scholarly journals Effect of Charpy Striker Configuration on Low- and High-Energy NIST Verification Specimens

2018 ◽  
Vol 123 ◽  
Author(s):  
Enrico Lucon ◽  
Jolene Splett
Keyword(s):  
Test Data ◽  
Energy Levels ◽  
High Energy ◽  
Low Energy ◽  
Absorbed Energy ◽  
The Past ◽  
Edge Radius ◽  
Charpy Absorbed Energy ◽  
Certified Values

Charpy machines can be equipped with strikers having two different configurations, corresponding to an edge radius of 2 mm or 8 mm. Both striker types are covered by ASTM E23 and ISO 148-1. The effect of striker type on Charpy absorbed energy has been extensively investigated in the past, and clear evidence has been published showing that when using 8 mm strikers, absorbed energy (KV) tends to increase for specimens with KV ≥ 200 J. In this paper, we investigate how striking edge radius affects certified values and uncertainties for National Institute of Standards and Technology (NIST) low-energy and high-energy verification specimens. Test data from two low-energy and two high-energy Charpy lots, analyzed in a statistically rigorous manner, were somewhat contradictory and led to the decision to separately certify low-energy and high-energy lots for use with 2 mm and 8 mm strikers. This agrees with previous findings by other NIST researchers, who recommended individual certifications for the two strikers at all energy levels.

Theoretical photoionization study of Ti9+ ion

2020 ◽  
Author(s):  
Hongbin Wang ◽  
Gang Jiang
Keyword(s):  
Cross Sections ◽  
Energy Levels ◽  
Radiative Transition ◽  
High Energy ◽  
Low Energy ◽  
Transition Rates ◽  
Channel Coupling ◽  
R Matrix ◽  
Good Consistency ◽  
Good Agreement

Photoionization (PI) of Ti<sup>9+</sup> ion is investigated by the Dirac R-matrix method. Multi-Configuration Dirac-Fock (MCDF) calculations are performed to construct accurate target functions. Good agreement of energy levels and radiative transition rates indicate the accuracy of target functions. PI cross sections show good consistency between length and velocity forms. The results are consistent with the previous theoretical values in high-energy regions. Partial waves contribution to the total PI cross sections are discussed for the ground and metastable states. Moreover, the PI cross sections are dominated by many resonance structures and affected by the channel coupling effects in low-energy region. In addition to providing data for the Opacity Project TOPbase, the present work promotes plasma simulation and diagnosis.

scholarly journals Ruminal Microbiota and Fermentation in Response to Dietary Protein and Energy Levels in Weaned Lambs

Animals ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 109 ◽  
Author(s):  
Xiaokang Lv ◽  
Kai Cui ◽  
Minli Qi ◽  
Shiqin Wang ◽  
Qiyu Diao ◽  
...  
Keyword(s):  
Growth Performance ◽  
Energy Levels ◽  
High Energy ◽  
Metabolizable Energy ◽  
Low Energy ◽  
Dietary Energy ◽  
Ruminal Fermentation ◽  
Protein Levels ◽  
Energy Group ◽  
Low Energy Diet

Supplying sufficient nutrients, such as dietary energy and protein, has a great effect on the growth and rumen development of ruminants. This study was conducted to evaluate the effects of dietary energy and protein levels on growth performance, microbial diversity, and structural and physiological properties of the rumen in weaned lambs. A total of 64 two-month-old Hu lambs were randomly allotted to 2 × 2 factorial arrangements with four replicates and with four lambs (half male and half female) in each replicate. The first factor was two levels of dietary metabolizable energy (ME) density (ME = 10.9 MJ/Kg or 8.6 MJ/Kg), and the second factor was two levels of dietary crude protein (CP) content (CP = 15.7% or 11.8%). The trial lasted for 60 days. A low dietary energy level restrained the growth performance of lambs (p < 0.05). The ruminal concentration of acetate and the ratio of acetate to propionate increased but the propionate concentration decreased significantly with the low energy diet. However, the rumen morphology was not affected by the diet energy and protein levels. Moreover, a low energy diet increased ruminal bacterial diversity but reduced the abundance of the phylum Proteobacteria (p < 0.05) and genus Succinivibrionaceae_uncultured (p < 0.05), which was associated with the change in ruminal fermentation phenotypes. By indicator species analysis, we found three indicator OTUs in the high energy group (Succinivibrionaceae_uncultured, Veillonellaceae_unclassified and Veillonellaceae_uncultured (p < 0.01)) and two indicator OTUs in the low energy group (Bacteroidales_norank and Lachnospiraceae_uncultured (p < 0.01)). In conclusion, these findings added new dimensions to our understanding of the diet effect on rumen microbial community and fermentation response, and are of great significance for establishing the optimal nutrient supply strategy for lambs.

