82 research outputs found

    In situ micro gas tungsten constricted arc welding of ultra-thin walled 2.275 mm outer diameter grade 2 commercially pure titanium tubing

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    Ultra-thin walled cooling tubes for heat exchangers and condenser units have applications in multiple high-value manufacturing industries. Grade 2 commercially pure titanium (CP-2 Ti) requires far less mass to achieve the same mass flow handling abilities as stainless steel tubing yet it is more challenging to join, particularly at wall thicknesses less than 500 Όm (termed ultra-thin walled tube). This paper presents a single-pass joinery method that produces reliable welds on 2.275 mm outer diameter (OD), 160 ± 10 Όm wall thickness tubing with a service life of 20 of more years. This is achieved through an automated orbital gas tungsten constricted arc welding (GTCAW) process incorporating enveloping low-mass sleeves used in tandem with a buttressing internal gas pressure to support the molten metal and maintain consistent internal diameter inside the tube. The industrial applicability is demonstrated through the production of a 1:1 scale mock-up of a fixed geometry CO2 cooling circuit for a next-generation particle detector. The tensile strengths of the joints, 403.8 ± 4.2 MPa, exceed the tensile strength of the parent CP-2 Ti

    The electromagnetic calorimeter for the T2K near detector ND280

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    The T2K experiment studies oscillations of an off-axis muon neutrino beam between the J-PARC accelerator complex and the Super-Kamiokande detector. Special emphasis is placed on measuring the mixing angle Ξ 13 by observing Îœ e appearance via the sub-dominant ΜΌ Îœ e oscillation and searching for CP violation in the lepton sector. The experiment includes a sophisticated, off-axis, near detector, the ND280, situated 280 m downstream of the neutrino production target in order to measure the properties of the neutrino beam and to understand better neutrino interactions at the energy scale below a few GeV. The data collected with the ND280 are used to study charged- and neutral-current neutrino interaction rates and kinematics prior to oscillation, in order to reduce uncertainties in the oscillation measurements by the far detector. A key element of the near detector is the ND280 electromagnetic calorimeter (ECal), consisting of active scintillator bars sandwiched between lead sheets and read out with multi-pixel photon counters (MPPCs). The ECal is vital to the reconstruction of neutral particles, and the identification of charged particle species. The ECal surrounds the Pi-0 detector (PØD) and the tracking region of the ND280, and is enclosed in the former UA1/NOMAD dipole magnet. This paper describes the design, construction and assembly of the ECal, as well as the materials from which it is composed. The electronic and data acquisition (DAQ) systems are discussed, and performance of the ECal modules, as deduced from measurements with particle beams, cosmic rays, the calibration system, and T2K data, is described.© 2013 IOP Publishing Ltd and Sissa Medialab srl.The ECal detector has been built and is operated using funds provided by the Science and Technology Facilities Council U.K. Important support was also provided by the collaborating institutions. Individual researchers have been supported by the Royal Society and the European Research Council

    First muon-neutrino disappearance study with an off-axis beam

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    We report a measurement of muon-neutrino disappearance in the T2K experiment. The 295-km muon-neutrino beam from Tokai to Kamioka is the first implementation of the off-axis technique in a long-baseline neutrino oscillation experiment

    Eye Manifestations of Shprintzen–Goldberg Craniosynostosis Syndrome: A Case Report and Systematic Review

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    Shprintzen–Goldberg craniosynostosis syndrome (SGS) is a rare autosomal dominant condition that was first documented in literature in 1982. The disorder is caused by pathogenic variants in the proto-oncogene SKI gene, a known suppressor of TGF-ÎČ activity, located on chromosome 1p36. There is considerable phenotypic overlap with Marfan and Loeys–Dietz syndromes. Common clinical features of SGS include craniosynostosis, marfanoid habitus, hypotonia, dysmorphic facies, cardiovascular anomalies, and other skeletal and connective tissue abnormalities. Ocular manifestations may include hypertelorism, downslanting palpebral fissures, proptosis, myopia, and ectopia lentis. We describe a 25-year-old male with the syndrome. Genetic analysis revealed a novel c.350G>A (p.Arg117His) de novo variant, which was predicted to be pathogenic by the CTGT laboratory. The patient presented with dysmorphic features, marfanoid habitus, severe joint contractures, mitral valve insufficiency, aortic root dilatation, and a history of seizures. His ocular manifestations included hypertelorism, downslanting palpebral fissures, bilateral ptosis, and high myopia. Ophthalmic manifestations are an integral component of the syndrome; however, they have not been well characterized in the literature. From a systematic review of previously published cases to date, we summarize the eye and ocular adnexa manifestations reported

    Wil in liberal arts programs: New approaches

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    In a service-led, knowledge-based economy, employers increasingly expect universities to deliver a workforce suited to this environment. This emphasis is evident in contemporary Australian higher education, which is shifting to an acquisition of vocational outcomes. However, vocational outcomes are not traditionally viewed as outcomes of liberal arts programs. Balancing new expectations with traditional perspectives generates a tension between assuring graduates employment outcomes and maintaining the integrity of the Bachelor of Arts (BA) as a liberal arts program. Getting it wrong can result in fragmented and unstable curricula. One of the many ways that Australian BA programs are grappling with this problem is through the provision of work-integrated learning (WIL) opportunities for liberal arts students. In professions-based programs such as engineering or dentistry, the shape and nature of these courses may be obvious. It is less so in the generalist BA. Australian BA programs offer students the opportunity to engage with WIL in a variety of ways. Evidence from national studies investigating the Australian BA between 2008 and 2016 highlight common features of practice such as the objectives, activities, and structure, and indicate that two approaches to providing WIL opportunities in the BA are evident. In order to meet the goals and aspirations of both economic and social purposes of higher education, liberal arts programs tend to adopt either a transactional or a transformational model. Each model has particular characteristics and approaches to practice that can inform the development of new programs and policies more globally
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