10-Year Experience With T23(2.25Cr-1.6W) and T122(12Cr-0.4Mo-2W) in a Power Boiler

2004 ◽  
Author(s):  
N. Komai ◽  
F. Masuyama ◽  
S. Yamamoto ◽  
M. Igarashi
Keyword(s):  
Growth Rate ◽  
Pressure Vessels ◽  
Steam Oxidation ◽  
Remarkable Change ◽  
Field Exposure ◽  
Exposure Test ◽  
One Year ◽  
Power Boiler ◽  
Oxidation Behaviors ◽  
Oxidation Scale

Tungsten strengthened ferritic steels, 2.25Cr-1.6W-V-Nb and 12Cr-0.4Mo-2W-V-Nb-Cu have been developed and approved by the ASME Boiler and Pressure Vessels Code Committee for use in Section I construction, designated as T23 and T122 respectively. A field exposure test installing both steel tubes in service along with comparative materials in the tertiary superheater and secondary reheater of a 156MW utility power boiler has been conducted since April 1993. The tubes were removed to confirm their material properties and corrosion/steam oxidation behaviors after one-year, 3-year, 6-year and 10-year periods of service. The tensile and creep rupture strengths of both steels showed no remarkable change during service. Examination of steam oxidation scale on the inner surface of the tubes indicated that the scale growth rate of T122 was extremely small following one-year service. The growth rate and morphology of steam oxidation scale is discussed, as compared with conventional materials.

10-Year Experience With T23(2.25Cr-1.6W) and T122(12Cr-0.4Mo-2W) in a Power Boiler

2004 ◽  
Vol 127 (2) ◽  
pp. 190-196 ◽  
Author(s):  
N. Komai ◽  
F. Masuyama ◽  
M. Igarashi
Keyword(s):  
Growth Rate ◽  
Pressure Vessels ◽  
Steam Oxidation ◽  
Steel Tubes ◽  
Remarkable Change ◽  
Field Exposure ◽  
Exposure Test ◽  
Power Boiler ◽  
Oxidation Behaviors ◽  
Oxidation Scale

Tungsten strengthened ferritic steels, 2.25Cr-1.6W-V-Nb and 12Cr-0.4Mo-2W-V-Nb-Cu have been developed and approved by the ASME Boiler and Pressure Vessels Code Committee for use in Section I construction, designated as T23 and T122, respectively. A field exposure test installing both steel tubes in service along with comparative materials in the tertiary superheater and secondary reheater of a 156MW utility power boiler has been conducted since April 1993. The tubes were removed to confirm their material properties and corrosion/steam oxidation behaviors after 1-year, 3-year, 6-year, and 10-year periods of service. The tensile and creep rupture strengths of both steels showed no remarkable change during service. Examination of steam oxidation scale on the inner surface of the tubes indicated that the scale growth rate of T122 was extremely small following 1-year service. The growth rate and morphology of steam oxidation scale is discussed, as compared with conventional materials.

scholarly journals ECOLOGICAL STUDIES ON NEPENTHES AT BARITO ULU, CENTRAL KALIMANTAN, INDONESIA

2011 ◽  
Vol 9 (3) ◽  
Author(s):  
Muhammad Mansur
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Stem Length ◽  
Ecological Studies ◽  
Central Kalimantan ◽  
Length Growth ◽  
Small Plot ◽  
Heath Forest ◽  
One Year ◽  
The One

Ecological studies on the Nepenthes species at Barito Ulu, Central Kalimantan, Indonesia were conducted between August 2005 and September 2006. Surveys and two small plot inventories were used to determine the diversity and population of Nepenthes at the study site. We found eight Nepenthes species around the BaritoUlu study area: N. albomarginata, N. ampullaria, N. gracilis, N. hirsuta, N. rafflesiana, N. reinwardtiana, N. stenophylla, and N. hispida. Plot A was dominated by N. rafflesiana with one other species found; whilst in plot B we found five species but it was also dominated by N. rafflesiana. In plot A, the one year stem length growth rate of N. albomarginata was faster than N. rafflesiana (5.0 and 3.5 cm respectively). While in plot B, N. gracilis (21.7 cm) and N. reinwardtiana (13.1 cm) showed faster growth rates than N. albomarginata (5.2 cm), N. rafflesiana (7.0 cm) and N. stenophylla (8.5 cm). Generally, the habitat of Nepenthes in the study site is heath forest.

scholarly journals Ewe reproductive performance and growth rate of suckling-lambs on endophyte-infected perennial ryegrass pasture

1999 ◽  
Vol 7 ◽  
pp. 19-26
Author(s):  
R.H. Watson ◽  
R.G. Keogh ◽  
M.F. Mcdonald
Keyword(s):  
Growth Rate ◽  
Perennial Ryegrass ◽  
Reproductive Performance ◽  
Growth Rates ◽  
Ovulation Rate ◽  
Grazing Management ◽  
One Year ◽  
Lamb Growth

