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In aquatic environments, the presence of iodine species, including radioactive isotopes like 129I and I2, poses significant environmental and health concerns. Iodine can enter water resources from various sources, including nuclear accidents, medical procedures, and natural occurrences. To address this issue, the use of natural occurring nanoporous minerals, such as zeolitic materials, for iodine removal will be explored. This study focuses on the adsorption of iodine by silver-modified zeolites (13X-Ag, 5A-Ag, Chabazite-Ag, and Clinoptilolite-Ag) and evaluates their performance under different conditions. All materials were characterized using scanning electron microscopey (SEM), energy-dispersive X-ray spectroscopy (EDS), powdered X-ray diffraction (P-XRD), Fourier-transform infrared spectrometry (FTIR), and nitrogen adsorption studies. The results indicate that Chabazite-Ag exhibited the highest iodine adsorption capacity, with an impressive 769 mg/g, making it a viable option for iodine removal applications. 13X-Ag and 5A-Ag also demonstrated substantial adsorption capacities of 714 mg/g and 556 mg/g, respectively, though their behavior varied according to different models. In contrast, Clinoptilolite-Ag exhibited strong pH-dependent behavior, rendering it less suitable for neutral to slightly acidic conditions. Furthermore, this study explored the impact of ionic strength on iodine adsorption, revealing that Chabazite-Ag is efficient in low-salinity environments with an iodine adsorption capacity of 51.80 mg/g but less effective in saline conditions. 5A-Ag proved to be a versatile option for various water treatments, maintaining its iodine adsorption capacity across different salinity levels. In contrast, Clinoptilolite-Ag exhibited high sensitivity to ionic competition, virtually losing its iodine adsorption ability at a NaCl concentration of 0.1 M. Kinetic studies indicated that the pseudo-second-order model best describes the adsorption process, suggesting chemisorption mechanisms dominate iodine removal. Chabazite-Ag exhibited the highest initial adsorption rate with a k2 value of 0.002 mg g−1 h−1, emphasizing its superior adsorption capabilities. Chabazite and Clinoptilolite, naturally occurring minerals, provide eco-friendly solutions for iodine adsorption. Chabazite superior iodine removal highlights its value in critical applications and its potential for addressing pressing environmental challenges. [ABSTRACT FROM AUTHOR]

In this study, we used solvent assisted mechano-synthesis strategies to form multifunctional organic–inorganic nanocomposites capable of removing both organic and inorganic contaminants. A zeolite X (Ze) and activated carbon (AC) composite was synthesized via state-of-the-art mechanical mixing in the presence of few drops of water to form Ze/AC. The second composite (Ze/L/AC) was synthesized in a similar fashion, however this composite had the addition of disodium terephthalate as a linker. Both materials, Ze/AC and Ze/L/AC, were characterized using scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDS), Powdered X-ray diffraction (P-XRD), Fourier-transform infrared spectrometry (FTIR), Accelerated Surface Area and Porosimetry System (ASAP), and thermal gravimetric analysis (TGA). The SEM–EDS displayed the surface structure and composition of each material. The sodium, oxygen and carbon contents increased after linker connected Ze and AC. The P-XRD confirmed the crystallinity of each material as well as the composites, while FTIR indicated the function groups (C=C, O–H) in Ze/L/AC. The contaminant adsorption experiments investigated the effects of pH, temperature, and ionic strength on the adsorption of methylene blue (MB) and Co(II) for each material. In MB adsorption, the first-order reaction rate of Ze/L/AC (0.02 h−1) was double that of Ze/AC (0.01 h−1). The reaction rate of Ze/L/AC (4.8 h−1) was also extraordinarily higher than that of Ze/AC (0.6 h−1) in the adsorption of Co(II). Ze/L/AC composite achieved a maximum adsorption capacity of 44.8 mg/g for MB and 66.6 mg/g for Co(II) ions. The MB adsorption of Ze/AC and Ze/L/AC was best fit in Freundlich model with R2 of 0.96 and 0.97, respectively, which indicated the multilayer adsorption. In the Co(II) adsorption, the data was highly fit in Langmuir model with R2 of 0.94 and 0.92 which indicated the monolayer adsorption. These results indicated both materials exhibited chemisorption. The activation energy of Ze/L/AC in MB adsorption (34.9 kJ mol−1) was higher than that of Ze/L/AC in Co (II) adsorption (26 kJ mol−1). [ABSTRACT FROM AUTHOR]

