Long-term operating conditions for different sorption materials to capture phosphate from domestic wastewater

2021 ◽  
pp. e00385
Author(s):  
Andrzej Jucherski ◽  
Andrzej Walczowski ◽  
Piotr Bugajski ◽  
Krzysztof Jóźwiakowski ◽  
Joanna Rodziewicz ◽  
...  
Keyword(s):  
Domestic Wastewater ◽  
Operating Conditions

scholarly journals Intelligent long-term performance analysis in power electronics systems

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Saeed Peyghami ◽  
Tomislav Dragicevic ◽  
Frede Blaabjerg
Keyword(s):  
Performance Indicator ◽  
Thermal Characteristics ◽  
Operating Conditions ◽  
System Level ◽  
Power Electronic ◽  
Reliability Modeling ◽  
Artificial Neural Network Ann ◽  
Long Term Performance ◽  
Term Performance

AbstractThis paper proposes a long-term performance indicator for power electronic converters based on their reliability. The converter reliability is represented by the proposed constant lifetime curves, which have been developed using Artificial Neural Network (ANN) under different operating conditions. Unlike the state-of-the-art theoretical reliability modeling approaches, which employ detailed electro-thermal characteristics and lifetime models of converter components, the proposed method provides a nonparametric surrogate model of the converter based on limited non-linear data from theoretical reliability analysis. The proposed approach can quickly predict the converter lifetime under given operating conditions without a further need for extended, time-consuming electro-thermal analysis. Moreover, the proposed lifetime curves can present the long-term performance of converters facilitating optimal system-level design for reliability, reliable operation and maintenance planning in power electronic systems. Numerical case studies evaluate the effectiveness of the proposed reliability modeling approach.

Ni-based bimetallic nano-catalysts anchored on BaZr0.4Ce0.4Y0.1Yb0.1O3−δ for internal steam reforming of methane in a low-temperature proton-conducting ceramic fuel cell

2021 ◽  
Author(s):  
Kyungpyo Hong ◽  
Stephanie Nadya Sutanto ◽  
Jeong A. Lee ◽  
Jongsup Hong
Keyword(s):  
Steam Reforming ◽  
Low Temperatures ◽  
Operating Conditions ◽  
Hydrogen Yield ◽  
Carbon Formation ◽  
Long Term Stability ◽  
Ceramic Fuel Cell ◽  
Ceramic Fuel ◽  
Nano Catalysts

Ni–Rh and Ni–Co nano-scale alloys exhibit high methane conversion, hydrogen yield, resistance to carbon formation, and long-term stability at low temperatures, allowing them to cope with the various operating conditions of direct methane-fueled PCFCs.

Efficient Analysis of a Catenary Riser

2006 ◽  
Author(s):  
Elizabeth Passano ◽  
Carl M. Larsen
Keyword(s):  
Operating Conditions ◽  
Stochastic Simulations ◽  
Worst Case ◽  
Nonlinear Structure ◽  
Tension Response ◽  
Extreme Response ◽  
Analysis Strategies ◽  
Low Tension ◽  
Term Response

The paper deals with the challenge of predicting the extreme response of catenary risers, a topic of both industry and academic interest. Large heave motions introduced at the upper end of a catenary riser can lead to compression and large bending moments in the region immediately above the touch down area. In the worst case, dynamic beam buckling may occur. The focus of the paper will be on understanding the riser behaviour in extreme, low-tension response and in establishing suitable analysis strategies to predict the extreme response. Results from long nonlinear stochastic simulations of many sea states with varying environmental and operating conditions may be combined to describe the long-term response of a nonlinear structure such as a catenary riser. However, this theoretically straight-forward approach is very demanding computationally and ways to limit the extent of nonlinear stochastic simulations are therefore sought. The usefulness of simpler methods such as regular wave analysis to improve understanding of the physical behaviour and to aid in concentrating the nonlinear simulations to where they are most useful, will be demonstrated.

