Consideration of Environmentally Assisted Fatigue in Austenitic Stainless Steel: Calculation and Practical Application

2012 ◽  
Author(s):  
Sven H. Reese ◽  
Johannes Seichter ◽  
Dietmar Klucke
Keyword(s):  
Primary Circuit ◽  
Stress And Strain ◽  
Loading Conditions ◽  
Practical Application ◽  
Circuit Component ◽  
Detailed Assessment ◽  
The Mean ◽  
Fatigue Evaluation ◽  
Assessment Procedures

The influence of LWR coolant environment to the lifetime of materials has been discussed recent years. Nowadays the consideration of environmentally assisted fatigue is under consideration in Codes and Standards like ASME and the German KTA Rules (e.g. Standard No. 3201.2 and Standard No. 3201.4) by means of so called attention thresholds. Basic calculation procedures in terms of quantifying the influence of LWR coolant environment by the Fen correction factor were proposed by Higuchi and others and are given in NUREG/CR-6909. This paper deals with the application of the proposed assessment procedures of ANL and the application to plant conditions. Therefore conservative assessment procedures are introduced without assuming the knowledge of detailed stress and strain calculations or temperature transients. Additionally, detailed assessment procedures based on Finite-Element calculations, respecting in-service temperature measurements including thermal reference transients and complex operational loading conditions are carried out. Fatigue evaluation of a PWR primary circuit component is used in order to evaluate the influence of plant like conditions numerically. Conclusions regarding the practical application are drawn by means of comparing the ANL approach considering laboratory conditions, conservative assessment procedures for the determination of cumulative fatigue usage factors of plant components and detailed assessment procedures. Plant like loading conditions, complex component geometries, loading scenarios and reference temperature transients shall be taken into account. Practical issues like the determination of the mean temperature or the strain rate have to be considered adequately.

Sophisticated Procedures for Fatigue Evaluation in the Framework of German KTA Codes

2013 ◽  
Author(s):  
Johannes Seichter ◽  
Sven H. Reese ◽  
Dietmar Klucke
Keyword(s):  
Threshold Value ◽  
Austenitic Steels ◽  
Ferritic Steels ◽  
Design Phase ◽  
Threshold Values ◽  
Detailed Evaluation ◽  
Detailed Assessment ◽  
Low Probability ◽  
Fatigue Evaluation ◽  
Assessment Procedures

German KTA consider the intensively discussed topic of environmentally assisted fatigue (EAF) by introducing so called attention thresholds for the cumulative fatigue usage factors (CUF). Threshold values for both austenitic steels and ferritic steels are defined. If the threshold value is exceeded, further measures like NDT, in-service inspections or detailed assessment procedures have to be performed. One way to handle those measures is to apply sophisticated procedures and to show that the numerically calculated CUF is below the defined attention thresholds. The article presents some examples to reduce calculated CUFs. Fatigue analyses performed during design phase of NPP are based on specified loads consisting of conservatively determined reference transients, covering the whole lifetime including events with significantly fewer cycles than assumed during design phase as well as events with very low probability of occurrence at all. But there might be also operational loads which are not included in the load specifications. In general, there is a lot of potential to reduce computed CUFs in terms of considering realistic loading scenarios. In German NPPs various temperature measurement planes are applied at fatigue relevant positions among others to calculate actual CUFs based on real loads. Detailed finite element (FE) calculations considering these loads can reduce computed CUFs considerably. Therefore detailed evaluation of temperature measurements in combination with FE calculations is carried out, reducing calculated CUFs below the threshold values given in German KTA.

Latency in onset of decompression sickness on direct ascent from air saturation

1984 ◽  
Vol 56 (4) ◽  
pp. 1070-1075 ◽  
Author(s):  
R. G. Eckenhoff ◽  
J. W. Parker
Keyword(s):  
Decompression Sickness ◽  
Human Subjects ◽  
Compressed Air ◽  
Inert Gas ◽  
Practical Application ◽  
Threshold Time ◽  
The Mean ◽  
Sufficient Magnitude ◽  
The Relationship

