Radiation ultimately interacts with atoms, DNA or other cellular components, still, radio sensitivity and specificity is species correlated phenomenon.

Explain this statement   

How the Fixer convert undeveloped Silver bromide crystals left on the film into a soluble compound and dissolve them away?                                                                      

What is the advantage of Molybdenum used as target material in X-ray Tube?

Define reticulation and what is the role of Time and Temperature in the process of film developing?"

Radiation and Radio Sensitivity

 Statement Explanation:

 This process concerns the atom, DNA or any other structures existing in biological systems and radiation affecting them. The consequences of this interaction—damage or mutation—depend on the organism’s reaction to radiation, its sensitivity and specificity. This is species dependent: power of species differs depending on the cellular and molecular radiation sensitivity. For instance the effects of radiation on the human cells may be completely different from those observed in bacterial cells or plant cells. Some of the parameters that affect end-point values include differences in DNA repair ability of cells, cell-division cycle and the existence of special protective structures in certain cells.

 Fixer in Film Development

 Fixer Process:

 The fixer is a chemical compound that in the process of development of motion picture films, it is used to remove the unexposed and the undeveloped silver bromide crystals from the film strip. The process involves:

 Conversion to Soluble Compound: It has chemicals such as hypo or sodium thiosulfate which react with the unexposed silver bromide crystals on the film or photograph. Some of the products formed include soluble silver thiosulfate complex and some other byproducts of silver bromide.

 Dissolving Away: These soluble compounds can then be washed away during the fixing process, this leaving behind only the developed ‘silver metal’ which is visible and constitutes the image on the film.

 The use and benefits of Molybdenum in X-Ray Tubes

 Molybdenum Target Material:

 Molybdenum (Mo) is used as a target material in X-ray tubes, particularly in mammography, due to several advantages:Molybdenum (Mo) is used as a target material in X-ray tubes, particularly in mammography, due to several advantages:

 Characteristic X-ray Spectrum: Molybdenum targets emit X-rays with the energy content that is very suitable for imaging of soft tissues including the breast tissues. The energies that are produced by molydenum is specific for X-ray which is suitable for visualizing the delicate structures of the breast tissues.

 Controlled Radiation Dose: Molybdenum assist in achieving a controlled and a lower dose of radiation when compared to a traditional SPECT and still produces images of high quality.

 Image Contrast: Molybdenum assists in improving contrast in areas of soft tissue, which is necessary in breast tissue to be able to identify an abnormality.

 Reticulation in Film Developing

 Reticulation Definition:

 In the process of development of the photograph, a particular condition, known as reticulation, develops in which a crack pattern or a ‘‘reticulation pattern’’ of the surface of the film or the print is formed. This phenomenon is typically undesirable and results from:This phenomenon is typically undesirable and results from:

 Temperature Shock: Fluctuation in temperatures between the solutions for instance developer, stop bath and fixer also contributes to reticulation because it makes the layer of the emulsion to shrink or expand in some areas.

 Role of Time and Temperature:Role of Time and Temperature:

 Time: Any of the developing chemicals or long development times are likely to worsen reticulation if one gets overwhelmed by them.

 Temperature: That is why, normal and suitable temperature has to be kept throughout all the stages of developing process in order not to cause reticulation. Any variation with the recommended temperatures results to physical changes of the emulsion and pattern as well as cracks.

 In conclusion, it is very important that time and temperature in the film processing have to be controlled so as not to facilitate the formation of reticular patterns and so as to achieve a better photograph quality.