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Volumul 15 (2024), Nr. 3 - Vizualizare numar complet

Simulare numerica a incendiului: instrumente cheie in securitatea la incendiu pentru ingineria moderna
Numerical Fire Simulation: Key Tools in Fire Safety for Modern Engineering
Emanuil-Petru Ovadiuc, Ilinca Nastase, Razvan Calota

Fire simulation is a crucial tool in modern engineering for improving fire safety in constructions, especially in complex compartmental designs. It provides practical insights into structural fire behavior, the impact of combustible materials, and fire development, aiding in the formulation of effective fire safety measures. PyroSim, a graphical interface based on the Fire Dynamics Simulator (FDS), simplifies the creation and management of complex fire models. It supports file imports from AutoCAD DXF and DWG formats, offers background options from GIF, JPG, or PNG drawings, and includes tools for creating and validating multiple meshes. These simulations are essential for obtaining comprehensive data on various fire-related properties, such as temperatures, gas concentrations, smoke volume, pressures, and more, to ensure alignment with real-world conditions.

Keywords: Fire simulation, Modern engineering, 3D modeling, PyroSim, Combustible materials

Impactul Restrictiilor de Drept Public in domeniul constructiilor
The impact of Public Law Restrictions in the field of constructions
Alexandra-Paula Frent, Ana-Cornelia Badea, Petre Iuliu Dragomir, Gheorghe Badea

Increasing population density in urban areas in recent decades has led to the need to develop the building environment in an accelerated way, being necessary for the construction of buildings and their vertical development for a higher percentage of occupancy of the population on a small area of land. Urban expansion has determined the need to impose restrictions on public law through laws and regulations, to reduce the negative impact on the environment and to increase the quality of life of the population. Integrating restrictions, rights and responsibilities into cadastral systems would be an important step in developing integrated real estate management systems. This article aims to monitor the impact of public law restrictions on buildings in the urban area and to present urban regulations and legislation in Romania with applicability in the field of construction through the study of case in which a 3D model of representation and visualization of the restrictions of public law of the buildings is developed.

Keywords: Public Law-Restriction, 3D Cadastre, legislative framework, RRRs

Influenta ventilatiei cu recuperarea caldurii si a energiei solare in dimensionarea captatorilor de sol
The influence of ventilation with heat recovery, and solar energy in the sizing of soil collectors
Florin Vladimir Mihailov, Sebastian Parfene, Gratiela Tarlea

Prin pactul verde European se are in vedere ca pana in anul 2050 Europa sa devina neutra din punct de vedere climatic si al emisiilor de CO2. Sectorul rezidential contribuie la emiterea gazelor cu efect de sera in proportie de peste 39%, dintre acestea 28% reprezinta emisiile generate de consumul de energie pentru asigurarea conditiilor climatice ( incalzire, racire), iar 11% sunt emisii rezultate in urma proceselor tehnologice de fabricare a materialelor pentru constructii, un procent nedefinit il reprezinta consumul de energie pentru prepararea termica a hranei. Actiuni menite sa reduca emisiile gazelor cu efect de sera se duc in directia inlocuirii materialelor de constructii cu amprentă ridicata de CO2 cu materiale traditionale si cu un grad scazut de procesare, inlocuirea surselor de incalzire si racire mari generatoare de gaze cu efect de sera cu surse alternative, regenerabile, fara reducerea sau compromiterea confortului. Utilizarea pompelor de caldură, si in special a celor ce folosesc resursa geotermala, pentru incalzire si preparare apa calda menajera devine o solutie atractiva si determinanta în efortul de reducere a emisiilor gazelor cu efect de seră. Dimensionarea echipamentelor și implicit a captatorilor de sol, ( lungimea și numărul de foraje necesar funcționării) este o etapă preliminară stabilirii unui buget pentru realizarea investiției și tot o dată un factor decisiv în luarea unei decizii.

