Revista Jurídica Digital UANDES
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EFFECT OF LOCAL STRAIN AND GND DENSITY ON CRACK INITIATION IN ALLOY 600.
No full textIn this work, strain and geometric necessary dislocation (GNDs) have been measured around various grain boundaries after subjected to a 4-point bend test in simulated PWR primary water conditions, with the aim of clarifying which local conditions trigger SCC initiation. Three different regions are compared: in a cracked grain boundary, the cracked and the uncracked portions are compared to a similar grain boundary in the as-received material. l. To study this, “on-axis” Transmission Kikuchi Diffraction (TKD) with a step size of 1 nm followed by GND analysis and cross-correlation based strain mapping, was performed. Results together with a discussion on the limitations of the approach will be presented
REDUCED-ORDER MODELLING OF MINERAL DUST DEPOSITION IN TURBOSHAFT ENGINE HOT SECTIONS
No full textOperating in brownout conditions is a hazardous yet often unavoidable consequence of using rotorcraft in dry, arid environments. Significant quantities of the lofted dust cloud can be ingested into the helicopters engines where they cause damage in both the main gas path and secondary air systems. Molten particle accumulation on nozzle guide vanes has the potential to restrict the core mass flow and cause the engine to surge. Predicting the conditions under which this happens is complicated by the many separation and sorting processes that occur in the preceding sections of the engine. This contribution demonstrates a reducedorder, probabilistic methodology that can be used in conjunction with in-field particle sampling to predict the extent of nozzle guide vane damage and assess the risk of engine surge when operating in a particular environment. The processing of the raw ingested dust in the compressor and particle separator system is shown to be significant in accurately predicting the extent of damage and suggests that taking particle samples from the bulk dust cloud is likely to provide under-estimations of the actual damage seen in the engine. <br/
Understanding collaborative working in a facilitated interdisciplinary environment
No full textPurpose: This paper reports on a new form of project insurance in UK construction designed to improve collaborative working among project participants. It aims to examine the interprofessional collaborative endeavour under the new insurance arrangements, drawing on a structuration model of interdisciplinary collaboration developed in the field of healthcare studies. Design/Methodology/Approach: The research employed a longitudinal, action research approach with participant observation. A novel element included a project facilitator as part of the action research team. Qualitative and quantitative data were collected using semi-structured interviews with close scrutiny of the documented project record. Findings: Project structure emerges as a more important element in the collaboration process than is typically recognised in practice-based studies; the analysis revealing the interplay of structure, the socialising processes of participants and how facilitation helps develop interdependence among project participants. The analysis provides a basis for understanding collaboration on the trial project. Research limitations/implications: The project provides a unique context for the examination of collaboration under the new project insurance arrangements. The results have implications for the study of collaboration in highlighting the important relationship between project structure, collaboration and facilitation. Practical implications: Understanding how interdependency is developed through structure, the socialising processes of collaborators, and facilitation has important implications for those concerned with designing project arrangements and managing collaborative processes. Originality/value: The paper reports on the first full trial of new project insurance arrangements in the UK. It highlights the significance of project structure, and the interplay between collaborators’ emerging practices and facilitation.<br/
Biomechanical effect of threading on proximal humeral locking screws: a finite element study
No full textAre optical imaging small satellites in the EO market a disruptive technology?
