206 Numerical Simulation of Magnetically Suspended Centrifugal Blood Pump : The internal flow due to the difference in cross-sectional area of the volute

2013 ◽  
Vol 2013.88 (0) ◽  
pp. _2-6_
Author(s):  
Takurou MATSUMOTO ◽  
Toshihide NONAKA ◽  
Masaaki HORIE ◽  
Yoshifumi OGAMI
Keyword(s):  
Numerical Simulation ◽  
Internal Flow ◽  
Cross Sectional Area ◽  
Blood Pump ◽  
Sectional Area ◽  
Cross Sectional ◽  
Centrifugal Blood Pump ◽  
The Difference

scholarly journals Comparison of Muscle Cross-sectional Area and Lumbar Muscle Strength According to Degenerative Spinal Diseases

2020 ◽  
Vol 22 (2) ◽  
pp. 1-10
Author(s):  
Ji-Hoon Cho ◽  
Ki-Hyuk Lee ◽  
Seung-Taek Lim ◽  
Buong-O Chun
Keyword(s):  
Muscle Strength ◽  
Cross Sectional Area ◽  
Spinal Diseases ◽  
Sectional Area ◽  
Multifidus Muscle ◽  
Cross Sectional ◽  
Total Group ◽  
Male Group ◽  
The Difference ◽  
Lumbar Extension

OBJECTIVES The purpose of this study was to investigate the difference in the cross - sectional area (CSA) of multifidus and Iliopsoas muscles and the lumbar extension muscle strength according to degenerative spinal diseases (LHI; lumbar herniation of intervertebral disc group, SS; spinal stenosis group, S; spondylolisthesis group).METHODS The CSA of multifidus and Iliopsoas muscles size were measured by PACS(Picture Achiving and Communication System) using MRI at the L4/5 level and lumbar extension muscle strength (72˚, 60˚, 48˚, 36˚, 24˚, 12˚, 0˚) was measured using lumbar extension machine(MedX) in 97 patients of degenerative spinal diseases(male: 57, female: 40). The collected data were analyzed by one-way ANOVA using the SPSS program.RESULTS The results of this study showed that the CSA of total and right multifidus muscle in the LHI was significantly higher than that of the S (p <.05; p <.05) in the male group. The difference between the left and right CSA of multifidus in the LHI group was significantly higher than that of the SS (p <.05) in the male group (p <.05) and total group (p <.05). The CSA of iliopsoas muscle in the S was significantly higher than that of the LHI in the male and total group (p <.05; p <.05). In case of lumbar extension muscle strength, the S showed significantly higher muscle strength at 36 and 48 degrees than that of the SS in the male group. In the total group, LHI showed significantly higher muscle strength at 60 degrees of lumbar extension muscle strength than that of the S.CONCLUSION Multifidus muscle appears to be a key factor in prevention and treatment intervention in low back pain patients. In particular, in the case of S group, exercise therapy for strengthening the multifidus muscle is need for the rehabilitation.

Maintenance of myonuclear domain size in rat soleus after overload and growth hormone/IGF-I treatment

1998 ◽  
Vol 84 (4) ◽  
pp. 1407-1412 ◽  
Author(s):  
G. E. McCall ◽  
D. L. Allen ◽  
J. K. Linderman ◽  
R. E. Grindeland ◽  
R. R. Roy ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Domain Size ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Muscle Weight ◽  
Cross Sectional ◽  
Igf I ◽  
Myonuclear Domain ◽  
The Difference ◽  
Saline Vehicle

The purpose of this study was to determine the effects of functional overload (FO) combined with growth hormone/insulin-like growth factor I (GH/IGF-I) administration on myonuclear number and domain size in rat soleus muscle fibers. Adult female rats underwent bilateral ablation of the plantaris and gastrocnemius muscles and, after 7 days of recovery, were injected three times daily for 14 days with GH/IGF-I (1 mg/kg each; FO + GH/IGF-I group) or saline vehicle (FO group). Intact rats receiving saline vehicle served as controls (Con group). Muscle wet weight was 32% greater in the FO than in the Con group: 162 ± 8 vs. 123 ± 16 mg. Muscle weight in the FO + GH/IGF-I group (196 ± 14 mg) was 59 and 21% larger than in the Con and FO groups, respectively. Mean soleus fiber cross-sectional area of the FO + GH/IGF-I group (2,826 ± 445 μm2) was increased compared with the Con (2,044 ± 108 μm2) and FO (2,267 ± 301 μm2) groups. The difference in fiber size between the FO and Con groups was not significant. Mean myonuclear number increased in FO (187 ± 15 myonuclei/mm) and FO + GH/IGF-I (217 ± 23 myonuclei/mm) rats compared with Con (155 ± 12 myonuclei/mm) rats, although the difference between FO and FO + GH/IGF-I animals was not significant. The mean cytoplasmic volume per myonucleus (myonuclear domain) was similar across groups. These results demonstrate that the larger mean muscle weight and fiber cross-sectional area occurred when FO was combined with GH/IGF-I administration and that myonuclear number increased concomitantly with fiber volume. Thus there appears to be some mechanism(s) that maintains the myonuclear domain when a fiber hypertrophies.

