scholarly journals Determination of the particulate absorption of microalgae using a point-source integrating-cavity absorption meter: verification with a photometric technique, improvements for pigment bleaching, and correction for chlorophyll fluorescence

2007 ◽  
Vol 5 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Rüdiger Röttgers ◽  
Clivia Häse ◽  
Roland Doerffer
Keyword(s):  
Chlorophyll Fluorescence ◽  
Point Source ◽  
Photometric Technique

Validation of an Inverse Method for the Source Determination of a Hazardous Airborne Material Released from a Point Source in an Urban Environment

2017 ◽  
pp. 329-332 ◽  
Author(s):  
George C. Efthimiou ◽  
Spyros Andronopoulos ◽  
Ivan V. Kovalets ◽  
Alexandros Venetsanos ◽  
Christos D. Argyropoulos ◽  
...  
Keyword(s):  
Point Source ◽  
Urban Environment ◽  
Inverse Method ◽  
Source Determination

Improved determination of the position and activity of a radioactive point source inside a bulky medium using several detectors. The special case of a lung counter—A general view

2007 ◽  
Vol 65 (2) ◽  
pp. 234-238
Author(s):  
Omer Pelled ◽  
Mauro L. Bonardi ◽  
Uzi German ◽  
Flavia Groppi ◽  
Zeev B. Alfassi
Keyword(s):  
Point Source ◽  
General View ◽  
Special Case

Determination of point source mechanisms

2014 ◽  
pp. 108-134 ◽  
Author(s):  
Agustin Udias ◽  
Raul Madariaga ◽  
Elisa Buforn
Keyword(s):  
Point Source ◽  
Source Mechanisms

scholarly journals Determination of the influence of herbicides on dicotyledons plant transpiration using the sap flow method

2014 ◽  
Vol 60 (No. 12) ◽  
pp. 562-568 ◽  
Author(s):  
V. Brant ◽  
J. Pivec ◽  
K. Hamouzová ◽  
P. Zábranský ◽  
J. Satrapová ◽  
...  
Keyword(s):  
Chlorophyll Fluorescence ◽  
Transpiration Rate ◽  
Sap Flow ◽  
Herbicide Application ◽  
Plant Transpiration ◽  
Flow Method ◽  
Infrared Gas Analyser ◽  
The Impact ◽  
Q Values

Physiological parameters are sensitive and provide information on the toxicity of herbicides in plants. The impact of herbicide application on plant transpiration was evaluated by the sap flow method during 2009&ndash;2011. The aim of this work was to verify the sap flow method for determining the effect of herbicides on the basis of continuous measurements of the transpiration flow. Helianthus annuus was used as a model plant species. The two different herbicides tested in this study differed by the effect of active ingredients bromoxynil and clopyralid. The water flow was measured using sap flow meter T4.2. The impact of herbicides was assessed by comparing measured transpiration rate (Q) after herbicide application with an extrapolation of transpiration rate of plants before herbicide treatment (Q<sub>calc</sub>). After treatment with bromoxynil the Q values decreased significantly compared to Q<sub>calc</sub>. For plants treated by clopyralid, the decline of actual transpiration (Q) compared with the modelled one (Q<sub>calc</sub>) was less substantial and the plants continued to transpire after the treatment. The effect of herbicides was also verified using infrared gas analyser and chlorophyll fluorescence meter.

scholarly journals Image Reconstruction from VLBI Amplitude and Phase Closure Data

1979 ◽  
Vol 49 ◽  
pp. 93-93
Author(s):  
William D. Cotton ◽  
Jill J. Wittels
Keyword(s):  
Point Source ◽  
Direct Synthesis ◽  
Angular Structure ◽  
Long Baseline ◽  
Test Models ◽  
Step Procedure ◽  
Source Convergence ◽  
Using Data ◽  
Starting Model

AbstractA two step procedure is developed for the determination of the angular structure of the compact components of radio sources from observations made with very long baseline interferometry (VLBI). The first step is to fit a model composed of circularly symmetric Gaussian components to the observations. Then this, or any other, model and closure phase information is used to predict visibility phases which, when paired with the corresponding visibility amplitude observation, are combined in a direct synthesis; the resulting map is deconvolved from the point source response by means of the “CLEAN” procedure. If necessary, the “cleaned” components can be used as a starting model to predict visibility phases and the process iterated. The initial model in many cases may be as simple as a point source. Convergence of this process appears to be quite rapid, requiring only a few iterations when the source is simple or the starting model is good. These two steps for source mapping can be used either together or separately. Examples are given using data generated from test models.

scholarly journals Modelling the thermal radiation from kitchen hob fires

2020 ◽  
Vol 38 (4) ◽  
pp. 377-394
Author(s):  
Michael Spearpoint ◽  
Charlie Hopkin ◽  
Danny Hopkin
Keyword(s):  
Heat Flux ◽  
Point Source ◽  
Radial Distance ◽  
Source Model ◽  
View Factor ◽  
Calculation Methods ◽  
Fire Dynamics ◽  
Potential Threat ◽  
Computational Tools

Kitchen hob fires present a potential threat to occupants escaping from dwellings and calculations may be needed to assess the hazard. Determination of the thermal heat flux from flames to a target can be achieved through the use of hand calculation methods or computational tools. This article compares point source, parallel plane and cylindrical view factor hand calculations and computational simulations using B-RISK and Fire Dynamics Simulator of thermal heat flux with kitchen hob fire experiments presented in the literature. Knowing the level of accuracy of each method provides useful information to designers. Although the point source model is influenced by whether the radial distance is measured perpendicular to the heat flux target or is offset relative to the centre of the flame, the article concludes that it provides an adequate approach for the calculation of thermal heat flux in the case of kitchen hob fires.

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