scholarly journals An electrochemical engineering assessment of the operational conditions and constraints for solar-driven water-splitting systems at near-neutral pH

2015 ◽  
Vol 8 (9) ◽  
pp. 2760-2767 ◽  
Author(s):  
Meenesh R. Singh ◽  
Kimberly Papadantonakis ◽  
Chengxiang Xiang ◽  
Nathan S. Lewis
Keyword(s):  
Water Splitting ◽  
Operating Conditions ◽  
Electrochemical Engineering ◽  
Efficient Operation ◽  
Operational Conditions ◽  
Neutral Ph

Identified operating conditions and constraints for efficient operation of solar-driven water-splitting systems at near-neutral pH.

scholarly journals Evaluation of flow schemes for near-neutral pH electrolytes in solar-fuel generators

2017 ◽  
Vol 1 (3) ◽  
pp. 458-466 ◽  
Author(s):  
Meenesh R. Singh ◽  
Chengxiang Xiang ◽  
Nathan S. Lewis
Keyword(s):  
Design Principles ◽  
Operating Conditions ◽  
Solar Fuel ◽  
Efficient Operation ◽  
Neutral Ph ◽  
Active Flow

Operating conditions and design principles for the efficient operation of solar-fuel generators with active flow of near-neutral pH electrolytes.

"Recent Patents on the Triboelectrostatic Separation of Fly Ash"

2019 ◽  
Vol 13 ◽  
Author(s):  
Haisheng Li ◽  
Wenping Wang ◽  
Yinghua Chen ◽  
Xinxi Zhang ◽  
Chaoyong Li
Keyword(s):  
Fly Ash ◽  
Power Plants ◽  
High Efficiency ◽  
Separation Efficiency ◽  
High Reliability ◽  
Operating Conditions ◽  
Security Requirements ◽  
Unburned Carbon ◽  
Efficient Operation ◽  
Triboelectrostatic Separation

Background: The fly ash produced by coal-fired power plants is an industrial waste. The environmental pollution problems caused by fly ash have been widely of public environmental concern. As a waste of recoverable resources, it can be used in the field of building materials, agricultural fertilizers, environmental materials, new materials, etc. Unburned carbon content in fly ash has an influence on the performance of resource reuse products. Therefore, it is the key to remove unburned carbon from fly ash. As a physical method, triboelectrostatic separation technology has been widely used because of obvious advantages, such as high-efficiency, simple process, high reliability, without water resources consumption and secondary pollution. Objective: The related patents of fly ash triboelectrostatic separation had been reviewed. The structural characteristics and working principle of these patents are analyzed in detail. The results can provide some meaningful references for the improvement of separation efficiency and optimal design. Methods: Based on the comparative analysis for the latest patents related to fly ash triboelectrostatic separation, the future development is presented. Results: The patents focused on the charging efficiency and separation efficiency. Studies show that remarkable improvements have been achieved for the fly ash triboelectrostatic separation. Some patents have been used in industrial production. Conclusion: According to the current technology status, the researches related to process optimization and anti-interference ability will be beneficial to overcome the influence of operating conditions and complex environment, and meet system security requirements. The intelligent control can not only ensure the process continuity and stability, but also realize the efficient operation and management automatically. Meanwhile, the researchers should pay more attention to the resource utilization of fly ash processed by triboelectrostatic separation.

scholarly journals Performance analysis of the working surface of the rails from test batches on the Test Loop of JSC “VNIIZhT”

2018 ◽  
Vol 77 (3) ◽  
pp. 141-148
Author(s):  
M. Yu. Khvostik ◽  
I. V. Khromov ◽  
O. A. Bykova ◽  
G. A. Beresten’
Keyword(s):  
Wear Resistance ◽  
Operating Time ◽  
Operating Conditions ◽  
Continuous Change ◽  
Wear Area ◽  
Railway Network ◽  
Operational Conditions ◽  
Rolling Surface ◽  
Test Loop ◽  
The Impact

The monitoring of railway rails damage on the railway network of the JSC “Russian Railways” as well as operational and polygon tests are conducted with the purpose of assessing the impact of operating conditions on the intensity of rails damage, obtaining initial data for forecasting rails failures. The increased intensity of rails wear on sites with a complex plan and profile leads to the fact that with a continuous change from the track, rails which have an underutilized service life of more than 20 % are retrieved. Polygon tests on the Test Loop of the JSC “VNIIZhT” near the Scherbinka station can provide the repeatability and reliability of the results, comparative tests are carried out under identical conditions and their duration is several times less than when tested at experimental sites under operational conditions. The results of the polygon tests of new differentially heat-strengthened rails did not reveal any advantages in the wear resistance of special purposed rails (laid in the recommended radius of the curve for its application) when comparing the rails of domestic manufacturers. Metal shelling out on the rolling surface of rails is the main reason for the removal of rails from test batches. The origin and development of defects of this kind is due to both violations of the technology of manufacturing rails, and because of violations of the current maintenance of the track. The metal stock in the area of the rail head of R65 type due to the increase in its dimensions positively affects the extension of the lifetime of the rails, reducing the cost of the life cycle and the rail itself, and the design of the track as a whole. When carrying out a separate study in order to obtain results characterizing the stability of high-quality rails to contact fatigue damage, it is advisable to optimize the conditions of the polygon tests, bringing them closer to operational ones. When forming the test results, it is necessary to expand the list of criteria for assessing the wear resistance of rails, supplementing it with the size of the wear area at the time of a certain operating time of the tonnage, with the introduction of this criterion into the appropriate methods for the polygon (operational) tests.

