scholarly journals Determination of 50% endpoint titer using a simple formula

2016 ◽  
Vol 5 (2) ◽  
pp. 85 ◽  
Author(s):  
Muthannan Andavar Ramakrishnan
Keyword(s):  
Simple Formula ◽  
Endpoint Titer

scholarly journals The tidal oscillations in an elliptic basin of variable depth

1930 ◽  
Vol 130 (812) ◽  
pp. 157-167 ◽  
Keyword(s):  
Bessel Function ◽  
Simple Formula ◽  
Elliptic Cylinder ◽  
Long Waves ◽  
The Other ◽  
Transcendental Function ◽  
Algebraic Polynomials ◽  
Variable Depth ◽  
Numerical Approximations

The problem of the "long" waves in a circular basin of uniform depth involves in its solution a transcendental function–the Bessel function, and the determination of the free periods requires a knowledge of the zeros of this function or an allied function. On the other hand, when the basin, still circular, has a certain variable depth, it was shown by Lamb that the solution is expressed in terms of simple algebraic polynomials and the free periods of oscillation are expressed by an extremely simple formula. In similar fashion, the solution of the problem of the "long" waves in an elliptic basin of uniform depth involves the use of elliptic cylinder functions, and the free periods are only obtained as the result of lengthy numerical approximations.

XI. Contributions to our knowledge of antimony pentachloride

1887 ◽  
Vol 42 (251-257) ◽  
pp. 379-387
Keyword(s):  
Boiling Point ◽  
Simple Formula ◽  
Fundamental Importance ◽  
Antimony Pentachloride ◽  
Vapour Density

Some months ago we showed that antimony pentachloride can be distilled, undecomposed, under much diminished pressure; our next step was the attempt to determine the vapour-density under similar conditions. The fact that the boiling point of antimony pentachloride lies much lower than that of the trichloride would seem to show that the vapour-density of the pentachloride, as in the case of the trichloride, corresponds to the simpler formula. Nevertheless, on account of the fundamental importance which the establishment of the simple formula SbCl 5 would have for the valence of antimony, it seemed indispensably necessary to make a determination of the vapour-density.

scholarly journals The determination of pasture yield.

1956 ◽  
Vol 4 (4) ◽  
pp. 305-313
Author(s):  
S. Bosch
Keyword(s):  
Time Use ◽  
Simple Formula ◽  
N Fertilization ◽  
Standard Methods ◽  
Before And After ◽  
On Farm ◽  
Pasture Yield

The determination of gross yield, directly measured, and of net yield, indirectly calculated, are described and compared. In estimating gross yield, methods independent of farm use, in which fenced-off sections or cages are used, are compared with those dependent on farm use, in which strips are harvested before grazing. The amount of pasture grazed is determined from yields of mown plots before and after grazing by the use of a simple formula which agrees closely with Linehan's logarithmic formula. In calculating the net yield of starch equivalent from grazing time, use is made of Geith's norms for maintenance, production and growth. By using factors which allow for the very variable losses, according to methods of grazing and conservation, net yields can be converted to gross yields of starch equivalent. Fields can be directly compared by the use of standard methods and allowance made for different amounts of N fertilization.-J.F.C. (Abstract retrieved from CAB Abstracts by CABI’s permission)

scholarly journals Understanding the Bias between the Number of Confirmed Cases and Actual Number of Infections in the COVID-19 Pandemic

2020 ◽  
Author(s):  
Xingang Chen ◽  
Dhiraj Kumar Hazra
Keyword(s):  
Simple Formula ◽  
Historical Data ◽  
Theoretical Estimate ◽  
Actual Number ◽  
Test Volume ◽  
The Past ◽  
Daily Data ◽  
The Usa ◽  
Parameterization Model

AbstractThe number of positive cases confirmed in the viral tests is a probe of the actual number of infections of COVID-19. The bias between these two quantities is a key element underlying the determination of some important parameters of this disease and the policy-making during the pandemic. To study the dependence of this bias on measured variables, we introduce a parameterization model that motivates a method of organizing the daily data of the numbers of the total tests, confirmed cases, hospitalizations and fatalities. After comparing with the historical data of the USA in the past few months, we find a simple formula relating these four variables. As a few applications, we show, among other things, how this formula can be used to project the number of actual infections, to provide guidance on how the test volume should be adjusted, and to derive an upper bound on the overall infection fatality rate of COVID-19 (< 0.64%, 95% C.L.) and a theoretical estimate of its value.

Estimation of the Fatigue Life of a Transport Aircraft

1953 ◽  
Vol 57 (514) ◽  
pp. 613-617 ◽  
Author(s):  
P. B. Walker
Keyword(s):  
Fatigue Life ◽  
Simple Formula ◽  
Operating Conditions ◽  
Loading Cycle ◽  
Transport Aircraft ◽  
General Terms ◽  
Critical Components ◽  
Standard Life ◽  
Main Factor

SummaryA simple formula is presented for the safe life of an aircraft under reasonably good operating conditions from the standpoint of wing fatigue. Gusts are treated as the main factor in determination of fatigue life, though other factors are allowed for as being secondary. Before the formula can be used a simple fatigue test is required on critical components, and is repeated several times to establish variation of nominally identical specimens. The loading cycle for this test corresponds to a sequence of up and down gusts of 8 ft./sec. equivalent velocity. The life obtained is termed the “Standard Life” and corresponds to normal operating conditions on European air lines. Reservations in the use of the formula and correction for other operating conditions are discussed in general terms.

scholarly journals Performance Characteristics of the PolyTiter Immunofluorescent Titration System for Determination of Antinuclear Antibody Endpoint Dilution

2002 ◽  
Vol 9 (2) ◽  
pp. 329-332 ◽  
Author(s):  
Karen A. Flessland ◽  
Helen R. Landicho ◽  
Kimberlee K. Borden ◽  
Harry E. Prince
Keyword(s):  
Antinuclear Antibodies ◽  
Clinical Laboratory ◽  
Staining Intensity ◽  
Serial Dilution ◽  
Performance Characteristics ◽  
Coefficients Of Variation ◽  
Endpoint Control ◽  
Endpoint Titer ◽  
Titration System

ABSTRACT Conventional screening for circulating antinuclear antibodies (ANA) is generally performed by immunofluorescent (IF) microscopy with a 1:40 dilution of serum. Intensity of IF staining is then semiquantitated by using twofold serial dilutions, where the highest dilution in which staining intensity equals the endpoint control is expressed as an endpoint titer. The PolyTiter Immunofluorescent Titration system (Polymedco, Inc.) facilitates ANA-IF assay (IFA) testing by relating the intensity of IF staining to reference calibrators (defined in PolyTiter units), providing an endpoint titer directly from a 1:40 dilution. This study was conducted to assess the performance characteristics of the PolyTiter system. Two technologists each evaluated 10 replicates of three specimens and two controls on five sequential days. Endpoint dilution agreement (defined as ±2 dilutions) with the reference was 100% for all controls and for all specimens by one technologist. The second reader reported agreement of 98, 88, and 100% for the low, medium, and high specimens, respectively. Analysis of PolyTiter unit values yielded between-reader, between-run, and within-run precision coefficients of variation of less than 10%. The variance component in the lot-to-lot analysis was zero, indicating all of the variation was due to run-to-run differences. Overall endpoint dilution agreement between PolyTiter and serial dilution in the evaluation of 125 specimens at three sites was 90, 93, and 86%. Pattern identification with the PolyTiter was similar to that with serial dilution. The PolyTiter system demonstrates acceptable performance for routine ANA-IFA testing in the clinical laboratory.

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.

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