Cuvinte Cheie: pompa de caldura, resurse regenerabile,resursa geotermala, eficiența energetica, solutii traditionale

The European Green Pact aims to make Europe neutral in terms of climate and CO2 emissions by 2050. The residential sector contributes to the emission of greenhouse gases in a proportion of over 39%, of which 28% represent emissions generated by energy consumption to ensure climatic conditions (heating, cooling), 11% are emissions resulting from technological manufacturing processes of construction materials, and an undefined percentage represents energy consumption for the thermal preparation of food. Actions aimed at reducing greenhouse gas emissions go in the direction of replacing building materials with a high CO2 footprint with traditional materials and with a low degree of processing, and replacing large greenhouse gas-generating heating and cooling sources with alternative, renewable sources without reducing or compromising comfort. The use of heat pumps, and especially those that use geothermal resources, for heating and domestic hot water preparation is becoming an attractive and decisive solution in the effort to reduce greenhouse gas emissions. In order to set a budget for the investment and to make a decision, it is necessary to dimension the equipment and implicitly the soil collectors (the length and quantity of boreholes needed for operation).

Keywords: heat pump, renewable resources, geothermal resource, energy efficiency, traditional solutions

Reducerea concentratiei de compusi de valproat de sodiu in apa destinata consumului uman prin carbune activ
Reduction of sodium valproate compounds concentrations in water intended for human consumption by activated carbon
Khemis Oussama, Prof. Dr. Ing. Gabriel Racoviteanu

In our research project with the objective of reducing the pharmaceutical substance valproate sodium, it is aimed to reduce the concentrations of this pharmaceutical compound. Their water retention is carried out by several treatments and among these unconventional treatment methods such as: advanced oxidation, biological product with biomass, adsorption and catalytic oxidation suitable for this type of hulls. Due to the fact that part of the drugs are dispensed in pharmacies without a prescription, they are used and would be part of it, but also their metabolites end up in insurface water. Similarly, the intensive use of antibiotics and growth hormones in animal husbandry and the resulting insufficient treatment of surfacewaters by these elements. Pharmaceuticals are generally synthetic organic layers that are used for the purpose of improving animal and human health. Overuse of torah needles leads to their elimination andthe elimination of their metabolites through the urine. Similarly, dispensing without a prescription leads to the rare expiration of these substances which, when expired, mostly endup in the landfill. Internationally, there are studies of the risk posed by pharmaceuticals, their metabolites fromwater often intended for human consumption, and research into various means of reducing their concentration in water intended for human consumption. For the realization of the research project, studies will be reintegrated on laboratory facilities and pilot facilities of the water treatment laboratory of the Colentine laboratory complex, Faculty of Hydrotechnics. In this experimental research at colentina laboratory (romania) we 'to study the pharmaceutical substance valproate sodium with the treatment of adsorption by activated carbon at different concentrations (0.4, 0.8 and 1.6 mg/l) at two different flow rates (1.25 l/minand 2.5 l/min).

Keywords: pharmaceutical substance, valproate sodium, pollution of surface, adsorption

Influenta variabilitatii lungimilor datelor analizate asupra comportamentului distributiilor GEV si Pearson III
The influence of the analyzed data lengths variability on the behavior of the GEV and Pearson III distributions
Cristian Gabriel Anghel, Cosmin Craciun, Constantin Albert Titus, Cornel Ilinca

This manuscript presents the influence of the variability of the recorded data series on the behavior and generation of quantile values for two of the most used statistical distributions in the frequency analysis of extreme events in hydrology, namely the generalized extreme value (GEV) distribution and the Pearson III distribution. The methods for estimating the analyzed parameters are the method of ordinary moments and the method of linear moments, which represent two of the most used methods for estimating the parameters of statistical distributions. According to the results obtained, the L-moments method represents a more stable and robust method characterized by much smaller biases than the ordinary moments method, for quantile values in the field of rare and very rare events (low and very low annual exceedance probabilities).

Keywords: estimation parameters; method of ordinary moments; method of linear moments; Pearson III; GEV.

