Approach to Assessment of Corrosion Growth in Pipelines

2002 ◽  
Author(s):  
Bill Gu ◽  
Richard Kania ◽  
Sandeep Sharma ◽  
Ming Gao
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Assessment Tool ◽  
Accurate Determination ◽  
Soil Drainage ◽  
Corrosion Condition ◽  
Preliminary Corrosion ◽  
Corrosion Defects ◽  
Growth Assessment

Two key components of corrosion growth assessment in pipelines are accurate determination of corrosion growth rate and application of corrosion growth to future integrity of a pipeline. PII has developed a corrosion growth assessment tool, Run Comparison (RunCom) software that allows accurate determination of corrosion growth. RunCom compares the raw signals of the same defect present in two inspection runs to report the real active corrosion defects and their growth with less error. Since variations in corrosion growth along the pipeline can be significant, a single value of average or maximum corrosion growth rate does not represent the corrosion condition of the pipeline and could result in a conservative or non-conservative conclusion for future integrity. PII introduces a Decision Tree Analysis method to categorize the corroded regions along the pipeline and calculate the mean corrosion growth rates in these specific areas. Relationships between corrosion growth rate and defect geometry are also identified. The influence of soil, drainage, and topography on corrosion rates is examined to determine representative corrosion growth rates along the pipeline. A systematic approach incorporating statistical analysis with mechanistic understanding of corrosion for preliminary corrosion assessment of pipeline systems is discussed.

Radiocarbon dating of Chinese Ancient Tea Trees

Radiocarbon ◽  
2019 ◽  
Vol 61 (6) ◽  
pp. 1741-1748
Author(s):  
Jia Chen ◽  
Hongtao Shen ◽  
Kimikazu Sasa ◽  
Haihui Lan ◽  
Tetsuya Matsunaka ◽  
...  
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Radial Growth ◽  
Accurate Determination ◽  
Annual Rings ◽  
The World ◽  
Automated Sample Preparation ◽  
The University

ABSTRACTThe jungles of Linyun and Longlin Autonomous Prefecture, located in the heart of the southwestern Guangxi Zhuang Autonomous Region of China, are home to the oldest tea trees (Camellia sinensis) in the world. In the absence of regular annual rings, radiocarbon (14C) dating is one of the most powerful tools that can assist in the determination of the ages and growth rates of these plants. In this work, cores were extracted from large ancient tea trees in a central Longlin rain forest; extraction of carbon was performed with an automated sample preparation system. The 14C levels in the tree cores were measured using accelerator mass spectrometry (AMS) at the University of Tsukuba. These measurements indicated that contrary to conventional views, the ages of trees in these forests range up to ~700 years, and the growth rate of this species is notably slow, exhibiting a long-term radial growth rate of 0.039±0.006 cm/yr. It was demonstrated that 14C analyses provide accurate determination of ages and growth rates for subtropical wild tea trees.

scholarly journals Prenatal and postnatal growth: An ultrasound and clinical investigation

2016 ◽  
Vol 6 ◽  
pp. 147-153
Author(s):  
Shahista Parveen ◽  
Rohan Mascarenhas ◽  
Akhter Husain ◽  
Devadas Acharya
Keyword(s):  
Growth Rate ◽  
Assessment Tool ◽  
Clinical Investigation ◽  
Normal Pregnancy ◽  
Postnatal Growth ◽  
Fetal Life ◽  
Prenatal Growth ◽  
Facial Development ◽  
The Relationship ◽  
Growth Assessment

Background Understanding facial development requires sound knowledge of growth at different stages. Although studies in the past have established the relationship between prenatal and postnatal growth, little research has been done using noninvasive ultrasound. The purpose of this study is to evaluate correlation between prenatal and postnatal growths using ultrasound as a fetal growth assessment tool. Study Settings: It is a hospital-based study where prenatal growth is measured at different intervals of gestational period and compared with the growth at birth. Materials and Methods: Ten subjects with normal pregnancy were studied using ultrasound. Cephalocaudal growth gradient, body proportions of the fetus were assessed and compared at different stages. Growth was also evaluated at birth and compared with the predicted growth. Results The growth rate of estimated fetal weight is at maximum between the 28th and 32nd week of the fetal life (P ≤ 0.001). The growth rate of head circumference, occipitofrontal diameter, and femur length is maximum between the 20th and 28th week of the fetal life (P < 0.001). Cephalocaudal growth gradient decreases with increased age of the fetus. Conclusions Prenatal growth is correlated with postnatal growth. Ultrasound can be used as a tool for the measurement and prediction of prenatal and postnatal growths.

