IRANIAN JOURNAL OF CHEMISTRY AND CHEMICAL ENGINEERING
Year:2024 | Volume:43 | Issue:3|Papers Count:33

The use of smart materials to deliver anticancer drugs to tumors has been considerably increased in cancer therapy. In this work, a novel pH-responsive system for drug delivery is proposed that employs magnetite nanoparticles and bentonite loaded with doxorubicin (DOX), a known anticancer drug, to investigate its loading capacity and release. This magnetic bentonite nanohybrid is first synthesized using a single-step method. The structural and spectral properties of the nano-assemblies are analyzed employing a variety of analytical methods including Fourier Transform InfraRed (FT-IR) spectroscopy, Scanning and Transmission Electron Microscopy (SEM and TEM, respectively), X-Ray Diffraction (XRD), and Vibrating Sample Magnetometer (VSM). The drug-loading capacity, entrapment, and yield are compared with different ratios of 1:1, 1:2, and 1:4 of the drug: nanohybrid to choose the best ratio. Moreover, a pH-sensitive release is measured at pH 7.4 and 5.5 with a total release of 57% and 80% after 72 h, respectively. Considering all these findings, the magnetic bentonite shows significant promise as a potential candidate for drug delivery applications targeting cancer cells.

There is a growing interest in the development of environmentally friendly synthesis methods for nanomaterials. The purpose and also the novelty of this study is to investigate the hydrothermal synthesis of CuO nanoparticles using natural materials as both reducing and capping agents. The focus is on assessing the photocatalytic properties of the synthesized nanoparticles for the degradation of organic dyes. The CuO nanoparticles were prepared through a hydrothermal synthesis method. Kiwi juice and Sumac extract were used as both the reducing and capping agents in this novel synthesis approach. The resulting brown precipitate was subjected to characterization using various techniques such as SEM, TEM, XRD, FT-IR, and EDS. The results provided insights into the size, morphology, crystallinity, and elemental composition of the nanoparticles. Furthermore, the photocatalytic performance of the synthesized CuO nanoparticles was evaluated by testing their ability to degrade Rhodamine B dye. The results showed that the nanoparticles achieved a dye removal efficiency of up to 83% within 40 minutes of UV light irradiation.

Utilizing two distinct experimental techniques, the cobalt(II) metal-organic compound denoted as (Co-MOC), [Co(L)2(H2O)4], where L = pyridine-3-carboxylic acid) has been successfully synthesized: branched tube and sonochemical strategies. Notably, both methods yielded identical macro and nanostructures. Characterization of the nano compound involved the application of Scanning Electron Microscopy (SEM), Powder X-Ray Diffraction (PXRD), and Fourier Transform InfraRed (FT-IR) spectroscopy. Single-Crystal X-Ray Diffraction (SCXRD) analyses of compound Co-MOC revealed the coordination of Co2+ ions in a hexacoordinated environment. Furthermore, the scope of the investigation encompassed an in-depth examination of how various variables, such as temperature, reaction time, reactant concentration, and sonication energy, impact both the process of formation and the ultimate morphology of the compound synthesized through the sonochemical approach. Additionally, the research delved into an extensive exploration of diverse analytical methodologies. This included the application of techniques such as Thermal Gravimetric Analyses (TGA) and Differential Thermal Analyses (DTA) to elucidate changes in weight and temperature-driven behaviors within the samples. Moreover, compound Co-MOC underwent comprehensive scrutiny using Hirshfeld Surface Analysis (HAS) to unravel insights into its crystal packing and the intermolecular interactions present. Biological activity assessment involved testing the synthesized compounds against two bacterial strains:  gram-negative Escherichia coli (E. coli) and gram-positive Staphylococcus aureus (S. aureus). Notably, the compounds exhibited noteworthy antibacterial efficacy within a non-living environment.

In this study, the removal efficiency of ceftriaxone (CTX) from aqueous media was assessed via nano zero-valent iron (nZVI) incorporated with strontium hexaferrite (SrFe12O19) (nZVI/SrFe12O19). The synthesized adsorbent was characterized using Scanning Electron Microscopy (SEM), Energy Dispersive X-ray (EDX), Fourier-Transform InfraRed (FT-IR), spectroscopy, and X-Ray Diffraction (XRD). The experiments with different parameters such as pH, adsorbent dosage, and initial concentration were designed. Two artificial intelligence methods, including the Fuzzy Inference System (FIS) and Adaptive Neuro-Fuzzy Inference System (ANFIS) were used to model for predicting the percentage of CTX removal. The mean recovery value was found to be 100.03% and 100.0006% for FIS and ANFIS, respectively. Root mean square error (RMSE) and mean absolute percentage error (MAPE) were 0.1291, 0.0384%, and 0.0026, 0.0105% for FIS and ANFIS, respectively. These results represent that both FIS and ANFIS models are capable of predicting the removal percentage of CTX with high precision and accuracy. It can also be said that the ANFIS model indicated a higher predictive ability than the FIS model based on the good agreement with predicting values of experimental data. The nZVI/SrFe12O19 can be used effectively to overcome contamination problems posed by antibiotics in the environment.

