14 research outputs found

    Optimal signal timing signalized intersection by global optimization (OPT-I)

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    Accurate measurements of signal control parameters at signalized intersections are very important for designing and operating traffic control systems. In this work, a queuing system has been modelled as a result from the characterization of the vehicles behaviour approaching and passing of a signalized intersection. This intersection is part of a network of urban traffic and two problems are formulated, distinguished by the type of control used: pretimed, semi-actuated or fully-actuated. Subsequently global optimization and complementarity can be used to determine the parameters of the control signal. This formulation includes the green times and cycle lengths that minimize the total waiting time of vehicles at the intersection. At intersections regulated by actuated control, this methodology allows us to estimate the effective green time in actuated streams as well as the length of each cycle. It should be noted that the duration of departure of vehicles when signal is green or yellow is constant. The vehicles arrivals are random, following a Poisson probability distribution. The models in question were formulated as linear programs with linear complementarity constraints (LPLCC). In the present study, the Sequential Linear Complementarity Algorithm (SLCP) was also analysed to calculate the global minimum for the LPLCC. Furthermore, several scenarios of traffic intersections are created to demonstrate the method's efficiency, particularly to verify the accuracy of the solutions of the problems

    Impact of air barriers application in LCA and LCC of naturally ventilated dwellings in mild climate regions

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    "Available online 17 November 2022"Assessing singular elements that constitute the air barrier of a building envelope is quite unfeasible in Life Cycle Assessment (LCA). The study of these solutions through this particular scope is often overlooked. Two major aspects contribute to it: the complexity of the relationships between elements and the reduced embodied impact of these materials in the overall construction or retrofitting works. This work uses LCA and Life Cycle Costing (LCC) to study the viability of applying two envelope air barrier solutions in dwellings with excessive air change rates and equipped with different heating systems. The application of air barrier solutions resulted in average energy consumption savings in urban terrain, almost half of those in rural terrain during the heating season. Environmental performance and life cycle costs revealed mechanically (MECH) fastened air barriers to outperform fluid (FLUID) applied ones. The median annualized cost of adopting a FLUID solution was almost four times that of a MECH solution. Dwellings equipped with electric radiators ranked first in the shortest average Energy Payback Period (EPP) and the highest average Reference Service Life (RSL) savings. With the current analysis, the adoption of MECH solutions is recommended, independently of the heating system the dwelling is equipped with.This work was financially supported by: Base Funding - UIDB/04708/2020 and Programmatic Funding - UIDP/04708/2020 of the CONSTRUCT - Instituto de I&D em Estruturas e Construções - funded by national funds through the FCT/MCTES (PIDDAC). The author would like to acknowledge the support of FCT - Fundação para a Ciência e a Tecnologia, the funding of the Doctoral Grant PD/BD/135162/2017, through the Doctoral Programme EcoCoRe. This work is supported by the European Social Fund (ESF), through the North Portugal Regional Operational Programme (Norte 2020) [Funding Reference: NORTE-06-3559-FSE-000176]

    Artefacts induced on c-type haem proteins by electrode surfaces

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    J Biol Inorg Chem (2011) 16:209–215 DOI 10.1007/s00775-010-0717-zIn this work it is demonstrated that the characterization of c-type haem containing proteins by electrochemical techniques needs to be cautiously performed when using pyrolytic graphite electrodes. An altered form of the cytochromes, which has a redox potential 300 mV lower than that of the native state and displays peroxidatic activity, can be induced by interaction with the pyrolytic graphite electrode. Proper control experiments need to be performed, as altered conformations of the enzymes containing c-type haems can show activity towards the enzyme substrate. The work was focused on the study of the activation mechanism and catalytic activity of cytochrome c peroxidase from Paracoccus pantotrophus. The results could only be interpreted with the assignment of the observed non-turnover and catalytic signals to a non-native conformation state of the electron-transferring haem. The same phenomenon was detected for Met–His monohaem cytochromes (mitochondrial cytochrome c and Desulfovibrio vulgaris cytochrome c-553), as well as for the bis-His multihaem cytochrome c 3 from Desulfovibrio gigas, showing that this effect is independent of the axial coordination of the c-type haem protein. Thus, the interpretation of electrochemical signals of c-type (multi)haem proteins at pyrolytic graphite electrodes must be carefully performed, to avoid misassignment of the signals and incorrect interpretation of catalytic intermediates

