scholarly journals Estimation of Seams in Paraglider Wing

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Paulina Maślanka ◽  
Ryszard Korycki ◽  
Halina Szafrańska
Keyword(s):  
Pressure Difference ◽  
Relative Elongation ◽  
Test Results ◽  
Physical Strength ◽  
Covering Material ◽  
Mean Pressure ◽  
Maximal Pressure ◽  
Flight Parameters ◽  
The Mean

AbstractThe aim of the article is to analyze the seams connecting the covering textiles in paraglider wing and estimate their physical strength. The most extreme flight parameters (the angle of attack and velocity) in the numerical model of the wing allow the determination of the mean pressure inside the contour and the maximal difference between the pressures on the inner and the outer material surfaces. The preprocessing stage and numerical calculations in Ansys environment consider three different covering materials. The tool Porous Media is used to create the objects of a given value of air permeability. The estimated parameter of seam is the maximal pressure difference between both sides of the covering material, which that interacts with the test results. The quality index of the seam is defined by the maximal force to seam rupture and relative elongation during rupture. The obtained results indicate that the seams are resistant to the pressure difference caused by the most extreme flight parameters.

scholarly journals Quantitative nephelometric assay for determining myoglobin evaluated

1990 ◽  
Vol 36 (9) ◽  
pp. 1675-1678 ◽  
Author(s):  
J R Delanghe ◽  
J P Chapelle ◽  
S C Vanderschueren
Keyword(s):  
Reliable Method ◽  
High Dose ◽  
Rheumatoid Factors ◽  
Test Results ◽  
Multiple Forms ◽  
Hook Effect ◽  
Tissue Extracts ◽  
The Mean ◽  
Serum Myoglobin

Abstract A recently introduced automated nephelometric immunoassay involving shell/core particles for determination of myoglobin (Behringwerke) was evaluated with the BNA Nephelometer. Method precision was good: the intra-assay CV varied between 1.5% and 6.1%; with daily calibration, the interassay CV ranged between 1.5% and 7.5%. For usual sample dilutions, the assay response varied linearly with myoglobin concentrations up to 23.1 nmol/L. After automatic dilution by the instrument, concentrations up to 2310 nmol/L could be measured without high-dose "hook" effect. Further manual dilution allowed measurement of myoglobin concentrations up to 26,000 nmol/L. Calibration was stable for at least seven days. We detected no significant interferences from hemoglobin, haptoglobin, bilirubin, iodine-containing contrast media, and rheumatoid factors. Treating lipemic samples with Lipoclean (Behringwerke) decreased test results. Simultaneously drawn serum and plasma samples from the same subject showed no consistent differences in myoglobin concentrations. The mean reference myoglobin concentration was 1.380 (SD 0.82) nmol/L for men and 0.878 (SD 0.45) nmol/L for women. In patients with renal insufficiency, serum creatinine values were moderately related to serum myoglobin values (r = 0.465). Although a commercial radioimmunoassay (Byk-Sangtec) and the nephelometric assay intercorrelated well (r = 0.929), values obtained by nephelometry were significantly lower (P less than 0.05). By both assays, results for heart and skeletal muscle tissue extracts showed no correlation, a finding that suggests the existence of multiple forms of myoglobin in human tissues. We conclude that immunonephelometry is a rapid, practical, and reliable method for measuring myoglobin in serum.