Polyethersulfone membrane modification by placing hydrophilic nanoparticles in the membrane matrix can improve antifouling ability. In this study, the Fe3O4 nanoparticles were modified by immobilizing SiO2, KCC-1, GMSI, and Carnosine. After surface modification, the nanoparticles were brought into polyether sulfone-based nanofiltration membranes to improve the membrane permeability, separation efficiency, and antifouling ability. The effect of nanoparticles on membrane structure and its performance was investigated using Field Emission Scanning Electron Microscopy (FE-SEM), Atomic Force Microscopy (AFM), water contact angle, mean pore size and porosity measurements, pure water flux, and wastewater treatment, as well as antifouling ability. Based on the results, increasing the concentration of nanoparticles from 0 to 0.1 wt% developed the membranes to a more porous structure in the sub-layer, higher thickness, increased pure water flux, higher hydrophilicity, and fouling resistance. Consequently, the membrane with 0.1 wt% of nanoparticles endorsed a decreasing contact angle from 76 ±1 to 60.3±0.2, increasing pure water flux from 50.96 L/m2h to 93.42 L/m2h at a pressure of 9 bar, and a relatively high flux recovery ratio of 95.5%. Thus, a considerable performance of the prepared membrane was established in treating the oily wastewater contaminants.

A one-step green synthesis approach has been used successfully to synthesize undoped and Sm-doped calcium titanate nanoparticles (NPs). In particular, we prepared undoped and Sm-doped CaTiO3 NPs using Tridax procumbens leaf extract as the catalyst for the first time. From XRD analysis, the calculated crystallite size is 23.92 nm and 24.32 nm, respectively, for undoped and Sm-doped CaTiO3 samples. From the UV-Vis analysis, the calculated band gap is 3. 59 eV and 3.56 eV respectively for the undoped CaTiO3 and Sm-doped CaTiO3 nanoparticles. Owing to their distinctive morphologies, flower-like CaTiO3 NPs possess a high level of photocatalytic activity when exposed to UV light. As a result of varying degradation times, the synthesized material was used to photodegrade methylene blue dye. Under UV light irradiation, undoped and Sm@CaTiO3 exhibited effective photocatalytic properties, which may explain the existence of active oxygen and hydroxyl radicals. During the cyclic activity, CaTiO3 doped with Sm did not exhibit any changes in phase or structure, proving that it is highly stable during degradation.

The adsorption of zinc, lead, and copper ions onto silica gel adsorbent has been successfully carried out in this study. Linear regression of polynomial transformation from input variables was employed to model the correlation between estimator variables (adsorbent dose, initial concentration, contact time, and pH) and output variable (%removal). Although the R2 scores varied, overall, the models performed well in predicting metal ion removal. The regression coefficients of the models revealed that adsorbent dose and pH were the most significant factors for zinc and copper adsorption, while initial concentration and contact time also have a significant role in lead adsorption. Bayesian regression was used as a complementary approach to Response Surface Methodology (RSM), revealing different weight distributions for zinc and copper adsorption compared to RSM polynomial regression. The study concludes that copper and lead adsorption using RSM are more reliable compared to zinc, and suggests further optimization of factors or levels for more accurate results. The use of Bayesian regression provides valuable insights into variable weights and can improve the optimization process. Overall, this study provides useful information for designing efficient metal ion adsorption processes. This study provides useful insights for future research on the competition for metal ions in adsorption processes.

In this study, iron oxide, silver, and copper were used to create a Fe2O3/Cu/Ag nanocomposite to remove tetracycline (TC) as pollutants from aqueous solutions. Various techniques were employed to analyze the composite structure, including X-Ray Diffraction (XRD) crystallography, Transmission Electron Microscopy (TEM), scanning electron microscopy (SEM), Energy-Dispersive X-ray (EDS) spectroscopy, mapping, and Fourier Transform InfraRed (FT-IR). The impact of environmental pH, reaction time, temperature, and the maximum amount of TC on removal efficiency was investigated. The findings showed that an optimal pH of 5, 150 mg of Fe2O3/Cu/Ag, and 20-minute reaction time at room temperature resulted in 98.53% removal of tetracycline. In conclusion, Fe2O3/Cu/Ag adsorbents show promise for effectively eliminating tetracycline from aqueous environments.

This work is a study of the optimization of the removal of a textile azo dye namely Direct Violet 51 (DV 51) by heterogeneous solar photocatalysis onto ZnO and TiO2. The Response Surface Methodology (RSM) was applied to design the experiments and to investigate the interactions between the physical parameters including the type of catalyst. Based on the results, a degradation efficiency of 100 % was obtained for the ZnO/Solar light system in the optimal conditions (catalyst dose = 0.1567 g/L, CO = 10 ppm, and reaction time = 120 min). Appropriate figures of merit were selected for evaluating the energy requirement for DV 51 removal. The estimation of collector area per order and electric energy per order confirmed that the ZnO photocatalytic system used the introduced light more efficiently both under artificial and solar light. According to the scavenging mechanism study, superoxide (O·2-) and electrons (e-) are the main species responsible for DV 51 degradation by ZnO.

