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1

Evaluating measurement accuracy and repeatability with a new device that records spatial knee movement

Tian Fei, Huang Qiuyue, Zheng Zhi, Li Ningwei, Zhu Ting, Dai Wei, Wang Shaobai

Acta of Bioengineering and Biomechanics

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2020

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Vol. 22, no. 3

55--67

EN

Purpose: A novel portable system has been used to evaluate spatial knee movement, but its accuracy and repeatability is not known. The aim of this study was to investigate the accuracy and repeatability of the measurement. Methods: Ten healthy participants were included, and the knee motion trajectory during walking were assessed. Six evaluations were conducted (three days by two raters) for each participant. The motion parameters at the key points and the range of motion were statistically analyzed. Intraclass correlation coefficients (ICC), standard error of the measurement (SEM), and the Bland–Altman method were used. Results: For intra-rater repeatability, 1) the ICC values range from 0.75 to 0.9 for rotations; and 0.64 to 0.96 for translations. Among the ICC values, 100% of rotations and 90% of translations were not less than 0.70; 2) among the SEM values, 100% of rotations were not more than 5°, while 73.3% of translations were less than 3 mm. For inter-rater repeatability, 1) the ICC values range from 0.68 to 0.99 for rotations; and 0.57 to 0.93 for translations. Among the ICC values, 95.6% of rotations and 82.2% of translations were not less than 0.70; 2) among the SEM values, 100% of rotations were not more than 5°, and 48.9% of translations were less than 3 mm. The Bland–Altman plots showed good agreement for intra- and inter-repeatability. Conclusions: The results indicated that the accuracy and repeatability of the measurement were acceptable, except for the inter-rater repeatability for translation. This may help researchers and physicians better interpret the measurement data.

2

Analiza zawodności ochrony odgromowej w ujęciu przestrzennym

Pacoń Radosław, Benesz Mariusz

Zeszyty Naukowe Wydziału Elektrotechniki i Automatyki Politechniki Gdańskiej

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2019

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Nr 68

41--44

PL

Możliwość identyfikacji narażeń napięciowych układów izolacyjnych znacząco wpływa na efektywność w koordynacji izolacji, co z kolei wpływa na zwiększenie niezawodności w przesyle i rozdziale energii elektrycznej. W artykule poruszono jeden z możliwych scenariuszy narażeń napięciowych w napowietrznych liniach elektroenergetycznych związany z zawodnością ochrony odgromowej. Ważne znaczenie w zachowaniu ochrony odgrywa ukształtowanie terenu, które może mieć pozytywny jak i negatywny wpływ na ochronę przed bezpośrednimi wyładowaniami atmosferycznymi. Rezultatem pracy jest określenie charakterystycznych wartości szczytowych prądu wyładowania atmosferycznego IUBmax, powyżej których ochrona odgromowa jest zachowana. Obliczenia przeprowadzono w ujęciu przestrzennym dla typowej konstrukcji wsporczej serii B2 typu przelotowego i czterech przypadków ukształtowania powierzchni terenu.

EN

The ability to identify of overvoltage in insulation systems significantly affects the efficiency in the coordination of insulation, which increases the reliability of electrical power transmission and distribution systems. The purpose of the paper is to present the problems related to one of the possible scenarios of overvoltages caused by atmospheric discharge, which is shielding failure. In this scenario, despite the ground wires used, it is possible to direct hiss into the phase conductor by atmospheric discharge. Lightning protection conditions may be additionally affected by the lay of the land, which was checked in this paper. The result of the work is the determination of characteristic peak values of the lightning current IBUmax, above which lightning protection is maintained. Calculations were carried out for a typical B2 tower profile with different height and four cases taking into account different terrain.

3

Effect of slip condition on vertical channel flow in the presence of radiation

Guria M.

International Journal of Applied Mechanics and Engineering

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2016

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Vol. 21, no. 2

341--358

EN

An analysis is made on the three dimensional flow of a viscous incompressible fluid through a vertical channel in the presence of radiation in slip flow regime. The right plate is subjected to an uniform injection and the left plate to a periodic suction velocity distribution. The velocity and temperature fields have been derived using the perturbation technique. It is found that the velocity decreases with the increase of the slip parameter. It is also found that the velocity decreases with the increase of the radiation parameter but near the right plate it increases. For cooling of the plate, the velocity increases with the increase of the Grashoff number and decreases near the right plate but the reverse effect is observed for heating the plate.

4

Radiation effect on three dimensional vertical channel flow through porous medium

Guria M.

International Journal of Applied Mechanics and Engineering

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2015

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Vol. 20, no. 4

817--833

EN

The flow of a viscous incompressible fluid through a vertical channel in the presence of radiation immersed in a porous medium has been studied. Approximate solutions have been obtained for the velocity and temperature fields, shear stresses and rate of heat transfer using the perturbation technique. It is found that the primary velocity decreases with an increase in the radiation parameter as well as the Prandtl number for cooling of the plate. It is also found that with an increase in the permeability parameter, the primary velocity increases for cooling of the plate. The magnitude of the secondary velocity decreases near the plate y = 0 and increases near the plate y = d with an increase in the permeability parameter. The temperature distribution decreases with an increase of the radiation parameter as wall as the Prandtl number for cooling of the plate. The shear stresses and the rate of heat transfer, which are of physical interest, are presented in the form of tables.

