scholarly journals CONTROL OF WETTING PROPERTIES OF THE ARTIFICIAL VESSELS SURFACES

2019 ◽  
pp. 25-31
Author(s):  
M. M. Chuiko ◽  
L. A. Vytvytska ◽  
Z. Ya. Vytvytskyi ◽  
H. Z. Lavruk ◽  
B. S. Beregnickii
Keyword(s):  
Blood Coagulation ◽  
Flow Rate ◽  
Test Sample ◽  
Impedance Method ◽  
Bottom Plate ◽  
Coagulation Rate ◽  
Wetting Properties ◽  
In Series ◽  
The Relationship ◽  
Inclined Surface

The influence of the surface properties of different solid materials on the process of blood flowing through them is analyzed. Based on the dependence of the blood coagulation rate on the wetting properties of the solid surfaces on which it spreads, the urgency of developing an express method of controlling the process of blood wetting of the artificial vessels surfaces to prevent thrombosis is substantiated. The adhesion work which is consumed of blood drainage is determined. The impedance method was developed, which is based on the relationship between the flow rate and the change in impedance The impedance method was developed, which is based on the relationship between the flow rate and the change in impedance of the flat capacitor, between the plates of which is the investigated system blood – implant. The interelectrode space of the cell (the investigated system) can be considered as a heterogeneous dielectric, which is a collection of blood, air, and implant samples. Each of these layers can be represented by a set of capacitors and resistors in parallel and connected in series. In the course of blood drainage on the inclined surface of the test sample of implant material, which is located on the bottom plate of the condenser, the redistribution of blood layers, air and sample of the implant occurs, that is, the dielectric constant of the electrode medium changes. The design of the device implementing the impedance method and the results of laboratory tests are presented. Graphic dependencies for establishing the wetting degree of blood the most used materials in the creation of artificial vessels, which confirmed the need for special coatings to increase the blood coagulation time.

An evaluation of ECT sample height for small flute board grades and Box Manufacturer’s Certification compliance

TAPPI Journal ◽  
2009 ◽  
Vol 8 (6) ◽  
pp. 24-28
Author(s):  
CORY JAY WILSON ◽  
BENJAMIN FRANK
Keyword(s):  
Compressive Strength ◽  
Compressive Load ◽  
Test Sample ◽  
Test Methods ◽  
Test Method ◽  
Initial Development ◽  
Sample Height ◽  
Relationship Of ◽  
The Relationship ◽  
Corrugated Fiberboard

TAPPI test T811 is the specified method to ascertain ECT relative to box manufacturer’s certification compliance of corrugated fiberboard under Rule 41/ Alternate Item 222. T811 test sample heights were derived from typical board constructions at the time of the test method’s initial development. New, smaller flute sizes have since been developed, and the use of lighter weight boards has become more common. The T811 test method includes sample specifications for typical A-flute, B-flute, and C-flute singlewall (and doublewall and triplewall) structures, but not for newer thinner E-flute or F-flute structures. This research explores the relationship of ECT sample height to measured compressive load, in an effort to determine valid E-flute and F-flute ECT sample heights for use with the T811 method. Through this process, it identifies challenges present in our use of current ECT test methods as a measure of intrinsic compressive strength for smaller flute structures. The data does not support the use of TAPPI T 811 for ECT measurement for E and F flute structures, and demonstrates inconsistencies with current height specifi-cations for some lightweight B flute.

scholarly journals Neural network-based modeling of the number of microbubbles generated with four circulation factors in cardiopulmonary bypass

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Satoshi Miyamoto ◽  
Zu Soh ◽  
Shigeyuki Okahara ◽  
Akira Furui ◽  
Taiichi Takasaki ◽  
...  
Keyword(s):  
Cardiopulmonary Bypass ◽  
Flow Rate ◽  
Neurological Complications ◽  
Estimation Accuracy ◽  
Model Parameters ◽  
Perfusion Flow ◽  
Postsurgical Complication ◽  
Tenfold Cross Validation ◽  
Suction Flow ◽  
The Relationship

