MICROSCOPIC EXAMINATION OF METALS
In this experiment, our aim is examining the microstructure of metals. By studying microscopic structures of metals, we determine which material fits best to a given application. We used the most common method, optical technique, to examine the microstructure.
We used a small specimen cut from the metal to be examined. To be able to see the structure clearly, we first cleaned and polished the specimen. First we start polishing with emery paper no: 1 and some finer grades. One should be careful about the coarse abrasive particles and striations from them. Cleaning and rotating the specimen 90° during the transfer can prevent these. The next step is polishing, yet washing the sample before polishing gives a more successful result. Finally, we polished the specimen on a rotating cloth covered with an effective abrasive like Al2O3-Water suspension. We kept polishing until we obtained a mirror like face.
After we finished polishing, the crystalline structure of the specimen, any cracks, seams, non-metallic inclusions and inhomogenities, could be revealed. Before start etching we first applied mounting process. In this step we used a matched die set. We placed our sample into the die set in the way that the rough face of the specimen was the lower surface and the polished face looked upward. We filled the die cavity with Bakelite and then we transferred our die to a mounpress. Mounting not only protects our sample but also by making its base flat and stable helps us while we are examining the sample under the microscope.
In etching process, depending upon chemical composition, energy content and grain orientation, we determine the grain boundaries and the presence of chemically different phases. To reveal these micro structural details of the polished mount we used an etchant like 1% Nital.
Released in 1949, Pinky regales the tale of Patricia “Pinky” Johnson (played by Jeanne Crain) and her struggles in Mississippi during the Jim Crow era. Pinky, a certified nurse from up North, relocates back to Mississippi because she is afraid of being discovered passing, or having black blood but being so light skinned that one can pass for white. However, she is in love with Dr. Thomas Adams, played by William Lundigan, a white man whom she met while she was living in Boston for nursing school. Upon her return to Mississippi, her illiterate grandmother Aunt Dicey takes care of her, but eventually asks her to take care of her dying, white friend, Miss Em. Despite her efforts to go back to the North in order to escape from the racial barriers of Mississippi, Pinky reluctantly agrees to
In order to perform the micro hardness test on the samples, they were first roughly polished using belt grinder. Then they were polished with the Emery papers as described in previous descriptions so as to obtain flat surfaces and to avoid anomalies in the results.
Alloys in the ornament manufacturing are a general use of gold. Because of it is...
He claims that knowledge is the most essential mental state which therefore cannot be reduced to basic mental states such as belief and justification. This argument is supported by the idea that knowledge is the basis of what we perceive. This is validated by the fact that false knowledge cannot exist, whereas false belief can. Williamson provides an example of this through the idea of the Earth being flat. Those who believed the Earth was flat had believed falsely that they knew the Earth was flat. False knowledge cannot exist because it would require the Earth to be
Pediatric nurses do a lot of the same tasks as a regular nurse. They draw blood, check vital signs, can perform physical examinations, and order diagnostic tests. However, the job of a pediatric nurse goes beyond regular nurses. They must have a caring relationship not only with the patient they are tending to, but also the patient’s family. Parents usually prefer a pediatric nurse over a regular nurse due to the caring relationship they carry. This is well known by the nurses as the caring process. During this process the nurse must help the child and the child’s family step by step with anything they may need at the time. The pediatric nurse provides support, care, and information on how to prevent future problems. Pediatric nursing can be defined as “the practice of nursing with children, youth, and their families across the health continuum, including health promotion, illness management, and health restoration" (Barnsteiner et al). Therefore, you can see from that statement alone there is more than one job to be done by a pediatric nurse. A pediatric nurse can see anywhere from 80 to 100 children a day. They take appointments, walk-ins, and sometimes make home visits. Only when the pediatric nurse finds an abnormality will they refer and send the child t...
...take classes such as general biology, organic and inorganic chemistry, physics, and anatomy (Guerin interview). By graduating from an approved dental school and by passing a state board examination, required to qualify for a license in all states, sdentists prepare themselves to begin the practice of dentistry. The general practice of dentistry revolves around families, and working with the dental needs of children. Considering the number one medical problem of children is cavities, dental practice must include working with little children. Children may be eating too many sweets; they may not be flossing and brushing their teeth. Either way, dentistry as a profession must respond to their needs. Several hundred years ago, dentistry was basic repair work. Now that dentistry s a well-known and well-respected profession, most people demand its services. Although practicing dentistry is very complex, the practice of dentistry is in high demand. For many high school students with high goals and a good work ethic, the field of dentistry offers exceptional incentives in a wide choice of specialties, excellent economic opportunities, and the self gratification given y the patient’s smile.
