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2021 ◽  
Author(s):  
Birger Opgård ◽  
Gaute Mo ◽  
Fernando Ibáñez Climent ◽  
Altea Cámara Aguilera

<p>The Stovner Tower forms part of an activity park in the Stovner district of Oslo. The tower, providing a serpentine walkway through the treetops with a maximum height of 15m, is designed to be universally accessible. The route is based on a series of straight lengths connected with abrupt changes of direction. The 2m wide walkway has an overall length of 270m with a constant 1:15 slope. There are four intermediate horizontal platforms intended as relaxation and viewing areas, each one with different sizes. The principal deck structure is steel, formed from a central tube with a diameter of 762mm. The tube is made up of a series of 2m long straight segments which form the walkway change of direction. Steel cantilever ribs are located at 1.5m centres to support both the solid timber decking and the 1.3m high guardrail. The central steel tube is supported at multiple locations by tripod columns formed from GL32c glulam timber sections varying from 200x200mm to 350x350mm. The timber columns are anchored to the bedrock located close to the surface in this area. Steel walkway sections were shop welded in transportable lengths with bolted on- site connections. Timber to steel connections were also bolted. Steel is painted for corrosion protection. All timber, both solid C24 for decking and glulam columns, is treated for external use. A 3D SAP2000 FE model was used for verifications including a buckling analysis for the slender timber columns and a modal analysis to check for frequencies that would make the structure susceptible to pedestrian-induced vibrations.</p>


2021 ◽  
Vol 136 (5) ◽  
pp. 48-52
Author(s):  
A. B. Golovanchikov ◽  
◽  
N. A. Prokhorenko ◽  

A typical algorithm for calculating a two-pipe heat exchanger is supplemented with technical and economic parameters related to annual costs for electricity, depreciation costs for equipment and working capital for repairs and maintenance. An example of the calculation with heating of the oil stream before distillation of the bottom heavy fraction obtained at the outlet of the column is given. The calculation results are presented in the form of dependencies of the main technical and economic parameters: hydraulic resistance, pump power, pipe length on the central tube inner diameter, in which heated crude oil moves counter currently with the bottom of the bottom of the bottom fluid.


2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Rong Hu ◽  
Haipeng Xu ◽  
Yaheng Jiang ◽  
Yi Chen ◽  
Kelin He ◽  
...  

Peripheral nerve networks (PNNs) play a vital role in the neural recovery after spinal cord injury (SCI). Electroacupuncture (EA), as an alternative medicine, has been widely used in SCI and was proven to be effective on neural functional recovery. In this study, the interaction between PNNs and semaphrin3A (Sema3A) in the recovery of the motor function after SCI was observed, and the effect of EA on them was evaluated. After the establishment of the SCI animal model, we found that motor neurons in the ventral horn of the injured spinal cord segment decreased, Nissl bodies were blurry, and PNNs and Sema3A as well as its receptor neuropilin1 (NRP1) aggregated around the central tube of the gray matter of the spinal cord. When we knocked down the expression of Sema3A at the damage site, NRP1 also downregulated, importantly, PNNs concentration decreased, and tenascin-R (TN-R) and aggrecan were also reduced, while the Basso-Beattie-Bresnahan (BBB) motor function score dramatically increased. In addition, when conducting EA stimulation on Jiaji (EX-B2) acupoints, the highly upregulated Sema3A and NRP1 were reversed post-SCI, which can lessen the accumulation of PNNs around the central tube of the spinal cord gray matter, and simultaneously promote the recovery of motor function in rats. These results suggest that EA may further affect the plasticity of PNNs by regulating the Sema3A signal and promoting the recovery of the motor function post-SCI.


2020 ◽  
Vol 14 (Supplement_1) ◽  
pp. S137-S137
Author(s):  
F WEIß ◽  
I F M Lee ◽  
A Fromm ◽  
J C E Hu ◽  
T Breiderhoff ◽  
...  

Abstract Background In Inflammatory bowel disease, intestinal homeostasis cannot be sustained due to an overreaction of the immune system and a disturbed epithelial barrier due to an impaired tight junction (TJ). At tricellular TJs (tTJs), which are formed where three cells meet, the TJ network is basolaterally expanded and forms a central tube which would be potentially large enough to allow for a paracellular passage of macromolecules. Under normal conditions, the tTJ protein tricellulin (Tric) seals the central tube against luminal uptake. However, in ulcerative colitis (UC), Tric is downregulated, resulting in increased uptake of macromolecules including antigens which may further support the inflammatory processes. Thus, we aimed to identify whether or not overexpression of Tric has a protective effect against inflammation. Methods We generated intestinal epithelial cell-specific overexpression of Tric in mice (B6.C-Tg(Vil-cre) Rosa26tgGFP-Tric). In Tric-overexpressing (Tric-OE) and in wild-type (wt) mice experimental colitis was induced by 3% dextran sodium sulphate (DSS) for 6 days. The effect was assessed by determining the disease activity index (DAI: weight loss, stool consistency, and stool bleeding) and the colon dimensions. Using chamber experiments were performed to determine permeabilities for ions and macromolecules of different sizes (4 and 10 kDa). Results No difference in weight loss was observed between wt and Tric-OE mice upon DSS treatment. However, Tric-OE mice suffered less from diarrhoea and had less bloody stools compared with wt mice resulting in a lower DAI. In addition, DSS caused a reduced colon length which was less prominent in Tric-OE mice than in wt mice. Functional analysis revealed higher permeabilities for Na+ and Cl− after DSS treatment with no significant differences between Tric-OE and wt mice. In contrast, permeabilities for macromolecules of both sizes were unchanged after DSS treatment in Tric-OE mice but elevated in wt-mice. Conclusion Tric-overexpression prevents the epithelial barrier from elevated paracellular uptake of macromolecules during DSS colitis without affecting ion permeability. This protects against DSS colitis as indicated by less affected clinical and structural outcome parameters, most likely via a reduction in a load of immunologically active macromolecules in the subepithelium.


2020 ◽  
Vol 328 ◽  
pp. 01010
Author(s):  
Peter Mlynár ◽  
František Világi ◽  
Zdenko Závodný ◽  
František Urban ◽  
František Ridzoň

To safely and efficiently load the fuel assemblies of the VVER 440 / V 213 nuclear reactor, the relation between the temperature of the coolant at the outlet of the fuel assembly, measured by a thermocouple in the assembly’s axis, and the mean coolant temperature, present in the plane of the thermocouple, must be analysed. Based on the analysis of the coolant flow at the output of the physical model of the fuel assembly I. [1] and published CFD simulations [2,3,4] it was shown, that a special attention has to be paid to the influence of the water flow in the central tube on the temperature and velocity profile of the coolant at the thermocouple’s plane in the fuel assembly. For this reason, an experimental device with a physical model of the fuel assembly II. of the nuclear reactor VVER 440 / V 213 was designed, manufactured, and operated at the Faculty of Mechanical Engineering STU in Bratislava.


2019 ◽  
Vol 44 (36) ◽  
pp. 20173-20182 ◽  
Author(s):  
Sophida Thiangviriya ◽  
Praphatsorn Plerdsranoy ◽  
Chongsutthamani Sitthiwet ◽  
Palmarin Dansirima ◽  
Puttimate Thongtan ◽  
...  

2019 ◽  
Vol 124 ◽  
pp. 533-540
Author(s):  
Md. Saifur Rahman ◽  
M.A. Malek Soner ◽  
M. Mizanur Rahman ◽  
Md. Al Amin Hossain ◽  
M.A. Salam ◽  
...  

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