Comportamento experimental de diferentes tipos de conectores metálicos

A realização de estruturas mistas de aço e betão requer o funcionamento conjunto destes dois materiais. A ligação entre eles é conseguida com a utilização de conectores metálicos. Neste âmbito, tem sido realizada uma considerável quantidade de estudos que abordam o comportamento de diversos tipos de conectores metálicos. O desejo de obter um comportamento óptimo com custos mínimos motivou o desenvolvimento de várias soluções. Neste artigo, procura-se descrever o comportamento de diferentes tipos de conectores observado em ensaios experimentais realizados na Universidade do Minho (UM) ou em estreita colaboração da UM com outras entidades. Apresentam-se as vantagens e as desvantagens associadas a cada tipologia de conexão analisada. Para além dos usuais conectores tipo perno, discutem-se os resultados obtidos com conectores do tipo T, tipo Perfobond, tipo Crestbond e ligação por aderência

The impacts of EU cohesion policy on sustainable tourism: The case of POSEUR in Algarve

Sustainable tourism is a main priority of European Union policies, with the aim of mitigating the potential harmful consequences of this sector on a given territory. The main research goal of this article is to better understand the impact of the public investments financed via EU Cohesion Policy in the tourism sector in the Portuguese Algarve NUT2. This paper focuses on the Portuguese Operational Programme for Sustainability and Efficient Use of Resources (POSEUR 20142020), which was an operational programme of a Portuguese framework to implement EU Cohesion Policy funds in Portugal between 2014 and 2020, and was specifically focused on supporting sustainable development processes. The sustainability performance of POSEUR in the Algarve was evaluated in five different dimensions of analysis: (1) low-emissions economy, (2) adaptation to climate change, (3) risk prevention and management, (4) environmental protection, and (5) resource efficiency. The results showed that POSEUR had a low impact in almost all dimensions in the Algarve, apart from the adaptation to climate change dimension, which exhibits a high impact score, mostly due to the support given for carrying out the Plans for Adaptation to Climate Change (PAAC).info:eu-repo/semantics/publishedVersio

Assessing impacts of environmental sustainability public policies in the Lisbon Metropolitan Area: Using the Impact-WEB-GIS platform

Urban environmental sustainability is a growing concern within the United Nations and European Union’s ongoing policy agendas to fight climate change. This paper contributes to this debate by presenting the main impacts of the Operational Programme for Sustainability and Use of Resources (POSEUR 2014– 2020) in the Lisbon Metropolitan Area (NUTS II). The analysis was supported by the use of the Impact-WEB_GIS platform, specially developed for the purpose of this study, complemented by a territorial impact assessment methodology. In addition to the production of general impact scores, five analytic dimensions were further analysed, supported by state of the art: i) low-emissions economy, ii) adaptation to climate change, iii) risk prevention and management, iv) environmental protection and v) resource efficiency. At a strategic level, the research created awareness of the need to adjust regional policy to the region’s characteristics on environmental sustainability matters.info:eu-repo/semantics/publishedVersio

Polarization squeezing of light by single passage through an atomic vapor

We have studied relative-intensity fluctuations for a variable set of orthogonal elliptic polarization components of a linearly polarized laser beam traversing a resonant $^{87}$Rb vapor cell. Significant polarization squeezing at the threshold level (-3dB) required for the implementation of several continuous variables quantum protocols was observed. The extreme simplicity of the setup, based on standard polarization components, makes it particularly convenient for quantum information applications.Comment: Revised version. Minor changes. four pages, three figure

Difference between the default telecoil (T-Coil) and programmed microphone frequency response in behind-the-ear (BTE) hearing aids