The increasing industrialization leads to toxic pollutants in wastewater and it has a considerable impact on human health due to toxicity, accumulation, and persistence in nature. The study concentrated on the adsorption of chromium (VI) ions using groundnut shells modified with phosphoric (PA-GNS) and citric acid (CA-GNS) in aqueous solutions. Several factors were examined, encompassing contact time, pH, adsorbent dose, and initial chromium concentration, were systematically examined to understand their impact on the adsorption process. The findings revealed that, under optimized conditions of pH 2, stirring speed at 200 rpm, initial metal ion concentration of 50 mg/100 mL, adsorbent dose of 1500 mg/100 mL solution, a contact time of 120 minutes (45 minutes for PA-GNS) for stirring, and a temperature of 25°C, the maximum removal percentages for Cr(VI) were 96.95% and 93.69% for PA-GNS and CA-GNS, respectively. The biosorption of Cr(VI) ions by both PA-GNS and CA-GNS was found to conform to the Langmuir and Freundlich isotherm models. Regarding the kinetics of the adsorption process, it followed a pseudo-second-order model with rate constants of 3.25 and 3.311 (g/mg.min) for PA-GNS and CA-GNS, respectively.

The adsorption complexes and the binding energies of a series of aliphatic alcohols on Ti and P-modified acidic zeolites have been studied computationally employing combined Quantum Mechanics/Molecular Mechanics (QM/MM) methods suited for large-scale calculation. The investigation has been carried out using an extended 84T cluster model with one hydroxyl Brønsted acidic site. This cluster model has been studied employing the hybrid (QM/MM) B3LYP/6‑31+G(d,p):UFF method and its counterpart B3LYP‑D3/6‑31+G(d,p):UFF level of theory accounting for dispersion forces. The use of the B3LYP-D3 technique has led to a considerable improvement in the B3LYP results, underlining the critical role of the long-range dispersion forces. The modification exhibits higher deprotonation energies and a decreasing acidic character.The modified clusters show a considerable reduction of the order of 3 to 4 kcal/mol in adsorption energy for all alcohol molecules, especially emphasized in the Ti-modification in comparison to that of Al-zeolite.

In recent years, hybrid membranes have been developed to address the need for membranes with excellent chemical and thermal resistance. In this study, we present the preparation of a hybrid flat membrane using a dip-coating process with clay and titanium dioxide (TiO2). We investigated two parameters: TiO2 concentration and calcination temperature. We also evaluated the performance of the resulting membranes in treating colored wastewater. Our results show that increasing TiO2 concentration from 1 to 21 g/L enhances the hydrophilicity of the membrane, as evidenced by a decrease in contact angle. The mass of TiO2 fixed on the membrane surface also increases, leading to a similar contact angle for 11 and 21 g/L. Notably, TiO2 nanoparticles were adsorbed onto the membrane pores resulting in reduced membrane porosity. The average permeate fluxes decreased with increasing TiO2 concentration. We also observed a decline in methylene blue degradation rate with the increase of TiO2 concentration from 11 to 21 g/L. The maximum methylene blue degradation rate was achieved with a membrane coated with 11 g/L of TiO2. Moreover, we studied the effect of calcination temperature on membrane properties. Interestingly, increasing the calcination temperature from 300°C to 600°C did not significantly alter the contact angle. The highest methylene blue degradation rate (86.04%) was achieved with 11 g/L TiO2 at a calcination temperature of 300 °C. The prepared flat membranes demonstrated promising performance in treating colored wastewater, highlighting their potential for efficient wastewater treatment applications.

In this research, novel complexes of Zn(II) were produced using amino acid Schiff bases. First, new Schiff bases were synthesized from the reaction of 3-methoxy-2-hydroxybenzaldehyde (o-vanillin) and amino acid methyl esters (isoleucine, phenylalanine, methionine). The synthesis of new complexes was carried out by the reaction of these Schiff bases and Zn(OAc)2.2H2O. The structures of the synthesized complexes were elucidated using elemental analysis, FT-IR, NMR, UV-vis spectroscopy, and thermal analysis techniques. In this research, we synthesized new complexes of Zn(II) with amino acid Schiff bases labeled as 1a-1c. We then examined their impact on specific metabolic enzymes, namely acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). The results showed that the molecules exhibited potent inhibitory activities against all targets compared to the standard inhibitor as indicated by IC50 values. Ki values of the compounds for AChE and BChE enzymes were obtained in the range of 78.04±8.66-111.24±12.61 and 24.31±3.98-85.18±7.05 µM, respectively. Molecular docking calculations were performed to investigate the biological activities of the metal complexes. The Protein Ligand Interaction Profiler (PLIP) was used to study the chemical interactions of metal complexes with enzymes.

