Relation between outer and luminal diameter in cannulated arteries

1999 ◽  
Vol 277 (5) ◽  
pp. H1745-H1753 ◽  
Author(s):  
Gilles Faury ◽  
Gail M. Maher ◽  
Dean Y. Li ◽  
Mark T. Keating ◽  
Robert P. Mecham ◽  
...  
Keyword(s):  
Accurate Determination ◽  
Experimental Conditions ◽  
Cross Sectional ◽  
Luminal Diameter ◽  
Fluorescent Marker ◽  
Wide Range ◽  
Before And After ◽  
Single Determination ◽  
Knockout Animals

Resistance in blood vessels is directly related to the inner (luminal) diameter (ID). However, ID can be difficult to measure during physiological experiments because of poor transillumination of thick-walled or tightly constricted vessels. We investigated whether the wall cross-sectional area (WCSA) in cannulated arteries is nearly constant, allowing IDs to be calculated from outer diameters (OD) using a single determination of WCSA. With the use of image analysis, OD and ID were directly measured using either transillumination or a fluorescent marker in the lumen. IDs from a variety of vessel types were calculated from WCSA at several reference pressures. Calculated IDs at all of the reference WCSA were within 5% (mean <1%) of the corresponding measured IDs in all vessel types studied, including vessels from heterozygote elastin knockout animals. This was true over a wide range of transmural pressures, during treatment with agonists, and before and after treatment with KCN. In conclusion, WCSA remains virtually constant in cannulated vessels, allowing accurate determination of ID from OD measurement under a variety of experimental conditions.

Improved Procedure for Determining Water Activity in a High Range

1986 ◽  
Vol 69 (6) ◽  
pp. 952-956
Author(s):  
Walter D Flom ◽  
Nobumasa Tanaka ◽  
Susan K Kovats ◽  
Lynda M Finn
Keyword(s):  
Water Activity ◽  
Calibration Curve ◽  
Accurate Determination ◽  
Calibration Procedure ◽  
Calibration Scheme ◽  
Before And After ◽  
Single Determination ◽  
Precision And Accuracy ◽  
High Range

Abstract A procedure for accurate determination of water activity (aw) in a high range (aw between 0.920 and 0.970) using a Beckman Hygroline apparatus was devised because the prescribed calibration procedure was inadequate. This new procedure uses NaCl solutions as standards and the aw values for NaCl solutions reported by Robinson as the reference scale. A quadratic calibration curve: Recorder reading = b0 + b1aw + b2aw2 was established for each sensor. A 3-point calibration scheme, taking measurements of 0.9m (molal), 1.6m, and 2.4m NaCl solutions, was used before and after a series of aw measurements of samples to estimate b0 and verify the constancy of shape of the calibration curve. The equation was solved for aw to convert each recorder reading to an aw value on Robinson’s scale. This procedure yielded precision and accuracy levels for a single determination of 0.0009 and 0.0013 aw unit, respectively. Accuracy of 0.0009 aw unit was obtained by averaging 2 determinations on different sensors.

scholarly journals Dietary preferences and traditional practices according to the desired gender of the baby among pregnant women in South Eastern Turkey

2021 ◽  
Vol 8 (3) ◽  
pp. 1091
Author(s):  
Semra Akkoz Cevik ◽  
Emine Karacan ◽  
Aysegul Kılıçlı
Keyword(s):  
Pregnant Women ◽  
Large Family ◽  
Cross Sectional Study ◽  
Family Type ◽  
Traditional Practices ◽  
Traditional Practice ◽  
Cross Sectional ◽  
Dietary Preferences ◽  
Before And After

Background: Superstition and traditional practices regarding pregnancy exist in various cultures around the world and are passed down from generation to generation. As a result of the literature review, it was observed that there weren't prospective and cross-sectional studies involving traditional practices and dietary preferences of pregnant women before and after determining the gender according to the gender of the baby they want. The purpose of this study was to determine dietary preferences, superstitions and traditional practices before and after determining the gender of the baby according to the desired gender of the baby among pregnant women.Methods: The research was a descriptive cross-sectional study and adopted the pretest-posttest research design. As the data collection tool, both investigators-designed questionnaire forms and the non-functional beliefs and practices scale (NFBPS) related to pregnancy to the same pregnant women were applied before and after the determination of baby gender in the first and second trimesters respectively.Results: The study found that 85% of the pregnant women thought that dietary preferences during pregnancy have an impact on the gender of the true baby. The results showed that superstitions and traditional practices were known and practiced by pregnant women at a young age, uneducated, living in the province and having a large family type (p<0.05).Conclusions: Health professionals, should pay attention to less educated, younger pregnant women to reinforce positive cultural health practices, discourage to them from using harmful ones superstition and traditional practice by providing non-critical scientific explanations. 

