Imam Khomeini International University

This work presents a small four-port multiple-input multiple-output (MIMO) antenna for Ultra Wideband (UWB) applications. Four monopole radiating components make up the suggested antenna. Every monopole is positioned perpendicularly to the components that surround it. This compact antenna, 40 mm × 40 mm, is printed on a single layer substrate (FR4) with a thickness of 1.6 mm and an εr = 4.4. This antenna features an isolation of less than −14 dB and an impedance bandwidth (S11 < −10 dB) of 2.57–12.20 GHz. The average gain is 4.7 dBi and the envelope correction coefficient (ECC) is less than 0.15. The suggested antenna is a good option for UWB applications because of its Ultra Wide bandwidth and small footprint.

The International Maritime Organization (IMO) has implemented new sulfur content regulations for marine fuels in response to growing environmental concerns, including global warming. These regulations severely and costly restrict refinery operations. Oxidative desulfurization (ODS) is an attractive desulfurization method that has advantages such as mild operating conditions and a hydrogen-free process over traditional processes such as hydrodesulfurization (HDS). One can employ oxidative desulfurization in addition to or instead of hydrodesulfurization. Organic sulfur molecules undergo oxidative desulfurization, which results in the formation of polar sulfones. The refined fuel oil is then separated from the oxidized sulfones using methods such liquid-liquid extraction, distillation, and absorption. This work examines and simulates the process of separating sulfur-containing oxidized chemicals from fuel oil utilizing oxidative desulfurization technology. Acetic acid served as the catalyst and hydrogen peroxide as the chosen oxidant. This effort involved simulating the oxidative desulfurization of fuel oil and then using absorption methods to separate the oxidized sulfones. Subsequent procedures including absorption and distillation were used to separate and recover the resultant effluent, solvent, and oxidant from the remaining components. According to the simulation results, the procedure was run at 80 °C and a modest pressure of less than 5 bar. Sulfur content in the original hydrocarbon fuel was 3.5% by weight; at the output, it was less than 0.5% by weight. The findings of the sensitivity analysis of a few key factors demonstrated that the conversion percentage increased from 84 to 98% when the reactor’s diameter was changed from 0.5 to 1.2 m and its length was extended to the desired amount. The reaction conversion percentage has increased significantly when the mass flow rate of hydrogen peroxide is increased from 0.5 to 1.5 kg/h, the pressure is increased from 1.5 to 5 bar, and the temperature is raised to 30 °C. According to the process optimization data, the ideal state had an exergy efficiency of 55.57%, a solvent waste rate of 1.75%, and a sulfur content of 0.22% in the fuel.

Purpose The present study explores the synergistic impact of tDCS and low-intensity exercise with practical blood flow restriction on the thickness, strength, and electrical activity of the biceps brachii muscle. Methods The study involved 44 healthy young men, divided into four groups: tDCS-pBFR (n = 11), Sham-pBFR (sham-tDCS) (n = 9), tDCS (n = 10), and control (n = 8). Six participants were unable to complete the exercises. Anodal tDCS was applied over the M1 with an intensity of 1.5 (mA). The participants executed dumbbell curls for the biceps at 80% of their 1RM. Following initial assessments, a covariance analysis was performed. The researchers measured biceps muscle strength, volume, and electromyography activity. Results The results found that the increase in arm muscle circumference was significant in the groups that performed pBFR exercises (p < 0.05), regardless of whether tDCS was applied or not. We observed no significant difference in strength and electromyography between the tDCS-pBFR and Sham-pBFR groups. Conclusions The present study provides experimental evidence of the lack of synergistic effects of using tDCS in combination with low-intensity exercises with practical blood flow restriction after 4 weeks of training.