Nitrite reduction and methanogenesis in a single-stage UASB reactor

2015 ◽  
Vol 72 (12) ◽  
pp. 2236-2242 ◽  
Author(s):  
L. I. Borges ◽  
C. M. López-Vazquez ◽  
H. García ◽  
J. B. van Lier
Keyword(s):  
Domestic Wastewater ◽  
High Strength ◽  
Single Stage ◽  
Nitrite Reduction ◽  
Upflow Anaerobic Sludge Blanket ◽  
Uasb Reactor ◽  
Organic Loading Rate ◽  
Anaerobic Sludge ◽  
N Removal

In this study, nitrite reduction and methanogenesis in a single-stage upflow anaerobic sludge blanket (UASB) reactor was investigated, using high-strength synthetic domestic wastewater as substrate. To assess long-term effects and evaluate the mechanisms that allow successful nitrite reduction and methanogenesis in a single-stage UASB, sludge was exposed to relatively high nitrite loading rates (315 ± 13 mgNO2−-N/(l.d)), using a chemical oxygen demand (COD) to nitrogen ratio of 18 gCOD/gNO2−-N, and an organic loading rate of 5.4 ± 0.2 gCOD/(l.d). In parallel, the effects of sludge morphology on methanogenesis inhibition were studied by performing short-term batch activity tests at different COD/NO2−-N ratios with anaerobic sludge samples. In long-term tests, denitrification was practically complete and COD removal efficiency did not change significantly after nitrite addition. Furthermore, methane production only decreased by 13%, agreeing with the reducing equivalents requirement for complete NO2− reduction to N2. Apparently, the spatial separation of denitrification and methanogenesis zones inside the UASB reactor allowed nitrite reduction and methanogenesis to occur at the same moment. Batch tests showed that granules seem to protect methanogens from nitrite inhibition, probably due to transport limitations. Combined COD and N removal via nitrite in a single-stage UASB reactor could be a feasible technology to treat high-strength domestic wastewater.

Effects of the Rolling Directions on Wear of the Aluminum Alloys

2021 ◽  
Vol 901 ◽  
pp. 193-198
Author(s):  
Yuh Ping Chang ◽  
Li Ming Chu ◽  
Chien Te Liu ◽  
Jin Chi Wang ◽  
Gao Wei Chen
Keyword(s):  
Wear Resistance ◽  
Aluminum Alloys ◽  
Rolling Direction ◽  
Optical Microscope ◽  
Operating Conditions ◽  
Crystal Phase ◽  
Transportation Industry ◽  
Key Technology ◽  
Crystal Grains

Due to the booming development of the automation industry and the transportation industry, the mechanical components are prone to wear under long-term operating conditions. To improve the wear resistance, effects of the rolling directions on wear of the aluminum alloys are studied. An optical microscope is used to analyze the crystal phase, and the correlation between the crystal grains and the rolling direction is studied. This study can therefore establish a key technology for improving the wear resistance of aluminum alloys.

Investigation of long-term operation and biomass activity in a membrane bioreactor system

2011 ◽  
Vol 63 (9) ◽  
pp. 1906-1912 ◽  
Author(s):  
Simos Malamis ◽  
Andreas Andreadakis ◽  
Daniel Mamais ◽  
Constantinos Noutsopoulos
Keyword(s):  
Membrane Fouling ◽  
Membrane Bioreactor ◽  
Extracellular Polymeric Substances ◽  
Operating Conditions ◽  
Term Operation ◽  
Solids Retention ◽  
Biomass Activity ◽  
Long Term Performance ◽  
Term Performance

The aim of this work was to evaluate the long-term performance of a Membrane Bioreactor (MBR) that operated continuously for 2.5 years and to assess membrane fouling and biomass activity under various operating conditions. Furthermore, a method for the characterisation of influent wastewater was developed based on its separation into various fractions. The MBR system operated at the solids retention times (SRT) of 10, 15, 20 and 33 days. The increase of SRT resulted in a decrease of the fouling rate associated with the reduction of extracellular polymeric substances. Moreover, the SRT increase resulted in a significant reduction of the Oxygen Uptake Rate (OUR) due to the lower availability of substrate and in a notable decrease of the maximum OUR since high SRT allowed the development of slower growing microorganisms. Biomass consisted of small flocs due to extensive deflocculation caused by intense aeration. Finally, the method developed for wastewater characterisation is straightforward and less time consuming than the usual method that is employed.

