The Advanced Automated Directional Solidification Furnace

The Advanced Automated Directional Solidification Furnace (AADSF) is a five zone tubular furnace designed for Bridgman-Stockbarger, other techniques of crystal growth involving multiple temperature zones such as vapor transport experiments and other materials science experiments. The five zones are primarily designed to produce uniform hot and cold temperature regions separated by an adiabatic region constructed of a heat extraction plate and an insert to reduce radiation from the hot to the cold zone. The hot and cold zone temperatures are designed to reach 1600 C and 1100 C, respectively. AADSF operates on a Multi-Purpose Experiment Support Structure (MPESS) within the cargo bay of the Space Shuttle on the United States Microgravity Payload (USMP) missions. Two successful flights, both employing the directional solidification or Bridgman Stockbarger technique for crystal growth have been made, and crystals of HgCdTe and PbSnTe grown in microgravity have been produced on USMP-2 and USMP-3, respectively. The addition of a Sample Exchange Mechanism (SEM) will enable three different samples to be processed on future flights including the USMP-4 mission

Nudging allows direct evaluation of coupled climate models with in situ observations: a case study from the MOSAiC expedition

Comparing the output of general circulation models to observations is essential for assessing and improving the quality of models. While numerical weather prediction models are routinely assessed against a large array of observations, comparing climate models and observations usually requires long time series to build robust statistics. Here, we show that by nudging the large-scale atmospheric circulation in coupled climate models, model output can be compared to local observations for individual days. We illustrate this for three climate models during a period in April 2020 when a warm air intrusion reached the MOSAiC (Multidisciplinary drifting Observatory for the Study of Arctic Climate) expedition in the central Arctic. Radiosondes, cloud remote sensing and surface flux observations from the MOSAiC expedition serve as reference observations. The climate models AWI-CM1/ECHAM and AWI-CM3/IFS miss the diurnal cycle of surface temperature in spring, likely because both models assume the snowpack on ice to have a uniform temperature. CAM6, a model that uses three layers to represent snow temperature, represents the diurnal cycle more realistically. During a cold and dry period with pervasive thin mixed-phase clouds, AWI-CM1/ECHAM only produces partial cloud cover and overestimates downwelling shortwave radiation at the surface. AWI-CM3/IFS produces a closed cloud cover but misses cloud liquid water. Our results show that nudging the large-scale circulation to the observed state allows a meaningful comparison of climate model output even to short-term observational campaigns. We suggest that nudging can simplify and accelerate the pathway from observations to climate model improvements and substantially extends the range of observations suitable for model evaluation.</p

Bounded and compact multipliers between Bergman and Hardy spaces

This paper studies the boundedness and compactness of the coefficient multiplier operators between various Bergman spaces A p and Hardy spaces H q . Some new characterizations of the multipliers between the spaces with exponents 1 or 2 are derived which, in particular, imply a Bergman space analogue of the Paley-Rudin Theorem on sparse sequences. Hardy and Bergman spaces are shown to be linked using mixed-norm spaces, and this linkage is used to improve a known result on ( A p , A 2 ), 1< p <2.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/42949/1/20_2005_Article_BF01225524.pd

Cosmic ray oriented performance studies for the JEM-EUSO first level trigger

JEM-EUSO is a space mission designed to investigate Ultra-High Energy Cosmic Rays and Neutrinos (E > 5 ⋅ 1019 eV) from the International Space Station (ISS). Looking down from above its wide angle telescope is able to observe their air showers and collect such data from a very wide area. Highly specific trigger algorithms are needed to drastically reduce the data load in the presence of both atmospheric and human activity related background light, yet retain the rare cosmic ray events recorded in the telescope. We report the performance in offline testing of the first level trigger algorithm on data from JEM-EUSO prototypes and laboratory measurements observing different light sources: data taken during a high altitude balloon flight over Canada, laser pulses observed from the ground traversing the real atmosphere, and model landscapes reproducing realistic aspect ratios and light conditions as would be seen from the ISS itself. The first level trigger logic successfully kept the trigger rate within the permissible bounds when challenged with artificially produced as well as naturally encountered night sky background fluctuations and while retaining events with general air-shower characteristics

Mi niño con asma : Hispanic/Latina Mothers, Environmental Justice, And Photovoice At The Front Lines Of The Asthma Epidemic

Asthma is an important environmental justice concern for first generation Mexican-Americans. Families experience disparities in housing conditions, access to care, and legal marginalization. Little is known about how Hispanic/Latina mothers of children with asthma navigate these oppressions. Problem: The purpose of this paper is to describe the discourses of environmental justice of a group Hispanic/Latina caregivers of children with asthma. Method: A photovoice design was used with Hispanic/Latina mothers (n=11) in Tacoma, Washington, to take, discuss, select and display phototexts to policymakers that communicated their experiences and opinions in managing asthma for their child. Using critical narrative analysis, phototexts were analyzed for the use of agency and structure in confronting environmental threats to asthma. Results: Participants produced 33 phototexts taking on the roles of teacher, parent, advocate, investigator, and storyteller. Narratives identified environmental threats (breathable, meteorological, medical, social, emotional, and ingestible) and promoted protective actions and social advocacy against such threats. Conclusion: Mothers\u27 actions as teachers and advocates in the phototexts provided opportunities for promoting empowerment and solidarity with others in the face of multiple environmental oppressions. Critical narrative analysis of photo-texts provided an opportunity to identify important opportunities for furthering environmental justice in new immigrant groups

Design, Control and Performance of RiceWrist: A Force Feedback Wrist Exoskeleton for Rehabilitation and Training

This paper presents the design, control, and performance of a high fidelity four degree-of-freedom wrist exoskeleton robot, RiceWrist, for training and rehabilitation. The RiceWrist is intended to provide kinesthetic feedback during the training of motor skills or rehabilitation of reaching movements. Motivation for such applications is based on findings that show robot-assisted physical therapy aids in the rehabilitation process following neurological injuries. The exoskeleton device accommodates forearm supination and pronation, wrist flexion and extension, and radial and ulnar deviation in a compact parallel mechanism design with low friction, zero backlash, and high stiffness. As compared to other exoskeleton devices, the RiceWrist allows easy measurement of human joint angles and independent kinesthetic feedback to individual human joints. In this paper, joint-space as well as task-space position controllers and an impedance-based force controller for the device are presented. The kinematic performance of the device is characterized in terms of its workspace, singularities, manipulability, backlash, and backdrivability. The dynamic performance of RiceWrist is characterized in terms of motor torque output, joint friction, step responses, behavior under closed loop set-point and trajectory tracking control, and display of virtual walls. The device is singularity-free, encompasses most of the natural workspace of the human joints, and exhibits low friction, zero-backlash, and high manipulability, which are kinematic properties that characterize a high-quality impedance display device. In addition, the device displays fast, accurate response under position control that matches human actuation bandwidth, and the capability to display sufficiently hard contact with little coupling between controlled degrees-of-freedom