Factors affecting constancy of acetate concentration and correct determination of methanogenic activity in pH-stat experiments

2003 ◽  
Vol 48 (6) ◽  
pp. 111-118
Author(s):  
M. Mösche ◽  
U. Meyer
Keyword(s):  
Accurate Determination ◽  
Original Method ◽  
Experimental Conditions ◽  
Methanogenic Activity ◽  
Factors Affecting ◽  
Acetate Concentration ◽  
Correct Determination ◽  
Ph Stat ◽  
The Stability

The determination of methanogenic activity with a pH-stat titration bioassay is evaluated utilising a mathematical model of this system. For given kinetic parameters and experimental conditions the model calculates the development of titrant flow and acetate concentration during experiments. Simulations of experiments under various conditions are compared. They show that the original method inherently causes a strong drift of acetate concentration during the experiments and a misestimation of methanogenic activity. As a solution to these disadvantages the addition of sodium hydroxide to the titrant and a careful control of pH during flushing the reactor with gas prior to the experiment are recommended. In this way a better constancy of acetate concentration and a more accurate determination of methanogenic activity should be achievable. The accuracy of this method is limited by the stability of pH-electrode calibration parameters.

scholarly journals Determining Girard Form Class in Central Hardwoods

1997 ◽  
Vol 14 (4) ◽  
pp. 202-206 ◽  
Author(s):  
John C. Rennie ◽  
Jack D. Leake
Keyword(s):  
Direct Measurement ◽  
Accurate Determination ◽  
Tree Form ◽  
Form Class ◽  
Wide Range ◽  
Close Proximity ◽  
Wedge Prism ◽  
The Cost ◽  
Volume Estimates

Abstract Girard form class is widely used to describe tree form. Tree volume estimates change about 3% per unit change of Girard form class (Mesavage and Girard 1946). Hardwoods growing in close proximity have been observed to have a wide range in Girard form class. Accurate determination of Girard form class can therefore be important in getting accurate estimates of hardwood timber volume. However, the cost of estimating Girard form class for every tree being measured in the stand would be prohibitively expensive. Thus, estimation of average Girard form class for a stand is considered here. Three instruments used to estimate Girard form class—a Wheeler pentaprism optical caliper, a wedge prism, and a Spiegel relaskop—were compared to direct measurement. Number of sample trees to achieve desired half-widths of the confidence interval of ±1 and ±1 1/2 units of Girard form class was calculated for each method. Direct measurement requires the fewest trees to achieve the desired results. However, it requires considerably more time per tree than any of the instruments tested. The Wheeler pentaprism requires only a few more trees than direct measurement, and considerably fewer trees than either the wedge prism or the Spiegel relaskop. Use of all three instruments is hindered when understory vegetation obscures the top of the first log. North. J. Appl. For. 14(4):202-206.

The Influence of the Cell Geometry on the Signal Shape in Electron Drift Velocity Measurements

1986 ◽  
Vol 41 (7) ◽  
pp. 912-920 ◽  
Author(s):  
A. F. Borghesani ◽  
L. Bruschi ◽  
M. Santini ◽  
G. Torzo
Keyword(s):  
Edge Effects ◽  
Accurate Determination ◽  
Finite Size ◽  
High Mobility ◽  
Drift Chamber ◽  
Cell Geometry ◽  
Experimental Conditions ◽  
Drift Cell ◽  
Cell Dimensions