scholarly journals Determination of In Situ Bacterial Growth Rates in Aquifers and Aquifer Sediments

2003 ◽  
Vol 69 (7) ◽  
pp. 3798-3808 ◽  
Author(s):  
Brian J. Mailloux ◽  
Mark E. Fuller
Keyword(s):  
Growth Rate ◽  
Fluorescence Intensity ◽  
Growth Rates ◽  
Direct Determination ◽  
Shallow Aquifer ◽  
Cell Counting ◽  
Field Scale ◽  
Doubling Times

ABSTRACT Laboratory and field-scale studies with stained cells were performed to monitor cell growth in groundwater systems. During cell division, the fluorescence intensity of the protein stain 5-(and 6-)-carboxyfluorescein diacetate succinimidyl ester (CFDA/SE) for each cell is halved, and the intensity can be tracked with a flow cytometer. Two strains of bacteria, Comamonas sp. strain DA001 and Acidovorax sp. strain OY-107, both isolated from a shallow aquifer, were utilized in this study. The change in the average generation or the average fluorescence intensity of the CFDA/SE-stained cells could be used to obtain estimates of doubling times. In microcosm experiments, the CFDA/SE-based doubling times were similar to the values calculated by total cell counting and were independent of cell concentration. Intact and repacked sediment core experiments with the same bacteria indicated that changes in groundwater chemistry were just as important as growth rates in determining planktonic cell concentrations. The growth rates within the sediment cores were similar to those calculated in microcosm experiments, and preferential transport of the daughter cells was not observed. The experiments indicated that the growth rates could be determined in systems with cell losses due to other phenomena, such as attachment to sediment or predation. Application of this growth rate estimation method to data from a field-scale bacterial transport experiment indicated that the doubling time was approximately 15 days, which is the first known direct determination of an in situ growth rate for bacteria in an aquifer.

scholarly journals Determination of the in situ growth rate of Microcystis based on carbon and nitrogen stable isotope fractionation

2017 ◽  
Vol 18 (3) ◽  
pp. 984-993 ◽  
Author(s):  
Shucong Zhen ◽  
Wei Zhu
Keyword(s):  
Growth Rate ◽  
Stable Isotope ◽  
Growth Rates ◽  
Isotope Fractionation ◽  
Taihu Lake ◽  
Nitrogen Stable Isotope ◽  
Average Growth ◽  
Carbon And Nitrogen ◽  
Stable Isotope Fractionation

Abstract Stable isotope fractionation of carbon and nitrogen in algal cells can be affected by photosynthesis, temperature, nutrient and CO2 concentrations, and cell size. As a consequence, carbon and nitrogen stable isotope techniques are not popular for determining algal growth rates. To counter these issues, this study used BG11 medium to cultivate Microcystis in the laboratory. First, the carbon and nitrogen stable isotope values of the culture medium and the algae are determined. Then, based on changes in isotope fractionation before and after cell division, a function μ = 1.32(1 + x)−0.52 relating growth rate and stable isotope fractionation is established. By substituting stable isotope values from Taihu Lake water and Microcystis into this function, the growth rate of the Microcystis in Taihu Lake is calculated to be 0.64 d−1 in May and 0.12 d−1 in September, with an average growth rate of 0.42 d−1. By incorporating most of the above-mentioned factors influencing isotope fractionation, this method can determine the growth rate of algae based directly on the stable isotope fractionation relationship, enabling simple and practical determination of algae growth rates.

scholarly journals Variation in fat, lactose and protein in human milk over 24h and throughout the first year of lactation

2002 ◽  
Vol 88 (1) ◽  
pp. 29-37 ◽  
Author(s):  
Leon R. Mitoulas ◽  
Jacqueline C. Kent ◽  
David B. Cox ◽  
Robyn A. Owens ◽  
Jillian L. Sherriff ◽  
...  
Keyword(s):  
Growth Rate ◽  
Human Milk ◽  
Energy Content ◽  
Accurate Determination ◽  
Milk Composition ◽  
First Year ◽  
Left And Right ◽  
Daily Milk Production ◽  
Daily Milk

