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Showing posts from April, 2015

Smart concrete using nano particles

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Nano concrete
Addition of nano particles gives significant improvement to concrete than conventional concrete. Addition of nano particles improves the bulk properties of materials by controlling or manipulating at the atomic scale due to nanoscale attack by alkali silicate reaction. It is possible to obtain thinner final products and faster setting time besides lower levels of environmental contamination.
Nano concrete is a concrete made with Portland cement particles that are less than 500nm as a cementing agent as against normally used cement particle which range in size from a few nano-meters to a maximum of about100 micro meters. The benefits are cessation of contamination caused by micro silica solid particles, lower cost per building site, high initial and final compressive and tensile strengths, good workability, cessation of super plasticizing utilization and cessation of silicosis risk of concrete.
Nanomaterials used are nano-silica (nano-SiO2), nano-titanium oxide (nano-TiO2),…

Nanotechnology against dengue

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Dengue Fever
Dengue infection is usually associated with tropical countries and causes high fever, headache, rash, severe joint and muscle pain, haemorrhage, and death. Dengue infection is caused by any one of four related viruses that are transmitted to humans by the mosquitoes.
There is no vaccine against dengue; nor have any specific antiviral medications shown to be effective to treat it. An effective vaccine would need to induce the immune system to produce antibodies against all four dengue virus serotypes, a task that so far has proven too difficult to accomplish and development and testing of antiviral medications is complicated and expensive. For dengue prevention and treatment the only existing ways are to control the mosquito populations responsible for transmitting the disease and to avoid being bitten by infected mosquitoes.
Researchers of James Cook University use nanotechnology to monitor a small protein that binds to antibodies, enabling it to be used to identify the pot…

Nanotechnology in diabetes treatment

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Diabetes is a chronic disease that affects global population. Diabetes mellitus is a commonly seen chronic disease, which seriously threatens the health of human beings. Diabetic patients control their blood-sugar levels via insulin introduced directly into the bloodstream using injections. However effective monitoring and treatment options are important.
Nanotechnology offers some new solutions in treating diabetes mellitus. Nanotechnology, particularly nanoparticles show great promise in improving the treatment and management of diabetes.
Insulin and blood sugar
A new method uses nanotechnology to rapidly measure minute amounts of insulin and blood sugar level to assess the health of the body’s insulin-producing cells. As oral insulin consumption is useless a new system has been developed based on inhaling the insulin (instead of injecting it) and on a controlled release of insulin into the bloodstream (instead of manually controlling the amount of insulin injected). Further nanopart…

Semiconductor nanoparticles

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A nanoparticle (or nanopowder or nanocluster or nanocrystal) is a microscopic particle with at least one dimension less than 100 nm. Nanoparticles are of great scientific interest as they are effectively a bridge between bulk materials and atomic or molecular structures. Nanoparticles exhibit a number of special properties relative to bulk material.Nanoparticles of many other materials, including metals, metal oxides; carbides, borides, nitrides, silicon, and other elemental semiconductors are available.
Mechanism
Their unique physical properties are due to atoms residing on the surface. The excitation of an electron from the valance band to the conduction band creates an electron hole pair. Recombination can happen two ways as radiative and non-radiative leading to radiative recombination to photon and non-radiative recombination to phonon (lattice vibrations).
Also the band gap gradually becomes larger because of quantum confinement effects giving rise to discrete energy levels, rathe…