356 research outputs found
The incentive properties of different forms of urban transport financing and regulation
Trial lecture held 26 October 2012 before the defence for the PhD in Logistics at Molde University College - Specialized University in Logistic
Applications of signal transduction and xerophytophysiology by exposing hypocotyls in organic peanut production
The AnM practices in peanut production included three steps. The three letters, A, n and M, showed the shapes of the section-cross of the ridge at the three steps of different growth stages of the peanut crop. First, the peanut seeds were sown a little deeper than usual, about 8 cm, in the ridge to induce the extra-elongation of the hypocotyl. When the seeds were sown, the cross-section of the ridge looked like the letter “A”. The second, the hypocotyls elongated more than usual were exposed to light and dry air by removing the soil away around the young seedlings just after the emergence. At this time, the cross-section of the ridge looked like the letter “n”. The third, at the middle growth stages, soils on the both sides of ridge were earthed up to welcome the late pegs. At this time, the cross-section of the ridge looked like the letter “M”. Physiologically, the AnM technique induced osmotic adjustment, which improved photosynthetic activities by maintaining a higher leaf turgor potential. Anthocyanin accumulation was observed visually in hypocotyls of the young seedlings soon after the hypocotyl exposure started. The anthocyanin accumulation is accompanied by accumulations of soluble sugars, soluble proteins. All the consequences of the xerophytophysiological responses collaborated together to make the crop healthier through their individual function in plant growth and development. Gdi-15 (Groundnut desiccation induced) gene is a stress-responsive gene in peanut plant and its up-regulation expression was found in hypocotyl. In overall, hypocotyl exposure as a stimulation did induce the up-expression of the drought responsive gene, Gdi-15, and the consequent osmotic adjustment and anthocyanin accumulation but caused no damage to the whole plant. The AnM practice was more effective in the soil with compost applied to the surface layer and therefore it is feasible in organic peanut production
Pore-scale fluid flow simulation coupling lattice Boltzmann method and pore network model
The lattice Boltzmann method and pore network model are two types of the most popular pore-scale fluid flow simulation methods. As a direct numerical simulation method, lattice Boltzmann method simulates fluid flow directly in the realistic porous structures, characterized by high computational accuracy but low efficiency. On the contrary, pore network model simulates fluid flow in simplified regular pore networks of the real porous media, which is more computationally efficient, but fails to capture the detailed pore structures and flow processes. In past few years, significant efforts have been devoted to couple lattice Boltzmann method and pore network model to simulate fluid flow in porous media, aiming to combine the accuracy of lattice Boltzmann method and efficiency of pore network model. In this mini-review, the recent advances in pore-scale fluid flow simulation methods coupling lattice Boltzmann method and pore network model are summarized, in terms of single-phase flow, quasi-static two-phase drainage flow and dynamic two-phase flow in porous media, demonstrating that coupling the lattice Boltzmann method and pore network model offers a promising and effective approach for addressing the up-scaling problem of flow in porous media.Cited as: Zhao, J., Liu, Y., Qin, F., Fei, L. Pore-scale fluid flow simulation coupling lattice Boltzmann method and pore network model. Capillarity, 2023, 7(3): 41-46. https://doi.org/10.46690/capi.2023.06.0
A Data-Driven Condition Monitoring of Product Quality Analysis System Based on RS and AHP
Mechanical and electrical products have complex structure and intelligent control system, their reliability plays an important role in the normal operation of security facilities. However, most manufacturers usually pay more attention to the product designing and manufacturing quality, with little interest in the intelligent fault diagnosis. The objective of this study is to develop the products quality intelligent analysis and management system based on Rough Set (RS) and Analytic Hierarchy Process (AHP). Firstly, this paper reviews the principle of hardware, software design, monitoring platform and quality analysis system to reduce the number of information transfer with computer technology. Secondly, the fault types and feature extractions of different faults of elevators are presented and simplified by using RS theory. Then, the objective weight of level index model can be obtained by AHP method, and the comprehensive analysis weight of each index is obtained by using the value of subjective and objective weight coefficients with the golden ratio. Finally, a comprehensive decision weight of the major index for quality control analysis system of many vertical elevators is presented. The results show that the data-driven condition monitoring and quality analysis system is a kind of important means to prevent a disaster of complex mechanical and electrical products
The welfare effects of nationalization in a mixed duopoly public transport market
Recently, many cities have launched new rail transit lines. Once these new rail transit lines start commercial operation, they will play important roles as competitors to conventional bus services. In this paper, the effects of nationalization on equilibria have been studied in a mixed duopoly public transport market, in which one publicly-owned rail transit operator competes with one private bus operator. Two numerical case studies show the nationalization of a rail transit company is always socially desirable both in Bertrand pricing game in the short run and in Nash non-cooperative game in the long run