The reaction of Lawesson’s reagent (2,4-bis(4-methoxyphenyl)-1,3,2,4-dithiadiphosphetane-2,4-disulfide, LR) with hexamethyleneimine (Azepane), morpholine and diisobutylamine in wet toluene produced [(p-C6H4OMe)2(O)(PS2-)2(C6H12NH2+)2] (I), [(p-C6H4OMe)2(O)(PS2-)2(OC4H8NH2+)2] (II), [(p-C6H4OMe)2(O)(PS2-)2(C8H18NH2+)2] (III), respectively. Compounds I, II, and III are characterized by IR spectroscopy, elemental analysis, 1H, 13C, and 31P NMR techniques. The reaction of compounds with LR produced an ion pair. The X-ray crystallography studies of compound I showed that its asymmetric unit is composed of two independent molecules. In this compound, the P atom is in a tetrahedral environment. Also, the crystal structure of compound I revealed that the P(S)…H–N hydrogen bonds caused the formation of a one-dimensional arrangement. 3D Hirshfeld surfaces (HS) and 2D fingerprint plots (FPs) were used to analyze intramolecular interactions in compound I. The results of the analysis of HS and FPs of compound I demonstrated that H…H interactions had the highest proportions. The antibacterial potential of these compounds was tested against four bacteria, namely Pseudomonas aeruginosa (G-), Escherichia coli (G-), Micrococcus luteus (G+), and Bacillus subtilis (G+).

A facile synthetic route for constructing 2-thioxoquinazolin-4(1H)-one derivative through cyclization reactions using readily available starting materials 2-aminobenzoic acids, alkyl/aryl amines, and carbon disulfide is described. These reactions occur under mild conditions, producing the desired products with good to high yields. Molecular docking was conducted to assess the activities of the 2-thioxoquinazolin-4(1H)-one derivative against breast cancer protein (PDB ID: 1JNX), liver cancer protein (PDB ID: 2H80), and colon cancer protein (PDB ID: 4UYA). Furthermore, an ADME/T analysis was performed to evaluate the impact of these compounds on human metabolism.

In this research, an adiabatic fixed bed reactor is used to determine the reaction kinetics of the heterogeneous decomposition of hydrazine and ammonia with a 15% nickel catalyst based on gamma alumina. This reactor is used in a monopropellant space propulsion system to create a thrust force of up to 10 newtons. The system performs two reactions of heterogeneous decomposition and conversion to light gases of hydrogen and nitrogen at high temperatures. Then, the thrust force is obtained by exiting gases from the nozzle. In this research, the aim is to use nickel catalyst coating instead of iridium (a costly and rare catalyst) based on gamma alumina (with a new combination) and determine the kinetics of heterogeneous decomposition reactions (new research), which is very important in terms of industry and research projects. Also, this research deals with theoretical concepts, kinetic details of heterogeneous decomposition reactions of hydrazine, and ammonia tests necessary to check the catalyst’s performance. To determine the correctness and accuracy of the catalyst performance the kinetic model of heterogeneous decomposition reactions, the kinetic model, and experimental results are checked under the same operating conditions in indicators such as the minimum decomposition amount of hydrazine, ammonia, and thrust force. According to the appropriate matching, the results are confirmed.

The main aim of this study is to introduce a new catalytic system referred to as p(NaAMPS-co-AN)‐[Mn(TMPyP)], which is a combination of poly[(2‐acrylamido-2-methyl-1-propane sulfonic acid-co-acrylonitrile)-Mn(III) meso tetra(N-methyl-4-pyridyl) porphine. The results of the study showed that p(NaAMPS-co-AN)‐[Mn(TMPyP)] exhibited promising catalytic activity for benzyl alcohol (BA) oxidation. Moreover, it demonstrated high selectivity, which is an important factor in a solid-liquid biphasic reaction system. The study conducted a comparison of catalytic activities for BA oxidation. It examined the performance of a reaction-controlled phase transfer catalyst system with two different oxidants.  It's important to consider the choice of oxidants in a biphasic environment to determine their effectiveness in the oxidation process. The p(NaAMPS-co-AN)-[Mn(TMPyP)] catalyst’s macroporous structure not only provides a larger surface area but also facilitates quick diffusion of reactants towards the active Mn(III) centers. This enhanced diffusion can significantly boost the catalytic activity of the catalyst by promoting efficient contact between reactants and catalytic sites. Moreover, the presence of acrylonitrile in the polymer matrix could contribute to the catalyst's stability and reusability, preventing leaching of the active species. This is important for long-term catalytic processes and indicates the potential for sustainable and cost-effective applications. The confirmation of the catalyst's recyclability, durability, and leaching resistance was achieved through various analytical techniques. These methods provide evidence of the catalyst's ability to maintain its structural and functional integrity over multiple cycles of use.  

There is an issue with wide particle size distribution during the suspension copolymerization of styrene-acrylonitrile. This results in a lengthy melting time for larger particles and the formation of undesirable small particles that can conglomerate and deposit in the product transfer line and equipment. Therefore, it is necessary to control the size distribution during production. The effect of different variables like the reaction temperature, final reaction temperature, the mixer speed, the monomer-to-water ratio, the initiator concentration, the chain transfer agent concentration, the proportion of styrene to acrylonitrile, as the suspending agent concentration, the proportion of styrene to acrylonitrile on the monomer conversion, the molecular weight and particle size of the product by Taguchi approach was investigated. As the results showed, the best Particle Size Distribution (PSD) was obtained at the temperature of 76°C and a water/monomer 65/35 (wt/wt), 0.016 suspending agent/monomer (wt/wt), 1000 rpm mixer speed, and 0.0095 (DEM) stabilizer /suspending agent (wt/wt).

