Determination of the Odor Threshold Concentrations of Chlorobrominated Anisoles in Water

2005 ◽  
Vol 53 (2) ◽  
pp. 383-387 ◽  
Author(s):  
Alfredo Diaz ◽  
Cristina Fabrellas ◽  
Francesc Ventura ◽  
M. Teresa Galceran
Keyword(s):  
Odor Threshold

scholarly journals Odor Threshold Determination of 53 Odorant Chemicals

1974 ◽  
Vol 3 (8) ◽  
pp. 579-585 ◽  
Author(s):  
G. Leonardos ◽  
D. Kendall ◽  
N. Barnard
Keyword(s):  
Odor Threshold ◽  
Threshold Determination

SELECTION AND TREA1MENT CF PANELISTS FOR DETERMINATION OF ODOR THRESHOIDS M. Hangartner Swiss Federal Institute of Technology, Department of Hygiene and Applied Physiology In order to harmonize an odor measurement technique, national guide­ lines or recaimendations from Germany, France, the Netherlands and the United Kingdom are compared with respect to selection and treat­ ment of panelists. Different methods of mathematical treatment of threshold data are also presented. 1. INTRODUCTION The task of the working group "odours" in working party one of the COST 681 programme on processing and use of sewage sludge is to give a contribution to harmonize an odor measurement technique. For this purpose the national guidelines or recommendations from Germany, France, the Netherlands and the United Kingdom are compared. The emphasis of this paper lies on selection and treatment of panelists for odor threshold determination. It is well known that sensitivity of men to odorants varies within a large range. By selecting the panelists at one extreme of the sensiti­ vity distribution, the result can be falsified. However, by chosing a large number of panelists, this effect can be minimized, but this is often not suitable in practise. In the following the different reccmnen-dations are presented. Another source of variation of threshold values is the treatment of panelists, that means comfort, motivation, interaction with panelleader, adaptation etc. These effects can be reduced using a proper detection method. Finally, different methods for threshold data treatment may pro­ duce different threshold values. For comparison, the following guidelines are reviewed: Germany - VDI Guideline 3881: Olfactometric method of odor threshold determina­ tion, Fundamentals (Nov., 1983) France - AFNOR Standard: Air pollution - Method of measuring odors from gaseous effluents determination of the dilution factor of the threshold of per­ ception (1982) Netherlands - Odor standard, Ministerie van Volkshuisevesting (1983) United Kingdom - Odor control - a concise guide prepared on behalf of the Department of the Environment Warren Spring Laboratory (1980)

1986 ◽  
pp. 69-69
Keyword(s):  
United Kingdom ◽  
The Netherlands ◽  
Measurement Technique ◽  
Working Party ◽  
Odor Threshold ◽  
Threshold Values ◽  
The United Kingdom ◽  
Threshold Data ◽  
Institute Of Technology

Determination of the Odor Threshold Concentrations Of Iodinated Trihalomethanes in Drinking Water

2001 ◽  
Vol 49 (4) ◽  
pp. 1881-1884 ◽  
Author(s):  
Beatriz Cancho ◽  
Cristina Fabrellas ◽  
Alfredo Diaz ◽  
Francesc Ventura ◽  
M Teresa Galceran
Keyword(s):  
Drinking Water ◽  
Odor Threshold

The Interaction of Mixing Odorants with Similar Chemical Properties: A Case Study on Ketone Compounds

2013 ◽  
Vol 850-851 ◽  
pp. 32-37 ◽  
Author(s):  
Peng Zhao ◽  
Jie Min Liu ◽  
Shi Chuan Tang
Keyword(s):  
Empirical Relationship ◽  
Chemical Properties ◽  
Odor Intensity ◽  
Synthetic Mixture ◽  
Odor Threshold ◽  
Similar Chemical ◽  
Wide Range ◽  
The Common