Next Generation Ductile Fracture Arrest Analyses for High Energy Pipelines Based on Detail Coupling of CFD and FEA Approach

2018 ◽  
Author(s):  
K. K. Botros ◽  
E. J. Clavelle ◽  
M. Uddin ◽  
G. Wilkowski ◽  
C. Guan
Keyword(s):  
Ductile Fracture ◽  
Test Data ◽  
Fracture Propagation ◽  
Crack Tip ◽  
Propagation Speed ◽  
High Energy ◽  
Computational Effort ◽  
Pipe Material ◽  
The Past ◽  
Toughness Parameter

Axial ductile fracture propagation and arrest in high energy pipelines has been studied since the early 1970’s with the development of the empirical Battelle Two-Curve (BTC) model. Numerous empirical corrections on the backfill, gas decompression models, and fracture toughness have been proposed over the past decades. While this approach has worked in most cases, the dynamic interaction between the decompression of the fluid in the vicinity of the crack tip and the behaviour of the pipe material as it opens to form flaps behind the crack has been very difficult to solve from a more fundamental approach. The effects of the pressure distribution on the flap inner surface making up the crack-driving force which drives the crack propagation speed has been suggested in the past, but due to intensive computational effort required, it was never realized. The present paper attempts to tackle this problem by employing an iterative solution procedure where the gas pressure field in the vicinity of the crack tip is accurately solved for by computational fluid dynamics (CFD) for a given flap geometry determined from a dynamic FEA model to render a new flap geometry. In this model a cohesive-zone element at the crack tip is employed as a representation of the material toughness parameter. The final outcome is the determination of the cohesive energy in the FEA (as a representation of the material toughness parameter) to match the measured fracture propagation speed for the specific case. A case study was taken from full-scale rupture test data from one of the pipe joints from the Japanese Gas Association (JGA) unbackfilled pipe burst test data conducted in 2004 on the 762 mm O.D., 17.5 mm wall thickness, Gr. 555 MPa (API 5L X80) pipe.

Crude protein requirements of large frame cattle fed two levels of energy as weaned calves or as backgrounded yearlings

1993 ◽  
Vol 73 (2) ◽  
pp. 315-325 ◽  
Author(s):  
J. J. McKinnon ◽  
R. D. H. Cohen ◽  
D. A. Christensen ◽  
S. D. M. Jones
Keyword(s):  
Energy Balance ◽  
Key Words ◽  
Crude Protein ◽  
Energy Levels ◽  
Average Daily Gain ◽  
High Energy ◽  
Carcass Composition ◽  
Low Energy ◽  
Protein Requirements ◽  
Daily Gain

Two trials were conducted to determine the crude protein (CP) requirements of large-frame (LF) cattle managed under two regimes and fed one of two energy levels. Trial 1 involved 216 recently weaned LF calves, while trial 2 involved 192 LF backgrounded yearling steers. In each trial, the cattle were fed diets formulated to one of two energy levels (11.17 and 11.88 MJ ME kg−1 DM) and one of six CP levels (11, 13, 15, 16, 17 and 19% DM basis). High-energy feeding increased (P < 0.05), average daily gain (ADG), average daily carcass gain (ADCG) and average daily fat gain (ADFG) of weaned calves but did not influence the performance of the backgrounded yearlings. Weaned calves fed 16, 17 or 19% CP had higher (P < 0.05) ADG than those fed 11%, while those fed 16% CP exhibited increased (P < 0.05) ADFG. ADG and ADCG of weaned calves and backgrounded yearlings and ADFG of weaned calves fed low-energy diets increased (P < 0.05) linearly with increasing dietary CP concentration. Daily carcass lean gain of weaned calves fed low-energy diets decreased in a quadratic manner (P < 0.05) as dietary CP level increased. No influence of dietary CP concentration was observed on carcass tissue gain of the backgrounded yearlings. It was concluded that energy balance of animals fed low-energy diets improved with CP supplementation and that current NAS-NRC (1984) CP requirements accurately predict performance of LF cattle. Key words: Steers, growth, carcass composition, energy, crude protein

