Iranian Journal of Chemistry and Chemical Engineering
Volume:44 Issue: 3, Mar 2025

This study investigates sodium nitrate nanoparticles' nucleation and induction time in the presence of Sodium Dodecyl Sulfate (SDS) as a surfactant during reactive crystallization. The primary objective was to assess how varying super-saturation levels and SDS addition influence the induction time and nucleation process. Experiments were conducted at 25°C, and the induction time was measured for different sodium nitrate concentrations and surfactant amounts. The results revealed that increasing super-saturation reduced induction time, aligning with the classical nucleation theory. Additionally, the presence of SDS altered the nucleation process, with its effect being most pronounced at higher super-saturation levels. While SDS did not prevent nitrate adsorption onto the crystal surface, it accelerated the process by forming complexes within the solution. These complexes, larger and slowerto penetrate, reducing the nucleation speed. At lower concentrations, the solution exhibited faster penetration and shorter induction times. The study demonstrates that SDS and super-saturation significantly impact induction time, with a positive correlation between nucleation rate and super-saturation. This research provides new insights into the nucleation behavior of sodium nitrate nanoparticles and the role of surfactants in the crystallization process, contributing to the optimization of nanoparticle production methods.

Despite major advances in treatment options over time oral cancer remains a major global health problem because of its high death rates and the scarcity of effective treatments. This makes it vital to find targeted therapies to improve patient outcomes. This research looks at how the cholesterol-lowering drug bezafibrate might cause cell death in human oral cancer cells using protein analysis to study the underlying processes. The team checked for survival and cell death levels in OSCC cell lines that had been treated with bezafibrate and also measured the key proteins involved in cell death. A biodegradable delivery system was developed by them to improve bezafibrate’s healing effects and control its release mechanisms; which consisted of poly (lactic-co-glycolic acid) (PLGA) as well as polyethylene glycol (PEG). The results showed that bezafibrate reduced OSCC cell survival based on the dose and triggered cell death. It also altered the synthesis of numerous proteins associated with cell death, regulation of the cell cycle, and cellular metabolism thereby enhancing levels of important proteins involved in both intrinsic and extrinsic pathways of cell death like caspases Bcl-2 family members, and PARP. There was better solubility, stability, and cellular uptake when bezafibrate was encapsulated inside PLGA-PEG polymer matrices making apoptosis more pronounced than what was achieved through free drug use alone. These results indicate the potential efficacy of bezafibrate as an anti-cancer agent for oral cancer cells utilizing biodegradable polymers. The proteomic analysis reveals the molecular mechanisms of bezafibrate-induced apoptosis, which suggests that targeted drugs may provide a promising therapeutic strategy for the treatment of oral cancer. Integrating experimental and computational methods suggests the effectiveness of this interdisciplinary approach in advancing cancer research important in drug delivery. This research employed an Artificial Neural Network (ANN) to investigate how parameters behave and interact within a specific project. The neural network method showed robustness against errors in training data and proved effective across different fields, such as speech recognition, image processing, and robotics. Additionally, the network was used to predict cell viability, apoptosis, and protein expression by adjusting the dosages of bezafibrate and polymer matrix.

Alectinib, known as Alecensa, is applied to various health conditions like myelodysplastic syndrome, juvenile myelomonocytic, and myeloid leukemia. Recent research has studied the effect of resonance on the adsorption of Alectinib on fullerene (C60) as a nanocarrier.  For this purpose, Alectinib's adsorption on the fullerene molecule as an adsorbent in both water and gas phases via DFT/B3LYP/6-311+G (d, p) was studied to understand its chemical behavior and calculate the adsorption energy for all active sites. On the other hand, thermodynamic values, such as Gibbs free energy (-89.27 kJ/mol) and Enthalpy (-88.34 kJ/mol) were calculated to show the chemical adsorption for Alectinib drug on fullerene. The assessment of chemical potential value (-3.38 eV), electron affinity (-2.20 eV), ionization energy (8.38 eV), and the other electronic parameters, confirm its thermodynamic stability and indicate the potential role of this drug to adsorb on fullerene. Also, the NBO and ESP analysis were studied to show the effect of resonance on the adsorption of Alectinib where the negative charge was increased on the oxygen of the carbonyl group.