One Step Closer towards a Reliable Tinnitus Pitch-Match Frequency Determination Using Repetitive Recursive Matching

2020 ◽  
Vol 25 (4) ◽  
pp. 190-199 ◽  
Author(s):  
Daniela Korth ◽  
Andreas Wollbrink ◽  
Robert Wunderlich ◽  
Daniela Ivansic ◽  
Orlando Guntinas-Lichius ◽  
...  
Keyword(s):  
Internal Consistency ◽  
Choice Test ◽  
Test Results ◽  
Outlier Identification ◽  
Excellent Internal Consistency ◽  
One Step ◽  
Matching Procedure ◽  
The Mean ◽  
Very High

Introduction: The determination of the tinnitus pitch-match (PM) frequency is not straightforward but an important audiological assessment recommended for clinical and research purposes. We evaluated repetitive recursive matching using an iPod-based matching procedure as a method to estimate a patient’s PM frequency without audiometric equipment. Methods: One hundred and seventeen patients with chronic tonal tinnitus (uni- and bilateral tinnitus) measured their tinnitus in 10 sessions using a self-administered automated iPod-based procedure comprising a recursive 2 interval forced-choice test. Results: Mean SD of the PM frequency of all participants across sessions was 0.41 octaves. The internal consistency measured by Cronbach’s α was very high (0.8–>0.95). As an example, 7 PMs obtained excellent internal consistency (α = 0.93). The exclusion of the first and/or second session led to more definite PMs with a decreased SD. Outliers were identified by PMs departing 2 SDs (i.e., 0.94 octaves) from the mean variability (n = 5). Conclusion: Repetitive recursive matching together with recommendations for the exclusion of initial and redundant sessions as well as outlier identification and treatment can enable a reliable estimation of the PM frequency.

scholarly journals Investigation of the unfused cross cylinder test as an alternative method for the determination of spherical distance refraction end points

2020 ◽  
Vol 79 (1) ◽  
Author(s):  
Nkalebetja T. Makgaba ◽  
Solani D. Mathebula
Keyword(s):  
Adult Population ◽  
Test Results ◽  
End Points ◽  
Room Illumination ◽  
End Point ◽  
Cylinder Test ◽  
Significant Difference ◽  
Young Adult Population ◽  
The Mean

Background: The duochrome test is commonly used to refine the final sphere in refraction at different stages of a subjective refraction. The unfused cross cylinder test is mainly used to determine the near reading addition with a combination of astigmatic lenses.Aim: To investigate if the unfused cross cylinder test can be adapted for distance in finding the spherical end point for distance prescription.Setting: The study was conducted at an Optometry Clinic, University of Limpopo, South Africa.Methods: Fifty-one non-presbyopic subjects aged between 18 and 25 years were examined. The duochrome and unfused cross cylinder examinations were performed monocularly under normal (bright) and dim room illumination.Results: There was no significant difference in the spherical end point determined with either the duochrome or unfused cross cylinder tests (p ≥ 0.05). The mean spherical end points as determined with the duochrome test were −0.09 ± 0.39 diopre sphere (DS) (range: −0.20 to 0.12 dioptres [D]) in bright room illumination and −0.05 ± 0.38 DS (range: −0.16 D to 0.05 D) in dim illumination. The mean spherical end points for the unfused cross cylinder tests were −0.29 ± 0.39 DS (range: −0.18 D to 0.40 D) and −0.32 ± 0.43 DS (range: –0.44 D to –0.19 D) in room dim illuminations, respectively.Conclusion: The unfused cross cylinder test results as performed in this study may provide an accurate measurement of the spherical end point in a young adult population. We recommend the unfused cross cylinder test to be used in normal (bright) room illumination as an alternative to the duochrome test in the determination of distance refractive error.

scholarly journals Anthropogenetic variability in the groups of homo- and heterosexually oriented individuals

Genetika ◽  
2015 ◽  
Vol 47 (2) ◽  
pp. 765-776
Author(s):  
Suzana Cvjeticanin
Keyword(s):  
Genetic Variability ◽  
Population Genetic ◽  
Control Group ◽  
Population Genetic Study ◽  
Test Results ◽  
Mean Values ◽  
Significant Difference ◽  
The Mean ◽  
Distribution Type

This population-genetic study compares morphophysiological and genetic variability in a group of homosexually oriented individuals from Serbia (N=96) with control group of heterosexual individuals (N=96) using a test of determination of homozygously recessive characteristics in humans (HRC-test). Results of our study revealed a statistically significant difference in the mean values of genetic homozygosity (control group 5.0+0.2 ; homosexuals 3.4 +0.1 HRCs, out of 20 observed characteristics) the differences in the distribution type, as well as in the variances of presence of specific combinations of such traits. These results suggest a complex polygenic difference between two observed systems. There is no difference in the degree of genetic homozygosity between the genders in each tested group of individuals. However, both homosexually oriented females and males have significantly lower mean values of HRCs compared to female and male heterosexuals.