scholarly journals Inside Cover: WO3@α-Fe2O3Heterojunction Arrays with Improved Photoelectrochemical Behavior for Neutral pH Water Splitting (ChemCatChem 17/2016)

ChemCatChem ◽  
2016 ◽  
Vol 8 (17) ◽  
pp. 2734-2734
Author(s):  
Yuan Li ◽  
Lihan Zhang ◽  
Ruirui Liu ◽  
Zhen Cao ◽  
Xiaoming Sun ◽  
...  
Keyword(s):  
Water Splitting ◽  
Neutral Ph

Wavelet Transform Modulus Maxima Decay Lines

2015 ◽  
pp. 48-68
Author(s):  
Andreas Kyprianou ◽  
Andreas Tjirkallis
Keyword(s):  
Experimental Data ◽  
Wavelet Transform ◽  
Damage Detection ◽  
Environmental Conditions ◽  
Simulated Data ◽  
Random Excitation ◽  
Operating Conditions ◽  
Structural Behaviour ◽  
Operational Conditions ◽  
Three Degree Of Freedom

An important task in structural health monitoring (SHM) is that of damage detection under varying environmental and operational conditions. Structures, under varying environmental conditions, change their mass, elasticity and damping properties whereas changing operational conditions cause changes to excitations. A damage detection methodology implemented in these circumstances faces serious challenges since changes to structural behaviour imparted by environmental or operational conditions could be wrongly attributed to damage. The part of a damage detection decision algorithm that removes environmental and operational effects is called normalization. In this chapter a normalization methodology that is based on the similarity between continuous wavelet transform maxima decay lines is presented. This methodology is implemented on both simulated and experimental data. Simulated data were obtained from a three degree of freedom system. Varying environmental conditions were simulated by temperature dependent stiffness parameters and operating conditions by changing the colour of random excitation. Experimental data were obtained from damaged cantilever beams that were subjected to random excitations of different colour and varying temperatures.

scholarly journals Continuous electrochemical reactor improved by the addition of Moringa oleífera lam extract: optimization of operational conditions for Blue 5G dye removal

2019 ◽  
Vol 14 (3) ◽  
pp. 1
Author(s):  
Bruna Souza dos Santos ◽  
Eduardo Eyng ◽  
Paulo Rodrigo Stival Bittencourt ◽  
Laercio Mantovani Frare ◽  
Éder Lisandro de Moraes Flores ◽  
...  
Keyword(s):  
Retention Time ◽  
Moringa Oleifera ◽  
Hydraulic Retention Time ◽  
Operating Conditions ◽  
Current Intensity ◽  
Quadratic Model ◽  
Residual Concentration ◽  
Natural Coagulant ◽  
Operational Conditions ◽  
Moringa Oleifera Lam

Wastewaters from textile industries are known for their difficulty to treat, several alternative technologies are applied for their treatment. In this context, the study examined a hybrid treatment system, composed of electrocoagulation combined with a natural coagulant (extract of Moringa oleífera lam seeds) to remove reactive dye Blue 5G aqueous solutions. The work evaluated the use of milder operating conditions to improve the efficiency of treatment, with reduced demands for electrical power and coagulant.  The following factors were evaluated: electric current intensity, natural coagulant concentration and hydraulic retention time. A quadratic model was adjusted and validated at a 5% significance level. The overall optimization resulted in conditions of 0.28 A for electrical current intensity, 1000.00 mg L-1 of aqueous extract of Moringa oleífera lam and 5 min for hydraulic retention time. While operating under optimal conditions, the removal of 71.38% of color and 5.22 mg L-1 of iron residual concentration was achieved.

scholarly journals In Situ EPR Characterization of a Cobalt Oxide Water Oxidation Catalyst at Neutral pH

Catalysts ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 926 ◽  
Author(s):  
Yury Kutin ◽  
Nicholas Cox ◽  
Wolfgang Lubitz ◽  
Alexander Schnegg ◽  
Olaf Rüdiger
Keyword(s):  
Cobalt Oxide ◽  
Water Oxidation ◽  
Large Scale ◽  
Low Cost ◽  
Operating Conditions ◽  
Oxidation Catalyst ◽  
O2 Evolution ◽  
Ligand Field ◽  
Neutral Ph

Here we report an in situ electron paramagnetic resonance (EPR) study of a low-cost, high-stability cobalt oxide electrodeposited material (Co-Pi) that oxidizes water at neutral pH and low over-potential, representing a promising system for future large-scale water splitting applications. Using CW X-band EPR we can follow the film formation from a Co(NO3)2 solution in phosphate buffer and quantify Co uptake into the catalytic film. As deposited, the film shows predominantly a Co(II) EPR signal, which converts into a Co(IV) signal as the electrode potential is increased. A purpose-built spectroelectrochemical cell allowed us to quantify the extent of Co(II) to Co(IV) conversion as a function of potential bias under operating conditions. Consistent with its role as an intermediate, Co(IV) is formed at potentials commensurate with electrocatalytic O2 evolution (+1.2 V, vs. SHE). The EPR resonance position of the Co(IV) species shifts to higher fields as the potential is increased above 1.2 V. Such a shift of the Co(IV) signal may be assigned to changes in the local Co structure, displaying a more distorted ligand field or more ligand radical character, suggesting it is this subset of sites that represents the catalytically ‘active’ component. The described spectroelectrochemical approach provides new information on catalyst function and reaction pathways of water oxidation.

