Flat plate solar collector efficiency. Theoretical aspects of the quadratic form |
Author : drd. ing. Alexandru Draghici, prof. dr. ing. Florin Iordache |
Abstract | Full Text |
Abstract :This paper presents the results of a numerical simulation concerning the solar radiation collecting and heat transfer processes associated with a flat plate solar collector. The main studied parameters are the overall heat transfer coefficient of the collector (kC) and the collecting efficiency (niuC). During the simulation, convective and radiative heat transfer processes between the absorbent plate and glazing have been considered. The obtained results are graphically presented and commented. |
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Aspects regarding the corrosion prediction of earth electrodes in the soil of the municipality of Timisoara Part III. The mathematical prediction of corrosion |
Author : Stefan PAVEL, Ioan-Bogdan PASCU, Bogdan-Ovidiu TARANU, Oana-Alexandra GRAD, Romeo NEGREA |
Abstract | Full Text |
Abstract :Corrosion prediction of galvanized steel ground electrodes in the soil of Timisoara |
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Innovation of pneumatic waste in building sound insulation systems against internal and external noise |
Author : Bounoua TAB, Ahmed TAFRAOUI, Naima SEGHOUANI |
Abstract | Full Text |
Abstract :After the experiment of the same material in thermal insulation, the present work is a new investigation to answer the problem of acoustic comfort of the constructions while clearing the environment of the pneumatic waste which by their long life occupy large spaces and by their incineration emit polluting gases. Numerous tests have been carried out on reduced or real models representing either the floors or partition walls that are the main conductors of sound in a building. In comparison with the expensive materials currently used in acoustic insulation, the proposed innovation has shown unexpected technical sound insulation performances accompanied by a great economic interest. |
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Case study regarding the energy efficiency of green buildings envelope |
Author : Georgiana Corsiuc, Carmen Marza |
Abstract | Full Text |
Abstract :Green buildings must use materials with a positive impact on the human being and environment while ensuring a high degree of thermal insulation. The structure of the exterior wall proposed by the authors was designed to meet as many requirements as possible: to have good insulating properties and a proper behavior to the diffusion of vapors, to comply with the requirements imposed by regulations regarding the thermal stability of the construction elements, to use environmentally friendly materials and also to have a light weight so that it can be prefabricated or used in modular constructions that require transport and manipulation. |
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Analysis and estimation of parameters influencing hot gas layer temperatures in a fire compartment as a function of the type of the ventilation system |
Author : Alexandra TEODOR, Alexandru-Florin CHIOJDOIU, Octavian LALU, Ion ANGHEL, Aurel TROFIN, Ionel Alin MOCIOI,Liviu-Valentin BALANESCU |
Abstract | Full Text |
Abstract :In this study, some empirical methods were used to estimate the temperatures of the hot gas layer in a fire compartment with standardised dimensions. A number of assumptions and limitations were imposed on the methods used, on the basis of which two fire scenarios were analysed, namely: the fire compartment, whose inner surfaces are lined, successively, with chipboard, gypsum board, expanded polystyrene and concrete is natural ventilated, respectively mechanically ventilated. It was also considered that the value of the heat release rate (HRR) is constant, with values of 250 kW, 500 kW and 1000 kW. By using the Fire Dynamics Tools (FDTs) developed by the US Nuclear Regulatory Commission [11], diagrams of the temperature of the hot gas layer were obtained and a comparative analysis of the results was performed. Thus, it was found that the temperature values of the hot gas layer released in a fire compartment are influenced by a number of parameters, such as: the thermal properties of the interior finishes, the heat release rate, the geometry of the fire compartment, respectively the ventilation system that was used. On the premises of Fire Safety Engineering Faculty, one such a fire compartment was built. In the fire compartment. This fire compartment will be used for, experimental tests that are to be conducted in order to validate the empirical results initially estimated with FDT6. |
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Hydromechanical coupling in the soil-structure interaction |
Author : Belbekri M., Draoui B., Berga A. |
Abstract | Full Text |
Abstract :Historically,in civilengineering construction,the structural design takes account the gravity, overloadand waterpressure as fundamental forces. Becomes later the consideration of the dynamics effects as the machine vibration and the earthquake,the fire resistance...etc. After all,the survey of projects like building,road,pavement -asexample- show that there is always appearance of various anomalies and damages that are evolutionary in time. Often,they can be due to the watercycle.The paper handles the hydromechanical couplingcase,shows how conducting the analysis and proof the feasibility of the structural design in these conditions.The results are obtained in the frame of the finite element analysis and they open the horizon for more improvements. |
