Takestan Islamic Azad University

Afjaei M.A., Kakavand F., Seidi H., Taherkhani A.

Barikbin M.S.

This article introduces a numerical approach employing the local Radial Basis Function Partition of Unity (RBF-PU) method to solve the generalized two-dimensional coupled Klein–Gordon–Zakharov (KGZ) system, describing the interaction between electromagnetic waves and charged particles in plasmas. The method utilizes the matrix representation of spatial operators to transform the system into time-dependent differential equations, solved using second-order finite difference schemes. The RBF-PU method, based on scaled Lagrangian polyharmonic splines, ensures stability and robust numerical solutions. Numerical simulations validate the effectiveness of the proposed method for solving the coupled KGZ systems.

Pakyari H.

Abstract Insects' development can be significantly impacted by various environmental factors, including temperature. Thus, this study aimed to investigate the effect of temperature on the predatory thrips, Scolothrips longicornis Priesner (Thysanoptera: Thripidae), which feeds on the strawberry spider mite, Tetranychus turkestani Ugarov and Nikolski (Trombidiformes: Tetranychidae). Under laboratory conditions (16:8 L:D, 75 ± 5% RH), the impact of various temperature regimens (15–37.5°C) on the development, population parameters, and mass production of S. longicornis was assessed. Additionally, an age-stage, two-sex life table of the species was constructed. The study revealed that S. longicornis' pre-adult developmental period decreased as temperature increased until 35°C, after which the developmental period increased. The longevity of both males and females displayed significant differences across the temperature range, with the longest lifespan observed at 15°C and the shortest at 37.5°C. At 26°C, the mean total fecundity of S. longicornis was significantly higher (53.52 eggs per female) than the fecundity observed at other temperature regimens. The intrinsic rate of increase (r) and finite rate of increase (λ) demonstrated the highest values at 35°C. While R0 increased as the temperature rose from 15 to 30°C, it rapidly decreased at 35 and 37.5°C. The findings of this study suggest that temperature plays a crucial role in enhancing the rate of development and reproduction of S. longicornis, and a temperature range of 26–30°C could be considered optimal for rearing and mass production of S. longicornis.

Sharhan Z.S., Cucuzza R., Domaneschi M., Ghodousian O., Movahedi Rad M.

Carbon-fiber-reinforced polymer (CFRP) laminates have gained attention for their potential to reduce carbon emissions in construction. The impact of carbon-fiber-reinforced polymer (CFRP Laminate) on carbon emissions and the influence of elasto-plastic analysis on this technique were studied in this research. This study focuses on how CFRP can affect the environmental footprint of reinforced concrete structures and how elasto-plastic analysis contributes to optimizing this strengthening method. Four flat RC slabs were created to evaluate this technique in strengthening. One slab was used as a reference without strengthening, while the other three were externally strengthened with CFRP. The slabs, which were identical in terms of their overall (length, width, and thickness) as well as their flexural steel reinforcement, were subjected to concentrated patch load until they failed. The strength of two-way RC slabs was analyzed using a concrete plastic damage constitutive model (CDP). Additionally, CFRP strips were applied to the tension surface of existing RC slabs to improve their strength. The load–deflection curves obtained from the simulations closely match the experimental data, demonstrating the validity and accuracy of the model. Strengthening concrete slabs with CFRP sheets reduced central deflection by 17.68% and crack width by 40%, while increasing the cracking load by 97.73% and the ultimate load capacity by 134.02%. However, it also led to a 15.47% increase in CO2 emissions. Also, the numerical results show that increasing the strengthening ratio significantly impacts shear strength and damage percentage.

Habashneh M., Ghodousian O., Fathnejat H., Movahedi Rad M.

In this manuscript, a novel approach to topology optimization is proposed which integrates considerations of uncertain load positions, thereby enhancing the reliability-based design within the context of structural engineering. Extending the conventional framework to encompass imperfect geometrically nonlinear analyses, this research discovers the intricate interplay between nonlinearity and uncertainty, shedding light on their combined effects on probabilistic analysis. A key innovation lies in treating load position as a stochastic variable, augmenting the existing parameters, such as volume fraction, material properties, and geometric imperfections, to capture the full spectrum of variability inherent in real-world conditions. To address these uncertainties, normal distributions are adopted for all relevant parameters, leveraging their computational efficacy, simplicity, and ease of implementation, which are particularly crucial in the context of complex optimization algorithms and extensive analyses. The proposed methodology undergoes rigorous validation against benchmark problems, ensuring its efficacy and reliability. Through a series of structural examples, including U-shaped plates, 3D L-shaped beams, and steel I-beams, the implications of considering imperfect geometrically nonlinear analyses within the framework of reliability-based topology optimization are explored, with a specific focus on the probabilistic aspect of load position uncertainty. The findings highlight the significant influence of probabilistic design methodologies on topology optimization, with the defined constraints serving as crucial conditions that govern the optimal topologies and their corresponding stress distributions.

