Iran University of Science and Technology

The Heck reaction is one of the most well-known C–C (carbon-carbon) coupling reactions and was identified with the Nobel Prize in Chemistry in 2010. These reactions have been broadly utilized to prepare a different spectrum of heterocycles with applications in agrochemical and pharmaceutical industries. These reactions are commonly catalyzed by palladium due to its tolerance and expansive variousness of functional groups, which bears a remarkable power in creating C–C bonds. Carbohydrate chemistry is a significant and crucial part of the organic chemistry field. Among existing carbohydrates, β-cyclodextrins (β-CDs) are natural cyclic oligosaccharides that contain glucose monomers and have played an active role in nearly every industrial and scientific field, attention and interest in them never aged. CDs can be utilized as a beneficial catalyst in numerous aqueous organic conversions. Their derivatives have demonstrated remarkable activity in water-mediated organic synthesis and are currently of continuing interest to multiple scientists in different fields. Being non-toxic, accessible, biodegradable, readily functionalized, low-cost, renewable, and producible in large-scale amounts are several of the benefits of CDs that make them a suitable nominee for catalyst applications. Different β-CDs catalysts have recently been widely employed for various C–C bond coupling reactions like the Heck coupling. Here, we review the latest advancements in using CD-based catalysts for Heck reactions.

Aluminum Magnesium Boride (BAM), an intermetallic compound, exhibits exceptional hardness, a low coefficient of friction, low density, high electrical conductivity, and outstanding thermoelectric properties. These characteristics make it a promising candidate for applications in semiconductors, as a reinforcing agent in metal and ceramic matrix composites, and as a wear-resistant coating across a wide range of temperatures. In this work, BAM nanoparticles were prepared by high-energy ball milling of constituent as a solid-state route. BAM was synthesized by spark plasma sintering of Al 12 Mg 17 intermetallic and B powders. The powders with a stoichiometric ratio were mechanically milled and sintered by SPS (40 MPa/ 1400 °C/ 5 min). It was found that the use of Al 12 Mg 17 intermetallic compound as a precursor (in comparison to the use of elemental Al and Mg) gives a high efficiency (≈92%) to synthesize BAM material with a hardness (27.98 ± 0.9 GPa) and density (2.68 ± 0.002 g/cm ³ ) close to the theoretical values. Finally, the BAM nanoparticles (the mean diameter of 32.4 nm) were successfully obtained by mechanical milling of the bulk sample, for the first time.

The growing demand for renewable energy sources has made solar energy an ideal choice due to its unlimited and readily available nature. Direct and indirect absorption parabolic solar collectors are widely used to harness solar energy for water heating in laboratory and industrial applications. In this research, modifications were made to the absorber tube to enhance the efficiency of a Direct Absorption Parabolic Trough Collector (DAPTC). Fiber laser processing is applied to copper surfaces placed at the center of the absorber tube. The spectroscopy technique was used to analyze the main laser parameters, including frequency, speed, and power. It was determined that applying a laser with a frequency of 20 kHz, a speed of 20 mm/s, and 80% of the power of a 30 W laser machine significantly reduces surface reflection. Various patterns, including horizontal lines, vertical lines, and circle patterns, were engraved on the surfaces to evaluate their impact on heat transfer and thermal efficiency improvement. The findings are presented based on an experimental approach, wherein a system was constructed to investigate these effects, and the relevant considerations are discussed. The results indicate that using an unprocessed copper surface increases the thermal efficiency of the collector by up to 32.83%. When laser-processed surfaces with different patterns are used, this increase reaches up to 38.99%. The maximum pressure drop across these surfaces is reported to be 247 Pa, and the performance index ranges between 0.84 and 1.06, indicating the effective operation of the collector using these surfaces.

