Powder Spheroidization Using Induction Plasma Technology

2000 ◽  
Author(s):  
N.M. Dignard ◽  
M.I. Boulos
Keyword(s):  
Energy Efficiency ◽  
Maximum Energy ◽  
Operating Conditions ◽  
Side Reactions ◽  
Induction Plasma ◽  
Silica Alumina ◽  
Change In The Mean ◽  
The Individual ◽  
Semi Empirical ◽  
Objective Being

Abstract An experimental study of the spheroidization efficiency of induction plasma processes was completed. The main objective being to obtain models which could be subsequently used for the prediction of the spheroidization efficiency for various powders and plasma operating conditions. Silica, alumina, chromium oxide and zirconia powders were treated during the experimentation. For the plasma treatment of the powders the installation used had a maximum available power of 50 kW with an operating frequency of 3 MHz. Operating conditions were varied such to minimize side reactions and the evaporation of powders. The resulting powders did show the presence of cavities and a slight change in the mean diameters. The maximum energy efficiency based semi-empirical model did predict the spheroidization efficiency of the particles beyond a defined critical point known as the maximum energy efficiency point. For the model, the maximum energy efficiency is distinct for the individual powders but remain within a defined range which is reflected in the small variations in the Z constant.

Comparison of Energy Efficiency of the Redundant Actuation of Positioning Axes

2016 ◽  
Vol 821 ◽  
pp. 620-625
Author(s):  
Kamil Šubrt ◽  
Radek Knoflíček ◽  
Pavel Houška
Keyword(s):  
Energy Efficiency ◽  
Energy Consumption ◽  
Current Trend ◽  
Electricity Consumption ◽  
Operating Conditions ◽  
Redundant Actuation ◽  
Electrical Efficiency ◽  
Measurement Results ◽  
The Individual ◽  
Selection Of

Presently, production machines and mainly contemporary machining centers are subjected to ever increasing pressure to enhance energy efficiency, both from the side of customers and also in terms of legislative regulations. A selection of drives for the individual axes is primarily a compromise between achievable dynamics, precision and price. The electrical efficiency and energy consumption is not usually taken into consideration during the design of the axis. In this paper, the electricity consumption of single drive axis actuator and redundant actuation through two drives is compared under various operating conditions. The measurement results are used to assess the benefits of redundant actuation of positioning axes with emphasis on energy efficiency, which is consistent with the current trend of the so-called Ecodesign.

Reactions in Activated Peroxide Systems and their Influences on Bleaching Performance

2020 ◽  
Vol 17 ◽  
Author(s):  
Xiaoyan Wang ◽  
Jinmei Du ◽  
Changhai Xu
Keyword(s):  
Aqueous Solution ◽  
Hydrogen Peroxide ◽  
Energy Efficiency ◽  
Textile Industry ◽  
High Energy ◽  
Side Reactions ◽  
Competitive Reactions ◽  
High Energy Efficiency ◽  
Hydrolysis Of ◽  
Bleach Activators

Abstract:: Activated peroxide systems are formed by adding so-called bleach activators to aqueous solution of hydrogen peroxide, developed in the seventies of the last century for use in domestic laundry for their high energy efficiency and introduced at the beginning of the 21st century to the textile industry as an approach toward overcoming the extensive energy consumption in bleaching. In activated peroxide systems, bleach activators undergo perhydrolysis to generate more kinetically active peracids that enable bleaching under milder conditions while hydrolysis of bleach activators and decomposition of peracids may occur as side reactions to weaken the bleaching efficiency. This mini-review aims to summarize these competitive reactions in activated peroxide systems and their influence on bleaching performance.

scholarly journals Crystal growth of clathrate hydrate formed with H2 + CO2 mixed gas and tetrahydropyran

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Meku Maruyama ◽  
Riku Matsuura ◽  
Ryo Ohmura
Keyword(s):  
Crystal Growth ◽  
Synthesis Gas ◽  
Water System ◽  
Hydrate Formation ◽  
Growth Dynamics ◽  
Operating Conditions ◽  
Mixed Gas ◽  
Thermodynamic Conditions ◽  
The Individual ◽  
And Storage

AbstractHydrate-based gas separation technology is applicable to the CO2 capture and storage from synthesis gas mixture generated through gasification of fuel sources including biomass. This paper reports visual observations of crystal growth dynamics and crystal morphology of hydrate formed in the H2 + CO2 + tetrahydropyran (THP) + water system with a target for developing the hydrate-based CO2 separation process design. Experiments were conducted at a temperature range of 279.5–284.9 K under the pressure of 4.9–5.3 MPa. To simulate the synthesis gas, gas composition in the gas phase was maintained around H2:CO2 = 0.6:0.4 in mole fraction. Hydrate crystals were formed and extended along the THP/water interface. After the complete coverage of the interface to shape a polycrystalline shell, hydrate crystals continued to grow further into the bulk of liquid water. The individual crystals were identified as hexagonal, tetragonal and other polygonal-shaped formations. The crystal growth rate and the crystal size varied depending on thermodynamic conditions. Implications from the obtained results for the arrangement of operating conditions at the hydrate formation-, transportation-, and dissociation processes are discussed.