AbstractThe need for the estimation of the number of microbubbles (MBs) in cardiopulmonary bypass surgery has been recognized among surgeons to avoid postoperative neurological complications. MBs that exceed the diameter of human capillaries may cause endothelial disruption as well as microvascular obstructions that block posterior capillary blood flow. In this paper, we analyzed the relationship between the number of microbubbles generated and four circulation factors, i.e., intraoperative suction flow rate, venous reservoir level, continuous blood viscosity and perfusion flow rate in cardiopulmonary bypass, and proposed a neural-networked model to estimate the number of microbubbles with the factors. Model parameters were determined in a machine-learning manner using experimental data with bovine blood as the perfusate. The estimation accuracy of the model, assessed by tenfold cross-validation, demonstrated that the number of MBs can be estimated with a determinant coefficient R2 = 0.9328 (p < 0.001). A significant increase in the residual error was found when each of four factors was excluded from the contributory variables. The study demonstrated the importance of four circulation factors in the prediction of the number of MBs and its capacity to eliminate potential postsurgical complication risks.

scholarly journals The Transport of Salt and Water across Isolated Rat Ileum

1967 ◽  
Vol 50 (3) ◽  
pp. 695-727 ◽  
Author(s):  
T. W. Clarkson
Keyword(s):  
Active Transport ◽  
Transport Processes ◽  
Irreversible Processes ◽  
Pressure Gradients ◽  
Ion Flow ◽  
Chemical Gradients ◽  
In Series ◽  
Frictional Coefficients ◽  
The Relationship ◽  
Active Channel

The flows of sodium, potassium, and chloride under electrical and chemical gradients and of salt and water in the presence of osmotic pressure gradients are described by phenomenological equations based on the thermodynamics of irreversible processes. The aim was to give the simplest possible description, that is to postulate the least number of active transport processes and the least number of separate pathways across the intestine. On this basis, the results were consistent with the following picture of the intestine: Two channels exist across this tissue, one allowing only passive transport of ions and the other only active. In the passive channel, the predominant resistance to ion flow is friction with the water in the channel. The electroosmotic flow indicates that the passive channel is lined with negative fixed charged groups having a surface charge density of 3000 esu cm-2. The values of the ion-water frictional coefficients, and the relationship between ionic concentrations and flows indicate that the passive channel is extracellular. The active channel behaves as two membranes in series, the first membrane being semipermeable but allowing active transport of sodium, and the second membrane being similar to the passive channel. Friction with the ions in the second "membrane" is the predominant resistance to water flow.

scholarly journals Methods of Controlling Lift - off in Conductivity Invariance Phenomenon for Eddy Current Testing

2020 ◽  
Author(s):  
Zhongwen Jin ◽  
Yuwei Meng ◽  
Rongdong Yu ◽  
Ruochen Huang ◽  
Mingyang Lu ◽  
...  
Keyword(s):  
Linear Relationship ◽  
Eddy Current ◽  
Coating Thickness ◽  
Test Sample ◽  
Common Point ◽  
Coil Design ◽  
Current Testing ◽  
Lift Off ◽  
Two Parameters ◽  
The Relationship

<p>Previously, a conductivity invariance phenomena (CIP) has been discovered – at a certain lift-off, the inductance change of the sensor due to a test sample is immune to conductivity variations, i.e. the inductance – lift-off curve passes through a common point at a certain lift-off, termed as conductivity invariance lift-off. However, this conductivity invariance lift-off is fixed for a particular sensor setup, which is not convenient for various sample conditions. In this paper, we propose using two parameters in the coil design – the horizontal and vertical distances between the transmitter and the receiver to control the conductivity invariance lift-off. The relationship between these two parameters and the conductivity invariance lift-off is investigated by simulation and experiments and it has been found that there is an approximate linear relationship between these two parameters and the conductivity invariance lift-off. This is useful for applications where the measurements have restrictions on lift-off, e.g. uneven coating thickness which limits the range of the lift-off of probe during the measurements. Therefore, based on this relationship, it can be easier to adjust the configuration of the probe for a better inspection of the test samples.</p>

scholarly journals Relationship between body composition and selected motor components in 17-year-old adolescents residing in the city of Poznań in Poland

2018 ◽  
Vol 10 (1) ◽  
pp. 53-58
Author(s):  
Agata Glapa ◽  
Joanna Grzesiak ◽  
Makama Andries Monyeki
Keyword(s):  
Body Composition ◽  
Impedance Method ◽  
Physical Activity Interventions ◽  
Hand Grip ◽  
Adolescent Girls And Boys ◽  
Motor Component ◽  
Study Participants ◽  
The Relationship ◽  
The City ◽  
Shuttle Run

Summary Study aim: The objective of this study was to determine differences in body composition status and levels of selected motor components and assess the relationship between selected motor components and body composition in adolescent girls and boys. Material and methods: The study participants were 42 girls and 49 boys from a secondary school in the city of Poznan in Po­land who were participating in the “Active not only online” project. The percentage of body components was evaluated using a bio-impedance method. The modified Eurofit battery of tests was used to assess selected motor components. Results: The prevalence of overweight was higher (12.3%) in boys than girls (2.4%), and girls were more frequently under­weight (16.7%) than boys (6.1%). The results of the study show higher selected motor component levels in girls than in boys when compared to standardized population norms. BMI correlated positively with 20-m shuttle run (r = 0.45, p < 0.05) in girls and with sit and reach (r = 0.30, p < 0.05) in boys, with ‘hand grip’ strength both in girls (r = 0.35, p < 0.05) and boys (r = 0.29, p < 0.05), and was related to percentage of body fat in girls (r = 0.33, p < 0.05) and boys (r = 0.42, p > 0.05).Conclusions: The findings showed that sex and body composition are important factors influencing physical fitness in adoles­cents. We suggest that these factors be considered when designing physical activity interventions.

scholarly journals Pengaruh Profitabilitas Terhadap Nilai Perusahaan dengan Pengungkapan CSR sebagai variabel Moderasi (Perusahaan yang tergabung di JII dan Indeks SRI-KEHATI periode 2016-2018)

2020 ◽  
Vol 6 (11) ◽  
pp. 2331
Author(s):  
Niswatin Chasanah ◽  
Sylva Alif Rusmita
Keyword(s):  
Stock Prices ◽  
Stock Price ◽  
Stock Exchange ◽  
Test Sample ◽  
Independent Variables ◽  
Index Stock ◽  
Csr Disclosure ◽  
Corporate Social ◽  
Relationship Of ◽  
The Relationship

This study aims to determine and analyze the effect of profitability (ROA) on stock prices with corporate social responsibility (CSR) as a variable that moderates the two variables. The object of this research is companies incorporated in JII and SRI-KEHATI indexes that meet the test sample criteria during the period 2016 - 2018. This study uses a quantitative approach. Analysis of the data in this study used a moderation regression analysis (MRA). This study uses 20 samples for the JII index and 21 for the SRI-KEHATI index. Data obtained from the company's financial statements incorporated in JII and the SRI-KEHATI index for the period of 2016 - 2018 on the Indonesia Stock Exchange (IDX) website. The results showed that Return On Assets (ROA) had a significant effect on JII stock prices and SRI-KEHATI index stock prices. Furthermore, with CSR as a moderating variable showing the results of research with JII that is partially CSR disclosure shows a significant value which means CSR disclosure is able to moderate the relationship of ROA with JII stock prices. Overall (simultaneous) independent variables (ROA, CSR, ROA * CSR) significantly influence the stock price of JII. Furthermore, the results of research with the SRI-KEHATI index partially disclose CSR as a moderating variable showing a significant value. This means that CSR disclosure is not able to moderate the relationship of ROA with JII stock prices. while overall (simultaneous) independent variables (ROA, CSR, ROA * CSR) affect the stock price of the SRI-KEHATI index.Keywords: Profitability,StockPrice,ROA,CSR

An improvement to the ANN-enhanced flow rating method

2021 ◽  
Author(s):  
Bernhard Schmid
Keyword(s):  
Neural Network ◽  
Electrical Conductivity ◽  
Water Resources ◽  
Flow Rate ◽  
Major Ions ◽  
Rate Of Change ◽  
Data Set ◽  
Input Variables ◽  
Relationship Of ◽  
The Relationship

