Uniformity Analysis on Temperature Field of Big Diameter GCr15 Bearing Steel Bar in the Process of Immersion Quenching

2014 ◽  
Vol 556-562 ◽  
pp. 86-90
Author(s):  
Guo Yong Liu ◽  
Xue Feng Ma ◽  
Hong Jiang ◽  
Dong Mei Zhu ◽  
Shao Jun Zhang
Keyword(s):  
Numerical Simulation ◽  
Temperature Field ◽  
Bearing Steel ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Gcr15 Bearing Steel ◽  
Steel Bar ◽  
Field Uniformity ◽  
Total Cross Sectional Area

Based on the immersion quenching cooling used at steel bar, numerical simulation about temperature field of big GCr15 bearing steel bar is carried out by the FLUENT. The influence on temperature field uniformity brought by different elements during the immersion quenching cooling is analyzed, such as the number and the diameter of the nozzle when the total cross-sectional area is constant and the distance between the nozzle and the surface of the steel bar. The results show that: a better uniformity of the temperature would be achieved when the number of the nozzle is 11and the diameter of the nozzle is 26mm.when the distance between the nozzle and the surface of the steel bar is 250mm, a better uniformity of the temperature would be gained.

Assessment of sand stabilization potential of a plant-derived biomass

2016 ◽  
Vol 23 (2) ◽  
pp. 227-236 ◽  
Author(s):  
Dunja Perić ◽  
Paul A. Bartley ◽  
Lawrence Davis ◽  
Ali Ulvi Uzer ◽  
Cahit Gürer
Keyword(s):  
Area Ratio ◽  
Cross Sectional Area ◽  
Experimental Program ◽  
Early Age ◽  
Shear Stresses ◽  
Sectional Area ◽  
Cross Sectional ◽  
Near Surface ◽  
Total Cross Sectional Area ◽  
Dry Sand

AbstractLignin is a coproduct of biofuel and paper industries, which exhibits binding qualities when mixed with water. Lignin is an ideal candidate for a sustainable stabilization of unpaved roads. To this end, an experimental program was devised and carried out to quantify effects of lignin on compaction and early age shear strength behaviors of sand. Samples were prepared by mixing a particular type of coproduct called calcium lignosulfonate (CaL) with sand and water. Based on the extensive analyses of six series of strength tests, it was found that a normalized cohesion increased with an increasing normalized areas ratio. Normalizations were carried out by dividing the cohesion and area ratio by gravimetric CaL content whereby the area ratio was obtained by dividing the portion of the cross-sectional area occupied with lignosulfonate-water (CaL-W) paste by the total cross-sectional area. While the increase in the normalized cohesion eventually leveled out, the cohesion peaked at 6% of CaL. Thus, sand-CaL-water (S-CaL-W) mixes sustained larger shear stresses than dry sand for a range of normal stresses below the limiting normal stress. Consequently, the early age behavior indicates that adding CaL-W to sand is clearly beneficial in the near-surface applications in dry sand.

scholarly journals Angiographic Anatomy of Major Aortopulmonary Collateral Arteries and Association With Early Surgical Outcomes in Tetralogy of Fallot

2020 ◽  
Vol 9 (24) ◽  
Author(s):  
Gregory T. Adamson ◽  
Doff B. McElhinney ◽  
Yulin Zhang ◽  
Jeffrey A. Feinstein ◽  
Lynn F. Peng ◽  
...  
Keyword(s):  
Tetralogy Of Fallot ◽  
Surgical Outcomes ◽  
Pulmonary Circulation ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Major Aortopulmonary Collateral Arteries ◽  
Collateral Arteries ◽  
Total Cross Sectional Area ◽  
Aortopulmonary Collateral