Explorarea aplicabilității și perspectivelor distribuției Pearson de tip III în analiza frecvenței inundațiilor
Exploring the Applicability and Insights of the Pearson Type III Distribution in Flood Frequency Analysis
Cristian Anghel, Stefan Ciprian Stanca , Cornel Ilinca

Being the parent distribution in Romania, the Pearson III distribution (PE3) is one of the statistical distributions that is most frequently used in flood frequency analysis (FFA). All the components required for the simple implementation of PE3 distribution in FFA are presented in this manuscript. The estimated methods and exact and approximate relationships for estimating the parameters and frequency factors particular to the distribution are described. All of these factors are used to identify maximum flows with various annual exceedance probabilities, using data collected at the 6 rivers with different morphometric characteristics and different lengths of data series. Five parameter estimation techniques are used in this comparative analysis, i.e. the method of ordinary moments (MOM), the method of linear moments (L-moments), the high-order linear moments method (LH-moments), the method of maximum likelihood (MLE) and the method of least squares (LSM). Given the results, it can be assumed that the L-moments approach is more reliable, stable, robust and less sensitive to variations in recorded data lengths, as well as to the presence of outliers.

Keywords: approximate form; confidence interval; estimation parameters; frequency factors; method of ordinary moments; method of linear moments; Pearson III

Evaluarea nivelurilor serviciului pentru drumuri din districtul central de afaceri (CBD) Akure, Nigeria
Assessment of the levels of service for roads in the Central Business District (CBD) of Akure, Nigeria
Adelakun Salami, Olufikayo Aderinlewo, Moses Tanimola

Traffic metering parameters in the CBD of Akure such as traffic composition and volume-capacity ratio were collected and evaluated to determine the levels of service of the selected major roads namely Oba Adesida road (directions A and B): direction A from Cathedral junction to ‘A’ Division and Direction B from ‘A’ Division to Cathedral junction and Arakale road (directions C and D): direction C from Isikan roundabout to NEPA roundabout and direction D from NEPA roundabout to Isikan Roundabout. The traffic composition analysis revealed the passenger car/taxi as the predominant mode while poor parking system, trading activities along the carriageway, bad roads, construction activities were identified as factors affecting the levels of service.

Keywords: Traffic metering; Levels of Service; traffic composition; volume-capacity ratio, junction.

Compozit usor din ghips cu incorporarea deseului de plastic pentru aplicatii in constructia cladirilor
Lightweight gypsum composite with plastic waste incorporation for building construction applications
Bogdan Valentin Paunescu, Enikö Volceanov, Marius Florin Dragoescu, Lucian Paunescu

Vizând fabricarea compozitului ușor pe bază de ghips a cărui rezistență mecanică să fie acceptabil de înaltă, lucrarea curentă a testat utilizarea combinată a expandat), precum și nanosilica, o foarte fină pulbere ca produs secundar al industriei metalurgice, având capacitatea de a îmbunătăți proprietățile mecanice ale compozitului. Combinația optimă a materialelor de umplutură a inclus PET (1 wt. %) și polipropilenă (1 wt. %) a căror structură fibroasă a influențat reducerea densității în vrac până la 540 kgꞏm-3, precum și, în mod special, creșterea rezistenței la încovoiere până la 4 MPa.

Cuvinte Cheie: compozit ușor din ghips, deșeu de plastic, pulbere de aluminiu, fibră, polimer

Aiming at making lightweight gypsum-based composite whose mechanical strength to be acceptably high, the current work tested the combined use of some recycled plastic waste (polyethylene terephthalate-PET, polypropylene, and expanded polystyrene) as well as silica fume, a very fine powder as by-product in metallurgical industry, having the ability to improve the composite mechanical properties. The optimal combination of fillers included PET (1 wt. %) and polypropylene (1 wt. %) whose fibrous structure influenced the decrease of bulk density up to 540 kgꞏm-3 as well as especially the increase of flexural strength up to 4 MPa.

