Dependence of IPMSM Motor Efficiency on Parameter Estimates

The efficiency of an IPMSM motor is influenced by the operating point of the machine. Conventional approaches to generate measured efficiency maps may be too expensive to use in some situations, thus it often replaced by simpler variants based on parametric models. A promising approach is to combine model-based approaches with online parameter identification methods which would allow following changes of the parameters. However, such approaches may also result in deteriorated performance if the online parameter estimation is inaccurate. We present a systematic experimental study of the influence of the parameter estimates on the efficiency of a 4.5 kW IPMSM drive and analyze the sources of inaccuracy. The first outcome of this study is that none of the tested methods performs well when the machine is fully loaded, which deteriorates overall performance. The second outcome is that the conventional maximum torque per ampere/current (MTPA/MTPC) is not an accurate optimization criterion. The overall performance of the compared methods thus heavily depends on the testing profile. When a significant part of the profile is at full load, the methods based on online estimation are unsuitable and parameters estimated offline using frequency domain provides better efficiency under the maximum torque per current control strategy.

Unsteady Steam turbine optimization using high fidelity CFD

This paper presents the computational methodology, and experimental investigations accomplished to enhance the efficiency of a turbine stage by applying non-axisymmetric profiling on the rotor hub wall. The experimental setup was a two-stage axial turbine, which was tested at “LISA” test facility at ETH Zurich. The goal was to optimize the interaction of the cavity leakage flow with the rotor passage flow to increase efficiency. The computational optimization was completed using a Genetic Algorithm coupled with an Artificial Neural Network. Unsteady time-accurate simulations were performed, using in-house developed “MULTI3” solver. Besides implementing all geometrical details from the experimental setup into the computational model, it was learned that the unsteady upstream effect could not be neglected. A novel approach was introduced by using unsteady inlet boundary conditions to consider the multistage effect while reducing the computational cost to half. Comprehensive steady and unsteady measurements were performed utilizing pneumatic, Fast Response Aerodynamic (FRAP), and Fast Response Entropy (FENT) probes, on the baseline and profiled test cases. The end-wall profiling was found to be successful in weakening the strength of the hub passage vortex by a 19% reduction in the under-over turning. As a result, the blockage was reduced near the hub region leading to more uniform mass flow distribution along the span. Furthermore, the improvements were confirmed by reductions in entropy, Secondary Kinetic Energy, and pressure unsteadiness. The accurate computational implementations led to an excellent agreement between the predicted and measured efficiency gain.

Nature Inspired MIMO Antenna System for Future mmWave Technologies

In this work, a new Multiple Input Multiple Output (MIMO) antenna system with a novel shape inspired by nature is proposed for Fifth-Generation (5G) communication systems. The antenna is designed on a Rogers 5880. The dielectric constant of the substrate is 2.2, and the loss tangent is assumed to be 0.0009. The gain of the system for the desired bandwidth is nearly 8 dB. The simulated and the measured efficiency of the proposed system is 95% and 80%, respectively. To demonstrate the capability of the system as a potential candidate for future 5G communication devices, MIMO key performance parameters such as the Envelope Correlation Coefficient (ECC) and Diversity Gain (DG) are computed. It is found that the proposed system has low ECC, constant DG, and high efficiency for the desired bandwidth.

Spin-encoded Wavelength-space Multitasking Janus Metasurfaces

The fruitful progress toward light manipulation in reflective (R) or transmissive (T) geometry (half-space) has facilitated strong aspiration to achieving full-space electromagnetic wave control in both R and T channels. Although it promises large-capacity and integrated functionality, yet imposes prohibitive difficulty and big challenging for extreme wave control (direction of arrival in full space) via an ultrathin flat device. As of today, very limited demonstrations were reported for single-band and linear-polarization operation, significantly limiting the exploitable degree of freedoms (DoFs) for real-world applications. Herein, we report for the first time a triple-layer wavelength-space multitasking scheme for wide-angle and large-capacity detection. Two anisotropic sub-meta-atoms are engineered with high quality factor and simultaneous in-plane and out-of-plane symmetry breaking, facilitating four R and two T spin-conversion channels with high efficiency and insulation. The chirality-assisted Fano effect gives rise to the wide-angle operation and boosted channels. Above features and released DoF would be extraordinary beneficial for large-capability and angle-engineered advanced device. Two proof-of-concept metadevices, i.e., large-scanning kaleidoscopic-beam generator and a wide-angle large-capacity reverser for multi-target tracking, are devised to verify the significance. Numerical and experimental results have approved predesigned advanced functions at six channels with measured efficiency over 75%. Our findings in multi-DoF multitasking of metasurfaces could stimulate great interest in radar applications with versatile beam generation and multi-channel integration.

Dosimetry and Calorimetry Performance of a Scientific CMOS Camera for Environmental Monitoring

This paper explores the prospect of CMOS devices to assay lead in drinking water, using calorimetry. Lead occurs together with traces of radioisotopes, e.g., 210Pb, producing γ-emissions with energies ranging from 10 keV to several 100 keV when they decay; this range is detectable in silicon sensors. In this paper we test a CMOS camera (Oxford Instruments Neo 5.5) for its general performance as a detector of X-rays and low energy γ-rays and assess its sensitivity relative to the World Health Organization upper limit on lead in drinking water. Energies from 6 keV to 60 keV are examined. The CMOS camera has a linear energy response over this range and its energy resolution is for the most part slightly better than 2%. The Neo sCMOS is not sensitive to X-rays with energies below ∼10 keV. The smallest detectable rate is 40±3mHz, corresponding to an incident activity on the chip of 7±4Bq. The estimation of the incident activity sensitivity from the detected activity relies on geometric acceptance and the measured efficiency vs. energy. We report the efficiency measurement, which is 0.08(2)% (0.0011(2)%) at 26.3keV (59.5keV). Taking calorimetric information into account we measure a minimal detectable rate of 4±1mHz (1.5±1mHz) for 26.3keV (59.5keV) γ-rays, which corresponds to an incident activity of 1.0±6Bq (57±33Bq). Toy Monte Carlo and Geant4 simulations agree with these results. These results show this CMOS sensor is well-suited as a γ- and X-ray detector with sensitivity at the few to 100 ppb level for 210Pb in a sample.