&lt;p&gt;The work reported here builds upon a previous pilot study by the author on ANN-enhanced flow rating (Schmid, 2020), which explored the use of electrical conductivity (EC) in addition to stage to obtain &amp;#8216;better&amp;#8217;, i.e. more accurate and robust, estimates of streamflow. The inclusion of EC has an advantage, when the relationship of EC versus flow rate is not chemostatic in character. In the majority of cases, EC is, indeed, not chemostatic, but tends to decrease with increasing discharge (so-called dilution behaviour), as reported by e.g. Moatar et al. (2017), Weijs et al. (2013) and Tunqui Neira et al.(2020). This is also in line with this author&amp;#8217;s experience.&lt;/p&gt;&lt;p&gt;The research presented here takes the neural network based approach one major step further and incorporates the temporal rate of change in stage and the direction of change in EC among the input variables (which, thus, comprise stage, EC, change in stage and direction of change in EC). Consequently, there are now 4 input variables in total employed as predictors of flow rate. Information on the temporal changes in both flow rate and EC helps the Artificial Neural Network (ANN) characterize hysteretic behaviour, with EC assuming different values for falling and rising flow rate, respectively, as described, for instance, by Singley et al. (2017).&lt;/p&gt;&lt;p&gt;The ANN employed is of the Multilayer Perceptron (MLP) type, with stage, EC, change in stage and direction of change in EC of the M&amp;#246;dling data set (Schmid, 2020) as input variables. Summarising the stream characteristics, the M&amp;#246;dling brook can be described as a small Austrian stream with a catchment of fairly mixed composition (forests, agricultural and urbanized areas). The relationship of EC versus flow reflects dilution behaviour. Neural network configuration 4-5-1 (the 4 input variables mentioned above, 5 hidden nodes and discharge as the single output) with learning rate 0.05 and momentum 0.15 was found to perform best, with testing average RMSE (root mean square error) of the scaled output after 100,000 epochs amounting to 0.0138 as compared to 0.0216 for the (best performing) 2-5-1 MLP with stage and EC as inputs only. &amp;#160;&amp;#160;&amp;#160;&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;References&lt;/p&gt;&lt;p&gt;Moatar, F., Abbott, B.W., Minaudo, C., Curie, F. and Pinay, G.: Elemental properties, hydrology, and biology interact to shape concentration-discharge curves for carbon, nutrients, sediment and major ions. Water Resources Res., 53, 1270-1287, 2017.&lt;/p&gt;&lt;p&gt;Schmid, B.H.: Enhanced flow rating using neural networks with water stage and electrical conductivity as predictors. EGU2020-1804, EGU General Assembly 2020.&lt;/p&gt;&lt;p&gt;Singley, J.G., Wlostowski, A.N., Bergstrom, A.J., Sokol, E.R., Torrens, C.L., Jaros, C., Wilson, C.,E., Hendrickson, P.J. and Gooseff, M.N.: Characterizing hyporheic exchange processes using high-frequency electrical conductivity-discharge relationships on subhourly to interannual timescales. Water Resources Res. 53, 4124-4141, 2017.&lt;/p&gt;&lt;p&gt;Tunqui Neira, J.M., Andr&amp;#233;assian, V., Tallec, G. and Mouchel, J.-M.: A two-sided affine power scaling relationship to represent the concentration-discharge relationship. Hydrol. Earth Syst. Sci. 24, 1823-1830, 2020.&lt;/p&gt;&lt;p&gt;Weijs, S.V., Mutzner, R. and Parlange, M.B.: Could electrical conductivity replace water level in rating curves for alpine streams? Water Resources Research 49, 343-351, 2013.&lt;/p&gt;

Effects of Respiration and Gravity on Infradiaphragmatic Venous Flow in Normal and Fontan Patients