Background Due in part to the heterogeneity of the pulmonary circulation in patients with tetralogy of Fallot and major aortopulmonary collateral arteries (MAPCAs), research on this condition has focused on relatively basic anatomic characteristics. We aimed to detail pulmonary artery (PA) and MAPCA anatomy in a large group of infants, assess relationships between anatomy and early surgical outcomes, and consider systems for classifying MAPCAs. Methods and Results All infants ( <1 year of age) undergoing first cardiac surgery for tetralogy of Fallot/MAPCAs from 2001 to 2019 at Stanford University were identified. Preoperative angiograms delineating supply to all 18 pulmonary segments were reviewed for details of each MAPCA and the arborization and size of central PAs. We studied 276 patients with 1068 MAPCAs and the following PA patterns: 152 (55%) incompletely arborizing PAs, 48 (17%) normally arborizing PAs, 45 (16%) absent PAs, and 31 (11%) unilateral MAPCAs. There was extensive anatomic variability, but no difference in early outcomes according to PA arborization or the predominance of PAs or MAPCAs. Patients with low total MAPCA and/or PA cross‐sectional area were less likely to undergo complete repair. Conclusions MAPCA anatomy is highly variable and essentially unique for each patient. Though each pulmonary segment can be supplied by a MAPCA, central PA, or both, all anatomic combinations are similarly conducive to a good repair. Total cross‐sectional area of central PA and MAPCA material is an important driver of outcome. We elucidate a number of novel associations between anatomic features, but the extreme variability of the pulmonary circulation makes a granular tetralogy of Fallot/MAPCA classification system unrealistic.

Genetic Effects on Skeletal Mechanosensitivity in Mice

2002 ◽  
Author(s):  
Charles H. Turner ◽  
Alexander G. Robling
Keyword(s):  
Mechanical Loading ◽  
Cross Sections ◽  
Inbred Mouse ◽  
Cross Sectional Area ◽  
Mouse Strains ◽  
Sectional Area ◽  
Mineral Density ◽  
Bone Apposition ◽  
Cross Sectional ◽  
Total Cross Sectional Area

The accumulation of bone mass during growth can be enhanced by environmental factors such as mechanical loading (exercise) or calcium intake, but 60–70% of the variance in adult bone mineral density (BMD) is explained by heredity. Consequently, understanding the signaling pathways targeted by the genes governing bone accumulation holds perhaps the greatest potential in reducing fracture incidence later in life. Rodent models are particularly useful for studying the genetics of skeletal traits. Of the available inbred mouse strains, three in particular have been studied extensively in skeletal genetics: C57BL/6, DBA/2, and C3H/He. The C57BL/6 strain is characterized by low BMD and large total cross-sectional area (CSA) in the midshaft femur; the C3H/He strain exhibits very high femoral BMD and a smaller femoral CSA than the C57BL/6 mice; and DBA/2 mice have moderately high femoral BMD and a very small midshaft femur CSA. Mechanical loading of the skeleton during growth can substantially enhance periosteal bone apposition, and ultimately produce a diaphyseal cross section with enlarged area. Therefore we hypothesized that the mouse strain with greater femoral cross-sectional area (C57BL/6) might have a genetic predisposition for greater mechanosensitivity than mice with smaller cross sections (C3H/He and DBA/2).

Conservation of bronchiolar wall area during constriction and dilation of human airways

1997 ◽  
Vol 82 (3) ◽  
pp. 954-958 ◽  
Author(s):  
R. W. Mitchell ◽  
E. Rühlmann ◽  
H. Magnussen ◽  
N. M. Muñoz ◽  
A. R. Leff ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Contraction ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Wall Area ◽  
Total Cross Sectional Area ◽  
Human Airways ◽  
Contraction And Relaxation

Mitchell, R. W., E. Rühlmann, H. Magnussen, N. M. Muñoz, A. R. Leff, and K. F. Rabe. Conservation of bronchiolar wall area during constriction and dilation of human airways. J. Appl. Physiol. 82(3): 954–958, 1997.—We assessed the effect of smooth muscle contraction and relaxation on airway lumen subtended by the internal perimeter ( A i) and total cross-sectional area ( A o) of human bronchial explants in the absence of the potential lung tethering forces of alveolar tissue to test the hypothesis that bronchoconstriction results in a comparable change of A iand A o. Luminal area (i.e., A i) and A owere measured by using computerized videomicrometry, and bronchial wall area was calculated accordingly. Images on videotape were captured; areas were outlined, and data were expressed as internal pixel number by using imaging software. Bronchial rings were dissected in 1.0- to 1.5-mm sections from macroscopically unaffected areas of lungs from patients undergoing resection for carcinoma, placed in microplate wells containing buffered saline, and allowed to equilibrate for 1 h. Baseline, A o[5.21 ± 0.354 (SE) mm2], and A i(0.604 ± 0.057 mm2) were measured before contraction of the airway smooth muscle (ASM) with carbachol. Mean A inarrowed by 0.257 ± 0.052 mm2in response to 10 μM carbachol ( P = 0.001 vs. baseline). Similarly, A onarrowed by 0.272 ± 0.110 mm2in response to carbachol ( P = 0.038 vs. baseline; P = 0.849 vs. change in A i). Similar parallel changes in cross-sectional area for A iand A owere observed for relaxation of ASM from inherent tone of other bronchial rings in response to 10 μM isoproterenol. We demonstrate a unique characteristic of human ASM; i.e., both luminal and total cross-sectional area of human airways change similarly on contraction and relaxation in vitro, resulting in a conservation of bronchiolar wall area with bronchoconstriction and dilation.