This study examines the bioactive compounds of Artemisia annua (A. annua) and their therapeutic potential in treating Prostate Cancer (PC) through network pharmacology, bioinformatics, and in vitro validation. It screened 126 bioactive principles from the TCMSP database and then reduced them to 22 based on drug-likeness, oral bioavailability, and permeability. The subsequent screening yielded 396 biological targets, with possible duplicates eliminated, and further reduced to 72 putative targets. The comparative analysis with 14,146 PC-related genes resulted in the identification of 62 common targets. Network analysis highlighted three major compounds, Kaempferol, Sitosterol, and Quercetin, which interact with these targets. Molecular docking indicated strong binding affinities of Kaempferol to key hub genes EGFR, MMP9, and GSK3B (Vina scores: -8.4, -9.0, -7.7) that were further supported by stable interactions in molecular dynamics simulations. In vitro studies indicated that the ethanol-DCM extract of A. annua exhibited statistically significant cytotoxic effects on PANC-1 cells. Cell viability assays showed dose- and time-dependent inhibition after 48 hours of treatment. Migration and invasion assays showed a significant reduction in cell movement across transwell membranes at 60 µg/mL (p < 0.01) and 120 µg/mL (p < 0.001). Invasiveness was also significantly suppressed at 60 µg/mL (p < 0.01) and 120 µg/mL (p < 0.001), indicating anti-metastatic potential. Flow cytometric cell cycle analysis showed significant G2/M-phase arrest and 45.6% of cells arrested in G2/M-phase at 120 µg/mL compared to 18.4% in the untreated controls were found (p < 0.001). Annexin V-FITC/PI staining evidenced apoptosis induction, with 28.3% apoptotic cells at 120 µg/mL levels compared to 6.1% in controls (p < 0.001). These findings demonstrate the potential of A. annua to modulate critical molecular pathways in PC, offering promising insights for developing novel therapeutic strategies.

The objective of this study was to utilize network pharmacology and bioinformatics tools to identify and assess bioactive compounds derived from Artemisia vestita for their potential therapeutic use in osteoarthritis (OA). The IMPPAT and KNApSAcK databases were used to identify the bioactive compounds of A. vestita. SwissADME and ProTox 3.0 evaluated the drug-likeness and bioavailability of the material. SwissTargetPrediction was used to identify protein targets. Genes associated with OA were included in the GeneCards database. Compound target and OA-related gene commonalities were found using a Venn diagram. Protein-protein interaction (PPI) networks were constructed using STRING and evaluated using Cytoscape. Hub genes were found with the CytoHubba plugin. CB-DOCK2 was used for molecular docking, while ShinyGO was utilized for enrichment analysis. Root mean square fluctuation was computed using CABS-flex molecular modeling, and docking results were validated with redocking using AutoDock Vina. Molecular dynamics was simulated via the iMODS platform. Out of the 28 bioactive compounds found, eight satisfied the criterion for drug-likeness and bioavailability. 89 target genes are interacting with quercetin. The signalling pathways PI3K-Akt and ErbB were identified by the enrichment analysis. Quercetin has a high binding to OA proteins, including AKT1, EGFR, SRC, MMP9, and IGF1R, according to molecular docking study. Molecular dynamics simulations confirmed the strong interactions and durability of the protein-ligand complexes. An MTT assay was used to validate the DCM/ethanol extract of A. vestita aerial parts against synovial cells (SW-982) and its toxicity on normal cartilage cells (CHON-001). OA cells had significant suppression, whereas normal cells were unaltered. The utilization of network pharmacology and bioinformatics tools in this study has identified quercetin as a highly promising bioactive compound in A. vestita, with potential applications in OA therapy. This research provides a significant understanding of the molecular pathways involved in OA.

