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From long ago, orthopedists and physicians are trying to deal with bone diseases and disorders, while today, in the regenerative medicine field, bone scaffolds are being in attendance. Although there were common methods for fabricating bone scaffolds, such as foam casting and gas foaming, additive manufacturing (AM) techniques have been considered for producing bone scaffolds due to some appealing features such as creating a hierarchical structure, regular and controlled porosity, and designing of the complicated structures. AM techniques are divided into three categories, including extrusion-based, powder-based, and vat polymerization (light-based) techniques. Among the AM methods, the robocasting technique as an extrusion-based method is highly regarded for designing high-strength scaffolds for bone tissue regeneration owing to special features, for instance, a low-volume binder and the ability to print all types of ceramic materials as well as metals and polymers. This study discusses the robocasting method, as well as the essential parameters that are involved in 3D printing of the ideal scaffold with this method, such as the material, the structure of the robotic device, the printing parameters, the properties of the ideal paste or ink, the role of binder and its types in robocasting, and the rheological properties required in robocasting method. Also, future prospects and clinical applications of this technique were reviewed.

This study aims at investigating the effect of the substrate material on growth mechanism and also microstructure of Ta2O5 thin films. For this purpose, atomic force microscopy, scanning electron microscopy, and interferometry analyses were implemented to reveal the influence of silicon wafer and amorphous BK7 glass substrates on the nucleation and growth mechanisms of Ta2O5 thin films deposited via the radio frequency magnetron sputtering technique. Results indicated that those films with finer morphologies had relatively higher nucleation densities. Compared with BK7 glass substrate, crystals formed on the silicon wafer were shown to be finer and had lower mean areas in more nucleation sites. Moreover, optical properties and morphological characteristics of the films on the silicon substrates had much more endurance after the annealing treatment. It was observed that shift in the transmission spectra of the deposited films after the treatment was insignificant, implying high packing density of the films. However, a 6-nm shift in the transmission spectra indicated low density and high porosity of the films. Finally, atomic force microscopy analysis along with the light scattering measurements confirmed the formation of a low-roughness film on the silicon wafer substrates.

Porous burner offers attractive advantages including high combustion performance and power ranges, and approximately zero pollutant emission. In this paper, the thermal behavior of premixed flame o...

The purpose of the present work is to investigate the effect of the angle of application of magnetic field in two types of uniform and non-uniform on the nanofluid flow characteristics and natural convection heat transfer in the presence of uniform heat generation. This numerical study was performed using multi relaxation time lattice Boltzmann method (MRT-LBM). The D2Q9 and D2Q5 grid arrangements were used to simulate the flow and temperature fields, respectively. The results show that in all cases, increasing the strength of magnetic field (the Hartmann number) reduces the average Nusselt number, which increases with increasing the heat generation coefficient. Applying a magnetic field horizontally results in an average of about 15% lower Nusselt number compared to the vertical. Increasing the strength of magnetic field (the Hartmann number) and the average Nusselt number is achieved by periodically applying a magnetic field instead of applying a uniform one. As the aspect ratio of the cavity increases, the non-uniform effect of applying a magnetic field becomes more apparent.

The low mechanical properties of polybutylene succinate (PBS) limit its applications in the preparation of biodegradable filtration membranes. In this work, acrylonitrile butadiene styrene (ABS) was used to improve the mechanical properties of filtration membranes for the first time. Polybutylene succinate (PBS)/acrylonitrile butadiene styrene (ABS) blends containing 10, 20, and 30 wt% ABS were prepared by dissolving in N-methyl-2-pyrrolidone (NMP), and then membranes were prepared through immersion precipitation. Surface and cross-sectional scanning electron microscopy (SEM), porosity measurement, Fourier transform infrared spectroscopy (FTIR), water contact angle and water content measurements, tensile test, and thermogravimetric analysis (TGA) were conducted to characterize the membranes. Filtration experiments were performed to treat fruit juice production wastewater to determine the rejection of turbidity and chemical oxygen demand (COD). Also, the membrane tendency to fouling was assessed. The results of mechanical properties showed that with increasing the amount of ABS, the mechanical properties of the samples improved so that by increasing the ABS loading to 10, 20, and 30 wt%, the tensile strength increased by 44%, 131%, and 188%, and the elastic modulus increased by 17%, 78%, and 99%, respectively, compared to the mechanical properties of pure PBS. The blend membranes had less tendency to irreversible fouling than the neat PBS membrane regarding the filtration results. The results of wastewater filtration indicate that the COD rejection dropped and steady permeate flux raised with increasing ABS amount. All the membranes rejected 100% of turbidity and thus can be utilized in wastewater pretreatment.

Free convection heat transfer over annular finned tubes was studied numerically for more than sixty different cases and verified against two experimental works. In addition, the effect of fin spaci...

In this work, the two dimensional transition of H2-O2 deflagration-to-detonation was examined in some porous closed-ducts by an in-house high speed reacting flow solver in OpenFoam package—a pressu...

