7,475 research outputs found

    Microkelvin thermometry with Bose-Einstein condensates of magnons and applications to studies of the AB interface in superfluid 3^3He

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    Coherent precession of trapped Bose-Einstein condensates of magnons is a sensitive probe for magnetic relaxation processes in superfluid 3He-B down to the lowest achievable temperatures. We use the dependence of the relaxation rate on the density of thermal quasiparticles to implement thermometry in 3He-B at temperatures below 300 μ\muK. Unlike popular vibrating wire or quartz tuning fork based thermometers, magnon condensates allow for contactless temperature measurement and make possible an independent in situ determination of the residual zero-temperature relaxation provided by the radiation damping. We use this magnon-condensate-based thermometry to study the thermal impedance of the interface between A and B phases of superfluid 3He. The magnon condensate is also a sensitive probe of the orbital order-parameter texture. This has allowed us to observe for the first time the non-thermal signature of the annihilation of two AB interfaces.Comment: 26 pages, 7 figures, manuscript prepared for EU Microkelvin Collaboration Workshop 2013. Accepted for publication in Journal of Low Temperature Physic

    Taking the bait: Species taking oral rabies vaccine baits intended for raccoons

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    Raccoon rabies in eastern USA is managed by strategically distributing oral rabies vaccine (ORV) baits. The attractiveness, palativity, density, and non-target species bait take affect ORV effectiveness. We examined raccoon and non-target species differences in investigating/removing fish-meal polymer and coated sachet baits applied to simulate two aerial bait distribution densities. Bait densities of 150 baits/km2 and 75 baits/km2 were evaluated, respectively, in zones expected to have high and low Racc oon densities. Three primary non-target species visited baits: coyotes, white-tailed deer, and feral swine. The proportion of bait stations visited by raccoons during 1 week observation periods ranged from 50 to 70%, exceeding non-target species visitation. Raccoon take rates for visited baits averaged from 59 to 100%. Raccoon visitation was similar for both bait densities, indicating a proportionally greater quantity of baits were taken in the higher bait density zone. Coyote visitation rates ranged from 16 to 26%, with take rates for visited baits between 46 and 100%. Coyotes were expected to take baits intended for raccoons, because similar baits are applied to vaccinate coyotes. Deer regularly investigated but rarely took baits. Feral swine were in low abundance in the high bait density zone (higher human density) and visited ≤ 1% of baits there but visited baits at frequencies similar to coyotes and deer in the low-density zone and were likely to take encountered baits (63–100%). Non-target bait consumption could be a concern in some circumstances for achieving sufficient raccoon sero-conversion rates

    Taking the bait: species taking oral rabies vaccine baits intended for raccoons

    Get PDF
    Raccoon rabies in eastern USA is managed by strategically distributing oral rabies vaccine (ORV) baits. The attractiveness, palativity, density, and non-target species bait take affect ORV effectiveness. We examined raccoon and non-target species differences in investigating/removing fish-meal polymer and coated sachet baits applied to simulate two aerial bait distribution densities. Bait densities of 150 baits/km2 and 75 baits/km2 were evaluated, respectively, in zones expected to have high and low raccoon densities. Three primary non-target species visited baits: coyotes, white-tailed deer, and feral swine. The proportion of bait stations visited by raccoons during 1 week observation periods ranged from 50 to 70%, exceeding non-target species visitation. Raccoon take rates for visited baits averaged from 59 to 100%. Raccoon visitation was similar for both bait densities, indicating a proportionally greater quantity of baits were taken in the higher bait density zone. Coyote visitation rates ranged from 16 to 26%, with take rates for visited baits between 46 and 100%. Coyotes were expected to take baits intended for raccoons, because similar baits are applied to vaccinate coyotes. Deer regularly investigated but rarely took baits. Feral swine were in low abundance in the high bait density zone (higher human density) and visited ≤ 1% of baits there but visited baits at frequencies similar to coyotes and deer in the low-density zone and were likely to take encountered baits (63–100%). Non-target bait consumption could be a concern in some circumstances for achieving sufficient raccoon sero-conversion rates

    Taking the bait: Species taking oral rabies vaccine baits intended for raccoons

    Get PDF
    Raccoon rabies in eastern USA is managed by strategically distributing oral rabies vaccine (ORV) baits. The attractiveness, palativity, density, and non-target species bait take affect ORV effectiveness. We examined raccoon and non-target species differences in investigating/removing fish-meal polymer and coated sachet baits applied to simulate two aerial bait distribution densities. Bait densities of 150 baits/km2 and 75 baits/km2 were evaluated, respectively, in zones expected to have high and low Racc oon densities. Three primary non-target species visited baits: coyotes, white-tailed deer, and feral swine. The proportion of bait stations visited by raccoons during 1 week observation periods ranged from 50 to 70%, exceeding non-target species visitation. Raccoon take rates for visited baits averaged from 59 to 100%. Raccoon visitation was similar for both bait densities, indicating a proportionally greater quantity of baits were taken in the higher bait density zone. Coyote visitation rates ranged from 16 to 26%, with take rates for visited baits between 46 and 100%. Coyotes were expected to take baits intended for raccoons, because similar baits are applied to vaccinate coyotes. Deer regularly investigated but rarely took baits. Feral swine were in low abundance in the high bait density zone (higher human density) and visited ≤ 1% of baits there but visited baits at frequencies similar to coyotes and deer in the low-density zone and were likely to take encountered baits (63–100%). Non-target bait consumption could be a concern in some circumstances for achieving sufficient raccoon sero-conversion rates

