Radiation Technique for the Measurement of External Diameter and Wall Thickness of Glass Tubing

1973 ◽  
Vol 6 (5) ◽  
pp. 187-189
Author(s):  
Mgr Mieczysław Dziura
Keyword(s):  
Wall Thickness ◽  
External Diameter ◽  
Glass Tubing ◽  
Radiation Technique

scholarly journals To Estimate the Importance of Wharton’s Jelly in the Growth of the Foetus – A Light Microscopic Study

2021 ◽  
Vol 10 (35) ◽  
pp. 3024-3029
Author(s):  
Sreekumar Rajasekharan ◽  
UmesanKannanvilakom Govindapillai ◽  
Manju Madhavan C. ◽  
Suja R. S. ◽  
Swapna T ◽  
...  
Keyword(s):  
Umbilical Cord ◽  
Wall Thickness ◽  
Umbilical Artery ◽  
Umbilical Vein ◽  
Wharton’S Jelly ◽  
External Diameter ◽  
Single Umbilical Artery ◽  
Wharton's Jelly ◽  
Significant Difference ◽  
The Mean

BACKGROUND Human umbilical cord contains two arteries and one vein with their tunica intima and tunica media layers. The role of tunica adventitia is fulfilled by Wharton’s jelly, a mucoid connective tissue. The function of Wharton’s jelly is to prevent the vessels from compression and torsion which is essential for foetal development. The purpose of the study was to estimate the importance of Wharton’s jelly in the growth of the foetus. METHODS Umbilical cord tissue collected from each case was immediately put in 10 % formalin for fixation. Slides were then stained with Haematoxylin and Eosin. These slides were then read under light microscopy and measurements were taken using a photomicrograph. Wharton’s jelly area was calculated by subtracting the total vessel area from the umbilical cord area. RESULTS The histological measurements of umbilical vessels include the external diameter, lumen diameter, wall thickness, thickness of tunica intima and tunica media, and the area. The mean area of the umbilical cord was 35.73 ±23.04 mm2 (Mean ± SD) and the mean area of the Wharton’s jelly was 29.74 ± 19.26 mm2. There was a significant difference in the external diameter and wall thickness of the umbilical artery. Analyses showed that there was a significantly (P < 0.01) increased external diameter and wall thickness of umbilical artery in normal cases, compared to single umbilical artery cases. CONCLUSIONS There was a significant positive correlation between the gestational age and the external diameter of the umbilical cord. There was a significant difference in the external diameter of the umbilical cord between SUA cases (4.45 mm) and the other foetuses with normal umbilical cord (6.53 mm). There was a significantly increased external diameter, lumen diameter, wall thickness and area of umbilical vein in normal cases, compared to single umbilical artery cases. There was a significantly increased area of umbilical cord and area of Wharton’s jelly in normal umbilical cord foetuses than foetuses with a single umbilical artery. KEY WORDS Foetus, Umbilical Cord, Wharton’s Jelly, Umbilical Artery, Umbilical Vein, Light Microscopy

Study of the process of formation of tubes end sections during longitudinal rolling in grooves formed by a different number of rolls

2021 ◽  
pp. 44-48
Author(s):  
D. A. Akhmerov ◽  
◽  
A. V. Vydrin ◽  
Keyword(s):  
Wall Thickness ◽  
Stretch Ratio ◽  
External Diameter ◽  
Continuous Rolling ◽  
Elongation Ratio ◽  
Longitudinal Rolling ◽  
Rolling Mills ◽  
Advantages And Disadvantages ◽  
Hollow Billets ◽  
The Relationship

The work substantiates the relevance and highlights the degree of development of the research topic. The main advantages and disadvantages of the process of rolling hollow billets with the use of modern longitudinal rolling mills with 2 and 3 roll grooves are noted. With the help of physical and computer modeling, a study of the process of longitudinal rolling of pipes using 2 and 3 roll passes was carried out, for the formation of end sections (scrap). Established and numerically reflected the relationship between the size of the reduction of passes of a continuous rolling mill with 3-roll and 2-roll stands and the length of the end sections of the pipes. It is clear that the use of 3 rolls, forming a groove, allows to reduce the total end cut by 1.5 times, in contrast to 2 rolls. It has been determined that the main technological factors influencing the formation of the end sections are the ratio of the external diameter to the wall thickness of the strip (D/S), the reduction along the wall thickness, the elongation ratio, and the number of rolls required to form the groove. An empirical formula has been obtained for calculating the length of the end trim, which makes it possible to evaluate the influence of the number of rolls in the stand, the D/S ratio and the stretch ratio.

