Comparison of Internal Jugular Vein Cross-Section Area During a Russian Tilt-Table Protocol and Microgravity

2021 ◽  
Vol 92 (3) ◽  
pp. 207-211
Author(s):  
Jason David ◽  
Richard A. Scheuring ◽  
Andrew Morgan ◽  
Cara Olsen ◽  
Ashot Sargsyan ◽  
...  
Keyword(s):  
Internal Jugular Vein ◽  
Cross Section ◽  
Jugular Vein ◽  
Cardiovascular Effects ◽  
Tilt Table ◽  
Cross Sectional ◽  
Cross Section Area ◽  
Section Area ◽  
Training Protocol

BACKGROUND: To date, we lack U.S. data on the effects of the long-used Russian tilt-table training protocol known as the Russian pre-launch tilt-table training protocol on internal jugular vein cross sectional area (IJV-CSA) in microgravity.CASE REPORT: A case study of a single healthy male astronaut volunteer was used for this study. The right IJV-CSA was measured using real time ultrasound at set times throughout the Russian pre-launch tilt-table training protocol, a method of physiological preparation for microgravity using tilt-table training. In microgravity, the subjects right IJV-CSA was measured again for comparison. The mean difference from in-flight right IJV-CSA for pre-tilt (0) was 0.438 cm2, for 15 was 0.887 cm2, for 30 was 0.864 cm2, for 50 was 1.15 cm2, and for post-tilt (0) the difference was 0.305 cm2.DISCUSSION: The cross-sectional areas of the subjects right IJV-CSA were significantly different between in-flight values and several angles of the Russian tilt-table protocol, except for the 0 measurement. In summary, this case-study represents the first time IJV-CSA has been compared between various angles of a tilt-table training protocol and microgravity in the same astronaut subject. The findings support prior cohort studies studying the same principles. Further investigation is merited; both to better describe the relationship between the cardiovascular effects of tilt-table simulations of microgravity and their correlating in-flight values, and to evaluate and study the Russian tilt-table protocol effects on cardiovascular physiology from a training and preparation perspective.David J, Scheuring RA, Morgan A, Olsen C, Sargsyan A, Grishin A. Comparison of internal jugular vein cross-section area during a Russian tilt-table protocol and microgravity. Aerosp Med Hum Perform. 2021; 92(3):207211.

Trendelenburg position for internal jugular vein catheterization: A systematic review and meta-analysis

2021 ◽  
pp. 112972982110313
Author(s):  
Mariana Garcia-Leal ◽  
Santos Guzman-Lopez ◽  
Adrian Manuel Verdines-Perez ◽  
Humberto de Leon-Gutierrez ◽  
Bernardo Alfonso Fernandez-Rodarte ◽  
...  
Keyword(s):  
Systematic Review ◽  
Internal Jugular Vein ◽  
Jugular Vein ◽  
Meta Analysis ◽  
Trendelenburg Position ◽  
Cross Sectional ◽  
Cross Section Area ◽  
Section Area ◽  
Internal Jugular Vein Catheterization ◽  
The Right

To determine the effect of Trendelenburg position on the diameter or cross-section area of the internal jugular vein (IJV) a systematic review and metanalysis was performed. Studies that evaluated the cross-sectional area (CSA) and anteroposterior (AP) diameter of the right internal jugular vein (RIJV) with ultrasonography in supine and any degree of head-down tilt (Trendelenburg position) were analyzed. A total of 22 articles (613 study subjects) were included. A >5° Trendelenburg position statistically increases RIJV CSA and AP diameter. Further inclination from 10° does not statistically benefit IJV size. This position should be recommended for CVC placement, when patient conditions allow it, and US-guided cannulation is not available.

An Analytical Method of Analyzing the Heat Conduction for the Unequal Cross-Section Straight Fin

2013 ◽  
Vol 365-366 ◽  
pp. 1211-1216
Author(s):  
Fan Zhang ◽  
Peng Yun Song
Keyword(s):  
Heat Conduction ◽  
Cross Section ◽  
Analytical Method ◽  
Thermal Analyses ◽  
Cross Sectional ◽  
Cross Section Area ◽  
Section Area ◽  
Calculation Results ◽  
The Cross ◽  
Analytical Expressions

The cross-section area of straight fin is often considered to be equal in the thermal analyses of straight fin, but sometimes it is unequalin actual situation. Taking a straight fin with two unequal cross-sectional areas as an example,an analytical method of heat conduction for unequal section straight fin is presented. The analytical expressions of temperature field and heat dissipating capacity about the fin,which has a smaller cross-section area near the fin base and a larger one, is obtained respectively. The calculation results of the unequal cross-section are fully consistent with the equal area one, so the method is proved right. The results show that the larger the cross section areanear the base,the better is the heat transfer, and the temperature at the base with larger cross-section area is lower than that with smaller cross-section area when the amount of heat is fixed.

