Sharif Digital Repository

Natural boron consists of two stable isotopes, mass 10 (19.3%) and mass 11 (80.7%). 10B isotope has a large thermal neutron capture cross-section and it therefore, used widely in such aspects as modern industry, military equipment, medical science and so on. specially the demand of atomic energy industry for the boron isotope is increased severely. So the separation of 10B from natural boron has received very wide attention at present. There are many kinds of methods on the boron isotopes separation, such as chemical exchange reaction and distillation in boron trifluoride method, ion exchange in boric acid solution method, counter current recycle membrane cascades in boron trifluoride... 

Natural boron includes two stable isotopes 10B and 11B with 19.3 and 80.7 weight percent respectivley.10B isotope has a high thermal neutron absorption cross section. So isotope 10B material is suitable for making atomic reactor control rods. Other and even more important applications of 10B are in disclosing neutrons in order to measure neutron reactors fluxes and also are in nuclear physics laboratories and medical radiation. This isotope also is used in the pharmaceutical and the military industries. There are several methods for separating boron isotopes. Among the distillation methods, thermal diffusion of BF3, distillation of BF3, distillation of methyl borate, boric acid distillation... 

Solar distillation is a comparatively easy treatment of brackish (i.e. contain dissolved salts) water supplies. Distillation is a well-known process, which may be used for water filtration utilizing heating sources. In this research, the solar distillation set with heat-pipes was made and tested in 18 months.At the first step, during four days, the pipes were filled with some water to certain height every day while temperature and produced water were estimated. At the second step, the vacuum pipes were filled with some oil and tested for 4 different heights within 4 days; and in final steps, aluminum chips, washing wire and metal foam were shaded into the tank then tested by an optimum water... 

The use of magnetic compounds for drug delivery and magnetic imaging has been studied in many studies. The easy use of magnetic particles makes them widespread. By applying a magnetic field, the particles reach the desired position and return to the original state by cutting off the field. The use of these magnetic materials in the nanoscale also adds other benefits, including: convenient and rapid transfer of nanoparticles, rapid repulsion of the kidneys, reducing the risk of overdose, etc. In recent years, the use of quantum dots for the diagnosis and treatment of tumors has attracted much attention. The use of hybrid quantum dots and magnetic nanoparticles can incorporate the desired... 

Nowadays, neural networks are used as the main method in most machine learning applications. But research has shown that these models are vulnerable to adversarial attacks imperceptible changes to the input of neural networks that cause the net- work to be deceived and predict incorrectly. The importance of this issue in sensitive and security applications of neural networks, such as self-driving cars and medical diagnosis systems, becomes much higher. In recent years, many researches have been done in the field of making neural net- works robust against this threat, but in most of them, higher robustness has been provided on the basis of larger and more complex models. Few researches have... 

Cryogenic distillation of air is the only method of large-scale production of high-purity oxygen and nitrogen. The falling film column, due to its lower pressure drop and higher heat transfer, is gaining attention. In this method, the heat and mass transfer take place simultaneously on a vertical wall. The present study aims at providing a numerical framework based on a finite volume approach to simulate the falling film distillation column, focusing on the high-pressure column of an air separation unit. Due to the heat integration, filmwise condensation is expected to happen on the surface of the column. An innovative sub-model is developed to evaluate condensation heat transfer...