In this study, we used solvent assisted mechano-synthesis strategies to form multifunctional organic–inorganic nanocomposites capable of removing both organic and inorganic contaminants. A zeolite X (Ze) and activated carbon (AC) composite was synthesized via state-of-the-art mechanical mixing in the presence of few drops of water to form Ze/AC. The second composite (Ze/L/AC) was synthesized in a similar fashion, however this composite had the addition of disodium terephthalate as a linker. Both materials, Ze/AC and Ze/L/AC, were characterized using scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDS), Powdered X-ray diffraction (P-XRD), Fourier-transform infrared spectrometry (FTIR), Accelerated Surface Area and Porosimetry System (ASAP), and thermal gravimetric analysis (TGA). The SEM–EDS displayed the surface structure and composition of each material. The sodium, oxygen and carbon contents increased after linker connected Ze and AC. The P-XRD confirmed the crystallinity of each material as well as the composites, while FTIR indicated the function groups (C=C, O–H) in Ze/L/AC. The contaminant adsorption experiments investigated the effects of pH, temperature, and ionic strength on the adsorption of methylene blue (MB) and Co(II) for each material. In MB adsorption, the first-order reaction rate of Ze/L/AC (0.02 h−1) was double that of Ze/AC (0.01 h−1). The reaction rate of Ze/L/AC (4.8 h−1) was also extraordinarily higher than that of Ze/AC (0.6 h−1) in the adsorption of Co(II). Ze/L/AC composite achieved a maximum adsorption capacity of 44.8 mg/g for MB and 66.6 mg/g for Co(II) ions. The MB adsorption of Ze/AC and Ze/L/AC was best fit in Freundlich model with R2 of 0.96 and 0.97, respectively, which indicated the multilayer adsorption. In the Co(II) adsorption, the data was highly fit in Langmuir model with R2 of 0.94 and 0.92 which indicated the monolayer adsorption. These results indicated both materials exhibited chemisorption. The activation energy of Ze/L/AC in MB adsorption (34.9 kJ mol−1) was higher than that of Ze/L/AC in Co (II) adsorption (26 kJ mol−1). [ABSTRACT FROM AUTHOR]

Chain elongation is one of the common anaerobic fermentation processes in which bacteria convert ethanol and short chain fatty acids (SCFA) into medium chain fatty acids (MCFA). These are single carboxylic acids having six to twelve carbon atoms, with several applications, such as biofuels. Caproate is a promising MCFA, and several technologies were proposed for the valorization of waste to obtain it. Bioelectrochemical systems (BESs) are technologies that are capable of converting the chemical energy of organic/inorganic wastes into value‐added products, using in situ generated H2 or electricity as energy sources. To convert waste biomass into caproate, an electron donor in the form of hydrogen or ethanol should be supplemented within the anaerobic fermentation, which can be used as the electron donor in the cathodic compartment for the conversion of acetate into caproate. This review highlights recent anaerobic and bioelectrochemical processes for the production of caproate. The discussion will also cover the potential applications of this technology, together with obstacles to its use, compared with the conventional anaerobic digestion (AD) process, and considers whether it could be a standalone technology or a complementary one for AD. © 2018 Society of Chemical Industry and John Wiley & Sons, Ltd [ABSTRACT FROM AUTHOR]

Since the initial emergence of two-dimensional graphene (Gr) nano-material, there has been a great interest in its potential applications due to its excellent conductivity, enormous surface area and good mechanical strength. Microbial fuel cells (MFCs) are one of these important promising applications. The limited productivity of MFCs compared to other fuel cell technologies along with the high cost of their components are the two major obstacles to commercialization. Gr is proposed to help overcome such challenges by integrating with biocatalysts for the construction of Gr based MFCs, either as an anode to increase the electron transfer efficiency, or as a cathode to effectively catalyze the oxygen reduction reaction (ORR). This integration is relevant only if the favorable environment for bacterial biofilm adherence to Gr modified surfaces is available. Unfortunately, there is insufficient understanding of the interaction mechanism of bacterial cells with such modified surfaces. Despite this challenge, along with the complexity of the Gr modified electrode fabrication, Gr-based electrodes remain a promising option for developing MFCs to achieve sustainable wastewater treatment and bioelectricity generation. As a reflection on these facts, the aim of this review is to provide critical overview and to evaluate the recent advances for the applications of Gr in MFCs, focusing on electrode fabrication and power generation. Within that context, the concerns about microbial compatibility of Gr will be addressed. [ABSTRACT FROM AUTHOR]

The global atmospheric warming due to increased emissions of carbon dioxide (CO 2 ) has attracted great attention in the last two decades. Although different CO 2 capture and storage platforms have been proposed, the utilization of captured CO 2 from industrial plants is progressively prevalent strategy due to concerns about the safety of terrestrial and aquatic CO 2 storage. Two utilization forms were proposed, direct utilization of CO 2 and conversion of CO 2 to chemicals and energy products. The latter strategy includes the bioelectrochemical techniques in which electricity can be used as an energy source for the microbial catalytic production of fuels and other organic products from CO 2 . This approach is a potential technique in which CO 2 emissions are not only reduced, but it also produce more value-added products. This review article highlights the different methodologies for the bioelectrochemical utilization of CO 2 , with distinctive focus on the potential opportunities for the commercialization of these techniques. [ABSTRACT FROM AUTHOR]

