Design and Implementation of a Thermoelectric Cooling Solution for a CCD-based NUV Spectrograph

The Colorado Ultraviolet Transit Experiment (CUTE) is a 6U CubeSat designed to obtain transit spectra of more than ten close-orbiting exoplanets. To this end, CUTE houses a near-ultraviolet (~250 – 330 nm) spectrograph based around a novel rectangular Cassegrain telescope; the spectrograph sensor is an off-the-shelf Teledyne e2v CCD. To achieve desired spectral signal-to-noise ratio (SNR), dark current is reduced by cooling the CCD to a temperature of −50 °C with a thermoelectric cooler (TEC). The TEC is driven by a constant current buck converter with an H-bridge topology for bidirectional current control. The packaging of the CCD imposes a maximum time rate of change of temperature of 5 K/min. A cascaded software control loop (discussed here) was developed that constrains this time rate of change within allowable bounds while simultaneously driving the CCD temperature to a desired setpoint. Criteria for sizing a TEC to the application and initial laboratory results are discussed, as well as digital filtering methods employed and possible solutions to integral wind-up

The Colorado Ultraviolet Transit Experiment: The First Dedicated Ultraviolet Exoplanet Mission

The past few years of space mission development have seen an increase in the use of small satellites as platforms for dedicated astrophysical research; they offer unique capabilities for time-domain science and complementary advantages over large shared resource facilities like the Hubble Space Telescope, including: (1) low cost and relatively quick development timelines; (2) observing strategies dedicated to niche but important science questions; and (3) ample opportunity for students and early career scientists and engineers to be involved on the front lines of space mission development. The Colorado Ultraviolet Transit Experiment (CUTE) is a NASA-supported 6U CubeSat assembled and tested at the Laboratory for Atmospheric and Space Physics within the University of Colorado Boulder. It is designed to observe the evolving atmospheres on short-period exoplanets with a dedicated science mission unachievable by current and planned future space missions. CUTE operates with a bandpass of ∼2487 – 3376 Å and an average spectral resolution element of 3.9 Å. The mission launched in September of 2021 and is in the process of conducting transit spectroscopy of approximately one dozen short-period exoplanets during its primary mission. This proceeding describes the overall CUTE satellite program, including the mission development integration and testing, anticipated science return, and lessons learned to improve both universities’ and commercial companies’ ability to create and collaborate on successful academically and research-focused small satellite missions. While CubeSats are becoming increasingly accessible and utilized for scientific research and student education, CUTE serves as an example that university small satellite programs have specific needs to successfully and efficiently achieve both scientific and educational elements. These include (1) a minimum threshold of commercial-off-the-shelf product quality, performance, and support; (2) specific and timely guidelines from launch service providers regarding launch readiness and delivery requirements; (3) and sufficient funding to provide multi-disciplinary engineering and program management support across the developmental life-cycle of the mission

The fourth flight of CHESS: spectral resolution enhancements for high-resolution FUV spectroscopy

In this proceeding, we describe the scientific motivation and technical development of the Colorado Highresolution Echelle Stellar Spectrograph (CHESS), focusing on the hardware advancements and testing of components for the fourth and final launch of the payload (CHESS-4). CHESS is a far ultraviolet rocket-borne instrument designed to study the atomic-to-molecular transitions within translucent cloud regions in the interstellar medium. CHESS is an objective echelle spectrograph, which uses a mechanically-ruled echelle and a powered (f/12.4) cross-dispersing grating; it is designed to achieve a resolving power R > 100,000 over the band pass λλ 1000–1600 Å. CHESS-4 utilizes a 40 mm-diameter cross-strip anode readout microchannel plate detector, fabricated by Sensor Sciences LLC, to achieve high spatial resolution with high global count rate capabilities (∼ MHz). An error in the fabrication of the cross disperser limited the achievable resolution on previous launches of the payload to R ∼ 4000. To remedy this for CHESS-4, we physically stress the echelle grating, introducing a shallow toroidal curvature to the surface of the optic. Preliminary laboratory measurements of the resulting spectrum show a factor of 4–5 improvement to the resolving power. Results from final efficiency and reflectivity measurements for the optical components of CHESS-4 are presented, along with the pre-flight laboratory spectra and calibration results. CHESS-4 launched on 17 April 2018 aboard NASA/University of Colorado Boulder sounding rocket mission 36.333 UG. We present flight results for the observation of the γ Ara sightline