Twenty-four human subjects were exposed to compressed air at simulated depths ranging from 45 ft seawater gauge (fsw) (2.36 ATA) to 75 fsw (3.27 ATA) for periods of time sufficient to allow saturation of most tissues with inert gas. From each of four depths (45, 55, 65 and 75 fsw), subjects ascended directly to 1 ATA, where they remained for 30, 17, 13, and 10 min, respectively. During this time the onset of Doppler detected venous gas emboli (VGE), pruritus, and any other symptomatology was monitored and recorded. In the ascending excursion from 45 fsw (n = 18), the mean appearance times of pruritus and VGE were 19.3 +/- 7.5 (mean +/- SD) and 21.9 +/- 7.4 min, respectively, with one case of pain-only decompression sickness (DCS). The excursion from 55 fsw (n = 17) shortened these times to 9.2 +/- 3.3 and 14.4 +/- 3.2 min, respectively, with two cases of DCS, one each of pain-only and serious types. In the excursion from 65 fsw (n = 23), mean pruritus and VGE appearance times were 6.3 +/- 1.4 and 10.8 +/- 1.9 min, respectively, with no cases of DCS. The excursion from 75 fsw (n = 6) resulted in appearance times of 4.8 +/- 0.8 and 8.2 +/- 1.2, respectively, with one case of pain-only DCS. Sufficient cases of DCS did not occur in any of the excursions to allow determination of mean appearance times. The relationship between pressure reduction and appearance times of pruritus and VGE, and the threshold time of DCS, can be described mathematically. We conclude that latency in the development of DCS on direct ascent from air saturation exists and is of sufficient magnitude to permit practical application in emergency decompressions or unpressurized transfers between compressed air or N2-O2 environments.

Determination of zearalenone, deoxynivalenol and metabolites in bile of piglets fed diets with graded levels of Fusarium toxin contaminated maize

2016 ◽  
Vol 9 (2) ◽  
pp. 179-193 ◽  
Author(s):  
U. Brezina ◽  
I. Rempe ◽  
S. Kersten ◽  
H. Valenta ◽  
H.-U. Humpf ◽  
...  
Keyword(s):  
Regression Equations ◽  
Practical Application ◽  
Experimental Conditions ◽  
Internal Standards ◽  
Fusarium Toxin ◽  
The Mean ◽  
The Individual ◽  
Almost All ◽  
Bile Samples

For the simultaneous determination of zearalenone (ZEA), deoxynivalenol (DON) and their metabolites α-zearalenol (α-ZOL), β-zearalenol (β-ZOL), zearalanone (ZAN), α-zearalanol (α-ZAL), β-zearalanol (β-ZAL) and de-epoxydeoxynivalenol (DOM) in bile of piglets, a liquid chromatography with tandem mass spectrometry method including sample preparation with combined immunoaffinity columns (DZT MS-Prep®) has been developed. The analyte concentrations were determined by the use of isotopically labelled internal standards. The mean recoveries for all analytes ranged between 80 and 99%. The determined limits of detection and quantification ranged from 0.01-0.60 and 0.04-2.0 ng/ml, respectively. ZEA, DON and their metabolites were analysed in bile of female piglets fed diets containing 0.01/0.03, 0.05/0.59, 0.08/1.27, 0.17/2.01 and 0.29/4.52 mg ZEA/DON per kg during 29 days of treatment. After 1, 3, 8, 15, 22 and 29 days four piglets per group were slaughtered. ZEA, α-ZOL, β-ZOL, DON and DOM were quantified in almost all bile samples, whereas ZAN, α-ZAL and β-ZAL could only be quantified sporadically. Moreover, dose- and time-dependent effects were observed for most analytes. The toxin residues in bile correlated well with the respective mycotoxin intake per kg body weight and day and the mother toxin concentration in the diets. Due to these high correlations the exposure to dietary ZEA and DON could be predicted by the use of the corresponding regression equations. Strictly speaking these relationships are only valid for the experimental conditions of the underlying experiment. Furthermore, for practical application the individual variation need to be additionally considered.

Detection of Circulating Tissue Factor and Factor VII in a Normal Population

1996 ◽  
Vol 75 (05) ◽  
pp. 772-777 ◽  
Author(s):  
Sybille Albrecht ◽  
Matthias Kotzsch ◽  
Gabriele Siegert ◽  
Thomas Luther ◽  
Heinz Großmann ◽  
...  
Keyword(s):  
Tissue Factor ◽  
Normal Population ◽  
Mean Value ◽  
Factor Vii ◽  
Significant Difference ◽  
Age Dependent ◽  
The Mean ◽  
Highly Correlated ◽  
And Gender

SummaryThe plasma tissue factor (TF) concentration was correlated to factor VII concentration (FVIIag) and factor VII activity (FVIIc) in 498 healthy volunteers ranging in age from 17 to 64 years. Immunoassays using monoclonal antibodies (mAbs) were developed for the determination of TF and FVIIag in plasma. The mAbs and the test systems were characterized. The mean value of the TF concentration was 172 ± 135 pg/ml. TF showed no age- and gender-related differences. For the total population, FVIIc, determined by a clotting test, was 110 ± 15% and the factor VIlag was 0.77 ± 0.19 μg/ml. FVII activity was significantly increased with age, whereas the concentration demonstrated no correlation to age in this population. FVII concentration is highly correlated with the activity as measured by clotting assay using rabbit thromboplastin. The ratio between FVIIc and FVIIag was not age-dependent, but demonstrated a significant difference between men and women. Between TF and FVII we could not detect a correlation.