Design of overvoltage suppression filter based on high-frequency modeling of cable in SiC based motor drive
SiC-based motor drives have the advantages of achieving higher efficiency and higher power density than traditional Si-based motor drives, and are gradually being widely used in electric power transmission. Due to different application situations such as oil field and airplane, a long cable is applied between the motor drive and three-phase motor and the distance may exceed hundreds of meters, which will cause serious voltage reflection problem, damaging working life of the motor. Meanwhile, the high slew rate of output voltage created by SiC-based motor drive deteriorates this phenomenon. In order to solve this problem, we first analyze the principle and influencing factors of voltage reflection, and establish the equivalent circuit model of the long cable. Then we put forward design method of LRC passive filter to suppress voltage reflection, and give simulation analysis. At last we built an experimental platform to verify the effectiveness of the LRC passive filter in SiC-based motor drive, and the experimental results show that the LRC passive filter with optimized parameters has good suppression effect of voltage reflection
Droplet evaporation in finite-size systems: Theoretical analysis and mesoscopic modeling
The classical D^{2}-Law states that the square of the droplet diameter decreases linearly with time during its evaporation process, i.e., D^{2} (t) = D^{2}_{0} - Kt, where D_{0} is the droplet initial diameter and K is the evaporation constant. Though the law has been widely verified by experiments, considerable deviations are observed in many cases. In this work, a revised theoretical analysis of the single droplet evaporation in finite-size open systems is presented for both two-dimensional (2D) and 3D cases. Our analysis shows that the classical D^{2}-Law is only applicable for 3D large systems (L ≫ D_{0}), L is the system size), while significant deviations occur for small (L ≤ 5D_{0}) and/or 2D systems. Theoretical solution for the temperature field is also derived. Moreover, we discuss in detail the proper numerical implementation of droplet evaporation in finite-size open systems by the mesoscopic lattice Boltzmann method (LBM). Taking into consideration shrinkage effects and an adaptive pressure boundary condition, droplet evaporation in finite-size 2D/3D systems with density ratio up to 328 within a wide parameter range (K = [0.003, 0.18] in lattice units) is simulated, and remarkable agreement with the theoretical solution is achieved, in contrast to previous simulations. The present work provides insights into realistic droplet evaporation phenomena and their numerical modeling using diffuse-interface methods.
Biventricular Pacing Cardiac Contractility Modulation Improves Cardiac Contractile Function via Upregulating SERCA2 and miR-133 in a Rabbit Model of Congestive Heart Failure
Development of the Family Poverty Index (FPI): A Novel Index to Measure Socioeconomic Status
The CANDLE Study aims to uncover factors experienced during pregnancy and early life that affect cognition, behavior, and health of children. External stressors and socioeconomic status (SES) influence the fetus through “prenatal programming”. However, comprehensive measures of SES do not exist, except those based on income and education.
We selected 53 variables from the CANDLE study including annual household income, headcount, marital status, health insurance, parental occupation and education. Singular value decomposition imputation (SVDI), a principal components analysis approach unaffected by the 24.4% missing data in our variables, was applied to all 53 variables (Troyanskaya, 2001).
All variables were distilled into 3 principal components explaining 93% of the variability. These components were combined to develop the Family Poverty Index (FPI, range 1-10). All subjects were separated into deciles based on FPI scores. Individuals with FPI=1 were the “poorest” with 79% individuals having annual incomes \u3c55,000. With FPI=1-3, 95% had Medicaid insurance and 4.8% had employer/private insurance, whereas with FPI=8-10, 86% had employer/private insurance and 11.8% had Medicaid. Other variables showed similar distributions across FPI categories.
FPI appears to be a robust measure of SES in the CANDLE Study population. Further research should test the validity of the FPI in other datasets
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Projected near-term changes of temperature extremes in Europe and China under different aerosol emissions
This study assesses near-term future changes in temperature extremes over China and Europe in scenarios with two very different anthropogenic aerosol (AA) pathways from 2016 to 2049: a maximum technically feasible aerosol reduction (MTFR), and a current legislation aerosol scenario (CLE), both with greenhouses gas forcing following RCP 4.5. Simulations with a fully coupled atmosphere-ocean model HadGEM3-GC2 show that there is an increase in hot extremes and a decrease in cold extremes relative to the present day (1995-2014) over China and Europe in both scenarios. However, the magnitude of the changes in both hot and cold extremes depends strongly on the AA pathway. The AA reduction in MTFR amplifies the changes in temperature extremes relative to CLE, and accounts for 40% and 30% of the projected changes in temperature extremes relative to present day over China and Europe respectively. Thus, this study suggests that future and current policy decisions about AA emissions have the potential for a large near-term impact on temperature extremes
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