Extended mixed-culture biofilms (MCB) model to describe integrated fixed film/activated sludge (IFAS) process behaviour

2009 ◽  
Vol 60 (12) ◽  
pp. 3233-3241 ◽  
Author(s):  
J. Albizuri ◽  
M. C. M. van Loosdrecht ◽  
L. Larrea
Keyword(s):  
Mixed Culture ◽  
Heterotrophic Bacteria ◽  
Experimental Results ◽  
Extended Model ◽  
Test Results ◽  
Competition For Space ◽  
Aerobic Reactor ◽  
Colloidal State ◽  
Attachment Coefficient ◽  
And Diffusion

This paper presents how, in a calibration process, different assumptions regarding the standard Mixed-Culture Biofilms (MCB) model were able to match the average results at a continuous Johannesburg pilot plant (comprising two aerobic reactors, AE1 and AE2), but failed to match the batch test results of either the rate of endogenous carbonaceous oxygen uptake (OUR) or the rate of nitrate production (NPR). Under the first assumption, where attachment and diffusion of particulate components were not used, the OUR in the biofilm of the first aerobic reactor (AE1) was too low due to the absence of slowly biodegradable COD (XS) attachment flux. In a second assumption, where high diffusion and attachment coefficients were used, the NPR in the biofilm of the AE1 reactor exceeded the experimental value due to the high attachment flux used for nitrifiers (XA) and the low competition for space from XS and heterotrophic bacteria (XH). The only way to match all the experimental results was through the use of a higher attachment coefficient for XS in the first reactor (AE1), but this was considered unreasonable. Hence, an extended model was developed where a colloidal state, which interacts at the same time with the flocs and the biofilm through attachment-detachment processes, is distinguished. This model allowed the experimental results to be matched, but using the same value for the attachment coefficients of all particulate components.

scholarly journals Evaluation of leaching behavior and immobilization of zinc in cement-based solidified products

2012 ◽  
Vol 66 (5) ◽  
pp. 781-786 ◽  
Author(s):  
Damir Barbir ◽  
Pero Dabic ◽  
Petar Krolo
Keyword(s):  
Diffusion Coefficients ◽  
Experimental Results ◽  
Leaching Test ◽  
Test Results ◽  
Zeolite A ◽  
Leaching Behavior ◽  
Zn Diffusion ◽  
Cumulative Release ◽  
Electroplating Sludge ◽  
And Diffusion

This study has examined leaching behavior of monolithic stabilized/solidified products contaminated with zinc by performing modified dynamic leaching test. The effectiveness of cement-based stabilization/solidification treatment was evaluated by determining the cumulative release of Zn and diffusion coefficients, De. The experimental results indicated that the cumulative release of Zn decreases as the addition of binder increases. The values of the Zn diffusion coefficients for all samples ranged from 1.210-8 to 1.1610-12 cm2 s-1. The samples with higher amounts of binder had lower De values. The test results showed that cement-based stabilization/solidification treatment was effective in immobilization of electroplating sludge and waste zeolite. A model developed by de Groot and van der Sloot was used to clarify the controlling mechanisms. The controlling leaching mechanism was found to be diffusion for samples with small amounts of waste material, and dissolution for higher waste contents.

Experimental Study and Finite Analysis on Flexural Capacity of Laminated Glass

2011 ◽  
Vol 243-249 ◽  
pp. 258-262
Author(s):  
Jun Chen ◽  
Jia Lv ◽  
Qi Lin Zhang ◽  
Zhi Xiong Tao ◽  
Jun Chen
Keyword(s):  
Experimental Results ◽  
Laminated Glass ◽  
Test Results ◽  
Design Code ◽  
Flexural Capacity ◽  
Equivalent Thickness ◽  
High Rise ◽  
Safety Glass ◽  
Current Design ◽  
Good Agreement

Laminated glass has been increasing widely used in high rise buildings as a kind of safety glass in recent years. So we should analyze its material property. In this paper, we use flexural experiments and ANSYS program to analyze the main factors that affect the flexural capacity of the laminated glass. The test results show that the flexural capacity is closely related to film. And the ANSYS program had got good agreement with the experimental results. Comparison of experimental results with calculated ones indicates that the current design code will lead to conservative results and the equivalent thickness of laminated glasses provided in the code should be further discussed.