Pressure-diameter relations of excised aorta

1962 ◽  
Vol 202 (6) ◽  
pp. 1166-1170 ◽  
Author(s):  
John W. Remington
Keyword(s):  
Wall Thickness ◽  
Abdominal Aorta ◽  
Vessel Wall ◽  
External Diameter ◽  
Static Stretch ◽  
Wall Thinning ◽  
Wall Extensibility

A length of abdominal aorta was excised, and volume pulses were made at different pressure values by volume injections. The expected diameter changes were calculated from a static stretch curve made from a ring cut from the vessel. External diameter changes were recorded by a transformer coil. The two sets of data could be compared only after calculating the expected changes in wall thickness. Agreement was good enough to conclude that both techniques could measure wall extensibility. When the vessel was elongated to the in situ length, the external diameter showed an appreciable decrease. If wall volume was constant, this could be accounted for by a wall thinning. With such elongation, circumferential extensibility was clearly decreased. The vessel wall was almost isotropic at pressure values above 50 mm Hg, but at lower pressures it showed evidence of an architectural nonhomogeneity in its stretch behavior.

Collapse Propagation of Deep Water Pipelines

2017 ◽  
Author(s):  
Ana Paula França de Souza ◽  
Rafael F. Solano ◽  
Fabio B. de Azevedo ◽  
Erwan Karjadi ◽  
Caroline Ferraz
Keyword(s):  
Wall Thickness ◽  
Oil And Gas ◽  
Oil And Gas Industry ◽  
External Pressure ◽  
External Diameter ◽  
Gas Industry ◽  
Deep Waters ◽  
Water Pipelines ◽  
Offshore Oil And Gas ◽  
Pipeline Design

Nowadays, the global trend is an increasing need for oil and gas. As the easily recoverable fields have been already developed, the trend in the offshore oil and gas industry is going deeper into the more challenging outlook, such as outside West Africa, the Brazilian Pre-Salt developments and in the Gulf of Mexico. For ultra-deep waters the main design challenge is related to the high external pressure that may cause collapse of pipelines. This potential failure mode is normally dealt with by increasing the pipe wall thickness, but at ultra-deep waters this may require very thick pipe that becomes very costly, difficult to manufacture and hard to install due to its weight. Facing the challenges of the pipeline design for ultra-deep waters, the Collapse Joint Industry Project (JIP) was started to develop a guideline for wall thickness design optimization for offshore pipelines with external diameter to wall thickness ratio less than 20 (D/t < 20). As part of the JIP, nine buckle propagation tests were conducted on full scale seamless pipes. This paper describes these experiments and new conclusions that were raised in light of the test results.

ALGORITHM FOR EXAMINING PATIENTS WITH PATHOLOGY OF THE UPPER GASTROINTESTINAL TRACT USING MULTISPIRAL COMPUTED TOMOGRAPHY

2021 ◽  
pp. 18-32
Author(s):  
Anastasiya N. Dmitrieva
Keyword(s):  
Computed Tomography ◽  
Gastrointestinal Tract ◽  
Wall Thickness ◽  
Normal Condition ◽  
Threshold Value ◽  
Esophageal Wall ◽  
External Diameter ◽  
Light Speed ◽  
Chuvash Republic ◽  
Upper Gastrointestinal

The aim of the study was to develop a technique for conducting multispiral computed tomography (MSCT) when examining the upper parts of the gastrointestinal tract. A prospective analysis of MSCT images was performed in 85 people who were examined at the AI "Republican Clinical Oncology Dispensary" under the Ministry of Public Health of the Chuvash Republic in 2015-2019. All patients underwent computed tomography using Light Speed VEX Plus and Light Speed RT 16 devices ("GE", USA) using our modified esophageal and gastric MSCT technique with an emphasis on the esophageal-gastric junction (EGJ). The characteristic quantitative MSCT-signs of the esophageal wall, the stomach, and the EGJ area in the norm, as well as the ones in an abnormal esophageal wall in esophagitis and gastritis are presented. The esophageal wall thickness in the normal condition and esophagitis was 3.12±0.69 mm and 8.16±1.65 mm (p = 0.000, R=0.909), and the maximum external diameter of the abdominal part of esophagus was 14.2±1.68 mm and 17.96±3.7 mm (p = 0.000, R = 0.579), respectively. The ROC analysis revealed a threshold value equal to 5.5 mm for distinguishing the wall thickness values characteristic for the unchanged esophagus and the esophagus with inflammatory pathology (sensitivity-96%, specificity-100%, p = 0.000). The threshold value for the external diameter of the abdominal esophageal segment was 17.5 mm (sensitivity – 64%, specificity – 100%, p = 0.000). The thickness of the stomach wall in the normal condition and in gastritis made 4.6±0.48 mm and 7.52±2.71 mm (p = 0.000, R = 0.673), respectively. At this, the threshold value of this characteristic was equal to 5.5 mm (sensitivity – 87.1%, specificity – 100%). The wall thickness in the area of the cardia in the normal condition was 5.4±1.01 mm, in presence of inflammation – 10.36±1.85 mm (p = 0.000, R = 0.858), the threshold value – 7.5 mm (sensitivity – 95.83%, specificity – 98.04%, p = 0.000). The thickness of individual layers in the unchanged stomach walls did not exceed 2 mm, the thickness of the mucosa was 1.01±0.11 mm.