Keywords: lightweight gypsum composite, plastic waste, aluminum powder, fiber, polymer

Studiul durabilitatii pamantului stabilizat pe baza de sedimente reciclate
Study of the durability of stabilized earth based on recycled sediment
Nezha Gueffaf, Bahia Rabehi, Noureddine Mesboua, Khaled Boumchedda

The durability of blocks made by earth can be improved considerably by the addition of different stabilizers. In this work, two stabilizers have been used: cement. The elaborated specimens are evaluated by various laboratory tests, and durability is evaluated by examination of walls exposed to real climatic conditions. It has been noted that all treated walls showed no signs of deterioration after 2 years exposure in real climatic conditions even though the laboratory test conditions are more severe compared to the natural climatic conditions of the region of Algiers where this present work has been carried out. The blocs stabilized by cement showed the best durability behavior.

Keywords: Recycled Sediment; Stabilizers; durability tests; Climatic conditions exposure

Impactul sistemelor HVAC geotermale de mică adâncime cu pompe de căldură asupra apei subterane și solului
The impact of shallow geothermal HVAC systems with heat pump units on the ground and ground water
Razvan–Silviu Stefan, Daniel Cornea

The paper presents the study conducted to determine the impact of HVAC geothermal systems with heat pumps units on the ground and groundwater. Due its very complexity the HVAC geothermal system with heat pumps units that equips the ELI-NP research infrastructure could be a suitable tool to determining the long-term impact of shallow geothermal systems on the environment. The system has been continuously operating and monitored for 5 years.

Keywords: HVAC, heat pumps

Solutii pentru eficienta energetica a cladirilor situate in apropierea cursurilor de apa prin integrarea SRE. Studiu de caz
Solutions for the energy efficiency of buildings located near watercourses through SRE integration. Case Study
Daniel Muntean, Danut Tokar, Adriana Tokar, Daniel Bisorca, Alexandru Dorca

Currently, approximately 40% of the energy demand in the European Union (EU) is used in buildings and the energy demand for cooling and heating is increasing every year, so the energy efficiency of buildings represents a problem of increased interest and of extreme relevance. The article proposes, through the case study, the installation of a photovoltaic system for the production of electricity on the roofs of the buildings and the cooling and heating of the building using a water-to-water heat pump. Having the advantage of the location of the studied buildings on the banks of the river Bega in the town of Timisoara, the case study proposes the cooling of the spaces in the buildings in two variants, namely in the spring and autumn when the outside temperature is not very high using the river water directly ("free cooling"), and in the summer for the hot months, a water-to-water heat pump to cool the cooling agent to the parameters necessary to achieve a proper air conditioning.

Consideratii privind valorificarea energiei reziduale pentru incalzirea/racirea cladirilor si prepararea apei calde de consum menajer.
Considerations regarding the recovery of residual energy for the heating/cooling of buildings and the preparation of domestic hot water
Adriana Tokar, Daniel Bisorca, Daniel Muntean, Danut Tokar, Marius Adam, Cristian Pacurar, Alexandru Dorca, Andreea-Nicoleta Cainicianu

Currently, many opportunities for real energy and cost savings are missed, primarily due to the perception of quantitative heat recovery. However, in the context of the need for the energy efficiency of buildings and technological processes, the recovery and valorisation of residual energy will be a key element. For this reason, the article analyses the recoverable potential from residual energy from various sources and proposes a way to capitalize on it for heating/cooling buildings and preparing domestic hot water.

Keywords: residual energy, recovery, heating/cooling, domestic hot water

Optimizarea sistemelor de conversie a energiei eoliene
Optimization of wind energy conversion systems
Danut Tokar, Adriana Tokar, Daniel Muntean, Daniel Bisorca, Alexandru Dorca, Marius Adam

In close connection with the issue of global security, the issue of ensuring energy resources has been put on the table of consumers and producers of various forms of energy, researchers, but especially politicians and social planners. Ensuring energy independence was put into question after the onset of the oil crisis in 1973, thus the various energy sources and their associated technologies are gradually being replaced by new technologies that integrate renewable energy sources, capable of taking over at an increased level of efficiency the energy requirement.

