Measuring techniques for environmental levels of radon-220 in air using flow-through Lucas cell and multiple time analysis of recorded pulse events

1992 ◽  
Vol 43 (1-2) ◽  
pp. 111-118 ◽  
Author(s):  
Rolf Falk ◽  
Hans Möre ◽  
Leif Nyblom
Keyword(s):  
Multiple Time ◽  
Time Analysis ◽  
Measuring Techniques ◽  
Flow Through ◽  
Lucas Cell

scholarly journals Warming and Weakening of the Abyssal Flow through Samoan Passage

2016 ◽  
Vol 46 (8) ◽  
pp. 2389-2401 ◽  
Author(s):  
Gunnar Voet ◽  
Matthew H. Alford ◽  
James B. Girton ◽  
Glenn S. Carter ◽  
John B. Mickett ◽  
...  
Keyword(s):  
Time Series ◽  
North Pacific ◽  
Volume Transport ◽  
Meridional Overturning Circulation ◽  
Multiple Time Scales ◽  
Multiple Time ◽  
Confidence Limits ◽  
The North ◽  
Meridional Overturning ◽  
Flow Through

AbstractThe abyssal flow of water through the Samoan Passage accounts for the majority of the bottom water renewal in the North Pacific, thereby making it an important element of the meridional overturning circulation. Here the authors report recent measurements of the flow of dense waters of Antarctic and North Atlantic origin through the Samoan Passage. A 15-month long moored time series of velocity and temperature of the abyssal flow was recorded between 2012 and 2013. This allows for an update of the only prior volume transport time series from the Samoan Passage from WOCE moored measurements between 1992 and 1994. While highly variable on multiple time scales, the overall pattern of the abyssal flow through the Samoan Passage was remarkably steady. The time-mean northward volume transport of about 5.4 Sv (1 Sv ≡ 106 m3 s−1) in 2012/13 was reduced compared to 6.0 Sv measured between 1992 and 1994. This volume transport reduction is significant within 68% confidence limits (±0.4 Sv) but not at 95% confidence limits (±0.6 Sv). In agreement with recent studies of the abyssal Pacific, the bottom flow through the Samoan Passage warmed significantly on average by 1 × 10−3°C yr−1 over the past two decades, as observed both in moored and shipboard hydrographic observations. While the warming reflects the recently observed increasing role of the deep oceans for heat uptake, decreasing flow through Samoan Passage may indicate a future weakening of this trend for the abyssal North Pacific.

scholarly journals A Research Study on the Radiological State of Building Material and the Risk Assessment

2020 ◽  
Vol 6 ◽  
pp. 313
Author(s):  
A. Savidou ◽  
C. Raptis ◽  
P. Kritidis
Keyword(s):  
Building Materials ◽  
Gamma Ray ◽  
Scintillation Counter ◽  
Natural Radionuclide ◽  
Radon Exhalation ◽  
Radionuclide Content ◽  
Flow Through ◽  
Materials Used ◽  
Lucas Cell ◽  
Continuous Accumulation

The objective of the present study is focused an the assessment of the radiological risk from building materials used in Attica region, Greece. Bricks and concrete com- monly used in Attica region have been studied for both natural radionuclide content and radon exhalation. The high-resolution gamma-ray spectroscopy technique, as well as radon exhalation measurements, have been employed. The technique used for the measurements of the radon exhalation is called "continuous accumulation- counting" method and has been described in detail by the authors in earlier pub- lications. This measurement technique is based on the continuous air flow through a sealed chamber containing the sample and through a scintillation counter (Lucas cell). The counting is continuous as well.

scholarly journals Effects of Deforestation on Water Flow in the Vadose Zone

Water ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 35 ◽  
Author(s):  
Inge Wiekenkamp ◽  
Johan Alexander Huisman ◽  
Heye Reemt Bogena ◽  
Harry Vereecken
Keyword(s):  
Land Use ◽  
Water Flow ◽  
Preferential Flow ◽  
Pore Space ◽  
Sensor Response ◽  
Total Precipitation ◽  
Response Time Analysis ◽  
Time Analysis ◽  
Piston Flow ◽  
Flow Through

