Growth variability in avian embryos as a source of experimental error

1994 ◽  
Vol 8 (6) ◽  
pp. 515-520 ◽  
Author(s):  
Francisco F. Terol ◽  
Alfonso Panchon-Ruiz
Keyword(s):  
Experimental Error ◽  
Growth Variability ◽  
Avian Embryos

The Estimation of Blood Platelet Survival

1972 ◽  
Vol 28 (03) ◽  
pp. 447-456 ◽  
Author(s):  
E. A Murphy ◽  
M. E Francis ◽  
J. F Mustard
Keyword(s):  
Standard Deviation ◽  
Least Squares ◽  
Experimental Error ◽  
Blood Platelet ◽  
Least Squares Estimation ◽  
Systematic Relationship ◽  
Platelet Survival ◽  
The Mean ◽  
Normally Distributed

SummaryThe characteristics of experimental error in measurement of platelet radioactivity have been explored by blind replicate determinations on specimens taken on several days on each of three Walker hounds.Analysis suggests that it is not unreasonable to suppose that error for each sample is normally distributed ; and while there is evidence that the variance is heterogeneous, no systematic relationship has been discovered between the mean and the standard deviation of the determinations on individual samples. Thus, since it would be impracticable for investigators to do replicate determinations as a routine, no improvement over simple unweighted least squares estimation on untransformed data suggests itself.

Evaluation of the uncertainty associated with sample holders in NAA measurements in LAN/IPEN

2019 ◽  
Vol 7 (2A) ◽  
Author(s):  
Guilherme Soares Zahn ◽  
Regina Beck Ticianelli ◽  
Mitiko Saiki ◽  
Frederico Antonio Genezini
Keyword(s):  
Stainless Steel ◽  
Neutron Activation Analysis ◽  
Neutron Activation ◽  
Gamma Rays ◽  
Experimental Error ◽  
Steel Sample ◽  
Low Energy ◽  
Stainless Steel Sample ◽  
Gamma Emission ◽  
Energy Gamma

In IPEN’s Neutron Activation Laboratory (LAN/IPEN), thin stainless steel sample holders are used for gamma spectrometry in NAA measurements. This material is very practical, but its chemical composition may be troublesome, as it presents large amounts of elements with intermediate atomic number, with attenuation factors for low-energy gamma-rays that must not be neglected. In this study, count rates obtained using different sample holders were compared. To accomplish that, an Am-241 source, with 59-keV gamma emission, was used so that low-energy gamma attenuation differences can be determined. Moreover, in order to study the energy dependence of these differences, a Ho-166m source was also used. From these results, it was possible to analyze the experimental error associated to the variations between sample holders, with the aim of introducing an addictive term to the uncertainty analysis of comparative Neutron Activation Analysis results.

Stoichiometric Determination of Graphite Intercalation Compounds Using Rutherford Backscatiering Spectrometry

1983 ◽  
Vol 27 ◽  
Author(s):  
L. Salamanca-Riba ◽  
B.S. Elman ◽  
M.S. Dresselhaus ◽  
T. Venkatesan
Keyword(s):  
Experimental Error ◽  
Rutherford Backscattering Spectrometry ◽  
Rutherford Backscattering ◽  
Intercalation Compounds ◽  
Graphite Intercalation Compounds ◽  
X Ray ◽  
Donor And Acceptor ◽  
Graphite Intercalation ◽  
Non Destructive

ABSTRACTRutherford backscattering spectrometry (RBS) is used to characterize the stoichiometry of graphite intercalation compounds (GIC). Specific application is made to several stages of different donor and acceptor compounds and to commensurate and incommensurate intercalants. A deviation from the theoretical stoichiometry is measured for most of the compounds using this non-destructive method. Within experimental error, the RBS results agree with those obtained from analysis of the (00ℓ) x-ray diffractograms and weight uptake measurements on the same samples.