CORRELATION BETWEEN BODY HABITUS AND CROSS-SECTIONAL AREA OF RIBS

1965 ◽  
Vol 43 (5) ◽  
pp. 773-781 ◽  
Author(s):  
Hideaki Takahashi ◽  
Harold M. Frost
Keyword(s):  
Sampling Site ◽  
Correlation Coefficients ◽  
Correlation Study ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Body Habitus ◽  
Normal People ◽  
Total Cross Sectional Area ◽  
The Relationship

A correlation study was performed of the relationship between the total cross-sectional area of the fifth, sixth, or seventh rib in its middle third, and the height, weight, and sex of its owner. The study involved 115 metabolically normal people and yielded high correlation coefficients between the calculated and observed total rib cross-sectional areas of 60 males and 55 females. It is suggested that the total cross-sectional area at a standard bone sampling site be used as a basis for normalizing measures of the severity of osteoporosis. This would allow one to make improved comparisons of the severity of osteoporosis between persons of different body habitus and sex.

scholarly journals Numerical simulation of cutting layer in internal corners milling

Mechanik ◽  
2019 ◽  
Vol 92 (7) ◽  
pp. 412-414
Author(s):  
Jan Burek ◽  
Rafał Flejszar ◽  
Barbara Jamuła
Keyword(s):  
Numerical Simulation ◽  
Numerical Model ◽  
Cross Section ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Cross Section Area ◽  
Section Area ◽  
The Cross ◽  
The Stability

The analytical and numerical model of the cross-section of the machined layer in the process of milling of concave rounding is presented. Simulation tests were carried out to determine the cross-sectional area of the cutting layer. A strategy has been developed that allows to increase the stability of the cross-section area of the cutting layer when the mill enters the inner corner area.

Similarity Solution of Freezing or Melting Processes with Variable Thermal Properties

1972 ◽  
Vol 1 (1) ◽  
pp. 51-54
Author(s):  
Sui Lin
Keyword(s):  
Temperature Field ◽  
Thermal Properties ◽  
Phase Boundary ◽  
Similarity Solution ◽  
Universal Function ◽  
Cross Sectional Area ◽  
System Of Equations ◽  
Variable Cross ◽  
Sectional Area ◽  
Cross Sectional

Freezing or melting processes, using substances with variable thermal properties, taking place in a body with variable cross-sectional area, are considered. The method of obtaining the similarity solution involves three steps, 1) transformation of the position coordinate, 2) description of the temperature field, and 3) consideration of the temperature distribution in the neighbourhood of the phase boundary. It reduces the system of equations in the neighbourhood of the phase boundary to one that is independent of the cross-sectional area. The solution of this system is a universal function and is applicable to bodies with different cross-sectional areas. A theorem for calculating the rate of propagation of the phase boundary in a body of variable cross-sectional area from that in a body of constant cross-sectional area is obtained.

scholarly journals Assessing lumbar paraspinal muscle cross-sectional area and fat composition with T1 versus T2-weighted magnetic resonance imaging: Reliability and concurrent validity

PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0244633
Author(s):  
J. R. Cooley ◽  
J. J. Hebert ◽  
A. de Zoete ◽  
T. S. Jensen ◽  
P. R. Algra ◽  
...  
Keyword(s):  
Concurrent Validity ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Resonance Imaging ◽  
Limits Of Agreement ◽  
Cross Sectional ◽  
Rater Reliability ◽  
Lumbar Multifidus ◽  
Total Cross Sectional Area ◽  
Weighted Sequences

Purpose Studies using magnetic resonance imaging to assess lumbar multifidus cross-sectional area frequently utilize T1 or T2-weighted sequences, but seldom provide the rationale for their sequence choice. However, technical considerations between their acquisition protocols could impact on the ability to assess lumbar multifidus anatomy or its fat/muscle distinction. Our objectives were to examine the concurrent validity of lumbar multifidus morphology measures of T2 compared to T1-weighted sequences, and to assess the reliability of repeated lumbar multifidus measures. Methods The lumbar multifidus total cross-sectional area of 45 patients was measured bilaterally at L4 and L5, with histogram analysis determining the muscle/fat threshold values per muscle. Images were later re-randomized and re-assessed for intra-rater reliability. Matched images were visually rated for consistency of outlining between both image sequences. Bland-Altman bias, limits of agreement, and plots were calculated for differences in total cross-sectional area and percentage fat between and within sequences, and intra-rater reliability analysed. Results T1-weighted total cross-sectional area measures were systematically larger than T2 (0.2 cm2), with limits of agreement <±10% at both spinal levels. For percentage fat, no systematic bias occurred, but limits of agreement approached ±15%. Visually, muscle outlining was consistent between sequences, with substantial mismatches occurring in <5% of cases. Intra-rater reliability was excellent (ICC: 0.981–0.998); with bias and limits of agreement less than 1% and ±5%, respectively. Conclusion Total cross-sectional area measures and outlining of muscle boundaries were consistent between sequences, and intra-rater reliability for total cross-sectional area and percentage fat was high indicating that either MRI sequence could be used interchangeably for this purpose. However, further studies comparing the accuracy of various methods for distinguishing fat from muscle are recommended.

scholarly journals Predictive potential of macrophage population phenotyping in malignization of H. pylori-associated chronic gastritis

2021 ◽  
Author(s):  
EP Golubinskaya ◽  
TP Sataieva ◽  
II Fomochkina ◽  
AV Kubyshkin ◽  
TP Makalish ◽  
...  
Keyword(s):  
Tumor Cell ◽  
Blood Vessels ◽  
Chronic Gastritis ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Macrophage Population ◽  
Macrophage Marker ◽  
Total Cross Sectional Area ◽  
H Pylori

Tumor-associated macrophages are able to regulate the tumor cell proliferation and to affect the tumor cell dissemination. The study was aimed to assess the predictive potential of the macrophage population immunohistochemical phenotyping in early malignization of H. pylori-associated chronic gastritis. Gastic biopsy samples of male and female patients aged 48 ± 7.2 infected with Helicobacter pylori were used as the research material. The patients were divided into three groups: non-atrophic chronic gastritis (NACG, n = 10), atrophic chronic gastritis (ACG, n = 10), G1/G2 gastric adenocarcinoma (GAC, n = 10). The macrophage population was visualized using the CD68 pan-macrophage marker and the type 2 monocyte/macrophage marker CD163. Intensity of neoangiogenesis was defined using the CD31 endothelial marker by assessing the total cross sectional area of blood vessels. It was found that chronic gastritis was accompanied by the dynamic increase in the size of the general macrophage population with the progression of atrophic and metaplastic processes. According to immunohistochemical study of biopsies obtained from patients with NCG, the CD163 : CD68 ratio was 0.67 ± 0.02, and the total cross sectional area of blood vessels was 3590.92 ± 356.27 µm2. Atrophic gastritis and adenocarcinoma were characterized by vector redistribution of monocytes/macrophages into the 2nd functional phenotype. The CD163 : CD68 expression index in the group with ACG was 0.81 ± 0.04, and in the group with GAC it was 0.88 ± 0.03. Microvascular area was significantly increased in the groups with ACG and GAC, which reflected tumor neoangiogenesis intensification under the influence of М2 monocytes/macrophages. The increased expression of CD163 can serve as a predictor of chronic gastritis malignization together with evaluation of the glandular epithelium atrophy and metaplasia degree.

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