Patterns of lactate dehydrogenase isoenzymes 1 and 2 in serum of patients performing an exercise test.

1989 ◽  
Vol 35 (2) ◽  
pp. 301-303 ◽  
Author(s):  
Z Rotenberg ◽  
I Weinberger ◽  
A Sagie ◽  
J Fuchs ◽  
E Davidson ◽  
...  
Keyword(s):  
Lactate Dehydrogenase ◽  
Exercise Test ◽  
Test Results ◽  
Normal Range ◽  
St Depression ◽  
Negative Results ◽  
Ratio Determination ◽  
The Mean ◽  
Lactate Dehydrogenase Isoenzymes

Abstract Values for total lactate dehydrogenase (LD, EC 1.1.1.27) activity and LD isoenzymes were determined in serum from 56 patients and 40 healthy subjects before and 24, 48, and 72 h after they performed an exercise test. The mean (for all four times) total LD activity concentration and proportion of LD-2 were within the normal range for all 96 subjects. Mean LD-1 values for serum, although within the normal range in all subjects, were significantly higher in patients with positive exercise test results than in subjects with negative results: 75 (SD 12) U/L in 35 patients with ST depression greater than 2 mm; 63 (SD 14) U/L in 16 patients with ST depression of 1-2 mm; 43 (SD 11) U/L in subjects with negative test results, by 48 h after the test. The LD 1:2 ratio was also markedly higher in the group of patients with positive test exercise results, especially in those with ST depression greater than 2 mm (1.02, SD 0.06), compared with those subjects with negative results (0.60, SD 0.04). A similar trend was also found 24 and 72 h after the exercise test. We conclude that exercise-myocardial ischemia may lead to an increased LD 1:2 ratio in serum, and demonstrate a correlation between the degree of ischemia and the LD 1:2 ratio. Determination of the LD 1:2 ratio, even in the presence of normal total LD activity, may assist in the clinical evaluation of patients performing an exercise test.

Determination of Resistance to Abrasive Wear. X. Investigation of the Durability of a Bonded Abrasive Wheel on the Du Pont Machine

1949 ◽  
Vol 22 (1) ◽  
pp. 264-268 ◽  
Author(s):  
R. G. Newton ◽  
J. R. Scott
Keyword(s):  
Abrasive Wear ◽  
Test Results ◽  
Volume Loss ◽  
Abrasive Wheel ◽  
Abrasive Particles ◽  
Significant Difference ◽  
Statistical Planning ◽  
The Mean ◽  
Test Result

Abstract The results reported here entirely confirm those of Lambourn, who found that marked deterioration occurred with all the types of abrasive wheel which he used. In the present investigation on a bonded wheel, it was concluded that the wheel was appreciably less abrasive after each period of. 50 hours' wear, while Lambourn concluded that one side of a wheel can be used for a period of two months when subjected to 40 hours of wear per week. Lambourn also concluded that the deterioration is caused by smoothing or disintegration of the abrasive particles and not by clogging with rubber dust, and points out that variation in abrasive wear can be compensated by daily tests on samples of a standard compound. He also states that a grain coarser than 24 should not be used, since the abrasion is too rapid. Since the standard emery papers vary among themselves, and the bonded abrasive wheel deteriorates when it is used, it is evident that attention should be paid to the statistical planning of these tests, so that these factors can be reduced or eliminated. The coefficient of variation of a test result, i.e., the mean of three 10-minute runs, each on duplicate specimens, (six individual readings) as normally measured, seems to be independent of the type of abrasive employed (emery papers or bonded disc) and the uncertainty of the result is about ±5 per cent when measured on the basis of volume loss per hour and about ±3.5 per cent when determined as the volume loss/H.P.-hr. Test results will therefore be required to differ by about 7 and about 5 per cent, respectively, for a significant difference to be demonstrated.