Nanocomposites and nanomaterials have frequently useful advantages for drug delivery applications because of their excellent potential in cancer therapy. This study development of nanocomposites from graphene/N-phthaloylchitosan –graft- poly(methylmethacrylate-block-(poly ethylenglycol methacrylate -random-dimethylaminoethyl methacrylate), CS-g-P(MMA-b-(PEGMA-ran-DMAEMA), via reversible addition fragmentation chain transfer polymerization. The structure of the copolymer and nanocomposite were investigated by FT-IR and 1HNMR. The nanocomposites properties of GO/ CS-g-P(MMA-b-(PEGMA-ran-DMAEMA) were investigated by scanning electron microscopy (FE-SEM), dynamic light scattering, ultraviolet–visible (UV–Vis) spectroscopies, and thermogravimetry measurements. We developed a biodegradable GO nanocomposites to overcome limitations of doxorubicin (DOX)-loading. The drug loading efficiency of GO/nanocomposites for DOX was high, and 81% efficiency was obtained. Release behavior of DOX from the nanocomposites showed that the rate of DOX release is controlled by pH values.

The heat transfer coefficient, pressure drop, and vertical segregation in a bubbling fluidized bed reactor containing random packings were investigated. The bed material was silica sand in the size range of 90−400 μm. Experiments were done for bed temperatures ranging from 400 to 900 °C and superficial gas velocities up to 0.411 m/s. Five different types of packings were evaluated: (i) RMSR (25 mm stainless steel thread saddle ring), (ii) Hiflow (25 mm stainless steel pall ring), (iii) RR6 (6 mm ceramic Raschig ring), (iv) RR10 (10 mm ceramic Raschig ring), and (v) ASB (12.7 mm aluminum silicate balls). The RMSR packing showed an increase in the heat transfer coefficient (up to 1243 W/m2 K), as compared to bubbling beds with no packings (up to 1124 W/m2 K). Also, beds with RMSR and Hiflow packings had a lower pressure drop and vertical segregation compared to low void factor packings such as RR6, RR10, and ASB.

This study aimed to assess the effect of Er,Cr:YSGG laser on microtensile bond strength of composite to dentin using two different bonding systems. Sixty teeth were initially collected; out of which, 48 met the inclusion criteria for enrollment. They were randomly divided into 4 groups (n = 12). The dentin surface in groups 1 and 3 was prepared with fissure diamond bur, while groups 2 and 4 were irradiated by Er,Cr:YSGG laser. Clearfil SE Bond self-etching adhesive and All-Bond Universal adhesive were applied on the prepared dentin surfaces. Composite blocks were then bonded to dentin surfaces. The samples were thermocycled for 10,000 cycles between 5 and 55 °C. They were then mounted in acrylic resin and sectioned longitudinally to form dentinal slabs bonded to composite. Samples were stretched at a speed of 0.5 mm/min in a microtensile tester until failure. Data were analyzed using ANOVA and a post hoc test. The maximum bond strength was noted in the bur preparation plus Clearfil SE Bond group. The minimum strength was noted in the bur preparation plus All-Bond Universal group. There was no significant difference between the two methods of dentin surface preparation. Clearfil SE Bond yielded higher microtensile bond strength than All-Bond Universal. Clinical significance Considering the introduction of new modalities for cavity preparation such as dental lasers according to the goals of minimally invasive dentistry and the importance of direct composite restorations due to their optimal esthetics, evaluation of tensile bond strength of composite to laser-treated dentin seems to be a research priority.

The main bottleneck for implementing magnetic nanowires (MNWs) in cell-biology research for multimodal therapeutics is the inapplicability of the current state of the art for selective detection and stimulation of MNWs. Here, we introduce a methodology for selective detection of MNWs in platforms that have multiple magnetic signals, such as future multimodal therapeutics. After characterizing the signatures of MNWs, MNWs were surface-functionalized and internalized into canine osteosarcoma (OSCA-8) cancer cells for cell labeling, manipulation, and separation. We also prepared and characterized magnetic biopolymers as multimodal platforms for future use in controlling the movement, growth, and division of cancer cells. First, it is important to have methods for distinguishing the magnetic signature of the biopolymer from the magnetically labeled cells. For this purpose, we use the projection method to selectively detect and demultiplex the magnetic signatures of MNWs inside cells from those inside magnetic biopolymers. We show that tailoring the irreversible switching field of MNWs by tuning their coercivity is a highly effective approach for generating distinct magnetic biolabels for selective detection of cancer cells. These findings open up new possibilities for selective stimulation of MNWs in multimodal therapeutic platforms for drug delivery, hyperthermia cancer therapy, and mitigating cancer cell movement and proliferation.

In the present study, we introduce mesoporous g-C3N4/Ag co-doped with P and S which was designed and acquired by using mesoporous silica (SBA-15) as a hard templating agent and thiourea and chitosan phosphate as the dopants. The prepared catalyst was completely identified by FT-IR (Fourier-transform infrared spectroscopy), XRD (X-ray powder diffraction), FE-SEM (field-emission scanning electron microscopy), EDX (energy-dispersive spectroscopy), TEM (transmission electron microscopy), and Raman spectroscopy. The efficiency of the synthesized catalyst was evaluated toward the three-component coupling reaction, frequently named as A3 coupling. The higher activity of the prepared catalyst is because of the synergistic effects of phosphorus and sulfur co-doped together with Ag deposition. The desired products were achieved by an environmentally safe catalyst under the optimized conditions in high yields and short reaction time ranges.

