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2025
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2025
- Book : Volume 17()
- Pub. Date : 2025
- Page : pp.91-102
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2025
We present the design and commissioning of a cryogenic low-vibration test facility that measures displacement noise from a gram-scale silicon cantilever at the level of 10−16m/Hz at 1 kHz. This sensitivity is necessary for future tests of thermal noise models on cross sections of silicon suspension samples proposed for future gravitational-wave detectors. A volume of ∼36 l is enclosed by radiation shields cooling an optical test cavity that is suspended from a multi-stage pendulum chain providing isolation from acoustic and environmental noise. This 3 kg test cavity housing a crystalline silicon cantilever is radiatively cooled to 123 K in 41 h and held at that temperature over many months with a relative temperature stability of ±1 mK. The facility housing the test cavity is sensitive to cavity length changes, which can resolve thermal fluctuations at the desired sensitivity. It is capable of interferometrically measuring temperature-dependent broadband displacement noise directly between 50 Hz and 10 kHz, where current and future ground-based gravitational wave observatories are the most sensitive. With a suitable cantilever design, the cryogenic facility we describe here will allow for the measurement of broadband thermal noise in crystalline silicon at 123 K. This will guide the design of suspensions in planned future cryogenic ground-based gravitational-wave detectors such as LIGO Voyager and may have implications for suspensions in the Einstein Telescope. This facility is also suitable for the testing of new mirror coatings at cryogenic temperatures.- Book : 96(1)
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2025
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2025
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2025
Thermoelectric effects in p–n junctions are widely used for energy generation with thermal gradients, creation of compact Peltier refrigerators and, most recently, for sensitive detection of infrared and terahertz radiation. It is conventionally assumed that electrons and holes creating thermoelectric current are in equilibrium and share the common quasi-Fermi level. We show that lack of interband equilibrium results in an anomalous sign and magnitude of thermoelectric voltage developed across the p–n junction. The anomalies appear provided the diffusion length of minority carriers exceeds the size of hot spot at the junction. Normal magnitude of thermoelectric voltage is partly restored if interband tunneling at the junction is allowed. The predicted effects can be relevant to the cryogenically cooled photodetectors based on bilayer graphene and mercury cadmium telluride quantum wells.- Book : ()
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2025
In Europe, there is a growing concern for animal welfare, encompassing both their rights and health. Consequently, identifying biomarkers that predict serious pathological conditions has become crucial in veterinary medicine. The Buccal Micronucleus Cytome (BMCyt) assay is a minimally invasive method that uses biomarkers to evaluate DNA damage and chromosomal instability, using exfoliated buccal cells. A rising frequency of anomalies, such as micronuclei formation, strongly indicates an elevated risk of cancer, neurodegenerative diseases, or accelerated aging, potentially originating from exposure to genotoxins and cytotoxins. This method has been validated in humans, but very little research has been conducted on animals. This work aims to provide a detailed description of an optimized method for collecting buccal exfoliated cells in dogs and to characterize a biomarker related to genomic damage using optical and fluorescent microscopy. Samples from dogs in breeding kennels, including pregnant animals, were tested for chromosomal instability. By following procedures similar to those used in humans, we were able to detect and count major nuclear abnormalities. The percentage of micronuclei was higher compared to other studies. Technical aspects, such as avoiding artifacts and ensuring prior training of the operator, must be taken into account. This work validated the BMCyt method for collecting and processing samples in dogs, potentially enhancing the understanding of micronuclei as biomarkers for pre-pathological states in canines.- Book : 15(3)
- Pub. Date : 2025
- Page : pp.382-382
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2025
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2025
Abstract. This work presents a field study measuring aeolian sediment transport and wind profiles across a dune, and provides an approximation of the annual volume of aeolian transport into the dune systems of the East Frisian island of Spiekeroog, using commonly available meteorological data. Aeolian sediment traps were positioned along a transect aligned with the general wind direction during the measurement, starting on the open beach and ending on the back site of a selected dune. Wind profiles were temporarily measured next to four aeolian traps. Using a recent version of an aeolian sediment transport model, the total annual aeolian sediment transport into the dune systems is approximated. Input variables for this model are the time series of shear velocity and surface moisture. These are derived from the wind velocity measured at a height of 10 m and the amount of precipitation in combination with potential evaporation calculated using radiation intensity. The results are compared to volume changes of the beach and dune systems, which are derived from geospatial data. Data from the field study shows, that sediment transport occurs even behind twenty metres of vegetation on top of a dune. Further, the study indicates that the impact of precipitation on aeolian transport reduction can be lower within vegetated areas on a dune compared to the open beach. The approximation of the total annual aeolian transported sediment surpasses the actual volume changes of the dune systems as expected, however this difference varies depending on the compared beach section almost by a factor of five.
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