An Analysis of Conventional and Self-Aligned four Terminal Resistor Structures for The Determination of The Contact Resistivity from End Resistance Measurements

1986 ◽  
Vol 71 ◽  
Author(s):  
I. Suni ◽  
M. Finetti ◽  
K. Grahn
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Computer Model ◽  
Contact Resistivity ◽  
Experimental Results ◽  
The Finite Element Method ◽  
Model Based ◽  
A Value ◽  
And Diffusion

AbstractA computer model based on the finite element method has been applied to evaluate the effect of the parasitic area between contact and diffusion edges on end resistance measurements in four terminal Kelvin resistor structures. The model is then applied to Al/Ti/n+ Si contacts and a value of contact resistivity of Qc = 1.8×10−7.Ωcm2 is derived. For comparison, the use of a self-aligned structure to avoid parasitic effects is presented and the first experimental results obtained on Al/Ti/n+Si and Al/CoSi2/n+Si contacts are shown and discussed.

scholarly journals In-plane Shear Strengthening of Unreinforced Masonry Walls Using GFRP Jacketing

2017 ◽  
Author(s):  
Enea Mustafaraj ◽  
Yavuz Yardim
Keyword(s):  
Experimental Results ◽  
Test Results ◽  
Compression Tests ◽  
Shear Strengthening ◽  
Plane Shear ◽  
Standard Size ◽  
Reinforced Polymer ◽  
Glass Fiber Reinforced ◽  
Diagonal Compression ◽  
Before And After

In this paper, it is presented the experimental results of a campaign on diagonal compression tests, as of ASTM E519-02, to assess and compare the in-plane behavior of standard size of 1200 × 1200 × 250 mm, for three unreinforced and three reinforced wall panels by glass fiber reinforced polymer (GFRP) embedded in an inorganic matrix.From the diagonal compression test results, were determined some of the main mechanical parameters such as: shear strength, modulus of rigidity and ductility, before and after application of the reinforcement.The experimental results showed that the GFRP reinforced panels exhibited a significant increase of 127% in shear resistance, 1100% in ductility and 650% in modulus of rigidity when compared to unreinforced panels.It was concluded that this technique provided satisfactory results and can be considered a suitable method for repair of masonry structures.

Experimental Study of Fatigue Performance of Stay Cable Damper

2014 ◽  
Vol 487 ◽  
pp. 404-407
Author(s):  
Dong Liang ◽  
Zi Shuo Li
Keyword(s):  
Experimental Study ◽  
Good Condition ◽  
Experimental Results ◽  
Test Results ◽  
Stay Cable ◽  
Damping Force ◽  
Durability Test ◽  
Equivalent Damping ◽  
Stay Cables ◽  
Performance Deterioration

Oil dampers are widely used as a popular countermeasure to mitigate the stay cables vibration. In this study, one actual oil damper designed for some long cable-stayed was experimentally investigated to evaluate the durability. 4 million cycles loading, with frequency of 4 Hz and amplitude of 1 mm, was imposed on the damper. The excitation displacement and damping force were measured and the equivalent damping was calculated from the experimental results. The stiffness effects of dampers behaved during durability tests were also analyzed quantitatively. The test results showed that the dampers were still in good condition after 4 million cycles loading and the dampers temperatures were stable at 50 degree centigrade during the test. According to the durability test results, a model for performance deterioration of damper was proposed to predict the lifetime of oil dampers.

Experimental Evaluation of Evaporative Cooler Using Agro Materials

2015 ◽  
Vol 23 (04) ◽  
pp. 1550028 ◽  
Author(s):  
R. Ramkumar ◽  
M. Kesavan ◽  
A. Ragupathy
Keyword(s):  
Ambient Condition ◽  
Experimental Results ◽  
Test Results ◽  
Test Rig ◽  
Air Velocity ◽  
Different Types ◽  
Saturation Efficiency ◽  
Evaporative Cooler ◽  
Luffa Sponge ◽  
Efficiency Improve

The purpose of the study is to investigate the direct evaporate cooler in hot and humid regions with two different types of agro-based materials. In our experimental study, the locally available agro materials luffa (Sponge Gourd), zizanioides (Vetiver) were used with various thickness and the experimental results were compared with mathematical values. The operating parameters of pad thickness, air velocity, were changed and the performance of the cooler was analyzed. A test rig was designed and fabricated to collect experimental data. The performance of the evaporative cooler was evaluated based on the ambient condition. The analysis of the data indicated that cooling saturation efficiency improve with decrease of air velocity and higher pad thickness. It was shown that zizanioides-based pad with 160[Formula: see text]mm thickness has the higher performance (88%) at 4.5[Formula: see text]m/s air velocity in comparison with luffa pad materials. The experimental results of outlet air temperature and number of transfer units (NTU) were compared with mathematical model. The test results were within the limit of 15% and 10% to mathematical values.

scholarly journals Behavior of wood beam connection using staples subjected to in-plane moment

2019 ◽  
Vol 258 ◽  
pp. 05008
Author(s):  
Farida Lenggani ◽  
Bambang Suryoatmono
Keyword(s):  
Failure Mode ◽  
Failure Modes ◽  
Solid Wood ◽  
Experimental Results ◽  
Elastic Analysis ◽  
Connection Strength ◽  
Test Results ◽  
Lateral Resistance ◽  
Wood Beams ◽  
Mechanical Fasteners