An accurate determination of the “time-of-flight” in swarm experiments with a parallel plate drift chamber requires that the time evolution of the charge induced on the collector is linear. This is obtained in very large chambers where the edge effects can be neglected. However, the experimental conditions of high-mobility carriers and highly pressurized gases impose some constraints on the acceptable drift cell dimensions. We have numerically calculated the effects of the finite size of the collector by exploiting the methods of the images. The numerical results have been experimentally checked using a suitable drift cell of variable geometry. As a result, a quantitative limit on the ratio between the collector radius and the drift distance has been established in order to design drift cells for which the edge effects can be neglected. P.A.C.S. numbers: 2940. 4110 D, 3480 B

Collaborative Study of Maleic Hydrazide Residue Analysis

1965 ◽  
Vol 48 (4) ◽  
pp. 744-748
Author(s):  
J R Lane
Keyword(s):  
Maleic Hydrazide ◽  
Residue Analysis ◽  
Collaborative Study ◽  
French Fries ◽  
Food Crops ◽  
Good Reproducibility ◽  
Processed Food ◽  
Wide Range ◽  
Single Determination

Abstract The recoveries obtained from raw and processed food crops fortified with 10 μg or more of maleic hydrazide per analytical sample demonstrate that a wide range of concentrations of maleic hydrazide residues can be accurately determined. The test shows good reproducibility and agreement of data, considering the additional possible error of a blending at point of origin and reblending upon receipt by the collaborator, the lack of refrigeration, and the use of a single determination of the unknowns. The crops used included cranberries, onions, peaches, tobacco dust, and potatoes (whole, dehydrated mashed, frozen french fries, and potato chips). The average recoveries on these crops, fortified with 1.3–85 ppm, ranged from 70 to 92%.

scholarly journals The EFSA Health Claim on Olive Oil Polyphenols: Acid Hydrolysis Validation and Total Hydroxytyrosol and Tyrosol Determination in Italian Virgin Olive Oils

Molecules ◽  
2019 ◽  
Vol 24 (11) ◽  
pp. 2179 ◽  
Author(s):  
Maria Bellumori ◽  
Lorenzo Cecchi ◽  
Marzia Innocenti ◽  
Maria Lisa Clodoveo ◽  
Filomena Corbo ◽  
...  
Keyword(s):  
Olive Oil ◽  
Accurate Determination ◽  
Virgin Olive Oil ◽  
Extra Virgin Olive Oil ◽  
Health Claims ◽  
Official Method ◽  
Virgin Olive Oils ◽  
Corrective Factor ◽  
Before And After

The health claims of olive oil represent an important marketing lever in raising the willingness to pay for a product, but world producers of extra virgin olive oil (EVOO) do not take advantage of it because there are still obstacles to their use. Among these, one issue is the lack of an official method for determination of all free and linked forms derived from secoiridoidic structures of hydroxytyrosol and tyrosol. In this study, different acidic hydrolytic procedures for analyzing the linked forms were tested. The best method was validated and then applied to more than 100 EVOOs. The content of oleuropein and ligstroside derivatives in EVOOs was indirectly evaluated comparing the amount of phenols before and after hydrolysis. After acidic hydrolysis, a high content of total tyrosol was found in most of the EVOOs. The use of a suitable corrective factor for the evaluation of hydroxytyrosol allows an accurate determination only using pure tyrosol as a standard. Further knowledge on the concentration of total hydroxytyrosol will assist in forecasting the resistance of oils against aging, its antioxidant potential and to better control its quality over time.

scholarly journals The upper limits of the continuous β-ray spectra of thorium C and C″

1934 ◽  
Vol 147 (862) ◽  
pp. 572-582 ◽  
Keyword(s):  
Accurate Determination ◽  
Simple Relation ◽  
Maximum Energy ◽  
Energy Limit ◽  
Expansion Chamber ◽  
End Point ◽  
Upper Limits ◽  
Wide Range ◽  
Magnetic Analysis

