scholarly journals Optimum Equivalent Loading in Multi-Dimensional Transmission

2020 ◽  
Vol 1 ◽  
pp. 681-699
Author(s):  
John M. Cioffi ◽  
Peter S. Chow ◽  
Kenneth J. Kerpez
Keyword(s):  
Equivalent Loading

Numerical Study of Cracked Titanium Shell under Compression

2011 ◽  
Vol 264-265 ◽  
pp. 490-495
Author(s):  
F. Ayari ◽  
Ali Zghal ◽  
E. Bayraktar
Keyword(s):  
Cylindrical Shell ◽  
Stress Intensity ◽  
Numerical Study ◽  
Applied Pressure ◽  
Economic Feasibility ◽  
Loading Conditions ◽  
Thin Cylindrical Shell ◽  
Bending Stresses ◽  
Stress And Deformation ◽  
Equivalent Loading

In many industrial conditions, light thin titanium shells are well used under various severe loading conditions. It is of interest to know the real conditions that govern the instability of a cracked panel subject to buckling loads in order to conserve as maximum as possible the strength of the structure. Several parameters can be varied in order to achieve this objective. The aim of this study is to determine the evolution of these parameters in order to achieve optimal crack propagation conditions while keeping these parameters within “reasonable” limits of physical and economic feasibility. For the purpose of the current study the considered structure can be regarded as thin cylindrical shell of radius r, thickness t with an initial through crack of length a. The titanium cylindrical shell is sealed on one edge and compression is applied on the other. An additional applied pressure can generates a stress and deformation field around the crack tip that has bending stresses and membrane stresses and appears as a bulge around the crack area. This paper give details of a simulation with FEA numerical analysis that determine governing instability conditions of a Titanium shell under particular loading conditions and to put in light the effect of bulging on the stress intensity factor at the crack tips. This bulging factor measures the severity of the stress intensity in the bulged crack compared to a plane shell subjected to equivalent loading conditions.

Performance characterization of anaerobic sequencing batch reactor process for digestion of night soil

2001 ◽  
Vol 43 (1) ◽  
pp. 27-34 ◽  
Author(s):  
J. G. Lee ◽  
J. M. Hur ◽  
D. Chang ◽  
T. H. Chung
Keyword(s):  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Ammonia Nitrogen ◽  
Gas Production ◽  
High Concentration ◽  
Anaerobic Sequencing Batch Reactor ◽  
Mixed Control ◽  
Volatile Solids ◽  
Equivalent Loading

Laboratory experiments were conducted to investigate the performance of an anaerobic sequencing batch reactor (ASBR) process for night soil treatment. Performances of the reactors were evaluated at an equivalent hydraulic retention time (HRT) of 10 days with an equivalent loading rate of 2.6 kgVS/m3/d (3.1 kgCOD/m3/day) at 35°C. Digestion of a night soil was possible using the ASBR at an HRT of 10 days in spite of high concentration of ammonia nitrogen and settleable solids. Solids were accumulated rapidly in the ASBRs, and their concentrations were 2.3∼2.4 times higher than that in a completely mixed control reactor. Remarkable increases in gas production were observed in the ASBRs compared with the control reactor. Average increases in equivalent daily gas production from the ASBRs were 205∼220% compared with that from the control run. The ASBR with reaction period/thickening period ratio (R/T ratio) of 1 showed a little higher gas production and organic removal efficiency than that with R/T ratio of 3. Volatile solids removals based on supernatant of the ASBRs were 12∼14% higher than that of the control reactor. Thus, the ASBR was a stable and effective process for the treatment of night soil having high concentration of settleable organics and ammonia nitrogen.

Digestion of municipal sludge by anaerobic sequencing batch reactor

1994 ◽  
Vol 30 (12) ◽  
pp. 161-170 ◽  
Author(s):  
Duk Chang ◽  
Joon Moo Hur ◽  
Tai Hak Chung
Keyword(s):  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Gas Production ◽  
Municipal Sludge ◽  
High Concentration ◽  
Anaerobic Sequencing Batch Reactor ◽  
Mixed Control ◽  
Solids Concentration ◽  
Start Up ◽  
Equivalent Loading

Laboratory experiments were conducted to investigate the performance of the anaerobic sequencing batch reactor (ASBR) for digestion of a municipal sludge. The reactors were operated at an HRT of 10 days with an equivalent loading rate of 0.8-1.5 g VS 1−1 d−1 at 35°C. Solids were accumulated rapidly in the ASBR during start-up period. Flotation thickening occurred in the ASBRs, and its efficiency was comparable to that of additional thickening of the completely mixed control reactor. Solids concentrations in the ASBRs were 2.6 times higher than that in the control. The dehydrogenase activity had a strong correlation with the solids concentration. The ASBRs with 3- and 4-day cycle showed almost identical high digestion performances without adverse effect on digestion stability. The organics removals based on subnatant of the ASBRs were consistently above 90%. Remarkable increase in equivalent gas production of 52% was observed at the ASBRs compared with the control though the control and ASBRs showed similar effluent quality. Thus, digestion of a municipal sludge was possible using the ASBR in spite of high concentration of settleable solids in the sludge.

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