The Growth Kinetics of RhizoctoniasolaniAfter 1 MeV Electron Irradiation

Crops, especially potatoes, are prone to a wide range of fungal, viral and bacterial diseases, including black scurf caused by Rhizoctoniasolani. This study focused on the radiation treatment of the phytopathogenic fungus RhizoctoniasolaniKuhn, grown from sclerotium irradiated with 1 MeV electrons in the dose range from 20 to 4500 Gy. The doses absorbed by the sclerotia were determined using computer simulation. The growth of the fungus samples was monitored after 24, 48, 72, and 96 hours from the time of seeding. It was found that the dependence of the radial growth velocity of R. solani on the time after irradiation with doses ranging from 20to 1800 Gywas nonlinear. Irradiation at a dose over 4500 Gyled to complete suppression of the germination of R. solani sclerotia. Keywords: radiation treatment, electron radiation, radiation dose, sclerotia of Rhizoctoniasolani, Kuhn, radial velocity of growth

Induced electron radiation effect on the performance of inter-satellite optical wireless communication

This paper provides the details of a study on the effects of electron radiation on the Performance of Inters-satellite Optical Wireless Communication (IsOWC). Academia and industry focus on solutions that can improve performance and reduce the cost of IsWOC systems. Spacecraft, space stations, satellites, and astronauts are exposed to an increased level of radiation when in space, so it is essential to evaluate the risks and performance effects associated with extended radiation exposures in missions and space travel in general. This investigation focuses on LEO, especially in the near-equatorial radiation environment. Radiation experiments supported with simulations have made it possible to obtain and evaluate the electron radiation impact on optoelectronics at the device level and system level performances. The electron radiation has induced a system degradation of 70%. This result demonstrates the importance of such an investigation to predict and take necessary and suitable reliable quality service for future space missions.

Comparative Study of γ- and e-Radiation-Induced Effects on FBGs Using Different Femtosecond Laser Inscription Methods

This work presents an extensive, comparative study of the gamma and electron radiation effects on the behaviour of femtosecond laser-inscribed fibre Bragg gratings (FBGs) using the point-by-point and plane-by-plane inscription methods. The FBGs were inscribed in standard telecommunication single mode silica fibre (SMF28) and exposed to a total accumulated radiation dose of 15 kGy for both gamma and electron radiation. The gratings’ spectra were measured and analysed before and after the exposure to radiation, with complementary material characterisation using Fourier transform infrared (FTIR) spectroscopy. Changes in the response of the FBGs’ temperature coefficients were analysed on exposure to the different types of radiation, and we consider which of the two inscription methods result in gratings that are more robust in such harsh environments. Moreover, we used the FTIR spectroscopy to locate which chemical bonds are responsible for the changes on temperature coefficients and which are related with the optical characteristics of the FBGs.

Influence of electron radiation on the physical and mechanical properties of a nonwoven fabric made using Spunlace technology

The effect of electron radiation on the physical and mechanical properties of Sontara nonwoven fabric produced using spunlace technology has been studied. The initial raw material for the manufacture of materials using this technology, as a rule, are viscose, polyester, polypropylene and cellulose fibers. Such nonwovens are highly breathable and are therefore used in disposable surgical gowns and suits. Since radiation can be used to sterilize disposable surgical gowns, it is important to assess the resistance to ionizing radiation. It was found that the Sontara brand material is resistant to the effects of ionizing radiation - the physical and mechanical characteristics of the material (breaking load and relative elongation) in the longitudinal and transverse directions of the web do not significantly change when irradiated with absorbed doses up to 60 kGy. It should also be noted that a cloth with a basis weight of 68 g/m2 has a significant smell of strength after radiation sterilization.

Radioterapia intraoperatoria de electrones en cáncer de mama. Experiencia en Venezuela.

Objective: To evaluate the evolution of patients treated with intraoperative electron radiotherapy by Group J Soteldo, in Hospital de Clínicas Caracas. Methods: Descriptive observational study. We included 18 patients treated with intraoperative electron radiation therapy between April 2017 and July 2018. Medical records were reviewed to study the evolution, patients who had not returned in the last six months were contacted by telephone. Intraoperative electron radiation therapy was applied during the same surgical act, at a dose of 21 Gy, after the tumor was removed from the affected breast, at the level of the tumor bed. Results: The mean age was 54.5 years, the mean tumor size was 2.48 cm. Twelve patients had cancer in the right breast (66.7%) and six in the left (33.3%). Nine cases (50%) were Luminal B; 15 patients had infiltrating ductal carcinoma (83.3%), 13 (72.2%) had a negative axilla. Six patients (33.3%) underwent axillary dissection up to the third level and 12 (66.7%) had a sentinel node. Five patients (27.8%) received a single dose of intraoperative electron radiation therapy and 13 (72.2%) received booster doses. No patient has had a relapse of the disease or serious adverse effects associated with radiation therapy. Conclusion: The use of intraoperative electron radiation therapy was an effective and well tolerated treatment in this group of patients. It is not a commonly used treatment in Venezuela. Key words: Breast cancer, Radiotherapy, Electrons.

Influence of Gamma and Electron Radiation on the Strength Characteristics of Nonwoven SMS Materials Based on Polypropylene

Radiation sterilization is widely used to sterilize nonwoven SMS medical products. SMS materials have improved filtering and barrier properties, low bacteriopermeability and, due to these properties, are indispensable for medicine. They are used to make such important health care products as disposable surgical clothing and underwear. As a result of the research carried out, the effect of gamma and electron radiation, in the range of absorbed doses from 15 to 25 kGy, on the strength characteristics of nonwoven SMS materials based on polypropylene with a surface density of 35, 40, 50 g/cm2 was studied. It has been established that the strength characteristics (tensile strength, tensile strength, and tear strength) of nonwoven materials decrease after exposure to ionizing radiation. The higher the density of the material, the more its characteristics decrease after radiation sterilization. It was also found that gamma radiation, due to its nature, has a stronger effect on nonwoven materials based on polypropylene, and leads to a stronger decrease in strength characteristics. In general, for products sterilized by ionizing radiation and made from SMS materials, it is important to control the strength characteristics, primarily, the tensile strength in the transverse direction of the web stuff.