Friday, March 20, 2020

Memory Recall and Recognition for a Common Object

Memory Recall and Recognition for a Common Object -Abstract-The aim of this of this study was to investigate the accuracy of long term memory for a common object and more precisely to examine the differences between memory recognition and recall. Six participants took part in the experiment, three were assigned to the recognition task and three to the recall. The recognition group were required to answer yes or no to a series of questions relating to specific features of a N.Z. 50 cent coin they were also asked to rate how confident they were that their answers were correct. The recall group were asked to draw the features of both sides of the coin. The hypotheses that the recognition group would score higher than the recall group was supported as was the theory that the heads side of the coin would prove easier for both groups to remember than the tails side.It was concluded that deep processed memories, as in the way that certain distinguishing features of a coin or other everyday familiar objects are easier to retrieve than detai ls of the same object that do not hold as much relevance and thus shallowly processed within the memory.English: Hermann EbbinghausMost of us can recognise everyday objects, people we have met or other everyday aspects involving memory with little or no though at all. However when required to remember specific details of an item that most would be extremely familiar with it becomes apparent that memory is not as simple as one may think. A series of studies conducted by Nickerson and Adams (1979) asked how detailed and accurate is ones memory for a common object. Using the visual details of the US penny, their experiment showed that among their participants, those in the group assigned to memory recognition were superiour to those assigned to memory recall.

Wednesday, March 4, 2020

High Temperature Thermoplastics

High Temperature Thermoplastics When we talk about polymers, the most common distinctions we come across are Thermosets and Thermoplastics. Thermosets have the property of being able to be shaped only once while thermoplastics can be reheated and remolded to several attempts. Thermoplastics further can be divided into commodity thermoplastics, engineering thermoplastics (ETP) and high-performance thermoplastics (HPTP). High-performance thermoplastics, also known as high-temperature thermoplastics, have melting points between 6500 and 7250 F which is up to 100% more than standard engineering thermoplastics. High-temperature thermoplastics are known to retain their physical properties at higher temperatures and exhibit thermal stability even in the longer run. These thermoplastics, therefore, have higher heat deflection temperatures, glass transition temperatures, and continuous use temperature. Because of its extraordinary properties, high-temperature thermoplastics can be used for a diverse set of industries such as electrical, medical devices, automotive, aerospace, telecommunications, environmental monitoring, and many other specialized applications. Advantages of High-Temperature Thermoplastics Enhanced Mechanical PropertiesHigh-temperature thermoplastics show a high level of toughness, strength, stiffness, resistance to fatigue and ductility. Resistance to DamagesHT thermoplastics show increased resistance to chemicals, solvents, radiation and heat, and do not disintegrate or lose its form upon exposure. RecyclableSince high-temperature thermoplastics have the ability to be remolded several times, they can be easily recycled and still display the same dimensional integrity and strength as before. Types of High-Performance Thermoplastics Polyamideimides (PAIs)High-performance polyamides (HPPAs)Polyimides (PIs)PolyketonesPolysulfone derivatives-aPolycyclohexane dimethyl-terephthalates (PCTs)FluoropolymersPolyetherimides (PEIs)Polybenzimidazoles (PBIs)Polybutylene terephthalates (PBTs)Polyphenylene sulfidesSyndiotactic polystyrene Noteworthy High-Temperature Thermoplastics Polyetheretherketone (PEEK)PEEK is a crystalline polymer that has good thermal stability because of its high melting point (300 C). It is inert to common organic and inorganic liquids and thus has high chemical resistance. In order to enhance mechanical and thermal properties, PEEK is created with fiberglass or carbon reinforcements. It has high strength and good fiber adhesion, so does not wear and tear easily. PEEK also enjoys the advantage of being non-flammable, good dielectric properties, and exceptionally resistant to gamma radiation but at a higher cost. Polyphenylene Sulfide (PPS)PPS is a crystalline material that is known for its striking physical properties. Apart from being highly temperature resistant, PPS is resistant to chemicals such as organic solvents and inorganic salts and can be used as a corrosion resistant coating. The brittleness of PPS can be overcome by adding fillers and reinforcements which also have a positive impact on PPS’s strength, dimensional stability, and electrical properties. Polyether Imide (PEI)PEI is an amorphous polymer that exhibits high-temperature resistance, creep resistance, impacts strength and rigidity. PEI is extensively used in the medical and electrical industries because of its nonflammability, radiation resistance, hydrolytic stability and ease of processing. Polyetherimide (PEI) is an ideal material for a variety of medical and food contact applications and is even approved by the FDA for food contact. KaptonKapton is a polyimide polymer that is able to withstand a wide range of temperatures. It is known for its exceptional electrical, thermal, chemical and mechanical properties, making it applicable for use in a variety of industries such as automotive, consumer electronics, solar photovoltaic, wind energy and aerospace. Because of its high durability, it can withstand demanding environments. Future of High Temp Thermoplastics There have been advancements with regards to high-performance polymers previously and it would continue to be so because of the range of applications that can be carried out. Since these thermoplastics have high glass transition temperatures, good adhesion, oxidative and thermal stability along with toughness, their use is expected to increase by many industries. Additionally, as these high-performance thermoplastics are more commonly manufactured with continuous fiber reinforcement, their use and  acceptance  will continue.