Mohr-Coulomb Failure Condition and the Direct Shear Test Revisited

An alternative critical plane orientation is proposed in the Mohr-Coulomb failure criterion for soils with an extreme property. Parameter identification from the direct shear test is extended to incude the lateral normal stress.

Incidence of Leukemia, Lymphoma, and Multiple Myeloma in Czech Uranium Miners: A Case–Cohort Study

OBJECTIVE: Uranium miners are chronically exposed to low levels of radon and its progeny. We investigated whether radon exposure is associated with increased incidence of leukemia, lymphoma, or multiple myeloma in this population. DESIGN: We conducted a retrospective case–cohort study in 23,043 uranium miners and identified a total of 177 incident cases of leukemia, lymphoma, and myeloma. Detailed information on occupational radon exposure was obtained for the cases and a randomly selected subcohort of 2,393 subjects. We used the proportional hazards model with power relative risk (RR) function to estimate and test the effects of cumulative radon exposures on incidence rates. RESULTS: Incidence of all leukemia combined and chronic lymphocytic leukemia (CLL) alone was positively associated with cumulative radon exposure. The RR comparing high radon exposure [110 working level months (WLM); 80th percentile] to low radon exposure (3 WLM; 20th percentile) was 1.75 [95% confidence interval (CI), 1.10–2.78; p = 0.014] for all leukemia combined and 1.98 (95% CI, 1.10–3.59; p = 0.016) for CLL. Myeloid leukemia and Hodgkin lymphoma were also associated with radon, but RRs were not statistically significant. There was no apparent association of radon with either non-Hodgkin lymphoma or multiple myeloma. Exposure to radon and its progeny was associated with an increased risk of developing leukemia in underground uranium miners. CLL, not previously believed to be radiogenic, was linked to radon exposure

Assessment of the historical, architectural and structural value of masonry arch road bridges

The aim of the methodology is to become a tool for proper decision-making and care of historic masonry arch bridges serving our transport network and to contribute to their preservation. It should help to identify and correctly assess their historical significance and their cultural, structural and heritage value. To correctly guide the process of their professional evaluation and proposals for their maintenance and restoration. Demonstrate the possibilities of their correct assessment in terms of their structural-technical condition and structural-mechanical action, enabling their preservation in reliable operation in traffic. By means of these correct procedures, it would like to establish general confidence in their design principles and craftsmanship and to translate this into the design of reconstruction and restoration interventions or appropriate adaptations with modern sensitive additions. It is intended to enable the legitimate existence and functioning of these irreplaceable buildings for our present and future