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.
Define the Causes of Failures of Root Canal Treatment 1. Errors in diagnosis and treatment planning 2. Coronal leakage ( inadequate restorative protection) 3. Lack of kno
where we find annelid
Sinus Perforations The maxillary antrum can sometimes be inadvertently penetrated. Through careful pre-operative planning using radiographs, including axial scans, this compli
#question about fish
Excretion in Non-Chordates Excretion as described under Introduction of this unit refers to removal of the waste products of metabolism - carbon dioxide (CO 2 ) and water rele
Determination of vitamin B 12 Spectrophotometric determination of the characteristic ultraviolet absorption is suitable for the determination of pure vitamin B 12 or of pure
Question Write a short note on the following: 1 Dihybrid cross 2 Supplementary interaction 3 Maternal effect 4 Hardy Weinberg Equilibrium 5 What is Linkage? Ex
Q. Issues to be discussed while counselling a diabetic patient ? Issues to be discussed · Counselling at Diagnosis · Diabetes is Controllable · Counselling for Day
Where do the light reactions occur in prokaryotic and eukaryotic cells?
Determine the intracellular concentration of TRVA Consider Neuron B in the frog central nervous system whose plasma membrane has a previously unknown channel that is selectly c
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