Group 3 ITI Consensus Report: Materials and antiresorptive drug-associated outcomes in implant dentistry

Objectives: The aim of Working Group 3 was to address the influence of both material- and anti-resorptive drug- related factors on clinical and biological outcomes and complications in implant dentistry. Focused questions were addressed on (a) implant materials other than titanium (alloy)s, (b) transmucosal abutment materials and (c) medications affecting bone metabolism were addressed. Materials and Methods: Three systematic reviews formed the basis for discussion in Group 3. Consensus statements and clinical recommendations were formulated by group consensus based on the findings of the systematic reviews. Patient perspectives and recommendations for future research were also conveyed. These were then presented and accepted following further discussion and modifications as required by the plenary. Results: Zirconia is a valid alternative to titanium as material for implant and transmucosal components, allowing soft and hard tissue integration with clinical outcomes— identified by implant survival, marginal bone loss and peri-implant probing depths—up to 5-years comparable to titatnium. However, most of the evidence for zirconia implants is based on 1-piece implants limiting the indication range. Furthermore, based on expert opinion, zirconia transmucosal components might be preferred in the esthetic zone. In patients receiving low-dose bisphosphonate therapy, the rate of early implant failure is not increased, while the long-term effects remain poorly studied. Although it has not been sufficiently addressed, similar outcomes can be expected with low-dose denosumab. A drug holiday is not recommended when considering implant placement in patients treated with low-dose ARD. However, the specific therapeutic window, the cumulative dose and the administration time should be considered. Access to peri-implant supportive care is mandatory to prevent periimplantitis-related medication-related osteonecrosis of the jaw (MRONJ) or implantrelated sequestra (IRS). In patients receiving low-dose anti-resorptive drugs (ARD) therapy, the risk of complications related to implant placement is high, and implant procedures in this specific population should be strictly treated in a comprehensive multidisciplinary center. Finally, healthy dental implants should not be removed before low or high-dose ARD. Conclusions: Zirconia implants can be an alternative to titanium implants in selected indications. However, the current state of evidence remains limited, especially for 2- piece implant designs. Administration of low-dose ARD did not show any negative impact on early implant outcomes, but careful follow-up and supportive care is recommended in order to prevent peri-implant MRONJ and IRS. Implant placement in high-dose patients must be strictly considered in a comprehensive multidisciplinary center

1n- and 2n-transfer with the Borromean nucleus 6^{6}He near the Coulomb barrier

Accepetd for publication in Physical Review LettersAngular distributions for 1n- and 2n-transfer are reported for the 6He + 65Cu system at Elab = 22.6 MeV. For the first time, triple coincidences between particles, neutrons and characteristic rays from the target-like residues were used to separate the contributions arising from 1n- and 2n-transfer. The differential cross sections for these channels, elastic scattering, and fusion were analyzed using a Coupled Reaction Channels approach. The large measured ratio of the 2n/1n cross section and the strong influence of 2n-transfer on other channels indicate that the di-neutron configuration of 6He plays a dominant role in the reaction mechanism

Putting residential flexibility management into action with pilot sites in Europe: From Mas2tering to DRIvE projects

The Mas2tering and DRIvE European projects develop a software platform to manage the residential and tertiary energy flexibility in local communities of prosumers. This platform includes forecasting, optimization, cybersecurity and fast-response capabilities modules. Business models and use cases were developed, taking into account the regulatory challenges. The platform will be implemented in five pilot sites across three countries