Concrete’s widespread use in construction is increasing due to urbanization and population growth. While it offers durability and strength, its production poses environmental challenges. Researchers and global initiatives are working towards more sustainable concrete production methods and effective waste management, particularly for paper waste (WPA) and polyethylene terephthalate waste (PET). This study aims to investigate the effects of waste paper aggregate (WPA) on the flow time, compressive strength, flexural strength, and thermal conductivity of mortars. Furthermore, it explores the potential of polyethylene terephthalate (PET) to enhance the compressive and flexural strengths of these mortars. To conduct this study, the materials were characterized using EDX spectroscopy and SEM analysis. Gwyddion software was employed to conduct a comprehensive analysis of the grain segmentation and microstructural characteristics of the WPA mortars. Subsequently, four distinct mixtures were selected for further investigation. The first mixture involved substituting sand with various percentages of waste paper aggregate (WPA) (1–4%) without PET. The second mixture included WPA (1–4%) and 5% PET. Due to the ineffective plasticizer in the first two mixtures, the third mixture replaced 20% of quarry sand with dune sand (DS) while maintaining the same percentages of WPA and PET as in the previous mixtures. The results indicate that mortars RM1 (0% WPA + 0% PET) and RM2 (0% WPA + 0% PET + 20% DS) demonstrated the best flow time. This suggests that incorporating WPA and PET into the mortar mix can negatively impact its workability, making it more challenging to handle, shape, and apply. Sample PW4, composed of 4% WPA and 0% PET, displayed a significant increase in compressive strength from 46.36 MPa to 49.81 MPa and flexural strength from 10.5 MPa to 11.47 MPa, indicating that incorporating WPA into the mortars can enhance resistance to both compressive and flexural strengths. This same mixture, PW4, demonstrated that the mortars are poor conductors of heat and would be more effective as thermal insulators. Grain segmentation of WPA mortars using Gwyddion software revealed that shorter WPA fibers tend to align with the width, while longer WPA fibers tend to align with the length of the section.

Background and Objectives: Contemporary dentistry focuses on more conservative treatment options such as endocrown restorations and application of dental materials with higher resemblance to tooth structure. Polyether ether ketone (PEEK) polymer is a material used for the fabrication of endocrowns. This study aimed to compare the post-fatigue resistance (PFR) of mandibular first molars restored with PEEK and lithium disilicate (LS2) endocrown restorations. Materials and Methods: This in vitro, experimental study was conducted on 20 human mandibular first molars with similar dimensions. The teeth were prepared for endocrown restoration and were assigned to two groups (n = 10) of PEEK and LS2 endocrowns. After fabrication by the computer-aided design and computer-aided manufacturing (CAD-CAM) technique, the restorations were cemented with resin cement. Next, the teeth underwent 15,000 thermal cycles followed by cyclic loading with 600,000 cycles of compressive force (100 N, 4 Hz) and were then subjected to compressive load application in a universal testing machine. The load causing endocrown failure was recorded as the PFR of the respective restoration. The failure mode was also inspected under a light microscope. Data were analyzed by the independent t-test and also chi-square, Mann–Whitney, and Fisher’s exact tests (α < 0.05). Results: The teeth with PEEK endocrowns showed significantly higher PFR than those with LS2 endocrowns. Irreparable fractures were dominant in both groups. Conclusion: PEEK may serve as a suitable alternative to LS2 for the fabrication of endocrown restorations.

Simulating crop water consumption has been introduced as a valuable decision tool in food security. Such a tool is typically used to support a better understanding of how to increase water-use efficiency to satisfy optimal water management and sustainability. However, climate change is one of the most important and influential factors that restrain sustainable development, agriculture, and food security. Wheat is one of the most important and strategic products in the world and Iran. Therefore, in this study, the impacts of future climate changes on winter wheat yield, water requirement (WR), evapotranspiration (ET), and water footprint (WF) were evaluated in Qazvin Plain, Iran. As such, the outputs from five general circulation models (EC-EARTH, GFDL-CM3, MPI-ESM-MR, MIROC5, and HADGEM2-ES) were fed into the LARS-WG model to get finer spatial climate data for four future periods (P1:2021–2040, P2:2041–2060, P3:2061–2080, P4:2081–2100) considering three emission scenarios (RCP2.6, RCP4.5, and RCP8.5). Thereafter, the projected climate change data were used in the FAO AquaCrop model to simulate the variability of wheat characteristics. The results proved the superiority of LARS-WG to model the maximum and minimum temperatures and precipitation (P) of the baseline scenario (1986–2015). Moreover, results revealed that the wheat WF will decrease in future periods. The modeling results showed that the average wheat yield and biomass will increase in future periods by 7.67 and 15.98 tons/ha, respectively, as compared to the baseline. The highest increase was recorded by the HadGEM2-ES model with RCP8.5 during 2081–2100. The average WR in the baseline was 127.14 mm, which was projected to decrease in future periods. The results show that ET will potentially increase in the period 2021–2040. As a consequence, the adapted methodology produced significantly superior outcomes and can aid in decision-making for both water managers and development planners.