Overview of NIST Activities on Sub-Size and Miniaturized Charpy Specimens: Correlations With Full-Size Specimens and Verification Specimens for Small-Scale Pendulum Machines

2015 ◽  
Author(s):  
Enrico Lucon ◽  
Chris N. McCowan ◽  
Raymond L. Santoyo
Keyword(s):  
Impact Test ◽  
Energy Levels ◽  
High Energy ◽  
Maximum Force ◽  
Small Scale ◽  
Test Results ◽  
Absorbed Energy ◽  
Line Pipe ◽  
Full Size ◽  
Alloy Steels

NIST in Boulder Colorado investigated the correlations between impact test results obtained from standard, full-size Charpy specimens (CVN) and specimens with reduced thickness (sub-size Charpy specimens, SCVN) or reduced or scaled cross-section dimensions (miniaturized Charpy specimens, MCVN). A database of instrumented impact test results was generated from four line pipe steels, two quenched and tempered alloy steels, and an 18 Ni maraging steel. Correlations between specimen types were established and compared with previously published relationships, considering absorbed energy, ductile-to-brittle transition temperature, and upper shelf energy. Acceptable correlations were found for the different parameters, even though the uncertainty of predictions appears exacerbated by the expected significant experimental scatter. Furthermore, we report on the development of MCVN specimens for the indirect verification of small-scale pendulum machines (with potential energies between 15 J and 50 J), which cannot be verified with full-size verification specimens. Small-scale pendulum machines can now be verified at room temperature with certified reference specimens of KLST type (3 mm × 4 mm × 27 mm), supplied by NIST at three certified absorbed energy levels (low energy, 1.59 J; high-energy, 5.64 J; super-high energy, 10.05 J). These specimens can also be used to verify the performance of instrumented Charpy strikers through certified maximum force values. Certified reference values for both absorbed energy and maximum force were established by means of an interlaboratory comparison (Round-Robin), which involved nine qualified and experienced international laboratories.

Microstructure of NiCrBSi Laser Cladding Coatings Textured by Nd-YAG Laser

2011 ◽  
Author(s):  
A. Higuera-Garrido ◽  
R. Gonza´lez ◽  
M. Cadenas ◽  
J. L. Viesca ◽  
A. Herna´ndez-Battez
Keyword(s):  
Surface Treatment ◽  
Internal Combustion Engines ◽  
Tribological Behavior ◽  
Energy Levels ◽  
Full Range ◽  
High Energy ◽  
Low Energy ◽  
Manufacturing Processes ◽  
Combustion Engines ◽  
Scientific Fields

The use of texturing as a surface treatment that improves the tribological behavior is widespread in industrial and scientific fields, it is used in internal combustion engines [1], in biomechanical applications [2], in manufacturing processes [3] and in a full range of different applications. When texturing is carried out at low energy levels, the material melts superficially in a process governed by convection and thermocapillarity phenomena [4], whereas at high energy levels the reaction of the material could lead to its sudden vaporization [5] and local melting.

FACTORS AFFECTING THE PERSISTENCE OF STRANDED OIL ON LOW ENERGY COASTS

1985 ◽  
Vol 1985 (1) ◽  
pp. 359-365 ◽  
Author(s):  
Edward H. Owens
Keyword(s):  
Residence Time ◽  
Wave Energy ◽  
Energy Levels ◽  
Open Water ◽  
High Energy ◽  
Low Energy ◽  
Factors Affecting ◽  
Shoreline Changes ◽  
The North ◽  
Mechanical Dispersion

ABSTRACT Mechanical dispersion by waves is usually considered to be the primary factor that controls the persistence of spilled oil reaching the coast. This assumption is accurate for stable coasts that are not subject to net erosion or accretion and beaches where oil would not be buried by onshore, offshore, or alongshore movement of sediments. On high energy coasts, oil can be rapidly buried or eroded, depending on the stage of beach changes. Similarly, oil stranded on coasts subject to rapid net accretion or erosion is likely to be buried or dispersed. Rapid shoreline changes can occur in areas of low wave energy, so wave energy levels cannot be used alone as an indicator of oil persistence. Sections of the North American Beaufort Sea coast are undergoing net long term changes on the order of 10 meters per year, despite the short (3 month) open water season and the small fetch areas. Beach migration or cliff retreat on these low energy coasts often has a net rate on the order of one meter per month. In these situations, the changes in shoreline location due to sediment erosion and transport reflect the integrated effect of coastal processes and the materials on which the processes act. Rates of shoreline changes can be used as an indicator to estimate the residence time of stranded oil, irrespective of the shoreline character or the wave energy levels at the shoreline. Wave energy levels alone are an inadequate basis for estimating the residence time of stranded oil.

