Opportunities for mesoscopics in thermometry and refrigeration: Physics and applications

This review presents an overview of the thermal properties of mesoscopic structures. The discussion is based on the concept of electron energy distribution, and, in particular, on controlling and probing it. The temperature of an electron gas is determined by this distribution: refrigeration is equivalent to narrowing it, and thermometry is probing its convolution with a function characterizing the measuring device. Temperature exists, strictly speaking, only in quasiequilibrium in which the distribution follows the Fermi-Dirac form. Interesting nonequilibrium deviations can occur due to slow relaxation rates of the electrons, e.g., among themselves or with lattice phonons. Observation and applications of nonequilibrium phenomena are also discussed. The focus in this paper is at low temperatures, primarily below 4 K, where physical phenomena on mesoscopic scales and hybrid combinations of various types of materials, e.g., superconductors, normal metals, insulators, and doped semiconductors, open up a rich variety of device concepts. This review starts with an introduction to theoretical concepts and experimental results on thermal properties of mesoscopic structures. Then thermometry and refrigeration are examined with an emphasis on experiments. An immediate application of solid-state refrigeration and thermometry is in ultrasensitive radiation detection, which is discussed in depth. This review concludes with a summary of pertinent fabrication methods of presented devices.Comment: Close to the version published in RMP; 59 pages, 35 figure

Chesapeake Bay National Estuarine Research Reserve in Virginia Management Plan: 2022-2027

Established through the Coastal Zone Management Act, the National Estuarine Research Reserve System (NERRS) represents a partnership program between the National Oceanic and Atmospheric Administration (NOAA) and the coastal states to promote informed management of the Nation’s estuaries and habitats. Designated in 1991, and administered by the Virginia Institute of Marine Science (VIMS) of William & Mary, the Chesapeake Bay National Estuarine Research Reserve in Virginia (CBNERR-VA or Reserve) is one of 30 protected areas, which encompass over 1.3 million acres and make up the NERRS. As the nation\u27s largest estuary, the Chesapeake Bay contains a diverse collection of habitats and salinity regimes. In order to incorporate the diversity of habitats in the lower Bay subregion, CBNERR-VA incorporates a multi-component network along the salinity gradient of the York River estuary (YRE). The Reserve’s four components are: (1) Goodwin Islands (148 ha; 366 ac), an archipelago of polyhaline saltmarsh islands surrounded by inter-tidal flats, extensive submerged aquatic vegetation beds, and shallow open estuarine waters near the mouth of the YRE; (2) Catlett Islands (220 ha; 542 ac), consisting of multiple parallel ridges of forested wetland hammocks, maritime-forest uplands, and emergent mesohaline salt marshes; (3) Taskinas Creek (433 ha; 1070 ac), containing non-tidal feeder streams that drain oak-hickory forests, maple-gum-ash swamps and freshwater marshes which transition into tidal oligo and mesohaline salt marshes; and (4) Sweet Hall Marsh (443 ha; 1094 ac), an extensive tidal freshwater-oligohaline marsh ecosystem located in the Pamunkey River, one of two major tributaries of the York River. This plan aligns with and complements the NERRS 2017-2022 Strategic Plan and VIMS\u27s 2015-2020 Strategic Plan while building upon previous accomplishments and the desire to address current priority issues and meet future challenges. Its intent is to provide a vision and framework to guide Reserve activities for program undertakings over the five-year period from 2022-2027