A Human Reliability Analysis to Crankshaft Overhauling in Dry-Docking of a General Cargo Ship

2020 ◽  
pp. 147509022094833
Author(s):  
Samet Bicen ◽  
Cagatay Kandemir ◽  
Metin Celik
Keyword(s):  
Reliability Analysis ◽  
Human Error ◽  
Task Type ◽  
Operating Conditions ◽  
Human Reliability ◽  
Human Reliability Analysis ◽  
Operational Conditions ◽  
Safety Issues ◽  
Immediate Recovery ◽  
General Cargo

This study conducts a practical application of shipboard operation human reliability analysis (SOHRA) to a crankshaft overhauling operation of a general cargo ship at dry-docking period. The SOHRA approach includes error producing condition (EPC) and general task type (GTT) parameters to consistently calculate the human error probability (HEP) values of operation steps. In this case, a comprehensive overhauling of main engine was planned at shipyard since the ship has experienced a catastrophic failure. An onboard survey to ship engine room is conducted to monitor the operational conditions. The targeted operation, involves disassembly, maintenance, and reassembly stages, is monitored based on 39 sub-tasks. According to the initial findings, immediate recovery actions are suggested to eliminate critical safety issues in a timely manner. Moreover, an extended discussion through long-term safety recommendations are also provided. The results revealed from case study illustrates that HEP values in maintenance operations are sensitive to ship operating conditions. The proposed approach is found very useful by company executives to support ship technical superintendents in critical operation monitoring. The further study is considered to develop mobile application of SOHRA specific to maintenance operations onboard ships.

Applicability of Pump Models for Varying Operational Conditions

2003 ◽  
Author(s):  
Heikki O. J. Kauranne ◽  
Jyrki T. Kajaste ◽  
Asko U. Ellman ◽  
Matti T. Pietola
Keyword(s):  
Rotational Speed ◽  
Operating Conditions ◽  
Fluid Temperature ◽  
Limited Information ◽  
Operational Conditions ◽  
Axial Piston Pumps ◽  
Pump Construction ◽  
Temperature And Pressure ◽  
Axial Piston ◽  
Type Pressure

It is commonly known that the characteristics of a fluid power pump depend on pump type, pressure, rotational speed and displacement. But in addition to these, also all the other parameters or factors associated with the operating conditions may have a significant effect on the characteristics. The most important of these are the pump construction and size, operating point temperature and the characteristics of the oil, which also depend on temperature and pressure. The aim of this study is to show the effects that the varying operational conditions have on the characteristics of a axial piston pump, to compare the measured characteristics with other published characteristics of axial piston pumps and to study the capability of pump models to represent these characteristics. The results include information of the effects of fluid temperature, type of fluid and the setting value of the displacement on the pump characteristics along with the effects of pressure and rotational speed. The sensitivity of the pump to each of the parameters is discussed. The effect of limited information of pump characteristics on the reliability of simulation results is studied using the Schlo¨sser models.

Combining Speed Control Function and Wye Passage in a Long Subsea Gas Line: A Case Study

2014 ◽  
Author(s):  
Hubert Lindner ◽  
Hans van Remmerden ◽  
Amit Shamgar
Keyword(s):  
Wall Thickness ◽  
Control Function ◽  
Operating Conditions ◽  
Single Individual ◽  
Individual Parameter ◽  
Operational Conditions ◽  
Battery Lifetime ◽  
Pipeline Inspection ◽  
Real Challenge

Challenging conditions for pipeline inspection can be caused by several different parameters and conditions (length, diameter changes, installations and operating conditions). Very often the real challenge is resulting from a combination of these influencing parameters. For example, a very long pipeline becomes particularly critical for battery lifetime if the flow rate is low. Each single individual parameter does not necessarily constitute such challenge. Some basic examples and a particular combination of pipeline parameters and operational conditions are presented in this article. The crucial parameters of the regarded pipeline are: 36″, about 700 km length, high wall thickness, high pressure and flow rates and a subsea wye piece. Some of these requirements are already demanding for former inspection tools. But the complex interaction of the features increases the challenge for the tool design significantly. Particularly the combination of high flow, high wall thickness and the wye piece passage required special attention. The article describes the pipeline properties and run conditions and the consequences for the entire cleaning and inspection program. Notably the interactions of the parameters regarding the MFL inspection are highlighted and the resulting tool concept is presented as well as the run results.

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