scholarly journals Hepatic Injury Induced by Dietary Energy Level via Lipid Accumulation and Changed Metabolites in Growing Semi-Fine Wool Sheep

2021 ◽  
Vol 8 ◽  
Author(s):  
Benchu Xue ◽  
Qionghua Hong ◽  
Xiang Li ◽  
Mingli Lu ◽  
Jia Zhou ◽  
...  
Keyword(s):  
Energy Level ◽  
Lipid Accumulation ◽  
Hepatic Injury ◽  
Energy Levels ◽  
High Energy ◽  
Protein Carbonyl ◽  
Low Energy ◽  
Metabolic Energy ◽  
Dietary Energy ◽  
Tnf Α

Liver injury threatens the overall health of an organism, as it is the core organ of the animal body. Liver metabolism is affected by numerous factors, with dietary energy level being a crucial one. Therefore, the present study aimed to evaluate hepatic injury and to describe its metabolic mechanism in ruminants fed diets with different dietary energy levels. A total of 25 Yunnan semi-fine wool sheep were fed diets with five dietary metabolic energy levels and were randomly assigned to five groups as follows: low energy (LE), medium–low energy (MLE), medium energy (ME), medium–high energy (MHE), and high energy (HE). The results revealed that the average optical density (AOD) of lipid droplets in the LE, MLE, and HE groups was higher than that in the ME and MHE groups. The enzyme activity of alanine aminotransferase (ALT) was the lowest in the ME group. An increase in dietary energy level promoted the superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activity and altered the malondialdehyde (MDA) and protein carbonyl (PCO) concentration quadratically. In addition, both high and low dietary energy levels upregulated the mRNA abundance of proinflammatory cytokine interleukin (IL)-1β, nuclear factor-kappa B (NF-κB), and tumor necrosis factor (TNF)-α. Metabonomic analysis revealed that 142, 77, 65, and 108 differential metabolites were detected in the LE, MLE, MHE, and HE groups, compared with ME group respectively. These metabolites were involved in various biochemical pathways, such as glycolipid, bile acid, and lipid metabolism. In conclusion, both high and low dietary energy levels caused hepatic injury. Section staining and metabonomic results revealed that hepatic injury might be caused by altered metabolism and lipid accumulation induced by lipid mobilization.

Effects on seal properties of changes in drops energy and water salinity during a continuous rainstorm

Soil Research ◽  
1988 ◽  
Vol 26 (4) ◽  
pp. 651 ◽  
Author(s):  
M Agassi ◽  
I Shainberg ◽  
J Morin
Keyword(s):  
Kinetic Energy ◽  
Electrolyte Concentration ◽  
Saline Water ◽  
Energy Levels ◽  
High Energy ◽  
Low Energy ◽  
Water Salinity ◽  
Distilled Water ◽  
Sodium Percent ◽  
Silty Loam

The effect of changes in rainfall energy and water salinity, during a continuous simulated rainstorm, on seal properties was tested in a silty loam soil (Calcic Haploxeralfl with medium (9.0) and low (2.5) exchangeable sodium percent (ESP) values. Saline water (EC = 5 -6 dS m-1) and distilled water were rained at two energy levels: high energy with kinetic energy of 22.9 J mm-1 m2, and low energy with kinetic energy of <0.01 J mm-1 m-2. A seal may be fully or partially developed. The seal formed by a distilled water rain of high energy and sufficient duration is fully developed. A seal formed by rain with low energy, or by high-energy rain of short duration, or by saline rainwater of high energy and long duration, is a partially developed seal. A fully developed seal is stable and its permeability responds only to simultaneous changes in electrolyte concentration and rain energy. Conversely, a partially developed seal is not stable and its permeability responds to changes in electrolyte concentration only.

Low energy vs. high energy depositional settings and related sedimentary bodies in early Senenian rudist bearing carbonate shelves (central-southern Italy)

2001 ◽  
Vol 28 (1) ◽  
pp. 37-40 ◽  
Author(s):  
Gabriele Carannante ◽  
A. Laviano ◽  
D. Ruberti ◽  
Lucia Simone ◽  
G. Sirna ◽  
...  
Keyword(s):  
Southern Italy ◽  
High Energy ◽  
Low Energy ◽  
Depositional Settings
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