Graphene (Gr)-based materials are a promising nanomaterial for the development of antibacterial surfaces owing to their biocidal activity. However, the effect of the physicochemical features of these materials on their antibacterial activity has yet to be clarified. Gr-based nanomaterials can interact with cellular components, e.g. membranes, proteins and DNA, and initiate a sequence of nanomaterials/bacterial interactions that rely on colloidal energies and active bio-physicochemical interfaces. Analyzing these different interfaces permits the development of anticipated relations between physical/chemical structure and bactericidal activity depending on Gr-based nanomaterial features such as shape, size, hydrophilicity, roughness and functionality. Realizing how nanomaterials are interacting with bacterial cell membranes is correlated to how they affect bactericidal activity and is thus critical for obtaining benign applications. This review analytically discusses specific Gr-based material features related to bacterial interactions, with special focus on the different modes of interaction between Gr-based materials and cell membranes, nucleic acids and lipid bilayers. [ABSTRACT FROM AUTHOR]

Several fighters suffer from tail buffet problems. The buffet phenomenon is the oscillation of aircraft surface components excited as a result of the interaction between the differential pressures associated with turbulent airflow, aircraft structures, and control surfaces. This paper presents the modeling and simulation of a steady-state one-way and two-way fluid-structure interaction for the tail buffet problem of an F/A-18 fighter. The commercial software ANSYS is used to conduct the simulations. The unsteady Reynolds-averaged Navier-Stokes equations with four turbulent models are used to model the fluid domain. Simulation results of two nonlinear eddy viscosity turbulence models were compared with those of two linear viscosity turbulence models and the experimental data. The two linear turbulence models are standard linear Wilcox k-ω and Spalart-Allmaras. The two nonlinear eddy viscosity models are nonlinear eddy viscosity model and Spalart-Allmaras model with rotation and rotation/curvature corrections. The nonlinear eddy viscosity model is based on the standard linear Wilcox k-ω model and uses the formulation of an explicit algebraic Reynolds stress model. The Spalart-Allmaras model with rotation and rotation/curvature corrections turbulence model is the modified Spalart-Allmaras model with a strain-vorticity-based production and curvature treatment. The finite element analysis to model the structural components was conducted by using shell elements. Based on the simulation results, it is concluded that the buffet problem could be simulated as a two-way fluid-structure interaction and by using the nonlinear eddy viscosity model turbulence model as those give better results than the other considered models. [ABSTRACT FROM AUTHOR]

The superior biocidal properties of graphene oxide (GO) nanosheets have enabled their recent application in novel antifouling coatings for membrane filtration. Nevertheless, a practical method for attaching the GO nanosheets to the membrane surface remains a big challenge. This work presents a new methodology for achieving an optimized process for incorporating GO nanosheets onto the surface of thin-film composite (TFC) FO membranes using the bioadhesive polydopamine (pDA). The pDA deposition occurs through self-assembly and oxidative polymerization, both reducing the GO nanosheets and immobilizing them onto the membrane surface. Taguchi's statistical experimental design was used to optimize the process conditions to satisfy the simultaneous enhancement of water flux, reverse solute flux selectivity and antibiofouling performance. Compared to an unmodified membrane the optimum membrane modification both improved pure water flux (21.5%) and reverse solute flux selectivity (80%) and greatly extended the onset of biofouling due to remarkable bactericidal properties. The superior performance of GO-pDA modified membrane in all aspects illustrates its strong potential for application to industrial FO membranes. [ABSTRACT FROM AUTHOR]

Bioelectrochemical systems (BESs) are one of the recent promising technologies developed for their multi-faceted applications such as bioenergy generation, wastewater treatment and synthesis of value added chemicals. Among these applications, microbial fuel cells (MFCs) for wastewater treatment with simultaneous power generation are being widely studied, while the other applications are gaining prominence very recently. A wide range of wastewaters, ranging from domestic to industrial origin, were studied for their potential of power generation in MFCs with their simultaneous treatment. Though, some reviews have been published in the direction of consolidating the data of different wastewaters used as substrates in MFC, detailed review pertaining to the food and agriculture based wastewater was not yet reported. Considering the hidden potential of food and agricultural wastewater, this review article provides a comprehensive view on the MFC research related to these types wastewater. Major bottlenecks in enhancing the power output and treatment efficiencies along with the future directions were also discussed. [ABSTRACT FROM AUTHOR]

