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.

Corrosion prediction of galvanized steel ground electrodes in the soil of Timisoara

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.

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.

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.

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.

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

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.

The paper shows alternative refrigerant mixtures for R134a that can be used in heat pump air-water systems with ecological alternatives R1234yf, R452A and R513A. In the article it is shown the calculation of COP with Chemours Refrigerant Expert software for single stage heat pump cycle. As a result of the new legislative strategy at international level regarding the refrigerants, in the following years must be find ecological alternatives in terms of global warming potential (GWP) in according with Fgas Regulation

In the light of the increasing exploitation of natural resources, a rigorous approach and an effective identification of practical solutions needed to ensure the conservation of the environment is required, given the crucial importance of this issue. This scientific work explores an innovative method of treatment and improvement of landfill gas produced from municipal and similar wastes, for a carefully selected and thoroughly studied landfill, in order to obtain a sustainable alternative fuel that can be used in natural gas installations.The method analyzed in this study is called high-pressure water scrubbing, which allow the production of biomethane. Additionally, using the mathematical model LandGEM, the energy potential and gas generation rate was determined, for a selected landfill located in Alba Iulia, Romania country. This article also provides a review of technology that uses the high-pressure water scrubber for the integration of improved landfill gas into the mobile cylinder. Through this investigation, the landfill in Alba Iulia, Alba administrative territorial unit, Romania, can be considered as an energetic resourse who can be used through a sustainable potential solution for protecting current natural resources

In modernizing energy systems, European countries are focusing on a smart energy system, and one of the goals of which is the rational use of energy resources and the reduction of negative environmental impact. The concept of the low temperature district heating in the smart energy system is one of opportunities to decrease loses and waste of energy and to implement a systemic approach to the energy use. A roll-out could begin selectively, based on experimental project activities in the near future, new construction will be used to develop the business infrastructure necessary for later, more widespread deployment. The aim of the research is to summarize challenges and benefits in the implementing of the low temperature district heating concept in the smart energy system. The object of the research: challenges and benefits in the implementing of the low temperature district heating concept. The objectives: to systemise the smart energy approach in sustainable future; to analyse the concept of the low temperature district heating in a smart energy system; to characterise risks and opportunities of the low temperature district heating concept. There were used these scientific methods: induction, systemic analysis, comparative analysis and synthesis of partial scientific knowledge. Analysis of various scientific articles and studies shows energy conservation, increased use of renewable energies, smart grids to promote renewable energy utilization, cleaner technologies, multigeneration, and efficient storage of energy carriers are necessary conditions for the transition to smart energy systems for a sustainable future. The low temperature district heating concept is associated with some forms of risk, but the dissemination of experience and on modern digital technologies based management can help to achieve ecological benefits although reduced CO2 emissions, minimize heat loses and waste of energy, to reduce costs of energy production and to improve the image of heating companies

In an existing office building, integrating air-to-water heat pumps into a district heating system can bring multiple benefits in terms of energy efficiency and thermal comfort. The article deals with the implementation solution for the efficiency of district heating systems, exemplified by a case study related to an existing office building. The study was carried out following the multiple breakdowns that occurred in the thermal energy distribution system from the district heating company, as well as the interruption of thermal energy for long periods of time

This study investigates the airborne transmission risk of infectious diseases in a classroom setting, aiming to develop a comprehensive risk measurement model. The research employs a combination of computational fluid dynamics simulations, viral load measurements, and epidemiological data to analyze airflow patterns, ventilation efficiency, and viral dispersion in classrooms. Real-time monitoring of air quality, temperature, and humidity is integrated to establish a risk assessment framework. The findings reveal the significance of proper ventilation and strategic classroom layout in mitigating airborne disease transmission. This research offers practical insights for educational institutions to implement informed strategies to minimize airborne risks, ensuring a safer learning environment

In the current context regarding energy sources’ problems, it is estimated that photovoltaic panels will produce a high percentage of waste that will put pressure on the environment. Thus, the study focuses on recycling them by incorporating them into mortars by four new mortar recipes (R1, R2, R3 and R4) that integrate photovoltaic panels’ dust (PVd) and pieces of photovoltaic panels (PVp), replacing the sand with PVd and PVp (1/3 to 100% of the total amount). All samples were subjected tensile bending and compression tests and were compared with the control sample (R0). As a result of the experimental research, a change in the apparent density of the proposed samples was found, and from the point of view of the tensile strength, R2 and R4 were found similar to sample R0 in both tests. The obtained results show that used photovoltaic panels can constitute raw material for the creation of new construction materials

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

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.

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.

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.