In this work, a new carboxylate-modified pine cone is synthesized via esterification of pine cone with isopropylidene malonate. The chemical modification procedure is optimized, and then, the adsorbent prepared is characterized by different techniques such as field emission scanning electron microscopy, energy-dispersive X-ray diffraction, and FT-IR spectroscopy in order to approve the presence of carboxylic groups on the surface of pine cone. The performance of the bio-sorbent is investigated for the removal of lead ions from the aqueous solution. The factors affecting the performance of the prepared adsorbent are analyzed and optimized in an experimental setup. Under the optimum conditions, studying the experimental data illustrates that the Langmuir isotherm can suitably describe the equilibrium data, and at a temperature of 298 K, pH 4.8, and 0.40 g L−1 of the adsorbent, the maximum adsorption capacity of 400.0 mg g−1 is obtained; this value is much higher than some of the newly reported ones. The high lead ion adsorption can be attributed to the abundant functional groups present in the adsorbent. Carboxylate-modified pine cone can be successfully regenerated for 3 times using EDTA-2Na as the solvent elution.

Nematic liquid crystals of achiral molecules or racemic mixtures of chiral ones form flat films when suspended in submillimeter size grids and submerged under water. Recently, it has been shown (Popov et al., 2017) that films of nematic liquid crystals doped with chiral molecules adopt biconvex lens shapes underwater. The curved shape together with degenerate planar anchoring leads to a radial variation of the optical axis along the plane of the film, providing a Pancharatnam-Berry-type phase lens that modifies geometric optical imaging. Here, we describe nematic liquid crystal microlenses formed by the addition of chiral nanoparticles. It is found that the helical twisting power of the nanoparticles, the key factor to form the lens, is about 400 μm

Chirality of nanomaterials is a rapidly evolving field, largely driven by the unique optical, electronic, magnetic or catalytic properties of plasmonic, magnetic and semiconductor nanomaterials amo...

A new amorphous carbon-based dispersive micro solid-phase extraction method was developed for the extraction and preconcentration of several mycotoxins from soymilk samples. The extracted analytes were concentrated by a deep eutectic solvent-based dispersive liquid–liquid microextraction method, and then, quantified by a high-performance liquid chromatography-fluorescence detector. The sorbent was prepared from β-cyclodextrin and methionine under mild conditions. The sorbent was doped by N and S, which improved its physicochemical properties. The optimization and validation of the method were performed using the “one-variable-at-a-time” method and International Council Harmonization guideline, respectively. Under the optimal conditions, low limits of detection and quantifications in the ranges of 0.08–0.56 and 0.27–1.9 ng L−1 were obtained, respectively. Also, intra- (n = 6) and inter-day (n = 6) precisions showed an acceptable repeatability of the present work as they were in the ranges of 3.9–6.2 and 4.6–8.9% at a concentration of 3 ng L−1 of each analyte, respectively. Finally, the proposed method was performed on different soymilk samples marketed in Tabriz city, and aflatoxin B1 was found in all samples. One soymilk was contaminated by ochratoxin A.

The influence of loading type on tensile and tearing fracture resistance of ballast rock was assessed using edge-notched diametrically compressed disc (ENDC) and edge-notched disc bend (ENDB) test geometries. The geometry of these two specimens was similar; however, their loading type (i.e., three-point bend and diametral compressive) was different affecting the geometry factors. The obtained pure tensile fracture toughness (KIc) using the ENDB test was higher than the ENDC test. In contrast to tensile fracture toughness, the pure tearing fracture toughness (KIIIc) in the ENDC test was higher than the ENDB fracture test. The obtained experimental data were explained in terms of crack propagation path, since two distinct trajectories were observed for both configurations under tearing deformation.

Background: Aflatoxin B1 is a secondary toxic metabolite produced by several aspergillus species. This study was conducted to determine the presence of aflatoxin in tomato paste samples. Methods: A total of 30 tomato pastes were analyzed for Aflatoxin B1 contamination via HPLC-FLD. Analyte extraction was done by dispersive liquid-liquid microextraction. Results: The limit of detection (LOD) and limit of quantitation (LOQ) were 0.14 and 0.44 µg/kg, respectively. The recovery rates ranged from 91 to 94%. The findings showed all samples were contaminated with Aflatoxin B1 and the average concentration was 1.1 ± 0.02 µg/kg. The amount of aflatoxin B1 in 6 samples was higher than the limit set by the European Union. Conclusion: The proposed method was successfully applied to the analysis of tomato paste samples with quantitative results. The main advantages of the developed method include its simplicity in operation, rapid achievement of a very high sample, and low cost.