Circulation ◽  
2000 ◽  
Vol 102 (suppl_3) ◽  
Author(s):  
Tain-Yen Hsia ◽  
Sachin Khambadkone ◽  
Andrew N. Redington ◽  
Francesco Migliavacca ◽  
John E. Deanfield ◽  
...  
Keyword(s):  
Flow Rate ◽  
Rate Ratio ◽  
Venous Return ◽  
Fontan Circulation ◽  
Flow Rate Ratio ◽  
Venous Flow ◽  
Beneficial Effects ◽  
In Series ◽  
Expiratory Flow ◽  
Fontan Patients

Background —In the Fontan circulation, pulmonary and systemic vascular resistances are in series. The implications of this unique arrangement on infradiaphragmatic venous physiology are poorly understood. Methods and Results —We studied the effects of respiration and gravity on infradiaphragmatic venous flows in 20 normal healthy volunteers (control) and 48 Fontan patients (atriopulmonary connection [APC] n=15, total cavopulmonary connection [TCPC] n=30). Hepatic venous (HV), subhepatic inferior vena caval (IVC), and portal venous (PV) flow rates were measured with Doppler ultrasonography during inspiration and expiration in both the supine and upright positions. The inspiratory-to-expiratory flow rate ratio was calculated to reflect the effect of respiration, and the supine-to-upright flow rate ratio was calculated to assess the effect of gravity. HV flow depended heavily on inspiration in TCPC compared with both control and APC subjects (inspiratory-to-expiratory flow rate ratio 3.4, 1.7, and 1.6, respectively; P <0.0001). Normal PV flow was higher in expiration, but this effect was lost in TCPC and APC patients (inspiratory-to-expiratory flow rate ratio 0.8, 1.0, and 1.1, respectively; P =0.01). The respiratory influence on IVC flow was the same in all groups. Gravity decreased HV flow more in APC than in TCPC patients (supine-to-upright flow rate ratio 3.2 versus 2.1, respectively; P <0.04) but reduced PV flow equally in all groups. Conclusions —Gravity and respiration have important influences on infradiaphragmatic venous return in Fontan patients. Although gravity exerts a significant detrimental effect on lower body venous return, which is more marked in APC than in TCPC patients, the beneficial effects of respiration in TCPC patients are mediated primarily by an increase in HV flow. These effects may have important short- and long-term implications for the hemodynamics of the Fontan circulation.

Interaction between CO2 concentration and flow rate on peripheral airway resistance

1991 ◽  
Vol 70 (6) ◽  
pp. 2514-2521 ◽  
Author(s):  
A. Kaise ◽  
A. N. Freed ◽  
W. Mitzner
Keyword(s):  
Flow Rate ◽  
Airway Resistance ◽  
Co2 Concentration ◽  
Low Flow ◽  
Flow Rates ◽  
Peripheral Airway ◽  
Residual Capacity ◽  
Local Ventilation ◽  
End Tidal ◽  
The Relationship

In the present study, we investigated the interaction between CO2 concentration and rate of delivered flow on peripheral airway resistance (Rp) in the intact canine lung. Dogs were anesthetized, intubated, paralyzed, and mechanically ventilated with room air to maintain end-tidal CO2 between 4.8 and 5.2%. Using a wedged bronchoscope technique, we measured Rp at functional residual capacity. The relationship between CO2 concentration and Rp was measured at flow rates of 100 and 400 ml/min with 5, 3, 2, 1, and 0% CO2 in air. Measurements were made at the end of a 3-min exposure to each gas. At low flow rates (100 ml/min) responses to hypocapnia were small, whereas at high flow rates (400 ml/min) responses were large. The PC50 (defined as the CO2 concentration required to produce a 50% increase in Rp above baseline Rp established on 5% CO2) at 400 ml/min (1.73%) was significantly larger than that at 100 ml/min (0.38%). We also directly measured the relationship between Rp and flow rate with 5% CO2 (normocapnia) or 1% CO2 (hypocapnia) delivered into the wedged segment. Increases in normocapnic flow caused small but significant decreases in Rp. In contrast, increases in hypocapnic flow from 100 to 400 ml/min caused a 108% increase in Rp. Thus the response to hypocapnia is augmented by increasing flow rate. This interaction can be explained by a simple model that considers the effect of local ventilation-perfusion ratio and gas mixing on the local CO2 concentration at the site of peripheral airway contraction.

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