Solidbifunctional acid–base catalysts were prepared intwo ways on an amorphous silica support: (1) by grafting mercaptopropylunits (followed by oxidation to propylsulfonic acid) and aminopropylgroups to the silica surface (NH2–SiO2–SO3H), and (2) by grafting only aminopropyl groupsand then partially neutralizing with phosphotungstic acid, relyingon the H2PW12O40–ion for surface acidity (NH2–SiO2–NH3+[H2PW12O40–], denoted as NH2–SiO2–PTA). Surface acidity and basicity were characterized byadsorption calorimetry, using SO2as a probe for surfacebasicity and NH3for surface acidity. Catalytic activitieswere compared in a two-stage cascade: an acid-catalyzed deacetalizationfollowed directly by a base-catalyzed Henry reaction. Overall, theNH2–SiO2–SO3H catalystsshowed higher concentrations and strengths of both acid and base sites,and higher activities than NH2–SiO2–PTA.Both catalysts showed evidence of cooperative acid–base catalysis.Importantly, the bifunctional catalysts exhibited catalytic advantageover physical mixtures of singly functionalized catalysts. [ABSTRACT FROM AUTHOR]

The shortage of sustainable energy and the extensive environmental pollution along with the global warming effect caused by CO 2 emissions are major problems facing the world today. The use of microalgae to overcome these problems has gained enormous research interests in recent years, primarily due to their ability to convert CO 2 by photosynthesis into potential biomass. The merging of such phototrophic organisms into microbial fuel cells (MFCs) is an interesting option since they can act as efficient in situ oxygenators, thus facilitating the cathodic reaction of photosynthetic microbial fuel cells (PMFCs). Also, microalgae can support the efficient removal of phosphorus and nitrogen, as the MFC technology cannot stand-up alone in this field. But such PMFC configurations does possess several challenges, among which PMFC design, output current and sustainability are the major bottlenecks encountering large scale implementation for electricity generation in a cost-effective way. This review goes beyond previous research work by providing not only a detailed update on the current PMFC configurations, but also the critical operational parameters of PMFC, with a scope that extends to cover all types of direct or indirect integration of phototrophic microbes within MFC technology. [ABSTRACT FROM AUTHOR]

Abstract: Biovalorization of dark fermentation effluent (DFE) in a microbial fuel cell (MFC) was studied using the biocatalyst enriched from farm manure. The MFC performance was evaluated in terms of power density, substrate degradation, energy conversion efficiency and shifts in system redox state with operation time and organic loading rate (OLR). Higher power density of 165 mW m−2 (12.5 W m−3) was observed at OLR I, which dropped to 86 mW m−2 at OLR II and 39 mW m−2 at OLR III. The substrate degradation was also higher at OLR I (72%) and diminished with increasing the OLR. The pH showed rapid drop and fluctuations initially when shifted to DFE but adapted over time. Higher coulombic efficiency was observed (48% at OLR I) contributing to a total energy conversion of 11%, which is higher compared to the available literature. However, the MFC performance declined at higher OLR with respect to all the performance indicators. DFE consisted of residual sugars from first stage process along with the volatile fatty acids (VFAs) and alcohols, which contributed for the generation of organic acids with their simultaneous consumption and led to VFA increment in spite of COD removal. Cyclic voltammograms along with the derived electro-kinetics supported the observed shifts. [Copyright &y& Elsevier]

The growth of the biobased economy will lead to an increase in new biorefinery activities. All biorefineries face the regular challenges of efficiently and economically treating their effluent to be compatible with local discharge requirements and to minimize net water consumption. The amount of wastes resulting from biorefineries industry is exponentially growing. The valorization of such wastes has drawn considerable attention with respect to resources with an observable economic and environmental concern. This has been a promising field which shows great prospective toward byproduct usage and increasing value obtained from the biorefinery. However, full-scale realization of biorefinery wastes valorization is not straightforward because several microbiological, technological and economic challenges need to be resolved. In this review we considered valorization options for cereals based biorefineries wastes while identifying their challenges and exploring the opportunities for future process. [ABSTRACT FROM AUTHOR]

Highlights: [•] There is growing interest in the development of microfluidic MFCs with μL volume. [•] μMFCs are serving as a versatile platform for fundamental MFC studies. [•] μMFCs are effective in screening of electrochemically microbes and electrodes. [•] μMFCs generate lower volumetric power density due to the high internal resistance. [•] Manipulation of μMFCs design elements contributes to lower internal resistance. [ABSTRACT FROM AUTHOR]

• Cross-flow in Heat exchanger is studied for different flow speeds using CFD simulations. • Attaching the splitter plates lead to better performance for the heat exchanger. • Increasing of the splitter thickness leads to slight increase in heat transfer and a dramatic pressure drop increase. • As splitter length is increased, the heat transfer is increased, and the pressure drop as well is increased The effect of attaching a splitter plate to the circular tube on the performance of a heat exchanger with a circular tube bank is investigated. A CFD model is developed to simulate the cross-flow behavior inside the heat exchanger. The study of the thermal performance of the tube bank heat exchanger with staggered configuration with and without attached splitter plates to the tubes is conducted. The numerical results are compared with previous experimental and numerical data. Results show that attaching the splitter plates to the tubes can reduce the pressure drop and increase the Nusselt number leading to better overall thermal performance for the heat exchangers and indicate that the splitter plates should be as thin as possible to keep the optimum overall performance. As the splitter thickness is increased to about 20 % of the pipe diameter the heat transfer is slightly increased by about 7 % but the pressure drop is dramatically increased by about 20%. As splitter length is increased up to L/D ratio of 1.5, the heat transfer is doubled, the pressure drop as well is increased by about 20%. [Display omitted] [ABSTRACT FROM AUTHOR]