Conductive self -electrical stimuli bioactive scaffolds could be used the potential for peripheral nerve regeneration with the maximum efficiency. To produce such conductive self-electrical stimuli bioactive scaffolds, chopped spun piezoelectric nanofibers of polyvinylidene fluoride/mesoporous silica nanoparticle (PVDF/MCM41) are prepared and incorporated in gellan/polyaniline/graphene (gellan/PAG) nanocomposites which have been previously prepared by incorporation of polyaniline/graphene (PAG) nanoparticles in gellan gel at 80 °C. Highly conductive binary doped polyaniline/graphene nanoparticles are prepared by chemical oxidative polymerization of aniline monomer using in-suite precipitation polymerization method in presence of graphene nanoparticles and sodium dodecyl sulfate. All intermediate and final products including spun PVDF/MCM41 nanofibers, PAG nanoparticles, and gellan-gelatin gel scaffolds containing PVDF/MCM41 nano spun fibers and PAG nanoparticles are characterized using different analysis methods. Chemical and structural analyses of PAG nanoparticles and PVDF/MCM41 nanofibers have been done using FTIR and XRD methods. The morphological structure of different samples is investigated using SEM. Morphological investigation and DLS results confirm fabrication of MCM41 nanoparticle with a completely spherical shape and the average size of 50 nm of which have been dispersed in electrospun PVDF nanofibers very well. Also, the preparation of PAG nanoparticle with high conductivity is verified with morphological and conductivity tests. MTT easy and biocompatibility test results indicate potential applicability of the prepared conductive self -stimuli nano-scaffold for nerve regeneration applications.

The present study demonstrated the incorporation of functionalized nanodiamonds (NDs) in polyurethane (PU) with various loadings (0.1, 0.25, 0.5, 0.75, and 1.0 wt%) to fabricate mixed matrix membranes (MMMs) with an upgraded capability of capturing CO2. An appropriate molar ratio of polyol:diisocyanate:chain extender (1:3:2) was used to synthesize all polymers. The MMMs were fabricated using the solution blending and casting method. The transmission electron microscopy results demonstrated that the silanized nanodiamond (SND) had less aggregation and a higher dispersity than the carboxylated nanodiamond. Also, by adding –NCO functional groups to the SND nanoparticles, their aggregation was minimized while the dispersity was improved. Moreover, characterization of the functionalized NDs was carried out by Fourier-transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). The distribution of functionalized NDs throughout the PU matrix was confirmed by Field-emission scanning electron microscopy (FE-SEM). Also, the crystallinity of all the membranes was examined by XRD and differential scanning calorimetry; besides, we used FTIR to examine phase separation between soft and hard segments. Permeation tests of CO2, N2, and CH4 were performed on all membranes in order to examine CO2 separation performance. According to the gas permeability results, among all samples, PU/SND-NCO with 0.5 wt% SND-NCO showed the highest separation performance due to the better dispersion and interfacial interaction of fillers through the polymer matrix compared to other samples, as FE-SEM suggested earlier. Indeed, increasing SND-NCO up to 0.5 wt% caused an increment of 41.6, 37.0, and 53.6% for CO2 permeability, CO2/N2 selectivity, and CO2/CH4 selectivity, respectively, in comparison with the pure PU membrane.

Computation-ready metal–organic framework (MOF) databases (DBs) have tremendous value since they provide directly useable crystal structures for molecular simulations. The currently available two DBs, the CoRE DB (computation-ready, experimental MOF database) and CSDSS DB (Cambridge Structural Database non-disordered MOF subset) have been widely used in high-throughput molecular simulations. These DBs were constructed using different methods for collecting MOFs, removing bound and unbound solvents, treating charge balancing ions, missing hydrogens and disordered atoms of MOFs. As a result of these methodological differences, some MOFs were reported under the same name but with different structural features in the two DBs. In this work, we first identified 3490 common MOFs of CoRE and CSDSS DBs and then performed molecular simulations to compute their CH4 and H2 uptakes. We found that 387 MOFs result in different gas uptakes depending on from which DB their structures were taken and we identified them as ‘problematic’ MOFs. CH4/H2 mixture adsorption simulations showed that adsorbent performances of problematic MOFs, such as selectivity and regenerability, also significantly change depending on the DB used and lead to large variations in the ranking of materials and identification of the top MOFs. Possible reasons of different structure modifications made by the two DBs were investigated in detail for problematic MOFs. We described five main cases to categorize the problematic MOFs and discussed what types of different modifications were performed by the two DBs in terms of removal of unbound and bound solvents, treatment of missing hydrogen atoms, charge balancing ions etc. with several examples in each case. With this categorization, we aimed to direct researchers to computation-ready MOFs that are the most consistent with their experimentally reported structures. We also provided the new computation-ready structures for 54 MOFs for which the correct structures were missing in both DBs. This extensive comparative analysis of the two DBs will clearly show how and why the DBs differently modified the same MOFs and guide the users to choose either of the computation-ready MOFs from the two DBs depending on their purpose of molecular simulations., European Union (EU); H2020; European Research Council (ERC)-2017-Starting Grant; COSMOS

The transformation of gibbsite to α-alumina occurs in the range 1100 to 1300°C. The higher the calcination temperature, the larger the crystallites and this leads to abnormal grain growth. The main...