Two-dimensional (2-D) materials have emerged as promising candidates for detecting harmful gases due to their high surface-to-volume ratio and fantastic physical characteristics. However, their stability and low reactivity in pure form necessitate surface modifications to enhance interactions with toxic gases. This study introduces a novel Ti-doped G/h-BN/G heterostructure for gas sensing. The h-BN layer, positioned between graphene layers, anchors the Ti atom and enhances sensitivity by inducing quantum tunneling current within the channel. The stability of Ti dopant at different vacancies in the h-BN region, its influence on the electronic structure, as well as the interaction with five distinct toxic gases (NO2, CO, NH3, HCN, H2O), are investigated by employing Density Functional Theory (DFT) and non-equilibrium Green’s function (NEGF) formalisms. Ti doping at B-vacancy (Ti/VB) and Stone-wales defect (Ti/VB+N) sites are found to be highly stable, demonstrating favorable electrical and physical properties for gas detection. The Ti-doped devices show stronger gas adsorption compared to pure devices, leading to enhanced interactions and a greater impact on current flow. Specifically, Ti/VB exhibits higher sensitivity to NO2 and HCN gases, while Ti/VB+N is more suitable for distinguishing CO and NH3 gas molecules. Additionally, interaction with H2O indicates that these structures are capable of operating in humid environments. Therefore, the proposed Ti-doped G/h-BN/G heterostructure is a promising compound for developing accurate and reliable toxic gas detectors.

A sulfamethoxazole (SMX)-molecularly imprinted polymer (MIP) was fabricated by polyphenylenediamine. The composite prepared by the fabricated SMX-MIP and multi-walled carbon nanotubes (OH-functionalized type) was used for modification of a carbon paste electrode. The cyclic voltammetry technique was employed to follow the electrochemical attitude of SMX on the prepared electrode and to determine the optimized conditions for using the sensor in the SMX analysis. Differential pulse voltammetry technique was used to evaluate the figures of merit, selectivity, and application of the developed electrode in SMX determinations. The latter investigations revealed the linearity attitude of the investigated sensor in the range 1.0×10-6–9.0×10-3 mol/L of SMX (with the LOD 4.5×10-7 mol/L and the RSD of 3.45%). The validation of the method was checked by independent HPLC analysis of the assessed real samples.

The acid dissociation constant values of some 2-(3H)-benzoxazolone derivatives were determined in buffered solutions by using the UV-Vis spectrophotometric method. These compounds have benzoxazolone core structures with arylpiperazine substituents and have been investigated for their anti-inflammatory and analgesic activities. The 2-(3H)-benzoxazolone derivatives showed acid dissociation constant values ranging from 8.26 to 9.28. The 5-chloro-2-(3H)-benzoxazolone derivatives exhibit higher acidity than the 2-(3H)-benzoxazolone derivatives. Additionally, a comparison of  5-chloro-2-(3H)-benzoxazolone derivatives showed that derivatives with halogen-containing R2 groups exhibited higher acidity. The findings of this study also suggest that UV–Vis spectrophotometry is one of the most effective techniques for measuring acid dissociation constant values.