Porous scaffolds based on gelatin and hydroxyapatite particles (HAp) are promising for applications in bone tissue engineering and regenerative medicine. However, they are not ideal for stress and shock protection due to low compressive strength, brittleness, and poor toughness. Herein, we developed porous hybrid scaffolds by combining multiple components into a single bone scaffold, including hydroxyapatite nanoparticles (HAp NPs), alginate, polyvinyl alcohol (PVA), and gelatin with different gelatin/PVA composition ratios. HAp NPs were synthesized in situ in PVA solution and scaffolds were fabricated using a freeze-drying method. The results showed good physicochemical properties of the scaffolds: formation of pure HAp NPs phase, high porosity, large pore sizes, large swelling capacity depending on varying gelatin/PVA ratios, as well as a long-term degradation rate up to 28 days. The porous scaffolds exhibited compressive strength close to the cancellous bone with stress-strain behavior exhibiting three-stage flexible behavior indicating improved fracture resistance with an energy absorbing capability up to 1.9 MJ/m3. The scaffolds have a yield strength of 70–403 kPa, a compressive strength at 65 % strain of 0.96–1.80 MPa, a nonporous elastic modulus of 10.44–12.40 GPa, and a densification strain of approximately 0.92 %. This work develops three-dimensional (3D) porous hybrid bone scaffolds with mechanical strength within the minimum compressive strength of cancellous bone and mechanical energy absorption capacity favor for cancellous bone repair, bone tissue engineering, and regenerative medicine applications. [Display omitted] • Novel porous hybrid scaffolds were prepared by incorporating multiple components into a single bone scaffold. • Scaffolds were prepared by freeze-drying of HAp, alginate, PVA, and gelatin with different gelatin/PVA composition ratios. • Stress-strain behavior of the scaffolds showed a three-stage flexible behavior mimicking cancellous bone. • Scaffolds have compressive strength and mechanical energy absorption capacity suitable for bone tissue engineering. • The scaffolds present good physicochemical properties, porosity, swelling ratio, and degradation rate. [ABSTRACT FROM AUTHOR]

This paper thoroughly examines lanthanum-doped lead titanate (PbLaxTi(1−0.75x)O3), a perovskite-based ceramic material, focusing on its structural properties, vibrational behavior, and radiation shielding capabilities. Using advanced techniques like X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and transmission electron microscopy (TEM), we explore the intricate relationship between lanthanum doping levels and material properties. Additionally, we assess its radiation shielding potential through metrics. Computational approaches employing the FLUKA code help evaluate theoretical values. Our findings reveal that increasing lanthanum concentration alters crystal atom arrangement, influences vibrational patterns, and enhances radiation shielding effectiveness. Increasing lanthanum concentration resulted in a maximum 7.55% rise in the mass attenuation coefficient (MAC) at 0.059 MeV. The half-value layer (HVL) decreased by 4.68% at 1.33 MeV, and the mean free path (MFP) decreased by 5.78% at 1.41 MeV with increased lanthanum ratio. Moreover, the radiation protection efficiency (RPE) increased from 30.7779 to 32.67442% at 0.059 MeV as lanthanum content increased. These findings offer valuable insights into material characteristics and suggest potential applications in enhancing radiation shielding for medical and industrial purposes. This comprehensive analysis provides practical insights for potential applications, particularly in medical or industrial radiation protection. The data-driven approach here paves the way for future research at the intersection of data science and material science, advancing material design and understanding doped perovskite materials. [ABSTRACT FROM AUTHOR]

Surveillance methods of circulating antibiotic resistance genes (ARGs) are of utmost importance in order to tackle what has been described as one of the greatest threats to humanity in the 21st century. In order to be effective, these methods have to be accurate, quickly deployable, and scalable. In this study, we compare metagenomic shotgun sequencing (TruSeq DNA sequencing) of wastewater samples with a state-of-the-art PCR-based method (Resistomap HT-qPCR) on four wastewater samples that were taken from hospital, industrial, urban and rural areas. ARGs that confer resistance to 11 antibiotic classes have been identified in these wastewater samples using both methods, with the most abundant observed classes of ARGs conferring resistance to aminoglycoside, multidrug-resistance (MDR), macrolide-lincosamide-streptogramin B (MLSB), tetracycline and beta-lactams. In comparing the methods, we observed a strong correlation of relative abundance of ARGs obtained by the two tested methods for the majority of antibiotic classes. Finally, we investigated the source of discrepancies in the results obtained by the two methods. This analysis revealed that false negatives were more likely to occur in qPCR due to mutated primer target sites, whereas ARGs with incomplete or low coverage were not detected by the sequencing method due to the parameters set in the bioinformatics pipeline. Indeed, despite the good correlation between the methods, each has its advantages and disadvantages which are also discussed here. By using both methods together, a more robust ARG surveillance program can be established. Overall, the work described here can aid wastewater treatment plants that plan on implementing an ARG surveillance program. [ABSTRACT FROM AUTHOR]

