Behavior of innovative T-shaped multi-partition steel-concrete composite columns under concentric and eccentric compressive loadings

[EN] T-shaped multi-partition steel-concrete composite column, composed of several concrete-filled rectangular steel hollow sections, is considered as an innovative composite member with the ability to accommodate neighboring wall thickness with great easiness. This paper intends to study the behavior of this innovative composite member under concentric and eccentric compressive loadings. A finite element (FE) analysis model accounting for the influences of confinement effects, geometric and material nonlinearities is developed using the program ABAQUS. The ultimate strength and load-strain responses predicted from the analysis are validated against the test results in the experiments conducted by the authors. The comparisons indicate that the FE model reasonably estimates the responses of the concentrically and eccentrically loaded T-shaped multi-partition steel-concrete composite columns. The verified model is then utilized to numerically investigate the working mechanism of the columns. The load distribution between the infilled concrete and the steel tubes and the stress distribution of the concrete during the loading process are analyzed. Moreover, parametric studies are performed to investigate the behavior of T-shaped multi-partition steel-concrete composite columns under different loadings. The studied parameters include steel to concrete area ratio, concrete compressive strength, steel yield strength and load eccentricity. Combined with the experimental results, FE analysis and parametric studies, the design recommendations for T-shaped multi-partition steel-concrete composite columns under different loadings are proposed.The research work reported in this paper were supported by National Key Research and Development Program (2016YFC0701201), and National Natural Science Foundation of China (Grant No. 51578187); their financial supports are highly appreciated.Chen, J.; Zhang, S.; Huang, Z.; Zhang, X.; Guo, L. (2018). Behavior of innovative T-shaped multi-partition steel-concrete composite columns under concentric and eccentric compressive loadings. En Proceedings of the 12th International Conference on Advances in Steel-Concrete Composite Structures. ASCCS 2018. Editorial Universitat Politècnica de València. 289-296. https://doi.org/10.4995/ASCCS2018.2018.7004OCS28929

Recent advances in the repair of degenerative intervertebral disc for preclinical applications

The intervertebral disc (IVD) is a load-bearing, avascular tissue that cushions pressure and increases flexibility in the spine. Under the influence of obesity, injury, and reduced nutrient supply, it develops pathological changes such as fibular annulus (AF) injury, disc herniation, and inflammation, eventually leading to intervertebral disc degeneration (IDD). Lower back pain (LBP) caused by IDD is a severe chronic disorder that severely affects patients’ quality of life and has a substantial socioeconomic impact. Patients may consider surgical treatment after conservative treatment has failed. However, the broken AF cannot be repaired after surgery, and the incidence of re-protrusion and reoccurring pain is high, possibly leading to a degeneration of the adjacent vertebrae. Therefore, effective treatment strategies must be explored to repair and prevent IDD. This paper systematically reviews recent advances in repairing IVD, describes its advantages and shortcomings, and explores the future direction of repair technology

Beyond the abolition of dual administration: The challenges to NGO governance in 21st century China

The abolition of dual administration of non-governmental organizations (NGOs) in China is an inexorable and essential trend toward a genuine civil society. This article seeks to examine the challenges that come with the abolition of the dual administration and to explore how to address them during this transitional period. It considers the state dominated NGO governance in China and its transformation since the 1990s and argues that the decisive role the government plays in NGOs’ development, which is criticized by many scholars, is the outcome of Chinese history, political culture and the needs of NGOs. It gives account of the challenges for NGO governance and development following the abolition of dual administration. Suggestions for new approaches to NGO development are discussed from the perspectives of a value-based partnership between NGOs and the government, the importance of securing public trust, the development of legal systems and finally, the role of NGO network organizations

Effects of background gas on sulfur hexafluoride removal by atmospheric dielectric barrier discharge plasma

The effects of background gases (He, Ar, N2 and air) on SF6 removal in a dielectric barrier reactor were investigated at atmospheric pressure. A comparison among these background gases was performed in terms of discharge voltage, discharge power, mean electron energy, electron density, removal efficiency and energy yield for the destruction of SF6. Results showed that the discharge voltage of He and Ar was lower than that of N2 and air, but the difference of their discharge power was small. Compared with three other background gases, Ar had a relatively superior destruction and removal rate and energy yield since the mean electron energy and electron density in SF6/H2O/Ar plasma were both maintained at a high level. Complete removal of 2% SF6 could be achieved at a discharge power of 48.86 W with Ar and the corresponding energy yield can reach 4.8 g/kWh

Wide-viewing integral imaging system using polarizers and light barriers array

Abstract Background Integral imaging is considered one of the most promising three-dimensional display technologies, while the limited viewing angle is regarded as a primary disadvantage of integral imaging display to reach a commercial level. This paper proposes a viewing angle enhancement method for both liquid crystal display (LCD) and the projection-type three-dimensional integral imaging system. Methods The proposed wide-viewing integral imaging system is established by using the lenslet array coupling with the polarizers, light barriers, and enlarged elemental images array. The size of light barrier and polarizer is equal to the pitch of each lenslet, the light barrier prevents light rays from passing through, and the polarizer controls the passage of light ray in the specific polarization direction. In the projection-type integral imaging system, two orthogonal elemental images arrays (EIA) are projected onto the projection screen simultaneously by the corresponding projectors. In LCD integral imaging system, two orthogonal EIAs are displayed by use of an LCD screen which can switch the polarization direction of the EIA by time-multiplexed technology within the time constant of the eyes’ response time. Results The viewing angle can be enlarged dramatically by the improvement of the size of each elemental image according to the integral imaging principles. The experimental result shows that the proposed method exhibits approximately four times the viewing angle of conventional integral imaging with the same lens array. Conclusions The increment of viewing angle can be determined by the number of light barriers between two adjacently orthogonal polarizers, the more the light barrier, the larger the viewing angle

The abolition of dual administration of NGOs in China: Imperatives and challenges

The abolition of dual administration of NGOs in China has brought it with many challenges for development and governance of NGOs. In the context of China, the decisive role the government plays in NGOs development, which is criticized by many scholars, is the result of the Chinese history, political culture and also the need of NGOs. Suggestions for new approaches to NGO development with the abolition of dual administration are thus discussed from the perspective of value-based partnership between NGOs and the government, and securing public trust