108 research outputs found

    Thermally induced bias errors for a fiber coil with practical quadrupole winding

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    This paper presents an advanced thermal modeling of a fiber optic gyroscope (FOG) coil. We extended the current models to practical quadrupole winding. Model covers homogenization/dehomogenization parameters of fiber coil. A simulation environment is created by the Finite Element Method (FEM). Simulation environment is validated by comparing the results with laboratory FOG experiments. © 2017 IEEE

    Modeling of thermal sensitivity of a fiber optic gyroscope coil with practical quadrupole winding

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    Thermally induced bias error is one of the main performance limits for the fiber optic gyroscopes (FOGs). We reviewed the thermal sensitivity of FOG in detail and created a simulation environment by the Finite Element Method (FEM). Thermal sensitivity analysis is based on Shupe and elastooptic effects. Elastooptical interactions are modeled by using the two different FEM simulations and homogenization-dehomogenization processes. FEM simulations are validated by comparing the results with a laboratory FOG setup. We report the changes in the error characteristics for practical quadruple winding patterns. © COPYRIGHT SPIE. Downloading of the abstract is permitted for personal use only

    Energy poverty in Portugal, Italy, and Norway: awareness, short-term driving forces, and barriers in the built environment

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    Portugal, Italy, and Norway differ by energy performance of buildings and gross domestic product (GDP). Portugal has significantly highest thermal discomfort with harsher winters. In 2021, 80% of Portuguese buildings had a low energy rating, with 75% of buildings without thermal insulation, highly contributing to the energy poverty (EP) of the country. In Italy, despite a generally mild climate, the building stock has low thermal performance. The most affected areas are the suburban and peri-urban ones, with an EP rate in southern regions between 13% and 20% compared to 8.8% at national level. Moreover, 65% of buildings were constructed before the first law on energy saving criteria and a 25% of it has never undergone any work of maintenance or improvement. Norway, despite the limited studies performs well respect to other European Economic Area and European Union countries, in investing and using indicators to enhance and monitor the green energies’ use. Because of energy price growth, seasonal price fluctuations, and different energy tariffs, energy inequality is increasing. EP risk is underestimated, masked by Norway's high GDP and regional price disparity. Energy inequality is increasing due to energy price growth, seasonal price fluctuations, and energy prices’ geographical inequality. The barriers in reducing EP are the underestimation of risk masked by the high GDP, and the need of homogenized prices in Norway. This study provides an overview to discuss EP awareness and it assesses the drivers and barriers that influence building's energy efficiency renovatio

    A dataset of criteria on the use of thermal insulation solutions in building facades located in Norway, Portugal and Italy

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    The building sector is responsible for a significant percentage of the energy consumption in Europe. The level of thermal insulation of the building envelope leads to decrease energy consumption, thus contributing towards a sustainable and efficient built environment. As a result, the choice of the most suitable thermal insulation solution to be applied both in new construction and in retrofitting of building facades is fundamental for a satisfactory thermal performance of the building. Nevertheless, the thermal insulation solution should not be chosen considering only the thermal performance, but rather based on a set of performance parameters (i.e., water resistance, fire performance, impact on the environment and human health, among others) and climate-related requirements. This data article includes a dataset on criteria adopted in three European countries (namely Norway, Portugal, and Italy) considering a PESTE analysis (i.e., criteria related to Political, Economic, Social, Technological, and Environmental questions). The main objective was to evaluate the knowledge and perception of people living and/or working in these countries about the use and the performance of thermal insulation solutions in building facades. To this aim a questionnaire was developed within the scope of the EEA Granted EFFICACY research project (November 2022 – February 2023), whose overall objective is to create a database that serves as a reference for the choice of thermal insulation solutions to be applied in building facades for thermal and energy performances optimization. This database contributes to systemize criteria and can be extended by other researchers or professionals in the area, as well as in other countries

    Modes of Foreign Entry under Asymmetric Information about Potential Technology Spillovers

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    This paper studies the effect of technology spillovers on the entry decision of a multinational enterprise into a foreign market. Two alternative entry modes for a foreign direct investment are considered: Greenfield investment versus acquisition. We find that with quantity competition a spillover makes acquisitions less attractive, while with price competition acquisitions become more attractive. Asymmetric information about potential spillovers always reduces the number of acquisitions independently of whether the host country or the entrant has private information. Interestingly, we find that asymmetric information always hurts the entrant, while it sometimes is in favor of the host country