scholarly journals Load bearing capacity of thin-walled rectangular and I-shaped steel sections of short both empty and concrete-filled columns

2021 ◽  
Vol 15 (58) ◽  
pp. 77-85
Author(s):  
Amor Bouaricha ◽  
Naoual Handel ◽  
Aziza Boutouta ◽  
Sarah Djouimaa
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Load Capacity ◽  
Cross Sectional ◽  
Short Columns ◽  
Cross Section Area ◽  
Section Area ◽  
Specimen Height ◽  
Steel Sections ◽  
Thin Walled

In this experimental work, strength results obtained on short columns subjected to concentric loads are presented. The specimens used in the tests have made of cold-rolled, thin-walled steel. Twenty short columns of the same cross-section area and wall thickness have been tested as follows: 8 empty and 12 filled with ordinary concrete. In the aim to determine the column section geometry with the highest resistance, three different types of cross-sections have been compared: rectangular, I-shaped unreinforced and, reinforced with 100 mm spaced transversal links. The parameters studied are the specimen height and the cross-sectional steel geometry. The registered experimental results have been compared to the ultimate loads intended by Eurocode 3 for empty columns and by Eurocode 4 for compound columns. These results showed that a concrete-filled composite column had improved strength compared to the empty case. Among the three cross-section types, it has been found that I-section reinforced is the most resistant than the other two sections. Moreover, the load capacity and mode of failure have been influenced by the height of the column. Also, it had noted that the experimental strengths of the tested columns don’t agree well with the EC3 and EC4 results.

scholarly journals Exact Longitudinal Vibration Characteristics of Rods with Variable Cross-Sections

2011 ◽  
Vol 18 (4) ◽  
pp. 555-562 ◽  
Author(s):  
Bulent Yardimoglu ◽  
Levent Aydin
Keyword(s):  
Differential Equation ◽  
Cross Section ◽  
Cross Sections ◽  
Longitudinal Vibration ◽  
Transformation Method ◽  
Variable Cross ◽  
Cross Sectional ◽  
Cross Section Area ◽  
Section Area ◽  
Sinusoidal Functions

Longitudinal natural vibration frequencies of rods (or bars) with variable cross-sections are obtained from the exact solutions of differential equation of motion based on transformation method. For the rods having cross-section variations as power of the sinusoidal functions ofax+b, the differential equation is reduced to associated Legendre equation by using the appropriate transformations. Frequency equations of rods with certain cross-section area variations are found from the general solution of this equation for different boundary conditions. The present solutions are benchmarked by the solutions available in the literature for the special case of present cross-sectional variations. Moreover, the effects of cross-sectional area variations of rods on natural characteristics are studied with numerical examples.

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.

Comparative Study of Steel Beam Column Connection under Cyclic Loading

2016 ◽  
Vol 857 ◽  
pp. 53-58
Author(s):  
S. Anisha ◽  
Dhanya Krishnan
Keyword(s):  
Cross Section ◽  
Plastic Hinge ◽  
Steel Beam ◽  
Cross Sectional ◽  
Reduced Beam Section ◽  
Cross Section Area ◽  
Section Area ◽  
Beam Section ◽  
The Cross ◽  
Stress And Deformation

A structure is an assembly of various elements or components which are fastened together through some type of connections. Steel beam column connection may fail due to large earth quake. Plastic hinge formation is the main failure of a steel beam column connection. There are two methods for improving the steel beam column connection (i) connection reinforcement/strengthening (ii) beam weakening by reducing the cross-sectional area of the beam at a certain distance from the connection. When reducing the cross section area plastic hinge is formed away from column face. The main objective of this study is to compare reduced beam section (RBS) and reduced web section (RWS) pattern and find out the location of plastic hinge. For steel beam column plastic hinge is located near column. When reducing the cross section area the location of plastic hinge will shift from the column. Aim of this project is to locate the position of plastic hinge apart from column face, and also evaluate the stress and deformation.

scholarly journals Klein Nishina Differential Equation for the Selection of Radiation Shielding Material (C, AL, Fe, and Zn) on the Basis of Attenuation and Cross sectional Area

2021 ◽  
Vol 3 (1) ◽  
pp. 30-35
Author(s):  
Saddam Husain Dhobi ◽  
Santosh Kumar Das ◽  
Kishori Yadav
Keyword(s):  
Differential Equation ◽  
Cross Section ◽  
Radiation Shielding ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Protective Material ◽  
Cross Sectional ◽  
Cross Section Area ◽  
Section Area ◽  
Aluminum Iron

On studying the Electronic and Atomic Cross sectional area for low atomic masses (Carbon, Aluminum, Iron and Zinc) using Klien-Nishina differential equation. The atomic cross section among these elements for same energy of incidence photon the atomic cross section area found on order of Carbon Aluminum Iron Zinc. This show with increasing atomic number and mass the cross section area of material goes increase. But the mass attenuation goes decrease with increasing in mass and number of materials made up of high atomic weight and number. This is clearly seen in Fig. 2 and Fig. 3. Therefore, among these elements protective material is made up of Carbon has more safety than other (Al, Fe, Zn).