Aeroacoustic analysis of a small vertical-axis Darrieus wind turbine suitable for urban area applications is performed using numerical simulation and acoustic analogy. The analysis is performed for two helical wind turbine models with three- and four-blade configurations and under different operating conditions. Numerical simulations are performed using the unsteady Reynolds averaged Navier-Stokes method, along with the Ffowcs-Williams and Hawkings aeroacoustic analogy. Validation of the performance of the computational model against experimental data demonstrates its ability to accurately predict the aerodynamic and aeroacoustic behavior of the turbine. The influence of the number of turbine blades and their distance from the center of the turbine on the generated noise is analyzed. The analysis is further focused on the highest power coefficient, obtained at the tip speed ratio of 1.8, and the sound pressure level (SPL) curves recorded by the receivers are analyzed. Predictions show that while the four-blade turbine has a higher SPL than the three-blade one at a downstream position of about four turbine diameters, the situation is reversed at farther downstream positions. The aeroacoustic findings of this research have direct implications for the proper installation of small vertical-axis Darrieus wind turbines in urban areas, where wind turbine generated noise is important.

The study investigated the effects of different selenium concentrations on the growth variables of Arthrospira platensis EP44 and its ability to accumulate selenium. The maximum growth variables, including final biomass concentration and linear growth rate, were observed at 5 mg L⁻¹ Na2SeO3. The highest level of selenium bioaccumulation was observed at 70 mg L⁻¹ Na2SeO3. Based on both the growth variables and selenium accumulation, the optimal selenium concentration to produce enriched A. platensis EP44 was determined to be 5 mg L⁻¹ Na2SeO3. Then, the effect of Na2SeO3 at 5 mg L⁻¹ was studied on phytochemicals in A. platensis EP44, including protein and sugar contents, phenolic compound, photosynthetic pigments, fatty acid, and antioxidant activity. The highest levels of soluble protein, flavonoid, soluble sugar, photosynthetic pigments, and antioxidant activity were observed at 5 mg L⁻¹ Na2SeO3 compared to the control group. Additionally, A. platensis EP44 treated with 5 mg L⁻¹ Na2SeO3 showed an increase in unsaturated fatty acid content and a decrease in some saturated fatty acids. The findings indicate that A. platensis EP44 enriched with selenium at an optimal concentration is could be recommended as antioxidant food supplement for human health.

Introduction Oriented grating is usually employed in visual science experiments as a prominent property of neurons in the visual cortices. Previous studies have shown that the study of mouse vision can make a significant contribution to the field of neuroscience research, and also the local field potential (LFP) analysis could contain more information and give us a better view of brain function. Methods In this research, cross‐frequency coupling is employed to assess the grating orientation perception in V1 and lateromedial (LM) of 10 mice. The experimental data were collected using chronically implanted multielectrode arrays, involving area V1 recording of five mice and area LM recording of five mice separately, performing a passive visual task. Two criteria known as phase–amplitude coupling (PAC) and amplitude–amplitude coupling (AAC) were exploited to analyze the characteristics of cross‐frequency coupling of LFP signals in the experiment consisting of first‐order and second‐order drifting sinusoidal grating stimuli with different orientations. Results It was found that in area LM the correlation between phase of lower than 8 Hz band signal and amplitude of above 100 Hz band signal can be significantly different for orientations and stimulus conditions simultaneously. In area V1, this difference was observed in amplitude correlation between 12 and 30 Hz and more than 70 Hz subbands. Conclusions In conclusion, PAC and AAC can be proper features in orientation perception detection. Our results suggest that in both areas, the significant role of high‐band and low‐band oscillations of LFPs discloses the reliability of these bands and generally LFP signals in mice visual perception.

Correction for ‘Effects of morphology and size of nanoscale drug carriers on cellular uptake and internalization process: a review’ by Wenjie Zhang et al., RSC Adv., 2023, 13, 80–114, https://doi.org/10.1039/D2RA06888E.

Despite the sharing economy’s rapid growth, a significant knowledge gap remains in understanding how innovation emerges and diffuses through technological collaboration networks. While prior studies have examined business models and social impacts, the mechanisms of technological advancement, especially via patent collaborations, are less explored. This study addresses these gaps by conducting a comprehensive patent analysis, leveraging Social Network Analysis (SNA) and text mining to map collaboration patterns, influential entities, and emerging technological trends within sharing economy patents. Through centrality analysis and community detection, the research uncovers key players such as Microsoft Corp, SAP, IBM, and Oracle Int Corp, and identifies major technological clusters, including Digital Asset Management and Blockchain Social Networking. These insights support strategic decision-making for corporations, SMEs, policymakers, and researchers, offering a robust empirical foundation for understanding innovation dynamics in the sharing economy. This study represents the first detailed mapping of technological collaboration within this sector.