Evaluating the relationships between physiological/biochemical traits and yield-related characteristics in medicinal plants under stress conditions is crucial. This study aimed to assess these relationships in lavender genotypes (English and French) under varying drought stress levels (100%, 70±5%, and 40±5% field capacity, respectively) and the effects of different biostimulant applications (individual and combined applications of bacterial inoculants (PGPRs) and Arbuscular Mycorrhizal Fungi (AMFs)). A split-plot factorial test relied on a randomized complete block design during the 2022-2023 growing season. The chlorophyll content peaked at 40.59 µg/g Fresh Weight (F.W.) with dual fertilizer application in French lavender under optimal conditions. Proline content significantly increased under severe drought stress, reaching 823.47 µmol/g F.W. with PGPRs + AMFs application, while it was lowest in non-fertilized conditions. Antioxidant enzyme activities varied with drought stress and fertilization, generally showing higher activities under severe drought stress. Severe stress significantly reduced flower yield, with optimal yields achieved through dual fertilizer application in French lavender (1226.9 kg/ha). The use of PGPRs alone resulted in the highest averages for α-Pinene (3.01%), Camphor (6.36%), Terpinen (7.50%), and Linalyl acetate (24.59%). The combined use of PGPRs and AMFs resulted in the highest averages for Linalool (30.83%) and Caryophyllene oxide (10.22%). Essential oil yields varied: English lavender achieved the best results with standalone PGPRs under non-stress conditions, while combined PGPRs + AMFs were optimal under drought stress. For French lavender, AMFs alone were effective under moderate stress, and PGPRs + AMFs provided the best outcomes under non-stress conditions. Photosynthetic pigments, enzymes, and proline levels influenced flower yield and essential oil content.

The article presents the results of research on the synthesis of new succinimide additives AKI-634, AKI-635, AKI-636, and AKI-637. Additive AKI-634 is a succinimide obtained by condensation of hexene-1 with styrene with maleic anhydride, AKI-635 – of hexene-1 with indene with maleic anhydride, AKI-636 – of hexene-1 with dicyclopentadiene with maleic anhydride and AKI-637 – of hexene-1 with α-methyl styrene with maleic anhydride and further treatment of co-oligoalkenyl succinic anhydrides with diethylenetriamine. The high-performance properties of the additives are confirmed by standard research methods. Studies have shown that additives have high anti-corrosion, detergent, and viscosity-temperature properties. These additives are superior in performance properties to analogs S-5A and IKhP-476. The synthesized succinimides were studied using thermal analysis methods. It was shown that the additives are highly resistant to temperature influences. And so, using the obtained multifunctional succinimide additives, it is possible to develop lubricant compositions of a simpler composition.

Today, the risk of radioactive waste release containing heavy metals into the environment, as well as their penetration into surface and underground water sources, has become a global concern. Hence, it is necessary to investigate the polluting elements distribution in the soil by the disposal site safety assessment studies. One of the important parameters in the radionuclide leakage and migration rate is the distribution coefficient (Kd), which can give more accurate data about the radionuclide migration rate from the site. In this study, the Kd of cesium and uranium radionuclides, the most important elements in radioactive waste repositories, are performed in the Anarak Trench-type near-surface disposal site using batch and column methods. The results of fitting the data with different adsorption isotherm models showed that the Langmuir model has the most agreement with the results. The Kd of cesium was measured in the range of 15 to 47 and 9 to 69 cm3/g for both column and batch methods, respectively. On the other hand, this criterion was estimated at the range of 55 to 80 and 115 to 155 cm3/g for both the same methods and concentrations. Moreover, the comparison of the results shows that the experiments have an appropriate consistency with international standards.

In this research, cloud point extraction was carried out for the removal of Pb2+ ions from aqueous solutions using OC-30, Triton X-100 and Sorbitol as non-ionic surfactants. The effective parameters such as optimum pH, Pb2+ concentration, ligand concentration, surfactant concentration, ionic strength, and the selectivity of the method for Pb2+ions extraction were investigated. The best condition of extraction with maximum efficiency (76%) was determined at pH (4.0-4.5), cation concentration (50mg/L), surfactant concentration (0.01mol/L), and ligand concentration (0.001mol/L). The results of the SEM images emphasized the presence of Pb2+ ions in the surfactant aqueous solution. According to the chain length and molecular weight, the best conditions for removing Pb2+ ions were recorded as OC-30˃ Triton X-100˃ Sorbitol.