Determination of Plasminogen in Clots and Thrombi

1966 ◽  
Vol 16 (01/02) ◽  
pp. 038-050 ◽  
Author(s):  
Ulla Hedner ◽  
Inga Marie Nilsson ◽  
B Robertson
Keyword(s):  
Mean Value ◽  
Main Mechanism ◽  
Clot Lysis ◽  
Post Mortem ◽  
Digestion Time ◽  
Normal Volunteers ◽  
Casein Solution ◽  
The Mean

SummaryThe plasminogen content was determined by a casein method in plasma and serum from 20 normal volunteers. The mean plasminogen content was found to be 10.1 ACU (the arbitrary caseinolytic unit defined in such a way that using a 3% casein solution and a digestion time of 20 min. at 37°C, 10 ACU gave an extinction of 0.300). No difference between serum and plasma regarding the plasminogen content was found.Plasminogen was determined in drained and drained plus washed clots prepared from 2 ml plasma. The highest values found in the drained clots were 0.9 ACU/clot and 0.2 ACU/clot in the drained plus washed clots.Plasminogen was also determined in drained and drained plus washed clots prepared from plasma with added purified plasminogen. The plasminogen was recovered in the washing fluid. According to these tests, then, purified added plasminogen is washed out of the clots.The plasminogen content of 20 thrombi obtained post mortem was also determined. The mean value was found to be 0.7 ACU/cm thrombus. Judging from our results, the “intrinsic clot lysis theory” is not the main mechanism of clot dissolution.

EVALUATION OF HYSTEROSALPINGOGRAPHY VERSUS LAPAROSCOPY IN THE DETERMINATION OF TUBAL FACTORS IN FEMALE INFERTILITY: A HOSPITAL BASED COMPARATIVE STUDY.

2020 ◽  
Vol 4 (9) ◽  
Author(s):  
Richa Choudhary ◽  
Rishikant Sinha
Keyword(s):  
Female Infertility ◽  
Diagnostic Methods ◽  
Panoramic View ◽  
Tubal Patency ◽  
Pelvic Organs ◽  
Clinical Investigations ◽  
Detailed Assessment ◽  
Reproductive Anatomy ◽  
Tubal Pathology

Objectives: Hysterosalpingography and laparoscopy both are the diagnostic methods for assessment of female infertility.  The present study was to compare the evaluation of hysterosalpingography (HSG) versus laparoscopy in determination of tubal factors in female infertility. Methods: Detailed assessment, physical examination and clinical investigations were performed in all 100 infertile female with age 20 years to 40 years. All patients were advised to perform digital HSG. Patients with an abnormal HSG underwent laparoscopy without delay, whereas in patients with a normal HSG, laparoscopy was performed three months after HSG. HSG is best scheduled during the 2nd -5th day interval immediately following the end of menstruation, to minimize risk for infection, avoid interference from intrauterine blood and clot, and to prevent any possibility that the procedure might be performed after conception. Results: Data was analysed by using IBM SPSS version 23 software.  All data was tabulated and percentages were calculated. Mean ± standard deviation was observed. Conclusions: Diagnostic laparoscopy is the gold standard in diagnosing tubal pathology and other intra-abdominal causes of infertility. Other hand, Hysterosalpingography is a frequently utilized diagnostic tool in the assessment of tubal status and detection of uterine anatomical defects in infertility. Hysterosalpingography and laparoscopy are not alternatives but complimentary investigations. But, inadequacy of hysterosalpingography (HSG) in determining the state of tubal patency, emphasizes the need for laparoscopy. Laparoscopy provides both a panoramic view of the pelvic reproductive anatomy and a magnified view of pelvic organs and peritoneal surfaces. Keywords: Female infertility, Tubal patency, HSG, Laparoscopy

