Essays on Electron Microscope

Raman spectroscopy is dependent on scattering of light. When light interacts with matter, energy exchange can take place through absorption, simulated emission, Raman scattering or spontaneous emission. In Raman scattering, the emitted photons have less energy and lower frequency in comparison with the absorbed photons. Some energy of the emitted photons is transferred to the molecules. Raman spectroscopy is a method which collects the chemical fingerprints associated with molecules. Every molecule has different levels of vibrational energy and the emitted photons experience shift in their wavelengths. The wavelength shifts are collected,examined and analyzed for sample identification. Raman spectroscopy ...

Introduction

There are different perspectives that are being peddled concerning fracture processes, this has led to confusion on what actually this term means. In this review, a deeper understanding is sort by analyzing different aspects of the nomenclature of the fracture process. In order to gain a deeper understanding of the failure processes several aspects are put in consideration key among them will be discussed below and include; the energy of fracture, macroscopic structure path and microscopic fracture mechanisms.

Energy to Break

The toughness of a material is the measure of the absorbed energy during and before fracture. The toughness of the material ...

Scanning electron microscope uses a beam of electrons to form images that reveal the topography and composition of a body. Before being focused on the object, incident electrons have high amounts of kinetic energy. Incident electrons interact with the surface of the specimen, and this interaction is determined by the rate of the acceleration of the incident electrons. Energetic electrons are usually released from the surface of the sample when the incident electrons come into contact with it. The interaction results in the formation of scatter patterns that interpret into the shape, composition, size, and texture of the specimen. ...

Introduction:

Transmission electron microscope (TEM) is the type of a microscope that uses a beam of electron rather than visible light to illuminate the specimen. Besides, while light microscope uses glass lens to focus light to the specimen, TEM uses electromagnetic lenses for focusing of the electron beam. TEM has a higher resolving power than the light microscope because the electron beam it uses for illumination has a much lower wavelength than visible light. During the operation of TEM, some electrons passing through the specimen get scattered and disappear from the beam. However, the unscattered electrons reach a fluorescence screen ...

- Introduction A compound light microscope represents two or more lens. The term compound refers to multiple or mixture. In compound light microscope built with binocular lens and objective lens. The binocular lens present near the eyepiece and objective leans near to nosepiece. The objective lens helps in enlargement of images and also to collect the light source. According to the requirement the objective lens also changes. In advanced compound light microscope the phase contrasts also possible. In earlier 1595 Zacharias Janssen invented the first light microscope using collapsing tubes. It produced a magnification of 9x. Now the magnification ...

1. Introduction to the Technique Magnification and high resolution imaging are very important in materials science, especially at present when nanotechnology materials are being created. Magnification and high resolution imaging can help in the characterization, identification, and confirmation of the existence of the desired material. Magnification and high resolution imaging become problems when the size of the assessed material becomes too small; such as, they are beyond the micrometer scale. Ordinary techniques in microscopy such as light microscopy where in a traditional light microscope is used could not suffice. Fortunately, in 1931, two scientists named Ernst Ruska and Mx ...

Introduction

The microscope is derived from two Greek words, mikros and skopeo. Mikros means small while skopeo means “look at.” Thus, the two words form the word mikroskopeo that refers to looking or observing small objects. Since the beginning of scientific developments, there has been an interest to look at the smaller details of the world around us. Biologists have taken the lead in the quest to uncover such small details through their desire to examine cells, viruses, bacteria, and colloidal particles. Material scientists have wanted to observe the limitations and inhomogeneities in metals, ceramics, and crystals. Geologists have also ...

Book Review of

“The Hot Zone” written by Richard Preston is a non-fiction English book published by Anchor in 1995. It contains 420 pages and based on Richard Preston article “Crisis in the Hot Zone.” It is a thriller that deals with the source and occurrences relating to viral hemorrhagic fever especially Ebola viruses and Marburg viruses. The filo viruses, Ebola Virus called EBOV, Sudan Virus called SUDV, Marburg Virus called MARV and Ravn Virus called RAVV are the agents of level four of Biosafety. They are enormously hazardous to humans due to being very contagious and with an extraordinary casualty rate. There is ...

Electron microscopes refer to those microscopes that make use of an electron beam to light a specimen producing a magnified image. These microscopes are used to study structures that are either invisible through naked eyes or those that are too small to be clearly seen using a light microscope. The two major types of electron microscope are Transmission Electron Microscopy or TEM and Scanning Electron Microscopy or SEM (Mooney, 1996). Transmission Electron Microscopy employs a high voltage electron beam in order to create an image (NE, 2013). The TEM is made up of various components including electromagnetic lens system, electron source, sample ...

Definition

Magnification refers to the process of making an object larger or smaller in size. It can be said basically to be the altering of the size the object. The magnified object is referred to as an image. Therefore the magnified object is shall only appear larger or smaller in size with the physical size maintained. This change is calculated and given in a numerical number referred to as the magnification.

Areas where magnification is used

Magnification is used in many fields of study and real life situations. In biology, small objects are magnified so as to be viewed properly. This involves the use of microscopes. ...

Biology

The electron microscope has proven to be invaluable in the study of proteins and has enhanced our understanding of cellular biology. The importance to understanding disease and trauma to the body as well as treatments cannot be overstated. Genetic research such as studies of the mechanisms of protein folding is better understood due to electron microscopy. The image of a sample such as a slice of a fibril or a “newly synthesized chain of amino acids” (Dobson, 2003, p. 884) created by an electronic beam. The Transmitting Electron Microscope (TEM) transmits the electron beam through a sample whereas the SEM scans the surface ...

- Toxicology With the help of an electron microscope, it becomes possible to carry out a detailed study of the toxic lesions in order to understand the toxicological events. - Electron Tomography and Sub-cellular Structure Electron tomography is a technique which is used to visualize and investigate the three-dimensional structural information about the sub-cellular macromolecular specimens. It is a three-dimensional electron microscopy technique used for sub-cellular imaging.

Principles of Function

- Electrostatic Interactions In an electron microscope, electrostatic and electromagnetic lenses are used to selectively control and focus the electron beam to generate images. In atoms, with the increase in atomic ...

Abstract

Microscopy is the science of viewing objects that are very minute and can only be viewed by an instrument called a microscope. The science began in the 16th century and has been progressing into viewing specimens at higher resolutions, greater magnifications, and in 3-D. These advancements are in the three sub-branches of microscopy which are scanning-probe, optical, and electron microscopy. The paper analyses the latest advancements in the three fields indicating what the invented microscopes can be used in science.

Introduction

In Biology, Microscopy is the technique of using microscopes to view objects that are very minute and can only be ...