Adsorptive capacity of spray-dried pH-treated bentonite and kaolin powders for ammonium removal

The effectiveness of ammonium (NH₄⁺) adsorption was investigated, using spray-dried, pH-treated bentonite, and kaolin as adsorbents. Each powder's adsorption capacity towards NH₄⁺ was examined after up to 120 min of sample exposure, and results were compared. The zeta potential values for bentonite samples were between ?1.1 and ?19.4 mV, while for kaolin samples, they were between ?35.7 and ?40.9 mV (pH range examined was 2–10). The adsorption isotherm for bentonite showed a fit with the Langmuir model. The pH 10-treated bentonite and as-received bentonite (dispersed as pH 10 in distilled water) showed the highest adsorption capacity towards NH₄⁺. Meanwhile, for kaolin, the adsorption capacity was low and observed only at low NH₄⁺ concentration (100 mg/L and 200 mg/L), with pH 10-treated kaolin showed the highest adsorption capacity.     

Mechanical and optical dynamic model of lung

A multiscale, multiphysics model generates synthetic images of alveolar compression under spherical indentation at the visceral pleura of an inflated lung. A mechanical model connects the millimeter scale of an indenter tip to the behavior of alveoli, walls, and membrane at the micrometer scale. A finite-difference model of optical coherence tomography (OCT) generates the resulting images. Results show good agreement with the experiments performed using a unique indenter-OCT system. The images depict the physical result with the addition of refractive artifacts and speckle. Compression of the alveoli alters the refractive effects, which introduce systematic errors in the computation of alveolar volume. The complete computational model is useful to evaluate new proposed imaging instrumentation and to develop algorithms for obtaining quantitative data on deformation. Among the potential applications, a better understanding of recruitment of alveoli during inflation of a lung, obtained through a combination of models and imaging could lead to improvements in noninvasive treatment of atelectasis.     

NOx formation in post-flame gases from syngas/air combustion at atmospheric pressure

Species concentration measurements specifically those associated with nitrogen oxides (NO_x) can act as important validation targets for developing kinetic models to predict NO_x emissions under syngas combustion accurately. In the present study, premixed combustion of syngas/air mixtures, with equivalence ratio (Φ) from 0.5 to 1.0 and H₂/CO ratio from 0.25 to 1.0 was conducted in a McKenna burner operating at atmospheric pressure. Temperature and NO_x concentrations were measured in the post-combustion zone. For a given H₂/CO ratio, increasing the equivalence ratio from lean to stoichiometric resulted in an increase in NO and decrease in NO₂ concentration near the flame. Increasing the H₂/CO ratio led to a decrease in the temperature as well as the NO concentration near the flame. Based on the axial profiles above the burner, NO concentration increases right above the flame while NO₂ concentration decreases through NO₂-NO conversion reactions according to the path flux analysis. In addition, the present experiments were operated in the laminar region where multidimensional transport effects play significant roles. In order to account for the radial and axial diffusive and convective coupling to chemical kinetics in laminar flow, a multidimensional model was developed to simulate the post-combustion species and temperature distribution. The measurements were compared against both multidimensional computational fluid dynamics (CFD) simulations and one-dimensional burner-stabilized flame simulations. The multidimensional model predictions resulted in a better agreement with the measurements, clearly highlighting the effect of multidimensional transport.     

A Comprehensive Numerical Study on Thermohydraulic Performance of Fluid Flow in Triangular Ducts with Delta-Winglet Vortex Generators

Triangular ducts fitted with various kinds of delta-winglet type vortex generators (VGs) are commonly used to achieve compactness and heat transfer enhancement in many industries. Successive locations of VGs on the inner surfaces of the ducts can be arranged in Common Flow Up (CFU) and Common Flow Down (CFD) orientations. In the present numerical study simultaneous effects of orientation and streamwise distance between VGs on triangular fin performance is carried out considering both global and local flow and heat transfer fields. With the configurations considered in this study, a CFD–CFU orientation and a nondimensional streamwise distance of 0.5 is determined as the best configuration. “RNG k-?” turbulence model with “Enhanced wall treatment” option is determined as the best turbulence model to predict the flow fields inside the triangular duct with built-in VGs, for Reynolds number of 5000.     

