scholarly journals Filling of Irregular Channels with Round Cross-Section: Modeling Aspects to Study the Properties of Porous Materials

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1901 ◽  
Author(s):  
Yamel Ungson ◽  
Larysa Burtseva ◽  
Edwin Garcia-Curiel ◽  
Benjamin Valdez Salas ◽  
Brenda Flores-Rios ◽  
...  
Keyword(s):  
Cross Section ◽  
Circular Cross Section ◽  
Packing Fraction ◽  
Close Packing ◽  
Porous Structures ◽  
Round Cross Section ◽  
Packing Factor ◽  
First Approximation ◽  
Maximum Packing Fraction ◽  
Round Cross

The filling of channels in porous media with particles of a material can be interpreted in a first approximation as a packing of spheres in cylindrical recipients. Numerous studies on micro- and nanoscopic scales show that they are, as a rule, not ideal cylinders. In this paper, the channels, which have an irregular shape and a circular cross-section, as well as the packing algorithms are investigated. Five patterns of channel shapes are detected to represent any irregular porous structures. A novel heuristic packing algorithm for monosized spheres and different irregularities is proposed. It begins with an initial configuration based on an fcc unit cell and the subsequent densification of the obtained structure by shaking and gravity procedures. A verification of the algorithm was carried out for nine sinusoidal axisymmetric channels with different Dmin/Dmax ratio by MATLAB® simulations, reaching a packing fraction of at least 0.67 (for sphere diameters of 5%Dmin or less), superior to a random close packing density. The maximum packing fraction was 73.01% for a channel with a ratio of Dmin/Dmax = 0.1 and a sphere size of 5%Dmin. For sphere diameters of 50%Dmin or larger, it was possible to increase the packing factor after applying shaking and gravity movements.

An Iron Anthropoid Sword from Shouldham, Norfolk with Related Continental and British Weapons

1956 ◽  
Vol 21 ◽  
pp. 198-227 ◽  
Author(s):  
R. R. Clarke ◽  
C. F. C. Hawkes
Keyword(s):  
Cross Section ◽  
Kind Permission ◽  
Human Skeleton ◽  
Round Cross Section ◽  
Unequal Size ◽  
Arable Field ◽  
Medieval Church ◽  
The Reformation ◽  
Round Cross

An iron sword of anthropoid-hilted type (pl. XXIV, 1, 3) was found in 1944 at Shouldham in West Norfolk, some five miles east of the margin of the Fens, and since 1949 has been on loan to Norwich Castle Museum. It is here published by kind permission of the owner, Mr W. R. O. Woodward. The sword was discovered while gravel was being dug in an arable field about 200 feet south-east of the site of the medieval church of St. Margaret, which fell into ruins after the Reformation. The sword was found at a depth of 1 foot 6 inches lying across the chest of an extended human skeleton inside the boundary of the medieval churchyard, as graves of that period were found adjacent though they had not disturbed this pre-Christian inhumation. There is no indication either on the ground or on air-photographs that a barrow had formerly existed, and the burial is probably to be regarded as an isolated interment.The overall length of the sword, to the end of the branching arms, is now 21⅜ in. (54 cm.), but this has been slightly diminished by corrosion. The straight-edged blade is 16⅜ in. (44 cm.) long and the hilt measures 3¼ in. (8 cm.). At both ends of the hilt curving arms of round cross-section branch outwards to end in knobs, now of unequal size owing to differential rusting. The surface of the grip bears traces of transverse ribbing, perhaps imitating that found in bronze on other examples of the type.

scholarly journals Spatial Spectroscopy Approach for Detection of Internal Defect of Component without Zero-Position Sensors

2016 ◽  
Vol 2016 ◽  
pp. 1-5
Author(s):  
Qizhou Wu ◽  
Yong Jin ◽  
Zhaoba Wang ◽  
Zhaoqian Xiao
Keyword(s):  
Cross Section ◽  
Biological Tissues ◽  
Noninvasive Detection ◽  
Object Surface ◽  
Internal Defect ◽  
Round Cross Section ◽  
X Ray ◽  
Zero Position ◽  
Round Cross ◽  
Distance Signal

Conventional approach to detect the internal defect of a component needs sensors to mark the “zero” positions, which is time-consuming and lowers down the detecting efficiency. In this study, we proposed a novelty approach that uses spatial spectroscopy to detect internal defect of objects without zero-position sensors. Specifically, the spatial variation wave of distance between the detecting source and object surface is analyzed, from which a periodical cycle is determined with the correlative approaches. Additionally, a wavelet method is adopted to reduce the noise of the periodic distance signal. This approach is validated by the ultrasound detection of a component with round cross section and elliptical shape in axis. The experimental results demonstrate that this approach greatly saves the time spent on the judgment of a complete cycle and improves the detecting efficiency of internal defect in the component. The approach can be expanded to other physical methods for noninvasive detection of internal defect, such as optical spectroscopy or X-ray scanning, and it can be used for hybrid medium, such as biological tissues.

scholarly journals Pulsation parameters of new and used milking liners with round cross section

2021 ◽  
Vol 13 (3) ◽  
pp. 288-291
Author(s):  
G. Dineva ◽  
K. Peychev ◽  
D. Georgiev
Keyword(s):  
Service Life ◽  
Cross Section ◽  
Holstein Cattle ◽  
Frequency Range ◽  
Round Cross Section ◽  
Round Cross

Abstract. Milking machines equipped with new and used milking liners with a round cross section were studied. The used milking membranes were operated for 3 months on a farm for rearing 60 cows (Holstein cattle) with double milking per day. The experiment involved recording the standard pulsation phases “a”, “b”, “c” and “d” (in absolute units) in the frequency range from 1 Hz to 2.5 Hz, in a vacuum mode of 40 kPa and 50 kPa and at a pulsation ratio of 50/50%. It was found that the transients (phase “a” and phase “c”) are faster and the established phases (phase “b” and phase “d”) are longer in milking units equipped with used milking liners. The conclusions are related to the service life of the milking liners.

scholarly journals Correction: Ungson, Y. et al. Filling of Irregular Channels with Round Cross-Section: Modeling Aspects to Study the Properties of Porous Materials. Materials 2018, 11, 1901

Materials ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 818
Author(s):  
Yamel Ungson ◽  
Larysa Burtseva ◽  
Edwin Garcia-Curiel ◽  
Benjamin Valdez Salas ◽  
Brenda Flores-Rios ◽  
...  
Keyword(s):  
Porous Materials ◽  
Cross Section ◽  
Round Cross Section ◽  
Round Cross

The authors have found two errors in the paper published in Materials [...]

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