The effects of scattering and secondary radiation generated inside the material on dose equivalent rate where studied using Co60 and Cs137 sources of activity (199.8 , 177.6) MBq , respectively for different thicknesses of Al , Pb and Pb- glass . The results showed that the equivalent rate increases when the effect of scattering was included for Al and Pb shields with cobalt-60 source of energy 1.25 MeV ; and decreases for Pb shield with Cs-137 source of energy 0.662MeV .The results showed also that the atomic number of The material effects the dose equivalent rate . The Pb-glass shield was found to be more efficient in absorption than other shields.
Crude oil still affects many countries because it is one of the essential fuel sources. It makes life more manageable in modern communities and cannot be overstated because it is easy to use and find. However, the pollution caused by its use in industries such as mining, transportation, and the oil and gas business, especially soil pollution, cannot be ignored. Soil pollution is an issue in most communities because it influences people and ecology. Accidental infusions and spills of ore oils are prevalent occurrences leading to the entire or fractional exchange of the soil pore fluid by oil-contaminated soils that have affected the geotechnical engineering properties. The liquid limitations for polluted soil grades silty loam and sa
... Show MoreStereo lithography (SLA) three-dimensional (3D) printing process is a type of additive manufacturing techniques that uses digital models from computer-aided design to automatically produce customized 3D objects. Around 30 years, it has been widely utilized in the manufacturing, design, engineering, industrial sectors and its applications in dentistry for manufacturing prosthodontics are very important. The stereo lithography technology is highly regarded because it can produce items with excellent precision especially when selecting the best process parameters. This review article offers a useful and scientific summary of SLA three-dimensional printing technology and its brief history. The specific type of 3D printers which is SLA type b
... Show MoreDuring the 1970s, communicative view of language teaching began to be incorporated into syllabus design. The central question for the proponents of this view was: what does the learner want/need to do with the target language? This lead to the emergence of a teaching method (or approach) called communicative language teaching (CLT) during the late 1970s and early 1980s focusing on the functions that must be incorporated into a classroom. According to Brown (2001:43) CLT is a unified but broadly based, theoretically well informed set of tenets about the nature of language and of language learning and teaching. Harmer (2001:84) states that the communicative approach is the name which was given to a set of beliefs which included not only a
... Show MoreBackground: Fiber-optic endoscopy is an important
investigation of the large intestine, whether or not the
radiologist (barium enema) has discovered a lesion in
the bowel. Colonoscopy affords a unique opportunity
to direct visualization of entire colonic mucosa. At
the same time, the physician can obtain biopsy specimens, remove polyps, and decompress volvuli.
Most experienced endoscopists and well prepared
patients can reach the cecum in over 90% of patients.
If colonoscopy is properly performed, it has a low
risk of complications, such as perforation and bleeding.
Methods: A total of 70 consecutive patients admitted
to Endoscopy department at Al-Kindy Teaching hospital from September- 2008 to July-2009.
Background: Fiber-optic endoscopy is an important
investigation of the large intestine, whether or not the
radiologist (barium enema) has discovered a lesion in
the bowel. Colonoscopy affords a unique opportunity
to direct visualization of entire colonic mucosa. At
the same time, the physician can obtain biopsy specimens, remove polyps, and decompress volvuli.
Most experienced endoscopists and well prepared
patients can reach the cecum in over 90% of patients.
If colonoscopy is properly performed, it has a low
risk of complications, such as perforation and bleeding.
Methods: A total of 70 consecutive patients admitted
to Endoscopy department at Al-Kindy Teaching hospital from September- 2008 to July-2009.
The researcher studies and explains the content of some pictures that are published in al-Mada newspaper. The research is important as it deals with a topic that has a relation with visual culture and its role to transfer the press letter to the audience. The researcher finds that cartoonist exposed the security services through important people who have a major role in state policy and reveals the level of corruption and the weak treatments for this phenomenon and its reflection on the whole society and individuals. In addition to that, cartoonists try to encourage the public for going on the peaceful demonstrations since it is a good tool to make pressure on the government to punish the corrupts.
This research studies the effect of particle packing density on sintering TiO2 microstructure. Sintering experiment was conducted on compacts involving of monodisperse spherical TiO2 particles. The experimental results are modeled using L2-Regression technique in studing the effect of two theoretical values of 55% and 69% of initial packing densities. The mathematical simulation shows that the lower values of density compacts sintered fast to theoretical density and this reflects that particle packing density improved densification rate because of the competing influence of grain growth at higher values of densities.
CdS and CdTe thin films were thermally deposited onto glass substrate. The CdCl2 layer was deposited onto CdS surface. These followed by annealing for different duration times to modify the surface and interface of the junction. The diffraction patterns showed that the intensity of the peaks increased with the CdCl2/annealed treatment, and the grain sizes are increased after CdCl2/annealed treatment