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1

Experimental research on energy release characteristics of water-bearing sandstone alongshore wharf

Wang S., Zhao Y., Zou Z., Jia H.

Polish Maritime Research

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2017

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S 2

147--153

EN

It is important to evaluate the deformation and failure of sandstone in the foundation engineering of coast, river bank and lake shore. While the deformation and failure of sandstone is a comprehensive result of energy release and dissipation, and energy release is the internal reason which leads to global failure of the sandstone. The experimental analysis is conducted on the character of energy revolution of the sandstone specimen by rating loading and unloading, and the catastrophe model is followed in analyzing elastic strain energy accumulation and release in rock deformation and failure. The index based on elastic energy release is proposed to assess the rock brittleness. It is found that increasing water content is to relieve energy release and catastrophe failure of the rock specimen, and weakening the capacity of elastic energy storage. The peak and residual values of elastic energy are raised as the confining pressure increases, and the post-peak released energy decreases progressively. The confining pressure strengthens energy storage and inhibits energy release of the rock specimen, and saturation of rock will weaken this inhibit effect. The brittleness index decreases with increasing confining pressure as the rock specimen transforming from brittle to ductile.

2

Influence of Rolling Friction Coefficient on Inter-Particle Percolation in a Packed Bed by Discrete Element Method

Zhou H., Luo Z., Zhang T., You Y., Li H., Zou Z.

Archives of Metallurgy and Materials

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2016

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Vol. 61, iss. 4

1795--1804

EN

Rolling friction representing the energy dissipation mechanism with the elastic deformation at the contact point could act directly on particle percolation. The present investigation intends to elucidate the influence of rolling friction coefficient on inter-particle percolation in a packed bed by discrete element method (DEM). The results show that the vertical velocity of percolating particles decreases with increasing the rolling friction coefficient. With the increase of rolling friction coefficient, the transverse dispersion coefficient decreases, but the longitudinal dispersion coefficient increases. Packing height has a limited effect on the transverse and longitudinal dispersion coefficient. In addition, with the increase of size ratio of bed particles to percolation ones, the percolation velocity increases. The transverse dispersion coefficient increases with the size ratio before D/d<14. And it would keep constant when the size ratio is greater than 14. The longitudinal dispersion coefficient decreases when the size ratio increases up to D/d=14, then increases with the increase of the size ratio. External forces affect the percolation behaviours. Increasing the magnitude of the upward force (e.g. from a gas stream) reduces the percolation velocity, and decreases the dispersion coefficient.

3

Effect Of Low-Temperature Annealing On The Properties Of Ni-P Amorphous Alloys Deposited Via Electroless Plating

Zhao G., Zou Y., Zhang H., Zou Z.

Archives of Metallurgy and Materials

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2015

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Vol. 60, iss. 2A

865--869

EN

Amorphous Ni-P alloys were prepared via electroless plating and annealing at 200°C at different times to obtain different microstructures. The effects of low-temperature annealing on the properties of amorphous Ni-P alloys were studied. The local atomic structure of the annealed amorphous Ni-P alloys was analyzed by calculating the atomic pair distribution function from their X-ray diffraction patterns. The results indicate that the properties of the annealed amorphous Ni-P alloys are closely related to the order atomic cluster size. However, these annealed Ni-P alloys maintained their amorphous structure at different annealing times. The variation in microhardness is in agreement with the change in cluster size. By contrast, the corrosion resistance of the annealed alloys in 3.5 wt% NaCl solution increases with the decrease in order cluster size.

PL

Amorficzne stopy Ni-P otrzymane metodą powlekania bezprądowego wyżarzano w temperaturze 200°C w różnych czasach, w celu otrzymania zróżnicowanej mikrostruktur. Badano wpływ mikrostruktury wyżarzanych stopów amorficznych Ni-P na ich odporność korozyjną w roztworze 3,5% wag. NaCl. Wyniki wskazują, że wielkość klastra w wyżarzanych stopach amorficznych Ni-P najpierw zmniejszyła się, a następnie zwiększyła wraz z czasem wyżarzania. Odporność badanych stopów na korozję jest ściśle związana z wielkością klastra, mimo, że stopy te po wyżarzaniu w różnych czasach zachowują strukturę amorficzną. Odporność wyżarzanych stopów amorficznych Ni-P w roztworze 3,5% wag. NaCl zwiększa się wraz ze zmniejszeniem się klastra.

4

Effect of Some Variables on the Fibre Packing Pattern in a Yarn Cross-section for Vortex Spun Yarn

Zou Z., Zheng S, Cheng L, Xi B, Yao J.

Fibres & Textiles in Eastern Europe

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2014

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Vol. 22, no. 2 (104)

40--46

EN

This paper examined the influence of various parameters such as fibre fineness, yarn count, distance from the front roller nip point to the hollow spindle, nozzle pressure and yarn delivery speed on the fibre packing pattern in a yarn cross-section for vortex spun yarn. Cross-section images of vortex spun yarns were used to evaluate the fibre packing pattern. Results from different variables influencing the fibre packing pattern for vortex spun yarn were also analysed. The results indicated that the fibre fineness, yarn count, distance from the front roller nip point to the hollow spindle, nozzle pressure and yarn delivery speed are all significant parameters for yarn hairiness and fibre packing density in a vortex spun yarn cross-section.

PL

Badano wpływ grubości włókien, masy liniowej przędzy, odległości przedniej rolki do wydrążonego wrzeciona, ciśnienia w dyszy i szybkości podawania przędzy na upakowanie włókien w przekroju poprzecznym przędzy przędzionej systemem vortex. Zdjęcia przekrojów poprzecznych przędzy zostały wykorzystane dla oceny upakowania włókien. Wyniki analizy rozkładów włókien wykazały, że wszystkie badane parametry mają wydatny wpływ na upakowanie i włochatość w przędzy przędzionej systemem vortex.

5

Numerical study on the influences of canal geometry on ship squat

Zhou M., Zou Z.

Zeszyty Naukowe / Akademia Morska w Szczecinie

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2013

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nr 36 (108) z. 1

195--199

EN

Accurate prediction of the ship squat is of significance to ensure safety passage of ships in restricted waters. In this paper, a first-order Rankine source panel method is adopted to predict the squat of a ship sailing in restricted canal. Taking KVLCC2 tanker as example, numerical calculations are carried out for the ship travelling in a canal with different conditions. The results of squat are compared with measurement data and the results from empirical formulas. The influence of canal geometry on ship squat is investigated.