A focus on pressure-driven membrane technology in olive mill wastewater reclamation: state of the art

2012 ◽  
Vol 66 (12) ◽  
pp. 2505-2516 ◽  
Author(s):  
J. M. Ochando-Pulido ◽  
A. Martinez-Ferez
Keyword(s):  
Olive Oil ◽  
Large Scale ◽  
Wastewater Treatment Plants ◽  
Domestic Wastewater ◽  
Olive Mill Wastewater ◽  
Operating Conditions ◽  
Added Value ◽  
Wastewater Reclamation ◽  
Starting Point ◽  
Olive Mill

Direct disposal of the heavily polluted effluent from olive oil industry (olive mill wastewater, OMW) to the environment or to domestic wastewater treatment plants is actually prohibited in most countries, and conventional treatments are ineffective. Membranes are currently one of the most versatile technologies for environmental quality control. Notwithstanding, studies on OMW reclamation by membranes are still scarce, and fouling inhibition and prediction to improve large-scale membrane performance still remain unresolved. Consequently, adequately targeted pretreatment for the specific binomium membrane-feed, as well as optimized operating conditions for the proper membranes, is today's challenge to ensure threshold flux values. Several membrane materials, configurations and pore sizes have been elucidated, and also different pretreatments including sedimentation, centrifugation, biosorption, sieving, filtration and microfiltration, various types of flocculation as well as advance oxidation processes have been applied so far. Recovery of potential-value compounds, such as a variety of polyphenols highlighting oleuropein and hydroxytyrosol, has been attempted too. All this research should constitute the starting point to proceed with OMW purification beyond recycling for irrigation or depuration for sewer discharge, with the aim of complying with standards to reuse the effluent in the olive oil production process, together with cost-effective recovery of added-value compounds.

scholarly journals Exposure of Ceramics and Ceramic Matrix Composites in Simulated and Actual Combustor Environments

2000 ◽  
Vol 122 (2) ◽  
pp. 212-218 ◽  
Author(s):  
Karren L. More ◽  
Peter F. Tortorelli ◽  
Mattison K. Ferber ◽  
Larry R. Walker ◽  
James R. Keiser ◽  
...  
Keyword(s):  
Ceramic Matrix Composite ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Surface Damage ◽  
Operating Conditions ◽  
Matrix Composites ◽  
Long Term Stability ◽  
Recession Rates ◽  
Combustor Liner

A high-temperature, high-pressure, tube furnace has been used to evaluate the long term stability of different monolithic ceramic and ceramic matrix composite materials in a simulated combustor environment. All of the tests have been run at 150 psia, 1204°C, and 15 percent steam in incremental 500 h runs. The major advantage of this system is the high sample throughput; >20 samples can be exposed in each tube at the same time under similar exposure conditions. Microstructural evaluations of the samples were conducted after each 500 h exposure to characterize the extent of surface damage, to calculate surface recession rates, and to determine degradation mechanisms for the different materials. The validity of this exposure rig for simulating real combustor environments was established by comparing materials exposed in the test rig and combustor liner materials exposed for similar times in an actual gas turbine combustor under commercial operating conditions. [S0742-4795(00)02402-9]

Dynamic Parameters of Prestressed Hanging Systems

2021 ◽  
Vol 887 ◽  
pp. 698-705
Author(s):  
N.S. Razzokov ◽  
U.S. Akhmadiyorov
Keyword(s):  
Operating Conditions ◽  
Local Damage ◽  
Dynamic Parameters ◽  
Dynamic Effects ◽  
Static Loads ◽  
Long Span ◽  
Design Basis ◽  
Operational Safety ◽  
Properties Of Materials

The dynamic parameters of long-span prestressed one and two-belt hanging roofs, for which the seismic wavelengths are commensurate with the dimensions of the structure in plan, are considered. Calculated expressions have been obtained to determine the dynamic parameters for symmetric and skew-symmetric oscillations depending on the length of seismic waves.To ensure the operational safety of unique buildings and structures, we studied the change in the structural properties of materials from unfavorable operating conditions, long-term, beyond design-basis static loads, high-intensity dynamic effects, compliance of the support contours and the possibility of local damage and from the failure of cables of the structures under study.

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