Fat in human milk is extremely variable and can represent up to 50 % of infant energy intake. To accurately determine milk composition and infant intake at 1 (n 17), 2 (n 17), 4 (n 17), 6 (n 15), 9 (n 6) and 12 (n 5) months of lactation, samples of fore- and hind-milk were collected from each breast at each feed over 24 h periods from an initial group of seventeen women. The content of fat in milk varied over 24 h, with a mean CV of 47·6 (SE 2·1) % (N 76) AND 46·7 (se 1·7) % (n 76) for left and right breasts respectively. The 24 h amounts of fat, lactose and protein in milk differed between women (P=0·0001), but were consistent between left and right breasts. Daily milk production differed between breasts (P=0·0001) and women (P=0·0001). Accordingly, amounts of fat (P=0·0008), lactose (P=0·0385) and protein (P=0·0173) delivered to the infant over 24 h also differed between breasts and women (P=0·0001). The energy content of milk and the amount of energy delivered to the infant over 24 h were the same between breasts, but differed between women (P=0·0001). The growth rate of a group of only six infants in the present study was not related to either the concentrations or amounts of fat, lactose, protein and energy in milk over the first 6 months of life. These results show the individuality of milk composition and suggest that only a rigorous sampling routine that takes into account all levels of variation will allow the accurate determination of infant intake of fat, lactose, protein and energy.

Transition from Grey to White and White to Grey in Fe-C-X Eutectic Alloys

1984 ◽  
Vol 34 ◽  
Author(s):  
P. Magnin ◽  
W. Kurz
Keyword(s):  
Growth Rate ◽  
Directional Solidification ◽  
Growth Rates ◽  
Opposite Effect ◽  
Eutectic Temperature ◽  
Alloying Elements ◽  
Qualitative Model ◽  
Eutectic Alloys ◽  
Temperature Growth

ABSTRACTThe effect of small additions of Si, P, Cr, Mn and Ti on transition velocities from grey to white and white to grey of pure Fe-C eutectics has been measured by varying growth rates in directional solidification experiments. Growth undercoolings were measured as a function of growth rate, while white and grey eutectic temperatures were obtained from DTA experiments. As a result of these experiments, alloying elements can be classified into three categories : graphitizing (Si, P), carburizing (Cr) and “opposite effect” (Mn, Ti). Each category is characterized by a given influence on eutectic temperature, growth undercooling, and nucleation of cementite. A qualitative model which permits determination of the influence of alloying elements on these latter three parameters is proposed.

scholarly journals Spreadsheet Iteration of Reversionary Leasehold Rental Growth Rate Within The Framework of Explicit DCF Appraisals

2020 ◽  
Vol 8 (1) ◽  
pp. 29-45
Author(s):  
Joseph Obaje Ataguba
Keyword(s):  
Growth Rate ◽  
Scenario Analysis ◽  
Growth Rates ◽  
Income Growth ◽  
Valuation Model ◽  
Analysis Tools ◽  
Tools And Techniques ◽  
Analytical Tools ◽  
Equivalent Yield

Income growth rates are required to justify decisions and strategies for property investments. Although existing studies addressed this phenomenon in freehold investments, a relative question regarding the determination of rental growth rates of leasehold investment properties valued part-way through rent review periods has not been addressed before now. This study examined the spreadsheet-assisted scenario analysis tools and techniques that are required for the determination of rental growth rates of leasehold investment properties valued part-way through rent review periods. A precursor to the scenario analysis was the development of a hybrid leasehold DCF valuation model arising from the equation of the formula for reversionary leasehold equivalent yield valuation to the formula for reversionary leasehold growth explicit DCF valuation model; thereby culminating into the identification of four unknown variables comprising the all risks yield and the implied growth rates of leasehold cash inflows and cash outflows which were subsequently derived using the solver tool of Excel®. From a total of eleven scenarios generated, the 9th successive scenario produced optimal results indicating zero slack between iterated and calculated values for the growth rates of leasehold cash inflows and cash outflows respectively. With recourse to the hybrid leasehold DCF valuation model, the spreadsheet-assisted scenario was found to produce mathematically valid growth rates that justify the valuation of leasehold investment properties part-way through rent review periods. The value of this research is the analytical tools and rigour it avails investors seeking income returns and growth from reversionary leasehold property as an instance of terminable investments.