This work presents a novel self-healing/anti-corrosion coating based on epoxy resin decorated with electrochemically deposited silicon dioxide (SiO2)/linseed oil (LO). For this purpose, the SiO2/LO composite was prepared via a one-pot electrochemical deposition method, which was then utilized as a precursor for epoxy coating preparation. Various techniques, including Fourier Transform InfraRed (FT-IR) spectroscopy, Scanning Electron Microscopy (SEM), Energy Dispersive X-ray spectroscopy (EDS), ThermoGravimetric Analysis (TGA), and X-Ray Diffraction (XRD) analysis were used to characterize the coated steel samples. Corrosion current and corrosion potential were decreased following the addition of SiO2 and LO to the steel surface. The mechanism of improved anticorrosion performance of the composite coating can be attributed to the synergistic effect of the components within the composite film. The effect of various coatings on the anticorrosive characteristics of the self-healing coatings has been investigated by electrochemical impedance spectroscopy (EIS), Tafel plots, salt spray, and optical images. The defected self-healing coating consisting of epoxy/SiO2/LO exhibited exceptional healing ability and corrosion inhibition performance toward steel metal as evidenced by EIS and optical images. The SiO2/LO coating layer shows the lowest corrosion current of 0.091 µA/cm2 compared to SiO2 with 0.822 µA/cm2 in corrosive saline media. Furthermore, epoxy-coated SiO2/linseed oil and epoxy-coated SiO2 films on steel supports exhibit corrosion resistances of 1.95×108 and 7.20×107 Ω/cm2 demonstrating better performance of silica-containing linseed oil. It seems that the addition of a hydrophobic linseed oil component can successfully delay the diffusion of water molecules or electrolyte ions, resulting in the improvement of anticorrosion characteristics of the coating layer.

Polyallylamine hydrochloride P(AlAm.HCl) is a cationic polymer with many applications because of the existing amines group. Its importance becomes evident as polyvinyl amine polymer cannot be prepared from its monomer via free radical polymerization. Polyvinyl sulfonic acid P(VSA) is an anionic polymer with many applications, such as drug delivery and DNA modification. The synthesis of a new amphiphilic interpolymer complex (IPC) was the aim of the study. Aqueous solutions of P(AlAm.HCl) and P(VSA.Na) were physically mixed in variant repeating unit concentrations that yielded water-insoluble IPCs. FT-IR was used to identify the structures of the IPCs, and TGA was used to determine their thermal properties. XRD patterns were performed to determine the strength of the IPCs. Strong interpolymer complexes were formed in the mole ratio (0.25:1) in feed compositions approved by XRD and TGA. Scanning Electron Microscopy (SEM), micrographs assessed the morphology of the IPC. IPC of deacidified P(AlAm.HCl), and P(VSA) was prepared with different mole ratios of repeating units. These physical IPCs are water-soluble. FT-IR and 1H-NMR were applied to examine the formation of sulfonamide groups and the structural characterization of IPCs between P(AlAm) and P(VSA) at different molar ratios.

A novel approach to address residual oil removal focuses on manipulating the interaction between oil and solid surfaces' interfacial wettability. This innovation offers a fresh perspective to effectively tackle this issue. By transforming rock surfaces into a highly hydrophilic state, substantial enhancements in oil film detachment efficiency can be achieved. However, conventional anionic surfactants can only transition oil-wet rock surfaces to a mildly hydrophilic state. Therefore, the development of innovative surfactants with advanced interfacial wettability control becomes crucial for effective residual oil management. This study introduces the development of a novel polymeric surfactant, AEVF-S. This distinctiveness of AEVF-S lies in incorporating negatively charged polar groups, significantly boosting its adsorption onto oil-wet rock surfaces. This unique feature enhances hydrophilicity in the exposed head groups, resulting in the surfactant's exceptional capability to modify surface wettability. AEVF-S's interaction with submerged oil is particularly noteworthy. This interaction triggers a transformative shift in the surface properties of oil-wet rock, rendering it strongly hydrophilic and oleophobic. The substantial reduction of the contact angle of the oil underwater environment from 147.3° to 99.8° underscores AEVF-S's superiority over most previously reported surfactants. AEVF-S's efficacy extends to oil film removal. Under simulated reservoir conditions, it effectively peels off about 97.3% of the oil film in just 6 hours. Additionally, in dynamic core displacement experiments, AEVF-S enhances the oil recovery ratio by an impressive 21.11% compared to simulated water flooding. These results highlight AEVF-S's potential as a catalyst for efficient residual oil development.