Fine art recognition, traditionally dependent on human expertise, is undergoing a significant transformation with the integration of Artificial Intelligence (AI) and deep learning. This article introduces a novel AI-based approach for fine art recognition, utilizing Convolutional Neural Networks (CNNs) and advanced feature extraction techniques. Addressing the inherent challenges within this domain, we present a systematic methodology to enhance automated fine art recognition. By leveraging critical dataset characteristics such as objective type, genre, material, technique, and department, our method exhibits exceptional performance in classifying fine art pieces across diverse attributes. Our approach significantly improves accuracy and efficiency by integrating advanced feature extraction techniques with a customized CNN architecture. Experimental validation on a benchmark dataset highlights the efficacy of our method, indicating substantial contributions to the interdisciplinary field of fine art analysis.

In the present study, we hypothesized that the presence of gallic acid as an additive antioxidant agent and alendronate can improve the osteogenic differentiation potency of human adipose mesenchymal stem cells, cultured on the scaffolds with fiber-microparticle structures. For this purpose, a combination of electrospinning and electrospraying techniques was employed to prepare a fiber-microparticle structure, composed of polycaprolactone (PCL)–alendronate (ALN) fibers/gallic acid-loaded chitosan nanoparticles (GNP) @ polyvinylpyrrolidone (PVP) microparticles. GNPs were fabricated by a cross-junction microfluidic device. By adjusting the gallic acid concentration, three types of GNPs were fabricated. The morphology of fabricated nanoparticles was quasi-sphere. %Loading efficiency increased by employing higher concentrations of gallic acid. According to dynamic light scattering results, the average hydrodynamic diameter of nanoparticles was between 213 and 217 nm. The impact of ALN concentration on the size and morphology of PCL electrospun scaffolds was separately investigated by SEM in which PCL/ALN 2.5% was selected for the next steps. The % porosity of all samples was around 62–68%. The release profile of ALN was slower than gallic acid. The % 1,1 diphenyl-2-picrylhydrazyl (DPPH) inhibition analysis showed that the presence of gallic acid could effectively improve the additive antioxidant properties of fabricated scaffolds. According to the MTT results, the presence of ALN could significantly improve the proliferation of human adipose mesenchymal stem cells. The alkaline phosphatase (ALP) activity and calcium deposition assessments on days 7, 14, and 21 and the evaluation of mRNA levels of ALP and osteopontin on days 7 and 14 confirmed the synergistic impact of gallic acid and ALN on osteogenic differentiation.

This study proposes a system to store waste heat as liquid hydrogen using a proton exchange membrane electrolyzer (PEME) and a mixed refrigerant hydrogen liquefaction cycle. The novelty of this study lies in proposing a waste heat recovery system that stores electricity as liquid hydrogen, consuming less power due to the improved exergy efficiency of the components. The proposed system is analyzed to achieve better efficiency in terms of thermal and exergy efficiencies. Waste heat is used to generate power by an organic Rankin cycle (ORC), produced electricity is utilized in the PEME unit and compressors of liquefaction cycle to produce and liquefy hydrogen, respectively. Codes are written in EES software to simulate the system. Thermodynamic analysis is done in order to achieve better thermal efficiency for the proposed model. Membrane potential at different values of current density is calculated and compared with validate the simulated model. The exergy efficiency of the liquid hydrogen production process is 57%. The exergy efficiency, rate of power produced in ORC, and rate of hydrogen production by the electrolyzer increase significantly by increasing the isentropic efficiency of the turbine. At a temperature of 340 K for the evaporator, the thermal efficiency of ORC is obtained at 8.5%, which is approximately 3% higher compared with that of the previous similar process.

In the spring of 2019, during preparations for the grand Iranian celebration of Nowruz, a massive flash flood struck “Darvazeh Quarn” in Shiraz, Iran. The flood was triggered by the diversion of a river from its natural course and the inadequate capacity of the drainage channel designed to handle floodwaters at the entrance of Shiraz City. Consequently, floodwaters from the upstream catchment area surged into a crowded parking lot filled with people and vehicles, resulting in significant damage to vehicles and the loss of lives. To analyze the event, a 1D/2D simulation was conducted using PCSWMM to determine the maximum values of depth and velocity. These values were then utilized to calculate the required stability index for vehicles and create a risk map. In this research, the stability or instability condition of cars was determined by employing the curve presented in the Australian Rainfall & Runoff (AR&R) Guideline using the hydrodynamic index of D.V ≤ 0.3. To ascertain the damage values, the HAZUS-MH depth-damage curve was applied. The existing damage models only consider damage based on flood depth, neglecting the impact of velocity in flash floods. To address this gap, the AR&R curve was first extended up to one meter and then integrated with the HAZUS-MH curve. This integration allowed the algorithm proposed in this study to calculate damage values across different depth and velocity ranges. By leveraging the distributive flood risk map produced using the relevant tools in PCSWMM software and considering the parking lot’s capacity, the study estimated that the maximum damage to small cars would be 12%.

