Modifications to PM-assisted Synchronous Reluctance Machine to Achieve Rare-Earth Free Heavy-duty Traction

Automotive applications require electrical machines designed for high torque density, wide speed range, and low cost. NdFeB magnets can achieve a high torque density and wide speed range, and however, they have a high cost. Therefore, this article explores the capability of rare-earth-free (REF) design through a PM-assisted synchronous reluctance (PM-SynRel) motor. A PM-SynRel design with NdFeB has been used in this study where the NdFeB magnets have been replaced with ferrite magnets. Then, several modifications on the rotor have been made to ensure mechanical safety. Thermal analysis has been conducted last to evaluate the temperatures in the different machine parts to avoid exceeding the required limits. Finally, a prototype has been made and tested to validate the simulation results

Parascedosporium and its relatives: phylogeny and ecological trends

The genus Scedosporium and its relatives comprising microascalean anamorphs with slimy conidia were studied. Graphium and Parascedosporium also belong to this complex, while teleomorphs are found in Pseudallescheria, Petriella, Petriellopsis, and Lophotrichus. Species complexes were clearly resolved by rDNA ITS sequencing. Significantly different ecological trends were observed between resolved species aggregates. The Pseudallescheria and Scedosporium prolificans clades were the only lineages with a marked opportunistic potential to mammals, while Petriella species were associated primarily with soil enriched by, e.g. dung. A consistent association with bark beetles was observed in the Graphium clade. The ex-type strain of Rhinocladium lesnei, CBS 108.10 was incorrectly implicated by Vuillemin (1910) in a case of human mycetoma; its sequence was identical to that of the ex-type strain of Parascedosporium tectonae, CBS 127.84

Barcoding and microcoding using "identiprimers" with Leptographium species

Leptographium species provide an ideal model to test the applications of a PCR microcoding system for differentiating species of other genera of ascomycetes. Leptographium species are closely related and share similar gross morphology. Probes designed for a PhyloChip for Leptographium have been transferred and tested as primers for PCR diagnostic against Leptographium species. The primers were combined with complementary universal primers to identify known and suspected undescribed species of Leptographium. The primer set was optimized for 56 species, including the three varieties of L. wageneri, then blind-tested against 10 random DNA samples. The protocols established in this study successfully identified species from the blind test as well as eight previously undescribed isolates of Leptographium. The undescribed isolates were identified as new species of Leptographium with the aid of the microcoding PCR identification system established in this study. The primers that were positive for each undescribed isolate were used to determine close relatives of these species and some of their biological characteristics. The transfer of oligonucleotides from a micro-array platform to a PCR diagnostic was successful, and the identification system is robust for both known and unknown species of Leptographium. © 2010 by The Mycological Society of America.Articl

Characterisation of synnematous bark beetle-associated fungi from China, including Graphium carbonarium sp. nov.

Ophiostomatoid fungi on trees are typically bark beetle associates that cause sapstain in timber and some are pathogens. Very little is known regarding the ophiostomatoid fungi associated with bark beetles in China and the aim of this study was to identify a collection of these fungi with synnematous anamorphs. Micromorphology and DNA sequences of the internal transcribed spacer regions (ITS) of the ribosomal DNA and the partial β-tubulin gene were used for identifications. The isolates could be divided in six morphological groups. DNA sequence comparisons with published data confirmed that these groups represented six species, four in the Ophiostomatales (Sordariomycetidae) and two in the Microascales (Hypocreomycetidae). The majority of these were isolated from conifer hosts. Ophiostoma quercus, O. setosum, Pesotum fragrans (Ophiostomatales) and Graphium pseudormiticum (Microascales) were found on Tsuga dumosa infested by a Pissodes sp. In addition, O. quercus and P. fragrans were found associated with Tomicus yunnanensis on Pinus yunnanensis, P. fragrans with a Pissodes sp. on P. armandi, and O. piceae with Ips subelongatus on Larix olgensis. Only two species, O. quercus and a new species in the Graphium penicilliodes complex, described here as Graphium carbonarium sp. nov., were isolated from Pissodes galleries on Salix babylonica. These results include several new fungus-host and fungus-insect associations, and G. pseudormiticum is reported here for the first time from China.National Research Foundation (NRF), Department of Science and Technology (DST), members of the Tree Protection Co-operative program (TPCP), Ministry of Science and Technology (MOST) of China for financial support (2007DFA31190

Barcoding and microcoding using “identiprimers” with Leptographium

Leptographium species provide an ideal model to test the applications of a PCR microcoding system for differentiating species of other genera of ascomycetes. Leptographium species are closely related and share similar gross morphology. Probes designed for a PhyloChip for Leptographium have been transferred and tested as primers for PCR diagnostic against Leptographium species. The primers were combined with complementary universal primers to identify known and suspected undescribed species of Leptographium. The primer set was optimized for 56 species, including the three varieties of L. wageneri, then blind-tested against 10 random DNA samples. The protocols established in this study successfully identified species from the blind test as well as eight previously undescribed isolates of Leptographium. The undescribed isolates were identified as new species of Leptographium with the aid of the microcoding PCR identification system established in this study. The primers that were positive for each undescribed isolate were used to determine close relatives of these species and some of their biological characteristics. The transfer of oligonucleotides from a micro-array platform to a PCR diagnostic was successful, and the identification system is robust for both known and unknown species of Leptographium.National Research Foundation, University of Pretoria, Forestry and Agricultural Biotechnology institute (FABI), NRF/DST Centre of Excellence in Tree Health Biotechnology (CTHB