    Infrared Thermography to Evaluate Thermal Comfort under Controlled Ambient Conditions

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    Infrared thermography (IRT) is often used to assess body temperature and can be useful as a diagnostic tool to detect human diseases. Despite this clear application in medicine, some studies can be found in the literature pointing to the use of IRT to measure body temperature as a parameter to evaluate thermal comfort inside buildings. However, there are still some issues that are understudied that this paper tried to address. For this purpose, an intensive experimental campaign was carried out, in which different combinations of temperature and relative humidity were implemented. Thermal images were taken of the face of a young adult, while the air temperature and relative humidity were assessed, as well as the body temperature, using traditional means. The results confirmed that different IR cameras and different ambient conditions (air temperature) impact the image resolution and definition. A linear correlation between the IRT results and the PMV was found for six subregions of the face. This correlation was higher in the forehead, cheekbones, and chin, and less interesting when measuring the temperature of the nose. However, if the overall temperature of the face is assessed, a good agreement between the PMV and the IRT results can still be found, indicating that the average facial temperature can be used as an indicator for the determination of thermal comfort. A prediction model for PMV based on IRT was proposed, with a root mean square error close to 0.70, when applied in a face temperature range between 28.9 °C and 34.4 °C

    Infrared Thermography to Evaluate Thermal Comfort under Controlled Ambient Conditions

    No full text
    Infrared thermography (IRT) is often used to assess body temperature and can be useful as a diagnostic tool to detect human diseases. Despite this clear application in medicine, some studies can be found in the literature pointing to the use of IRT to measure body temperature as a parameter to evaluate thermal comfort inside buildings. However, there are still some issues that are understudied that this paper tried to address. For this purpose, an intensive experimental campaign was carried out, in which different combinations of temperature and relative humidity were implemented. Thermal images were taken of the face of a young adult, while the air temperature and relative humidity were assessed, as well as the body temperature, using traditional means. The results confirmed that different IR cameras and different ambient conditions (air temperature) impact the image resolution and definition. A linear correlation between the IRT results and the PMV was found for six subregions of the face. This correlation was higher in the forehead, cheekbones, and chin, and less interesting when measuring the temperature of the nose. However, if the overall temperature of the face is assessed, a good agreement between the PMV and the IRT results can still be found, indicating that the average facial temperature can be used as an indicator for the determination of thermal comfort. A prediction model for PMV based on IRT was proposed, with a root mean square error close to 0.70, when applied in a face temperature range between 28.9 °C and 34.4 °C

    Oxocomplexes of U(vi) with 8-hydroxyquinoline-5-sulfonate in solution: structural studies and photophysical behaviour

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    Multinuclear (1H and 13C) NMR, and Raman spectroscopy, combined with DFT calculations, provide detailed information on the complexation between U(vi) oxoions and 8-hydroxyquinoline-5-sulfonate (8-HQS) in aqueous solution. Over the concentration region studied, U(vi) oxoions (uranyl ions) form one dominant complex with 8-HQS in water in the pH range 3-6, a mononuclear 1 : 2 (metal : ligand) complex, with the metal centre (UO22+) coordinated to two 8-HQS ligands, together with one or more water molecules. An additional minor 1 : 1 complex has also been detected for solutions with a 1 : 1 metal : ligand molar ratio. The geometry of the dominant complex is proposed based on the combination of the NMR and Raman results with DFT calculations. Further information on the electronic structure of the complex has been obtained from UV/visible absorption and luminescence spectra. The complex of U(vi) and 8-HQS is non-luminescent, in contrast to what has been observed with this ligand and many other metal ions. We suggest that this is due to the presence of low-lying ligand-to-metal charge transfer (LMCT) states below the emitting ligand-based and uranyl-based levels which quench their emission. These studies have fundamental importance and are also relevant in the context of environmental studies, and the water soluble ligand 8-HQS has been chosen for application in uranium remediation of aqueous environments
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