Bibliographic reports on the electric conductivity of pure homoionic montmorillonite at low water content were analyzed in order to stress a general behavior of conductivity. At low water content, the conductivity is ...Bibliographic reports on the electric conductivity of pure homoionic montmorillonite at low water content were analyzed in order to stress a general behavior of conductivity. At low water content, the conductivity is attributed to a mechanism of charge transport involving protons due to the influence of the electric field of the exchangeable cations on water molecules at the solvation shell. Conductivity was analyzed in relation with the polarizing power （ionic potential） of the exchangeable cations and with the influence of the connectivity within samples. The general conclusion stressed is that the connectivity due to the association between 2：1 unit layers （clay fabric） is the main factor on the experimental or ＂macroscopic＂ electric conductivity of pure homoionic montmorillonite at low water content. Considerations on the experimental conditions of different bibliographic reports were also made. The conclusion and the considerations made on experimental conditions are a good starting point for future researches on electric conductivity ofhomoionic montmorillonite at low water content.展开更多
This work continues the approach of one of our topics relating to a MOM-THP （metal on metal-total hip prostheses） with self-directed movement balls. Experiments revealed a certain seizure in some strain conditions. ...This work continues the approach of one of our topics relating to a MOM-THP （metal on metal-total hip prostheses） with self-directed movement balls. Experiments revealed a certain seizure in some strain conditions. Laboratory trials for balls/plane Hertzian contacts have been restarted in order to determine seizure behaviour depending on the roughness of the flat area. The trials have been carried out in BSF （body simulated fluid） lubrication conditions, much closer to the real operating conditions up against the initial tests with distilled water. Seizure burdens to different loadings and contact surfaces roughness influence over the seizure burden have been determined. Even though the minimum value of the wear must be the same with the minimum value of the surfaces roughness, given the experimental conditions, it came out from the trials results on wear that the lowest level of wear is acquired at a certain value of roughness, not at the lowest level of roughness.展开更多
文摘Bibliographic reports on the electric conductivity of pure homoionic montmorillonite at low water content were analyzed in order to stress a general behavior of conductivity. At low water content, the conductivity is attributed to a mechanism of charge transport involving protons due to the influence of the electric field of the exchangeable cations on water molecules at the solvation shell. Conductivity was analyzed in relation with the polarizing power （ionic potential） of the exchangeable cations and with the influence of the connectivity within samples. The general conclusion stressed is that the connectivity due to the association between 2：1 unit layers （clay fabric） is the main factor on the experimental or ＂macroscopic＂ electric conductivity of pure homoionic montmorillonite at low water content. Considerations on the experimental conditions of different bibliographic reports were also made. The conclusion and the considerations made on experimental conditions are a good starting point for future researches on electric conductivity ofhomoionic montmorillonite at low water content.
文摘This work continues the approach of one of our topics relating to a MOM-THP （metal on metal-total hip prostheses） with self-directed movement balls. Experiments revealed a certain seizure in some strain conditions. Laboratory trials for balls/plane Hertzian contacts have been restarted in order to determine seizure behaviour depending on the roughness of the flat area. The trials have been carried out in BSF （body simulated fluid） lubrication conditions, much closer to the real operating conditions up against the initial tests with distilled water. Seizure burdens to different loadings and contact surfaces roughness influence over the seizure burden have been determined. Even though the minimum value of the wear must be the same with the minimum value of the surfaces roughness, given the experimental conditions, it came out from the trials results on wear that the lowest level of wear is acquired at a certain value of roughness, not at the lowest level of roughness.
