Given the energy crisis the entire planet is going through, the waste of any form of fuel or energy source is clear evidence of irresponsibility towards both humanity and the planet we manage. The study presents several proposals for making the district heating system more efficient by integrating renewable sources into the heat production process and recovering the residual thermal energy resulting from technological processes.

Keywords: renewable energy sources, district heating, waste energy recovery

Studiul de față investighează valorificarea deșeurilor textile și a celor pe bază de celuloză prin obținerea unor materiale compozite sustenabile. Deșeurile textile postconsum (bumbac, poliester și amestecuri) au fost combinate cu reziduuri de hârtie și carton pentru a produce panouri decorative, cărămizi, plăci compozite, hârtie manuală, compost, etc. Procesele de fabricare au inclus presarea, turnarea, extrudarea și macerarea, utilizând lianți ecologici și aditivi minerali pentru îmbunătățirea proprietăților mecanice, termice și de rezistență la foc. Caracterizarea materialelor a cuprins determinarea conductivității termice, a rezistenței la compresiune, analiza morfologică și evaluarea estetică. Rezultatele indică faptul că produsele reciclate prezintă performanțe comparabile cu cele ale materialelor convenționale, oferind o bună izolație termică și acustică, rezistență la foc și emisii reduse. Abordarea propusă reprezintă o soluție viabilă de economie circulară, contribuind la reducerea cantității de deșeuri depozitate și la conservarea resurselor naturale

Cuvinte Cheie: textile, deșeuri, celuloză, reciclat, produs

The present study investigates the valorization of textile and cellulose-based waste through the production of sustainable composite materials. Post-consumer textile waste (cotton, polyester, and blends) was combined with paper and cardboard residues to produce decorative panels, bricks, composite boards, handmade paper, compost, and industrial absorbents. The manufacturing processes involved pressing, molding, extrusion, and maceration with eco-friendly binders and mineral additives to enhance mechanical, thermal, and fire-resistant properties. Characterization included thermal conductivity, compressive strength, morphological analysis, and aesthetic evaluation. Results indicate that the recycled products exhibit comparable performance to conventional materials, offering good thermal and acoustic insulation, fire resistance, and low emissions. The approach provides a viable circular economy solution, reducing landfill waste and conserving natural resources.

Keywords: textile, waste, cellulose, recycled, product

Riscul seismic din România generat în principal de producera unor cutremure relativ rare, dar foarte severe, cu potențial ridicat de pierderi structurale și socioeconomice. În mod tradițional, reducerea riscului seismic a fost abordată în principal prin măsuri structurale, însă conceptul de reziliență seismică implică și capacitatea de recuperare după producerea evenimentului. Lucrarea analizează rolul asigurărilor ca instrument financiar în creșterea rezilienței seismice, cu accent pe contextul românesc. Pe baza analizei riscului seismic, a pierderilor potențiale și a nivelului actual de asigurare, este evidențiat decalajul existent între pierderile așteptate și capacitatea de compensare. Sunt subliniate necesitatea unor strategii integrate care să coreleze reducerea vulnerabilității structurale cu mecanismele financiare de transfer al riscului.

Cuvinte Cheie: risc seismic, reziliență seismică, asigurări, pierderi seismice

Seismic risk in Romania is mainly triggered by relatively rare but very severe earthquake events capable of generating significant structural damage and socio-economic losses. While traditional seismic risk mitigation has focused primarily on structural measures, increasing attention is being paid to the concept of seismic resilience, which also includes post-event recovery capacity. This paper discusses the role of insurance mechanisms as a financial component of seismic resilience, with emphasis on the Romanian context. By analysing seismic risk characteristics, expected losses and the current level of insurance coverage, the study highlights the existing protection gap and the limitations of current approaches. The paper argues for integrated strategies combining structural risk reduction and financial risk transfer to enhance seismic resilience.

Keywords: seismic risk, seismic resilience, insurance, earthquake losses

This paper adapts the pressure-based algorithm of EPANET 2.2 to comply with national plumbing standards under different operating contexts. The study focuses on calibrating the discharge coefficient (C) and pressure exponent (γ), which govern flow behavior in pressure-driven conditions. Case studies in Algeria and Romania demonstrate how regulatory provisions influence these parameters, with γ converging around 0.6 and C varying according to building typologies. Results highlight the advantages of Pressure Driven Analysis (PDA) over Demand Driven Analysis (DDA), offering more realistic simulations for water distribution networks.