BACKGROUND: A telecoil (t-coil) is essential for hearing aid users when listening on the telephone because using the hearing aid microphone when communicating on the telephone can cause feedback due to telephone handset proximity to the hearing aid microphone. Clinicians may overlook the role of the t-coil due to a primary concern of matching the microphone frequency response to a valid prescriptive target. Little has been published to support the idea that the t-coil frequency response should match the microphone frequency response to provide “seamless” and perhaps optimal performance on the telephone. If the clinical goal were to match both frequency responses, it would be useful to know the relative differences, if any, which currently exist between these two transducers. PURPOSE: The primary purpose of this study was to determine if statistically significant differences were present between the mean output (in dB SPL) of the programmed microphone program and the hearing aid manufacturer’s default t-coil program as a function of discrete test frequencies. In addition, pilot data are presented on the feasibility of measuring the microphone and t-coil frequency response with real-ear measures using a digital speech-weighted noise. RESEARCH DESIGN: A repeated-measures design was utilized for a 2-cc coupler measurement condition. Independent variables were the transducer (microphone; t-coil), and eleven discrete test frequencies (fifteen discrete frequencies in the real-ear pilot condition). STUDY SAMPLE: The study sample was comprised of behind-the-ear (BTE) hearing aids from one manufacturer. Fifty-two hearing aids were measured in a coupler condition, 39 of which were measured in the real-ear pilot condition. Hearing aids were previously programmed and verified using real-ear measures to the NAL-NL1 prescriptive target by a licensed audiologist. DATA COLLECTION AND ANALYSIS: Hearing aid output was measured with a Fonix 7000 hearing aid analyzer (Frye Electronics, Inc.) in a HA-2 2-cc coupler condition using a pure-tone sweep at an input level of 60 dB SPL with the hearing aid in the microphone program and 31.6 mA/M in the t-coil program. A digital speech weighted noise input signal presented at additional input levels was used in the real-ear pilot condition. A mixed model repeated-measures Analysis of Variance (ANOVA) and the Tukey Honestly Significant Difference (HSD) post-hoc test were utilized to determine if significant differences were present in performance across treatment levels. RESULTS: There was no significant difference between mean overall t-coil and microphone output averaged across 11 discrete frequencies (F(1,102)=0, p<0.98). A mixed-model repeated measures ANOVA revealed a significant transducer by frequency interaction (F(10,102)=13.0, p<0.0001). Significant differences were present at 200 and 400 Hz where the mean t-coil output was less than the mean microphone output, and at 4000, 5000, and 6300 Hz where the mean t-coil output was greater than the mean microphone output. CONCLUSIONS: The mean t-coil output was significantly lower than the mean microphone output at 400 Hz, a frequency that lies within the typical telephone bandwidth of 300–3300 Hz. This difference may partially help to explain why some patients often complain the t-coil fails to provide sufficient loudness for telephone communication

Fábrica do Paleão: structural assessment of iron in Portugal’s industrial heritage

Fábrica do Paleão was erected as a flagship textile factory in Portugal between 1888 and 1891. The factory was constructed with a saw-tooth roof supported by iron trusses allowing light open spaces to accommodate heavy machinery and promote industrial activity. With an aim of preserving this exemplary representative of industrial heritage in Portugal, the work seeks to establish the buildings’ historical significance and assess their structural adequacy for present and future use. After performing a global historical survey and visual inspection, the study focused on the main industrial spaces. An in depth visual inspection provided key geometric and material parameters as well as a damage assessment. Damage mapping revealed the effects of moisture throughout the structure which is caused by the lack of maintenance in recent years. To assess the impact of the damages and obtain key parameters for a further structural and safety analysis, in situ tests were performed on the cast iron columns. Columns were tested for hardness and comparison to known values indicate that they align with ordinary to high strength cast iron. A representative single frame was modelled for each of the two main rooms and a safety analysis was performed to assess the structure´s safety.info:eu-repo/semantics/publishedVersio

Nighttime air quality under desert conditions

Nighttime concentrations of the gas phase nitrate radical (NO3) were successfully measured during a four week field campaign in an arid urban location, Reno Nevada, using long-path Differential Optical Absorbance Spectrometry (DOAS). While typical concentrations of NO3 ranged from 5 to 20ppt, elevated concentrations were observed during a wildfire event. Horizontal mixing in the free troposphere was considerable because the sampling site was above the stable nocturnal boundary layer every night and this justified a box modeling approach. Process analysis of box model simulations showed NO3 accounted for approximately half of the loss of internal olefins, 60% of the isoprene loss, and 85% of the α-pinene loss during the nighttime hours during a typical night of the field study. The NO3+aldehyde reactions were not as important as anticipated. On a polluted night impacted by wildfires upwind of the sampling location, NO3 reactions were more important. Model simulations overpredicted NO2 concentrations for both case studies and inorganic chemistry was the biggest influence on NO3 concentrations and on nitric acid formation. The overprediction may be due to additional NO2 loss processes that were not included in the box model, as deposition and N2O5 uptake had no significant effect on NO2 levels

Análise experimental e numérica da conexão aço-betão leve realizada com pernos de cabeça

O presente trabalho procura abordar a modelação numérica da conexão entre o perfil metálico e a laje de betão, quando se utilizam conectores do tipo perno e betão leve. Utilizam se elementos finitos de volume para definir todos os elementos presentes na ligação, recorrendo ao software ATENA 3D. A partir dos modelos desenvolvidos procura-se avaliar quais os parâmetros relevantes para o comportamento da conexão aço betão leve. Recorre-se a resultados de ensaios de tipo push out anteriormente realizados na Universidade do Minho para validar os modelos numéricos desenvolvidos