Continuous thermal variations cause negative changes in concrete’s physical and chemical properties and can lead to increased permeability. On the other hand, existing methods for measuring concrete permeability are destructive, and the existing theoretical models do not consider the curing age of the concrete. In this study, these issues aimed to be addressed. Concrete samples were prepared and subjected to various thermal variation cycles. Subsequently, the in-situ and non-destructive “cylindrical chamber” method measured the samples’ permeability. Additionally, a new fractal model was employed to assess permeability, incorporating the effect of curing age on permeability. As mentioned earlier, the results obtained from this model showed a 6% difference compared to the laboratory method, indicating the proper accuracy of the new model. This insignificant difference confirms the high accuracy and reliability of our new approach. Furthermore, the “cylindrical chamber” test results demonstrated that 40, 80, 120, and 160 thermal variation cycles increased the concrete’s permeability by 1.4, 1.78, 1.12, and 1.16 times, respectively. In addition, the volume of water that penetrated also increased, consistent with the increasing number of thermal cycles. It is worth mentioning that the mercury test results illustrate that the size of different pores decreases as the curing age increases.

Interlanguage pragmatics has been the focus of many studies since its inception in the 1980s, with several issues being investigated and a variety of approaches being applied. However, studies on the learning processes and strategies which are specifically responsible for the acquisition of interlanguage pragmatics (ILP) knowledge are rare. Therefore, the current investigation sought to examine the effects of selected individual differences (IDs), including age, gender, language learning experience (LLE), and L2 proficiency, on the use of interlanguage pragmatic learning strategies (IPLS) in a sample of 160 English as a foreign language (EFL) learners. The data were collected utilizing a six-point IPLS inventory which contained 58 6-point Likert scale items that were divided into six subcategories. Data analysis using independent samples t-tests revealed that young learners statistically significantly more IPLS compared to their adult counterparts; nonetheless, there were no significant differences in the use of the IPLS between the female and male learners. At the same time, two one-way ANOVAs indicated that LLE and L2 proficiency played a significant role in the use of IPLS, that is, learners with longer LLE and higher proficiency levels used more IPLS. These findings have some pedagogical implications for L2 learners and teachers. Keywords: age, gender, interlanguage pragmatic learning strategies (IPLS), language learning experience (LLE), L2 proficiency

A dinuclear copper complex, [Cu2(teaH)(pNBA)2(H2O)2]·MeOH·pNBH (1) (where teaH3 = triethanolamine, pNBH = 4‐nitro‐benzoic acid, and pNBA = 4‐nitro‐benzoate) has been prepared and structurally characterized. In 1, there is an interesting intermolecular structure that is shown as a tetramer copper connected in chain‐like motif. In the UV‐Vis spectrum, higher absorbance at 267 nm is referred to n → π* transition, coupled with a weak peak at 500 nm, indicating another transition, which is specified as metal‐to‐ligand charge transfer. The higher intensity peak in the photoluminescence spectrum is marked as the absorption of energy required for the excitation of electrons, whereas lower intensity peaks show the emission of energy, which describes d‐d transitions of Cu (II) electrons due to d⁹ configuration. Complex 1 was explored for the adsorption of methylene blue (MB) dye, with the maximum adsorption as 101.07 mg/g, whereas the removal efficiency was estimated to be 81.05%. In conformity with the kinetic studies, the adsorption process proceeded via a Pseudo‐first‐order kinetic model. The incorporation of mixed ligands such as teaH3 and pNBH in 1 tends to increase the dimensionality that led to increased MB adsorption. The plausible mechanism behind the adsorption was favored by hydrogen‐bonding, electrostatic, π–π, and n–π* interactions, operating between the dye and complex 1. Further, the H‐bonding and these interactions provided stability to the complex, and an improved dye adsorption was observed even during the 2nd and 3rd recyclability experiments. Additionally, complex 1 corroborated remarkable stability after dye adsorption, allowing for up to four recycling turns. The magnetic study revealed antiferromagnetic coupling between the two magnetic centers with a singlet ground state (S = 0).