Unambiguous and Low-Cost Determination of Growth Rates and Ages of Tropical Trees and Palms

Radiocarbon ◽  
2014 ◽  
Vol 56 (1) ◽  
pp. 39-52 ◽  
Author(s):  
Jorge I del Valle ◽  
Juan R Guarín ◽  
Carlos A Sierra
Keyword(s):  
Growth Rates ◽  
Sustainable Forest Management ◽  
Low Cost ◽  
Accurate Determination ◽  
Tropical Trees ◽  
Forest Inventories ◽  
Management Plans ◽  
Cost Determination

The determination of the age of tropical trees and palms is of significant importance for ecological studies and designing sustainable forest management plans. Radiocarbon is a powerful tool that can potentially help the determination of ages and growth rates of these plants. However, the application of 14C analyses has one important problem for trees without annual rings and palms: the calibration of 14C measurements with common programs such as CALIBomb or OxCal gives erroneous determinations for wood formed between AD 1954 and 1964. This problem is illustrated here using samples from a tropical tree (Otoba gracilipes) and a tropical palm (Oenocarpus bataua). This study shows how the use of two adjacent samples can help to unambiguously determine the real age of the samples and their mean growth rates. For comparison, long-term growth measurements for both species were used and it was determined that 14C analyses provide accurate determination of growth rates for tropical trees and palms. Furthermore, the application of 14C analyses in palms allows the determination of the rosette stage, rarely quantified in forest inventories and life-history studies.

Selection for biomass production based on respiration parameters in eucalypts: acclimation of growth and respiration to changing growth temperature

1996 ◽  
Vol 26 (9) ◽  
pp. 1569-1576 ◽  
Author(s):  
R.S. Criddle ◽  
T.S. Anekonda ◽  
R.M. Sachs ◽  
R.W. Breidenbach ◽  
L.D. Hansen
Keyword(s):  
Growth Rate ◽  
Biomass Production ◽  
Growth Temperature ◽  
Growth Rates ◽  
Heat Rate ◽  
Metabolic Rates ◽  
Different Temperatures ◽  
Controlled Environments ◽  
Respiration Parameters

This paper examines the relation between respiratory physiology and growth rate and the effects of environment on this relation for the purpose of developing means for accelerating and improving selection of trees for biomass production. The relations among biomass production, respiratory metabolism, and growth temperature in controlled environments were determined for three Eucalyptus genotypes (clones). Eucalyptuscamaldulensis 4016, E. camaldulensis C11, and Eucalyptusgundal (Eucalyptusgunnii × Eucalyptusdalrympleana hybrid) GD1 were selected for this study because of known qualitative differences in their field growth responses to temperature. These clones were grown in controlled environments at three temperatures. Measurements were made of growth rate, metabolic heat rate, and dark CO2 production rate for plants grown at each of the three temperatures. This allowed determination of respiration rates of plants originally adapted for growth in different climates, but acclimated during growth at three different controlled temperatures, and also determination of respiration changes resulting from short-term changes in temperature. Growth rates of the three clones differed in their patterns of response to changes in growth temperature. For example, C11 grew most rapidly at the highest temperature, while GD1 was slowest at high temperature. Metabolic rates and the temperature dependence of metabolic rates of the clones differed and the pattern of differences changed when plants became acclimated to growth at different temperatures. Changes in metabolic properties of the three clones with growth and measurement temperatures are consistent with the growth rate changes. In general, increased growth rate was accompanied by increased respiration rate measured either as heat rate or as rate of CO2 production. Growth rates were inversely related to two measures of metabolic energy use efficiency. Growth rates decreased as values of heat loss per gram dry weight produced and values of heat loss per mole of CO2 produced increased. Recognition of these relations between growth rate and respiration parameters at different temperatures in controlled environement may allow prediction of relative growth rate performance of Eucalyptus clones over a range of growth climates.

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