Efficient sorting of free electron orbital angular momentum

We propose a method for sorting electrons by orbital angular momentum (OAM). Several methods now exist to prepare electron wavefunctions in OAM states, but no technique has been developed for efficient, parallel measurement of pure and mixed electron OAM states. The proposed technique draws inspiration from the recent demonstration of the sorting of OAM through modal transformation. We show that the same transformation can be performed on electrons with electrostatic optical elements. Specifically, we show that a charged needle and an array of electrodes perform the transformation and phase correction necessary to sort OAM states. This device may enable the analysis of the spatial mode distribution of inelastically scattered electrons

The Efficacy of a Key Word Signing Workshop

This study examined the effect of a 1-day, 6-hour key word signing (KWS) workshop on in-service special education teachers’ and speech-language pathologists’ (SLPs) (a) skill identifying American Sign Language (ASL) signs; (b) skill producing ASL signs; (c) use of KWS in the classroom or therapy room; and (d) perceived changes from taking part in a KWS workshop. Participants included five special education teachers, three SLPs, and four students with complex communication needs (aged 3 to 14 years) participated in the study. All eight adult participants participated in a pretest-posttest design with repeated posttest measures over time, survey design, and phenomenological research to examine the effect of a KWS workshop on their skill identifying and producing manual signs as well as their perceived changes from taking part in the KWS workshop. Three of the eight adult participants and four students participated in an A-B single-case design, which was used to determine the effect of the KWS workshop on the in-service staff’s use of KWS in their classrooms or therapy rooms. The adult participants demonstrated an immediate increase in their ability to identify and produce the ASL signs taught during the KWS workshop, and they exhibited an increasing trend over the six postworkshop assessment sessions (across 11 or 12 weeks) in their ASL sign identification and production skills. The adult participants’ percentage of nonoverlapping data (PND) for the number of signed utterances, signs, and different signs they used in their classrooms or therapy rooms indicated a large effect. Two of the four students did not produce signed utterances during the classroom activities throughout the three preworkshop observations and five postworkshop observations. The PND for one student, who produced signed utterances, suggested a large effect and the PND for the other student, who used signed utterances, suggested a small effect. A majority of the participants reported that students, who relied on AAC and used natural speech, as well as classroom staff increased their production (i.e., imitation and spontaneous production) of ASL signs after the adult participants attended a workshop and began to use KWS in their classrooms and therapy rooms