Directional motion of dielectric droplets on polymer-coated conductor driven by electric corona discharge

Achieving better control of liquid droplet movement is an important subject for academic research and industrial applications. In this study, we investigate the use of electric corona discharge to drive and control oil droplet movement. For a fully covered polymer-coated copper plate, all droplets on the surface were found to move outward in the same direction. Interestingly, for a polymer coating a hole directly beneath a needle biased with a high DC voltage, we observed the existence of a zone boundary at which all of the droplets within the boundary move inward, whereas droplets outside the boundary move outward. The boundary appeared to depend on the hole size and the voltage bias. Our model simulations reasonably agree well with the experimental measurements of these peculiar phenomena

Integrative analysis of non-targeted metabolome and transcriptome reveals the mechanism of volatile formation in pepper fruit

Introduction: Aroma is a key inherent quality attributes of pepper fruit, yet the underlying mechanisms of aroma compound biosynthesis remain unclear.Methods: In this study, the volatile profile of the QH (cultivated Capsicum chinense) and WH (cultivated Capsicum annuum) pepper varieties were putatively identified during fruit development using gas chromatography-mass spectrometry (GC-MS).Results and discussion: The results identified 203 volatiles in pepper, and most of the esters, terpenes, aldehydes and alcohols were significantly down-regulated with fruit ripening. The comparison of volatile components between varieties revealed that aldehydes and alcohols were highly expressed in the WH fruit, while esters and terpenes with fruity or floral aroma were generally highly accumulated in the QH fruit, providing QH with a fruity odor. Transcriptome analysis demonstrated the close relationship between the synthesis of volatiles and the fatty acid and terpene metabolic pathways, and the high expression of the ADH, AAT and TPS genes was key in determining the accumulation of volatiles in pepper fruit. Furthermore, integrative metabolome and transcriptome analysis revealed that 208 differentially expressed genes were highly correlated with 114 volatiles, and the transcription factors of bHLH, MYB, ARF and IAA were identified as fundamental for the regulation of volatile synthesis in pepper fruit. Our results extend the understanding of the synthesis and accumulation of volatiles in pepper fruit

Direct observation of precipitation along twin boundaries and dissolution in a magnesium alloy annealing at high temperature

Precipitation along twin boundaries and dissolution in a cold-rolled Mg-Y-Nd alloy was directly observed for the first time during annealing at 490 °C. Precipitation occurred concurrently with recrystallization and the combined effect of precipitation and solute segregated to twin boundaries modified the recrystallization behaviour. Precipitates later dissolved into the matrix at the point where full recrystallization was nearly complete. The precipitates and higher solute concentration along original twin boundaries hindered grain growth of newly formed recrystallized grains. Even where twin boundaries had been consumed by recrystallization, the size of recrystallized grains were still controlled by the pre-existing twin boundaries

Atomic structure of Mg-based metallic glasses from molecular dynamics and neutron diffraction

We use a combination of classical molecular dynamics simulation and neutron diffraction to identify the atomic structure of five different Mg–Zn–Ca bulk metallic glasses, covering a range of compositions with substantially different behaviour when implanted in vitro. There is very good agreement between the structures obtained from computer simulation and those found experimentally. Bond lengths and the total correlation function do not change significantly with composition. The zinc and calcium bonding shows differences between composition: the distribution of Zn–Ca bond lengths becomes narrower with increasing Zn content, and the preference for Zn and Ca to avoid bonding to themselves or each other becomes less strong, and, for Zn–Ca, transforms into a positive preference to bond to each other. This transition occurs at about the same Zn content at which the behaviour on implantation changes, hinting at a possible structural connection. A very broad distribution of Voronoi polyhedra are also found, and this distribution broadens with increasing Zn content. The efficient cluster packing model, which is often used to describe the structure of bulk metallic glasses, was found not to describe these systems well

Single-machine batch scheduling under time-of-use tariffs: New mixed-integer programming approaches

International audienceTime-of-use (TOU) pricing has been implemented by many electricity suppliers to alleviate the peak load of power grid, which provides a good opportunity for industrial consumers to reduce their energy bills. In industrial enterprises that involve batch processing machines, energy expenditure often accounts for large portion of the final product cost. Optimizing batch scheduling under TOU tariffs in these enterprises will be of great significance. This study investigates a single machine batch scheduling problem under TOU tariffs. The objective is to minimize the total electricity cost by optimally scheduling all jobs within a given planning horizon. Two mixed integer linear programming (MILP) models, which are respectively based on time-index formulation and time-interval formulation, are developed for the problem. The models are solved by CPLEX. Computational results on randomly generated instances demonstrate the effectiveness of the proposed approaches

Bi-criteria single-machine batch scheduling with machine on/off switching under time-of-use tariffs

International audienceThe industrial sector is the largest consumer of the world's total energy and most of its consumption is in form of electricity. In recent years, to strengthen the peak load regulation capability, time-of-use (TOU) pricing has been implemented in many countries to encourage consumers to shift their use from peak to mid- and off-peak periods such that their energy bills can be reduced. In this paper, we study a new single-machine batch scheduling problem with machine on/off switching under TOU tariffs, which aims to simultaneously minimize total electricity cost and makespan. For the problem, we first develop a bi-objective mixed-integer linear programming model. Based on optimal batch rule analysis, an improved model is further provided which greatly reduces Pareto optimal solution search space. To efficiently solve large-size problems, we propose a heuristic based ε-constraint method. The results from extensive computational experiments confirm the effectiveness and efficiency of the proposed model and the algorithm

Directional motion of dielectric droplets on polymer-coated conductor driven by electric corona discharge

Achieving better control of liquid droplet movement is an important subject for academic research and industrial applications. In this study, we investigate the use of electric corona discharge to drive and control oil droplet movement. For a fully covered polymer-coated copper plate, all droplets on the surface were found to move outward in the same direction. Interestingly, for a polymer coating a hole directly beneath a needle biased with a high DC voltage, we observed the existence of a zone boundary at which all of the droplets within the boundary move inward, whereas droplets outside the boundary move outward. The boundary appeared to depend on the hole size and the voltage bias. Our model simulations reasonably agree well with the experimental measurements of these peculiar phenomena