Probabilistic Properties of Steel for Nuclear Piping

2018 ◽  
Author(s):  
Kleio Avrithi
Keyword(s):  
Mean Value ◽  
Background Information ◽  
Low Alloy Steels ◽  
Target Reliability Index ◽  
Alloy Steels ◽  
Factor Design ◽  
The Mean ◽  
Materials Used ◽  
Load And Resistance Factor ◽  
The Impact

For the development of design rules for nuclear piping using the Load and Resistance Factor Design (LRFD) method, the probabilistic properties of steel, namely, the mean value, bias, coefficient of variation, and probability distribution are needed. The paper presents background information for the existing material tables in the ASME Boiler and Pressure Vessel Code, Section II. Then it investigates the probabilistic properties for the most representative materials used for nuclear piping such as a carbon, stainless austenitic, and low alloy steels. Properties up to temperature 700°F are examined through a review of studies for the mechanical behavior of these materials. The paper discusses approaches for grouping materials in broader categories than the consideration of each type of steel separately. The impact of the steel probabilistic properties on the development of LRFD equations and the associated target reliability index is provided.

On the Material Properties for Piping Load and Resistance Factor Design

2021 ◽  
Author(s):  
Kleio Avrithi
Keyword(s):  
Reliability Index ◽  
Room Temperature ◽  
Mean Value ◽  
Resistance Factor ◽  
Low Alloy Steel ◽  
Factor Design ◽  
The Mean ◽  
Load And Resistance Factor ◽  
The Impact ◽  
Steel Properties

Abstract The probabilistic properties of steel, namely the mean value, coefficient of variation, and probability distribution are needed for the development of Load and Resistance Factor Design (LRFD) equations for Class 2 and 3 nuclear piping and for probabilistic and risk analysis studies. This work investigates the probabilistic properties for the most representative steels used for nuclear piping, such as carbon, stainless austenitic, and low alloy. Steel properties at room temperature and up to temperature 700oF are examined through reported mechanical behavior. The work concludes with the impact of the stainless steels' probabilistic properties on the reliability index or else probability of failure for the piping. The presented data can help organize steel materials for LRFD and reduce the variability of the reliability index.

Materials for bullet core

2020 ◽  
Vol 2020 (10) ◽  
pp. 8-21
Author(s):  
A. G. Kolmakov ◽  
◽  
I. O. Bannykh ◽  
V. I. Antipov ◽  
L. V. Vinogradov ◽  
...  
Keyword(s):  
High Speed ◽  
Bending Strength ◽  
Low Alloy Steels ◽  
Hard Alloys ◽  
Small Arms ◽  
Alloy Steels ◽  
Materials Used ◽  
Basic Ideas ◽  
New Generation ◽  
Natural Composite

he basic ideas about the process of introducing cores into protective barriers and the most common core patterns and their location in conventional and sub-caliber small arms bullets are discussed. The materials used for manufacture of cores are analyzed. It is concluded that for mass bullets of increased armor penetration the most rational choice can be considered the use of high-carbon low-alloy steels of a new generation with a natural composite structure and hardness of up to 70 HRC. For specialized armor-piercing bullets, cores made from promising economically-alloyed high-speed steels characterized by a high complex of «hardness—bending strength» are better alternative than ones made of hard alloys or tungsten alloys.

Study of hydrogenation and corrosion of steel equipment and pipelines at the production facilities of H2S -containing hydrocarbon raw materials

2021 ◽  
pp. 170-181
Author(s):  
R. K. Vagapov
Keyword(s):  
Raw Materials ◽  
Strength Properties ◽  
Point Of View ◽  
Low Alloy Steels ◽  
Safety And Reliability ◽  
Alloy Steels ◽  
Steel Equipment ◽  
Equipment And Pipelines ◽  
Corrosion Of Steel ◽  
The Impact