No full textAfter decades of traditional space businesses, the space paradigm is changing. Conventional projects based on customization, large budgets, extended time framework, and requesting huge amounts of resources are no longer feasible in the new space market. New approaches to more efficient missions in terms of costs, design and manufacturing processes are fostered. For instance, placing big constellations of micro and nano-satellites in Low and Very Low Earth Orbits (LEO and VLEO) enablethe space community to obtain a huge amount of data in near real-time with an unprecedented temporal resolution (Denis et al. 2017) . Beyond technology innovations, there are other drivers that promote the innovation in the space sector like the increasing demand of Earth Observation (EO) data by the commercial sector. Euroconsult report (2018) stated that the EO industry is the second market in terms of operative satellites (661 units), being micro and nano-satellites the higher share of them (61%). Technological and market drivers encourage the emergence of new start-ups in the space environment like Skybox, OneWeb, Telesat, Planet, OpenCosmos, among others, with novel business models that change the accessibility, affordability, ownership and commercialization of space products and services. This paper shows some results of the H2020 project DISCOVERER, and focuses on understanding how micro and nano-satellites have been disrupting the EO market in front of traditional platforms
Remarkable improvement in corrosion properties of Al substrates by means of alumina-zirconia nanostructured coating through PEO method
No full textCompact alumina-zirconia nano composites with corrosion protection potential were coated on 7075 Al alloy through the Plasma Electrolytic Oxidation (PEO) method in DC galvanostatic mode. The layers were coated at constant current density of 20 A/dm2 and 100-350 s growth time in an alkaline K2ZrF6 containing electrolyte. The characteristics of the coatings were investigated as a function of PEO processing time. Electrochemical properties of the layers were studied by conducting potentiodynamic polarization experiments in 3.5% NaCl solution. The results showed that under the present PEO experimental conditions, alumina-zirconia nanostructured coatings can be produced with 10-30 m thickness and 0.4-2.35 m roughness depending on the processing time. Phase analysis showed that the nanostructured coatings contained alumina and zirconia high temperature phases (tetragonal zirconia and a-alumina). Processing for 300 s was found to produce the most compact layer with low surface porosity (0.69%) and 26 m thickness. This particular PEO treatment was found to reduce the corrosion rate by 2.5 orders of magnitude compared to the uncoated substrate. This significant improvement in corrosion resistance is attributed to the barrier effect of the dense layer and the presence of tetragonal zirconia
The Nearby Evolved Stars Survey:I. JCMT/SCUBA-2 Sub-millimetre detection of the detached shell of U Antliae
No full textWe present the highest resolution single-dish submillimetre observations of the detached shell source U Antliae to date. The observations were obtained at 450 µm and 850 µm with SCUBA-2 instrument on the James Clerk Maxwell Telescope as part of the Nearby Evolved Stars Survey. The emission at 850 µm peaks at 4000 with hints of a second peak seen at ∼ 2000. The emission can be traced out to a radius of 5600 at a 3σ level. The outer peak observed at 850 µm aligns well with the peak observed at Herschel/PACS wavelengths. With the help of spectral energy distribution fitting and radiative transfer calculations of multiple-shell models for the circumstellar envelope, we explore the various shell structures and the variation of grain sizes along the in the circumstellar envelope. We determine a total shell dust mass of (2.0±0.3)×10−5 M and established that the thermal pulse which gave rise to the detached shell occurred 3500 ± 500 years ago
A Bi-directional Multiple Timescales LSTM Model for Grounding of Actions and Verbs
No full textIn this paper we present a neural architecture to learn a bi-directional mapping between actions and language. We implement a Multiple Timescale Long Short-Term Memory (MT-LSTM) network comprised of 7 layers with different timescale factors, to connect actions to language without explicitly learning an intermediate representation. Instead, the model self-organizes such representations at the level of a slow-varying latent layer, linking action branch and language branch at the center. We train the model in a bi-directional way, learning how to produce a sentence from a certain action sequence input and, simultaneously, how to generate an action sequence given a sentence as input. Furthermore we show this model preserves some of the generalization behaviour of Multiple Timescale Recurrent Neural Networks (MTRNN) in generating sentences and actions that were not explicitly trained. We compare this model with a number of different baseline models, confirming the importance of both the bi-directional training and the multiple timescales architecture. Finally, the network was evaluated on motor actions performed by an iCub robot and their corresponding letter-based description. The results of these experiments are presented at the end of the paper
Evaluating the Acceptability of Assistive Robots for Early Detection of Mild Cognitive Impairment
No full textThe employment of Social Assistive Robots (SARs) for monitoring elderly users represents a valuable gateway for at-home assistance. Their deployment in the house of the users can provide effective opportunities for early detection of Mild Cognitive Impairment (MCI), a condition of increasing impact in our aging society, by means of digitalized cognitive tests. In this work, we present a system where a specific set of cognitive tests is selected, digitalized, and integrated with a robotic assistant, whose task is the guidance and supervision of the users during the completion of such tests. The system is then evaluated by means of an experimental study involving potential future users, in order to assess its acceptability and identify key directions for technical improvements