1] Abrasive Technique: Abrasive technique is the mechanical technique to make the surface ready for printing or bonding. It serves only to increase. It increases the surface area of the material by "roughening" the exposed areas prior to coating, printing or adhesive bonding. Mechanical abrasion can be achieved by dry blasting, wet blasting or hand/machine blasting. To remove particulates or residues, a sol vent wash usual l y follows mechanical abrasion. In many cases, the spent abrasive materials fall under the classification of hazardous substances and must be disposed of accordingly. 2] Liquid Cleaning: Liquid cleaning can be very useful for removing gross contamination. Fluid cleaning techniques for polymer surfaces fall into three main …show more content…
Hand wiping can be done with a variety of sol vents, combination of sol vents, or an aqueous solution of various chemicals. Hand wiping can result in inconsistencies in quality due to either human error or the redeposition of soils onto the surfaces being cleaned from contaminated rags used in the process. Surface treatment by solvent cleaning is most beneficial in those cases where swelling of the polymer surface, due to solvent absorption, results in a rougher morphology that can improve the adhesion of coatings without adversely affecting the substrate's mechanical properties. The process uses inexpensive equipment and works reasonably well in many cases such as in the surface preparation of molded polymer parts for subsequent paint adhesive, or coating application. Solvent treatment processes can be conducted through wiping, immersion, spraying, or vapor degreasing. Typically, high-vapor pressure organic solvents (alcohols, ketones, toluene, etc), chlorinated hydrocarbon solvents (eg, Freons, or 1,1,1-tri chloroethane) or low-vapor pressure organic solvents (terpenes, isoparaffins, lactates, esters, etc) are used in these processes. The major drawbacks of the technology are the environmental and process hazards associated with the use of large quantities of …show more content…
A low-frequency (typically 10-20 kHz) generator and step up transformer usually provide the high voltage to the electrode. In each half-cycle the applied voltage (20 kV peak) increases until it exceeds the threshold value for electrical breakdown of the air gap, causing the atoms and molecules to become ionized and creating an atmospheric plasma discharge. The voltage eventually peaks and falls below the conducting threshold. Each cycle consists of two such events involving current flow in each direction. In continuous operation the discharge appears to be a random series of faint sparks in a blue-purple glow (uv radiation). The point discharge generated across the pair of electrodes ionizes the gas present in the gap, which subsequently induces changes in the chemistry of the
Like all objects, clocks inevitably get dust and dirt on them. The type of cleaning solution used to clean clocks depends on the material the clock is made out of. Usually, liquid cleaning solutions are used because they are cheap, easy to store, and are easier to get into a clock's many nooks and crannies. Hydrocarbon A high-purity-hydrocarbon cleaner is a rinsing agent used after the clock and its internal parts have been cleaned. Hydrocarbons are organic compounds made out of hydrogen and carbon. The solution spreads as an even film and is designed to leave a stain-free surface. Hydrocarbon solutions are safe to use on materials that are sensitive to solvents that contain chlorine. Clock Cleaning Concentrate Solution When clocks are
This depends on the type of electrode that is being used. In some ESPs the discharge electrodes are tubes rather than plates in which case they are washed by a water stream. In case of the electrodes being plates, rapping is used to remove the dust layer on the electrode. It is a process in which dust particles are dislodged from the electrodes by sending mechanical impulses or vibrations through the electrodes which causes the dust layer to fall off as sheets and thus avoiding any re-entrainment. The removal of the layer is carried out when the thickness of the layer is between 0.3-0.5 in. The intensity and frequency of rapping depends upon the particle concentration in the flue
Biomechanics is the overall topic that will be discussed throughout the presentation, this incorporates a brief discussion about water resistance, propulsion and buoyancy. Under lifesaving, appropriate techniques and the choice of stroke for the Timed Tow will be analyzed and justified.
For serious accumulations of dirt or other materials or substances, a hose can be used to clear away the debris. Even notoriously difficult substances like oil will not stick to or stain the surfacing.
There are two types of lightning discharges. These are the CC ( cloud to cloud) and CG (cloud to ground). These two discharges consist of different subtypes of lightning. These types of lightning are spider, bead, and ribbon. And rocket lightning. Spider lightning is a long lasting discharge, which usually exist along the cloud base. The discharge is believed to be so long that it seems to crawl along the base of clouds, which is why the nickname for this ligh...