It is very frequent that solid wood beams need to be connected one to another to obtain a longer beam. In this study, the behavior of solid wood beams connections using plywood sheets as connecting elements and staples as mechanical fasteners were studied experimentally. The experimental results were compared with elastic analyses. Both beam and plywood were made of meranti (shorea). The staple type was MAX 1022J. This study was conducted on two specimens. The first specimen had two rows of staples on the front and back sides of the specimen. Each row consisted of ten staples making a total of 40 staples. The second one had three rows of staples on the front and back sides of the specimen. Each row consisted of ten staples making a total of 60 staples. From the tests, it can be concluded that each material in the connection, namely wood beam, plywood, and staples, failed. Failure mode of the wood beam was in the form of crack and tear. Failure mode of the plywood was the damage of the plywood directly contacted with the crown of the staples. Failure modes of the staples were flexural yielding. The differences between connection strength obtained from tests and elastic analyses were 8.18% for the first specimen and 0.65% for the second specimen, with the test results were higher than the elastic analyses results. It can be concluded that elastic analysis is quite accurate and conservative to estimate the strength of this type of connection, provided that the lateral resistance of connection with a staple is known.

POLARIZATION CAPACITANCE OF DOPED POTASSIUM BROMIDE CRYSTALS

1966 ◽  
Vol 44 (5) ◽  
pp. 965-970 ◽  
Author(s):  
H. J. Wintle ◽  
J. Rolfe
Keyword(s):  
Diffusion Coefficient ◽  
Space Charge ◽  
Potassium Bromide ◽  
Space Charge Polarization ◽  
Experimental Results ◽  
Charge Polarization ◽  
Polarization Capacity ◽  
And Diffusion

Measurements have been made of the capacitance and conductance at 200 c.p.s. of a series of potassium bromide crystals doped with divalent anion and cation impurities. The dependence of the space-charge polarization capacity, caused by blocking of current carriers at the electrodes, on the conductivity and diffusion coefficient of carriers has been established. It is concluded that linearized theories of space-charge polarization cannot explain the experimental results.

scholarly journals Experimental Work Conducted on MgO Characterization and Hydration

2008 ◽  
Vol 1124 ◽  
Author(s):  
Haoran Deng ◽  
Yongliang Xiong ◽  
Martin Nemer ◽  
Shelly Johnsen
Keyword(s):  
Control Agent ◽  
Department Of Energy ◽  
Fractional Factorial ◽  
Test Results ◽  
Waste Isolation Pilot Plant ◽  
Large Particles ◽  
Series Of Experiments ◽  
Engineered Barriers ◽  
And Diffusion ◽  
Transuranic Waste

AbstractMagnesium oxide (MgO) is the only engineered barrier certified by the EPA for emplacement in the Waste Isolation Pilot Plant (WIPP), a U.S. Department of Energy repository for transuranic waste. MgO will reduce actinide solubilities by sequestering CO2 generated by the biodegradation of cellulosic, plastic, and rubber materials. Demonstration of the effectiveness of MgO is essential to meet the U.S Environmental Protection Agency's requirement for multiple natural and engineered barriers. In the past, a series of experiments was conducted at Sandia National Laboratories to verify the efficacy of Premier Chemicals LLC (Premier) MgO as a chemical-control agent in the WIPP. Since December 2004, Premier MgO is no longer available for emplacement in the WIPP. Martin Marietta Magnesia Specialties LLC is the new MgO supplier. MgO characterization, including chemical, mineralogic, and reactivity analysis, has been performed to address uncertainties concerning the amount of reactive constituents in Martin Marietta MgO. Characterization results of Premier MgO will be reported for comparison. Particle size, solid-to-liquid ratio, and stir speed could affect the rate of carbonation of MgO slurries. Thus, it's reasonable to hypothesize that these factors will also affect the rate of hydration. Accelerated MgO hydration experiments were carried out at two or three levels for each of the above factors in deionized water at 70 °C. The Minitab statistical software package was used to design a fractional-factorial experimental matrix and analyze the test results. We also fitted the accelerated inundated hydration data to four different kinetic models and calculated the hydration rates. As a result of this study we have determined that different mechanisms may be important for different particle sizes, surface control for large particles and diffusion for small particles.

Test Results on the ARL 19 Supersonic Blade Cascade

1988 ◽  
Vol 110 (4) ◽  
pp. 450-455 ◽  
Author(s):  
A. Fourmaux ◽  
R. Gaillard ◽  
G. Losfeld ◽  
G. Meauze´
Keyword(s):  
Theoretical Analysis ◽  
Data Reduction ◽  
Experimental Results ◽  
Test Facility ◽  
Experimental Program ◽  
Test Model ◽  
Test Results ◽  
Blade Cascade

This paper presents the ONERA contribution in a joint experimental program on the aerodynamics of supersonic airfoil cascades. The first part deals with the specific ONERA way of running cascade tests: description of the test facility, the test model, the instrumentation, and data reduction. Then, after a brief theoretical analysis of the ARL 19 cascade, some experimental results are presented and discussed.

Sign in / Sign up

Export Citation Format

Share Document