Visual Light Microscopy ( Sem ) Essay

Visual Light Microscopy ( Sem ) Essay

Length: 949 words (2.7 double-spaced pages)

Rating: Better Essays

Open Document

Essay Preview

Visual light microscopy provides a relatively inexpensive and quick way for someone to observe features in a sample such as layer shift in composites, porosity in ceramics, or cross sectional views for welding. In fact, VLM is often a go to means for engineers and scientists to examine the microstructure of materials. Unlike other processes such as scanning electron microscopy (SEM) there is no requirement for sample preparation beyond using slides or hot/cold mounting procedures along with relatively simple grinding and polishing procedures. Visual light microscopy utilizes a microscope which passes visible light through or reflected from a sample through multiple lenses to generate a magnified version which is detected by one’s retina directly or imaged onto a photographic plate so that it may be captured digitally.
There are several optical principles including image formation, magnification, resolution, brightness/contrast, and depth of field. Image formation deals with how light is reflected off of a sample through a array of lenses to produce an image that can be recognized by the human eye or transferred to a digital format. Magnification is the process of making a image larger by a certain scalar quantity, total magnification depends of the focal length and image distance. Resolution is the ability to differentiate between closely spaced features and is controlled by diffraction effects. Resolution can be improved by decreasing the wavelength of light (use blue light), increasing the refractive index of the medium or the aperture semi-angle (using oil-immersion lenses). Brightness is the intensity of the light that lights up the sample while contrast is the change in intensity of the image. Depth of field is the range of ...

... middle of paper ...

...liquid is comprised of dendrites and the partially melted zone under the weld material exhibits columnar dendrites which are to be expected as the temperature gradient drives theses dendrites to grow in an orthogonal direction from the partially melted zone to the center of the weld bead. Also, the grain size in these areas are relatively small making for a fine grain structure which is likely due to the fast cooling rate since these are the uppermost regions of the weld. The heat affected zone exhibited grain grown which is due to the amount of heat added by both the TIG and CMT processes and since this region is under the rest of the weld it takes longer to cool which allows the grains to grow. Overall, VLM allowed many characteristics of this welding technique to be observed rather easily which is why it can be a very useful materials characterization technique.

Need Writing Help?

Get feedback on grammar, clarity, concision and logic instantly.

Check your paper »

The Evolution of the Light and Electron Microscope Essay

- Birth of the Light Microscope In Circa 1000AD the first vision aid was invented (the inventor is unknown) it was called a reading stone. It was described as a glass sphere that magnified reading material when placed on top of an object. Someone picked up a piece of transparent crystal thick in the middle than at the edges, they looked through it, and realized it made objects look bigger. “Magnifying glasses” are mentioned during the first century A.D by Roman philosophers Seneca and Pliny the Elder, but never used much until the invention of spectacles, at the end of the 13th century....   [tags: evolution, eletron, light]

Better Essays
1863 words (5.3 pages)

Essay on Comparing the Light and Electron Microscope

- Comparing the Light and Electron Microscope In this essay I am going to be comparing the light and electron microscope, I will look at the advantages and disadvantages of each microscope and then analyse my findings to see if one is better than the other. The light, or optical microscope as it is also known was invented in the 17th century, it has been refined in many ways over the years but it is essentially still the same. The light microscope works by; light rays from a light source beneath the stage are through to glass lenses in series....   [tags: Papers]

Better Essays
846 words (2.4 pages)

Visual Impairment And Physical Impairment Essay

- Sensory impairment is defined as a reference “to people with either visual or hearing impairments or both – the extent of those impairments will vary from person to person” (Bathnes). Visual impairment is defined as the loss of vision that cannot be repaired or corrected by any kind of treatment. Visual impairments break off into three categories, sight impaired, severely sight impaired, and Age-related macular degeneration (AMD). Sight impaired according to Bathnes is defined as “the term to identify someone who as been assessed by an ophthalmologist as being substantially and permanently handicapped by defective vision caused by congenital (present at birth) defect, illness or injury.” Sev...   [tags: Ophthalmology, Blindness, Visual impairment]