The purpose of this study was to remove lead and arsenic ions from aqueous solutions using the activated carbon prepared from Citrus limon tree leaves. Characteristics of the prepared adsorbent were studied thoroughly using BET, SEM, EDS and mapping, XRD, and RAMAN analyses. The results of experiments showed that the highest adsorption efficiencies were 97.67% and 95.89% for Pb (II) and As (III), respectively. Additionally, the adsorbent was successfully regenerated four times and therefore it was able to perform the adsorption and desorption processes well. Moreover, the results of adsorption kinetics showed that the pseudo second-order kinetic model was more effective for the description of adsorption mechanism of both metals. Furthermore, the equilibrium studies indicated that Langmuir and Freundlich isotherm models were desirable for lead and arsenic ions, respectively.

Combination of counter current salting-out homogenous liquid–liquid extraction and deep eutectic solvent–based hollow fibre protected preconcentration method has been developed for the extraction of some antibiotics from propolis samples prior to their determination by ion mobility spectrometry. In this method, an appropriate amount of the powdered propolis is mixed with iso-propanol and deionised water to obtain a homogenous solution. Then, this solution is passed through a glass tube filled with sodium chloride. By this action, the fine droplets of iso-propanol are released and the analytes are extracted into them. The separated iso-propanol is taken and slowly entered into a hollow fibre. By doing so, the analytes are trapped in the pores of hollow fibre and the organic solvent is evaporated after a few minutes. After that, a few microlitres of a water-miscible deep eutectic solvent (prepared from N,N–dimethyl ammonium chloride and propionic acid) is added to elute the analytes from the pores of hollow fibre. Method validation studies indicated that the introduced method has low limits of detection (0.27–0.41 ng g–1) and quantification (0.91–1.37 ng g–1), high enrichment factors (562 –603) and extraction recoveries (84–90%), acceptable repeatability (relative standard deviation ≤ 9.2%) under the optimum conditions. Abbreviations: CCSHLLE: Counter current salting-–out homogenous liquid–liquid extraction; DES: Deep eutectic solvent; EF: Enrichment factor; ER: Extraction recovery; HBA: Hydrogen bond acceptor; HBD: Hydrogen bond donor; HF–LPME: Hollow fiber–liquid-phase microextraction; HPLC: High-performance liquid chromatography; IMS: Ion mobility spectrometry; LOD: Limit of detection; LOQ: Limit of quantification; LR: Linear range; RSD: Relative standard deviation.

Ceramic-magnetic nanoparticles (CMNPs) are attracting attention due to their various applications, especially in biomedical industries. Among them, spinel ferrite CMNPs have received considerable deliberations among different spinel metal oxides due to their fascinating characteristics. Spinel ferrite CMNPs are used for enhancement of the applicability of CMNPs without affecting the intrinsic advantages of iron oxide CMNPs. Spinel ferrites with doping agents have useful electrical and magnetic properties in various fields. Moreover, the replacement of metallic atoms in ferrites is promising to manipulate physical characteristics and improve their performance. Among different spinel ferrites, CoFe2O4 nanoparticles are the most investigated CMNPs. Furthermore, they are used as permanent magnets, magnetic recorders in high-density and micro-wave devices, and magnetic fluids. This study reviews the CoFe2O4 nanoparticles doped with various elements and their applications in various fields.

In this study, thermo-fluid characteristics of elliptical annular finned tube heat exchanger were numerically studied in detail. Transition SST model was utilized to simulate turbulent flow. Effects of air velocities, horizontal to vertical fin diameter ratios, and fin densities were examined in detail. The simulations indicate superior performance of elliptical fin layout. It was shown that pressure drop of annular elliptical fin can be only one half of that of a circular annular fin while containing comparable heat transfer performance. The vertical elliptical annular fin may even contain a higher heat transfer performance over circular fin. Correlations are proposed to estimate the Nu number and pressure drop based on the annular circular fin. The maximum deviations between the proposed correlations and simulations regarding pressure drop and heat transfer coefficient are 5.6% and 3.2%, respectively. For further elaboration of the superiority of the elliptical layout from the second law perspective, normalized entropy generation was also studied. In all cases, the entropy generation rate in circular fin was higher than that of an elliptical fin.

The reduced graphene oxide-Fe2O3 (rGO-Fe2O3) nanocomposites were synthesized by a facile and low-cost hydrothermal method employing rGO and Iron (III) nitrate precursors. The synthesis parameters including the reduction time and presence of reduction aid are studied. The structural and morphological studies of the nanocomposites were investigated by using Raman spectra, Fourier transform infrared spectroscopy, X-ray diffraction, and field emission scanning electron microscopy. The results indicate that Fe2O3 nanoparticles with average particle size of 25 nm are well anchored on graphene sheets and the weight percent of the nanoparticles in the nanocomposites was influenced by the reduction time. The as-synthesized nanocomposites were characterized by a three-electrode system using cyclic voltammetry, electrochemical impedance spectroscopy, and galvanostatic charge–discharge in 1 M KOH aqueous solution. The electrodes made of rGO-Fe2O3 nanocomposite synthesized by urea as reduction aid showed a high specific capacitance of 291 F g−1 at 1 A g−1 in the potential range of − 1 to 0 V. The best electrochemical performance of urea reducted rGO-Fe2O3 nanocomposites is basically attributed to the effect of Fe2O3 nanoparticles in preventing the restacking of rGO sheets.