Organic pollutants in water remain a hazard to the ecosystem, emphasizing the ongoing concern. Therefore, this study focused on the nano-sized spinel ferrite as a photocatalyst for dye degradation and probing how ferrite microstructure influences the photo-degradation efficiency. The NiFe2O4 and ZnFe2O4 nanoparticles (NPs) were synthesized using the co-precipitation and sol–gel methods, respectively. The effects of microstructure changes of pristine and annealed (450, 600, and 800 °C) ferrites were systematically examined using the positron annihilation lifetime (PAL) and Doppler broadening (DB) techniques. Rigorous analysis, featuring X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and transmission electron microscopy (TEM), confirmed the cubic spinel nanostructure for the synthesized ferrite samples as a major phase. The optical properties of the prepared ferrite NPs were studied using the UV–Vis spectroscopy. Particle size ranged from 5.0 to 34.7 nm for NiFe2O4 and from 11.8 to 50.4 nm for ZnFe2O4. UV–Vis spectra unveiled bandgap energy ranges of 3.76–4.34 and 4.31–4.60 eV for Ni and Zn ferrites, respectively. The photo-degradation efficiency of methylene blue dye catalyzed by the prepared Ni and Zn ferrite NPs was investigated. Comparing PAL and DB parameters revealed notable differences, attributed to distinct crystallinity arising from varied synthesis methods. Remarkably, the highest photo-degradation efficiency was observed in the annealed NiFe2O4 at 800 °C and pristine ZnFe2O4 samples, surpassing others. This achievement was attributed to factors such as enhanced ordered crystallinity, increased vibrational modes, optimal particle size, fitting optical properties, and favorable defect characteristics. This study's novelty lies in highlighting the pivotal role of microstructure in governing ferrite NPs photocatalyst performance. We underscore the significance of the defect reduction, regardless of its type, size or concentration, to substantially enhance the photo-degradation efficiency. [ABSTRACT FROM AUTHOR]

The industrial process of olive oil extraction produces huge amounts of wastes that have great negative impact on the environment, because of their high phytotoxicity against soil micro-organisms and aquatic life. Valorization of olive mill waste water ( OMWW) presents significant challenges mainly due to the high phenolic content of the wastewater which leads to high chemical oxygen demand ( COD) and dark color. There is an insistent requirement for strategies to control these wastes through technologies able to minimize their negative environmental effect and to convert them to sustainable resources. Different micro-organisms and techniques have been tested to valorize OMWW. This review, after presenting a general overview, focuses critically on the most significant recent advances in the various types of biological valorization techniques of OMWW. © 2013 Society of Chemical Industry and John Wiley & Sons, Ltd [ABSTRACT FROM AUTHOR]

Oxygen reduction reactions (ORRs) are unanimously a key factor of system performances in bioelectrochemical systems (BESs), low-temperature fuel cells, and generally in several electrochemical platforms. Platinum (Pt)-based catalyst is the finest electrocatalyst for ORR in BESs; however, it is constrained by its low abundance, high price, and poor catalytic durability in an electrochemical setup for cathodic reaction kinetics. In recent years, significant efforts in trimming the metal-based catalyst up to nanoscale to cater high performance of ORR have been explored. Still, there are many opportunities to improve catalyst performance at cathode through proper selection of an efficient low-cost metal-based ORR catalyst. Molybdenum (Mo) with its multi-dimensional form as 2D and 3D layers and synergistic combination with other non-metals offers prospects of extraordinary performance as low-cost metal-based ORR catalyst over the Pt in delivering enhanced ORR potential. The present review throws light on current requirements of a sturdier catalyst material and thus provides a comprehensive review on the continuing efforts in exploring the possibility of Mo as a low-cost metal-based ORR catalyst. This literature analysis would enlighten the significance of ORR in BESs, followed by the electrochemistry of Mo-based cathodic catalyst, its underlying mechanism and performance limiting factors in the operation of ORR. Moreover, the extensive and systematic acumen in the context of Mo-based catalytic formulations for increased ORR potentials including nano-composite Mo-cathode catalyst; development of Mo-catalyst with varied configurations; carbon-supported Mo-catalyst; morphological changes; surface area modifications; and Mo-coupling with other transition metal and its derivatives were discussed in great detail to provide prospective application of Mo-based catalyst. Lastly, numerous opportunities and projections for future research in fabrication, juxtaposition, and implementation of Mo-based cathodic catalysts and consequent recommendations were discussed as conclusive remarks for bringing out the state-of-the-art review on this subject. [ABSTRACT FROM AUTHOR]