Utilizing Electronic Medical Records to Standardize Handoffs in Academic Ophthalmology

Purpose Formalized handoff procedures have been shown to increase patient safety and quality of care across multiple medical and surgical specialties,1–4 but literature regarding handoffs in ophthalmology remains sparse. We instituted a standardized handoff utilizing an electronic medical record (EMR) system to improve care for patients shared by multiple resident physicians across weekday, weeknight, and weekend duty shifts. We measured efficiency, efficacy, and resident satisfaction before and after the standardized handoff was implemented. Methods Resident physicians surveyed were primarily responsible for patient care on consult and call services at two quaternary academic medical centers in a major metropolitan area. Patient care was performed in outpatient, emergency, and inpatient settings. Annual anonymous questionnaires consisting of 6 questions were used to collect pre- and postintervention impressions of the standardized EMR handoff process from ophthalmology resident physicians (9 per year; 3 preintervention years and 1 postintervention year). An additional anonymous postintervention questionnaire consisting of 12 questions was used to further characterize resident response to the newly implemented handoff procedure. Results Prior to implementation of a standardized EMR-based handoff procedure, residents unanimously reported incomplete, infrequently updated handoff reports that did not include important clinical and/or psychosocial information. Following implementation, residents reported a statistically significant increase in completeness and timeliness of handoff reports. Additionally, resident perception of EMR handoff utility, efficiency, and usability were comprehensively favorable. Residents reported handoffs only added a mean of 6.5 minutes to a typical duty shift. Conclusion Implementation of our protocol dramatically improved resident perceptions of the handoff process at our institution. Improvements included increased quality, ease-of-use, and efficiency. Our standardized EMR-based handoff procedure may be of use to other ambulatory-based services.

Computing spatial distribution of tube and louvre luminaires efficiency from their description

Lighting computation requires photometry data that are not always available. Lacking photometry data limits lighting study to in situ measurement, luminaire measurement or use of similar luminaire photometry. This is not satisfactory, neither for convenience nor cost and accuracy reasons. Fitting the spatial distribution of luminaire efficiency to their description would allow lighting computations in this kind of situation. An efficiency spatial distribution model is proposed for grid and louvre tube luminaires, taking optic width, louvre between-axis and gloss as parameters. It is constructed over 12 measured efficiency spatial distributions and the corresponding luminaire descriptors. Even if optic and louvre gloss cannot be differentiated, this model fits to measurements and allows for computed irradiance close to experiments within −5% to +19%. In addition, luminaire descriptors can freely vary inside their experimental range and even be extrapolated.

Noise and turn-taking impact postanesthesia care unit handoff efficiency

Background Optimal handoffs are pivotal for patient safety, yet some of the underlying communication mechanisms which support effective handoffs remain to be understood. As handoffs are conversations between providers, understanding communication mechanisms is necessary to improve handoff protocol development. The objective of this study was to characterize communication variables influencing the efficiency of handoffs in the postanesthesia care unit. Methods We conducted a single-center, observational study of handoffs over a three-week period in June/July of 2017. We recorded 96 handoffs between the cardiac operating room and postanesthesia care unit. We defined and measured efficiency by dividing the count of unique, nonrepetitive pieces of information by duration of the handoff conversation. Furthermore, we calculated and measured two communication variables: turn-taking and noise. We utilized West and Zimmerman’s Syntactic Scale to analyze turn taking by segregating noise into three subcategories: environmental noise caused by equipment, environmental noise caused by staff, and third-party interruptions. Finally, we recorded and measured the frequency and duration of noise and turn-taking during the handoff events. Results Due to technical issues, we transcribed and analyzed a total of 85 observations. Providers passed an average of 31.68 unique pieces of information during each handoff with the average length being 1 min and 46 s. Overlaps was the most common type of turn-taking behavior. Activity noise was the most common type of noise. Activity noise took place an average of 3.64 times per handoff and lasted an average of 9.83 s. Turn-taking accounted for 15.6% of variance in handoff efficiency. Together, noise and turn-taking accounted for 25.2% of the variance in handoff efficiency. Conclusion Because turn-taking and noise account for over a quarter the variance in handoff efficiency, recommendations include providing quiet locations for handoffs to take place. Additionally, we recommend that receivers provide input in any handoff interventional studies as their involvement would decrease the need to interrupt or clarify information from the sender.

Seasonal performance estimation of thin film photovoltaic technology

The performance of photovoltaic (PV) module in the environment can be improved by considering the seasonal effects. In this paper, the effect of seasonal variations of Amorphous-Silicon/thin film photovoltaic technology in different seasons has been presented for National Institute of Solar Energy (NISE), Gurgaon site in India. It has been observed that, the estimation efficiency and output power of a-Si technology using module temperature is well match to measured efficiency and output power. This study is mainly very important in India because of the each season’s variation effect on different PV technology will be useful for large scale project assessment.