RESUMO
Aluminum is lightweight durable, versatile, non-toxic, and corrosion-resistant surface, which makes aluminum a perfect material for improving the corrosion properties of aluminum-carbon steel which is important in the radiation domain. In this study, six carbon steel alloys doped with different aluminum concentrations were studied and compared with the standard austenite stainless steel AISI316L. Different parameters for shielding and dosimetry such as mass attenuation coefficient, tenth value layer, mean free path, equivalent effective atomic and electronic numbers were calculated using WinXCom, while the exposure absorption buildup factors, thermal and fast neutron removal cross-sections were calculated using MCNPX and the effective conductivity was calculated using Phy-X/PSD program. Regarding the radiation shielding performance, the addition of aluminum to the carbon alloys has a significant influence on the shielding parameters. The results suggest that the addition of aluminum to the carbon steel alloys would improve its shielding properties so that it is a good result to be used in the field of dosimetry and radiation shielding.
RESUMO
In this work, Cobalt-free alloys are prepared as a capsule in which radioactive waste is placed for disposal, and this is a preventive measure to rid the environment of radioactive waste and bury it deep in the earth in a capsule. So, the buildup factor was measured for 1-5-10-40 MFP. The mechanical properties (hardness and toughness) of the processed samples were studied. The hardness was calculated by the Vickers hardness test additionally; the tolerance process was carried out using concentrated chloride acid for 30 days and NaCl 3.5% for 30 days for the studied samples. In this work the resulted developed alloys are resistant to stainless steel 316 L and therefore the alloys are a suitable material in the nuclear field as a container for burying and disposing of waste.
RESUMO
By using an electro-slag re-melting procedure, new shielding steel alloys with varying chromium concentrations ranging from 2 to 18%, and a reduced nickel content of roughly 12% were developed. The mass attenuation µm, mean free path (MFP), effective atomic number Zeff, and electron density Neff, the energy buildup factor (EBF), and the energy absorption buildup factor (EABF) were calculated for the new developed steel alloys by using Phy-X/PSD software over the photon energy range (0,015-15 MeV). Furthermore, using the NGCAL online software, the macroscopic effective neutron removal cross-sections (ΣR) for 25.4 meV thermal neutrons, 4 MeV fast neutrons, and 10 MeV fast neutrons were determined. All cobalt-free steel prepared samples (S1, S2, S3, S4, and S5) were found to have lower mean free path (MFP) and half-value layer (HVL) values, as well as greater macroscopic effective neutrons removal cross section (ΣR) values, than their estimated equivalents for both carbon steel and stainless steel. Furthermore, based on the estimated values for the mean free path (MFP), the half-value layer (HVL), and the effective neutrons removal cross section (R), sample S5 with the greatest chromium content (17.68%) is shown to be a good candidate for gamma shielding rather than neutron shielding.
RESUMO
Ornithobacterium rhinotracheale (ORT), a bacterium causing respiratory tract infection, has led to a significant problem in the intensive poultry production in Egypt. Polymerase chain reaction-amplified 784-bp specific ORT DNA fragments were found in 7 ORT isolates from lungs, air sacs, and tracheas of commercial broilers or layers in Egypt in 2015. The objective of this study was to investigate the role of the live variant IBV 4/91 with ORT infection. A total of 120 14-d-old broiler chickens (Cobb 500) were equally divided into 4 groups for experimental infection in a complete randomized design. Group 1 was infected with ORT strain and live infectious bronchitis vaccine (IBV 4/91) simultaneously; group 2 was infected with the bacterial strain alone; group 3 was vaccinated only with IBV 4/91, and group 4 was the non-vaccinated and non-infected control group. The respiratory signs, post-mortem lesions (tracheitis and pneumonia) and histopathological findings of lungs, trachea, and air sacs in the experimentally infected broiler chickens appeared to be more prominent in the chickens of group 1 than group 2. With respect to body weight, weight gain, feed conversion rate, and Ornithobacterium re-isolation, there was a difference (P ≤ 0.05) among the chickens of group 1 and the other groups. This reveals that the use of live infectious bronchitic vaccines, which is a common practice in the local Egyptian field of production, may concomitantly increase the pathogenicity of ORT in broiler chickens.