The impact of hydrogen sulfide raw materials on steel equipment and pipelines is associated not only with corrosion processes, but also with the hydrogenation of used carbon and low-alloy steels. This can lead to the loss of their strength properties and the subsequent destruction of equipment operated under conditions of increased operating pressures. Such corrosive-mechanical effects associated with the penetration of hydrogen into steel are the most dangerous from the point of view of the safety and reliability of the operation of facilities for the production of hydrocarbon fluids. The effect of H2S on the main types of structural steels was investigated according to the results of autoclave tests. The formation of blistering (blistering) and cracks on the surface of steels due to the effect of hydrogen on the steel was recorded. A study of the phase composition of corrosion products and their possible effect on the processes of corrosion and hydrogenation of steel has been carried out.

scholarly journals Perturbation analysis of a variable M/M/1 queue: a probabilistic approach

2006 ◽  
Vol 38 (01) ◽  
pp. 263-283 ◽  
Author(s):  
Nelson Antunes ◽  
Christine Fricker ◽  
Fabrice Guillemin ◽  
Philippe Robert
Keyword(s):  
Power Series ◽  
Busy Period ◽  
Stationary Process ◽  
Probabilistic Approach ◽  
Power Series Expansion ◽  
Mean Value ◽  
Service Rate ◽  
The Mean ◽  
The Impact ◽  
Period Duration

In this paper, motivated by the problem of the coexistence on transmission links of telecommunications networks of elastic and unresponsive traffic, we study the impact on the busy period of an M/M/1 queue of a small perturbation in the service rate. The perturbation depends upon an independent stationary process (X(t)) and is quantified by means of a parameter ε ≪ 1. We specifically compute the two first terms of the power series expansion in ε of the mean value of the busy period duration. This allows us to study the validity of the reduced service rate approximation, which consists in comparing the perturbed M/M/1 queue with the M/M/1 queue whose service rate is constant and equal to the mean value of the perturbation. For the first term of the expansion, the two systems are equivalent. For the second term, the situation is more complex and it is shown that the correlations of the environment process (X(t)) play a key role.

scholarly journals THE LUCK IN “TALENT VERSUS LUCK” MODELING

2020 ◽  
Vol 23 (03) ◽  
pp. 2050007
Author(s):  
SEAN ELVIDGE
Keyword(s):  
Mean Value ◽  
Maximum Amount ◽  
Random Numbers ◽  
Individual Parameter ◽  
Input Parameters ◽  
The Mean ◽  
Model Variability ◽  
The Impact ◽  
The Relationship

This paper further investigates the Talent versus Luck (TvL) model described by [Pluchino et al. Talent versus luck: The role of randomness in success and failure, Adv. Complex Syst. 21 (2018) 1850014] which models the relationship between ‘talent’ and ‘luck’ on the impact of an individuals career. It is shown that the model is very sensitive to both random sampling and the choice of value for the input parameters. Running the model repeatedly with the same set of input parameters gives a range of output values of over 50% of the mean value. The sensitivity of the inputs of the model is analyzed using a variance-based approach based upon generating Sobol sequences of quasi-random numbers. When using the model to look at the talent associated with an individual who has the maximum capital over a model run it has been shown that the choice for the standard deviation of the talent distribution contributes to 67% of the model variability. When investigating the maximum amount of capital returned by the model the probability of a lucky event at any given epoch has the largest impact on the model, almost three times more than any other individual parameter. Consequently, during the analysis of the model results one must keep in mind the impact that only small changes in the input parameters can have on the model output.

​Impact of Extreme Hot Environmental Temperature Period on Marker Enzymes of Carbohydrate Metabolism in Non-descript Sheep from Arid Tracts of Rajasthan

2021 ◽  
Author(s):  
Anandita Srivastava ◽  
Nalini Kataria
Keyword(s):  
Carbohydrate Metabolism ◽  
Environmental Temperature ◽  
Age Groups ◽  
Extreme Temperature ◽  
Mean Value ◽  
Marker Enzymes ◽  
Mean Values ◽  
The Mean ◽  
The Impact ◽  
Enzymes Of Carbohydrate Metabolism