Water contamination by Methylene Blue (MB) is a significant environmental challenge that requires cost-effective purification strategies. The green algae Coelastrella was used as an adsorbent inside the airlift bioreactor as an effective and inexpensive material. Experiments were conducted over a range of conditions, including initial MB concentration (3-30 mg/L), contact time (0-60 min), air flow rate (200-300 mL/min), algae dosage (0.1-2 g/L), and temperature (20-40 ˚C). Diverse characterization techniques were employed to comprehensively understand the process and its outcomes. These techniques include Energy Dispersive Spectroscopy (EDS), Fourier Transform-InfraRed (FT-IR) spectroscopy, UV-Visible (UV-Vis) spectrophotometry, and Scanning Electron Microscopy (SEM). Adsorption isotherms were analyzed in this study, with a focus on the Langmuir, Freundlich, and Temkin models. The Langmuir model had the highest (R² = 0.9998), indicating monolayer adsorption with a maximum adsorption capacity of 30 mg/g. Additionally, kinetic studies found the pseudo-second-order model to be the most accurate (R² = 0.9990). Under optimal conditions, the process achieved a high removal efficiency of 98.9%. Finally, mass transfer adsorption models were examined using three models. When these models were compared, the Liquid film diffusion model had the highest value (R² = 0.9736). These results suggest that algae biomass is an effective, green adsorbent for MB removal, presenting a viable alternative to conventional treatments..

There is an increasing demand for mass graphene production via a simple, environmentally friendly, and cost-effective method. In this study, a versatile method was developed to prepare high-quality mono/bilayer graphene using magnetic water. Graphene nanosheets were synthesized through this method and then were characterized. A Molecular Dynamics (MD) simulation was also performed to determine the effect of magnetic water on graphite exfoliation. Magnetic water was created in the laboratory by flowing water between two 7000-gauss magnets for periods of two to six hours. The durability of magnetic water was studied using a Magnetometer-Based Diagnostic Test. Then, generated magnetic water was added to the graphite. By adding magnetic water, the graphite absorbed more energy, creating more space among graphite layers by weakening and breaking van der Waals bonds and forming high-quality graphene. Finally, mono/bilayer graphene formation was confirmed via RAMAN, X-Ray Diffraction (XRD), and Atomic Force Microscopy (AFM) tests. Based on the results, using magnetic water increased graphene yield to almost 67%, while simulation studies predicted a yield of 70%. In addition, MD simulations indicated that 35 graphene nanosheets were separated, with a total of 1252 carbon atoms among them. The results of this investigation indicate that the graphene nanosheets can be effectively produced using magnetic water.

Among the various methods employed to purify Industrial Phosphoric Acid (IPA), the adsorption method has received considerable attention in both research and industrial settings. In this study, for the first time, carbon black was used as an adsorbent for the discoloration and removal of interfering iron and magnesium ions from Industrial Phosphoric Acid (IPA) at a 54% concentration, and its performance was compared with various common adsorbents. The carbon black adsorbent achieved a 27.81% removal of iron cations, a 38.72% removal of magnesium cations, and a complete removal of color from the IPA. A univariate algorithm was employed to examine the impact of operating conditions, such as the acid-to-adsorbent ratio (11 to 80), contact time (30 to 540 minutes), initial concentrations of iron cations (7310 to 460 ppm), and magnesium cations (11950 to 750 ppm), temperature (25 to 65 °C), and stirring rate (100 to 1000 rpm). Optimal results were achieved at a stirring rate of 500 rpm, a contact time of 300 minutes, a temperature of 25 °C, initial concentrations of iron cations 460 ppm and initial concentrations of magnesium cations 750 ppm, and an acid-to-adsorbent ratio of 16, resulting in the removal of 39.13% of iron and 48% of magnesium. Adsorption kinetics, isotherms, and thermodynamics were investigated. The findings indicate a stronger alignment with the pseudo-second-order kinetic model for the system. For iron cations, the strongest correlation is observed with the Temkin isotherm model, while for magnesium cations,  it corresponds more closely with the Dubinin-Radushkevich isotherm model. The thermodynamic analysis reveals that the adsorption process for iron cations is endothermic and spontaneous, demonstrating an increase in disorder following surface adsorption. In contrast, the adsorption process for magnesium cations is exothermic and non-spontaneous, leading to a decrease in system disorder.

