Polyphase drive systems configuration aiming EMI mitigation

Topologies of motor drive systems are studied, aiming the reduction of common-mode (CM) currents. Initially, the aspects concerning the CM currents circulation are analysed. The reason of common-mode voltages generation, the circulating paths for the resulting CM currents and their effects are discussed. Then, a non-conventional drive system configuration is proposed in order to reduce the CM currents and their effects. This configuration comprehends a non-conventional inverter module wired to a motor with an unusual connection. The cables arrangement differs from the standard solution, too. The proposed topology is compared with other ones, like the active circuit for common-mode voltages compensation. The contribution of the configuration to the reduction of CM voltages and currents and their related interferences are evaluated, based on numerical simulations. Some results are presented and discussed regarding the suitability of the proposed configuration as a potential solution to reduce the CM currents effects, when the state of art and implementation cost of drives are taken into account.

A redescription of a common euryhaline cumacean from southern Brazil: Diastylis sympterygiae Bacescu & Queiroz, 1985 (Crustacea: Cumacea)

Diastylis sympterygiae Bacescu & Queiroz (1985) has been reported in many ecological studies conducted in the Patos Lagoon, southern Brazil. However, the original description of this species is based on damaged specimens from stomach contents of rays, and therefore insufficient for a confident identification. In the present contribution, based on a large number of well-preserved specimens now available from the type locality area, the description of this common euryhaline species is completed and its range of distribution as far north as Sao Paulo is extended.

Mapping of angular leaf spot resistance QTL in common bean (Phaseolus vulgaris L.) under different environments

Background: Common bean (Phaseolus vulgaris L.) is the most important grain legume for human diet worldwide and the angular leaf spot (ALS) is one of the most devastating diseases of this crop, leading to yield losses as high as 80%. In an attempt to breed resistant cultivars, it is important to first understand the inheritance mode of resistance and to develop tools that could be used in assisted breeding. Therefore, the aim of this study was to identify quantitative trait loci (QTL) controlling resistance to ALS under natural infection conditions in the field and under inoculated conditions in the greenhouse. Results: QTL analyses were made using phenotypic data from 346 recombinant inbreed lines from the IAC-UNA x CAL 143 cross, gathered in three experiments, two of which were conducted in the field in different seasons and one in the greenhouse. Joint composite interval mapping analysis of QTL x environment interaction was performed. In all, seven QTLs were mapped on five linkage groups. Most of them, with the exception of two, were significant in all experiments. Among these, ALS10.1(DG,UC) presented major effects (R-2 between 16% - 22%). This QTL was found linked to the GATS11b marker of linkage group B10, which was consistently amplified across a set of common bean lines and was associated with the resistance. Four new QTLs were identified. Between them the ALS5.2 showed an important effect (9.4%) under inoculated conditions in the greenhouse. ALS4.2 was another major QTL, under natural infection in the field, explaining 10.8% of the variability for resistance reaction. The other QTLs showed minor effects on resistance. Conclusions: The results indicated a quantitative inheritance pattern of ALS resistance in the common bean line CAL 143. QTL x environment interactions were observed. Moreover, the major QTL identified on linkage group B10 could be important for bean breeding, as it was stable in all the environments. Thereby, the GATS11b marker is a potential tool for marker assisted selection for ALS resistance.