    Anti-Racist Considerations for Teaching CACREP Assessment and Diagnosis Courses

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    Professional counselors must act as anti-racist social justice advocates throughout the counseling relationship, including assessment, diagnosis, and treatment planning. Due to internalized racism and inappropriate instruments, assessment and diagnosis are two critical areas where marginalized populations have historically experienced misdiagnosis and pathologizing impacting overall client care and wellbeing. Inappropriate instruments, inadequate training, and counselor bias have profound impacts on access to treatment and resources for individuals holding marginalized racial identities. Although the call for anti-racist counseling is clear, the profession is still unclear on how to teach these concepts to counselor trainees. Counselor educators must be intentional about incorporating anti-racist concepts into all counseling courses including assessment and diagnosis. Situated by the historical context of racism within helping professions, we aim to provide practical teaching implications for infusing anti-racist content into assessment and diagnosis courses in counselor education

    Orbital damping of the oscillating superfluid He A-B interface at low temperatures

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    We present a model for the friction and effective mass of an oscillating superfluid He A-B interface due to orbital viscosity in the B-phase texture close to the interface. The model is applied to an experiment in which the A-B interface was stabilised in a magnetic field gradient at the transition field mT at 0 bar pressure and at a very low temperature mK. The interface was then oscillated by applying a small additional field at frequencies in the range 0.1-100 Hz. The response of the interface is governed by friction and by its effective mass. The measured dissipation does not fit theoretical predictions based either on the Andreev scattering of thermal quasiparticles or by pair-breaking from the moving interface. We describe a new mechanism based on the redistribution of thermal quasiparticle excitations in the B-phase texture engendered by the moving interface. This gives rise to friction via orbital viscosity and generates a significant effective mass of the interface. We have incorporated this mechanism into a simple preliminary model which provides reasonable agreement with the measured behaviour

    The Effect of Electronic Cigarette User Modifications and E-liquid Adulteration on the Particle Size Profile of an Aerosolized Product

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    Electronic cigarettes (e-cigarettes) are an alternate nicotine delivery system that generate a condensation aerosol to be inhaled by the user. The size of the droplets formed in the aerosol can vary and contributes to drug deposition and ultimate bioavailability in the lung. The growing popularity of e-cigarette products has caused an increase in internet sources promoting the use of drugs other than nicotine (DOTNs) in e-cigarettes. The purpose of this study was to determine the effect of various e-cigarette and e-liquid modifications, such as coil resistance, battery voltage, and glycol and drug formulation, on the aerosol particle size. E-liquids containing 12 mg/mL nicotine prepared in glycol compositions of 100% propylene glycol (PG), 100% vegetable glycerin (VG), or 50:50 PG:VG were aerosolized at three voltages and three coil resistances. Methamphetamine and methadone e-liquids were prepared at 60 mg/mL in 50:50 PG:VG and all e-liquids were aerosolized onto a 10 stage Micro-Orifice Uniform Deposit Impactor. Glycol deposition correlated with drug deposition, and the majority of particles centered between 0.172–0.5 μm in diameter, representing pulmonary deposition. The 100% PG e-liquid produced the largest aerosol particles and the 100% VG and 50:50 PG:VG e-liquids produced ultra-fine particles \u3c0.3 μm. The presence of ultrafine particles indicates that drugs can be aerosolized and reach the pulmonary alveolar regions, highlighting a potential for abuse and risk of overdose with DOTNs aerosolized in an e-cigarette system

    Turbulent drag on a low-frequency vibrating grid in superfluid He-4 at very low temperatures

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    We present measurements of the dissipative turbulent drag on a vibrating grid in superfluid He-4 over a wide range of (low) frequencies. At high velocities, the dissipative drag is independent of frequency and is approximately the same as that measured in normal liquid He-4. We present measurements on a similar grid in superfluid He-3-B at low temperatures which shows an almost identical turbulent drag coefficient at low frequencies. However, the turbulent drag in He-3-B is substantially higher at higher frequencies. We also present measurements of the inertial drag coefficient for grid turbulence in He-4. The inertial drag coefficient is significantly reduced by turbulence in both superfluid and normal liquid He-4
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