Microbial fermentation process development is pursuing a high production yield. This requires a high throughput screening and optimization of the microbial strains, which is nowadays commonly achieved by applying slow and labor-intensive submerged cultivation in shake flasks or microtiter plates. These methods are also limited towards end-point measurements, low analytical data output, and control over the fermentation process. These drawbacks could be overcome by means of scaled-down microfluidic microbioreactors (μBR) that allow for online control over cultivation data and automation, hence reducing cost and time. This review goes beyond previous work not only by providing a detailed update on the current μBR fabrication techniques but also the operation and control of μBRs is compared to large scale fermentation reactors. [ABSTRACT FROM AUTHOR]

Surface coatings to protect materials from mechanical abrasion, fire and microbial colonization are associated with billion dollars of expenses across broad range of industrial, domestic and defence applications. Currently used protective coatings based on heavy metals, halogenated fire-retardation, and biocide agents have considerable environmental concerns due their toxicity, and lack of effectiveness with limited functionality. In this paper, we present engineering of new multifunctional coating based on graphene composites with the ability to provide "3-in-1" protective properties. These multiple functionalities were created with specially designed graphene composite by growing sodium metaborate (NaBO2•xH2O) crystals into graphene oxide (GO) layer during their reduction, which works synergistically as a surface binder, a flame-retardant additive, and an antibacterial agent. The testing of protective coating performances revealed an outstanding mechanical robustness (ASTM-class 4B), and the reduction of bacterial colonization up to -99.92%. The high flame retardant performance of the coated wood, and paper showed non-flammability, strong intumescent effect, and self-extinguishing ability during fire. These protective coatings based on graphene composites due the simplicity of their formulations, scalability, and outstanding performance offer a great potential for their industrial, structural, and environmental applications. [ABSTRACT FROM AUTHOR]

In order to diminish the energy resources, the attempts to convert wave energy into an electrical one and to develop the existing devices are very important issues. Our study investigated numerically the effect of replacing simple front wall with L-shaped front wall on the oscillating water column (OWC) wave energy converter performance. L-Shaped front wall with an entrance duct extended in wave counter flow direction was studied under various regular waves. Two-dimensional numerical wave tank was validated with pervious experimental works. Then, it was used to examine the influence of entrance duct length on the air pressure and the free surface vertical motion in the chamber. The results showed that the type of L-Shaped front wall reduced the air pressure because of the generation of vortices. Despite that, the performance was improved in the case of short entrance duct length in high wave lengths. This improvement was due to the reduction in the shift angle between the pressure curve and free surface vertical velocity curve. In the present work, it was concluded that the counter flow L-shaped front wall with small entrance duct length with respect to the chamber length could improve the average output power in long waves. • Computational Fluid Dynamics. • Wave Energy. • Oscillating Water Column. • Optimization. [ABSTRACT FROM AUTHOR]

Introduction: There has been a concern about the unintended doses to critical structures outside the treatment field due to the increased risk of radiation-induced second cancer following radiotherapy treatments. Today, Monte Carlo (MC) simulation is considered the most accurate method for dose calculations in different domains of medical physics. Material and Methods: The Geant4 Application for Tomographic Emission (GATE) code was used to create an MC model of 6MV Siemens Primus linac. Measurements were taken in a water phantom using an ion chamber to validate the MC model. Dose profiles outside the treatment field at 1.5 (dmax), 5.0 and10.0 cm depths for field sizes from 5×5 to 20×20 cm² were measured in the present study. Out-of-field percentage depth dose (PDD) curves at 0.0, 5.0, and 7.5 cm off axis for field size 10×10 cm2 were investigated for both measurements and simulation. However out-of-field PDDs from 10 to 15 cm off axis for field size 10×10 cm² were studied only by simulation. Results: The comparisons showed agreement between the measured and simulated doses for the out-of-field profiles along the in-plane direction for all considered field sizes and depths, as well as for the PDDs at 0.0 and 5.0 cm off axis, but with less agreement at 7.5 cm off axis. All the simulated out-of-field PDDs at distances ≥ 10 cm off axis had similar trend shapes. Conclusion: The developed MC model is considered a good representation of 6 MV Siemens Primus linac for the out-of-field dose calculation in lieu of measurements. [ABSTRACT FROM AUTHOR]