The first thing to consider is the process of cleaning and coating of the boards. This particular process involves the set-up of the machines, the loading of the boards, and the actual cleaning and coating of the said boards by the machines.
3. Etching: If the resist is placed in a developer solution after selective exposure to a light source, it will etch away one of the two regions (exposed or unexposed). Then another layer of material is deposited and the first layer selectively etched away as shown in the figure resulting in the required MEMS.
Blunt force trauma is defined as a traumatic event caused by the introduction of any blunt instrument forcefully, causing injury to the body or head. The Severity of injury is determined by various factors. It may be due to mechanical force such as compression, traction, torsion or shear. Impact of the injury and severity depends on object and movement of victim. Injuries occurred may be internal such as lacerations of internal tissues, organs, fractures of bones or may be external such as abrasion, avulsion, contusion and laceration (Pollak & Saukko, 2009). Severity also depends on anatomical site impacted for ex: Lacerations have irregular margin, hanging causes abrasions, contusions and hyoid bone fractures, Ocular hemorrhages in case of blunt trauma to eyes or Fracture of ribs when hit on chest by a blunt object (Ressel, Hetzel, & Ricci, 2016). Severity is also determined by the duration of time and amount of force applied. Nature of trauma is of importance in forensic medicine. It helps in
2. Clean the surface of a 20 cm strip of magnesium ribbon using steel wool
At this moment, millions of Americans are working, traveling, driving, walking, shopping and driving, with so much activity in a person’s everyday life its no wonder accidents have become inevitable. Many accidents can be severe and life altering or even result in death, but the fact that accidents are fairly familiar does not reduce from the confusion and pain that can result when an injury or accident happens to you or a loved one. This is especially true when any harm could have been prevented if others had not acted inconsiderately. Personal injury can be psychological or physical but, to be considered unlawful, it must happen due to the negligence or unreasonably unsafe actions of your company, your physician, or some other person or corporation who owes you a duty of ordinary care.
(Bushong, 2013, p. 405). This phenomenon of electron emission following light stimulation is called photoemission. The emission of just one electron through photoemission is dependent upon numerous light photons. The amount of electrons produced by the photocathode is directly proportional to how much light reaches it from the input phosphor, which is directly proportional to the intensity of the initial x-ray beam. These electrons will be accelerated to the anode where they will pass through a small hole to the output phosphor.
3. Wipe around the edges of the sink and the faucet. Scrub any stuck-on particles.
The electrostatic precipitator (ESP) is a machine used in factories, to clean out the waste solid particle, for example ash from the exhaust gas, allowing clean exhaust gas exit through the chimney. The electrostatic precipitator functions by using first allow the exhaust gas with the waste solid particles pass through the Nozzle as shown in the diagram below. Then the exhaust gas passes through inlet gas distribution, which evenly distributes the gas as shown below in a turquoise color, and starts going through the Discharge electrodes and the collector plates, which is shown in the diagram red and blue respectively. The discharge electrodes, which are powered by high voltage direct current, ionize the gas along with the other solid waste particles negatively. The collector plates are also charged with high voltage electricity, but it is positively charged, therefore attracting the negatively charged solid particle, because oppositely charged particles attract. This allows the clean exhaust gas pass through the other end, while the solid waste particles are trapped in the collector plates. Eventually when there are enough solid waste particles collected on the collector plates, the collect plates shakes off the collected waste, where it drops to the bottom of the shaft as shown in the diagram as “Hopper”.
?Robotics will boost quality and transfer efficiency levels.? Coatings (Jul.-Aug. 1991): 66 InfoTrac. Online. Nov. 2002. .
I want you to think back to what might be the greatest invention ever. Dependant upon how well you know your history you could possibly say the wheel, the car, the airplane, the television, the autonomous robot. All of these are great ideas that have different eras in history, but they all have something in common, these creations were all invented by engineers. Do not get the misconception that engineers have been around since the dawn of time but the concept of engineering itself has. Those great revolutionaries all had ideas and solved problems which are still qualities that engineers of this day and age use. Webster defines engineering as, “the work of designing and creating large structures or new products or systems by using scientific methods.” Those people created new products so they would today be considered engineers, but they are slightly different. What makes them different is the field that they would be considered a part of. The broadest one of the oldest forms is mechanical engineering, which is my future profession.