Two groups (n=39) of Romney breeding ewes were maintained under the same grazing management on either endophyte-infected (E+) or endophytefree (E-) perennial ryegrass pasture for two years (1997-1998) following a one-year equilibration period. The ewes were naturally mated in March each year and ovulation rate at 1st mating was measured, and conception and the number of lambs born and weaned were recorded. All ewes were weighed monthly and lamb growth rates were determined between birth and weaning. Mean mating date was delayed by 1.8 days (P

Selection for components of efficient lean growth in Landrace pigs

1994 ◽  
Vol 1994 ◽  
pp. 10-10
Author(s):  
M.K. Curran ◽  
N.D. Cameron
Keyword(s):  
Growth Rate ◽  
Selection Criteria ◽  
Conversion Ratio ◽  
Control Line ◽  
Food Conversion ◽  
Lean Growth ◽  
Food Conversion Ratio ◽  
Daily Food ◽  
Selection For ◽  
One Year

To study responses to divergent selection for lean growth rate (LGA), lean food conversion ratio (LFC) and daily food intake (DFI), an experiment was started in 1984 at Edinburgh and Wye. This paper measured the selection pressure applied, the responses in the selection criteria and estimated the genetic and phenotypic relationships between the selection criteria with ad-libitum feeding of Landrace pigs after four generations of selection.The LGA (LFC) selection objective was to obtain equal correlated responses in growth rate (food conversion ratio) and carcass lean content, measured in phenotypic s.d. The LGA, LFC and DFI selection criteria had phenotypic s.d. of 32, 29 and 270 units and results are presented in s.d. units.Boars and gilts were purchased from eight British nucleus herds and boars from national artificial insemination centres in 1982. Homozygous or heterozygous halothane positive pigs were not included in the experiment. The base population consisted of 20 sires and 89 dams. Within each of the three selection groups, there were high and low selection lines with a control line, each consisting of 10 boars and 20 gilts, with a generation interval of one year. There were two control lines, one for LGA and one for LFC and DFI, as selection groups were arrowed continuously. The total number of pigs tested per line and average inbreeding coefficient at generation 4, within selection group are given below.

Body growth and its implications in population dynamics of Acanthodactylus erythrurus (Schinz, 1834) in the Eastern Iberian peninsula

2019 ◽  
Vol 40 (3) ◽  
pp. 305-312
Author(s):  
Robby Marcel Drechsler ◽  
Juan Salvador Monrós
Keyword(s):  
Growth Rate ◽  
Population Dynamics ◽  
Statistical Significance ◽  
Growth Curves ◽  
High Statistical Significance ◽  
General Data ◽  
One Year ◽  
Best Fit ◽  
Logarithmic Growth

Abstract We calculated growth rate for the spiny-footed lizard (Acanthodactylus erythrurus) inhabiting coastal eastern Spain from long-term mark-recapture data. Growth curves differ between sexes, with males growing faster than females and achieving larger size maximums. In this population each sex reaches maturity at about 300 days of age, approximately 34% faster than males, and 28% faster than females studied in a population further south and west in Iberia. Our logarithmic growth model has an accuracy of 96.8% and high statistical significance ( for males and for females). Although both the exponential curve of “best fit” for growth estimated for males (), and the linear curve of “best fit” estimated for females () in a population from Cádiz (Busack and Jaksic, 1982) are also significant. The overlap between growth curves and the general data cloud of the population showed that at the end of the year the proportion of individuals younger than one year was 80% and the proportion of individuals older than one year was 20%. Our data, in agreement with calculated maximum life spans for males (1.9 years) and females (2.1 years) in Cádiz, suggest a life span of approximately two years for both sexes. Females seem to reproduce only in a unique season in their lives, at this locality, as in Cádiz (Busack and Klosterman, 1987) they likely lay only one clutch, whereas females in Morocco (Bons, 1962) may produce two.

scholarly journals Thermal-Stress Ratchet Mechanism in Pressure Vessels

1959 ◽  
Vol 81 (2) ◽  
pp. 190-194 ◽  
Author(s):  
D. R. Miller
Keyword(s):  
Growth Rate ◽  
Thermal Stress ◽  
Internal Pressure ◽  
Strain Hardening ◽  
Thermal Stresses ◽  
Pressure Vessels ◽  
Progressive Reduction ◽  
Ratchet Mechanism

The combination of cyclic thermal stresses and sustained internal pressure in a vessel is shown to be a source of progressive expansion of the vessel if the stresses are sufficiently high. Criteria presented allow determination of limits to be imposed on stresses in order to prevent progressive expansion or to allow estimation of the expansion per cycle where stresses are sufficient to produce growth. The effect of strain-hardening of the metal on progressive reduction of the growth rate is discussed.