Finite resources of the world's fossil fuel give rise to the irresistible urge to explore alternative renewable energy routes such as microbial fuel cells (MFCs). The limited productivity is one of the main obstacles for MFC scalability. In this study, a dual-chamber MFC was assembled and equipped with fabricated modified cathodes with titanium dioxide (TiO 2 ) or hybrid graphene (HG) which mainly improved the catalytic activity of the cathode. The graphite paste (GP) bare electrode was modified by both nanomaterials using a green and facile technique. The results showed that the modified cathodes resulted in a considerable improvement for the MFC performance, i.e., the power density reaching levels of 80 mW/m 2 for GP-TiO 2 and 220 mW/m 2 for GP-HG compared to 30 mW/m 2 for GP electrode. Additionally, the modified electrodes exhibited lower charge transfer resistance (R ct ) compared to the bare electrode. Therefore, these modified electrodes, fabricated by an eco-friendly method, could be used as alternatives to the precious expensive metals like Pt. [ABSTRACT FROM AUTHOR]

The out-of-field dose has particular importance because of the increased risk of radiation-induced second cancer and late effects due to low doses for out-of-field organs at risk (OARs). Although the out-of-field doses are clinically related to the doses to OARs, they receive less attention and are not well documented because of the limitations in the treatment planning system (TPS) in calculating them. Today, Monte Carlo (MC) is considered the most accurate and alternate method in calculation of the dose distribution. This study is evaluated the accuracy of the out-of-field dose calculated by the commercial PROWESS©V.5.01 TPS. A comparison for out-of-field dose profiles (DPs) between TPS and MC for field sizes from 10 × 10 cm 2 up to 20 × 20 cm 2 with an increment of 5 cm at depths 1.5, 5, and 10 cm. Out-of-field DPs were calculated for each field size and each depth from the center of the treatment field with an increment of 2 mm along the in-plane direction to a certain distance at which the TPS reported zero doses. Each curve was normalized to the calculated dose at CAX. The relation for the dependence of the out-of-field doses on the field size and depth in the phantom was also evaluated. The comparison between TPS and MC showed that the PROWESS©V.5.01 TPS underestimated the out-of-field dose compared with MC simulation. The degree of the underestimation of dose increases as the distance from the field edge increases. The out-of-field dose depends on field size and depth. Limitations of PROWESS TPS to detect the out-of-field doses could be lead to inaccuracies of underestimation of secondary cancer induction risk associated with these doses. The quantifying of the accuracy of the out-of-field dose calculations by Prowess TPS resulted in underestimated for the out-of-field doses compared with Gate MC simulation in the range from 34% to 65% at different field sizes and depths. The underestimation of the out-of-field dose increased to 65% as the field size and depth increased. • The out-of-field doses clinically relate to the doses to organs at risk. • Validation of Monte Carlo model for dose evaluation outside the treatment field. • Discrepancies between Monte Carlo dose calculations and measurements. • Second cancer risk assessment. • Variability of a peripheral dose among various linac geometries. [ABSTRACT FROM AUTHOR]

A novel bacterial strain was isolated and identified asBacillus pumilus,with the capability to produce cholesterol oxidase enzyme (55 kDa). The production of the enzyme was optimized via two-step statistical approach. Out of eight factors screened in Plackett–Burman, only four had significant effects on enzyme activity. The optimization process of these four variables by Box–Behnken revealed that the maximum enzyme activity (90 U/mL) was significantly obtained after 6 days of fermentation with 0.3%, 1% and 0.2% of NH4NO3, yeast extract and Tween 80, respectively. The purified enzyme showed optimum activity at pH 7.5 and temperature of 40 °C. The enzyme retained 100% of its activity after storage at 40 °C for 60 min. The enzyme also exhibited enhanced stability in the presence of Tween 80, methanol and isopropanol. This solvent and thermal stress tolerant enzyme, produced byB. pumilus, may provide a practical option for industrial and analytical applications. [ABSTRACT FROM PUBLISHER]

The anoxic, alkaline hydrolysis of cellulosic materials generates a range of cellulose degradation products (CDP) including α and β forms of isosaccharinic acid (ISA) and is expected to occur in radioactive waste disposal sites receiving intermediate level radioactive wastes. The generation of ISA's is of particular relevance to the disposal of these wastes since they are able to form complexes with radioelements such as Pu enhancing their migration. This study demonstrates that microbial communities present in near-surface anoxic sediments are able to degrade CDP including both forms of ISA via iron reduction, sulphate reduction and methanogenesis, without any prior exposure to these substrates. No significant difference (n = 6, p = 0.118) in α and β ISA degradation rates were seen under either iron reducing, sulphate reducing or methanogenic conditions, giving an overall mean degradation rate of 4.7×10−2 hr−1 (SE±2.9×10−3). These results suggest that a radioactive waste disposal site is likely to be colonised by organisms able to degrade CDP and associated ISA's during the construction and operational phase of the facility. [ABSTRACT FROM AUTHOR]