scholarly journals Influence of the are of the channel's cross-section area on the critical speed of navigation

Tehnika ◽  
2020 ◽  
Vol 75 (6) ◽  
pp. 629-635
Author(s):  
Ivan Škiljaica ◽  
Vladimir Škiljaica
Keyword(s):  
Cross Section ◽  
Critical Speed ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Channel Network ◽  
Cross Sectional ◽  
Cross Section Area ◽  
Section Area

Research presented in the paper refer to calculation of the influence of navigable channel's cross-section area, which belong to the Danube-Tisza-Danube (DTD) system, on critical speed of navigation of ships. During research relation between area of the channel's cross-section of certain sections of the channel on creating critical speed of navigation for one type of cargo ship of Serbian shipping companies which was designed for navigation on the channel network of the DTD system. It is known that the value of the first critical speed (vkr(1)), presents the base to determine the allowed speed of navigation (vpl) for the ship of known geometric and exploitation characteristic in the channel of known cross-sectional area (OK) with precisely defined dimensions.

MECHANICAL CHARACTERISTICS OF THE MATERIAL OF ADDITIVE STRUCTURES WITH DIFFERENT METHODS FOR DETERMINING THE CROSS-SECTION AREA OF SPECIMENS

2021 ◽  
pp. 74-89
Author(s):  
А. Ю. Перелыгина ◽  
Т. Я. Дружинина ◽  
С. А. Антипин ◽  
Ю. А. Бобылева
Keyword(s):  
3D Printing ◽  
Cross Section ◽  
Mechanical Characteristics ◽  
Sectional Area ◽  
Cross Sectional ◽  
Cross Section Area ◽  
Section Area ◽  
Material Homogeneity ◽  
Printing Parameters ◽  
Central Tension

В статье рассматривается вопрос определения механических характеристик материала аддитивных структур с учетом таких параметров печати, как процент заполнения и направление нитей печати. В исследованиях использовались три типоразмера стандартизированных образцов на центральное растяжение, изготовленных с применением технологии 3D-печати. В ходе экспериментов было установлено, что при определении механических характеристик материала необходимо отходить от гипотезы однородности и сплошности материала, принятой в сопротивлении материалов. Для определения значений механических характеристик у образцов разных типоразмеров была предложена методика по расчету реальной площади поперечного сечения исследуемой структуры. В статье приведены диаграммы растяжения и рассчитанные по ним механические характеристики материала аддитивных структур, а также рассмотрен вопрос влияния отношения площади структуры к площади ограждения на механические характеристики материала. The article discusses the issue of determining the mechanical characteristics of the material of additive structures, taking into account such printing parameters as the percentage of filling and the direction of the printing filaments. The studies used three sizes of standardized specimens for central tension, made using 3D printing technology. During the experiments, it was found that when determining the mechanical characteristics of a material, it is necessary to deviate from the hypothesis of material homogeneity and continuity, adopted in the strength of materials. To determine the values of mechanical characteristics for samples of different sizes, a technique was proposed for calculating the real cross-sectional area of the structure under study. The article presents tensile diagrams and the mechanical characteristics of the material of additive structures calculated from them, as well as the issue of the influence of the ratio of the structure area to the perimeter area on the mechanical characteristics of the material.

scholarly journals Sonographic parameters of the pancreas and gall bladder in healthy men from Podillya region of Ukraine of different somatotypes

2016 ◽  
Vol 29 (2) ◽  
pp. 94-96 ◽  
Author(s):  
Igor Gunas ◽  
Sergiy Prokopenko ◽  
Marina Melnik
Keyword(s):  
Gall Bladder ◽  
Cross Section ◽  
Tail Length ◽  
The Body ◽  
Longitudinal Cross Section ◽  
Cross Sectional ◽  
Healthy Men ◽  
Cross Section Area ◽  
Section Area ◽  
Area And Volume

Abstract In this work, we undertook a study of the sonographic parameters of the pancreas and gall bladder in healthy men with different somatotypes. The study-subjects were from the Podillya region of Ukraine. Herein, the majority of gallbladder dimensions (length, thickness, cross-sectional area and volume) in men type-classified as endo-mesomorphic, were significantly higher when compared with men in general and with those of the meso- and ecto-mesomorphic somatotype. Furthermore, the dimensions of the pancreas (width of head and tail length) in mesomorphic males were significantly higher than that of endo-mesomorphic males. The rest of the studied parameters (length, longitudinal cross section area of the gall bladder, the thickness of the head, body and head length, the width of the body and tail of the pancreas) in men of the different somatotypes have no significant differences.

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