5

Manufacturing and Flat-wise Compression Performance of Modified 3D Integrated Sandwich Fabric Composites

Yu K, Cao H, Qian K, Li H

Fibres & Textiles in Eastern Europe

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2014

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Vol. 22, no. 3 (105)

98--102

EN

In this study, a novel manufacturing technique for three-dimensional integrated sandwich fabric with an ‘8’-shaped inside layer structure was developed. Furthermore a new integrated sandwich fabric with an ‘88’-shaped inside layer structure was designed in comparison with the ‘8’-shaped inside layer structure. The flatwise compression characteristics of the three-dimensional integrated sandwich fabric composites with different inside layer angles, inside layer heights and inside layer structures were investigated. The results showed that the inside layer structure of integrated sandwich fabric composites woven by the double rapier technique stand more uprightly than those woven by the traditional velvet weaving technique. What is more the corresponding flatwise compression performance was also greatly improved. Furthermore compared to ‘8’-shaped inside layer structure composites, ‘88’-shaped inside layer structure composites can not only retain the majority of pores but also greatly improve the flatwise compression performance of the composites.

PL

W pracy przedstawiono nową technikę wytwarzania przestrzennych zintegrowanych warstwowych tkanin o strukturze stosu w kształcie “8”. Następnie zaprojektowano nową warstwową tkaninę o strukturze stosu w kształcie „88” dla porównania ze strukturą „8”. Przebadano tkaniny warstwowe ze stosami o różnych kątach, wysokościach i strukturach. Wyniki wykazały, że struktura stosu zintegrowanej tkaniny warstwowej tkana techniką podwójnego rapieru jest bardziej prostopadła niż w przypadku tkania metodą tradycyjną. Niezależnie od tego wykazano, że tkaniny o stosie „88” nie tylko lepiej zachowują większość por, ale znacznie polepszają zachowanie się struktur podczas płaskiego ściskania.

6

Three-dimensional oscillating flow between two parallel plates through a porous medium

Guria M., Ghara N., Jana R. N.

International Journal of Applied Mechanics and Engineering

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2013

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Vol. 18, no. 4

1025--1037

EN

An unsteady Couette flow between two parallel plates when upper plates oscillates in its own plane and is subjected to a constant suction and the lower plate to a injection velocity distribution through the porous medium has been analyzed. The approximate solution has been obtained using perturbation technique. It is seen that the primary velocity increases whereas the secondary velocity decreases with an increase in permeability parameter. It is also found that the primary velocity increases with an increase in the Reynolds number as well as the suction parameter. The magnitude of the secondary velocity increases near the stationary plate but decreases near the oscillating plate with an increase in the Reynolds number. Whereas, it increases with an increase in the suction parameter.

7

Three dimensional MHD free convection flow and heat transfer through a vertical channel

Guria M., Ghara N., Jana R. N.

International Journal of Applied Mechanics and Engineering

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2010

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Vol. 15, no 4

1047-1063

EN

An analysis is made on the three dimensional MHD flow of a viscous incompressible fluid through a vertical channel in the presence of a uniform injection on the right plate and the left plate is subject to a periodic suction. The velocity and temperature fields are derived using the perturbation technique. It is observed that the primary velocity increases near the left plate and decreases near the right plate with an increase in the Reynolds number while it decreases with an increase in the magnetic parameter. It is seen that with an increase in the Prandtl number the primary velocity decreases whereas it increases with an increase in the Grashof number. It is seen that the magnitude of the secondary velocity increases in the range […] and thereafter decreases with an increase in the Reynolds number. It is also seen that the shear stress due to primary flow increases with an increase in either the Grashof number or Reynolds number but decreases with an increase in the Prandtl number. It is seen that the shear stress […] at the plate […] decreases with an increase in the magnetic parameter. Also, the magnitude of the shear stress due to cross flow increases with an increase in the Reynolds number. It is seen that the temperature at any point decreases with an increase in either the Prandtl number or Reynolds number. The rate of heat transfer in terms of the Nusselt number is also studied. Dimensional variables are indicated by dropping the asterisk and are defined in Eq.(2.8).

8

Radiation effect on three dimensional vertical channel flow

Guria M., Ghara N., Jana R. N.

International Journal of Applied Mechanics and Engineering

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2010

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Vol. 15, no 4

1065-1081

EN

An analysis is made of the three dimensional flow of viscous incompressible fluid through a vertical channel in the presence of a uniform injection on the right plate and a periodic suction velocity distribution on the left plate with radiation effect. The velocity and temperature fields are derived using the perturbation technique. It is found that the primary velocity decreases with an increase in the radiation parameter. It is seen that the shear stress due to primary flow increases with an increase in the Reynolds number but decreases with an increase in the radiation parameter. It is also seen that the temperature decreases with an increase in the radiation parameter. The rate of heat transfer in terms of the Nusselt number is also studied.

9

Three dimensionaI oscillating flow between two parallel plates with heat transfer

Guria M., Jana R. N.

International Journal of Applied Mechanics and Engineering

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2007

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Vol. 12, no 1

19-35

EN

The unsteady viscous incompressible Couette flow between two parallei plates when the upper plate oscillates in its own piane and is subjected to a constant suction whereas the lower plate is subjected to a suction velocity distribution has been theoretically analyzed. An approximate solution has been obtained using perturbation technique. It is found that the main flow velocity increases with an increase in the Reynolds number as well as suction parameter but it decreases with an increases in the frequency parameter. It is also shown that with an increase in the Reynolds number, the magnitude of the cross velocity increases near the stationary plate but decreases near the oscillating plate. On the other hand, it increases with an increase in the suction parameter. The heat transfer characteristic has also been studied by taking viscous dissipation into account. It is found that the temperature increases with an increase in the Reynolds number as well as the Prandtl number but it decreases with an increase in the frequency parameter.