Since natural bitumen without additives is not suitable for creating a robust pavement structure to withstand diverse weather conditions and traffic loads, researchers have been exploring innovative methods to improve and enhance the properties of bitumen in recent years. This paper aims to optimize the composition of modified bitumen, considering the best physical performance for use in hot regions. To achieve this, the influence of four types of additives, namely Recycled Tire Rubber (RTR), Styrene-Butadiene-Styrene (SBS), reused Low-Density PolyEthylene (LDPE), and Sulfur (S), at three levels, is evaluated on the properties of bitumen using the Response Surface Methodology based on Central Composite Design (CCD). Based on the evaluations, optimal values for the additives are determined. Laboratory results demonstrate that the optimal values of the additives not only improve the penetration grade, softening point, ductility, and viscosity of bitumen but also exhibit synergistic effects. Furthermore, the addition of mineral additives significantly enhances the storage stability of the incorporated polymers in bitumen. The optimized modified bitumen, with the aforementioned properties, demonstrates an error value consistently less than 2% of the measured values, providing satisfactory performance for use in hot regions.

Mineral processing plants require a large amount of water; for this reason, maximum water recovery and recycling are essential. One of the most important equipment in the solid-liquid separation process is the thickener. This study investigated the effects of flocculant conditioning on increasing the efficiency of deep cone thickeners of the Sarcheshmeh copper complex. This study aimed to reduce the flocculant consumption and decrease the thickener overflow turbidity by improving the flocculant conditioning. Therefore, in the first step, electrical connections were modified to allow simultaneous use of two flocculant conditioning systems. Then, to increase the filling time of the flocculant mixing tank from 45 to 70 minutes, dry flocculant and water flow rates were decreased. Also the total conditioning time (filling time + mixing time) was increased from 90 to 150 minutes. After the modifications, in addition to increasing the flocculant conditioning time, the flocculant solution concentration decreased from 0.31 to 0.27%. The results showed that dry flocculant lumps (known as fish eyes) in the conditioning tanks were dissolved. Finally, the turbidity of the thickener overflow was improved, and the flocculant consumption was decreased from 32 to 28 g/t. It must be noted that the reduction of 4 g/t of flocculant dosage in the plant saves 120 t/y of dry flocculant.

Fossil fuel consumption and electricity costs are rising daily in developing nations, causing substantial environmental degradation. Finding inexpensive alternative energy sources is crucial given the aforementioned factor. Solar energy generation provides an effective remedy. Many solar applications employ flat plate collectors. In the present experiment, comparisons were made between a flat plate solar collector made of a glass absorber tube that circulates CuO, Al2O3, and ZnO Nanofluids at flow rates of 0,035, 0.045, and 0.065 l/s to evaluate performance and efficiency. The temperature increased as a result of the nanofluids in the absorber tube absorbing more energy than the water might, and the entire apparatus was insulated to reduce heat loss. At noon, when solar radiation reaches 725W, the efficiency of the collector was 58.3% for CuO, 56.4% for Al2O3, 54.3% for ZnO, and 53.3% for water, at a flow rate of 0.035 l/s, and the corresponding to 0.045, 0.055 l/s, had less than the 9.5%,19% respectively. Similarly, the water fluid had a lower value than the Nanofluids.

The current experimental research compares the performances of Solar Still (SS) with and without black-painted clay balls at Erode, India. From the investigations, it was found that an energy storage material augments the evening output. Furthermore, energy and exergy efficiencies of the SS, SS with clay balls, and SS with Black-Painted clay balls (SS with BP-clay balls) were calculated to determine the stills' performance. The distilled water output of 1.95, 2.8, and 3.43 kg was obtained from the SS, SS with clay balls, and SS with BP-clay balls, separately. The calculated energy efficiency of the SS with BP-clay balls is 19.7%, the SS with clay balls is 17%, and the SS is 14%. Also, the exergy efficiency of the SS with BP-clay balls is 1.45%, the SS with clay balls is 1.1%, and the SS is 0.86%. The distilled water output from the SS with BP-clay balls was increased by 43.2% than the SS. Experimentation proved that the use of BP-clay balls improved the performance of the SS during the evening time.

This study aimed to reduce food waste of orange pomace through an improved vacuum dryer with two different normal (NorAtm) and controlled atmosphere (ConAtm) methods. N2 gas was injected into a vacuum chamber to control the drying atmosphere to limit the oxidation reaction. A Central Composite Design (CCD) optimization approach was applied with temperature and pressure levels of 45 to 85 ℃ with an interval of 10 ℃ and 40 to 80 kPa with a 10 kPa interval, respectively, for both drying methods. The parameters, including effective moisture diffusivity, total energy consumption, color indices (ΔL*, Δa*, Δb*, and BI), antioxidant capacity, total phenolic content, and ascorbic acid, were measured for all samples during the drying process. The results showed that the controlled atmosphere positively affected the drying rate (16% increase on average) and could reduce energy consumption (16% decrease on average). Also, in addition to achieving more antioxidant capacity (11% increase), the ascorbic acid was more stable (up to 200%) under the controlled atmosphere conditions. TPC changes were significant at the level of 0.05 just for temperature changes by NorAtm. On the other hand, the effect of vacuum on the Δa* was insignificant for both ConAtm and NorAtm, and the value of Δa* orange pomace dried by ConAtm was lower than NorAtm by about 27%.

