Characterization of supercapacitors matrix

This paper treats supercapacitors matrix characterization. In order to cut off transient power peaks and to compensate for the intrinsic limitations in embedded sources, the use of supercapacitors as a storage system is quite suitable, because of their appropriate electrical characteristics (huge capacitance, small series resistance, high specific energy, high specific power), direct storage (energy ready for use), and easy control by power electronic conversion. This use requires supercapacitors modules where several cells connected in serial and/or in parallel, thus a bypass system to balance the charging or the discharging of supercapacitors is required. In the matrix of supercapacitors, six elements of three parallel BCAP0350 supercapacitors in serial connections have been considered. This topology permits to reduce the number of the bypass circuits and it can work in degraded mode. Actually, it allows the system to have more reliability by providing power continually to the load even when there are one or more cells failed. Simulation and experimental results are presented and discussed.     

Microemulsions with Mixed Nonionic Surfactants and Flavor Oil

The microemulsion systems composed of water/sucrose laurate/ethoxylated mono-di-glyceride/peppermint oil were formulated and characterized using electrical conductivity and small-angle X-ray scattering. The solubilization capacity of water in the oil is dependent on the surfactant mixing ratio. A static percolation phenomenon was observed in these systems and the water volume fraction percolation threshold was determined. A progressive transformation of water-in-oil to bicontinuous microemulsions, occurring upon dilution with water was revealed for equal amounts of sucrose laurate and ethoxylated mono-di-glyceride in the microemulsions. The periodicity, that is a characteristic length for the domain size of the microemulsions, increases linearly with the increase in the water volume fraction, whereas the correlation length, that is also a characteristic length for the domain size, increases with the increase in the water volume fraction up to a certain value then decreases.     

Characterization of Water/Sucrose Laurate/n-Propanol/Allylbenzene Microemulsions

Water/n-propanol/sucrose laurate/allylbenzene micellar systems were formulated and applied in the isomerization of allylbenzene in the presence of heterogenized derivatives of some platinum group catalysts. The ratio (w/w) of n-propanol/surfactant studied herewith was 2/1. Temperature insensitive microemulsions were found. The microemulsions were characterized by the volumetric parameters, density, excess volume, ultrasonic velocity, and isentropic compressibility. The densities increase with increases in the water volume fraction. Excess volumes of the microemulsions decrease for water volume fractions below 0.2, level off for water volume fractions between 0.2 and 0.6 then increase for water volume fractions above 0.6. Excess volumes of the studied micellar systems increase with temperature. Isentropic compressibilities increase with temperature for water volume fractions below 0.8 and decrease for water volume fractions above 0.8. Structural transitions from water-in-oil to bicontinuous to oil-in-water occur along the microemulsion phase. The particle hydrodynamic diameter of the oil-in-water microemulsions at the 0.95 water volume fraction was found to decrease with temperature.     

Bacterial indicators of faecal pollution in the waters of the El-Kabir River and Akkar watershed in Syria and Lebanon

Water samples for bacterial analyses were taken, when possible, at 41 sites in Lebanon and Syria in the El‐Kabir River watershed. Samples were analysed for total coliform (TC), faecal coliform (FC) and faecal streptococcus. The Lebanese samples also were analysed for the presence of sulphate‐reducing bacteria. The TC and FC concentrations were extremely high throughout the watershed, rendering the water unfit for any human uses. The origin of the bacteria is the untreated sewage waste from the numerous settlements situated throughout the watershed. This primary origin is supported by high ratios of FC/faecal streptococcus, although impacts from animal wastes also were observed. The bacterial levels were higher in summer than in winter, indicating a high winter river flow that dilutes a relatively constant source of human sewage discharged to the system. Spring waters also exhibited elevated levels of bacteria, implicating surface land use and waste disposal practices upstream of the springs. The data clearly shows that human health is at a high risk and that strategies for improving water quality and protecting spring water must be expeditiously implemented.     

Plant paralog to viral movement protein that potentiates transport of mRNA into the phloem

CmPP16 from Cucurbita maxima was cloned and the protein was shown to possess properties similar to those of viral movement proteins. CmPP16 messenger RNA (mRNA) is present in phloem tissue, whereas protein appears confined to sieve elements (SE). Microinjection and grafting studies revealed that CmPP16 moves from cell to cell, mediates the transport of sense and antisense RNA, and moves together with its mRNA into the SE of scion tissue. CmPP16 possesses the characteristics that are likely required to mediate RNA delivery into the long-distance translocation stream. Thus, RNA may move within the phloem as a component of a plant information superhighway.     

Thermal modeling and heat management of supercapacitor modules for vehicle applications

Temperature has a huge influence on supercapacitor cells and modules ageing. Consequently, thermal management is a key issue concerning lifetime and performance of supercapacitor modules. This paper presents thermal modeling and heat management of supercapacitor modules for vehicle applications. The thermal model developed is based on thermal-electric analogy and allows the determination of supercapacitor temperature. Relying on this model, heat management in supercapacitor modules was studied for vehicle applications. Thus, the modules were submitted to real life driving cycles and the evolution of temperatures of supercapacitors was estimated according to electrical demands. The simulation results show that the hotspot is located in the middle of supercapacitors module and that a forced airflow cooling system is necessary.