Keywords: water distribution system, calibration, simulation, demand driven analysis, pressure driven analysis, EPANET

The purpose of this article is to provide an overview of the environmental effects that may influence the durability of concrete structures in nuclear power plants. Over time, the properties of concrete change as a result of the evolution of microstructural processes as well as under the action of environmental factors. These transformations are not necessarily severe enough to compromise the ability of concrete to meet its performance requirements. However, under certain conditions, concrete may experience undesirable deterioration due to inadequate specifications, noncompliance with those specifications, or unfavorable behavior of the cement paste or aggregate constituents as a result of physical or chemical actions

Keywords: Nuclear structures, concrete, high temperatures, radiation, corrosion, durability, concrete shrinkage

The study assesses the characteristics of urban traffic flow along Oba Adesida Road, Akure, Nigeria, using a combination of field data and Simulation of Urban Mobility (SUMO). Physical measurements of the roadway were obtained, and a seven-day traffic count was conducted from 7:00 a.m. to 7:00 p.m. using videographic and manual methods. Vehicle volumes were converted into Passenger Car Units (PCU) using the British standard equivalence method. SUMO simulation was applied to replicate the observed conditions, enabling comparison between field and model outputs. Results indicate that the corridor is dominated by taxis, motorcycles, tricycles, and buses, with peak volumes ranging from 1080 to 2221 PCU/hr and daily totals between 13,908 and 25,788 PCU/day. The simulation closely matched field observations, with a mean deviation of about 10%. The findings highlight significant congestion patterns during morning and evening peaks, providing a basis for improving traffic management strategies in Akure.

Keywords: Urban Traffic Flow, SUMO Simulation, Passenger Car Unit, Traffic Congestion, Akure City

This paper explores the methodology and implications of transforming traditional cadastral plans into three-dimensional digital models using complementary software tools such as GIMP, ArcGIS Pro, ArcGIS CityEngine, and Python. The research addresses the growing need for digitization in Romania’s cadastral system, highlighting both technological opportunities and legislative challenges. A step-by-step workflow is proposed, from preprocessing scanned cadastral maps to generating realistic 3D city models. The study demonstrates the added value of 3D models for urban planning, heritage conservation, infrastructure design, and public consultation. Recommendations are made for standardizing practices and aligning Romania’s approach with European and international best practices.

Keywords: GIS, 3D models, cadastral plans

We introduce a performance-based playbook for cutting the environmental footprint of reinforced concrete while keeping structural reliability and service life intact. The method explicitly couples life-cycle indicators (e.g., Global Warming Potential) to durability-verified choices of materials and detailing. Exposure-calibrated mix designs guided by Exposure Resistance Classes (ERC) are paired with optimized blended cements and complemented by alternative binders, fibers, and corrosion-resistant reinforcement. Illustrative applications indicate meaningful CO₂ abatements alongside compliance with mechanical and durability targets, providing a practical, auditable route to sustainable structural concrete.

Keywords: sustainability; reinforced concrete; durability; blended cements; geopolymers; performance-based design

To be able to induce a controlled transient flow in the Boundary Layer Wind Tunnel by modifying the frequency of the current supplied to the axial fan, the response time of the system to different step functions imposed on the frequency must be determined. Several experiments were performed for different steps of the frequency and different heights of the roughness above the tunnel floor. Measurements were performed for 4 increasing frequency steps for two different heights of the roughness on the wind tunnel floor and consisted in velocity and pressure values at different cross sections along the tunnel.

Keywords: Axial fan; Variable Roughness; Transient flow

This paper investigates current challenges in the design and operation of sprinkler fire extinguishing systems, especially regarding the extrapolation of droplet distribution from standard diagrams, positioning and spacing between sprinkler heads in complex geometries, air current influences, and heat release variations. Through theoretical studies, simulation models and experimental measurements with laser-based droplet size analysis, solutions for system optimization are proposed. Key recommendations address the use of CFD tools, adapted sprinkler types, and refined placement strategies to enhance sprinkler efficiency.

Keywords: Fire suppression, sprinkler systems, droplet size, CFD simulations, performance evaluation

The impact of sleep quality on overall health is significant thus it is necessary to maintain the standards for air quality in civilian buildings. Student accommodations often lack these standards especially in thermal comfort, lighting and air quality. This study shows improper CO2 concertation in newly built student dormitories that have an effect on both mental and physical health The study shows that CO2 concentrations are above average (≈1278 CO2 ppm) especially during nighttime correlated with thermal discomfort caused by lack of proper ventilation in the sleeping and studding area.The collaboration between the medical and engineering field is important in order to maintain proper standards for air quality that will in turn also decrease several afflictions and risk of diseases.