Ajoudani M.R., Sayfzadeh S., Valadabadi S.A., Shahsavari N., Zakerin H.

AbstractTo explore the effects of varied irrigation regimes on different sorghum [Sorghum bicolor (L.) Moench] cultivars, a split‐plot experiment adhering to a randomized complete block design with three replications was conducted in 2016 across the Khaveh and Varamin regions. The experimental treatments encompassed irrigation levels as the primary factor and four different sorghum cultivars as the secondary factor. Cultivars exhibiting larger leaf areas were associated with higher chlorophyll content, which enhanced biomass production and the quality of sorghum products. Notable variability in leaf area and crude fiber content was observed across irrigation regimes and cultivars, with 2121 cm2 to 7153 cm2 and 40.4% to 50.7%, respectively. Plant height, total dry weight, and water use efficiency were markedly higher under well‐irrigated conditions than those under moderate and severe water deficit conditions. Specifically, the Pegah cultivar displayed the highest leaf area in the Varamin region, measuring 4612 cm2 and 5911 cm2, whereas the Thin Stem cultivar exhibited the lowest leaf area at both locations. Our findings suggest that the Pegah cultivar maintained a high leaf area without reducing total dry weight, indicating its stability across different environments. Therefore, to produce sorghums in similar climatic conditions, full irrigation is recommended. These results underscore the significance of ongoing research and breeding initiatives to leverage genetic diversity and improve sorghum cultivars.

Pakyari H., Zemek R.

Understanding the lethal and sublethal impacts of pesticides on biocontrol agents is crucial for the successful implementation of integrated pest management (IPM) programs. This study investigated the sublethal effects of fenpyroximate, a broad-spectrum acaricide/insecticide, on the fitness of Scolothrips longicornis Priesner (Thysanoptera: Thripidae), a key predator of the two-spotted spider mite, in controlled laboratory environments. Adult predators were exposed to pesticide residues on leaf discs to estimate parameters of concentration-mortality response models for females and males and calculate median lethal concentration (LC50) as well as sublethal concentrations (LC10, LC20 and LC30) used in subsequent bioassays. The estimated LC50 values for female and male predators were 18.32 and 15.49 µg a.i./mL, respectively. Results of sublethal concentrations experiments did not reveal any significant impact on the development of each stage or the survival rate of S. longicornis juveniles compared to those in the control group. However, the longevity of adult males and females was significantly lower at all sublethal concentrations than in the control. Moreover, the fecundity decreased significantly at all sublethal concentration treatments. With one exception (LC10), both the adult preoviposition period and total preoviposition period increased with increasing sublethal concentrations compared to those of the control. The shortest oviposition period (9.30 days) was observed at the LC30. For the life table parameters of S. longicornis females treated with sublethal concentrations, a significant decrease was found in the intrinsic rate of increase, net reproductive rate and finite rate of increase, whereas the mean generation time in the LC10 treatment was lower than that in the other treatments. This underscores the imperative need to consider sublethal concentration effects of fenpyroximate in the strategic design and implementation of IPM systems.

Shafaie V., Ghodousian O., Ghodousian A., Gorji M., Mehdikhani H., Movahedi Rad M.

This study investigates the shear bond strength between four widely used façade stones—travertine, granite, marble, and crystalline marble—and concrete substrates, with a particular focus on the role of polypropylene fibers in adhesive mortars. The research evaluates the effects of curing duration, fiber dosage, and mechanical anchorage on bond strength. Results demonstrate that Z-type anchorage provided the highest bond strength, followed by butterfly-type and wire tie systems. Extended curing had a significant impact on bond strength for specimens without anchorage, particularly for travertine. The incorporation of polypropylene fibers at 0.2% volume in adhesive mortar yielded the strongest bond, although lower and higher dosages also positively impacted the bonding. Furthermore, the study introduces a novel fuzzy logic model using the Dombi family of t-norms, which outperformed linear regression in predicting bond strength, achieving an R2 of up to 0.9584. This research emphasizes the importance of optimizing fiber dosage in adhesive mortars. It proposes an advanced predictive model that could enhance the design and safety of stone-clad façades, offering valuable insights for future applications in construction materials.

