The Mu2e Transport Solenoid consists of 52 coils arranged in 27 coil modules that form the S-shaped cold mass. Each coil is wound from Al-stabilized NbTi superconductor. The coils are supported by an ...external structural aluminum shell machined from a forged billet. Most of the coil modules house two coils, with the axis of each coil oriented at an angle of approximately 5° with respect to each other. The coils are indirectly cooled with LHe circulating in tubes welded on the shell. In order to enhance the cooling capacity, pure aluminum sheets connect the inner bore of the coils to the cooling tubes. The coils are placed inside the shell by the means of a shrink-fit procedure. A full-size prototype, with all the features of the full assembly, was successfully manufactured in a collaboration between INFN Genova and Fermilab. In order to ensure an optimal mechanical prestress at the coil-shell interface, the coils are inserted into the shell through a shrink-fitting process. We present the details of the prototype with the design choices as validated by the structural analysis. The fabrication steps are described as well.
Test Results of the LARP Nb3Sn Quadrupole HQ03a DiMarco, J.; Ambrosio, G.; Anerella, M. ...
IEEE transactions on applied superconductivity,
06/2016, Letnik:
26, Številka:
4
Journal Article
Recenzirano
Odprti dostop
The U.S. LHC Accelerator Research Program (LARP) has been developing Nb 3 Sn quadrupoles of increasing performance for the high-luminosity upgrade of the large hadron collider. The 120-mm aperture ...high-field quadrupole (HQ) models are the last step in the R&D phase supporting the development of the new IR Quadrupoles (MQXF). Three series of HQ coils were fabricated and assembled in a shell-based support structure, progressively optimizing the design and fabrication process. The final set of coils consistently applied the optimized design solutions and was assembled in the HQ03a model. This paper reports a summary of the HQ03a test results, including training, mechanical performance, field quality, and quench studies.
Category:
Arthroscopy; Ankle
Introduction/Purpose:
The ankle arthroscopy has many advantages compared to open surgery and it is possible to access the ankle anteriorly and posteriorly. The ...pathologies localized in the anterior and posterior aspects of the ankle may coexist and demand the combination of these approaches. The objective is to describe the anterior and posterior ankle arthroscopic access, keeping the patient in prone position, reducing the risks of contamination, surgical time and favoring the operative strategy.
Methods:
Patients diagnosed with chronic ankle instability and posterior ankle impingement, who failed conservative treatment for 3 months were selected. These patients were positioned in ventral decubitus and performed arthroscopic resection of posterior impingement followed by a Brostrom-Gould procedure, without decubitus change.
Results:
Patients were positioned in prone position, with spinal block performed and application of pneumatic tourniquet on the thigh. The posterior arthroscopic approach was first stablished through the posterolateral and posteromedial portals. The Os Trigonum could be identified and then removed. Maintaining the decubitus, the anterior approach was performed through 90° knee flexion, enabling the creation of the anteromedial and anterolateral portals. At this time, the lateral ankle instability could be treated by a Broström-Gould procedure in a upside down manner.
Conclusion:
The anterior and posterior approach by arthroscopy may provide a faster rehabilitation associated with lesser soft tissue trauma and lesser post-operative comorbities compared to open techniques. Also the combination of these approaches without decubitus change may reduce the surgery time and contamination risks. Disadvantages should also be considered and these includes the risk of compartimental syndrome and its severe complications. In addition, the arthroscopic images can be difficult to understand at first and the Broström-Gould procedure performed in a upside down manner will require a experienced staff in the surgery.
Protection heaters are essential elements of a quench protection scheme for high-field accelerator magnets. Various heater designs fabricated by LARP and CERN have been already tested in the LARP ...high-field quadrupole HQ and presently being built into the coils of the high-field quadrupole MQXF. In order to compare the heat flow characteristics and thermal diffusion timescales of different heater designs, we powered heaters of two different geometries in ambient conditions and imaged the resulting thermal distributions using a high-sensitivity thermal video camera. We observed a peculiar spatial periodicity in the temperature distribution maps potentially linked to the structure of the underlying cable. Two-dimensional numerical simulation of heat diffusion and spatial heat distribution have been conducted, and the results of simulation and experiment have been compared. Imaging revealed hot spots due to a current concentration around high curvature points of heater strip of varying cross sections and visualized thermal effects of various interlayer structural defects. Thermal imaging can become a future quality control tool for the MQXF coil heaters.
In a randomized trial, 5988 patients with heart failure with preserved ejection fraction were assigned to receive either empagliflozin or placebo in addition to usual therapy. At a median of 26 ...months, the empagliflozin group had a lower incidence of cardiovascular death or hospitalization for heart failure than the placebo group.
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