Ryerson University

About: Ryerson University is a education organization based out in Toronto, Ontario, Canada. It is known for research contribution in the topics: Population & Poison control. The organization has 7671 authors who have published 20164 publications receiving 394976 citations. The organization is also known as: Ryerson Polytechnical Institute & Ryerson Institute of Technology.

DC-Link Current Minimization for High-Power Current-Source Motor Drives

Abstract: In this paper, a loss reduction and DC-link current minimization strategy for a high-power current-source inverter (CSI) fed drive is proposed. The proposed strategy consists of an inverter maximum modulation index control scheme and a flux optimization algorithm. Specifically, in the inverter modulation index control, the CSI modulation index is kept at the maximum value while the current-source rectifier (CSR) is used to regulate a reduced variable DC-link current, and therefore, to control the motor current magnitude. This control scheme can effectively reduce the DC-link current, and at the same time, improve the line-side and motor-side waveforms. On the other hand, for the optimized flux control, the relationship between the rotor flux and the DC-link current is first investigated thoroughly. Based on this analysis, the DC-link current from the maximum inverter modulation index control can be minimized further by optimizing the rotor flux according to system variables such as the motor speed, the applied torque, and the motor-side capacitor size. With the proposed dc current minimization strategy, the losses in the semiconductor devices and the DC-link can be reduced, and the drive current rating could be lowered. Both simulation and experimental results on a 4.16-kV 600-hp CSI-fed drive system are obtained to verify the effectiveness of the proposed strategy.

The Influence of Physical Body Traits and Masculinity on Anal Sex Roles in Gay and Bisexual Men

Abstract: Sociological, psychological, and public health studies document that many gay and bisexual men may self-label by their anal penetrative role (i.e., bottom or exclusively receptive; top or exclusively insertive; or versatile, both receptive and insertive during anal intercourse). Yet, what orients men to think of themselves as tops, bottoms or versatiles is poorly understood. We surveyed 429 men engaging in same-sex anal intercourse to investigate the degree to which anal penetrative self-identity was concordant with actual penetrative behavior. Additionally, the roles of masculinity and physical body traits (e.g., penis size, muscularity, height, hairiness, and weight) were tested as correlates of anal penetrative identity and identity-behavior concordance. Tops and bottoms showed a high degree of concordance between identity and enacted behavior; however, only half of versatiles reported concordant identity and behavior (i.e., wanting to be versatile and actually reporting versatile behavior). Generally, tops reported larger penises than bottoms. They also reported being comparatively more masculine than bottoms. Versatiles fell somewhat between the tops and bottoms on these traits. Of the six independent variables, penis size and masculinity were the only two factors to influence concordance or discordance between identity and penetrative behavior. Our study suggests that the correlates of gay men’s sexual self-labels may depend on objective traits in addition to the subjective pleasure associated with receptive or insertive anal intercourse.

Accuracy improvement of SOC estimation in lithium-ion batteries

Abstract: Scheduling Lithium-Ion batteries for energy storage applications in power systems requires an accurate estimate of their state of charge (SOC). The Coulomb counting method is popular in the industry but remains inaccurate. This paper presents an intelligent technique for the SOC estimation in Lithium-Ion batteries. The model is developed offline using adaptive neuro-fuzzy inference systems (ANFIS). It considers the cell nonlinear characteristics, as supplied by the manufacturer, which provide the relationship between the cell SOC and open-circuit voltage (OCV) at different temperatures. The manufacturer data are used to model the cell characteristics by ANFIS in order to yield the cell SOC at any arbitrary OCV and temperature within the given range. The pack SOC is accordingly estimated. For the purposes of comparison, the Coulomb counting method is used at the cell level, rather than the pack level, to estimate the SOC of the battery. Laboratory experiments are conducted on a 5.3 kWh battery module where measured SOC is compared to Coulomb counting computations at the cell and pack levels. Results show distinct superiority for the proposed ANFIS technique over the traditional Coulomb counting method.

The utilization of recycled concrete aggregate to produce controlled low-strength materials without using Portland cement

Abstract: This paper reports the results of an experimental study that investigated the feasibility of using fine and coarse recycled concrete aggregate (RCA) with slag or fly ash to produce Controlled Low-Strength Materials (CLSM). The main objective was to produce CLSM using only recycled and by-product materials without the need to add Portland cement. In addition to the hydraulic activity of slag and high-calcium fly ash (HCFA), their pozzolanic reaction was activated by the alkalis and calcium hydroxide present in the residual paste of the RCA. Preliminary tests showed mixtures with slag to have 7-day compressive strengths 70% higher than mixtures with fly ash. Two types of CLSM with slag were investigated in further detail: one with fine and the other with fine/coarse RCA. The results showed that the developed CLSMs are suitable for a wide range of applications particularly those requiring structural support and fast hardening.