The effects of land use change on the occurrence and frequency of preferential flow (fast water flow through a small fraction of the pore space) and piston flow (slower water flow through a large fraction of the pore space) are still not fully understood. In this study, we used a five year high resolution soil moisture monitoring dataset in combination with a response time analysis to identify factors that control preferential and piston flow before and after partial deforestation in a small headwater catchment. The sensor response times at 5, 20 and 50 cm depths were classified into one of four classes: (1) non-sequential preferential flow, (2) velocity based preferential flow, (3) sequential (piston) flow, and (4) no response. The results of this analysis showed that partial deforestation increased sequential flow occurrence and decreased the occurrence of no flow in the deforested area. Similar precipitation conditions (total precipitation) after deforestation caused more sequential flow in the deforested area, which was attributed to higher antecedent moisture conditions and the lack of interception. At the same time, an increase in preferential flow occurrence was also observed for events with identical total precipitation. However, as the events in the treatment period (after deforestation) generally had lower total, maximum, and mean precipitation, this effect was not observed in the overall occurrence of preferential flow. The results of this analysis demonstrate that the combination of a sensor response time analysis and a soil moisture dataset that includes pre- and post-deforestation conditions can offer new insights in preferential and sequential flow conditions after land use change.

Development of apical pits in chloride cells of the gills of Pimephales promelas after chronic exposure to acid water

1983 ◽  
Vol 41 ◽  
pp. 462-463
Author(s):  
Richard L. Leino ◽  
Jon G. Anderson ◽  
J. Howard McCormick
Keyword(s):  
Confidence Interval ◽  
Chronic Exposure ◽  
Lake Superior ◽  
Pimephales Promelas ◽  
Chloride Cells ◽  
Fathead Minnows ◽  
Secondary Lamellae ◽  
Untreated Water ◽  
Water Ph ◽  
Flow Through

Groups of 12 fathead minnows were exposed for 129 days to Lake Superior water acidified (pH 5.0, 5.5, 6.0 or 6.5) with reagent grade H2SO4 by means of a multichannel toxicant system for flow-through bioassays. Untreated water (pH 7.5) had the following properties: hardness 45.3 ± 0.3 (95% confidence interval) mg/1 as CaCO3; alkalinity 42.6 ± 0.2 mg/1; Cl- 0.03 meq/1; Na+ 0.05 meq/1; K+ 0.01 meq/1; Ca2+ 0.68 meq/1; Mg2+ 0.26 meq/1; dissolved O2 5.8 ± 0.3 mg/1; free CO2 3.2 ± 0.4 mg/1; T= 24.3 ± 0.1°C. The 1st, 2nd and 3rd gills were subsequently processed for LM (methacrylate), TEM and SEM respectively.Three changes involving chloride cells were correlated with increasing acidity: 1) the appearance of apical pits (figs. 2,5 as compared to figs. 1, 3,4) in chloride cells (about 22% of the chloride cells had pits at pH 5.0); 2) increases in their numbers and 3) increases in the % of these cells in the epithelium of the secondary lamellae.

An Interactive Minicomputer Program for the Indexing and Simulation of Electron Diffraction Patterns

1976 ◽  
Vol 34 ◽  
pp. 542-543
Author(s):  
R.P. Goehner ◽  
W.T. Hatfield ◽  
Prakash Rao
Keyword(s):  
Electron Diffraction ◽  
Real Time ◽  
Pattern Analysis ◽  
Flow Diagram ◽  
Hard Copy ◽  
Time Analysis ◽  
Real Time Analysis ◽  
Transmission Electron ◽  
One Step ◽  
Diffraction Patterns

Computer programs are now available in various laboratories for the indexing and simulation of transmission electron diffraction patterns. Although these programs address themselves to the solution of various aspects of the indexing and simulation process, the ultimate goal is to perform real time diffraction pattern analysis directly off of the imaging screen of the transmission electron microscope. The program to be described in this paper represents one step prior to real time analysis. It involves the combination of two programs, described in an earlier paper(l), into a single program for use on an interactive basis with a minicomputer. In our case, the minicomputer is an INTERDATA 70 equipped with a Tektronix 4010-1 graphical display terminal and hard copy unit.A simplified flow diagram of the combined program, written in Fortran IV, is shown in Figure 1. It consists of two programs INDEX and TEDP which index and simulate electron diffraction patterns respectively. The user has the option of choosing either the indexing or simulating aspects of the combined program.

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