Determination of Organic and Inorganic Percentages and Mass of Suspended Material at Four Sites in the Illinois River in Northwestern Arkansas and Northeastern Oklahoma, 2005-07

2008 ◽  
Author(s):  
Joel M. Galloway
Keyword(s):  
Illinois River ◽  
Suspended Material

scholarly journals The Plankton of the Illinois River. 1894-1899, with Introductory Notes upon the Hydrography of the Illinois River and Its Basin.

1903 ◽  
Vol 6 (1-2) ◽  
pp. 95-629 ◽  
Author(s):  
C. A. Kofoid
Keyword(s):  
Statistical Methods ◽  
Seasonal Changes ◽  
Life Histories ◽  
Illinois River ◽  
Aquatic Life ◽  
Biological Station ◽  
Biological Population ◽  
Specific Determination

When the work of the Illinois Biological Station was begun in 1894. it seemed to the Director desirable to determine as far as possible the normal routine of aquatic life as a necessary basis for the detection of problems for investigationand experiment, and as an indispensable background for their adequate solution. Such an investigation demands not only the discovery and specific determination of the biological population, but involves also the study of life histories, seasonal changes, and mutual dependencies of the assembled organisms by quantitative and statistical methods, together with a study of the environment and an analysis of its factors.

Rapid Determination of Tryptophan in Intact Proteins by Derivative Spectrophotometry

1993 ◽  
Vol 76 (6) ◽  
pp. 1168-1173 ◽  
Author(s):  
Dimitrios J Fletouris ◽  
Nickos A Botsoglou ◽  
Georgios E Papageorgiou ◽  
Antonios J Mantis
Keyword(s):  
Rapid Determination ◽  
Suspended Material ◽  
Feed Ingredient ◽  
Intact Proteins ◽  
Sample Extract ◽  
Tryptophan Residues ◽  
Food And Feed ◽  
Fourth Derivative ◽  
Uv Absorption Spectrum

Abstract A method for rapid determination of total tryptophan in intact proteins was developed. Sample is homogenized with 0.1 M sodium hydroxide, and the homogenate, if it contains suspended material, is centrifuged. Tryptophan is directly quantified in sample extract on the basis of its fourth-derivative UV absorption spectrum. Protein hydrolysis and/or extract purification is not required because the fourth-derivative transformation of the conventional analytical band around 285.5 nm virtually eliminates interferences arising from both tyrosine and other UV-absorbing components. When pure proteins were analyzed by the method, the values of tryptophan residues found coincided well with literature data based on sequence analysis. The applicability of the method was also tested on several food and feed ingredient samples selected to include a range of protein content and a variety of protein sources. Owing to its simplicity and reliability, the method is particularly recommended for everyday analysis of a large number of samples.

Problems in extraction and spectrophotometric determination of chlorophyll from epilithic microbial biofilms: towards a standard method

1999 ◽  
Vol 79 (3) ◽  
pp. 551-558 ◽  
Author(s):  
R.C. Thompson ◽  
M.L. Tobin ◽  
S.J. Hawkins ◽  
T.A. Norton
Keyword(s):  
Standard Method ◽  
Relative Efficiency ◽  
Room Temperature ◽  
Standard Procedure ◽  
Suspended Material ◽  
Sample Collection ◽  
Simple Method ◽  
Microbial Biofilms ◽  
Epilithic Biofilms

A variety of methods are available to extract chlorophyll from epilithic biofilms using solvents. The relative efficiency of these has not been determined simultaneously and there is no recognized standard procedure. In this paper techniques for sample collection, storage, preparation and extraction are reviewed and compared experimentally.Extraction of chlorophyll was incomplete unless biofilms were fully hydrated. This factor was highly significant for all the solvents tested, with at least three times more pigment being extracted from hydrated samples than from dry ones. Methanol was the most efficient solvent, releasing over 96% of the total chlorophyll during a single extraction; hot ethanol extracted 86%, while acetone extracted less than 50%. Sonicating samples during extraction did not release any additional pigment. Centrifuging to remove suspended material did not alter estimates and was not advantageous. Rugose rock surfaces released more chlorophyll than smooth ones. However, a simple method to quantify surface rugosity at an appropriate scale was not available.Based on these observations, a standard method for chlorophyll extractions from epilithic biofilms using 100% methanol at room temperature (20°C) is proposed. This technique requires considerably less supervision than previously preferred methods and gave a chlorophyll extract which was stable for 15 h.

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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