To investigate more about the interaction of mixing odorants, a series of sensory tests were conducted using five ketones [butanone (Bu), 2-Pentanone (Pe), 2-Hexanone (Hex), 2-Heptanone (Hep), 2-Octanone (Oc)] at varying concentration levels. The determination of odor threshold (OT) was initially conducted by the triangle odor bag method (GB/T 14675, China). The odor activity values (OAVs) of individual odorants at a wide range of concentrations were derived from concentration-to-odor threshold ratios. The resulting data were then evaluated to define the empirical relationship for each ketone between the OAV and odor intensity (OI) scaling. Based on the relationships defined for each individual ketone, the OI values were estimated for a synthetic mixture of five ketones. The effect of mixing was then examined by assessing those estimated OI values with the actually measured OI values. The overall results of this study confirmed that the OI values of the synthetic mixture is not governed by the common theoretical basis (e.g., rule of additivity, synergism, or a stronger component model) but is best represented by the averaged contribution of all ketone components. Thus, the odor intensity (OI) of a given mixture sample containing odorants with similar chemical properties can be accessed through the conversion from its concentration value with the application of empirical equations instead of direct measurement by the human test panel.

Galactic orbits of stars

1966 ◽  
Vol 25 ◽  
pp. 93-97
Author(s):  
Richard Woolley
Keyword(s):  
Globular Cluster ◽  
Potential Field ◽  
High Velocity ◽  
Velocity Vector ◽  
Variable Stars ◽  
The Sun ◽  
Proper Motions ◽  
Rr Lyrae ◽  
The Galaxy

It is now possible to determine proper motions of high-velocity objects in such a way as to obtain with some accuracy the velocity vector relevant to the Sun. If a potential field of the Galaxy is assumed, one can compute an actual orbit. A determination of the velocity of the globular clusterωCentauri has recently been completed at Greenwich, and it is found that the orbit is strongly retrograde in the Galaxy. Similar calculations may be made, though with less certainty, in the case of RR Lyrae variable stars.

Distance to SN 1987A and the LMC

1999 ◽  
Vol 190 ◽  
pp. 549-554
Author(s):  
Nino Panagia
Keyword(s):  
Angular Size ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Light Curves ◽  
Distance Modulus ◽  
Absolute Size ◽  
Sn 1987A

Using the new reductions of the IUE light curves by Sonneborn et al. (1997) and an extensive set of HST images of SN 1987A we have repeated and improved Panagia et al. (1991) analysis to obtain a better determination of the distance to the supernova. In this way we have derived an absolute size of the ringRabs= (6.23 ± 0.08) x 1017cm and an angular sizeR″ = 808 ± 17 mas, which give a distance to the supernovad(SN1987A) = 51.4 ± 1.2 kpc and a distance modulusm–M(SN1987A) = 18.55 ± 0.05. Allowing for a displacement of SN 1987A position relative to the LMC center, the distance to the barycenter of the Large Magellanic Cloud is also estimated to bed(LMC) = 52.0±1.3 kpc, which corresponds to a distance modulus ofm–M(LMC) = 18.58±0.05.

International determination of the total motion of the pole

1961 ◽  
Vol 13 ◽  
pp. 29-41
Author(s):  
Wm. Markowitz
Keyword(s):  
Secular Motion ◽  
The Future

A symposium on the future of the International Latitude Service (I. L. S.) is to be held in Helsinki in July 1960. My report for the symposium consists of two parts. Part I, denoded (Mk I) was published [1] earlier in 1960 under the title “Latitude and Longitude, and the Secular Motion of the Pole”. Part II is the present paper, denoded (Mk II).

Time and Latitude in South Africa

1972 ◽  
Vol 1 ◽  
pp. 27-38
Author(s):  
J. Hers
Keyword(s):  
South Africa ◽  
Cape Town ◽  
Astronomical Observations ◽  
Royal Observatory ◽  
The Republic ◽  
Astronomical Determination ◽  
Limited Accuracy ◽  
Better Than

In South Africa the modern outlook towards time may be said to have started in 1948. Both the two major observatories, The Royal Observatory in Cape Town and the Union Observatory (now known as the Republic Observatory) in Johannesburg had, of course, been involved in the astronomical determination of time almost from their inception, and the Johannesburg Observatory has been responsible for the official time of South Africa since 1908. However the pendulum clocks then in use could not be relied on to provide an accuracy better than about 1/10 second, which was of the same order as that of the astronomical observations. It is doubtful if much use was made of even this limited accuracy outside the two observatories, and although there may – occasionally have been a demand for more accurate time, it was certainly not voiced.

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