To widely commercialize electric vehicles (EVs), more efforts to improve their life span seem profoundly inevitable. Thermal conditions have profound the nonlinear effects on the degradation rate, performance, and safety level of an EV battery pack. In the current study, both cycle life and calendar life of a commercial LiFePO4-based cell are investigated experimentally via electrochemical impedance spectroscopy (EIS) for different operating temperatures. This is the first time that the effects of low temperatures such as − 20 °C and − 5 °C on the life of LiFePO4-based cells are investigated via EIS, which is the crucial case during the cold start of EVs in cold climate regions of the world. The results show a considerable increase of solvent resistance for the cell which experienced calendar aging test at 55 °C; this demonstrates a drastic thickening of the SEI for this storage temperature. Moreover, anode cracking is clearly observed at such a high temperature. The results of the cycle aging tests also show that the increase in the solvent resistance is negligible for all other three operating temperatures. Nevertheless, the increasing of SEI thickness at low-temperature condition (− 5 °C) is noticeable. The role of temperature on the degradation level of LiFePO4-based cells has also been discovered via scanning electron microscopy.

Molecular machines and surface rolling molecules show great potential to accomplish different tasks in several fields, such as bottom-up assembly and nano-manipulation. Many researchers have invest...

In this study, miscible viscous fingering instability is examined numerically by using the two-phase Darcy’s law and transport equations. The effects of the viscosity ratio, anisotropic permeability, and porosity on instabilities are investigated. The finger patterns and their splitting and spreading in the domain are discussed. An image processing algorithm is applied to concentration contours to quantify instability parameters, such as the breakthrough time, efficiency, and fractal dimension. It is revealed that more complex fingers are obtained as the viscosity ratio increases, while the efficiency and the breakthrough time decrease. It is demonstrated that high permeability perpendicular to the flow direction leads to instability intensification and to an increase in the fractal dimension, whereas changing the porosity does not have any considerable impact on viscous fingering instability.

In the present work, a model was proposed to simulate the growth in an industrial multi-chamber fluidized bed granulator under steady-state condition. To simulate the growth, it was assumed the coating is the only growth mechanism. Mass balance, as well as particle number balance (PNB), was considered in the simulation. Despite previous works, it was not assumed that particles in each chamber are at the same age. Consequently, the growth was simulated along the granulator length, from its beginning to the end. In this model, most of the influencing parameters are collected in one parameter called C1. Using finite difference method, equations were solved and results were compared with samples from an industrial granulator and very good agreements were observed. Sensitivity of the product normalized mass density function to the parameter C1 was also studied. It was found that for a specific inlet seeds diameter distribution, d50 of the product is not a linear function of C1.

In the present work, a counter current salting-out homogenous liquid–liquid extraction combined with deep eutectic solvent-based–solidification of floating organic droplet-dispersive liquid–liquid ...

In the present study, a stir bar sorptive extraction (SBSE) method coupled with deep eutectic solvent (DES)-based dispersive liquid–liquid microextraction (DLLME) has been developed for the simultaneous derivatisation and extraction of some acidic pesticides before their analysis by gas chromatography-mass spectrometry (GC-MS). In this method, initially, the analytes are adsorbed on a coated stir bar from an aqueous solution. Then, the stir bar is removed and a water-miscible DES is used to elute the analytes. Afterwards, butyl chloroformate (BCF) and a water-immiscible DES are added to the obtained elute as a derivatisation agent and an extraction solvent, respectively. In this work, the use of common toxic organic solvents is omitted, and for the first time, DESs are used as elution (for desorption of the analytes from stir bar), disperser and extraction solvents. Under the optimum conditions, the introduced method indicated high enhancement factor (EnF) (1743–3654), enrichment factor (EF) (1232–1532), and extraction recovery (ER) (74–92%), low limit of detection (LOD) (14–29 ng L–1) and limit of quantification (LOQ) (47–98 ng L–1), good linearity (r2 ≥ 0.9969) and satisfactory repeatabilities. Finally, the proposed method was applied in the analysis of the analytes in various fruit juice samples.

In the present work, G-TiO2 and G-ODA-TiO2 hybrids were prepared by concurrent surface functionalization and reducing of graphene oxide (GO) using octadecylamine (ODA). The G-TiO2 and G-ODA-TiO2 powders were deposited on the copper surface by electrophoretic deposition (EPD) technique. The wettability of coatings revealed the preferable hydrophobic characteristic of G-ODA-TiO2 compared to G-TiO2 and bare copper with water contact angles of 130°, 101°, and 87°, respectively. The anti-corrosion performance of specimens in a 0.5 M H2SO4 solution was appraised by the potentiodynamic polarization (Tafel analysis), which clearly showed that G-TiO2 and G-ODA-TiO2 coatings can act as a great barrier for copper in the corrosive H2SO4 solution. The corrosion inhibition of G-TiO2 and G-ODA-TiO2 was about 2 and 15 times higher than bare copper. Moreover, the hydrophobic G-ODA-TiO2 coating on copper reached a much lower interfacial contact resistance (ICR) than the other samples.

