scholarly journals Measurement of the average lifetime of hadrons containing bottom quarks

1988 ◽  
Vol 37 (1) ◽  
pp. 41-51 ◽  
Author(s):  
D. E. Klem ◽  
W. B. Atwood ◽  
B. C. Barish ◽  
G. R. Bonneaud ◽  
A. Courau ◽  
...  
1998 ◽  
Vol 38 (6) ◽  
pp. 209-217 ◽  
Author(s):  
Jianhua Lei ◽  
Sveinung Sægrov

This paper demonstrates the statistical approach for describing failures and lifetimes of water mains. The statistical approach is based on pipe inventory data and the maintenance data registered in the data base. The approach consists of data pre-processing and statistical analysis. Two classes of statistical models are applied, namely counting process models and lifetime models. With lifetime models, one can estimate the probability which a pipe will fail within a time horizon. With counting process models one can see the deteriorating (or improving) trend in time of a group of “identical” pipes and their rates of occurrence of failure (ROCOF). The case study with the data base from Trondheim municipality (Norway) demonstrates the applicability of the statistical approach and leads to the following results: 1). In the past 20 years, Trondheim municipality has experienced approximately 250 to 300 failures per year. However, the number of failures per year will significantly increase in the near future unless better maintenance practice is implemented now. 2). Unprotected ductile iron pipes have a higher probability of failures than other materials. The average lifetime of unprotected ductile iron pipes is approximately 30 to 40 years shorter than the lifetime of a cast iron pipe. 3). Pipes installed 1963 and 1975 are most likely to fail in the future; 4) The age of a pipe does not play a significant role for the remaining lifetime of the pipe; 5). After 2 to 3 failures, a pipe enters a fast-failure stage (i.e., frequent multiple between failures).


Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2788
Author(s):  
Xiaozhou Fan ◽  
Wenqi Zhang ◽  
Fangcheng Lü ◽  
Yueyi Sui ◽  
Jiaxue Wang ◽  
...  

Fluorescent optical fiber temperature sensors have attracted extensive attention due to their strong anti-electromagnetic interference ability, good high-voltage insulation performance, and fast response speed. The fluorescent material of the sensor probe directly determines the temperature measurement effect. In this paper, a new type of fluorescent material with a Mn2+-doped Ca2SiO4 phosphor (CSO:Mn2+) is synthesized via the solid-state reaction method at 1450 °C. The X-ray diffraction spectrum shows that the sintered sample has a pure phase structure, although the diffraction peaks show a slight shift when dopants are added. The temperature dependence of the fluorescence intensity and lifetime in the range from 290 to 450 K is explored with the help of a fluorescence spectrometer. Green emission bands peaking at 475 and 550 nm from Mn2+ are observed in the fluorescence spectra, and the intensity of emitted light decreases as the temperature rises. The average lifetime of CSO:Mn2+ is 17 ms, which is much higher than the commonly used fluorescent materials on the market. The fluorescence lifetime decreases with increasing temperature and shows a good linear relationship within a certain temperature range. The research results are of great significance to the development of a new generation of fluorescence sensors.


2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Gauthier Durieux ◽  
Adrian Irles ◽  
Víctor Miralles ◽  
Ana Peñuelas ◽  
Martín Perelló ◽  
...  

In the course of follow-up work a mistake was discovered in the parameterization of the dependence of the W-boson helicity fractions in top quark decays. The dependence on two operator coefficients, Cφtb and CbW, was erroneously omitted. Inclusion of this dependence leads to significantly stronger bounds on these operators from the current data and modifies also the HL-LHC prospects. The expectations for e+e− colliders are not affected. We present corrected results in this erratum.


2014 ◽  
Vol 2014 (3) ◽  
Author(s):  
M. Gillioz ◽  
R. Gröber ◽  
A. Kapuvari ◽  
M. Mühlleitner

Energies ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3801 ◽  
Author(s):  
Ahmed Raza ◽  
Vladimir Ulansky

Among the different maintenance techniques applied to wind turbine (WT) components, online condition monitoring is probably the most promising technique. The maintenance models based on online condition monitoring have been examined in many studies. However, no study has considered preventive maintenance models with incorporated probabilities of correct and incorrect decisions made during continuous condition monitoring. This article presents a mathematical model of preventive maintenance, with imperfect continuous condition monitoring of the WT components. For the first time, the article introduces generalized expressions for calculating the interval probabilities of false positive, true positive, false negative, and true negative when continuously monitoring the condition of a WT component. Mathematical equations that allow for calculating the expected cost of maintenance per unit of time and the average lifetime maintenance cost are derived for an arbitrary distribution of time to degradation failure. A numerical example of WT blades maintenance illustrates that preventive maintenance with online condition monitoring reduces the average lifetime maintenance cost by 11.8 times, as compared to corrective maintenance, and by at least 4.2 and 2.6 times, compared with predetermined preventive maintenance for low and high crack initiation rates, respectively.


1994 ◽  
Vol 74 (3) ◽  
pp. 401-409 ◽  
Author(s):  
D. Perotto ◽  
R. I. Cue ◽  
A. J. Lee ◽  
A. J. McAllister ◽  
J. R. Batra ◽  
...  

Crossbreeding parameters (line additive, dominance and additive × additive epistatic effects for individual and for maternal performance) on growth traits of females from a crossbreeding experiment between Holstein-based (HS) and Ayrshire-based (AS) lines were estimated by individual animal models, incorporating all known additive genetic relationships among animals, through restricted maximum likelihood and mixed-model methodologies. The growth traits [asymptotic weight (A), rate parameter (k), inflection parameter (m), average lifetime absolute growth rate (AGR), average lifetime absolute maturing rate (AMR) and average lifetime relative growth rate (RGR)] were estimated by fitting the Richards function to the observed growth curve of 3076 individuals. The statistical model included the random effect of the animal breeding value and the fixed effects of genetic group and station–year–season of birth. Results indicated that the HS exceeded (P < 0.001) the AS in additive effects for individual performance for both A and AGR. The HS exceeded (P < 0.05) the AS in additive effects for maternal performance for A. Individual heterosis was positive for A (P < 0.001) and for AGR (P < 0.01). Maternal heterosis was negative for A (P < 0.05) and positive for AMR (P < 0.05). Total heterosis (TH) had positive effects on both AGR and AMR (P < 0.05). Heterosis retained in advanced crossbred generations was not significant (P > 0.05) for any of the studied traits. The results suggest that crossbreeding designed to exploit TH can alter the shape of the growth curve of dairy cattle. Key words: Crossbreeding, dairy cattle, growth curve


1993 ◽  
Vol 71 (21) ◽  
pp. 3421-3426 ◽  
Author(s):  
F. Abe ◽  
M. Albrow ◽  
D. Amidei ◽  
C. Anway-Wiese ◽  
G. Apollinari ◽  
...  
Keyword(s):  

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