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A material corrosion test loop (“Lobo Lead Loop”) has been established at the University of New Mexico to investigate the compatibility of structural materials with flowing molten lead. The project aims to prequalify materials for Versatile Test Reactor (VTR) testing and support the development of computational models of flow accelerated corrosion in molten lead. The Lobo Lead Loop is designed to operate at high temperatures up to 700 °C and high mean flow velocities reaching 3 m/s within the specimen holder channels. Numerical simulations are utilized to design loop components with performance that allows for achieving the operation targets. Specimen holders are designed for (a) multi-material testing at 3 m/sec, (b) multi-velocity testing, (c) shear stress testing, and (d) high temperature (≥600 °C) testing at low mass flow rates. The computational fluid dynamics models used are shown to produce results in agreement with experimental data for flow in pipes. The models are then used in parametric analyses to identify parameters of importance to specimen holder design and computation of pressure losses for flows along smooth and rough specimen walls. Specimen holder designs for the purposes outlined are presented along with performance curves. The maximum achievable flow rate is estimated based on the intersection of the pump performance curve with the system curve.

Sculpting a flat patch of membrane into an endocytic vesicle requires curvature generation on the cell surface, which is the primary function of the endocytosis machinery. Using super-resolved live cell fluorescence imaging, we demonstrate that curvature generation by individual clathrin-coated pits can be detected in real time within cultured cells and tissues of developing organisms. Our analyses demonstrate that the footprint of clathrin coats increases monotonically during the formation of pits at different levels of plasma membrane tension. These findings are only compatible with models that predict curvature generation at the early stages of endocytic clathrin pit formation. We also found that CALM adaptors associated with clathrin plaques form clusters, whereas AP2 distribution is more homogenous. Considering the curvature sensing and driving roles of CALM, we propose that CALM clusters may increase the strain on clathrin lattices locally, eventually giving rise to rupture and subsequent pit completion at the edges of plaques.

A new test loop made out of FeCrAl based oxide dispersion strengthened steel (ODS) MA956 is established at the University of New Mexico (UNM). The facility will support Versatile Test Reactor (VTR) program’s cartridge design out-of-pile to explore solutions for material compatibility issues of Lead Cooled Fast Reactors (LFRs). The loop is capable of operating up to 700 °C. While the flow rate in the MA956 pipe can reach up to 1 m/s, the specimen holders are designed to allow flow rates on the test specimens to reach 3 m/s. Numerical modeling is utilized to guide the experiments and assess the sensitivity to different design and operation parameters. In addition to the materials testing, a variety instrumentation needed for the operation of the reactors as well thermal hydraulics studies through a heat exchanger is also considered.

Sculpting a flat patch of membrane into an endocytic vesicle requires curvature generation on the cell surface, which is the primary function of endocytic protein complexes. The mechanism through which membrane curvature is imposed during formation of clathrin-coated vesicles is an ongoing controversy. Using super-resolved live cell fluorescence imaging, we demonstrate that curvature generation by clathrin-coated pits can be detected in real time within cultured cells and tissues of developing metazoan organisms. We found that the footprint of clathrin coats increase monotonically during formation of curved pits at different levels of plasma membrane tension. Our findings are only compatible with models that predict curvature generation at early stages of endocytic clathrin-coated pit formation. Therefore, clathrin-coated vesicle formation does not necessitate a dynamically unstable clathrin lattice that would allow an abrupt flat-to-curved transition.SummaryEndocytic clathrin coats acquire curvature without a flat-to-curved transition that requires an extensive reorganization of the clathrin lattice.

The radiation dose affects health when it causes changes in the cells of the human body. The risk of harmful health effects generally increases with the amount of radiation absorbed. In this work, the annual internal radiation doses have been measured in seven building for Ishik University in Erbil city, using active technique (survey radiation dosimeter) during two seasons- winter and spring. The highest average values of exposure radiation dose were found in dentistry faculties for winter season (0.699 ± 0.09 μSv/h) and lowest values were found in Student dormitory (boys) for summer season (0.109± 0.05 μSv/h). The highest average exposure radiation dose was found in the basement floor for all buildings compare with the ground, first, second and third floors. The rate radiation dose in different type rooms depended on the ventilation rate, leakage dose and age of building. The annual exposure dose was considered as the main factor to assessment risks of that leakage on the health of workers and student.