Melamine Polyimide Composite Fire Resistant Intumescent Coatings

Components of intumescent coatings acid source, carbon source and blowing agent like melamine linked together by a binder provide cumulative fire retardant properties. When temperature of the coating surface reaches a critical temperature under the heat of flame, the surface begins to melt and is converted into highly viscous liquid. Simultaneously, reactions are initiated that result in the release of inert gases with low thermal conductivity. These gases are trapped inside the viscous fluid forming insulating char. The special composite of melamine polyimide, a C source and melamine a blowing agent showed high performance heat resistance in the present study. Polyimides have excellent heat and chemical resistance, excellent adhesion to a number of substrates and superior mechanical properties, such as high flexural modulus and compressive strength. Polyimides are also known to possess outstanding dimensional stability under loads, which allows their use in high temperature environments. Effect of the monomer on chemical reactivity between the binder and the intumescent additives has been studied by thermo-gravimetric analysis, differential scanning calorimeter and FTIR analysis. Thermal insulation studies by various intumescent composite coatings, applied on aluminium plates provided useful time temperature profiles.Defence Science Journal, 2013, 63(4), pp.442-446, DOI:http://dx.doi.org/10.14429/dsj.63.487

Contactlesss Eddy Current Braking System in Automobiles

In mechanical type braking system which are being used now days to stop or retard the automobile by means of artificial frictional resistance. This causes skidding and wear & tear of the vehicle which may cause serious problems. If the speed of the vehicle is very high, then it will not provide high braking torque, which may cause less frictional resistance during braking action and it will cause problems like accidents. These drawbacks of mechanical type brakes can be overcome by a simple, effective and efficient mechanism of braking system which is called as �The Non contactless braking system or Eddy current braking System�. It is a non contact type braking system then it is an abrasion-free method for braking in automobiles. It makes use of the opposing tendency of Eddy current. Eddy current are the loops of or swirling electric current produced in a conductor,by changing the magnetic field .The change of magnetic field is required for generating flux by the principle of faraday law. In eddy currents braking energy such as kinetic energy transform into heat, which is an unused energy. In some applications, the useful energy is lost i.e not particularly desirable. But there are some practical applications such an application is the eddy current brake.[1]This paper report explores the working principle of eddy current brake mechanism. In eddy current braking, like a conventional friction brake, which is responsible for slowing an object, such as a train or a roller coaster etc. In the friction braking, the pressure is applied on two separate objects, but in eddy current braking an object is stopped by creating eddy currents through electromagnetic induction which creates resistance, and in turn either heat or electricity. For such a breaker, we give analytical formulas considering end effects for its magnetic field, eddy current distribution, forces according to the secondary relative permeability, and conductivity. The results given here are purely analytic.[2]The principle of braking in road vehicles involved the conversion of kinetic energy into heat. This heat energy conversion therefore demands and appropriate rate of heat dissipation if a reasonable temperature and performance stability are to be maintained. The electromagnetic brakes works in relatively cool condition thus it avoid problem that friction brake face by using a totally different working principle and installation location. By using electromagnetic braking as substitute retardation equipment, the friction braking may be used less as compared and therefore practically never reach high temperature. Thus by eddy current braking brakes have a longer life , and potential �brake fade� problem can be avoided, it is apparent that the electromagnetic brake is an essential compliment to the safe breaking of vehicles.[3

Drug-Induced Erythema Multiforme

Erythema multiforme (EM) is an acute inflammatory, mucocutaneous, psychosomatic, and vesiculobullous condition that varies from minor to major forms. The acral distribution of target lesions is a characteristic of this condition. The aetiology of erythema multiforme is multifactorial. 90% of the cases are triggered by a herpes infection, whereas 10% occur secondary to drug intake. The offending drugs include nonsteroidal anti-inflammatory drugs, antibiotics, and anticonvulsants. The present case series discusses four cases of drug-induced erythema multiforme and their management