Free Oscillations of a Toroidal Viscoelastic Shell with a Flowing Liquid
Safarov Ismail Ibrahimovich,
Teshaev Muhsin Khudoyberdiyevich,
Akhmedov Maqsud Sharipovich
Issue:
Volume 6, Issue 2, June 2018
Pages:
27-39
Received:
20 March 2018
Accepted:
30 March 2018
Published:
7 May 2018
Abstract: On the basis of the method of orthogonal sweep and the Mueller method, the solution of the problem of intrinsic oscillation of a Toroidal shell with a flowing liquid is discussed. The problem of determining the frequencies and forms of intrinsic bending vibrations in the plane of curvature of curvilinear sections of thin-walled Toroidal shells of large diameter with a flowing liquid, with different conditions for fixing the end sections is solved. The behavior of complex Eigen frequencies as a function of the curvature of the shell axis is studied.
Abstract: On the basis of the method of orthogonal sweep and the Mueller method, the solution of the problem of intrinsic oscillation of a Toroidal shell with a flowing liquid is discussed. The problem of determining the frequencies and forms of intrinsic bending vibrations in the plane of curvature of curvilinear sections of thin-walled Toroidal shells of l...
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Growing Fresh Water Microalgae in High Ammonium Landfill Leachate
Zareen Taj Khanzada,
Süleyman Övez
Issue:
Volume 6, Issue 2, June 2018
Pages:
40-51
Received:
27 June 2018
Accepted:
17 July 2018
Published:
28 August 2018
Abstract: Municipal landfills are being employed for the disposal of communities solid waste. The compacted waste in landfills naturally generate leachate (liquid) which contain high concentrations of ammonium-nitrogen NH4+-N along with other toxic compounds. NH4+-N can be used as a cheap nitrogen source for microalgae biomass production, thereby facilitating tertiary treatment of landfill leachate. Two sets of studies, laboratory scale and pilot scale open raceway pond cultivation, were conducted to evaluate the potential of indigenous fresh water microalgal species to grow in ultra-membrane treated landfill leachate TL and simultaneously remove nutrients (NH4+-N-NO3- etc.). Microalgae growth was better in 50% diluted TL (1.5 gL-1 dry biomass) with 66.27% NH4+-N removal in the lab study. Onsite raceway pond cultivation had reduced biomass growth and nutrient removal. Nitrate-nitrogen NO3-N removal was minimum from both the setups. Microalgal assimilation and nitrification was the main cause of NH4+-N removal from both the setups. When lab study duration was extended, NH4+-N was found to be released back into the leachate medium. Batch cultures (when prolonged) were observed to be not an effective nutrient removal strategy in terms of NH4+-N removal via microalgal system. Further research is needed to optimize microalgal growth and nutrient removal from landfill leachate.
Abstract: Municipal landfills are being employed for the disposal of communities solid waste. The compacted waste in landfills naturally generate leachate (liquid) which contain high concentrations of ammonium-nitrogen NH4+-N along with other toxic compounds. NH4+-N can be used as a cheap nitrogen source for microalgae biomass production, thereby facilitatin...
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Study on Force Characteristics of Buried Pipeline Under Impact Load Caused by Bridge Pile Foundation Construction
Issue:
Volume 6, Issue 2, June 2018
Pages:
52-57
Received:
17 October 2018
Published:
18 October 2018
Abstract: In the pile foundation construction of highway bridge, the impact hammer falls from a certain height, which produces a great impact when it collides with soil. In order to gain a clear idea of force characteristics of buried pipeline under impact load caused by bridge pile foundation construction, the effect of construction impacting load on buried pipeline is analyzed theoretically. Firstly, taking advantage of Boussinesq solution and Mindlin solution, the distribution of additional load on the surface of pipeline under impact load is analyzed, and the transmission and diffusion of impact force in soil are calculated by elastic half-space theory. Secondly, the mechanical models of buried pipeline under surface impacting and pile hole impacting are established respectively. Combined with Boussinesq equation, Mindlin calculation and infinite beam elastic foundation model, the calculation formula of buried pipeline under impact load is obtained. Finally, according to the formula established above, an example is given to calculate the additional bending moments and axial tension and compression stresses of buried pipeline caused by bridge pile foundation construction, so as to estimate the effect of construction impacting load on buried pipeline. The research results provide some guidance for the stress analysis of buried pipelines under such construction conditions.
Abstract: In the pile foundation construction of highway bridge, the impact hammer falls from a certain height, which produces a great impact when it collides with soil. In order to gain a clear idea of force characteristics of buried pipeline under impact load caused by bridge pile foundation construction, the effect of construction impacting load on buried...
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