Iraqi Journal of Industrial Research

The improvement of the performance of thermal systems is an important task in today's energy industry, for example, in solar collectors and solar heat exchangers. The enhancement of heat transfer and fluid dynamics inside different channel geometries is therefore of high technological and scientific interest. In this regard, exploitation of nanofluids has gained attention as an alternative strategy to improve thermal performance, as they possess better thermophysical properties. Current work is based on computational fluid dynamics (CFD) tools (Ansys Fluent) to enhance the heat transfer and the flow behavior of water by ZnO nanoparticles, also known as zinc oxide. Nanoparticles of zinc oxide (ZnO) are dispersed in the water at varying concentrations (0.4% and 1.3%) in a channel having a square cross section. The bottom face is maintained under a constant heat flux of 50kW/m² and the rest of the walls are thermally insulated. The flow is assumed to be turbulent, single-phase, steady, 3D, and occurring in the range of Reynolds number from 4000 to 12000. The results indicate that the incorporation of ZnO nanoparticles can effectively enhance heat transfer, and the heat transfer coefficients increase by 23.79% and 28.10% when the volume fractions are 0.4% and 1.3%, respectively. In addition, the friction factor is reduced with a higher Reynolds number and by adding nanoparticles. These results indicate that not only can ZnO nanofluids greatly enhance the system performance.

Aluminum composite panels (ACPs) are extensively utilized in building facades, but need drilled holes for screw fixation, exposing them susceptible to environmental stresses. This study examines the impact of wind speeds (8–18.72 m/s) on the fatigue life of ACPs. Tensile and fatigue tests were performed on pristine specimens and panels featuring holes of 2, 3, and 4 mm in diameter. The experimental results indicated a significant decrease in fatigue endurance limits (after 10⁶ cycles), from 2.3 MPa for the unaltered specimen to 1.45 MPa, 1.424 MPa, and 1.37 MPa for the specimens with 2, 3, and 4 mm holes, respectively. ANSYS Workbench simulations analyzed a 1 m² ACP subjected to wind pressure to identify fatigue safety factors. This research determined the safe wind speed thresholds (with a safety factor of 1.25) as 14.41 m/s (pristine), 11.20 m/s (2 mm), 11.12 m/s (3 mm), and 10.79 m/s (4 mm). Results from experiments indicated fatigue limits of 2.3 MPa (pristine), 1.45 MPa (2 mm), 1.424 MPa (3 mm), and 1.37 MPa (4 mm). The pristine specimen exhibited superior fatigue resistance due to the absence of stress concentrations. Dynamic study indicated safe wind speeds of 14.41 m/s (pristine), 11.2 m/s (2 mm), 11.12 m/s (3 mm), and 10.79 m/s (4 mm). Hole diameter directly reduces fatigue performance and allows wind loads. The existence of a 4 mm aperture diminished the fatigue endurance limit by roughly 40% and the safe wind speed threshold by 25% in comparison to the unblemished panel.

Wireless mesh networks (WMNs) are crucial for enabling communication without fixed infrastructure in various scenarios such as disaster response, rural connectivity, and educational experimentation. Although the Optimized Link State Routing (OLSR) protocol is widely studied in the research community, practical deployment reports remain limited and fragmented. This paper presents a clear and reproducible methodology for deploying OLSR (using OLSRd, a routing daemon that installs and updates routes in the Linux kernel) on embedded Linux systems, namely OpenWRT running on Raspberry Pi 3B+ devices. In addition, a Multi-Criteria Decision Analysis (MCDA) framework is applied to evaluate four distinct routing protocols (OLSRd, BATMAN, Babel, and HWMP) based on usability, configuration complexity, GUI support, documentation quality, and hardware compatibility. Experimental tests are conducted to measure network performance in terms of latency, throughput, and convergence time. Four case studies are also presented to show protocol suitability in different contexts, including community networks, IoT deployments, disaster simulations, and industrial environments. The results conclusively show that OLSRd is the most deployment-friendly protocol, combining procedural simplicity with reliable performance. This study provides practical guidance and valuable technical references for researchers, educators, and practitioners working on wireless mesh testbeds with embedded platforms, ultimately aiming to bridge the gap between academic theory and real-world application.

