10,199 research outputs found

    Efficacy of Different Pet Treat Formulations to Prevent Infestation by the Mite Tyrophagus putrescentiae

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    The pet food industry is a major part of the high-value processed food market in the USA and worldwide. Pest control associated with pet foods is an important activity. The mite Tyrophagus putrescentiae is a prolific cosmopolitan species that can infests high-value pet treats undetected until the infestations increase to very large numbers. Propylene glycol is a food-safe additive used to prevent mite infestations (Zhang et al., 2018; Abbar et al. 2015). Unfortunately, propylene glycol in certain foods can harm pets, and many companies are changing formulations. Here we conducted forced infestation of mites on three experimental pet treats and compared these to the current product that contains propylene glycol for susceptibility to mite infestation. We confirmed that the current product with propylene glycol did not support any mite population growth after a forced infestation with 20 mites. Two of the test formulations showed promise in preventing mite infestation, but one formulation was clearly susceptible to mites

    Measurements of noise in Josephson-effect mixers

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    We present new heterodyne receiver results obtained at 100 GHz using resistively-shunted Nb and NbN tunnel junctions. In addition, we have carried out accurate measurements of the available noise power of these devices at the L-band (1.5 GHz) IF frequency. Both the heterodyne and the output noise measurements show that the noise of these devices can be a factor of five or more higher than that predicted by the simple current-biased RSJ model. The noise approaches the appropriate thermal or thermal and shot noise limits for bias voltages where the nonlinearity is not strong (i.e., V>ICRN), but as expected from the RSJ model, can be significantly higher at the low voltages where the mixers are typically biased. The bias voltage dependence of the noise shows structure which is associated with resonances in the RF embedding circuit. Surprisingly, we find that changes in the high-frequency (100 GHz) impedance presented to the junction can dramatically affect the magnitude and voltage dependence of the low-frequency (1.5 GHz) noise. This emphasizes the necessity of very closely matching the junction to free space over a wide frequency range

    An innovative approach to enhancing continuing education activities for practising pharmacists using clicker technology

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    OBJECTIVE The objective of this study was to evaluate the use of an audience response system (i.e. clickers) as an engaging tool for learning and examine its potential for enhancing continuing education (CE) activities. METHODS Attendees at a symposium were invited to utilise and evaluate the use of clickers. Electronic data relating to participant demographics and feedback were collected using clickers during the symposium. RESULTS The 60 attendees who used the clickers were mostly pharmacists (76%) who worked in hospital pharmacy practice (86%). Attendees strongly agreed or agreed that clickers were easy to use (94%), enhanced interaction (98%), allowed comparison of knowledge with that of their peers (78%), brought to attention their knowledge deficits (64%) and should be used again (94%). CONCLUSION The innovative use of clickers at the symposium was very well received by all attendees and offered a number of benefits, including the ability to provide a more engaging and interactive CE activity.Luke E. Grzeskowiak, Josephine To, Alicia E. Thomas and Adam J. Phillip

    Enhancing education activities for health care trainees and professionals using audience response systems: a systematic review

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    Introduction: This review examines the effect of incorporating clickers within practice-based education sessions on educational outcomes of health care trainees and professionals. Methods: A systematic literature review was conducted on primary research studies published up until August 2014. Studies were identified by database searching (Ovid MEDLINE, EMBASE, CINAHL, Scopus, Web of Science, and PsychInfo), citation searching, and reference list checking. Studies were restricted to those evaluating the use of clickers as part of the provision of postgraduate education or continuing education programs and were evaluated according to Kirkpatrick's four levels of training evaluation (reaction, learning, behavior, and results). Results: Seventeen studies met the eligibility criteria. Twelve studies assessed learner and/or speaker reactions, with feedback overwhelmingly positive in all studies. Reported learner benefits included increased attentiveness, engagement, and enjoyment of presentations. Speakers reported that using clickers engaged the audience and assisted in assessing audience comprehension. Eight studies assessed learning outcomes. Higher level evidence obtained from four randomized studies demonstrated significant improvements in knowledge with the use of clickers compared with traditional didactic presentations, but no differences when clickers were compared with an interactive lecture with integrated questions. No studies adequately assessed higher level educational outcomes (behavior and results). Conclusion: Although the use of clickers improves learning environment and learner satisfaction, the limited high-quality data for improvements in learning and behavior outcomes make it uncertain whether the acceptance and implementation of clickers within routine practice-based education programs are warranted at this stage.Luke E. Grzeskowiak, Alice E. Thomas, Josephine To, Adam J. Phillips, Emily Reev

    Performance Measurement of a Multi-Level/Analog Ferroelectric Memory Device Design

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    Increasing the memory density and utilizing the unique characteristics of ferroelectric devices is important in making ferroelectric memory devices more desirable to the consumer. This paper describes the characterization of a design that allows multiple levels to be stored in a ferroelectric based memory cell. It can be used to store multiple bits or analog values in a high speed nonvolatile memory. The design utilizes the hysteresis characteristic of ferroelectric transistors to store an analog value in the memory cell. The design also compensates for the decay of the polarization of the ferroelectric material over time. This is done by utilizing a pair of ferroelectric transistors to store the data. One transistor is used a reference to determinethe amount of decay that has occurred since the pair was programmed. The second transistor stores the analog value as a polarization value between zero and saturated. The design allows digital data to be stored as multiple bits in each memory cell. The number of bits per cell that can be stored will vary with the decay rate of the ferroelectric transistors and the repeatability of polarization between transistors. This paper presents measurements of an actual prototype memory cell. This prototype is not a complete implementation of a device, but instead, a prototype of the storage and retrieval portion of an actual device. The performance of this prototype is presented with the projected performance of the overall device. This memory design will be useful because it allows higher memory density, compensates for the environmental and ferroelectric aging processes, allows analog values to be directly stored in memory, compensates for the thermal and radiation environments associated with space operations, and relies only on existing technologies

    Ferroelectric Field-Effect Transistor Differential Amplifier Circuit Analysis

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    There has been considerable research investigating the Ferroelectric Field-Effect Transistor (FeFET) in memory circuits. However, very little research has been performed in applying the FeFET to analog circuits. This paper investigates the use of FeFETs in a common analog circuit, the differential amplifier. The two input Metal-Oxide-Semiconductor (MOS) transistors in a general MOS differential amplifier circuit are replaced with FeFETs. Resistors are used in place of the other three MOS transistors. The FeFET model used in the analysis has been previously reported and was based on experimental device data. Because of the FeFET hysteresis, the FeFET differential amplifier has four different operating modes depending on whether the FeFETs are positively or negatively polarized. The FeFET differential amplifier operation in the different modes was analyzed by calculating the amplifier voltage transfer and gain characteristics shown in figures 2 through 5. Comparisons were made between the FeFET differential amplifier and the standard MOS differential amplifier. Possible applications and benefits of the FeFET differential amplifier are discussed

    The elimination of surface cross-hatch from relaxed, limited-area Si1 – xGex buffer layers

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    The influence of lateral dimensions on the relaxation and surface topography of linearly graded Si1 – xGex buffer layers has been investigated. A dramatic change in the relaxation mechanism has been observed for depositions on Si mesa pillars of lateral dimensions 10 µm and below. Misfit dislocations are able to extend unhindered and terminate at the edges of the growth zone, yielding a surface free of cross-hatch. For lateral dimensions in excess of 10 µm orthogonal misfit interactions occur and relaxation is dominated by the modified Frank–Read (MFR) mechanism. The stress fields associated with the MFR dislocation pile-ups result in a pronounced cross-hatch topography
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