Exercise-induced cardiac hypertrophy is associated with an increased myocardial compliance

1995 ◽  
Vol 78 (4) ◽  
pp. 1303-1311 ◽  
Author(s):  
A. J. Woodiwiss ◽  
G. R. Norton
Keyword(s):  
Exercise Training ◽  
Cardiac Hypertrophy ◽  
Wall Thickness ◽  
Diastolic Pressure ◽  
Left Ventricular ◽  
External Diameter ◽  
Myocardial Wall ◽  
Diastolic Stiffness ◽  
Strain Relationship ◽  
Exercise Induced

Left ventricular (LV) chamber and myocardial wall compliance were investigated in rats with exercise-induced cardiac hypertrophy. Voluntary exercise training was performed on running wheels. After 16 wk of exercise training, cardiac performance was measured in anesthetized open-chest ventilated rats. LV end-diastolic performance was calculated from both short-axis external diameter and long-axis segmental length measurements. Exercise-trained rats developed significant LV hypertrophy (1.03 +/- 0.02 g) compared with control rats (0.91 +/- 0.03 g; P < 0.01). The physiological hypertrophy was associated with an increased LV wall thickness-to-internal radius ratio consistent with a concentric geometry. LV end-diastolic stiffness (slope of the linearized LV end-diastolic pressure-strain relationship) was decreased in both the short (P < 0.02) and long (P < 0.02) axis of LV as a result of exercise training. The LV end-diastolic chamber stiffness (slope of the linearized LV end-diastolic pressure-volume relationship) was also decreased in the exercised group (P < 0.05). The decreased chamber stiffness occurred as a consequence of a decrease in the regional myocardial wall elastic stiffness (slope of the linearized LV end-diastolic stress-strain relationship; P < 0.05). Thus an increased LV wall thickness as a result of exercise-induced LV hypertrophy is associated with an enhanced ventricular chamber compliance, which in turn is attributed to a decrease in the diastolic stiffness of the myocardial wall.

Biomechanical proprieties of decellularized porcine common carotid arteries

2005 ◽  
Vol 289 (4) ◽  
pp. H1567-H1576 ◽  
Author(s):  
Sylvain Roy ◽  
Paolo Silacci ◽  
Nikolaos Stergiopulos
Keyword(s):  
Elastic Modulus ◽  
Wall Thickness ◽  
Carotid Arteries ◽  
Biomechanical Properties ◽  
Internal Diameter ◽  
External Diameter ◽  
Before And After ◽  
High Inflation ◽  
And Control ◽  
Common Carotid Arteries

To analyze the effects of decellularization on the biomechanical properties of porcine common carotid arteries, decellularization was performed by a detergent-enzymatic procedure that preserves extracellular matrix scaffold. Internal diameter, external diameter, and wall thickness were measured by optical microscopy on neighboring histological sections before and after decellularization. Rupture tests were conducted. Inner diameter and wall thickness were measured by echo tracking during pressure inflation from 10 to 145 mmHg. Distensibility and incremental elastic modulus were computed. At 10 mmHg, mean diameter of decellularized arteries was 5.38 mm, substantially higher than controls (4.1 mm), whereas decellularized and control arteries reached the same internal diameter (6.7 mm) at 145 mmHg. Wall thickness decreased 16% for decellularized and 32% for normal arteries after pressure was increased from 10 to 145 mmHg. Decellularized arteries withstood pressure >2,200 mmHg before rupture. At 145 mmHg, decellularization reduced compliance by 66% and increased incremental elastic modulus by 54%. Removal of cellular elements from media led to changes in arterial dimensions. Collagen fibers engaged more rapidly during inflation, yielding a stiffer vessel. Distensibility was therefore significantly lower (by a factor of 3) in decellularized than in normal vessels: reduced in the physiological range of pressures. In conclusion, decellularization yields vessels that can withstand high inflation pressures with, however, markedly different geometrical and biomechanical properties. This may mean that the potential use of a decellularized artery as a scaffold for the creation of xenografts may be compromised because of geometrical and compliance mismatch.

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