    Treatment of hallux valgus by modified McBride procedure: a 6-year follow-up

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    PubMed ID: 20505975Background Surgical decision-making was reevaluated by comparison with an algorithm designed to analyze treatment of hallux valgus deformities. Materials and methods A modified McBride procedure was performed on 52 feet of 35 patients with hallux valgusdeformity. From this series, 36 feet of 21 patients were evaluated preoperatively, early postoperatively, and late postoperatively by means of subjective evaluation and clinical and radiological findings. Results The hallux valgus angle preoperatively, early postoperatively, and late postoperatively was 32.7 ± 8.5°, 10.1 ± 6.9°, and 20.6 ± 9.5°, respectively. Hallux valgus recurrence of 72.2% was observed. Subjective results were better and the patients rated their satisfaction with the procedure as excellent or high in 23 cases (63.9%) and moderate, low, or unsatisfactory in 13 cases (36.1%). Conclusions This level of patient satisfaction demonstrates that the McBride procedure is an efficient approach for eliminating pain due to hallux valgus deformity. © The Author(s) 2010

    Treatment of hallux valgus by modified McBride procedure: a 6-year follow-up

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    PubMed ID: 20505975Background Surgical decision-making was reevaluated by comparison with an algorithm designed to analyze treatment of hallux valgus deformities. Materials and methods A modified McBride procedure was performed on 52 feet of 35 patients with hallux valgusdeformity. From this series, 36 feet of 21 patients were evaluated preoperatively, early postoperatively, and late postoperatively by means of subjective evaluation and clinical and radiological findings. Results The hallux valgus angle preoperatively, early postoperatively, and late postoperatively was 32.7 ± 8.5°, 10.1 ± 6.9°, and 20.6 ± 9.5°, respectively. Hallux valgus recurrence of 72.2% was observed. Subjective results were better and the patients rated their satisfaction with the procedure as excellent or high in 23 cases (63.9%) and moderate, low, or unsatisfactory in 13 cases (36.1%). Conclusions This level of patient satisfaction demonstrates that the McBride procedure is an efficient approach for eliminating pain due to hallux valgus deformity. © The Author(s) 2010

    Heavy and light roles: myosin in the morphogenesis of the heart

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    Myosin is an essential component of cardiac muscle, from the onset of cardiogenesis through to the adult heart. Although traditionally known for its role in energy transduction and force development, recent studies suggest that both myosin heavy-chain and myosin lightchain proteins are required for a correctly formed heart. Myosins are structural proteins that are not only expressed from early stages of heart development, but when mutated in humans they may give rise to congenital heart defects. This review will discuss the roles of myosin, specifically with regards to the developing heart. The expression of each myosin protein will be described, and the effects that altering expression has on the heart in embryogenesis in different animal models will be discussed. The human molecular genetics of the myosins will also be reviewed

    Computation of metallic nanofluid natural convection in a two-dimensional solar enclosure with radiative heat transfer, aspect ratio and volume fraction effects

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    As a model of nanofluid direct absorber solar collectors (nano-DASCs), the present article describes recent numerical simulations of steady-state nanofluid natural convection in a two-dimensional enclosure. Incompressible laminar Newtonian viscous flow is considered with radiative heat transfer. The ANSYS FLUENT finite volume code (version 19.1) is employed. The enclosure has two adiabatic walls, one hot (solar receiving) and one colder wall. The Tiwari-Das volume fraction nanofluid model is used and three different nanoparticles are studied (Copper (Cu), Silver (Ag) and Titanium Oxide (TiO2)) with water as the base fluid. The solar radiative heat transfer is simulated with the P1 flux and Rosseland diffusion models. The influence of geometrical aspect ratio and solid volume fraction for nanofluids is also studied and a wider range is considered than in other studies. Mesh-independence tests are conducted. Validation with published studies from the literature is included for the copperwater nanofluid case. The P1 model is shown to more accurately predict the actual influence of solar radiative flux on thermal fluid behaviour compared with Rosseland radiative model. With increasing Rayleigh number (natural convection i.e. buoyancy effect), significant modification in the thermal flow characteristics is induced with emergence of a dual structure to the circulation. With increasing aspect ratio (wider base relative to height of the solar collector geometry) there is a greater thermal convection pattern around the whole geometry, higher temperatures and the elimination of the cold upper zone associated with lower aspect ratio. Titanium Oxide nano-particles achieve slightly higher Nusselt number at the hot wall compared with Silver nano-particles. Thermal performance can be optimized with careful selection of aspect ratio and nano-particles and this is very beneficial to solar collector designers
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