LOCAL CORROSION ENVIRONMENT AROUND CROSS SECTION OF A PLATE GIRDER BRIDGE

2017 ◽  
Vol 4 (1) ◽  
Author(s):  
Kazuto Maruyama ◽  
Seiya Kamasaki ◽  
Keiji Tajima ◽  
Toshihiko Aso
Keyword(s):  
Bottom Flange ◽  
Steel Bridge ◽  
Corrosive Environment ◽  
Water Leakage ◽  
Exposure Test ◽  
The Difference ◽  
Girder Bridge ◽  
One Year ◽  
A Site ◽  
Plate Girder

Corrosion is one of important factor for securing the safety of steel bridges. In general cases, the corrosive environment of the steel bridge is evaluated as a site environment. However, even in one bridge, the corrosive environment greatly varies from part to part. This research aims to clarify the difference of corrosion environment for each part of plate-girder-bridge which has three main girders. At this bridge, anti-freezing agent is sprayed in winter. On site measurements were performed on five points on each girder, which are both sides of web, both sides of upper/lower part of bottom flange. These measurements points include two points where water leakage is scattered. Temperature, humidity, amount of airborne salt and amount of adhering salt have been measured. In order to comprehensively assess corrosive condition, exposure test was also performed. Observations were carried out for one year. From measurement results, it became clear that temperature and humidity were not uniform at all observation points. These were differed at the inside and outside of girder and upper part and lower part of web. Amount of airborne salt to each girder is strongly influenced by anti-freezing agent. On the upper surface of the lower flange of each girder, there are places where corrosion markedly progresses due to deposits and water leakage.

ENZYME HETEROZYGOSITY ASSOCIATED WITH GROWTH AT DIFFERENT DEVELOPMENTAL STAGES IN OYSTERS

1982 ◽  
Vol 24 (4) ◽  
pp. 451-458 ◽  
Author(s):  
Shiva M. Singh
Keyword(s):  
Growth Rate ◽  
Prince Edward Island ◽  
Developmental Stages ◽  
Age Groups ◽  
Age Group ◽  
Cape Breton ◽  
Random Samples ◽  
Specific Mortality ◽  
One Year ◽  
Polymorphic Enzymes

Following our earlier reports on one-year-old oyster populations of Prince Edward Island (Singh and Zouros, 1978, 1981; Zouros et al., 1980), cohorts of three-year classes were studied from Cape Breton, Nova Scotia. Random samples of about 200 individuals from each year class were analyzed for four polymorphic enzymes. A number of generalizations emerged. There was a general deficiency of heterozygotes in the three age groups and this deficiency decreased with age (reflecting reduction in heterozygote deficiency). This suggests genotype-specific mortality during ontogeny. The deficiency of heterozygotes was more pronounced in slower growing, lighter individuals than in faster growing, heavier individuals. The number of heterozygous loci per individual was positively correlated with mean growth rate. The variance in weight was lower in heterozygotes; it decreased with increase in number of heterozygous loci in a given age group. Overdominance in growth rate appears to be the most plausible explanation for these observations.

scholarly journals Nitric acid and particulate matter measurements at Athens, Greece, in connection with corrosion studies

2009 ◽  
Vol 9 (21) ◽  
pp. 8309-8316 ◽  
Author(s):  
C. Tzanis ◽  
C. Varotsos ◽  
M. Ferm ◽  
J. Christodoulakis ◽  
M. N. Assimakopoulos ◽  
...  
Keyword(s):  
Test Site ◽  
Water Soluble ◽  
Passive Samplers ◽  
Field Exposure ◽  
Exposure Test ◽  
Corrosion Studies ◽  
Long Time ◽  
The University ◽  
The Vertical Distribution ◽  
The Eu

Abstract. For a long time, scientists have been concerned about the effects of air pollution on materials and especially on the monuments of the cultural heritage. The EU funded a project, entitled MULTI-ASSESS, to determine these effects and to develop dose-response functions appropriate for the new multi-pollutant environment. The University of Athens participated in this effort as a targeted field exposure test site. In the present paper, the measurements of the passive samplers, which were exposed during the same period with the samples for corrosion studies, at the Athens station, are presented. The results have shown that only 16.5% of the deposited mass was water soluble. The vertical distribution of passive particle collectors has led to the conclusion that the height of maximum deposition of each ion is different. In addition, a variation of the water-soluble mass to total deposited mass between 8% and 31% was observed.

scholarly journals Volatility behavior of virtual currencies

2019 ◽  
Vol 10 (2) ◽  
pp. 537
Author(s):  
Jéssica Gonçalves Andrade ◽  
Nilson Brandalise
Keyword(s):  
Growth Rate ◽  
Data Analysis ◽  
Average Rate ◽  
Rate Of Return ◽  
Average Risk ◽  
Average Growth Rate ◽  
Average Growth ◽  
Volatility Analysis ◽  
One Year ◽  
Made In

In order to do a volatility analysis, since the exchange rate is higher than the average risk, the higher the average rate of return, the higher the average growth rate of the year. applied the method of data analysis. An attempt to volatility analysis can be made in one year, in the middle of the end of 2016.

Sign in / Sign up

Export Citation Format

Share Document