Shahidi F., Shahidi F., Ghodousian O., Shafaie V., Movahedi Rad M.

Earthquakes, among the most destructive natural hazards, result in substantial economic and demographic losses. An effective strategy to mitigate future structural damage involves investigating past collapses. Numerical modeling proves instrumental in analyzing and identifying deficiencies in collapsed structures. This study numerically evaluates a steel silo damaged during the 2011 Van earthquake. Employing non-linear time history and pushover analyses, the research assesses the silo’s performance. Findings highlight inadequate welding dimensions and incomplete fusion with the base metal in fillet welds between columns and the silo tank as primary causes of collapse. Numerical simulations with varied column removal scenarios underscore the importance of robust silo tank-column connections in reducing earthquake-induced damage.

Gosztola D., Cucuzza R., Szép J., Domaneschi M., Ghodousian O., Movahedi Rad M.

This research employs plastic limit analysis to examine load combinations, contact interactions, and friction effects on steel–concrete connections. A nonlinear finite element model was developed using ABAQUS 2021, incorporating the concrete damage plasticity model and contact friction interactions. The model’s validity was confirmed through laboratory experiments. Results indicate that contact elements and friction between the top flange, concrete slab, and studs significantly influence structural behavior. Unlike conventional push-out tests, real deck–slab connections exhibit different load-displacement responses due to the self-weight and additional loads, such as vehicular traffic. Under horizontal loading, extensive failures with large deformations along the studs occur, while vertically compressive loads lead to failures around the connections.

Afjaei M.A., Amirabadi H., Sarafraz M., Afshari H.

This paper studies the dynamics of a rotating circular cylindrical shell with non-uniform thickness. The base material of the shell is a polymer which is strengthened with either carbon nanotubes (CNTs), graphene nanoplatelets (GNPs), or graphene oxide powders (GOPs) which are distributed functionally graded (FG) with volume fractions that change in the axial direction. The first-order shear deformation theory (FSDT) is utilized to conduct the mathematical modeling of the shell and the Coriolis, centrifugal, and relative accelerations, and the initial circumferential tension are incorporated. The governing equations are attained via Hamilton’s principle and are solved through a semi-analytical solution. The dependency of the natural frequencies and critical angular velocity on several factors are discussed. It is discovered that by considering the same mass fractions for CNTs, GNPs, and GOPs, the GNPs bring about the best reinforcing effect and the CNTs have the weakest reinforcing effect.

Rahmani N., Ebrahimi R.

Pollutants are removed from the environment in a short time when water or biological fluids contain certain substances enter the hydrogel. In this research, we synthesized four kinds of acrylic hydrogels (performance about 50%) and applied for the kinetic sorption study of methylene blue (MB) from aqueous solutions. The adsorption of MB on the developed adsorbents (containing Fe3O4, ZnSe, and starch) was examined in a batch system. Characterization of the prepared acrylic adsorbents was performed by UV, FT-IR, SEM and XRD analyzes. The results showed that the four hydrogels could efficiently remove MB from solutions. The residual concentration of MB was analyzed by UV–Vis spectrophotometry at 662 nm (λmax). First the calibration curve of methylene blue dyes was obtained. Then the UV spectrum was taken from the mixture of gel and methylene blue at different concentrations (78,125, 13,950 and 19,531 ppm) and different time intervals (0–10 min) and the graph of the adsorption changes was obtained for each one. These graphs showed the kinetics of adsorption and showed this fact that the adsorption process has followed the Langmuir isotherm (the adsorption values qmax of 42 mg.g−1), and in some cases the Freundlich model. Among the kinetic models applied, the pseudo-second-order (k about 0.3 M−1.min−1) kinetic model was identified with the highest regression coefficients (the first in the high concentrations and the second in the low concentrations). A proposed adsorption mechanism to acrylic hydrogel was illustrated based on the chemical structure of MB and related hydrogel. The stability and reusability of hydrogels and the recovery of absorbed pollutants are among the advantages of this method which shows its economic efficiency.