The present work deals with the experimental investigation of Hemispherical Solar Still (HSS) using different basin materials with and without Internal Reflector (IR). Three solar stills such us HSS with Steel Basin (HSS-SB), HSS with Zinc Basin (HSS-ZB), and HSS with Copper Basin (HSS-CB) were fabricated. Experiments were conducted with and without IR. It was found that the productivity of the HSS-CB (4.99 kg/m2/day) was better than HSS-ZB (4.26 kg/m2/day) and both of them were better than HSS-SB (3.64 kg/m2/day). Also, it was found that the productivity of the HSS-CB&IR (5.67 kg/m2/day) was better than HSS-ZB&IR (5.04 kg/m2/day), and both of them were better than the HSS-SB&IR (4.28 kg/m2/day). The results revealed that the use of IR improves the yield of HSS from 12 to 15.6%. Also, the thermal and exergy efficiency of the HSS was improved by 14.4 to 20% and 21.1 to 25.4% using IR than without IR. Furthermore, a recovery period and water quality analysis have been carried out. The recovery period of HSS-SB, HSS-ZB, HSS-CB, HSS-SB&IR, HSS-ZB&IR and HSS-CB&IR are 43, 38, 33, 36, 32 and 29 days, respectively.

The wastewater generated by sources like restaurants, garages, etc. contains a high amount of oil and grease content as well as a high Biochemical Oxygen Demand (BOD), which makes its treatment necessary. The traditional existing method of cleaning comes along with its after-effects, which makes the need to find a better alternative necessary. This study aims to examine the adsorptive properties of Raw Coconut Shells in terms of Oil and Grease content, and the BOD reduction of kitchen wastewater. The Oil and Grease content as well as the BOD value of the wastewater pre- and post-passing through the setup with the adsorbent layer are measured and interpreted. The variable parameters in the readings obtained are areas of the tray, the thickness of the adsorbent layer, and the volume of the input sample. The Box Behnken model in the Response Surface Methodology (RSM) is used to generate the parameter combination for the study and the interactive effects of the variable parameters over the target parameter have been studied. From all the trials, the highest reduction in BOD and Oil and Grease content of 94% and 88% respectively was observed with the parameter combinations of 3cm adsorbent layer thickness, 5L sample volume, and 25% area. Further, the maximum percentage of removals has also been predicted from the interactive effects of different parameters. The use of raw coconut shells for adsorption without much modification would reduce the environmental damage that it would otherwise cause as well as a cheaper alternative to making use of a waste product.

COVID-19 significantly impacts the lung's gas exchange units by thickening the gas-blood barrier. This study conducted finite element simulations on a COVID-19 lung-on-a-chip model to assess the impact of alveolar barrier tissue remodeling on blood oxygenation during COVID-19. The results can be used to ensure optimal oxygen treatment and mitigate potential side effects of excessive supplementation. First, the formation of a mucus layer with varying thicknesses was simulated. Interestingly, patients experiencing mucus-induced silent hypoxia did not require oxygen treatment, as their oxygen saturation levels consistently exceeded 90% across all mucus thicknesses. Next, the severe exudative and fibrotic phases of COVID-19, characterized by hyaline membrane and fibrotic tissue, were modeled. Oxygen exchange during these phases sharply declined compared to mucus-induced hypoxia, resulting in blood oxygen levels of 1.2 mol/m3 and 0.96 mol/m3 for 1µm thickness of the hyaline membrane and fibrotic tissue. Furthermore, a five-fold increase in the thickness of the hyaline membrane and fibrotic tissue considerably limited oxygen transfer to about 0.29 mol/m3 and 0.2 mol/m3, respectively. The study also suggested the required alveolar oxygen content for 90% blood saturation in different thicknesses of hyaline membrane and fibrotic tissue. For 1µm thickness of the hyaline membrane and fibrotic tissue, the alveolar oxygen content needed to be 16.45% and 20.39%, respectively. The required oxygen increased to 68.42% and 98.68% for 5µm thickness of the hyaline membrane and fibrotic tissue, respectively. Moreover, the investigation showed that changes in blood viscosity, flow rate, and hemoglobin concentration had minimal impact on blood oxygenation during COVID-19 disease. In conclusion, this study provides valuable insights into how alterations in the air-blood barrier and blood disorders in COVID-19 disease affect gas exchange dynamics. It also suggests oxygen treatment requirements for each phase of COVID-19 disease, which can optimize oxygen therapy and improve patient care.

This study successfully synthesized a magnetic chitosan biopolymer covalently grafted onto acetamido tetrazole and evaluated it as a high-potential biocompatible non-viruses vector. The synthesized nanocarrier was fully characterized by FT-IR spectra, TEM and FESEM images, XRD, EDX, FESEM, and DLS analyses. The loading capacity of the plasmid was optimized with the ratio N/P 3 with excellent protection of the plasmid. The nanocarrier showed high gene expression and transfection in the HECK-293T cell line without any inherent toxicity. In addition, experimental results show that the new functionalized chitosan has excellent DNA condensation, protection, and high target transfection efficiency. Therefore, the novel magnetic chitosan nanocarrier functionalized with acetamido tetrazole has shown potential uses in cancer therapy.

