Hybrid Long-Period Fiber Grating with Multimode Fiber Core for Refractive Index Measurement

A refractive index （RI） sensor based on hybrid long-period fiber grating （LPFG） with multimode fiber core （MMFC） is proposed and demonstrated. The surrounding RI can be determined by monitoring the separation between the resonant wavelengths of the LPFG and MMFC since the resonant wavelengths of the LPFG and MMFC will shift in opposite directions when the surrounding RI changes. Experimental results show that the sensor possesses an enhanced sensitivity of 526.92nm/RIU in the RI range of 1.387-1.394 RIU. The response to the temperature is also discussed.

Emergency department operations and management education in emergency medicine training

BACKGROUND:This study was undertaken to examine the current level of operations and management education within US-based Emergency Medicine Residency programs.METHODS:Residency program directors at all US-based Emergency Medicine Residency programs were anonymously surveyed via a web-based instrument.Participants indicated their levels of residency education dedicated to documentation,billing/coding,core measure/quality indicator compliance,and operations management.Data were analyzed using descriptive statistics for the ordinal data/Likert scales.RESULTS:One hundred and six(106)program directors completed the study instrument of one hundred and fifty-six(156)programs(70%).Of these,82.6%indicated emergency department(ED)operations and management education within the training curriculum.Dedicated documentation training was noted in all but 1 program(99%).Program educational offerings also included billing/coding(83%),core measure/quality indicators(78%)and operations management training(71%).In all areas,the most common means of educating came through didactic sessions and direct attending feedback or 69%-94%and 72%-98%respectively.Residency leadership was most confident with resident understanding of quality documentation(80%)and less so with core measures(72%),billing/coding/RVUs(58%),and operations management tools(23%).CONCLUSIONS:While most EM residency programs integrate basic operational education related to documentation and billing/coding,a smaller number provide focused education on the dayto-day management and operations of the ED.Residency leadership perceives graduating resident understanding of operational management tools to be limited.All respondents value further resident curriculum development of ED operations and management.

Novel and Simple Calorimetric Methods for Quantifying Losses in Magnetic Core and GaN Transistor in a High Frequency Boost Converter

In design and implementation of a boost converter,information on loss characteristics of switching devices and magnetic materials is a prerequisite,especially in high frequency applications.To gather such information,testing and accurate loss quantification is needed.Previous methods for measuring magnetic core loss are either only suitable for sinusoidal wave excitations or cannot separate winding loss from inductor loss.In addition,existing loss measurement approaches on the newly introduced GaN transistors are not satisfactory.In this paper,we present a new method to distinguish winding loss from inductor loss under practical excitations.This method utilizes a converter to generate the actual excitation waveforms and uses a calorimetric setup to quantify the losses.By splitting up the inductor in a converter into an air-core inductor and a magnetic-core inductor,both equipped with exactly the same winding structure,the air-core inductor loss can be used as the reference of the magnetic-core inductor winding loss.In this way,losses in the magnetic core can be determined in the actual operating condition of a converter in which the inductor is to be used.Moreover,a simple calorimetric approach for obtaining loss information of GaN transistors are is also presented.Both methods require simple setup and are easy and convenient to execute.The methods work well in assessing different high frequency magnetic core materials and measuring losses in GaN transistors at 1MHz.