Design optimization of a synchronous reluctance motor based on operating cycle

Synchronous reluctance motors are becoming an interesting solution for drives applications requiring high efficiency. The design of those machines is normally based on the optimization of the motor performance at the rated working point in terms of torque production, torque ripple and efficiency, but in many applications the drive will operate for most of the time at partial load and frequent overload may be required, with a speed not necessarily equal to the rated value. In this work we propose an optimized machine design method to maximize the drive efficiency on the total operating cycle, considering a specific speed and torque profile. Four typical working points are selected, each of them maintained by the machine for a different time in the operating cycle. The obtained machine is compared with the one optimized based on the rated conditions only, showing slightly higher losses on a single working point but an improved efficiency on the global operating cycle

Exploring the Relationship Between Covert Narcissism and Amorality: The Mediating Influences of Self-efficacy and Psychological Entitlement

Narcissism, as a personality construct, has attracted attention from countless scholars across multiple disciplines. It has been suggested that two forms of narcissism exist (Wink, 1991) and research has supported the delineation of overt (grandiose) and covert (hypersensitive) narcissism (Dickinson & Pincus, 2003; Gabbard, 2009; Luchner, Houston, Walker, & Houston, 2011). To date, most of the research devoted to narcissism has been focused on the overt rather than the covert form (Cain, Pincus, & Ansell, 2008). Further, researchers propose that a decreased level of meaningful relational interactions among narcissists may result in a higher propensity for amoral behaviors. Thus, to extend the research the current study explores the influence of several mediating variables on the relationship between covert narcissism and amorality. The current study found a negative relationship between covert narcissism and self-efficacy as well as an anticipated positive relationship between covert narcissism and psychological entitlement. It was also observed that self-efficacy and psychological entitlement did partially mediate the relationship between covert narcissism and higher amorality, supporting the study’s predictions

Can Organizational Practices Inadvertently Silence Potential Whistleblowers?

This study examines how employee perceptions of organizational ethics, safety practices, and manager-subordinate relationships might influence employees’ silence in regards to workplace hazards using a sample of 178 workers in the mining, manufacturing, and petrochemical industries. The findings support a model in which employee perceptions of endangerment by their organization and fear of retaliation for whistleblowing mediate the relationship between manager-subordinate relationships and the practice of withholding negative (and sometimes vital) information from organizational management. Results suggest that even with high quality superior/subordinate relationships, employees may still withhold important information due to the overall perception of the current safety climate

The journey travelled – A view of two settings a decade apart

Inclusion is generally recognized as an ongoing, active process which reflects shifts in policies, practice and values as well as political choices made over long periods of time. Although intended as a transformative concept it can also represent a messy compromise between congealed policy positions and contradictory practices. Against this background of compromise and dissatisfaction, this study aims to examine how two schools with clear inclusive aspirations and intentions have weathered the last decade. Drawing upon two research visits ten years apart in which the schools were filmed and members of the school community were interviewed, this study reports on their perception of the journey travelled. Data from the study shows that in both cases there was a shift away from practices which were previously seen as being a route towards greater inclusion. The causes for these shifts were political, economic and social factors underpinned by the pervasive influence of the special education and medical model on the two schools’ practice and principles

In situ sprayed bioresponsive immunotherapeutic gel for post-surgical cancer treatment

Cancer recurrence after surgical resection remains a significant cause of treatment failure. Here, we have developed an in situ formed immunotherapeutic bioresponsive gel that controls both local tumour recurrence after surgery and development of distant tumours. Briefly, calcium carbonate nanoparticles pre-loaded with the anti-CD47 antibody are encapsulated in the fibrin gel and scavenge H+ in the surgical wound, allowing polarization of tumour-associated macrophages to the M1-like phenotype. The released anti-CD47 antibody blocks the ‘don’t eat me’ signal in cancer cells, thereby increasing phagocytosis of cancer cells by macrophages. Macrophages can promote effective antigen presentation and initiate T cell mediated immune responses that control tumour growth. Our findings indicate that the immunotherapeutic fibrin gel ‘awakens’ the host innate and adaptive immune systems to inhibit both local tumour recurrence post surgery and potential metastatic spread

Investigation of material combinations for axially-laminated synchronous machine

Abstract High-speed electric machines are special types of electric machines which aim for compact, direct-driven high-speed applications and highly efficient operation, especially, when gearbox can be avoided. Design of these types of machines is highly iterative combining multiphysics optimization and leads to custom types of machines which fulfill the application-specific requirements. Synchronous Reluctance Machines (Syn-RMs) might have an axially-laminated solid rotor structure, which combines magnetic and non-magnetic layers rigidly bonded to each other by vacuum brazing, hot isostatic pressing, soldering, explosion welding or even by additive manufacturing. In the study five non-magnetic materials and nine magnetic materials are cross compared and the results show clear differences in performance, efficiency and physical properties of the rotor when made of different material combinations, and thereby can suggest the best pairs when application-specific performance criteria are known. The study is carried out on a 12 kW machine with a maximum speed of 24000 rpm

Sample preparation method for metal(loid) contaminant quantitation in rodent hair collected in Yuma County, Arizona

Yuma County, Arizona, is a large agricultural hub of the USA located in the southwestern corner of Arizona on the USA-Mexico border. Year-round use of agrichemicals at a massive scale along with the influx of aquatic contaminants in the Colorado River led to significant levels of environmental pollution and hence exposure risks for people and wildlife. Although hair is a recognized biomarker for metal exposure, there is no universal hair preparation protocol. This study evaluated two digestion methods for metal quantitation using inductively coupled plasma-mass spectrometry (ICP-MS) and three methods for mercury quantitation using cold vapor-atomic absorption spectroscopy (CV-AAS), both employing certified reference materials. The “overnight” and “heating” digestion methods were suitable for ICP-MS, while only the heating method was suitable for CV-AAS. These validated methods will be useful for a variety of human and wildlife assessments of toxic metal(loid) exposure.Flinn FoundationOpen access articleThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]