Throughout the years, I've learned to accept the fact that going to the dentist is as bad as it seems. In other words, no kid has ever liked going to the dentist, for the fact being that all they seem to do is dig through our mouths and jab at our gums. At one point or another, everyone is required to go to the dentist for either a filling, cavity, or just simply a cleaning, but that wasn't the case for me. I had to get my braces on. Doesn't sound as bad as it truly is but two years of dealing with metal in your mouth isn't my idea of “a walk in the park”. Not only is getting braces on a bad thing for me but the fact that it was early in the morning so I was tired and that fact that I felt like I was growing old just waiting for the dentist
The first dental visit should occur within six months after the presence of the first tooth or by a child’s first birthday. The first visit to the dentist should be enjoyable. Of course parents should refrain from any negative comments about the dentist around the child. The dentist and staff will explain the procedure that they will receive. It is important that you choose the right dentists who specialize in pediatric dental care.
The contraction moulding method can be used to process an acrylic denture base. In this method, bite blocks are fabricated in the lab and sent to the clinic for patient trial. These are then received from the clinic and teeth are mounted onto the bite blocks. The wax is eliminated and teeth are pressurized and attached onto a gypsum mould. (McCabe and Walls. 2008.) Sodium alginate is applied onto the mould to act as a separator to prevent any monomer from the acrylic base seeping into the base and the mould. Acrylic PMMA is applied onto the mould and either heat-cured or auto-polymerized. Both of these curing methods form the...
Pediatric Dentistry is a superb fit for me since I enjoy working with children. Dentists diagnose and treat problems with patients’ teeth, gums, and related parts
Fear in the dental environment might also a result of what ideas about dental treatment was taught on a child. There are situations that relatives used the scariest scene on a dental environment to make the child follow directions such as they should brush their teeth in order not to see a dentist for tooth extraction. Tooth extraction is always introduced as painful experience because of the needle infiltration part. Child’s negative responses such crying, tantrums, and refusal to treatment can cause cancellation and postponement of the following dental visits. Anxiety or fearfulness affects a child’s behavior. To a large extent, it determines the success of a dental appointment. Negative response on the stimuli of pain, pressure, and fear on a dental environment can change into a positive response of cooperation and willingness to be treated when the anxiety of the child will be managed through different strategies. Over the years, anxiety management has meant different things to different people. Anxiety management is the means by which the dental health team effectively and efficiently performs treatment for a child and, at the same time, instills a positive dental
Children are often scared of the dentist, it can be very hard to overcome their fear. It is best if as a parent if you briefly explain to your child what is going to happen , that they have no reason to be scared. Do not promise a reward to your child for going to the dentist. Explain to you...
Amalgams restoration could also protect the margin of teeth, preventing leakage of a filling or help prevent recurrent decay when done properly. The process of placing an amalgam was something like this, After the patient has been numbed and tooth has been isolated and the dentist has prepped the tooth cavity, patient is ready to begin his dental amalgam treatment. The process before placing a dental amalgam is called trituration. One must first mix the metal alloy which is in powder form with mercury liquid, both of these elements come in a capsule. This capsule is then being triturated on the amalgamator and takes form of a perfect dough ball, if over triturated it will crumble, or if under triturated it will look
When looking for a dentist the first order of business is to decide what type of dentistry you wish to participate in: pediatric dentistry, general dentistry, or family dentistry. Pediatric dentistry is obviously the dental care of children. General dentistry generally allows patients of more mature ages to visit. Unlike general dentistry, family dentistry specializes in the routine and preventative care of all age groups as well as the oral family history of patients. Like it says in the name, family dentistry focuses on the dental care of your entire family.
Metals possess many unique fundamental properties that make them an ideal material for use in a diverse range of applications. Many common place things know today are made from metals; bridges, utensils, vehicles of all modes of transport, contain some form of metal or metallic compound. Properties such as high tensile strength, high fracture toughness, malleability and availability are just some of the many advantages associated with metals. Metals, accompanied by their many compounds and alloys, similar properties, high and low corrosion levels, and affects, whether negative or positive, are a grand force to be reckoned with.