Barcoding and microcoding using "identiprimers" with Leptographium species

Leptographium species provide an ideal model to test the applications of a PCR microcoding system for differentiating species of other genera of ascomycetes. Leptographium species are closely related and share similar gross morphology. Probes designed for a PhyloChip for Leptographium have been transferred and tested as primers for PCR diagnostic against Leptographium species. The primers were combined with complementary universal primers to identify known and suspected undescribed species of Leptographium. The primer set was optimized for 56 species, including the three varieties of L. wageneri, then blind-tested against 10 random DNA samples. The protocols established in this study successfully identified species from the blind test as well as eight previously undescribed isolates of Leptographium. The undescribed isolates were identified as new species of Leptographium with the aid of the microcoding PCR identification system established in this study. The primers that were positive for each undescribed isolate were used to determine close relatives of these species and some of their biological characteristics. The transfer of oligonucleotides from a micro-array platform to a PCR diagnostic was successful, and the identification system is robust for both known and unknown species of Leptographium.National Research Foundation, University of Pretoria, Forestry and Agricultural Biotechnology institute (FABI), NRF/DST Centre of Excellence in Tree Health Biotechnology (CTHB

Enhancing the Torque Density of Conventional PM-SynRel Machine with Hybrid Flux Barrier

Electrical machines with high torque density are required for traction application. Availability of bonded magnets with complex shapes and magnetization pattern can significantly extend the design space of electrical machines. This paper introduces a hybrid flux barriers design to improve the torque density of permanent magnet assisted synchronous reluctance (PM -SynRel) machine using ferrite magnets. The torque density with hybrid flux barriers is found to improve along the entire range of speed compared to the conventional flux barriers. The hybrid barrier design achieves similar performance to that of curved barrier with relatively flat shaped magnets in the last flux barrier. Thus, the hybrid barrier is able to enhance the torque density at a potentially reduced cost of manufacturing. The hybrid flux barrier design is validated for both electromagnetic and mechanical performance using commercial finite element analysis (FEA) packages. © 2019 IEEE

Holistic Design Optimisation of 350 kW High-Speed Permanent Magnet Assisted Synchronous Reluctance Machine for Heavy-Duty Electric Vehicle

The widely adopted “high-speed machine + high-ratio gear” solutions for passenger electric vehicle (EV) drivetrains are yet to be explored for demanding heavy-duty applications. This paper will investigate 350kW level high speed traction motor development based on permanent magnet assisted synchronous reluctance machine (PMaSyRM) topology. With the overall target of boosting active power density under threshold of materials’ performance boundaries, multi-physics solvers are configured by both analytical and simulation tools to tackle design challenges in electromagnetic, mechanical, and thermal domains. To deal with multiple design parameters and performance indicators, a three stage hierarchical development platform is proposed and implemented to feature not only comprehensiveness but also balanced computation resource consumption and accuracy. Apart from globally parametrized machine geometry, the usually pre-defined slot number and pole number are looked into in the first and second stages, respectively, and are down-selected due to their substantial influence on material usage and loss distributions. In the final stage, a novel mechanical stress design concept is proposed, which significantly accelerates the “electromagnetic + mechanical” coupled rotor design process. Moreover, three typical cooling strategies are quantitatively evaluated for further down-selection of the most suitable thermal management. The finalized design is validated by a 1:1 PMaSyRM prototype with 580Nm peak torque, 15000rpm peak speed, which features active power density of 6.3 kW/kg

Discovery of Ophiostoma tsotsi on Eucalyptus wood chips in China

Ophiostoma species such as O. quercus are the most frequent causal agents of sapstain of freshly felled hardwood timber and pulpwood. Many species are regarded as economically important agents of wood degradation. The aim of this study was to identify a collection of Ophiostoma isolates, resembling O. quercus, found on stained Eucalyptus pulpwood chips in China. DNA sequences of the internal transcribed spacer regions, including the 5.8S region, of the ribosomal DNA, and parts of the β-tubulin and elongation factor-1α genes, revealed that the isolates were not O. quercus. Surprisingly, they represented O. tsotsi, a wound-infesting fungus recently described from hardwoods in Africa. In addition, sequence data from an isolate from agarwood in Vietnam, identified in a previous study as belonging to an unknown Pesotum species, were also shown to represent O. tsotsi. A high level of genetic variability was observed among isolates of both O. quercus and O. tsotsi. This was unexpected and suggests that both species have been present in Asia for a significant amount of time.National Research Foundation (NRF), South Africa; members of the Tree Protection Co-operative Programme (TPCP), South Africa; THRIP initiative of the Department of Trade and Industry (DTI), South Africa; Department of Science and Technology (DST), South Africa; Ministry of Science and Technology of China (MOST