Chlorophyll a and phycobiliproteins are ubiquitous cyanobacterial secondary products of vast scientific and technological interest and their accurate measurement is necessary in many application fields. In this work, three different cell disruption methods of freeze-thawing, ball milling, and ultrasonication were extensively investigated for the extraction and spectrophotometric determination of Chlorophyll a and phycobiliproteins from the filamentous cyanobacterium Anabaena flos-aquae. By studying the effect of the duration of the last two treatments, a total of five different procedures were explored. While all methods were found to return statistically equivalent results for Chlorophyll a under the test conditions (4.078±0.256 to 4.706±0.201 µg/mL), ultrasonication and ball milling for longer durations outperformed others for phycobiliproteins extraction (with phycocyanin concentrations of 19.485 and 19.557 µg/mL, respectively). In addition, the interference of the overlapping Chlorophyll a peak during the phycobiliproteins quantification was analyzed and ultrasonication for extended duration was shown to offer not only a reasonably high yield but a low Chlorophyll a interference as well. Furthermore, common equation sets for the calculation of phycobiliprotein concentration from the spectral data were compared and potential discrepancies were highlighted. This study is believed to provide insights for future research regarding the extraction and spectrophotometric determination of cyanobacterial pigments.

Bone damage due to internal or external factors is one of the most common diseases of today's societies in the field of orthopedics, one of the common treatments to solve it is the use of artificial bone graft substitutes made by the usual methods of freeze-drying. The method of making three-dimensional porous scaffolds, which has the potential to be used as an alternative to bone grafting using the freeze-drying method, is strongly felt by researchers. The use of new nanoparticles such as zirconium in the polymer network creates a porous scaffold. In this research, scaffolds were first prepared by freeze-drying with a structure and topology close to the bone, then the scaffold was placed in polymers with a weight percentage of 1% of different materials and placed in a freeze-drying machine. The use of zirconium nanoparticles has been incorporated as an auxiliary element for the construction of bionanocomposite porous bone scaffolds. Scanning electron microscope (SEM) was used to examine the structure, X-Ray Diffraction (XRD) was used to examine the phasology, and mechanical and biological tests were used to describe the fabricated scaffolds. As a result of the construction of these scaffolds, it was found that these scaffolds show controlled and interconnected porous structures that the size of the pores and porosity of the scaffolds can be effectively adjusted by choosing appropriate amounts of polymer and nanoparticles. The results obtained from the measurement of mechanical properties showed that the scaffolds can basically maintain their strength in their dry state and are close to cancellous and even cortical bones in terms of mechanical properties. The swelling behavior of the scaffolds was also investigated in the body-simulating solution. The cytotoxicity of the scaffold was investigated by direct measurement for three days, and the result of the sample containing zirconium and drug (HA/SA/Cs/CaP/A/Zr) was significantly better than other samples. In the end, this research shows that bionanocomposite scaffolds are a suitable and desirable option for bone tissue engineering.

The field of Additive Manufacturing (AM), also known as 3D printing, has experienced rapid advancements, revolutionizing traditional approaches to object design and production. This innovative process entails the layer-by-layer deposition of materials in three-dimensional coordinates based on digital files. Additive manufacturing has gained widespread adoption across diverse sectors such as aerospace, robotics, education, medicine, pharmaceuticals, automotive, and construction. Among the techniques employed in AM, the powder bed fusion process is commonly used, including methods like Direct Metal Laser Sintering (DMLS), Electron Beam Melting (EBM), Selective Thermal Sintering (STS), Selective Laser Melting (SLM), and Selective Laser Sintering (SLS). The SLS 3D printer, as a powder bed fusion technique, has undergone multiple modifications to enhance precision and reduce operational expenses. By utilizing a high-power laser, the SLS 3D printer selectively fuses or sinters powdered materials, typically polymers or metals, to fabricate three-dimensional objects. The printer bed is heated to just below the material's melting point, and the laser precisely targets specific areas based on the digital design file. As the laser heats the powder particles, they fuse together, forming a solid layer. This layer-by-layer process continues until the 3D object is fully realized. The SLS 3D printer has found practical applications in sectors such as aerospace, medicine, and pharmaceuticals. In the aerospace industry, it is employed to manufacture lightweight components featuring intricate geometries. The medical field benefits from the SLS 3D printer's ability to produce customized and precise implants and prosthetics. Additionally, the pharmaceutical industry utilizes this technology for the creation of drug delivery systems with controlled-release properties. The SLS 3D printer has undergone significant advancements as a powder bed fusion method, allowing for the production of highly precise and customized items with complex geometries. Improvements have been implemented to enhance accuracy and reduce operational expenses. Its versatility makes it suitable for diverse industries.