دانلود رایگان ترجمه مقاله استفاده از مواد افزودنی خوراک نانو در تغذیه دام – Ejmanager 2015

استفاده از افزودنی های خوراکی نانو در تغذیه دام

Use of Nano Feed Additives in Livestock Feeding 

Introduction

The word nano technology is derived from the Latin nanus, meaning dwarf). Nanoparticles are of different types based on their ability to carry different ingredients and react to different environmental conditions. Nanotechnology is defined as the understanding and control of matter at the nanoscale, at dimensions between approximately 1 and 100 nanometers, where unique phenomena enable novel applications” according to National Nanotechnology Initiative (2013), USA. A nanometer is one billionth of a meter. The typical nanotechnology utilizes structures under 100 nanometer in size, more than 1000 times narrower than the diameter of a human hair.

History of Nanotechnology

The concepts that seeded nanotechnology were first discussed in 1959 by renowned physicist Richard Feynman in his talk There’s Plenty of Room at the Bottom, in which he described the possibility of synthesis via direct manipulation of atoms (Feynman, 1959). The term “nano-technology” was first used by Norio Taniguchi in 1974, though it was not widely known. Inspired by Feynman’s concepts, K. Eric Drexler independently used the term “nanotechnology” in his book Engines of Creation: The Coming Era of Nanotechnology, which proposed the idea of a nanoscale “assembler” which would be able to build a copy of itself and of other items of arbitrary complexity with atomic control. Also in 1986, Drexler cofounded The Foresight Institute to help increase public awareness and understanding of nanotechnology concepts and implications. Thus, emergence of nanotechnology as a field in the 1980s occurred through convergence of Drexler’s theoretical and public work, which developed and popularized a conceptual framework for nanotechnology, and high-visibility experimental advances that drew additional wide-scale attention to the prospects of atomic control of matter.

Differences between nanomaterials and larger materials

The physical, chemical, electrical, optical, mechanical, and magnetic properties at an atomic scale are quite different from those present at a larger scale, even when compared with those present at a scale of microns (10-6 ) (Buzea et al., 2007). Nanomaterials are different from larger ones because of two effects:

1. Surface effects The atoms of nanomaterials are less stable than those of larger structures since the energy required to join adjacent atoms is less. As a consequence of this, the fusion point of a given element changes. For example, the fusion point of a gold particle measuring 2.5 nm is about 657°C, which is much lower than 1,063°C, the normal fusion point of this metal at greater volumes. Cao (2004) mentioned that this phenomenon is characteristic in metals, inert gases, semiconductors and molecular crystals when the size of the particle is less than 100 nm.

2. Quantum effects Quantum points are a type of nanostructures, just a few nanometers in size that show a behaviour similar to a single atom. Their spatial arrangement allows them to have properties not proper to the element, such as magnetism in metals like gold or platinum when they are in the form of nanoparticles.