In this study, we examined the catalytic role of low rhodium embedded onto MOF-5 as a hard template, in the ring opening reaction of epoxides with N3− anion as nucleophile. The material was characterized by SEM, TEM, FT-IR, XRD, EDAX, BET, H2-TPR, and AAS techniques. Furthermore, we used BBD and RSM to obtain the optimum reaction conditions, which was 2.25% of Rh loading, 0.05 g amount of the catalyst, and 60 min reaction time at a temperature of 45 °C. The prepared catalyst demonstrated high activity, easy recovery and efficient recyclability with no leaching of Rh in the azidolysis of epoxides.

A stir bar sorptive extraction method coupled with deep eutectic solvent based solidification of floating organic droplets-dispersive liquid-liquid microextraction has been used for the simultaneous derivatization and extraction of some acidic pesticides in tomato samples. In this method, initially the analytes are adsorbed on a coated stir bar from tomato juice filled in a narrow tube. After extraction, the stir bar is removed and a water-miscible deep eutectic solvent is used to elute the analytes. Afterward, a derivatization agent and a water-immiscible deep eutectic solvent (as an extraction solvent) with melting point near to room temperature are added to the obtained eluant at µL-levels and the obtained mixture is rapidly injected into deionized water. Under the optimum conditions, the introduced method indicated high enhancement (1543-3353) and enrichment (2530-2999) factors, low limits of detection (7-14 ng/L) and quantification (23-47 ng/L), good linearity (r2 ≥ 0.9982), and satisfactory repeatabilities (relative standard deviation ≤12% for intra- and inter-day precisions at a concentration of 100 ng/L of each analyte). Finally, the proposed method was applied in analysis of the analytes in tomato samples.

Magnesium ethoxide (MGE) was modified by addition of co-solvent (2-propanol) and manganese chloride (MnCl2) together and as a spherical support it was used to obtain Ziegler–Natta (Z–N) catalyst in the polymerization of propylene. The effect of 2-propanol and MnCl2 on nanostructure and morphology of MGE was investigated. The spherical and mesoporous MGE samples were characterized by specific surface area (BET), X-ray diffraction technique (XRD) and scanning electron microscopy (SEM). The relation between the synthetic procedure of MGE support and its structure was discussed. The modification of MGE by 2-propanol and MnCl2 showed a drastic change in the shape of plate-like building blocks of the support. The mean pore size of the modified MGE support was in the range of 4.6–5.2 nm and its surface area was in the range of 31.3–45.4 m2 g−1. The synthesized catalyst with modified MGE showed good activity in propylene polymerization with more than 99% isotacticity. The results showed that the fabricated spherical MGE would be a good condidaite support for Z–N catalysis application.

Isolating tumor exosomes (TEX) secreted by cancer cells can provide valuable information about the state of a tumor. Here, we present a method to rapidly isolate TEX using magnetic nanowires (MNWs)...

Large-scale long-range ordered anodic aluminum oxide and multilayered nanowires (NWs) are attractive to 3-D nanostructured material applications, such as high-density 3-D magnetic memory. This article demonstrates long-range ordered aluminum oxide made by simple and inexpensive double imprinting with line-patterned stamp and uniform iron-gold multilayered NWs fabricated by galvanostatic electrochemical deposition with a single electrolyte bath. These two structural features show potential for future high-density recording systems that require long-range ordered devices separated from each other by insulation to eliminate crosstalk.

To widely commercialize electric vehicles more efforts for their life improvement seem extremely inevitable. Thermal conditions can have profound and nonlinear effects on the degradation rate of an electric vehicle battery pack as well as its performance and safety level. In the current study, both cycle life and calendar life of a commercial LiFePO4 cell are investigated experimentally by means of capacity fading and resistance increment evaluation for 4 different thermal conditions from extremely cold condition of − 20 °C—which is not well studied in the literature—till hot condition of 55 °C. The calendar life tests show that the best condition for storing cells is at 5 °C and 50% SOC and the cycle life tests demonstrate that the best operating temperature is 25 °C based on the dynamic stress test discharge/charge profile (a test profile for electric vehicles). It is also found that the capacity fading and resistance increment at a high temperature such as 50 °C are destructively significant. The presented curves in this paper can also serve as an aging data source for further work on battery lifetime modeling and diagnostics. The role of temperature on the degradation level is also discovered via scanning electron microscopy.

Molecular machines, such as nanocars, have shown promising potential for various tasks, including manipulation at the nanoscale. In this paper, we examined the influence of temperature gradients on nanocar and nanotruck motion as well as C60 - as their wheel - on a flat gold surface under various conditions. We also compared the accuracy and computational cost of two different approaches for generating the temperature gradient. The results show that severe vibrations and frequent impacts of gold atoms at high temperatures increase the average distance of C60 from the substrate, reducing its binding energy. Moreover, the temperature field drives C60 to move along the temperature variation; still, the diffusive motion of C60 remained unchanged in the direction perpendicular to the temperature gradient. Increasing the magnitude of the temperature gradient speeds up its motion parallel to the gradient, while raising the average temperature of the substrate increases the diffusion coefficient in all directions. The temperature field influences the nanocar motion in the same manner as C60. However, the nanocars have a substantially shorter motion range compared to C60. The relatively larger, heavier, and more flexible chassis of the nanocar makes it more sluggish than the nanotruck. In general, the motion of large and heavy surface rolling molecules is less affected by the temperature field compared to small and light molecules. The results of the study show that concentrated heat sources can be employed to push surface rolling molecules or break down their large clusters. We can exploit a temperature field as a driving force to push nanocars in a desired direction on prebuilt pathways.

