3D printing, Business, Chemicals, plastics and rubber industries, and Chemistry
Abstract
The use of 3D-printed tooling for thermoformed parts is an emerging development in additive manufacturing that is paying significant dividends in terms of reduced tooling cost and time for prototype [...]
The British Journal of Sociology. June, 2020, Vol. 71 Issue 3, p503, 17 p.
Subjects
Social sciences and Sociology and social work
Abstract
Keywords: curatorial interventions; public frictions; smart city; urban laboratory; urban prototyping Abstract The use of prototypes as testing instruments has become a common strategy in the innovation of services and products and increasingly in the implementation of 'smart' urban policies through living labs or pilots. As a technique for validating hypotheses about the future performance of products or policies, prototyping is based on the idea of generating original knowledge through the failures produced during the testing process. Through the study of an experimentation and prototyping project developed in Santiago de Chile called 'Shared Streets for a Low-Carbon District,' I analyse the technique of prototyping as a political device that can make visible (or invisible) certain entities and issues, determining what the experimental entities can do and say. I will show how the technique of prototyping defines modes of participation, what is visible and thinkable, what can be spoken and what is unspeakable. In this sense, I examine two ambivalent capacities of prototyping: as a mechanism of management and enrolment that seeks to prescribe normativities (problem-validating prototype) and as an event that can make frictions tangible, articulating matters of concern and ways to open up alternative scenarios (problem-making prototype). Byline: Martin Tironi
Background: Reconstruction intramedullary nail spanning the whole length of the femur has been the gold standard treatment for complete atypical diaphyseal fractures of the femur (ADF). However, in cases of incomplete ADF combined with severe bowing, this approach might have complications and lead to iatrogenic complete fracture. We report two cases of incomplete ADF with severe bowing using a precontoured plate (PCP) after rapid prototyping (RP) of the deformed femurs with three‐dimensional printing (3DP) technology. Case presentation: Two patients presented with gradually worsening thigh pain, especially during walking. The patients had been using bisphosphonates for 4 and 10 years, respectively. Radiography showed an incomplete fracture in the lateral cortex of the right femur shaft. The lateral bowing angles measured in the affected femurs were 15° and 14°, and the anterior bowing angles were 20° and 16°, respectively. In bone scans, both patients showed hot uptake in the right mid‐shaft of the femur. Preoperatively, the affected femur of the patient was reconstructed by 3DP RP using CT, and the plate was bent to the shape of the bone model. The ADF was fixed with a PCP using the minimally invasive plate osteosynthesis technique. Both patients were encouraged to start full weight‐bearing and return to their preinjury activity level in daily life immediately after surgery. At 2 years postoperatively, radiography showed healing of the fracture site without recurrence of thigh pain and implant‐related problems. Conclusion: Although intramedullary nailing is the standard surgical treatment for complete ADF, PCP using 3DP RP could be an effective treatment option for incomplete ADF with severely curved femur. [ABSTRACT FROM AUTHOR]
This article presents a novel sensor for detecting and measuring angular rotation and proximity, intended for rapid prototyping machines. The sensor is based on a complementary split-ring resonator (CSRR) driven by a conductor-backed coplanar waveguide (CBCPW). The sensor has a planar topology, which makes it simple and cost-effective to produce and accurate in measuring both physical quantities. The sensor has two components, a rotor and a stator: the first of these (the CSRR) can rotate around its axis and translate along the plane normal to the ground of the CBCPW. A detailed theoretical and numerical analysis, along with a circuit model, of the unique sensor design is presented. The proposed sensor exhibits linear response for measuring angular rotation and proximity in the range of 30°–60° and 0–200 μm, respectively. Another distinctive feature of the rotation and proximity sensor is the wide frequency band of applicability, which is an integral part of its novel design and is implemented through various dielectric material loadings on the CSRR. In the prototype of the proposed device, the stator (CBCPW) is fabricated on a 0.508-mm-thick RF-35 substrate, whereas the CSRR-based rotor is fabricated on TLY-5 and RF-35 substrates. The angular rotation, proximity, operating band selection, and sensitivity are measured using a vector network analyzer and are found to be good matches to the simulated and theoretical results. [ABSTRACT FROM AUTHOR]