Stabilizing and improving weak and poorly graded soils in road construction projects is a widely used and highly interesting technology. This research study utilizes paper sludge ash (PSA) residues as a geopolymer waste material to stabilize loose and poorly graded sands (SP), improve mechanical properties, and support sustainable pavement development. Geotechnical tests using the unconfined compressive strength test (UCS), Young’s modulus (Es), California bearing ratio (CBR), and a direct shear test (DST) assessed the performance and strength development of geopolymer-stabilized soil. The stabilized soil’s microstructure and chemical mineralogy were also examined using SEM and XRD. Additionally, a laboratory testing apparatus was designed and developed to assess the permanent strain behavior of subgrade soil and geopolymer-stabilized soil layers under cyclic loading. The research analysed variables including curing duration (1, 3, and 7 days), PSA concentration (5, 10, and 15%), and the type and concentration of alkaline activators (NaOH or Na₂SiO₃). Soil samples treated with PSA and Na₂SiO₃ geopolymers showed higher UCS, Es, and CBR values, leading to improved strength from increased N-A-S-H and C-A-S-H gel formation among sand soil particles. On the contrary, the NaOH solution enhanced the strength parameter of geopolymer-stabilized soil samples. The results showed that geopolymer-stabilized soil significantly improved its resistance to permanent deformation after applying loads. The mineralogical examination also shows a high concentration of lime and cubic aluminate, which may be active cementitious pozzolanic material. This research reflects that PSA has promising potential to stabilize sandy soil and improve the design and maintenance of roads and infrastructure in areas with weak soils.

Multiplexed Laguerre–Gaussian (MLG) beams have garnered significant interest due to their unique properties arising from the superposition of independent Laguerre–Gaussian (LG) beams. Researchers explore MLGs for applications in optical communications, quantum computing, and precise manipulation of trapped particles, offering promising avenues for advancing optical technologies and high-dimensional quantum states. In this study, a straightforward technique for generating and rotating the MLGs has been explored. By introducing an easily controllable additional degree of freedom, rotation of the transverse profile, the data transmission capabilities of MLGs can be enhanced and precise manipulation of trapped particles can be achieved. The proposed approach has been experimentally and computationally validated, and methods for controlling rotation speed, direction, and halting have been provided. The proposed straightforward and easy-to-use technique can enhance the MLG application in various optical fields.

The accurate estimation of methane generation in landfills is crucial for effective greenhouse gas management and energy recovery, requiring site-specific assessments due to the inherent variability in waste composition and properties before and after disposal. This study investigates the uncertainties associated with methane generation predictions by employing a combination of stoichiometric methods, Biochemical Methane Potential (BMP) assays, and Bayesian inference. Fresh and aged (1-year-old and 5-year-old) samples collected in the tropical Saravan dump site in Gilan, Iran, were used to evaluate the waste’s methane generation potential and degradation rate in the field. The average methane generation potential (L0) for fresh samples by the stoichiometric simplified method was 83.4 m3 CH4/Mg MSW, which decreased to 44.8 m3 CH4/Mg MSW and 32.8 m3 CH4/Mg MSW for 1-year-old and 5-year-old waste samples, respectively. The BMP tests led to similar results, further validating the decreasing trend of L0 with waste age. The Bayesian approach combined with MCMC simulations revealed that uncertainty in methane estimation is highest in the early years and gradually declines as waste stabilizes, improving long-term prediction accuracy. By integrating sensitivity analysis with Bayesian inference, this study advances uncertainty quantification approaches, addressing limitations in existing landfill methane estimation models. This innovative framework identifies the most influential parameters, providing a robust foundation for refining predictive models. The decay rate constant (k) was determined to be 0.26 year−1, aligned with the guidelines for humid areas. Notably, the highest standard deviation in methane estimation was observed during the initial post-disposal years, reaching 1,384,751.5 m3 CH4/year using the BMP method and 2,266,762 m3 CH4/year with the simplified method, highlighting how early-stage variability impacts overall methane predictions, emphasizing the critical need for site-specific data. These insights contribute to improved landfill gas management strategies and support decision-making for sustainable waste management practices. Implications: This research underscores the importance of integrating methodologies like stoichiometric analysis, BMP assays, and Bayesian inference to enhance methane generation estimates from landfills. A significant outcome is the recognition of the inherent uncertainty in key parameters, particularly ultimate methane potential and decay rate constant. By employing Bayesian inference and Monte Carlo simulation, we quantified the uncertainty associated with these parameters and analyzed its influence on methane production predictions. The findings reveal that different methodologies yield varying levels of uncertainty, highlighting the necessity for a comprehensive framework that utilizes site-specific data. This approach not only improves the reliability of methane estimates but also informs greenhouse gas management strategies, fostering more effective decision-making in waste management practices.