Background: The present investigation was envisaged to find out the impact of extreme hot environmental temperature period (ETP) on marker enzymes of carbohydrate metabolism in male and female non-descript sheep of various age groups i.e. 4 to 13 months from arid tracts of Rajasthan. Glucose-6-phosphate dehydrogenase (G-6-PDH) and malate dehydrogenase (MDH) marker enzymes of carbohydrate metabolism were considered for study. Methods: During the period October 2016-June 2017 blood samples were collected to harvest sera for spectrophotometric method from 240 healthy animals selected from private slaughter house during moderate and extreme hot environmental temperature periods (ETPs). The mean values of markers attained during moderate ETP were reckoned as the control. It was 10.00 ± 0.10 UL-1 and 42.00±1.00 respectively. Conclusion: The mean value of MDH was significantly (p≤0.05) higher while G-6-PDH significantly (p≤0.05) lowers during extreme hot temperature in comparison to moderate period. Therefore, it could be concluded that variations in enzyme markers were associated with changes in environmental temperatures. Probably ETP were able to produce a profound effect on carbohydrate metabolism in sheep. Therfore it can be suggested that during the period of extreme temperature balanced ration must be provided to the animal along with proper management to decrease the severity of temperature impact.

KUALITAS HIDUP REMAJA YANG MENGALAMI DISMENORE DI SMK NEGERI 2 SUMEDANG

2018 ◽  
Vol 4 (2) ◽  
pp. 129
Author(s):  
Nadya Puspita Dewi ◽  
Tetti Solehati ◽  
Nur Oktavia Hidayati
Keyword(s):  
Quality Of Life ◽  
Sampling Technique ◽  
Mean Value ◽  
Social Dimension ◽  
Validity And Reliability ◽  
School Activities ◽  
Emotional Dimension ◽  
The Mean ◽  
The Impact

Dysmenorrhea is a pain before or during the menstrual period. The impact of dysmenorrhea are the disruption on physical function, emotional, social and school activities and disruption of quality of life. The study purpose is to detect the quality of life of adolescents with dysmenorrhea.The research method was a quantitative descriptive with total sampling technique to 195 students which selected using dysmenorrhea screening. The data were collected using the pediatric quality of life 4.0 generic module (PedsQL) teens report in Indonesian version which the validity and reliability have been tested. Analysis of data has been done to find out the mean value in each dimension and frequency distribution. The results showed that the mean value of the quality of life of adolescents with dysmenorrhea in general was 62,04 ± 8,15 and 51,8% was in the low. The mean value in physical dimension was 49,36 ± 9,19, emotional dimension was 57,62 ± 13,16, social dimension was 86,38 ± 13,28, and in the school dimension was 62,41 ± 14,77. The quality of life in high categories were in the emotional dimension (60,0%), social dimension (64,1%), and school dimension (60,5%). Meanwhile, the quality of life in low category was in the physical dimension (57,4%). It showed that the quality of life of adolescents with dysmenorrhea in SMK Negeri 2 Sumedang were low. It was recommended to the school and the health office in Sumedang district to provide the reproductive health education, specifically about the prevention and the treatment of dysmenorrhea on adolescents.  

Mindfulness and insomnia at pregnancy

2016 ◽  
Vol 33 (S1) ◽  
pp. s269-s269
Author(s):  
M. Marques ◽  
A.T. Pereira ◽  
E. Bento ◽  
S. Xavier ◽  
J. Azevedo ◽  
...  
Keyword(s):  
Anxiety Disorders ◽  
Pregnant Women ◽  
Mean Value ◽  
Inner Experience ◽  
The Mean ◽  
Competing Interest ◽  
Acting With Awareness ◽  
The Impact ◽  
Insomnia Symptoms ◽  
In Pregnancy

