Aerospace Size Standard for O-Rings

2020 ◽  
Author(s):  
Keyword(s):  
Size Standard

scholarly journals The Sampling Distribution of Disease-Associated Alleles

Genetics ◽  
1997 ◽  
Vol 147 (4) ◽  
pp. 1855-1861 ◽  
Author(s):  
Montgomery Slatkin ◽  
Bruce Rannala
Keyword(s):  
Low Frequency ◽  
Null Model ◽  
Sampling Distribution ◽  
Death Process ◽  
Published Data ◽  
Data Sets ◽  
Likelihood Functions ◽  
Alternative Hypotheses ◽  
Size Standard ◽  
Birth Death

Abstract A theory is developed that provides the sampling distribution of low frequency alleles at a single locus under the assumption that each allele is the result of a unique mutation. The numbers of copies of each allele is assumed to follow a linear birth-death process with sampling. If the population is of constant size, standard results from theory of birth-death processes show that the distribution of numbers of copies of each allele is logarithmic and that the joint distribution of numbers of copies of k alleles found in a sample of size n follows the Ewens sampling distribution. If the population from which the sample was obtained was increasing in size, if there are different selective classes of alleles, or if there are differences in penetrance among alleles, the Ewens distribution no longer applies. Likelihood functions for a given set of observations are obtained under different alternative hypotheses. These results are applied to published data from the BRCA1 locus (associated with early onset breast cancer) and the factor VIII locus (associated with hemophilia A) in humans. In both cases, the sampling distribution of alleles allows rejection of the null hypothesis, but relatively small deviations from the null model can account for the data. In particular, roughly the same population growth rate appears consistent with both data sets.

Effect Size Standard Errors for the Non-Normal Non-Identically Distributed Case

1986 ◽  
Vol 11 (4) ◽  
pp. 293 ◽  
Author(s):  
Hoben Thomas
Keyword(s):  
Effect Size ◽  
Standard Errors ◽  
Size Standard

Male reproductive behaviour and spawning success in a temperate zone goby, Coryphopterus nicholsi

1982 ◽  
Vol 60 (10) ◽  
pp. 2309-2316 ◽  
Author(s):  
Kathleen S. Cole
Keyword(s):  
Reproductive Success ◽  
Standard Length ◽  
Reproductive Behaviour ◽  
Reproductive Season ◽  
Temperate Zone ◽  
Testicular Development ◽  
Male Size ◽  
Size Standard ◽  
Highly Correlated ◽  
Spawning Success

Coryphopterus nicholsi is a temperate zone marine goby. In laboratory groups of fish, females preferentially spawn with dominant males; assessment of dominance appears to be based upon courting vigour. Male size (standard length) and dominance were often, but not always, highly correlated. In contrast, there was no consistent correlation between territorial quality and spawning success. Smaller males in laboratory groups did not court females or guard eggs. However, their behaviour and testicular development during the reproductive season suggest that they may engage in sneak spawning. Dominant males are more likely to successfully guard eggs against conspecific predators than are subordinate males, and hence females should have greater reproductive success if they choose dominant males for spawning partners.

The Effects of Acute Exercise on Retroactive Memory Interference

2019 ◽  
Vol 34 (1) ◽  
pp. 25-31 ◽  
Author(s):  
Paul D. Loprinzi ◽  
Emily Frith ◽  
Lindsay Crawford
Keyword(s):  
Acute Exercise ◽  
Experimental Studies ◽  
Memory Task ◽  
Word List ◽  
Moderate Intensity ◽  
Long Term Memory ◽  
Memory Interference ◽  
Standard Difference ◽  
Size Standard ◽  
List Memory

Purpose: Retroactive interference involves the disruption of previously encoded information from newly learned information and thus may impair the consolidation of long-term memory. The objective of this study was to evaluate whether acute exercise can attenuate retroactive memory interference. Design: Three experimental studies were employed. Experiment 1 employed a between-subject randomized control trial (RCT) involving moderate-intensity walking (15 minutes). Experiment 2 employed a between-subject RCT involving high-intensity jogging (15 minutes). Experiment 3 employed a within-subject RCT involving moderate-intensity walking (15 minutes). Setting: University setting. Participants: One hundred twelve young adults. Measures: After exercise, memory interference was evaluated from an episodic word-list memory task, involving the recall of 2 word lists. Results: The pooled effect size (standard difference in means: −0.35; 95% confidence interval: −0.64 to −0.06) across the 3 experiments was statistically significant ( P = .01). Conclusion: We provide suggestive evidence that acute, short-duration exercise may help attenuate a retroactive memory interference effect. Implications of these findings for exercise to improve memory and attenuate memory decay are discussed.