SERUM TRIIODOTHYRONINE DETERMINATION BY SATURATION ANALYSIS

1973 ◽  
Vol 72 (4) ◽  
pp. 714-726 ◽  
Author(s):  
A. Burger ◽  
B. Miller ◽  
C. Sakoloff ◽  
M. B. Vallotton
Keyword(s):  
Ionic Strength ◽  
Limit Of Detection ◽  
Improved Method ◽  
Accuracy Of Measurement ◽  
Tracer Amount ◽  
The Mean ◽  
Physiological Values ◽  
Hyperthyroid Patients ◽  
Solvent Blank

ABSTRACT An improved method for the determination of serum triiodothyronine (T3) has been developed. After addition of a tracer amount of the hormone, T3 was extracted from 1 ml serum under conditions of pH and ionic strength which favoured T3 extraction (89%) over thyroxine (T4) extraction (58%). Chromatography of the extracted material on Sephadex LH-20 separated T3 completely from residual T4. The T3 eluate was dried, then re-dissolved in 0.5 ml NaOH 0.04 n. To 0.2 ml duplicate aliquots, a standard amount of TBG was added for the competitive protein analysis. After one hour incubation at 4°C, separation of bound from free T3 was achieved on small Sephadex G-25 columns. Overall recovery was 67 ± 10.8% and correction for the loss was made. The solvent blank was 37 ± 27 (sd) ng/100 ml. Accuracy of measurement of known quantities of T3 added to serum was 98.4%. The coefficient of variation within the assay was 6.2% and between the assays it was 11.4%. The limit of detection (0.1 ng) corresponded to a concentration of 25 ng/100 ml. T4 added to serum did not interfere with T3 determination until high non-physiological values were reached. The mean ± sd serum T3 in 54 euthyroid subjects was 153 ± 58 ng/100 ml and in 24 hyperthyroid patients it was 428 ±186 ng/100 ml; 4 out of the 24 hyperthyroid values were within 2 sd of the mean euthyroid group. All the values found in the euthyroid group were well above the limit of detection of the method.

Germination and initial growth of triticale seeds under stationary magnetic fields

2014 ◽  
Vol 2 (2) ◽  
pp. 72-79 ◽  
Author(s):  
Mercedes Florez ◽  
Elvira Martinez ◽  
Victoria Carbonell
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Seed Vigor ◽  
Initial Growth ◽  
Practical Application ◽  
Biochemical Processes ◽  
Mean Germination Time ◽  
Nutrition Value ◽  
The Mean ◽  
Growth Of Seedlings

The main objective of this study is to determine the effects of 125 mT and 250mT magnetic treatment on the germination and initial growth of triticale seeds. This objective has a practical application in agriculture science: early growth of triticale. An increase in the percentage and rate of germination of seeds and a stimulation of growth of seedlings as positive response to magnetic field treatment in rice, wheat, maize and barley seeds have been found in previous studies. Germination tests were carried out under laboratory conditions by exposing triticale seeds to magnetic field for different times. The effect was studied by exposure of seeds prior sowing. The mean germination time were reduced for all the magnetic treatments applied. Most significant differences were obtained for time of exposure of 1 and 24 hours and maximum reductions was 12%. Furthermore, seedlings from magnetically treated seeds grew taller than control. The longest mean total length was obtained from seedlings exposed to 125 and 250 mT for 24 hours. External magnetic fields are assumed to enhance seed vigor by influencing the biochemical processes by stimulating activity of proteins and enzymes. Numerous studies suggested that magnetic field increases ions uptake and consequently improves nutrition value.

Determination of the Probability Distribution of the Mean Sound Level

2010 ◽  
Vol 35 (4) ◽  
pp. 543-550 ◽  
Author(s):  
Wojciech Batko ◽  
Bartosz Przysucha
Keyword(s):  
Probability Distribution ◽  
Probability Distribution Function ◽  
Mean Value ◽  
Sound Level ◽  
Function Form ◽  
Noise Levels ◽  
Logarithmic Mean ◽  
The Mean ◽  
Estimation Of Uncertainty

AbstractAssessment of several noise indicators are determined by the logarithmic mean <img src="/fulltext-image.asp?format=htmlnonpaginated&src=P42524002G141TV8_html\05_paper.gif" alt=""/>, from the sum of independent random resultsL1;L2; : : : ;Lnof the sound level, being under testing. The estimation of uncertainty of such averaging requires knowledge of probability distribution of the function form of their calculations. The developed solution, leading to the recurrent determination of the probability distribution function for the estimation of the mean value of noise levels and its variance, is shown in this paper.

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