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

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.

1956 ◽  
Vol 21 ◽  
pp. 198-227 ◽  
Author(s):  
R. R. Clarke ◽  
C. F. C. Hawkes

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.


2016 ◽  
Vol 2016 ◽  
pp. 1-5
Author(s):  
Qizhou Wu ◽  
Yong Jin ◽  
Zhaoba Wang ◽  
Zhaoqian Xiao

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.


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

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


Tribologia ◽  
2019 ◽  
Vol 286 (4) ◽  
pp. 95-103
Author(s):  
Wojciech SZCZYPIŃSKI-SALA ◽  
Agnieszka TOMALA ◽  
Janusz LUBAS

The issues associated with sealing operation are of vital significance due to their function in mechanics. The most universal, simple, and cheap solution of seals are O-rings. They are most commonly used for all seals. The article evaluates the operation characteristics of an O-ring seals under operation with oils containing MoS2 nanoparticles. The measurements were made on the sealing node model in a hydraulic cylinder where the round cross section seal cooperated with the piston rod. The changes of the friction force during rod movement resulting from the friction between the seal and the rod were analysed. The investigations presented in this paper allow one to conclude that, for the assumed research conditions, the average values of the friction force during instroke are higher for PAO oil with MoS2 additive in comparison to pure PAO base oil. In addition, the boundary velocity of the rod above in which the decrease of friction force was observed is higher for pure PAO oil.


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