scholarly journals A Measurement Method of Microsphere with Dual Scanning Probes

2019 ◽  
Vol 9 (8) ◽  
pp. 1598 ◽  
Author(s):  
Fang ◽  
Huang ◽  
Xu ◽  
Cheng ◽  
Chen ◽  
...  
Keyword(s):  
Measurement Method ◽  
Coordinate Measuring Machine ◽  
Quartz Tuning Fork ◽  
Cross Sectional ◽  
Scanning Probes ◽  
Repeatability Error ◽  
Measurement Results ◽  
Size Standard ◽  
Measuring Machine ◽  
Tungsten Tip

The probe tip of a micro-coordinate Measuring Machine (micro-CMM) is a microsphere with a diameter of hundreds of microns, and its sphericity is generally controlled within tens to hundreds of nanometers. However, the accurate measurement of the microsphere morphology is difficult because of the small size and high precision requirement. In this study, a measurement method with two scanning probes is proposed to obtain dimensions including the diameter and sphericity of microsphere. A series of maximum cross-sectional profiles of the microsphere in different angular directions are scanned simultaneously and differently by the scanning probes. By integrating the data of these maximum profiles, the dimensions of the microsphere can be calculated. The scanning probe is fabricated by combining a quartz tuning fork and a tungsten tip, which have a fine vertical resolution at a sub-nano scale. A commercial ruby microsphere is measured with the proposed method. Experiments that involve the scanning of six section profiles are carried out to estimate the dimensions of the ruby microsphere. The repeatability error of one section profile is 15.1 nm, which indicates that the measurement system has favorable repeatability. The mainly errors in the measurement are eliminated. The measured diameter and roundness are all consistent with the size standard of the commercial microsphere. The measurement uncertainty is evaluated, and the measurement results show that the method can be used to measure the dimensions of microspheres effectively.

A simple and inexpensive method for producing fluorescently labelled size standard

2004 ◽  
Vol 4 (4) ◽  
pp. 768-771 ◽  
Author(s):  
V. VAUGHAN SYMONDS ◽  
ALAN M. LLOYD
Keyword(s):  
Inexpensive Method ◽  
Size Standard

Aerospace Size Standard for Oversize O-rings

2019 ◽  
Author(s):  
Keyword(s):  
Size Standard

Aerospace Size Standard for O-Rings

10.4271/as568 ◽  
1971 ◽  
Author(s):  
Keyword(s):  
Size Standard

Characterization of LDMMs

MRS Bulletin ◽  
1990 ◽  
Vol 15 (12) ◽  
pp. 41-43
Keyword(s):  
Spatial Scale ◽  
Cell Size ◽  
Three Dimensional ◽  
Morphological Properties ◽  
Sem Images ◽  
Average Cell Size ◽  
Cell Size Distribution ◽  
Average Cell ◽  
Process Step ◽  
Size Standard

The previous sections of this article described the synthesis, morphologies, and properties of a variety of low-density microcellular materials. This section discusses several of the analytical methods used and developed at the DOE laboratories to characterize these state-of-the-art materials.In some LDMM applications, quantitative measurements of the material's average cell size and cell size distribution are desired. Indeed, the term “microcellular” has little meaning without such information. As seen throughout this article, however, most LDMMs do not have a readily defined cellular character. The more general problem is to quantify the spatial scale(s) of the foam. For this purpose it is necessary to define one or more “measures” of the spatial scale. The possibilities are many and include not only single numbers (e.g., cell size and cell size standard deviation, where “cell size” is meaningful) but also functional descriptions (e.g., correlation functions).SEM provides direct images and, therefore, is the most popular technique for examining LDMM morphology. SEM, however, suffers from at least three limitations: (1) SEM examines only a very small volume of material, and thus is impractical for obtaining average morphological properties; (2) SEM requires that nonconductive LDMMs be coated, a process step that can alter the structure and introduce artifacts (particularly with delicate structures); and (3) SEM images are only two-dimensional projections of real three-dimensional structures.

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