scholarly journals Micromagnetic Characterization of Operation-Induced Damage in Charpy Specimens of RPV Steels

2021 ◽  
Vol 11 (7) ◽  
pp. 2917
Author(s):  
Madalina Rabung ◽  
Melanie Kopp ◽  
Antal Gasparics ◽  
Gábor Vértesy ◽  
Ildikó Szenthe ◽  
...  
Keyword(s):  
Neutron Irradiation ◽  
Pressure Vessel ◽  
Operating Conditions ◽  
Magnetic Characteristics ◽  
Pressure Vessel Steel ◽  
Training Procedure ◽  
Vessel Steel ◽  
Before And After ◽  
The Individual ◽  
Magnetic Adaptive Testing

The embrittlement of two types of nuclear pressure vessel steel, 15Kh2NMFA and A508 Cl.2, was studied using two different methods of magnetic nondestructive testing: micromagnetic multiparameter microstructure and stress analysis (3MA-X8) and magnetic adaptive testing (MAT). The microstructure and mechanical properties of reactor pressure vessel (RPV) materials are modified due to neutron irradiation; this material degradation can be characterized using magnetic methods. For the first time, the progressive change in material properties due to neutron irradiation was investigated on the same specimens, before and after neutron irradiation. A correlation was found between magnetic characteristics and neutron-irradiation-induced damage, regardless of the type of material or the applied measurement technique. The results of the individual micromagnetic measurements proved their suitability for characterizing the degradation of RPV steel caused by simulated operating conditions. A calibration/training procedure was applied on the merged outcome of both testing methods, producing excellent results in predicting transition temperature, yield strength, and mechanical hardness for both materials.

scholarly journals Design of Molecular Water Oxidation Catalysts Stabilized by Ultrathin Inorganic Overlayers—Is Active Site Protection Necessary?

Inorganics ◽  
2018 ◽  
Vol 6 (4) ◽  
pp. 105 ◽  
Author(s):  
Laurent Sévery ◽  
Sebastian Siol ◽  
S. Tilley
Keyword(s):  
Water Oxidation ◽  
Atomic Layer ◽  
Deposition Process ◽  
Operating Conditions ◽  
Molecular Water ◽  
Side Reactions ◽  
Aqueous Environment ◽  
Oxidation Catalysts ◽  
Initial Onset ◽  
Anchoring Groups

Anchored molecular catalysts provide a good step towards bridging the gap between homogeneous and heterogeneous catalysis. However, applications in an aqueous environment pose a serious challenge to anchoring groups in terms of stability. Ultrathin overlayers embedding these catalysts on the surface using atomic layer deposition (ALD) are an elegant solution to tackle the anchoring group instability. The propensity of ALD precursors to react with water leads to the question whether molecules containing aqua ligands, such as most water oxidation complexes, can be protected without side reactions and deactivation during the deposition process. We synthesized two iridium and two ruthenium-based water oxidation catalysts, which contained an aqua ligand (Ir–OH2 and Ru–OH2) or a chloride (Ir–Cl and Ru–Cl) that served as a protecting group for the former. Using a ligand exchange reaction on the anchored and partially embedded Ru–Cl, the optimal overlayer thickness was determined to be 1.6 nm. An electrochemical test of the protected catalysts on meso-ITO showed different behaviors for the Ru and the Ir catalysts. The former showed no onset difference between protected and non-protected versions, but limited stability. Ir–Cl displayed excellent stability, whilst the unprotected catalyst Ir–OH2 showed a later initial onset. Self-regeneration of the catalytic activity of Ir–OH2 under operating conditions was observed. We propose chloride ligands as generally applicable protecting groups for catalysts that are to be stabilized on surfaces using ALD.

