Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
Transmission electron microscopy:
Around 1931-32 two German scientists. Knoll and Ruska. Invented transmission electron microscopy, and built the first transmission electron microscope (TEM) in 1938 .Hillier 1940 built a high resolution TEM. A strong beam of electrons, issued from tungsten filaments, passed through vacuum and focussed by electromagnets, producing a radiation wavelength of about 0.0005nm is used to illuminate objects in this electrons strike against a fluorescent screen, or directly fall onto a photographic film, producing an electron micrograph. A practical resolution of about 5 a and magnification of one to several hundred thousand have been achieved by this microscopy, combined with modern cytological techniques, this microscopy has enabled scientists to know of many finer details of cell structure down to the macromolecular level. This knowledge of ultra structure or sub microscopic structure of the cell has resulted into the establishment of Molexular Biology.
Knoll (1935) demonstrated the feasibility of scanning electron microscopy achieving a resolution of about 30 a for three dimensional study of surface topography of objects in considerable details. Von Adrienne (1938) built first scanning electron microscope (SEM) .It is smaller and simpler than TEM. Electrons used SEM does not pass through the object, but are simply scattered from the surface of the object.
Portal Hypertension: If you review the portal circulation you may recall that normal blood flow to and from the liver depends on proper functioning of the portal vein, the he
Explain about the Food Science and Technology? Food Science and Technology are so inextricably linked that usually these are treated as one field of study. While Food Science d
Convert 3.5°F to Celsius Four hundred pounds is how many kilograms?
What is an example of animal coming from the phylum arthropoda?
Explain Energy demand for Sedentary or Light Activity Lifestyles? These people have occupations that do not demand much physical effort, are not required to walk long distances
Explain diet from Lifestyle Risk Factors ? The lifestyle factors are the way of living of an individual and comprise of the diet, smoking, alcohol, physical activity and stress
a) Explain what is meant by ovulation. b) How often does it happen in humans? (a) Ovulation is the release of an ovum from a mature follicle in the ovary.
Multicausal Nature of Cancer With several dividing cells in the organism and the various proto-oncogenes and tumor suppressor genes that can be changed to cause cancer. one m
Physiognomy and Pattern Physiognomy is the general appearance of vegetation as determined by the growth, form of dominant species. It may be considered a synthetic character
Which one of the following statements about human sperm is correct? 1. Acrosome has a conical pointed structure used for piercing and penetrating the egg, resulting in fertilis
Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd