[en] In France, the deep underground nuclear waste repository consists of a natural barrier (in an argillaceous rock named argillite), associated to artificial barriers, including plugs of swelling clay (bentonite)-sand for tunnel sealing purposes. The main objective of this thesis is to assess the sealing efficiency of the bentonite-sand plug in contact with argillite, in presence of both water and gas pressures. To assess the sealing ability of partially water-saturated bentonite/sand plugs, their gas permeability is measured under varying confining pressure (up to 12 MPa). It is observed that tightness to gas is achieved under confinement greater than 9 MPa for saturation levels of at least 86-91%. We than assess the sealing efficiency of the bentonite-sand plug placed in a tube of argillite or of Plexiglas-aluminium (with a smooth or a rough interface). The presence of pressurized gas affects the effective swelling pressure at values P_g_a_s from 4 MPa. Continuous gas breakthrough of fully water-saturated bentonite-sand plugs is obtained for gas pressures on the order of full swelling pressure (7-8 MPa), whenever the plug is applied along a smooth interface. Whenever a rough interface is used in contact with the bentonite-sand plug, a gas pressure significantly greater than its swelling pressure is needed for gas to pass continuously. Gas breakthrough tests show that the interface between plug/argillite or the argillite itself are two preferential pathways for gas migration, when the assembly is fully saturated. (author)

[en] We show that in contrast to the recent suggestion of Babu and Mathur, the Zee model actually cannot provide the required amount of Majorana neutrino precession for the Okun-Voloshin-Vysotsky solution to the solar neutrino problem. (orig.)

[en] The cosmological constraint together with the information obtained from the supernova could be used to give a lower bound on the mass of unstable neutrinos. It is shown that if the only viable channel for the unstable neutrino decay is through three lighter neutrinos, the mass of this particle should be heavier than about 500 eV. (orig.)

[en] The electric dipole moment (EDM) of the electron is calculated in the SU(2)sub(L)xSU(2)sub(R)xU(1)sub(B-L) model. The value is shown to be less than 21x10^-26 e.cm using only the standard limit of the mass of the right-handed gauge boson W₂. In a one-parameter model due to Chang fitted to CP violation in K⁰ decay, the value is 10^-29 e.cm. Physical Higgs contributions to this effect are also examined. (orig.)

[en] We discuss the prospect and difficulties of having a neutrino with a large magnetic moment and a naturally small mass in the SU(3)_LxU(1) model. (orig.)

[en] By using noise analysis technology, experiments have been done on the basis of four combination situations: when the collision of mimic loose parts took place in air or in water respectively, while the upper and lower edges of the collided steel plates are both air or water and air. The influence of production and propagation of collision wave by water are researched. The time shape and average power spectrum of collision wave are determined. Through the comparison and analysis of experiments result, it can be concluded that when the collision took place in water, the maximum amplitude of responding accelerate, the speed of decline and the distribution of average power spectrum are obviously different from that of in air. The result of research can be stated that when the loose parts monitoring in PWR the collision model provided by American scholar W.H.Hoppmann II has some errors

[en] The acidic in-situ leaching of uranium has a strict demand on the geology and hydrogeology of the deposit. The results of a field test on acidic in-situ leaching of uranium in some deposit are described in this article, based on analysis of the unfavourable influences induced by the carbonate clay minerals and the mineralized degree of ground water. (authors)

[en] A reasonable extension of the superweak theory for the K⁰ system allows the possibility that the B⁰-anti B⁰ mass difference is primarily due to a superweak interaction. In contrast to the standard model this possibility does not require the B_s-anti B_s mass difference to be greater than B⁰-anti B⁰. With this explanation the CP violation associated with B⁰-anti B⁰ mixing is likely to be much smaller than in the standard model. (orig.)

[en] Spontaneous CP violation can occur in the SU(2)_L x U(1)_γ model if there are two Higgs doublets. This model is analyzed accepting standard constraints on the Higgs masses. CP violation occurs both as the result of Higgs boson exchange and the usual KM mechanism of gauge boson exchange. The main contribution to ε comes from superweak Higgs boson exchange. The value of ε'/ε is found to be between 10^-3 and 10^-5 arising both from Higgs boson exchange and the KM mechanism. The neutron electric dipole moment is found to be of order 10^-26 e.cm arising mainly from the charged Higgs boson exchange. As a special feature of this model the muon longitudinal polarization in the decay K_L → anti μμ is found between the order of unity and 10^-2 arising from the flavor changing neutral Higgs boson exchange. (orig.)

[en] A large magnetic moment or transition moment of the neutrino have been suggested as explanations for the solar neutrino puzzle. These scenarios have the attractive feature of incorporating an anticorrelation of the solar neutrino flux with sun spot activity. Recently it has been claimed that the 1987 supernova results put a severe bound on the neutrino magnetic moment, allowing only values that are too small to account for the solar neutrino flux depletion. Here we show that this bound does not apply to the transition magnetic moment of Majorana neutrinos. Other laboratory, astrophysical and cosmological bounds are also discussed. (orig.)