Investigating the phenomenon of topographic amplification and the seismic response of the site is an important issue that has already attracted the attention of many researchers. The studies and researches conducted in the field of topographical effects and also the phenomenon of the amplification of earthquake waves in passing through surface layers have shown that topography has a great impact on the amount of damage caused by earthquakes. The local topographic characteristics amplify the strong movements of the ground during an earthquake and ultimately cause great damages. In this article, the effects of a site (take, for example, one of the most common topographical forms in nature, such as a semi-sinusoidal hill) on the seismic response of the earth’s surface subjected to vertically propagating shear vertical (SV) waves have been studied using FLAC 2D, a two-dimensional finite-difference program. In the numerical modeling, the elastic linear behavior has been used. In this regard, in order to investigate the effects of layering on the response of semi-sine hills, two-layered and three-layered hills with different layering characteristics and thicknesses are considered the basis of this article. In this research, the effect of soil characteristics, layering thickness, and the position of the loose layer has been investigated. From the obtained results, it can be concluded that the characteristics and thickness of the layering and the position of the loose layer have effects on the general trend of amplification on top of the hills and de-amplification near the toe of hills in response to horizontal motion for acceleration, velocity, and displacement components.

The current investigation proposes a novel hybrid methodology for the diagnosis of the foot fractures. The method uses a combination of deep learning methods and a metaheuristic to provide an efficient model for the diagnosis of the foot fractures problem. the method has been first based on applying some preprocessing steps before using the model for the features extraction and classification of the problem. the main model is based on a pre-trained ZFNet. The final layers of the network have been substituted using an extreme learning machine (ELM) in its entirety. The ELM part also optimized based on a new developed metaheuristic, called enhanced snow ablation optimizer (ESAO), to achieve better results. for validating the effectiveness of the proposed ZFNet/ELM/ESAO-based model, it has been applied to a standard benchmark from Institutional Review Board (IRB) and the findings have been compared to some different high-tech methods, including Decision Tree / K-Nearest Neighbour (DT/KNN), Linear discriminant analysis (LDA), Inception-ResNet Faster R-CNN architecture (FRCNN), Transfer learning‑based ensemble convolutional neural network (TL-ECNN), and combined model containing a convolutional neural network and long short-term memory (DCNN/LSTM). Final results show that using the proposed ZFNet/ELM/ESAO-based can be utilized as an efficient model for the diagnosis of the foot fractures.

This article presents a novel approach for solving the general Lane–Emden type equation with the quantum spectral method. This equation is a nonlinear initial value problem. We use a successive linearization to convert our problem to a linear system of equations, which is solved by a simple iteration method. This method is an iterative algorithm by combining quantum computing, pseudo-spectral, and successive linearization methods. In each iteration, we used a quantum algorithm and the final quantum state can be obtained by adding the quantum state in each iteration. Some numerical examples are considered and comparison with other existing methods, shows the efficiency of the method.

The presence of unexpected conditions on the road increases the risk of collisions for drivers. To effectively manage these risks, drivers must first accurately perceive hazards and then respond appropriately. The behavior of drivers and their responses to potential road hazards are investigated in this study. It is possible that one motorist may opt to gradually reduce the velocity of their vehicle, while another individual in the same situation might opt for forceful braking at the moment of initial awareness. This indicates the divergence reactions of drivers to identical hazards. This study introduces the hazards response scale (HRS) as a metric to assess the differences in hazard response among participants and its effect on safe driving by undertaking a driving simulation study. The results reveal that a lower HRS index correlates with a higher level of driving safety. By evaluating the relationship between demographic variables and HRS, it was found that increasing age and driving experience are associated with lower HRS scores, thus enhancing driving safety. Notably, women exhibit lower HRS values than men, suggesting that they tend to drive more safely.

Managing chronic, refractory nausea and vomiting in advanced cancer patients is challenging, especially when unrelated to cancer treatment. Mirtazapine, a tetracyclic antidepressant, effectively alleviates these symptoms, improving quality of life. It offers a promising palliative care alternative, addressing multiple symptoms and reducing polypharmacy, thereby enhancing patient satisfaction.