IntroductionThe impact of mindfulness in improving insomnia symptoms is documented in different samples (e.g. anxiety disorders; insomnia samples) and mindfulness based programs for pregnancy refer the association between mindfulness development and the reduction of insomnia symptoms/improvement of sleep.ObjectiveTo explore differences in the Facets Mindfulness Questionnaire-10 (FMQ-10; Azevedo et at. 2015), between sleep groups, in Portuguese pregnant women.MethodsFour hundred and nineteen pregnant women (mean age: 32.51 ± 4.759; weeks of gestation: 17.32 ± 4.803) answered the Facets Mindfulness Questionnaire-10 and the Insomnia Assessment Scale (IAS, Marques et al., 2015). Three sleep groups were created considering all the IAS items: good sleepers (no insomnia symptoms; no associated daily impairment); insomnia symptoms groups (one/more insomnia symptoms; no associated daily impairment; exclusion of other conditions/disorders explaining the symptoms); insomniacs (one/more insomnia symptoms; one/more daily associated impairment; exclusion of other conditions/disorders explaining the symptoms).ResultsThere were significant differences in the total FMQ-10 score, the F1/Nonjudging of inner experience and the F2/acting with awareness, between sleep groups [respectively, F (2.402) = 6,933; P = 0.001; F (2.406) = 10.243; P = 0.001; F (2.406) = 37.431; P = 0.002]. Tukey tests indicated that the mean total FMQ-10 and F1/Nonjudging of inner experience scores of good sleepers and insomnia symptoms group were significantly higher than of the insomniacs. The mean value of F2/acting with awareness in the good sleepers was significantly higher than of the insomniacs.ConclusionsIt seems important to develop mindfulness to improve sleep in pregnancy or reduce the impact of insomnia symptoms (common at pregnancy).Disclosure of interestThe authors have not supplied their declaration of competing interest.

Assessing the Target Reliability Index for Nuclear Piping

2016 ◽  
Author(s):  
Kleio Avrithi
Keyword(s):  
Reliability Index ◽  
Historical Data ◽  
Allowable Stress ◽  
Safety Factors ◽  
Code Calibration ◽  
Target Reliability Index ◽  
Consistent Manner ◽  
Factor Design ◽  
Load And Resistance Factor ◽  
Allowable Stress Design

Previous research developed Load and Resistance Factor Design (LRFD) equations for Class 2 and 3 nuclear piping for different reliability levels and load combinations. The LRFD equations consider separate safety factors for each load and for the strength of steel in opposition to the Allowable Stress Design (ASD) equations used in the ASME Boiler and Pressure Vessel (B&PV) Code, Section III, Div. 1, where only one safety factor is considered. In order to use the developed LRFD equations for the design of nuclear piping, specific reliability levels or else acceptable probabilities of failure need to be assigned to each Code equation. The paper discusses the available methods for evaluating the target reliability index, such as historical data of piping failures, expert-opinion elicitation, and Code calibration. Code calibration is the method of determining the existing level of reliability in the Code equations and assigning the same reliability to the developed LRFD equations in a consistent manner. Code Calibration is explained to be the more appropriate method of assigning reliability levels to the LRFD equations. The other methods can supplement the analysis results.

A Study of Ecological Water Use Based on the Improved Tennant Method

2010 ◽  
Vol 113-116 ◽  
pp. 1504-1508 ◽  
Author(s):  
Jing Huan Tian ◽  
Ling Yu ◽  
Zhi Hong Zheng
Keyword(s):  
Water Use ◽  
Traditional Method ◽  
Extreme Values ◽  
Mean Value ◽  
Improved Method ◽  
Existing Problems ◽  
Runoff Series ◽  
Tennant Method ◽  
The Mean ◽  
The Impact

To solve the existing problems arose in the Tennant method for estimating ecological water use in river course, a new methodology is proposed to replace the mean value by the median of runoff series in the Tenna nt formula. The motive is to eliminate the impact of some extreme values. Given runoff series of 47 years in Jiaokou reservoir of Zhangxi River, the traditional and the improved method were respectively applied to calculate the ecological water consumption in the river. The results show that the improved Tennant method is more reasonably than the traditional method.

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