This research paper intends to analyse the behaviour of adhesively bonded joints (ABJs) under mode-II quasi-static and impact loads. The study involved the use of tensile and drop-weight tests on end-notched flexure specimens (ENF) to determine the ABJs mode-II quasi-static and impact fracture responses at varying impact energies. To obtain the quasi-static and impact mode-II fracture energies, the compliance-based beam method (CBBM) was used. The results revealed that changing the loading condition from quasi-static to impact led to significant decreases in the maximum load and fracture energy of ABJs by 17.4% and 17.8% respectively. Furthermore, increases in impact energy resulted in decreases of 7.6% and 6.8% in maximum load and fracture energy within the impact test conditions. To model the quasi-static and impact fracture responses of adhesive joints, the cohesive zone model (CZM) was employed using a bi-linear traction-separation law obtained from a semi-direct method. A subroutine was also utilized to obtain more precise damage behaviour under impact loading, accounting for the rate-dependent behaviour of adhesives under different strain rates. The experimental and numerical results were in reasonable agreement.

Rods, tubes, and similar components undergo the rotary swaging process to reduce cross-sectional area and enhance mechanical properties. This process offers significant advantages, including increased tensile strength, material strength improvement, reduced surface roughness, and reduced scraps. However, its use in producing double-wall tubes has been less common. This work investigated the rotary swaging process for producing aluminum-copper bimetallic double-wall tubes with an aluminum coating. The research specifically examines the impact of the presence or absence of a mandrel during the rotary swaging process on the mechanical properties of these double-wall tubes. The results indicate that using a mandrel not only enhances adhesion and sample strength but also leads to increased hardness in both axial and radial directions. Additionally, microscopic analyses, including optical microscopes (OM) and scanning electron microscopes (SEM) equipped with energy dispersive spectroscopy (EDS), and mechanical tests such as compression, peeling, hardness measurements, and bending tests confirm that mandrel-assisted samples exhibit more desirable mechanical properties. Without the use of a mandrel, the layers are not effectively bonded together, resulting in gaps in certain areas, the average of which is about 11.95 μm. Additionally, the yield stress for double-layer tubes without a mandrel is equal to 153 MPa, whereas the yield stress for double-layer tubes with a mandrel is equal to 170 MPa, indicating that the samples produced with a mandrel are stronger than those without.

This paper introduces a novel, non-destructive, and preventive method for monitoring chloride ion penetration in concrete, replacing conventional techniques. While previous research has focused on using sensors to detect rebar corrosion, this study prioritizes preventive measures to monitor chloride ion penetration depth and prevent corrosion. We utilized carbon-based substrate (CPS) sensors, cement pseudo-reference electrodes (GS1, GS3, GSAg), and steel 316 ladder (L316) sensors. The results demonstrate that these sensors effectively provide real-time data on chloride ion penetration via an Internet of Things (IoT) platform. This system can prevent further ion infiltration, thus reducing corrosion risks. The sensors’ performance was validated by comparing them with chloride profile tests. The penetration rate was also compared to Fick’s second law diffusion rate, showing a 21% difference, confirming the reliability of the sensors for long-term structural health monitoring.