scholarly journals Sex and side determination of human hip bone by metric parameters of its posterior border

2013 ◽  
Vol 02 (01) ◽  
pp. 016-021
Author(s):  
Sarita R Margam ◽  
Megha A Doshi ◽  
Surekha D Jadhav ◽  
Raosaheb J Patil ◽  
Manoj P Ambali
Keyword(s):  
Sex Determination ◽  
Ischial Tuberosity ◽  
Test Results ◽  
Posterior Border ◽  
Bone Material ◽  
Significant Difference ◽  
The Mean ◽  
Two Parameters ◽  
Superior Border

Abstract Background: Identification of sex from skeletal remains is of medico-legal and anthropological importance for forensic experts, anthropologists and anatomists. Hip bone is considered as an ideal bone for sex determination as it provides the highest accuracy levels for sex determination. Aims: To determine the sex and side of the human hip bones by using different metric parameters of posterior border of hip bone. Material and methods: In present study, 200 (100 males and 100 females) dried adult human hip bones of known sex were collected. Two parameters were studied and statistically analysed by paired and unpaired 't' test. Results: In males, distance from the posterior superior iliac spine to the superior border of ischial tuberosity was the discriminant criteria to sex the hip bones while in females, it was distance between the posterior inferior iliac spine (PITS) to ischial tuberosity (IT). Statistically significant difference between the mean related to side were seen in both the variables. Conclusion: These two parameters can be used for sexual dimorphism as well as side determination of human hip bones or its fragments.

scholarly journals Consequences of intravascular lymphatic valve properties: a study of contraction timing in a multi-lymphangion model

2016 ◽  
Vol 310 (7) ◽  
pp. H847-H860 ◽  
Author(s):  
Christopher D. Bertram ◽  
Charlie Macaskill ◽  
Michael J. Davis ◽  
James E. Moore
Keyword(s):  
Pressure Difference ◽  
Refractory Period ◽  
Ex Vivo ◽  
Lymphatic Vessels ◽  
Lymphatic Valve ◽  
Mean Pressure ◽  
In Series ◽  
The Mean ◽  
A Chain ◽  
Lymphatic Pumping

The observed properties of valves in collecting lymphatic vessels include transmural pressure-dependent bias to the open state and hysteresis. The bias may reduce resistance to flow when the vessel is functioning as a conduit. However, lymphatic pumping implies a streamwise increase in mean pressure across each valve, suggesting that the bias is then potentially unhelpful. Lymph pumping by a model of several collecting lymphatic vessel segments (lymphangions) in series, which incorporated these properties, was investigated under conditions of adverse pressure difference while varying the refractory period between active muscular contractions and the inter-lymphangion contraction delay. It was found that many combinations of the timing parameters and the adverse pressure difference led to one or more intermediate valves remaining open instead of switching between open and closed states during repetitive contraction cycles. Cyclic valve switching was reliably indicated if the mean pressure in a lymphangion over a cycle was higher than that in the lymphangion upstream, but either lack of or very brief valve closure could cause mean pressure to be lower downstream. Widely separated combinations of refractory period and delay time were found to produce the greatest flow-rate for a given pressure difference. The efficiency of pumping was always maximized by a long refractory period and lymphangion contraction starting when the contraction of the lymphangion immediately upstream was peaking. By means of an ex vivo experiment, it was verified that intermediate valves in a chain of pumping lymphangions can remain open, while the lymphangions on either side of the open valve continue to execute contractions.

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