Keywords: optimization, storage, energy, wind, RES,

Modelare prin simulare dinamica (DSM) pentru performanta energetica a cladirilor si selectia echipamentelor HVAC. Studiu de caz.
Dynamic Simulation Modeling. (DSM) for Building Energy Performance and HVAC Equipment Selection. A Case Study
Andrei Duna

The paper presents a case study in which a dynamic simulation modeling (DSM) calculation was carried out to assess the energy performance of a building in Giroc, a locality adjacent to the city of Timișoara, using the VABI Elements software. The characteristics were determined based on which the HVAC equipment was selected

Keywords: VABI Elements, dynamic simulation, DSM, envelope, parameters, buildings, cooling demand, heating demand

Analiza solutiilor ingineresti implementate pentru un hotel
Analysis of engineering solutions implemented for a hotel
Vera Danici-Gutul, Vladimir Grebinicenco, Vera Guțul

The purpose of this paper is to analyses the solutions for the heating and domestic hot water supply system for a modernized hotel in the city of Chisinau for the climatic conditions of the Republic of Moldova. In the paper, the implemented solutions were analyses, the investment recovery term was determined. The Republic of Moldova does not have its own energy sources, and the need to implement alternative sources is obvious. In this sense, the use of heat pumps, photovoltaic panels form an energy efficient, economical and more ecological system than any thermal energy generating installation.

Keywords: heating, domestic hot water, heat demand, heat pumps, photovoltaic panels

Strategii pentru atingerea unei amprente de carbon net-zero in sistemele de canalizare si epurarea apelor uzate
Strategies for Achieving a Net-Zero Carbon Footprint in Wastewater Systems
Cristina Iacob, Anagabriela Deac, Dan Muresan, Andrei Bolboaca, Teodor Chira

The world is currently undergoing a transition from a linear economy to a circular one, with the wastewater sector offering numerous opportunities for decarbonization and mitigating the impacts of climate change. Urban wastewater systems are significant sources of greenhouse gas emissions, highlighting the need for a shift towards net-zero carbon states. This paper aims to provide insights into minimizing carbon footprints and achieving net-zero carbon conditions in wastewater systems by examining sources of GHG emissions and exploring effective mitigation strategies. Strategies for decarbonization include operational optimization, energy and resource recovery, source separation systems, and decentralization. Implementing these strategies is crucial for reducing the impacts of climate change and achieving sustainability goals in wastewater systems.

Keywords: wastewater systems, wastewater treatment, GHG emissions, mitigation, strategies, carbon footprint, climate change

Trecerea la alternative cu GWP scazut in refrigerarea comerciala
Shifting to low GWP alternatives in commercial refrigeration
Adrian Mihai

Adoption of the new regulation 2024/573 of the European Parliament and of the Council, due to the increase in global warming, commercial refrigeration adapts, together with the reduction of the possibility of using refrigerants with a GWP greater than 150 units starting from 2025. In this way, the transition to refrigerants with GWP less than 150 units becomes mandatory for manufacturers of stationary refrigeration equipment. Refrigerants with GWP below 150 units are from category A2L (slightly flammable refrigerants) and A3L (flammable refrigerants) and this implies greater safety measures in installation and service than in the case of refrigerants from category A1L (nonflammable refrigerants).

Keywords: commercial refrigeration, low GWP, A2L refrigerants, A3L refrigerants

Despre evaluarea coeficientului de performanta al unei pompe de caldura
About the evaluation of the coefficient of performance for a heat pump
Florin Iordache, Florin Baltaretu, Alexandru Draghici

The present work represents a continuation of our research in the field of evaluating the thermal efficiency (coefficient of performance) of a heat pump, research started and published in 2019 [1]. In the previous work it was considered the refrigerating machine, this time we will refer exclusively to the mechanical vapor compression heat pump. The evaluation of the COP for a heat pump is absolutely mandatory in the calculation procedure of contribution of the renewable resources of energy, offered by the implementation of a heat pump in the thermal utility supply systems in buildings (space heating and/or hot water preparation).

Keywords: heat pump, efficiency

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