Formation of fine and encapsulated mefenamic acid form I particles for dissolution improvement via electrospray method

The potential of using electrostatic atomizer or electrospray in producing fine and encapsulated particle of mefenamic acid (MA) form I with β-cyclodextrin (βCD) was demonstrated in this study. Encapsulated MA-βCD with a molar ratio of 1:2 was prepared in water-ethanol suspension, followed by the electrospray process to atomize the droplet into fine dried particles. The working distance (WD) between the electrospray needle tip and the substrate were varied from 15 to 25?cm. The sizes of encapsulated MA-βCD particles were found to decrease from 91?±?26 to 42?±?35?nm as the WD increased. The dissolution rate of encapsulated particles of MA-βCD was found to be higher compared to the particles of as-received MA and the unencapsulated MA. The presence of the encapsulated MA-βCD was proven by a thermal analysis with the disappearance of MA peak after the atomization process. The x-ray diffraction and FTIR analysis showed that the encapsulation occurred with the existence of new solid phase that was expected from interaction between MA and βCD and the appearance of C?=?C. Further analysis by transmission electron microscopy showed the size and morphology of MA-βCD particles when immersed in water and acetone. Encapsulated MA-βCD particles were solubilized in water but suspended as spherical shape in acetone.     

Reinforced thin-film composite nanofiltration membranes: Fabrication,characterization, and performance testing

Hollow-fiber (HF) membranes have the advantage of a higher packing density compared to flat-sheet and spiral-wound configurations. However, the low pressure tolerance of HF membranes limits their applications in nanofiltration (NF). In this study, reinforced thin-film composite (r-TFC) HF NF membranes were fabricated and evaluated in tests with water containing different salts and organic matter. Reinforced polysulfone ultrafiltration membranes were used as a support for a polyamide layer prepared from piperazine and trimesoyl chloride monomers. The interfacial polymerization conditions were optimized via selection of the trimesoyl chloride reaction time that gave the highest membrane performance. A specific permeate flux of 5.1 L m^–2 h^–1 bar^–1, an MgSO₄ rejection of 69%, and an NaCl rejection of 26% at a transmembrane pressure of 6 bars were obtained with the optimized r-TFC membranes. Performance studies with water characterized by synthetic solution demonstrated removals of the total organic carbon, ultraviolet absorbance at 254 nm, and turbidity in excess of 65, 80, and 90%, respectively. The results of this study illustrate the feasibility of manufacturing r-TFC HFs and using them in water-treatment applications. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 48001.     

Plant‐based metallic nanoparticles as potential theranostics agents: bioinspired tool for imaging and treatment

Theranostic approach provides us a platform where diagnosis and treatment can be carried out simultaneously. Biosynthesis of theranostic‐capable nanoparticles (NPs) can be carried out by phytoconstituents present inside the plants that can act as capping as well as stabilising agents by offering several advantages over chemical and physical methods. This article highlights the theranostic role of NPs with emphasis on potential of plants to produce these NPs through ecofriendly approach that is called ‘Green synthesis’. Biosynthesis, advantages, and disadvantages of plant‐based theronostics have been discussed for better understanding. Moreover, this article has highlighted the approaches required to optimise the plant‐mediated synthesis of NPs and to avoid the toxicity of these agents. Anticipating all of the challenges, the authors expect biogenic NPs can appear as potential diagnostic and therapeutic agents in near future.Inspec keywords: nanofabrication, nanomedicine, nanoparticles, biomedical imaging, patient treatmentOther keywords: bioinspired tool, biosynthesis, theranostic‐capable nanoparticles, Green synthesis, plant‐based theronostics, plant‐mediated synthesis, potential diagnostic agents, therapeutic agents, theranostics agents, plant‐based metallic nanoparticles