Better Essays
2266 words (6.5 pages)

The Transformation And Development Of The Compound Light Microscope Essay

- Up until the 20th century living organism were classified as either plants or animals. By the 1970s, however the five kingdoms system (Plants, Animals, Fungi, Bacteria and Protista) was accepted as they realised that not all organisms can be classified as just plants or animals. In the late 1970s researchers from the University of Illinois made an astonishing discovery that changed the field of biology for years to come (University of ILLinois, n.d.). They discovered bacteria that survived at extreme temperatures and produced methane....   [tags: Bacteria, Archaea, DNA, Organism]

Better Essays
1675 words (4.8 pages)

Essay on History of the Microscope

- "Of all the inventions none there is Surpasses the noble Florentine’s Dioptrick Glasses For what a better, fitter guift Could bee in this World’s Aged Luciosity. To help our Blindnesses so as to devize a paire of new &Artificial eyes By whose augmenting power wee now see more than all world Has ever doun Before.” Henry Powers, 1664 The Beginnings Of the five senses, the most important is sight.It aids in the process of gathering information about the environment that we are part of.However, this visual gathering is adequate only to a certain point....   [tags: Microscope Science biology History Essays]

Better Essays
2872 words (8.2 pages)

The Light in the Forest by Conrad Richter Essay

- The Light in the Forest Conrad Richter presents a historic fictional work describing the colonial frontier in The Light in the Forest.  True Son, born as John Butler, was captured by the Lenni Lenape Indians at the age of four.  He was adopted by them and raised as the son of their chief, Cuyloga.  He became a part of the Indian culture.  Later the Indians made a treaty with the whites and all white captives were to be returned to their people, including 15-year-old True Son.  However, True Son had learned to hate the white men and their ways....   [tags: The Light in the Forest]

Free Essays
770 words (2.2 pages)

Electron Microscopy and the Study of the Cell Essays

- Electron Microscopy and the Study of the Cell Electron Microscopes have revolutionised today’s understanding of the cell. In 1838 Scheleiden, a botanist theorised that the basic unit of a plant was a cell, the following year the scientist Schwann came up with a similar hypothesis this time related to animal cells, their combined ideas gave us the cell theory, the idea that all living things were made from similar building blocks, cells. It took 100 years before this idea was confirmed with the invention of the electron microscope....   [tags: Papers]

Free Essays
719 words (2.1 pages)

Microscopy Essay

- Microscopy Summary The entire exercise was all about caring for and using the microscope. We performed various activities that enabled us to familiarize ourselves with the parts and uses of the microscope. Using the microscope, we observed different objects such as cotton, silk, hair, and even a letter "e." We viewed it using both the low power objective and the high power objective. We did these activities in order to better understand how the compound light microscope works and also to learn about the different procedures in setting up a slide....   [tags: Biology]

Better Essays
867 words (2.5 pages)

Essay on Electron Microscopy Investigation

- Electron Microscopy Investigation The electron microscope was first made when biologists found a problem with the resolution of a light microscope. Resolution means “the ability to distinguish between two points”; the problem is that the maximum resolution of a light microscope is 200nm. So if two points are closer together than 200nm they are seen as one. One example of this problem is that under a light microscope the centrioles in an animal cell appear as one, however when viewed under an electron microscope we can see that there are two centrioles at right angles to each other....   [tags: Papers]

Free Essays
694 words (2 pages)

Confocal Microscopy Lab Essay

- Confocal Microscopy Lab Confocal microscopy uses a laser that produces excitation light. This laser light reflects off of a dichroic mirror and then the laser light hits two mirrors that are mounted on motors. The mirrors then scan the laser light across the sample. Dye that is found in the sample then fluoresces (Weeks, 2003). Filamin was labeled with a red fluorescent label rhodamine (TRITC) and actin was labeled with the green fluorescent label fluoroscein (FITC) which was conjugated to the actin-binding fungal toxin phalloidin....   [tags: Ovarian Ring Canal Medical Technology Essays]

Better Essays
861 words (2.5 pages)