Money growth variability and output: evidence with credit card-augmented Divisia monetary aggregates

2020 ◽  
Vol 24 (5) ◽  
Author(s):  
Jinan Liu ◽  
Apostolos Serletis
Keyword(s):  
Financial Stability ◽  
Credit Card ◽  
Negative Impact ◽  
Balance Sheet ◽  
Credit Cards ◽  
Money Growth ◽  
Monetary Policies ◽  
Growth Variability ◽  
Significant Negative Impact ◽  
Growth Volatility

Abstract We reexamine the effects of the variability of money growth on output, raised by Mascaro and Meltzer (1983), in the era of the increasing use of alternative payments, such as credit cards. Using a bivariate VARMA, GARCH-in-Mean, asymmetric BEKK model, we find that the volatility of the credit card-augmented Divisia M4 monetary aggregate has a statistically significant negative impact on output from 2006:7 to 2019:3. However, there is no effect of the traditional Divisia M4 growth volatility on real economic activity. We conclude that the balance sheet targeting monetary policies after the financial crisis in 2007–2009 should pay more attention on the broad credit card-augmented Divisia M4 aggregate to address economic and financial stability.

scholarly journals Louvain Natural Radiocarbon Measurements X

Radiocarbon ◽  
1971 ◽  
Vol 13 (1) ◽  
pp. 45-51 ◽  
Author(s):  
E. Gilot
Keyword(s):  
Half Life ◽  
Experimental Error

The following list comprises measurements made during 1969–70. The method is essentially the same as previously described, using a 0.6 L proportional gas-counter at 3 atm CH4 pressure. Ages are calculated with a half-life of 5570 yr and quoted with 1σ experimental error. Descriptions and comments are based on information supplied by the submitters.

Critical constants and density dependence of the Lorenz–Lorentz coefficient for germane

1978 ◽  
Vol 56 (9) ◽  
pp. 1140-1141 ◽  
Author(s):  
P. Palffy-Muhoray ◽  
D. Balzarini
Keyword(s):  
Critical Temperature ◽  
Density Dependence ◽  
Experimental Error ◽  
Critical Density ◽  
Coexistence Curve ◽  
Index Of Refraction ◽  
Density Range ◽  
Temperature Range ◽  
Critical Constants

The index of refraction at 6328 Å has been measured for germane in the density range 0.15 to 0.9 g/cm3. The temperature and density ranges over which measurements are made are near the coexistence curve. The coefficient in the Lorenz–Lorentz expression, [Formula: see text], is constant to within 0.5% within experimental error for the temperature range and density range studied. The coefficient is slightly higher near the critical density. The critical density is measured to be 0.503 g/cm3. The critical temperature is measured to be 38.92 °C.

Thermodynamics of sublimation of cubane: natural anomaly or experimental error?

2003 ◽  
Vol 408 (1-2) ◽  
pp. 115-121 ◽  
Author(s):  
Vladimir V Diky ◽  
Michael Frenkel ◽  
Larisa S Karpushenkava
Keyword(s):  
Experimental Error

BASIS FOR SYNTHESIS OF SPIRAL LATTICE QUASICRYSTALS

1989 ◽  
Vol 03 (14) ◽  
pp. 1071-1085 ◽  
Author(s):  
L. A. BURSILL ◽  
GEORGE RYAN ◽  
XUDONG FAN ◽  
J. L. ROUSE ◽  
JULIN PENG ◽  
...  
Keyword(s):  
Experimental Error ◽  
Theoretical Models ◽  
Cell Number ◽  
Close Packing ◽  
Helianthus Tuberosus ◽  
Lucas Numbers ◽  
Average Growth ◽  
Left And Right ◽  
Seed Cell ◽  
Fibonacci And Lucas Numbers

Observations of the sunflower Helianthus tuberosus reveal the occurrence of both Fibonacci and Lucas numbers of visible spirals (parastichies). This species is multi-headed, allowing a quantitative study of the relative abundance of these two types of phyllotaxis. The florets follow a spiral arrangement. It is remarkable that the Lucas series occurred, almost invariably, in the first-flowering heads of individual plants. The occurrence of left-and right-handed chirality was found to be random, within experimental error, using an appropriate chirality convention. Quantitative crystallographic studies allow the average growth law to be derived (r = alτ−1; θ = 2πl/(τ + 1), where a is a constant, l is the seed cell number and τ is the golden mean [Formula: see text]). They also reveal departures from classical theoretical models of phyllotaxis, taking the form of persistent oscillations in both divergence angle and radius. The experimental results are discussed in terms of a new theoretical model for the close-packing of growing discs. Finally, a basis for synthesis of (inorganic) spiral lattice structures is proposed.

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