This article examines the influence of annealing temperature on fracture toughness and forming limit curves of dissimilar aluminum/silver sheets. In the cold roll bonding process, after brushing and acid washing, the prepared surfaces are placed on top of each other and by rolling with reduction more than 50%, the bonding between layers is established. In this research, the roll bonding process was done at room temperature, without the use of lubricants and with a 70% thickness reduction. Then, the final thickness of the Ag/Al bilayer sheet reached 350 µm by several stages of cold rolling. Before cold rolling, it should be noted that to decrease the hardness created due to plastic deformation, the roll-bonded samples were subjected to annealing heat treatment at 400 °C for 90 min. Thus, the final samples were annealed at 200, 300 and 400 °C for 90 min and cooled in a furnace to examine the annealing temperature effects. The uniaxial tensile and microhardness tests measured mechanical properties. Also, to investigate the fracture mechanism, the fractography of the cross-section was examined by scanning electron microscope (SEM). To evaluate the formability of Ag/Al bilayer sheets, forming limit curves were obtained experimentally through the Nakazima test. The resistance of composites to failure due to cracking was also investigated by fracture toughness. The results showed that annealing increases the elongation and formability of the Ag/Al bilayer sheet while reduces the ultimate tensile strength and fracture toughness. However, the changing trend is not the same at different temperatures, and according to the results, the most significant effect is obtained at 300 °C and aluminum layers. It was also determined that by increasing annealing temperature, the fracture mechanism from shear ductile with small and shallow dimples becomes ductile with deep cavities.

The thermal efficiency of a flat‐plate solar collector is theoretically analyzed in this study. For this purpose, a novel computational technique called the Akbari‐Ganji method (AGM) is applied. The solution function derived using this method is examined for three different cases, including four‐term, six‐term, and eight‐term approximations. To validate the proposed method, the obtained results are compared with those from a published work, showing very good agreement. The thermal efficiency of the collector is comprehensively assessed under the influence of collector length, effectiveness coefficient, and heat loss coefficient. The results reveal that an increase in the effectiveness coefficient enhances the collector's thermal efficiency.

Biobased adsorbents such as chitosan due to nontoxic nature, biocompatibility, and accessibility can be used to blend with other polymers to develop their physical and chemical features. This study aims to fabricate a highly efficient adsorbent through the functionalization of Chitosan- Poly(Vinylpyrrolidone) (PVP) beads with l-arginine. The prepared nano-sorbent was well characterized via various analytical methods such as FTIR, BET, EDS, XRD, FESEM, and TGA and applied in the removal of amoxicillin and Hg (II). The optimal conditions for higher performance were assessed with the optimization of different factors including pH, dosage, time, and initial concentration for both pollutants. The prepared composite has demonstrated considerable adsorption capacity toward Hg(II) and amoxicillin with the highest adsorption capacities of 313.162 mg/g and 2800 mg/g, respectively, confirming the composite’s various adsorption mechanisms. Accordingly, the composite mostly follows the pseudo-second-order kinetics and the Langmuir adsorption isotherm model. The extraordinary adsorption capacity with the accompaniment of the porous structure of the prepared composite has a promising application for high-performance wastewater treatment. Graphical abstract

A copper-doped fluorohydroxyapatite (Cu-FHAp) coating was successfully electrodeposited onto anodized and non-anodized AZ31 alloy using a pulse-reverse method combined with ultrasonic agitation. The effects of anodizing and ultrasonic agitation on the performance characteristics of the Cu-FHAp coating deposited on the AZ31 magnesium alloy surface were studied. The results reveal that ultrasonication reduces coating thickness while enhancing uniformity and density. Anodizing increases roughness and diminishes hydrophobicity. Coatings produced under ultrasonic conditions displayed reduced hydrophobicity and improved cell attachment but lower corrosion resistance. In contrast, coatings formed on anodized alloys through stirring achieved optimal characteristics, benefiting from the protective properties of interlayer MgO.

Understanding the interaction of flow and vegetation in open canals has a great impact on better implementation of environmental projects and hydraulic engineering. The purpose of this research is to apply spatiotemporal (spatial and temporal) averaging method in concrete canals in the presence of vegetation patches. Therefore, in this research, four reaches of irrigation canals with vegetation patches were investigated in Iran. The measured data includes flow velocity and reaches surveying. The results of spatiotemporal velocity profiles showed that the log-law fits nicely the measured velocity data near the bed with vegetation patches. The local values of velocity and shear velocity were compared with the unit value extracted from the double-averaged velocity profile. The results of this comparison showed that the percentage difference between the local values resulting from each flow velocity profile and the unit value of the spatiotemporal velocity is not significant in most cases. Thus, the spatiotemporal velocity method is able to reflect the characteristics of the entire flow conditions in concrete canals in the presence of vegetation patches.