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Reinforced concrete floating caissons are widely used for the construction of vertical breakwaters and gravity quay walls. This paper describes the caisson construction methods that are used most frequently in Spanish port structures, especially casting on floating dry docks. Determining factors in the selection of caisson type for breakwaters rely on technical and economic considerations. Environmental considerations emphasise the use of caissons when compared to alternatives that require large quantities of quarry stone materials such as rubble mound breakwaters. The main limiting factors are high stresses induced on the sea floor and the presence of complex dynamic wave-structure-soil interaction phenomena. Generalisation in the application of soil improvement techniques in the sea floor will extend the application of floating reinforced concrete caissons to soft-soil areas, which are very common in Spanish ports. There are also research programmes under development focusing on improving of the functional features of vertical wall structures, mainly determined by their high reflection. Technical and economic optimisation of marine structures based on floating reinforced concrete caissons is today an essential trend in the field of port structures in Spain. [ABSTRACT FROM AUTHOR]

Background: Soft tissue sarcomas (STS) are rare malignant tumors of mesenchymal origin. They are associated with genetic and environmental risk factors. Their clinical manifestations are nonspecific, requiring a high level of suspicion. The first-line treatment is surgical. Positive margins are the only independent predictor of local recurrence and worse survival rates. Strict follow-up is recommended due to its high recurrence rate., Aim: Analyze the casuistry of STS treated with curative intent by the head and neck surgery team at the Sótero del Río Hospital (HSR) at Santiago, Chile between 2013 and 2023., Methods: A retrospective, descriptive study of patients with STS managed by the HSR head and neck surgery team. Clinical presentation, diagnostic and therapeutic tools, and oncological results are analyzed., Results: 26 patients were included, 84.6% female, with an average age of 61.7 years. Only 30.8% presented identifiable risk factors. The most common histology was undifferentiated pleomorphic sarcoma (26.9%), and the predominant location was extremities (46.2%). 77.8% of head and neck sarcomas and 58.8% of trunk and extremity sarcomas occurred in advanced stages. Disease-free survival was 66.6%; 68.2% in patients with negative surgical margins, and 60.0% in positive margins at five years., Conclusions: STS is an infrequent pathology. This study corresponds to the first retrospective research on STS in Chile. We require establishing a specialized multidisciplinary team to optimize the management and follow-up of STS patients.

A groundwater activation model was developed for use in designing the accelerators at the Superconducting Super Collider Laboratory. This model is based on the concept of a 4-m-thick "activation zone" surrounding the accelerator enclosure, which contains over 99% of the soil activation caused by beam losses. Empirical shielding formulae based on computer simulations indicate that the soil activation in the activation zone decreases exponentially with distance from the tunnel enclosure. From this assumption, the average activation in the activation zone is derived. It is shown that the average activity concentration in the activation zone is equal to the activity concentration 1 m from the accelerator enclosure. The activation concentration in the water averaged over the volume of the activation zone is compared to the drinking water standards. The goal of this model is to meet the drinking water regulatory standards by averaging the activation in the activation zone. Groundwater activation concentrations have been calculated for the Super Collider utilizing experimental measurements of production cross sections and leachability factors. Comparison is made to the groundwater activation criterion for both routine and accidental beam losses.