Keywords: air quality; CO2 concertation; health effects

Given the critical global context that has been reached in terms of air pollution caused by carbon emissions and other pollutants resulting from the combustion of conventional fuels, we urgently need to reduce the impact on the environment and find solutions that slow down global warming. Energy in various forms is a need that we cannot do without, but we must resort to primary sources that are as less polluting as possible and that at the same time ensure energy demand. Renewable energy sources must be exploited to the greatest extent possible and installations/equipment optimized for the highest possible efficiency. This paper presents the main conventional and unconventional energy sources, the evolution of their use over time and proposals for optimizing thermal and electrical energy production systems.

Keywords: fossil fuels, natural gas, district heating systems, renewable energy sources, heat pumps

A fost testat un material de construcție alternativ termoizolant pe bază de spumă de lemn. Tipul de lemn adoptat a fost lemnul de stejar, neutilizat până în prezent, conform datelor din literatura de specialitate. Obiectivul lucrării a fost înlocuirea materialelor plastice, utilizate în mod obișnuit la fabricarea materialelor izolatoare. Amestecul a inclus deșeu de lemn măcinat, un surfactant adecvat (dodecilsulfat de sodiu) și apă distilată. Suspensia umedă obținută a fost expandată prin agitare și uscată la 80 ℃. Proprietățile fizico-termice au fost remarcabil de performante, în timp ce rezistența la compresiune a atins doar valori scăzute, dar acceptabile pentru scopul dorit. Rezultatele au fost similare cu cele raportate în literatura de specialitate pentru alte tipuri de spumă de lemn

Cuvinte Cheie: spumă de lemn, lemn de stejar, surfactant, densitate mică, conductivitate termică.

An alternative heat-insulating building material based on wood foam was tested. The adopted wood type was oak wood unused until now, according to data from the literature. The work objective was replacing plastics, commonly used in manufacturing insulating materials. The mixture included ground wood waste, an adequate surfactant (sodium dodecyl sulfate), and distilled water. The obtained wet suspension was expanded by stirring and dried at 80 ℃. The physical-thermal properties were remarkably performant, while compressive strength reached only low values, but acceptable for the desired purpose. Results were similar to those reported in the literature regarding other wood foam types.

Keywords: wood foam, oak wood, surfactant, low density, heat conductivity

The paper provides an overview of current studies on 3D concrete printing, highlighting its transformative impact on traditional construction methods. It begins by reviewing advancements in materials specifically tailored for this technology, including fibers, binders, aggregates, additives, and admixtures essential for printed concrete. The article notes that 3D concrete printing requires special mortars that facilitate extrusion, set rapidly, and ensure strong mechanical performance while minimizing environmental impact. The focus is on the unique properties of these materials, differing from conventional concrete, such as rheology, durability, rapid setting, and a reduced carbon footprint, which are critical for additive manufacturing processes. Despite technological progress, challenges remain regarding the long-term mechanical behavior, material durability, and process consistency of 3D printed elements. The conclusion underscores the need for further research to overcome these obstacles and asserts that 3D concrete printing represents a promising pathway toward more automated, adaptable, and sustainable construction practices.

Keywords: 3D concrete printing, fiber reinforcing, the materials, technological advancements, material durability

Ensuring the safety of large dams is a legal and ethical obligation that requires continuous assessment of structural behaviour and associated risks. This study proposes a decision-based framework for risk reduction through dedicated behaviour monitoring systems (BBM), emphasizing their role in detecting atypical responses and preventing potential failures. A quantitative method is developed to evaluate the effectiveness (r) of supplementary monitoring interventions by correlating reductions in failure probabilities across distinct failure mechanisms. The framework is applied to the Vidraru Dam (Romania), a concrete arch dam undergoing refurbishment, including a full filling–emptying operational cycle. Historical behaviour data and previous emptying events are reviewed to identify specific vulnerabilities related to thermal, hydraulic, and structural stress variations. Multiple supplementary monitoring options—mathematical modelling, telemeter reactivation, 3D laser scanning, InSAR tracking, hydrogeological boreholes, and inclinometer casing are evaluated based on risk reduction efficiency, implementation cost, and net benefit. Results show that a combined strategy integrating finite element modelling, telemetric upgrades, 3D scanning, and hydrogeological instrumentation yields the optimal balance between safety and cost- effectiveness, achieving the greatest reduction in annual risk rate. The proposed methodology provides a systematic approach for decision-making in dam safety management under atypical operating conditions.

Keywords: dams, safety, BBM