In this research, zinc oxide (ZnO) nanoparticles were synthesized and investigated as adsorbents for the removal of vapors of toluene from air samples. The synthesized adsorbent was characterized by using X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). Adsorption efficiency was measured using Gas Chromatography (GC). A Plackett-Burman design (PBD) was employed to identify the significant factors affecting the adsorption process, including the temperature of the solution, adsorbent dosage, and initial concentration, Optimization of important parameters was performed using Response Surface Methodology (RSM), which achieved a maximum toluene removal efficiency of 93.98% which represented good agreement with experimental results of 93.1%. The highest adsorption efficiency for toluene was obtained at 75.5 ˚C with its initial concentration of 247 mg/ L and ZnO adsorbent dosage of 9.73 mg. Adsorption kinetics and isotherm studies revealed that the process follows a Langmuir isotherm that indicated monolayer adsorption and a pseudo-second-order with chemical interaction. The study concludes that porous ZnO nanoparticles are highly effective for toluene removal from air, providing a cost-efficient and scalable solution for air purification in industrial and environmental applications.

Transfer hydrogenation of naphthalene is a safe and effective method to produce tetralin. Partial transfer hydrogenation of naphthalene was performed at a constant pressure of 7 bar in the presence of 2-propanol (as hydrogen donor) and the Raney nickel catalyst. Raney nickel to naphthalene mole ratio, 2-propanol to naphthalene stoichiometry ratio or Φ, and time were the main and effective parameters. Response surface methodology was used to optimize the parameters. A quadratic correlation was proposed for the tetralin conversion is 0.3 to 0.7 for Raney nickel to naphthalene mole ratio, 3 to 6  for Φ, and 0.5 to 3 hours for reaction time. The optimum values for Raney nickel to naphthalene mole ratio, Φ, and time were 0.6, 4.5, and 1.75 h, respectively. Under these conditions, the conversion value was obtained as 99.6 % which was satisfied with experimental data. Results showed that the Raney nickel to naphthalene mole ratio had the most effect on the conversion whereas Φ had the least effect.

The fluid catalytic cracking unit converts heavy feedstocks into more valuable gasoline and oil products, representing an essential component in refineries. The variables, including gas oil supply temperature (Tf), gas oil supply flow rate (Ff), and air temperature (Ta), are controlled and manipulated by this unit, which poses a significant challenge due to its complex interactions. To address these complexities, this study investigates the control of riser and regenerator temperatures (TR, TG) in an industrial Universal Oil Products (UOP) fluid catalytic cracking unit using proportional-integral and fuzzy logic controllers. The fuzzy logic controller, with five fuzzy sets generating 25 rules, is implemented through MATLAB simulation. The simulation program is formulated based on the principles of mass and energy balance of the unit. The performance of the controllers, including PI and fuzzy logic controllers, is evaluated and compared by introducing disturbances in the gas oil supply temperature, gas oil supply flow rate, and air temperature. The results show that the fuzzy logic controller outperforms the PI controller, exhibiting a lower integral absolute error. Compared to the PI controller, the fuzzy logic controller demonstrates improved performance, characterized by stable responses and shorter settling times. These findings highlight the effectiveness of the fuzzy logic controller in achieving better control performance for Fluid Catalytic Cracking Units (FCCU).

Taylor bubbles are commonly utilized in a wide range of industrial applications involving non-Newtonian fluids, and a thorough understanding of the relevant knowledge is helpful to the design optimization of related industrial processes. This study investigated the behavior of Taylor bubbles in shear-thinning fluid using OpenFOAM. The numerical method is verified by comparing the results with experimental data, additionally, the effects of flow index n, surface tension σ, and zero shear rate viscosity μ0 on the motion behavior of Taylor bubbles were investigated. The results show that as the flow index n and zero shear viscosity μ0 increase, the terminal velocity of the Taylor bubbles decreases. The impact of various operating parameters on the bubble nose's form is insignificant. Regarding the liquid film surrounding the bubble, when n is small, the bubble rear is broken seriously, resulting in a shorter bubble and thinner liquid film. As the flow index n increases, the bubble elongates, and the liquid film becomes thicker, the length of the wake behind the Taylor bubble decreases. The surface tension mainly affects the bubble rear but has little impact on the bubble nose and rising velocity. For high μ0, the bubble rear does not break, and the shear thinning area is small.