scholarly journals A Comparison of the Arithmetic and Geometric Means in Estimating Stump Diameter, Basal Area, and Volume in Appalachian Hardwoods

2007 ◽  
Vol 24 (1) ◽  
pp. 71-73 ◽  
Author(s):  
Harry V. Wiant ◽  
John R. Brooks
Keyword(s):  
Geometric Mean ◽  
Basal Area ◽  
Cross Sectional Area ◽  
Practical Significance ◽  
Sectional Area ◽  
Cross Sectional ◽  
Geometric Means ◽  
The Difference ◽  
Appalachian Hardwoods ◽  
Stump Diameter

Abstract The difference between the use of the arithmetic and geometric means for estimation of average stump diameter, stump cross-sectional area and estimated tree volume was investigated using measurements from 739 stumps from an Appalachian hardwood stand located in central West Virginia. Although average stump diameter, cross-sectional area, and tree volumes were statistically different between estimates based on the arithmetic and geometric mean diameter, these differences were of little practical significance. The difference in average stem diameter, cross-sectional area, tree cubic volume, and board foot volume were 0.05 in, 0.01 ft2, 0.45 ft3, and 2.41 bd ft, respectively.

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.

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.

scholarly journals On a method of determining the viscosity of gases, especially those available only in small quantities

1910 ◽  
Vol 83 (562) ◽  
pp. 265-276 ◽  
Keyword(s):  
Volume Content ◽  
Capillary Tube ◽  
Cross Sectional Area ◽  
The Other ◽  
Sectional Area ◽  
Cross Sectional ◽  
Fine Capillary ◽  
The Difference ◽  
Absolute Measurements ◽  
Unlimited Amount

The apparatus about to be described was designed for the purpose of comparing the viscosities of neon, xenon, and krypton—the loan of which Sir William Ramsay kindly offered the author—with that of air. With such small quantities of gas available, the volume content of the apparatus must obviously be correspondingly small, and therefore, it would seem, unsuitable for absolute measurements. The object of the present paper is to show that this is by no means the case. As will be seen later, the method is actually restricted to small quantities by the conditions of the experiments, but there is no reason why it should not be used even when the gas under test may be obtained in practically unlimited amount. Theory of the Method . Consider a closed glass vessel (as in fig. 1) consisting of two connected limbs, one a fine capillary tube and the other of much greater cross-sectional area, yet sufficiently narrow for a pellet of mercury to remain intact in it. Let V be the volume unoccupied by mercury (the volume of the capillary tube being considered negligible). Let P denote the steady pressure of the gas in the tube when the latter is held horizontally, and let p be the difference of pressure caused by the mercury pellet when the apparatus is vertical. Let p 1 be the pressure and v 1 the volume at any time above the mercury, and p 2 , v 2 , the corresponding quantities below the mercury. Then V = v 1 + v 2 , and p 2 - p 1 = p .

The Skeleton of Giraffes

2021 ◽  
pp. 342-381
Author(s):  
Graham Mitchell
Keyword(s):  
Cervical Vertebrae ◽  
Lumbar Vertebrae ◽  
Average Density ◽  
Cross Sectional Area ◽  
Thoracic Vertebrae ◽  
Sectional Area ◽  
Average Chemical Composition ◽  
Cross Sectional ◽  
Limb Bones ◽  
The Difference

The giraffe skeleton consists of ~170 bones. The dry mass of the skeleton is 70 g.kg-1 body mass. The average chemical composition of their bones is 33% minerals (mainly calcium and phosphorus in a ratio of 2:1), 34% collagen, and 33% water. The skull contributes ~10%, the vertebrae ~25% and the limb bones ~65% to skeleton mass. The average density of all bones is 1.6 g cm-3, ranging from 0.8 g cm-3 (cervical vertebrae) to 2.0 g cm-3 (limb bones). Resistance to fracture by vertebrae depends on their cross-sectional area, and is greatest in cervical and the first few thoracic vertebrae. Resistance to fracture by limb bones depends on wall thickness (the difference between inner and outer diameter), which is uniquely thick. The growth of all limb bones except the humerus follows a geometric pattern (length and diameter increase at the same rate) which confers resistance to compression stress. The humerus follows an elastic pattern (diameter increases faster than length) a pattern that resists bending stress. Giraffes bones are exceptionally straight which further reduces bending stresses. The torque generated by the mass of the head and neck is resisted by the ligamentum nuchae which is exceptionally well-developed in giraffes, extends from the lumbar vertebrae to the occipital crest, can have a diameter of ~10 cm, and can support loads of ~1.8 tonnes before rupturing. As a giraffe grows muscle cross-sectional area (and contraction strength) declines and the duty factor reduces, both of which reduce the risk of fracture.

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