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Green waste compost (GWC) is a value-added product generated by the composting of urban green waste. Although GWC could potentially be used as a growth medium for soilless culture of plants, GWC alone has high salinity, high pH, and other undesirable physicochemical properties. In the current study, we therefore assessed how addition of vermiculite (VMT: 0, 3.5, and 7%) and humic acid (HA: 0, 0.5, and 1 g/100 g) affected the physicochemical properties of GWC and its use as a growth medium for cornflower (Centaurea cyanus L.). GWC modified by the combination of 3.5% VMT and 0.5 g/100 g HA had the best physicochemical properties (bulk density, porosity, water holding capacity, electrical conductivity, pH, and nutrient content) and resulted in the best growth of cornflower in terms of plant height, maximum root length, flower number, and biomass. The results therefore indicate that GWC modified by 3.5% VMT and 0.5 g/100 g HA powder is an excellent soilless growth medium.

Induction motors are widely used as the workhorses for the petroleum and chemical industry. As such, their efficiency is an important issue for both the users and manufacturers. As currently designated by IEC (International Electrotechnical Commission) [1], the efficiency of induction motors is classified by four levels: standard (IE1), high (IE2), premium (IE3), and super premium (IE4) efficiency. Line Start Permanent Magnet Synchronous Motor (LSPMSM) has been researched and designed to meet the IE4 standard. With the equivalent circuit analysis and Finite Element Analysis (FEA), the starting and steady-state running performance have been scrutinized. To verify the design model and the feasibility of reaching super premium efficiency level, two 4-pole LSPMSM prototypes were built and tested. Compared with Premium Efficiency Induction Motors (PEIM) with the same ratings, the prototypes yielded better performances including efficiency, power factor, temperature rise, etc., over a wide output power range. The design considerations, test results, and the comparison with the equivalent induction motors are presented in this paper.

This paper presents the numerical simulation of flow-thermal coupling for 2 MW Doubly-Fed Induction Wind Generator (DFIG). With fundamental assumptions and corresponding boundary conditions, the number of grid is reduced to save calculation time. The temperature of internal air for different cooling system configuration is calculated with commercial FEA software FLUENT without assumption. Four cooling system configurations of DFIG are presented, analyzed and compared in details. The best cooling system configuration of DFIG has been found and will be used into our DFIG production.