High-efficiency hybrid PV-TEG system with intelligent control to harvest maximum energy under various non-static operating conditions

2021 ◽  
pp. 128643
Author(s):  
Adeel Feroz Mirza ◽  
Majad Mansoor ◽  
Kamal Zerbakht ◽  
Muhammad Yaqoob Javed ◽  
Muhammad Hamza Zafar ◽  
...  
Keyword(s):  
Intelligent Control ◽  
High Efficiency ◽  
Maximum Energy ◽  
Operating Conditions

Reverse Engineering Using Close Range Photogrammetry for Additive Manufactured Reproduction of Egyptian Artefacts and Other Objets d’art

2014 ◽  
Author(s):  
John Kaufman ◽  
Allan E. W. Rennie ◽  
Morag Clement
Keyword(s):  
Laser Scanning ◽  
Computer Software ◽  
Operating Conditions ◽  
Digital Data ◽  
Image Capture ◽  
Processing Power ◽  
Single Lens ◽  
Close Range ◽  
Geometric Representations ◽  
Objective Being

Photogrammetry has been in use for over one hundred and fifty years. This research considers how digital image capture using a medium range Nikon Digital SLR camera, can be transformed into 3D virtual spatial images, and together with additive manufacturing (AM) technology, geometric representations of the original artefact can be fabricated. The research has focused on the use of photogrammetry as opposed to laser scanning (LS), investigating the shift from LS use to a Digital Single Lens Reflex (DSLR) camera exclusively. The basic photogrammetry equipment required is discussed, with the main objective being simplicity of execution for eventual realisation of physical products. As the processing power of computers has increased and become widely available, at affordable prices, software programs have improved, so it is now possible to digitally combine multi-view photographs, taken from 360°, into 3D virtual representational images. This has now led to the possibility of 3D images being created without LS intervention. Two methods of digital data capture are employed and discussed, in acquiring up to 130 digital data images, taken from different angles using the DSLR camera together with the specific operating conditions in which to photograph the objects. Three case studies are documented, the first, a modern clay sculpture, whilst the other two are 3000 year old Egyptian clay artefacts and the objects were recreated using AM technology. It has been shown that with the use of a standard DSLR camera and computer software, 2D images can be converted into 3D virtual video replicas as well as solid, geometric representation of the originals.

Hydrogen Production via Catalytic Autothermal Reforming of Desulfurized Jet-A Fuel

2016 ◽  
Author(s):  
Shuyang Zhang ◽  
Xiaoxin Wang ◽  
Peiwen Li
Keyword(s):  
Energy Efficiency ◽  
Hydrogen Production ◽  
Hydrogen Storage ◽  
Coke Formation ◽  
Autothermal Reforming ◽  
Operating Conditions ◽  
Hydrogen Yield ◽  
Fuel Conversion ◽  
Optimal Operating ◽  
Reaction Equilibrium

On-board hydrogen production via catalytic autothermal reforming is beneficial to vehicles using fuel cells because it eliminates the challenges of hydrogen storage. As the primary fuel for both civilian and military air flight application, Jet-A fuel (after desulfurization) was reformed for making hydrogen-rich fuels in this study using an in-house-made Rh/NiO/K-La-Ce-Al-OX ATR catalyst under various operating conditions. Based on the preliminary thermodynamic analysis of reaction equilibrium, important parameters such as ratios of H2O/C and O2/C were selected, in the range of 1.1–2.5 and 0.5–1.0, respectively. The optimal operating conditions were experimentally obtained at the reactor’s temperature of 696.2 °C, which gave H2O/C = 2.5 and O2/C = 0.5, and the obtained fuel conversion percentage, hydrogen yield (can be large than 1 from definition), and energy efficiency were 88.66%, 143.84%, and 64.74%, respectively. In addition, a discussion of the concentration variation of CO and CO2 at different H2O/C, as well as the analysis of fuel conversion profile, leads to the finding of effective approaches for suppression of coke formation.

Driveline Configuration and Terrain Effect on Slippage and Efficiency of a 6×6/6×4 Truck

2013 ◽  
Author(s):  
Vladimir V. Vantsevich ◽  
Dennis Murphy ◽  
Gianantonio Bortolin ◽  
Blair Farley ◽  
Gabriel Judd
Keyword(s):  
Energy Efficiency ◽  
Analytical Method ◽  
Power Distribution ◽  
Operating Conditions ◽  
Surface Type ◽  
Vehicle Efficiency ◽  
Terrain Effect ◽  
Truck Transportation

The power distribution between driving wheels has been shown to have a significant impact on vehicle energy efficiency, but there has only been limited research in this area. As shown in this paper, the wheel power distribution is largely dependent on the power dividing units (PDUs) which split/vector power between the driving wheels. The performance of a particular driveline system will also depend largely on the terrain conditions the vehicle encounters. This paper presents an analysis of PDU configurations in 6×6/6×4 terrain trucks. The vehicle efficiency is evaluated in a wide variety of typical operating conditions including varying surface types, speeds and accelerations, and slope conditions. An analytical method is presented which can be used to determine the tire circumferential forces and slippages. Finally, an analysis of the effects of the driveline configuration, terrain, and surface type on truck transportation efficiency is presented for three PDU combinations.

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