Objective: The aim of this in vitro study was to investigate the effect of casein phosphopeptide–amorphous calcium phosphate (CPP-ACP)-containing paste (MI Paste) and erbium:yttrium–aluminum–garnet (Er:YAG) laser radiation on the shear bond strength (SBS) of an etch-and-rinse (E and R) adhesives to demineralized dentin. Materials and Methods: Forty-eight carries-free human dentin surfaces were prepared and demineralized using acidic solutions. Then, the samples were randomly divided into four groups (n = 12) receiving different surface treatments. Group A (control group): no additional treatment, Group B: 3 min application of a CPP-ACP-containing cream (MI Paste), Group C: irradiation of Er:YAG laser, and Group D: irradiation of Er:YAG laser combined with 3 min application of CPP-ACP-containing cream (MI paste). Then, a composite cylinder (Filtek™ Ultimate, 3M ESPE) bonded to the surfaces using E and R adhesives (single bond) and the SBS was measured. The SBS data were analyzed using the one-way analysis of variance test followed by Tukey post hoc by SPSS software. Results: The highest SBS to demineralized dentin was observed after the application of CPP-ACP-containing paste (MI paste) without laser radiation (17.14 ± 2.07). The second highest SBS value showed in control group (11.21 ± 1.65) in which demineralized dentin received no additional treatment. However, the application of MI paste combined with Er:YAG laser irradiation resulted in the higher SBS (8.23 ± 1.02) than laser irradiation alone (5.26 ± 1.02), even though both were lower than control group. Conclusions: The application of CPP-ACP-containing paste (MI paste) could increase the SBS of E and R adhesives to demineralized dentin. Furthermore, laser irradiation with and without CPP-ACP application has an adverse effect on SBS.

This work presents an analytical approach to investigate the mechanical buckling of functionally graded material (FGM) thin conical panels surrounded by Winkler–Pasternak foundation and exposed to thermal environments. The material properties of FGMs are assumed to be temperature-dependent and graded only in the thickness direction according to the power-law, sigmoid and the exponential distribution of volume fraction. Eight well-known types of micromechanical models, namely Voigt, Reuss, Mori–Tanaka, Hashin–Shtrikman, modified Wakashima–Tsukamoto, Halpin–Tsai, Tamura and LRVE estimations, are studied to determine the effective two-phase FGM material properties as a function of the particles’ volume fraction considering thermal effects. Further, it is been supposed that the FG conical panel is heated uniformly, linearly and nonlinearly through the thickness. The nonlinear temperature distribution is obtained based on Fourier’s law by applying a semi-analytical procedure. The fundamental relations and the basic equations are derived by using Love’s thin shell theory. Finally, the numerical results are provided to reveal the effect of explicit micromechanical model, FGM profile, temperature distribution with various thermal boundary conditions, foundation conditions and the geometric parameters on the stability of these panels. Additionally, the critical buckling load is compared with that of FG truncated conical shells, cylindrical panels and the cylindrical shells.

In-situ combustion is a thermal enhanced recovery method which has been considered by many researches in recent years. In this study, six samples of Iranian crude oil were selected to inves...

Manganese aluminophosphate (Mn–APO) microcrystals have been synthesized by hydrothermal method and characterized with X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDX). As a potential application in water treatment, Mn–APO particles were evaluated in removal of safranin (CAF) and chrysoidine G (CHG) dyes from aqueous solution. The effects of initial concentrations and pH, contact time, dosage of adsorbent, and temperature were investigated on the dye adsorption capacity of the Mn–APO. The experimental data revealed that an amount of 0.1 g of sorbent demonstrated maximum removal efficiency of CAF and CHG dyes (30 ppm) at pH 7. Two common kinetic models, pseudo-first-order and pseudo-second-order were applied to explain the adsorption kinetics. The adsorption kinetics of CHG and SAF was found to follow a pseudo-second-order kinetic model. Thermodynamic results indicated that the adsorption of CHG and SAF onto Mn–APO particles is endothermic and negative value of ΔG° confirms the spontaneous process. The particles of Mn–APO can be easily regenerated by chemical and physical methods after adsorption. Three common isotherm models, the Langmuir, Temkin and Freundlich were employed to study the interaction of CHG and SAF onto Mn–APO particles. The equilibrium adsorption of Mn–APO was best explained by the Temkin isotherm model. The recycled sorbent can be use after 3 cycles without noticeable change in its activity. The obtained maximum adsorption capacities correspond to an excellent ability to remove dye at ambient temperature. The present study not only introduces new materials for highly efficient and recyclable sorbent, but also facilitates their practical application in environmental remediation.