It is well known that the disintegration electrons from a radioactive body are distributed over a wide range of velocities, and that a characteristic feature of this distribution is that there is an upper energy limit above which no electrons are emitted. The accurate determination of these upper limits and the corresponding maximum energy of the β-rays has become of much importance in connection with special theories which have been advanced to explain the nature of the β-ray disintegration. Numerous experiments have been done to find these upper limits or end points. Most of the existing data are based on range measurements in which the energy of the fastest β-rays from a source is deduced from their range. The chief advantage of the method is that it can be carried out with weak or rapidly decaying sources; the great disadvantage is that owing to the scattering suffered by the β-particles, the range found by experiment is an indefinite quantity and has no simple relation to the maximum energy of the β-particles. Because of this fact range methods, while frequently giving results in general agreement with magnetic analysis, are not capable of leading to accurate results for the upper limits. There remain two other methods of analysis, the magnetic spectrograph and the expansion chamber. The latter as used by Terroux and Alexander gives a higher upper limit than other methods. For radium E Terroux reported a tail extending to 3,000,000 volts, while other methods give an end point at about 1,070,000 volts. Champion, in repeating Terroux’s experiments, emphasized the precautions that must be taken in interpreting the experimental material. To eliminate the effect of scattering he was forced to adopt a criterion that a particle would be counted only if it had an undisturbed track greater than a certain length. The cloud-chamber method, while applicable to very weak sources, must be used with great care, and cannot give an accurate value of the end point without taking a very large number of photographs.

scholarly journals CREDIT CAPACITY ASSESSMENT OF COMMERCIAL BANK BORROWER

2019 ◽  
pp. 93-100
Author(s):  
A. Bondarenko ◽  
M. Moiseienko ◽  
V. Gordienko ◽  
O. Dutchenko
Keyword(s):  
Credit Risk ◽  
Accurate Determination ◽  
Integral Model ◽  
Risk Indicator ◽  
Probability Of Default ◽  
Financial Condition ◽  
Wide Range ◽  
Banking Institution ◽  
High Level

The purpose of the article is to study the essence of solvency of the enterprise, to determine the approaches to assessment and analysis of solvency. Since the assessment of the borrower's solvency is the key to the successful functioning not only of the financial and credit institution, but also of the enterprise itself, so in the conditions of formation and development of market relations lenders need to have an accurate idea of the borrower's solvency. Relevance of the research topic is explained by the fact that today the solvency of the enterprise requires a thorough and comprehensive research in terms of the solvency of enterprises and the development of a scientific justification for a common algorithm that borrowers can use to calculate their credit obligations. Today, there is no single algorithm for determining a borrower's solvency. Each banking institution uses its own methodology, which, in its opinion, is the most effective and takes into account a wide range of financial indicators. According to the valuation specificity for the assessment of legal entities regulated by the NBU, determining the borrower's solvency involves analyzing its financial and economic characteristics Requirements of the Regulations on the determination of the size of credit risk by the banks of Ukraine established the calculation of the credit risk indicator, which provides for the definition of the integral indicator, calculation of the borrower's financial class and the probability of default. Within the limits of the given research the complex estimation of Technologia JSC solvency has been carried out, by results of which the quantitative indicators received as a result of construction of the integral model, are included into the range of values corresponding to the second class of the borrower. Calculation of the overall qualitative indicator confirmed the high level of solvency of the studied enterprise, with a minimum probability of default. In order to improve the quality of the solvency assessment of the borrower we propose, in further studies, to consider the competitiveness of the enterprise as a factor of more accurate determination of its financial condition and solvency. Keywords: solvency, borrower, financial standing, financial factors.

Accurate Measurement on Cross Sectional Area of Single Filaments Using a Desktop SEM

2015 ◽  
Vol 1083 ◽  
pp. 111-117
Author(s):  
Xi Ying Yang ◽  
Ou Yang Ting ◽  
You Qing Fei
Keyword(s):  
Accurate Determination ◽  
Cross Sectional Area ◽  
Morphological Observation ◽  
Sectional Area ◽  
Cross Sectional ◽  
Fiber Properties ◽  
Measurement Results ◽  
Fiber Sample ◽  
Key Parameter

Cross sectional area of single filaments, a key parameter to characterize fiber properties, was experimentally studied using a desktop scanning electron microscope. Three different methods are employed based on the pixel area, averaged diameter and single diameter measurements, respectively. Results have shown that all three methods can achieve accurate measurement results once the axis of fiber sample is kept parallel to the electron beam. Significant errors are generated for the fiber samples with their axis tilted, which may frequently occur as a sample prepared. For circular fibers, a single diameter measured from tilted fibers is sufficient to determine their cross sectional area at high precision with COV values below 1.6%. By selecting an appropriate method, a desktop SEM can serve as a convenient and powerful tool for accurate determination of cross sectional area as well as morphological observation.

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