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EE&C Policy Considerations
Published in Swapan Kumar Dutta, Jitendra Saxena, Binoy Krishna Choudhury, Energy Efficiency and Conservation in Metal Industries, 2023
In “Explainer: These six metals are key to a low-carbon future” [3], it has been pointed out that in order to meet the Paris Agreement’s goals of limiting global warming to “well below 2°C” and to strive for 1.5°C, fast adaptation of low-carbon technologies for the six more important metals—viz. aluminum, silver, steel, nickel, lead and zinc, along with copper, lithium, nickel, cobalt and neodymium (rare Earth elements)—will be needed.
Modern Abrasive Processes
Published in Hassan El-Hofy, Fundamentals of Machining Processes, 2018
Tools: Tool tips must have high wear resistance and high fatigue strength. For machining glass and tungsten carbide, copper and chromium silver steel tools are recommended. Silver and chromium nickel steel are used for machining sintered carbides. During USM, tools are fed toward, and held against, the workpiece by means of a static pressure that has to overcome the cutting resistance at the interface of the tool and workpiece.
Handling engineering information
Published in Roger Timings, Engineering Fundamentals, 2007
Keep alert for errors in the information given. Suppose you have made several batches of a component from stainless steel and suddenly the works order form specifies silver steel. Is this a genuine change or a clerical error? So, the manager has signed it, but he is a very busy person and he may have missed the error. Therefore check with your supervisor before starting the job. Better to be sure than sorry.
Review on tools and tool wear in EDM
Published in Machining Science and Technology, 2021
Deepak Sharma, Somashekhar S. Hiremath
Electric discharge machining (EDM) is acknowledged as a most encouraging nontraditional manufacturing process in terms of precision and size. It is an alternate machining process typically used in the machining of electrically conductive materials. The schematic diagram of the EDM setup is shown in Figure 1. It consists of a workpiece electrode (anode) and tool electrode (cathode), which are connected to the DC power supply, mainly Resistor–Capacitor (RC) circuit. The other types of pulse generator circuits that can be used in EDM are transistor, rotary impulse, vacuum tube, and single-pole-dual-flow-switch type (Kunieda et al., 2005). Tool and workpiece are submerged in a dielectric fluid with a small gap among them, known as a spark gap. The spark gap is maintained by the tool feed mechanism, such as stepper motor, servo motor, solenoid control, inch-worm, piezo-actuator, and electromagnetic actuator. Aluminum, brass, ceramics, graphite, semiconductors, silver, steel, superalloys are the generally used tool material in EDM. The most commonly used dielectrics are de-ionized water, kerosene, paraffin, and transformer oil. The operating parameters of EDM are divided into two types electrical and non-electrical. Electrical parameters are peak current, open-circuit voltage, duty cycle, pulse frequency, and pulse on/off time. The non-electrical parameters are dielectric flushing pressure, dielectric fluid, tool rotation, tool feed, and tool vibration.
Study of the addition of Gabiroba leaves extract in the biodiesel oxidation reaction in the presence of metal ions
Published in Biofuels, 2023
Marco A. J. Clemente, Gustavo G. Marcheafave, Isadora G. Branco, Edmilson Antônio Canesin, Ana Carolina G. Mantovani, Letícia T. Chendynski, Karina B. Angilelli, Dionisio Borsato
Furthermore, it was possible to observe the reduction of the antioxidant activity of the Gabiroba leaves extract in the presence of Fe3+ ions. When this ion was added to biodiesel, in the presence of the extract, the induction period was 1.83 h, much lower when compared to the biodiesel samples with the metals Fe2+ (12.90 h) and Cu2+ (11 .69 h) containing the extract. Chendynski et al. [12], showed similar behavior when they studied the oxidative stability of biodiesel containing blackberry extract in the presence of silver steel.
Measuring ultrafine aerosols by direct photoionization and charge capture in continuous flow
Published in Aerosol Science and Technology, 2018
Robert T. Nishida, Adam M. Boies, Simone Hochgreb
The experimental photoionization chamber provides a volume in which aerosol particles are irradiated with UV light and subject to an electric field between two electrodes while in continuous flow. The sample aerosol flows from a sample inlet at the side of a cylindrical chamber, through the volume between the two electrodes, and through a sample outlet at the side of the chamber as seen in Figure 2. The first electrode is a 200 mm long aluminum cylinder of 25 mm diameter. A concentrically located silver steel rod (functioning as the second electrode) of 200 mm in length and 1.5 mm in diameter is mounted at the end of the photoionization chamber nearest the outlet, extending co-axially along the entire length of the photoionization chamber and electrically isolated with PTFE. An UV-extended fused silica optical window of 25 mm diameter and 3 mm thickness makes up one circular side of the cylindrical chamber. A 3 W UV lamp (Model Mini3W-52ozon, Dinies Technologies GmbH, Germany) is located externally, 20 mm from the window. The UV source and window are located nearest the sample inlet such that the flow direction is away from the light source. The lamp outputs narrow lines of ultraviolet light with wavelengths of 185 nm and 254 nm. A high-pass UV filter was used to demonstrate that the 254 nm line yielded negligible photoelectric emission, therefore the 185 nm light was considered the dominant for particle photo-emission. A voltage is applied between the electrodes in series with the electrometer current measurement, both using a Keithley electrometer (Model 6517B, Keithley Instruments Inc., Cleveland, OH, USA). The photoionization chamber is enclosed in an electrically isolated, aluminium box which acts as a Faraday cage and is grounded with the electrometer triaxial measurement cable. The electrometer provides electrode current, ie, with an accuracy of ±3 fA. However, electrical noise from other sources increases the signal error. Flow through the photoionization chamber was sampled from the ejector diluter exhaust line by the aerosol electrometer (1.5 std L min− 1). The aerosol electrometer measures outlet current, io, using a particle filter in a Faraday cup electrometer with a noise level less than 1 fA at 1 s averaging time.