Liquid-liquid axial hydrocyclones (LLAHC) are broadly employed in various industries to remove oil from water due to their low maintenance costs, simple structure, and high efficiency. This paper proposes a novel LLAHC with guide vanes and examines its performance numerically using the mixture two-phase scheme and Reynolds stress model (RSM). The results demonstrate that the new design significantly improves efficiency and reduces pressure drop. Examining the effect of various parameters reveals that some parameters, such as inlet velocity and guide vane cross-sectional profile, have a great effect, and some, including vortex finder length, have a low influence on LLAHC performance. The findings reveal that when the guide vanes with airfoil # 1 are used, the suggested LLAHC performs best at an inlet velocity of 2.8 m/s, an oil exit diameter of 25 mm, and a vortex finder length of 10 mm.

This research explores the use of energy storage systems in combination with PCM to enhance air conditioner (AC) efficiency by lowering inlet air temperature. The study examines various PCM configurations and materials, including paraffin and salt-based PCM, and evaluates the impact of airflow speed on cooling performance. Both experimental and simulation methods were employed, replicating hot-season conditions in Iran. Simulations conducted with ANSYS/Fluent modeled four duct designs, containing one to four PCM enclosure series, subjected to air velocities between 2 m/s and 6 m/s. Results showed that using four PCM series (Design 4) achieved a significant temperature reduction, lowering temperature to 34.5 °C—a drop of 12.8 °C. Salt PCM outperformed paraffin in cooling efficiency. The experimental setup, incorporating PCM enclosures, was tested over three days, with paraffin (RT-31) achieving a maximum temperature drop of 3 °C and a net heat reduction of approximately 16%. These findings demonstrate the potential of PCMs, particularly salt hydrate, to improve AC pre-cooling efficiency.

The ventilation system in tunnels serves dual roles, providing fresh air for comfort in normal conditions and managing smoke during emergencies. It maintains air quality for a safe environment in routine operations, safeguarding occupants. In emergencies, it crucially aids in smoke control, ensuring safety for rescue efforts and limiting fire spread. Regular tests are essential to validate safety systems, a prerequisite for tunnel usage approval. These tests typically involve fire and smoke assessments, verifying control and evacuation systems. Compliance ensures system efficacy, public safety, and risk mitigation through continuous improvement, enhancing overall tunnel safety and reliability. The current study experimentally analyzed the performance and behavior of the longitudinal ventilation system and related sub-systems in hot smoke control and toxic gas management through a standard fire test. Based on the test results and experimental data, a suitable numerical simulation model was developed to predict the behavior of the ventilation system in larger fires as well. The numerical and experimental results of this study indicate that a properly functioning ventilation system can lead to the creation of a safe and smoke-free environment on both sides of a fire. This effect is more noticeable in small fires where the fire's heat release rate is low and the tunnel cross-section is relatively large. In such scenarios, smoke tends to gather at higher levels during the initial stages of the fire, with only a small amount descending to lower levels. However, in cases of high-intensity fires, the situation changes significantly, and smoke settles, particularly downstream, on the tunnel floor after a certain period of time. The presence or absence of traffic was also observed to affect the quality of smoke dispersion and propagation. Additionally, the findings of this study can assist emergency fire response teams in managing safety within tunnels under diverse circumstances.