Shahbazinasab M.K., Rahimpour M.R., Setoodeh P., Peyrovedin H., Kargari N.

In today's industrial landscape, energy management, process modification, and reduction of atmospheric concentrations of pollutants and safety risks have become paramount. This focus is driven by the need to address environmental concerns, economic efficiency, and the global energy and climate change crisis. In gas refineries, incinerators are widely used to convert deadly and environmentally polluting acid gases into less hazardous gases. Therefore, improving incinerator performance can significantly impact environmental, economic, and energy aspects. According to the results of an energy management study at the domestic gas processing plant, the acid gas incineration unit was identified as a significant energy use. Therefore, based on the effects of the performance of this incinerator from environmental and energy points of view, the mentioned unit was prioritized for modification in this work. For this purpose, incinerator performance was assessed using Promax simulation, and Hazard and Operability (HAZOP) analysis was employed to identify potential hazards. The simulations revealed that acid gas residence time was 0.81s, longer than the 0.6s initial design with the damper in place. This suggests damper removal is feasible. Removing the damper reduces residence time and lowers incinerator temperature, especially during startup. Therefore, temperature was considered as the keyword in the HAZOP study, and a number of recommendations were proposed to eliminate or mitigate the risks of system modification. Furthermore, the assistance of results obtained from energy management based on ISO 50001:2018 standards confirm improvements in energy efficiency and fuel consumption, which have positive economic and environmental impacts. Moreover, the study employs a Life Cycle Assessment (LCA) approach using SimaPro Software 9.5.0.1 and the CML-baseline method (Centrum voor Milieukunde Leiden) for environmental impact assessment. The results reveal that, across ten environmental impact categories, the modified project exhibits significantly reduced environmental impacts compared to its original state.

Rahmani Y., Gholami Parashkoohi M., Afshari H., Mohammadi A.

The critical necessity of decreasing energy consumption and environmental effects is vital in various facets of urban life, particularly in urban waste management. This research aimed to evaluate the energy flow, CExD, and Life Cycle of a composting system for Municipal Solid Waste (MSW) in Tehran province, Iran. The initial phase entailed assessing the energy flow and effectiveness of the composting system, while the subsequent phase focused on enhancing energy efficiency through the application of Data Envelopment Analysis (DEA) to determine an optimal energy consumption strategy for conserving energy and reducing environmental impacts in Tehran's MSW composting system. Over a 90-day period, the analysis of energy usage revealed an energy input and output of 417.30 GJ (8500 t MSW)−1, with 227.02 GJ (8500 t MSW)−1 linked to transportation and 190.28 GJ (8500 t MSW)−1 related to composting activities. The overall energy consumption in the composting system was determined to be 6424.77 GJ (8500 t MSW)−1. By applying DEA optimization, energy savings of 14.45 GJ (8500 t MSW)−1 were accomplished in the composting process, with a significant reduction in electricity usage contributing to these savings. The environmental impact of the energy consumption patterns identified by DEA was notably lower compared to current energy practices. The most notable decrease in impact was observed in the Photochemical Oxidation category. By following the energy usage pattern recommended by DEA, the Global Warming Potential impact reduced by 500 kg CO2 eq. per 8500 t MSW. Additionally, the optimization of energy use through DEA led to a decrease in fossil energy resource depletion by around 4 GJ (8500 t MSW)−1 in the composting process.

Azadeh S., Parashkoohi M.G., Zamani D.M., Firouzi S.

Sugarcane bagasse, a by-product of sugar production, has potential as a feed ingredient for animals. This study examines the environmental impact and energy use efficiency of using sugarcane bagasse for animal feed. The research indicates that the total energy consumption for producing fodder is 30,329.94 MJ ton−1, with input energy exceeding output energy. Sugarcane bagasse accounts for over 50% of energy consumption, along with significant contributions from electricity and natural gas. Energy efficiency and intensity are calculated at 0.03 kg MJ−1 and 30.32 MJ kg−1, respectively, suggesting a high energy requirement per kg of feed. The net energy is calculated at -5329.94 MJ ton−1, highlighting inefficiencies in energy use. The study shows a measurable impact on human health (0.30 DALY) but a relatively minor impact on ecosystem quality (0.0005 species.yr). The high energy consumption of 93,602.34 MJ ton−1 indicates a heavy reliance on non-renewable fuel sources, specifically fossil fuels. These findings underscore the importance of improving energy efficiency and resource utilization in feed production processes.