Corrosion represents one of the major challenges confronting companies under the Ministry of Industry and Minerals, including the General Company for Electrical Industries, which manufactures electric water heaters typically made of galvanized iron. During the production process, components of the heater are joined using arc welding, where the heat generated during welding causes the removal of the galvanization layer in the welded areas. This results in the development of electrochemical potential differences between galvanized and non-galvanized regions, leading to the formation of localized anodic and cathodic zones. Consequently, electrochemical reactions are initiated, involving the flow of electrons from the anodic to the cathodic regions in the presence of a conductive medium (water), thereby accelerating the corrosion process in the welded zones. In this research, a linear polarization system (Potentiostat MLab-200) was employed to measure the corrosion current density (Icorr) and corrosion potential (Ecorr), followed by the calculation of corrosion rates at various temperatures 30, 40, 50, 60, and 70°C under conditions simulating the actual operation of an electric water heater. The results indicated that the corrosion rate of galvanized iron prior to welding was approximately 2.0 mpy at 70 °C, whereas it increased to 3.0 mpy after welding at the same temperature. To mitigate this corrosion, a sacrificial zinc anode was introduced into the heater system, which reduced the corrosion rate to 1.9 mpy at 70°C. This implementation contributed to prolonging the service life of the heater and enhancing its operational efficiency.

Air pollution in Erbil, Kurdistan Region of Iraq, has increased significantly in recent years, due to rapid urbanization, increased vehicular emissions, industrial activities, and the use of low-quality fuels. This study assessed the monthly variation of key air pollutants in Erbil, Iraq, over a 12-month period, focusing on carbon monoxide (CO), formaldehyde (HCHO), methane (CH₄), nitrogen dioxide (NO₂), ozone (O₃), sulfur dioxide (SO₂), and ultraviolet (UV) radiation. The data analysis revealed that CO concentrations ranged from 5.90 ppm in October to 7.42 ppm in June, with a mean of 6.66 ppm. Formaldehyde levels varied between 0.0124 ppm and 0.0382 ppm, peaked in summer months, while methane showed minimal variation around 4.67 ppm. Nitrogen dioxide ranged from 0.0512 ppm to 0.1004 ppm, with higher levels observed in warmer months. Ozone concentrations fluctuated between 0.2997 ppm and 0.3684 ppm, exceeding WHO guidelines throughout the year. Sulfur dioxide showed significant seasonal variability, rose to 0.0232 ppm in December. The UV index varied markedly, with a maximum of 16.76 in January and a minimum of 6.35 in June. Regression analysis revealed significant negative trends for CO and UV, while HCHO, CH₄, and SO₂ revealed increasing trends over time. Air Quality Index (AQI) values indicated consistently high levels of O3 and NO2 reached hazardous levels. Correlation and principal component analyses identified CO and NO2 as the primary contributors to air pollution. The findings demonstrated notable seasonal and spatial variability, with pollutant concentrations frequently exceeding WHO limits, highlighting the urgent need for effective air quality management in Erbil.

Other cellulosic substances like wood are highly appreciated in the construction and furniture manufacturing businesses because of their beauty, durability and being a friendly environment. Nonetheless, they are very flammable and their use raises serious issues of fire safety, both at residential and commercial places. This review takes a critical look on the developments of fire retardant treatment in raising the fire resistance of wood and cellulosic materials. The study investigates extensive variety of treatments by formulation, such as well-established chemical retardants and the newer and greener products, whose mechanisms action and levels of flame reduction, thermal decomposition and smoke generation are discussed. The study integrates the results of experimental studies published in the last two years, traces of industry studies, and studies presented in scientific literature to compare the effect of these treatments on their comparative performance, on environmental impact, and implications on structural integrity. Use of sustainable and low toxic solutions is especially focused on ensuring that they meet the requirements of green buildings. This study summarized the existing knowledge in order to find the most promising method to increase the fire safety of wood-based products that favor the environmental and structural performance. The results can be useful to material scientists, engineers, and policy makers who occupy themselves with developing safer and more sustainable construction materials and fire resistant furniture applications.

Six nickel alloys (Ni3Al, NiAl, Ni90Cr10, Ni80Cr20, Ni35Cr20Fe45, and Ni60Cr16Fe34) varied in their chemical formulas, mole fractions (%) of each element, density, and Mean Atomic Number (Z ̅), alongside other chemical-physical properties were subjected to a prediction study depending on using NGCal and Phy-X software. Both free and friendly attenuation prediction software were chosen to calculate the attenuation factors against Neutron, Gamma radiation, and X-rays exposure. The calculated factors included Linear Attenuation Coefficient (LAC), Mass Attenuation Coefficient (MAC), Half and Tenth Value Layer (HVL and TVL), and Mean Free Path (MFP) by both Phy-X and online NGCAL software. NGCAL software was utilized to study the effect of photons at (0.1, 1, 15) MeV and neutrons [fast at 4 MeV and thermal at 25.4 meV). By using Phy-X software, energy range was (0.015-15) MeV, characteristic X-rays (Kα, Kβ) included 29Cu, 37Rb, 42Mo, 47Ag, 56Ba, and 65Tb and radioactive isotopes were Am-241, Ba-133, Cd-109, Cs-137, Co-60, Eu-152, Fe-55, Na-22, and I-131. Additionally, protection efficiency (%) of each nickel alloy was calculated based on Lambert – Beer law by applying different thicknesses. The main aim of this prediction study is to provide workers that deal with Neutron, Gamma radiation, and X-rays particularly in the research, medical, industrial, and petroleum sectors most effective nickel alloy as a safe shielding material especially at high exposure energies. Both mathematical models indicated that Chromel (Ni90Cr10) as the highest density and high Nickel mole fraction exhibited the highest protection efficiency.

