationships with other regions. In this study, the slack-based model (SBM) global Malmquist–Luenberger (GML) index is used to measure the green total factor productivity of agriculture in each province of China, and the social network analysis (SNA) and vector autoregressive model (VAR) impulse response function (IRF) are used to examine the spatial network structure and regional interactivity. The research confirms that the absolute value and concentration of agricultural green total factor productivity are generally higher in the south than in the north of China, but the peak is lower in the south than in the north. The network density of agricultural green total factor productivity in China from 2008 to 2019 shows an increase, with the cut-off values of mean, 10, 50, and 100 treated as 4.97%, 2.57%, 3.30%, and 2.43%, respectively. From 2008 to 2019, the central potentials of network entry and network exit of green total factor productivity in China’s agriculture show a “V”-shaped and inverted “V”-shaped evolution path, respectively, with the density of cohesive subgroups growing, which demonstrates that the spatial structure of green total factor productivity in Chinese agriculture has experienced an evolutionary path from polycentric to monocentric to polycentric conditions. The spatial interaction of different cohesive subgroups is intensifying and has a certain degree of self-stability. In terms of regional interaction, the siphon effect of the east on the green development of agriculture in the central and western regions is significant, but the trickle-down effect is not obvious, and the interaction between the central and western regions has a catalytic effect on the efficiency of the green economy of agriculture in both regions. It is recommended that targeted policies be introduced to support the flow of agricultural factors and industrial division of labour between the central and western regions and the south and north, taking into account the actual situation. The novelty of this paper is that it focuses on the green total factor productivity of Chinese agriculture and combines the innovative use of the social network analysis paradigm to analyse the green development of agriculture in a country from a spatial dynamic evolutionary perspective. A limitation of the research methodology in this paper is its poor applicability to closed economy analysis

Influence of Ca on the mechanical properties and microstructures of slag-fly ash geopolymers

A deep understanding of the role of Ca in geopolymers exposed to various environments is essential for geopolymerization. This work evaluates the role of Ca by observing the behavior of hierarchically calciferous geopolymers under different environments including air, carbonization and freezing-thawing cycles. The structural and morphological differences between the geopolymers and the related mechanisms in various environmental conditions are assessed based on compressive strength, brunauer emmett teller, X-ray diffraction, fourier transform infrared spectoscopy, nuclear magnetic resonance spectroscopy and scanning electron microscopy measurements. It is found that two kinds of geopolymer gels, calcium silicate hydrate and sodium aluminosilicate hydrate, are formed in the geopolymerization of blast furnace slag and fly ash. Regardless of the specific air, carbonization or freezing-thawing cycle environment, the former gel dominates the properties in low Ca geopolymers, while the latter gel determines the properties in medium and high Ca geopolymers. Moreover, the carbonization environment enables calciferous geopolymers with higher surface areas and smaller pore sizes. Such adequate pore structures can significantly improve the performance of the geopolymers. This study presents novel insights into the influence of Ca on geopolymerization and in strengthening geopolymer properties

High-density Lipoprotein Increases the Uptake of Oxidized Low Density Lipoprotein via PPARγ/CD36 Pathway in Inflammatory Adipocytes

Aim: Previous studies have demonstrated that the dysregulated-secretion of adipokines by adipocytes may contribute to obesity-associated atherosclerosis (As) and high density lipoprotein (HDL) may protect against atherogenesis through multiple pathways. This study was to explore the effect of HDL on the oxLDL uptake in inflammatory adipocytes stimulated by endotoxin lipopolysaccharide (LPS) and the possible mechanism. Methods and Results: 3T3-L1 adipocytes were cultured and induced to differentiation and maturation. Acute inflammation in adipocytes was induced by LPS (100 ng/ml) for 6 hours. The adipocytes were pretreated with HDL in various concentrations (10, 50, 100 μg/ml) for 16 hours or with specific PPARγ antagonist (GW9662, 10 μM) or agonist (Rosiglitazone, 10 μM) for 30 min before administration of LPS. The results showed that LPS significantly increased the release of inflammation-related adipokines, such as monocyte chemoattractant protein-1 (MCP-1), plasminogen activator inhibitor 1 (PAI-1), tumor necrosis factor-alpha (TNF-α), interleukin (IL)-8 and IL-6, while decreasing the release of leptin and adiponectin. Meanwhile, LPS reduced the uptake and degradation of 125I-oxLDL, and down-regulated the expression of PPARγ and CD36. Pretreatment with HDL dose-dependently affected the release of IL-8 and IL-6 and the reduced uptake and degradation of oxLDL of adipocytes stimulated by LPS, accompanied with marked upregulation of PPARγ and CD36 expression. Pretreatment with GW9662 markedly inhibited the upregulation of CD36 expression mediated by HDL (100 μg/ml), while the effects of Rosiglitazone were opposite to GW9662. Conclusions: HDL may increase oxLDL uptake of inflammatory adipocytes stimulated by LPS via upregulation of PPARγ/CD36 pathway, which may be a new mechanism of anti-atherosclerosis mediated by HDL