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The contact lens separates the tear film into two

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the contact lens separates the tear film into two layers. [2] This procedure is inefficient because the separation of the tearfilm causes an increase in friction which leads to a greater rate of deformation of the oculus’ surface. There are those whowish to improve the old, and there are those who wish to experiment and create other options. A study done at theNational Taiwan University of Science showcases that’ by adding silica soil the Dk values as well as Young’s modulusincrease, however, the visual clarity decreases. [3, Fig 1] A new proposition, the addition of a mucin macromolecular coatallows for a wider range of materials for use by creating a hydrophilic surface which protects the surface of the eye fromotherwise damaging materials. [2] Another issue that contact lenses could resolve is colour vision deficiency. The additionof noble nanoparticles allows for the alteration of the optical properties of the silicone hydroxyl lenses which polarizecertain colour filters depending on the concentration of each nanocomposite. [4]Figure 13.Effect of silica soil nanoparticles content on oxygen permeability (Dk) and Young’ modulus
Anthony PozharskiyMaterial Selection for Hip ImplantsTo simulate a human joint, the most effective method is the use of endo-prosthetics with approximatelyone million procedures done every year [1].In terms of endo-prosthetics, there are many considerations to bemade for its material, especially with hip joint replacements. Hip implants are created by inserting a ball andsocket into the femur to simulate a hip joint [1]. The main functions of a successful hip joint replacement shouldbe that it could withstand loads experienced by the body, resist corrosion and fatigue, have low friction, andhave debris that is well tolerated by the body [2]. With many patients receiving these implants at a young age,the material must be durable enough to last a lifetime to avoid complications of repeating procedures [1]. Thenumber of materials that satisfy the requirements to create an effective hip implant is very limited, most ofwhich are ceramics or metals due to their strength and mechanical properties [1]. The most popular materialused for hip implants is titanium, due to its excellent biocompatibility and corrosion resistance [3]. Othermaterials such as cobalt-chromium alloys, alumina, and stainless steel are also common materials used for hipimplants [2]. These materials are good candidates for a hip implant due to their mechanical properties such asthe high Young modulus and hardness of the material [4]. These properties allow the implant to support loadson the body as well as be more fatigue resistant, allowing for a prolonged lifespan of the implant [4].Biocompatibility is another major factor in the material selection, as they should be biologically inert to avoidinternal problems caused by the implant [1]. Low friction is also necessary to avoid the creation of debris andallow for smooth movement of the joint within a patient [2].

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