The large-scale contamination of water resources by antibiotics, particularly tetracycline (TC), represents a massive threat. In the present study, the synthesis, characterization, and application of chitosan/Ag2O NP biocomposites as efficient adsorbents for the elimination of TC from aqueous solutions were investigated. Silver oxide nanoparticles (Ag2O NPs) were synthesized using the co-precipitation method and incorporated into a chitosan matrix to enhance adsorption capacity. The resulting biocomposite was characterized using Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and atomic force microscopy (AFM) to evaluate its structural, morphological, and functional properties. Adsorption parameters such as adsorbent mass, contact time, initial concentration, and temperature were systematically studied. The maximum adsorption capacity of 51.422 mg/g was achieved at 303 K after 60 min using 0.08 g of the synthesized composite. Adsorption isotherm data were analyzed using the Freundlich, Temkin, and Langmuir models, with the results showing better agreement with the Temkin and Freundlich models. Furthermore, temperature played a significant role, as the removal efficiency decreased with increasing temperature, confirming the exothermic nature of the adsorption process. Thermodynamic analysis further supported this observation, with negative ΔH° (–23.75 kJ/mol) indicating an exothermic process, positive ΔG° values (+4.08 to +5.93 kJ/mol) indicate non-spontaneity under the studied conditions, and negative ΔS° values (–90 to –92 J/mol.K) reflecting decreased randomness at the solid–liquid interface during adsorption.

This study utilized multiple materials to protect workers, particularly those in oil fields, from radiation hazards, including gamma rays. Each sample from the eight tantalum oxides: Mn2+Sn4+Ta2O8, Mn2+Ta2O6, Fe2+Ta2O6, Fe2+Ta2O6, (Y,U,Fe2+)(Ta,Nb)(O.OH)4, Bi(Ta,Nb)O4, (Ca,Na)2(Ta,Nb)2O6F, and Al4Ta3O13(OH) were evaluated as shields from the harm of gamma rays. All these materials are natural and insoluble in water. Here, the potential of using tantalum oxides mainly depends on the chemical composition of each material and its density, as well as their effectiveness in mitigating ionizing radiation. The calculated gamma ray shielding parameters include the linear attenuation coefficient, mass attenuation coefficient, half value layer, tenth value layer, mean free path, effective electron density, effective conductivity, and atomic cross-section. Electronic cross section, effective atomic number, and equivalent atomic number. These parameters were obtained by applying free Phy-X software within the photon interaction range of 0.015-15 MeV. The linear attenuation coefficient and mass attenuation coefficient decreased as the energy increased, whereas the other shielding parameters decreased as the energy decreased. Among all the tested samples, bismutotantalite Bi(Ta,Nb)O4 proved as the most effective material for gamma-ray shielding because of its heavy element content, high mean atomic number, and highest density, which are the key factors at intermediate energies (Compton effect). In contrast, materials such as {(Ca,Na)2(Ta,Nb)2O6F, Al4Ta3O13(OH), (Y,U,Fe2+)(Ta,Nb)(O. OH)4}, which contain lighter elements were less effective in protection from this radiation. At high photon energies, pair production occurs; consequently, these lighter materials do not strongly absorb radiation.

Over the past decade, hybrid encryption techniques have gained prominence for their ability to combine the strengths of different cryptographic algorithms. This study presents a performance evaluation of four hybrid schemes RSA with AES, RSA with ChaCha20, ECC with AES, and ECC with ChaCha20 implemented in Java and tested for secure data transmission across cloud services, e-applications, and IoT platforms. Performance is assessed based on key generation time, encryption/decryption speed, and memory usage across various file types. The results indicate that ECC-based combinations significantly outperform RSA based methods, both in computational speed and resource efficiency. Among these, the hybrid ECC with ChaCha20 algorithm demonstrates the fastest processing times and the lowest memory consumption, making it particularly suitable for mobile and embedded systems with limited resources. While ECC with AES offers comparable memory efficiency, its encryption speed is slightly lower. In contrast, RSA-based hybrids, though cryptographically secure, exhibit higher processing demands, rendering them less practical for high-performance or real-time applications. The study underscores the advantages of leveraging ECC with modern stream ciphers such as ChaCha20 to achieve a balance between security and system efficiency. These insights offer valuable guidance for engineers and researchers developing secure communication systems in resource-sensitive environments.