ELECTROCARIAN

Martin Jones, 42 years old builder by profession  had been blind for 12 years after a tub of white hot aluminium exploded in his face as he worked at a scrapyard. And now he can see through his tooth shocked.... that  what I was  when I first heard. The real hero behind the scene is   Mr Liu. He is a corneal specialist and Consultant Ophthalmic Surgeon based at Sussex Eye Hospital, Brighton. What Liu Did?? One of Mr. Martin's teeth was extracted and a small hole was drilled into it to accommodate a special optical lens. The tooth was then inplanted into Martin's cheek for three months whereby new tissue and blood vessels grew. The lens was then fitted into the hole and the tooth was inserted into his eyeball. Within a few weeks Martin could see for the first time in 12 years. The implant works via the lens allowing light into his eye which restores the vision.

  Results obtained from X-ray diffraction powder patterns of barium praseodymium titanate confirms the formation of tungsten bronze type crystal structure with orthorhombic symmetry. Dielectric constant (ε') as a function of frequency at room temperature decreases for increasing Pr contents for sample 1 and 2. Loss tangent decreases with increasing Pr content linearly as a function of frequency from 100 Hz to 1 MHz. Very low AC conductivity has been observed for the prepared samples.  It basically decreased with composition, but increased linearly with frequency. Variations of dielectric constant as a function of temperature at different frequencies, 100 Hz, 1 KHz, 10 KHz, 100 KHz and 1MHz, are investigated and it is found that variation in dielectric constant as a function of temperature decreases with increase in Pr contents. It can be easily concluded that reasonably good dielectric properties have been obtained for the two synthesized sa

This chapter deals with the results obtained from experimental procedures for dielectric behaviour of Barium praseodymium titanate ceramic materials.  4.1 X-Ray diffraction  The X-ray diffraction patterns of synthesized samples BaPr1.33Ti3O9 and BaPr2Ti4O12 (namely, sample 1 and sample 2 respectively) are shown below: Figure 4.1: XRD patterns of synthesized samples BaPr1.33Ti3O9 & BaPr2Ti4O12 It shows that tungsten bronze type structure is formed with an orthorhombic symmetry. The variation in relative intensities of peaks may be related to the occupation of lattice sites by the substituted ions.  4.2 DENSITY MEASUREMENT  The density of the synthesized samples has been measured by archimedies method at 30˚C using distilled water as displacement fluid. The equation used to calculate density is as under.   Density of sample = mass in air * density of distilled water                                mass of sample and wire -+ mass of wire For sample 1 ( BaPr 1.33

3.1 WEIGHING 3.1.1 Definition A weighing scale  is a measuring instrument for measuring the weight or mass of an object. There are two techniques used for measurements: ·          Spring scale Measurement ·          Analytical Measurement 3.1.2 Techniques of weighing 3.1.2.1 Spring scale A spring scale measures weight by the distance a spring deflects under its load. A balance compares the unknown weight to a standard weight using a horizontal lever. This process uses a spring with a known spring constant (see Hooke's law) and measure the displacement of the spring by any variety of mechanisms to produce an estimate of the gravitational force applied by the object. Weighing scales are used in many industrial and commercial applications, and products from feathers to loaded tractor-trailers are sold by weight. Specialized medical scales and bathroom scales are used to measure the body weight of human beings. Spring scales measure weight, the local force of gravity on an ob