Tristatic EISCAT-UHF measurements of the HF modified ionosphere for low background electron temperatures

1995 ◽  
Vol 100 (A6) ◽  
pp. 9717 ◽  
Author(s):  
A. Westman ◽  
T. B. Leyser ◽  
G. Wannberg ◽  
M. T. Rietveld
Keyword(s):  
Low Background ◽  
Uhf Measurements

A vacuum chamber for low background diffraction experiments

1996 ◽  
Vol 211 (9) ◽  
Author(s):  
R. B. Neder ◽  
M. Burghammer ◽  
Th. Grasl ◽  
H. Schulz
Keyword(s):  
Single Crystal ◽  
Vacuum Chamber ◽  
Single Crystal Diffraction ◽  
Low Background

AbstractWe developed a small vacuum chamber for very low background single crystal diffraction experiments. The chamber has been designed for a large Eulerian cradle. The

A CONCRETE LOW-BACKGROUND COUNTING ENCLOSURE

1964 ◽  
Author(s):  
H. A. Wollenberg ◽  
A. R. Smith
Keyword(s):  
Low Background ◽  
Background Counting

scholarly journals Improving the Precision of Calibrating a Large Low-background Proportional Counter

2020 ◽  
Vol 1690 ◽  
pp. 012037
Author(s):  
O D Petrenko ◽  
A M Gangapshev ◽  
Yu M Gavrilyuk ◽  
V V Kazalov ◽  
V V Kuzminov ◽  
...  
Keyword(s):  
Proportional Counter ◽  
Low Background

A low-background fluorescent aptasensor for acetamiprid detection based on DNA three-way junction-formed G-quadruplexes and graphene oxide

2021 ◽  
Vol 413 (8) ◽  
pp. 2071-2079
Author(s):  
Yunwei Zhao ◽  
Hui Zhang ◽  
Ying Wang ◽  
Yanfang Zhao ◽  
Yaowei Li ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Low Background ◽  
Fluorescent Aptasensor

Dispersion and abundance of Maritrema arenaria in Semibalanus balanoides in north-east Ireland

1990 ◽  
Vol 64 (2) ◽  
pp. 151-160 ◽  
Author(s):  
H. Carrol ◽  
W. I. Montgomery ◽  
R. E. B. Hanna
Keyword(s):  
Size Structure ◽  
Background Level ◽  
Host Population ◽  
Parasite Infection ◽  
Semibalanus Balanoides ◽  
Low Background ◽  
Digenean Trematode ◽  
North East ◽  
Parasitic Burden ◽  
A Site

ABSTRACTInfection of the barnacle Semibalanus balanoides with the digenean trematode Maritrema arenaria was investigated at 17 sites along the Co. Down coastline. There was a low background level of infection. Abundance of M. arenaria, however, was substantially greater at sites close to fish factories and at a site close to a sewage works. Aggregation of M. arenaria in S. balanoides was least marked at low mean parasite burdens. The parasitic burden was related more closely to barnacle size at a site of heavy infection than at one with a low abundance. There was a significant association between height on the shore and number of encysted metacercariae in S. balanoides. This was independent of variation in host size. It is concluded that relationships that bring about overdispersion of digeneans, such as that between the size-structure of the host population and parasite infection, may be dependent on the overall abundance of the parasite.

scholarly journals Upconversion Spectral Rulers for Transcutaneous Displacement Measurements

Sensors ◽  
2021 ◽  
Vol 21 (10) ◽  
pp. 3554
Author(s):  
Melissa M. Suckey ◽  
Donald W. Benza ◽  
John D. DesJardins ◽  
Jeffrey N. Anker
Keyword(s):  
Optical Measurement ◽  
Optical Measurements ◽  
Small Displacement ◽  
Simple Method ◽  
Low Background ◽  
X Ray ◽  
Optical Displacement ◽  
Spectral Peaks ◽  
Displacement Measurements ◽  
Minimal Intensity

We describe a method to measure micron to millimeter displacement through tissue using an upconversion spectral ruler. Measuring stiffness (displacement under load) in muscles, bones, ligaments, and tendons is important for studying and monitoring healing of injuries. Optical displacement measurements are useful because they are sensitive and noninvasive. Optical measurements through tissue must use spectral rather than imaging approaches because optical scattering in the tissue blurs the image with a point spread function typically around the depth of the tissue. Additionally, the optical measurement should have low background and minimal intensity dependence. Previously, we demonstrated a spectral encoder using either X-ray luminescence or fluorescence, but the X-ray luminescence required an expensive X-ray source and used ionizing radiation, while the fluorescence sensor suffered from interference from autofluorescence. Here, we used upconversion, which can be provided with a simple fiber-coupled spectrometer with essentially autofluorescence-free signals. The upconversion phosphors provide a low background signal, and the use of closely spaced spectral peaks minimizes spectral distortion from the tissue. The small displacement noise level (precision) through tissue was 2 µm when using a microscope-coupled spectrometer to collect light. We also showed proof of principle for measuring strain on a tendon mimic. The approach provides a simple method to study biomechanics using implantable sensors.

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