This study assesses the feasibility of using high-sulfur residuals from Tawke and Shikhan crude oils as a fuel source for heavy industries. The primary aim was to evaluate its industrial applicability and environmental implications. Petroleum coke, a byproduct obtained via atmospheric and vacuum distillation, was characterized by its high sulfur content, with values ranging from 3.4% for Tawke to 12.5% for Shikhan. Quantitative results from fractional distillation revealed a higher cumulative distillate percentage for Shikhan crude compared to Tawke, with sulfur mass fractions reaching up to 1.1% for the 290°C distillate fraction in Shikhan oil. Despite its potential as a cost-efficient fuel, high-sulfur petroleum coke presents environmental challenges, particularly due to sulfur dioxide emissions, which could lead to air pollution and acid rain. The findings emphasize that proper emission control technologies and stringent regulatory standards are necessary to mitigate these risks. The study further highlights that the high carbon content and calorific value of this coke make it a viable energy source, but environmental trade-offs must be considered. The novelty of this research lies in its detailed analysis of high-sulfur petroleum coke derived from specific Iraqi crude oils, providing valuable insights for industrial applications in sulfur-rich crude-producing regions. The study contributes to the ongoing discussion about alternative fuels in heavy industries, especially in regions reliant on high-sulfur crude oil reserves.

In this study, the erosion rate of an elbow in a natural gas pipeline in the dense phase, pseudo-dense phase, and vapor phase were analyzed through a combination of computational fluid dynamics and the discrete element approach. The erosion rate of the natural gas pipeline in the three phases was evaluated at different particle mass flow rates, Reynolds numbers, particle diameters, and curvature radii. Results showed that the erosion rate for all three phases increased with Reynolds number, particle diameter, and particle mass flow rate while decreasing as the curvature radius increased. The maximum erosion rate (MER) at a Reynolds number of 1,000,000 in the dense phase was 80% and 23% lower than the vapor phase and pseudo-dense phase, respectively. At a Reynolds number of 10,000,000, the MER in the dense phase was 59% and 16% lower than the vapor phase and pseudo-dense phase, respectively. At different particle mass flow rates and particle diameters with a constant Reynolds number for natural gas flow, the MER in the dense phase was almost 63% and 20% lower than the vapor phase and pseudo-dense phase, respectively. The Reynolds number had a more significant effect on the erosion rate compared to particle mass flow rate, particle diameter, and curvature radius. Additionally, as the curvature radius increased, the reduction in erosion rates in the dense and pseudo-dense phases was greater than in the vapor phase.

Fruit snacks are considered traditional products with high nutritional value, especially for children. The purpose of the present research is to manufacture snacks as functional fermented components using Bacillus coagulans, which brings health improvement of probiotic products to consumers and beneficial consumption. In the present study, mango and kiwi wastes and also mixed composition were produced as control and fermented leathers, which several tests such as pH, acidity, color, vitamin C, antioxidant, probiotic bacteria viability, digestive tract simulation, antimicrobial, texture, Fourier Transform InfraRed (FT-IR) spectroscopy, Scanning Electron Microscopy (SEM) and sensory performed during the 42 days. The assay results illustrated that fermentation elevated acidity, vitamin C, antioxidant, and antimicrobial function for leathers; however, not indicate a significant effect on texture and color, which illustrated a small negative impact on odor. All samples received an acceptable sensory, and kiwi leather had the highest acidity (1.45 g citric acid / 100 g leather), vitamin C (80.51 mg/100 g), antioxidant (99.5 %), and hardness (11.89 N) compared to others. The kiwi and mixed leathers had the maximum hardness (11.89 N), cohesiveness (0.85), and adhesiveness (0.75 mJ), respectively. Overall probiotic viability in treatments was further than 106 CFU/g on the 42nd day. Based on simulation assay for a digestive system in enteric I, II, and gastric phases, probiotic survival of mango leather (8.30×106 CFU/mL) was higher than others. FT-IR and SEM provided chemical compositions, homogeneous dispersion, and uniform structures, respectively. According to the results, probiotic leather demonstrated the main potential to apply as a functional snack.