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Climatic impact of atmospheric particles; Case study for Bucharest municipality |
Author : Florinela Ardelean |
Abstract | Full Text |
Abstract :Emissions resulted from road transport participate directly and indirectly to climate changes felt at local, regional and planetary levels. Solid and liquid aerosols influence the urban troposphere from a physical and chemical perspective, modify the radiative balance recorded at the earth’s surface and atmosphere, and affect the biosphere and implicitly human health. Using a database created from hourly average values of PM10 particles concentrations, corresponding to 2018 and 2019, air quality in Bucharest will be analyzed in strong connection with specific indices, in the cold as well as hot periods. Certain time intervals within the day, in which pollution potential increases significantly, will be identified. The data obtained can be used in elaborating an atmosphere protection strategy with landscaping measures |
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Data security in fixed power installations of the railway electric traction system |
Author : Cristina Gabriela Saracin |
Abstract | Full Text |
Abstract :This paper presents a viable solution for data security within the fixed power installations of the railway electric traction system. Transmission of process information to control, surveillance and data acquisition structures (SCADA) is done through the private local network and the public network (cloud servers). Under these conditions, unauthorized persons access to the railway network becomes possible. With this in mind, the paper focuses on the management of railway power distributors and their security methods. For each equipment, its level of accessibility resulting from the degree of vulnerability is identified. Therefore, data security measures must be taken to prevent potential negative consequences for the computer system. Cyber attacks on the computer network within the railway dispatchers can take place internally (SCADA) and externally (protocols and data transmissions). Information security, in the context of real-time data traffic management within the rail energy dispatcher, leads to an increase in the level of protection of national and European critical infrastructures. |
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Dynamic thermal behavior of an active hot water preparation system using solar energy |
Author : drd. ing. Alexandru Draghici, prof. dr. ing. Florin Iordache |
Abstract | Full Text |
Abstract :The main objective of this paper is to model and simulate the dynamic thermal behavior of an unconventional system that uses solar energy for supplying a domestic hot water consumer.The system is composed of a water tank and a solar loop, containing the solar energy collecting surface and a heat exchanger sunk in the tank. Moreover, the system includes a three way valve and a pipe which bypasses the water tank, with the purpose of controlling the temperature of the delivered hot water. Finally, the constructional optimization of the unconventional system is targeted. |
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Comparative study for the supply of a block of flats with thermal agent |
Author : Constantin CILIBIU |
Abstract | Full Text |
Abstract :The paper presents a case study for the supply of thermal agent to a housing block that is currently powered by a block thermal power station, serving the entire building. The analysis is done for two distinct technical solutions, the first option being the rehabilitation and modernization of the existing thermal power station, and the second solution is with the installation of individual apartment plants. |
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Numerical determination of the temperature two-dimensional field in a plane region in stationary thermal solution resolved in Excel Microsoft |
Author : Sef lucr. Dr. ing. Gelu-Adrian CHISALITA |
Abstract | Full Text |
Abstract :The paper presents the construction and use of a new software tool for numerical analysis of the two-dimensional temperature distribution in a flat region of rectangular shape of a body with constant thermal conductivity and no generation, when the temperatures on the bounding surfaces of the body are known. The finite difference method (FDM) is used to solve the system of linear equations by properly calling the Solver tool from the Microsoft Excel® software application. |
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Mechanical properties of high-performance concrete made incorporating dune sand as fine aggregate. |
Author : Fatima Zahra Rennani, Abdelkadir Makani, Noureddine Agha, Ahmed Tafraoui, Farid Benmerioul, Said Zaoiai |
Abstract | Full Text |
Abstract :The main objective of this research is to contribute to an experimental study of the behavior of high-performance concrete (HPC) based on dune sand of Taghit (Bechar-Algeria). T |
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