Experimental and numerical study on simultaneous effects of scattering and absorption on fluorescence spectroscopy of a breast phantom

Detection of dysplastic lesions can decrease morbidity and mortality caused by cancer. The fluorescence spectroscopy is a noninvasive method of detecting dysplasia in several organs. During dysplastic progression, fluorescence intensity of spectrum is changed due to variation in absorption and scattering coefficients of tissue. In this work we have experimentally verified simultaneous effects of scattering and absorption coefficients on fluorescence intensity of different tissue like phantoms with the same optical properties as the human breast ductal carcinoma. The results are compared with those obtained by Monte Carlo simulation and good agreement between them is observed. This provides an important detecting method to discriminate dysplastic tissue from normal tissue.     

Identification of a metastable uranium metal–organic framework isomer through non-equilibrium synthesis

Since the structure of supramolecular isomers determines their performance, rational synthesis of a specific isomer hinges on understanding the energetic relationships between isomeric possibilities. To this end, we have systematically interrogated a pair of uranium-based metal–organic framework topological isomers both synthetically and through density functional theory (DFT) energetic calculations. Although synthetic and energetic data initially appeared to mismatch, we assigned this phenomenon to the appearance of a metastable isomer, driven by levers defined by Le Châtelier''s principle. Identifying the relationship between structure and energetics in this study reveals how non-equilibrium synthetic conditions can be used as a strategy to target metastable MOFs. Additionally, this study demonstrates how defined MOF design rules may enable access to products within the energetic phase space which are more complex than conventional binary (e.g., kinetic vs. thermodynamic) products.

Identifying the relationship between structure and energetics in a uranium MOF isomer system reveals how non-equilibrium synthetic conditions can be used as a strategy to target metastable MOFs.     

Synthesis and characterization of RuO<Subscript>2</Subscript>@ZrO<Subscript>2</Subscript> core–shell nano particles as heterogeneous catalyst for oxidation of benzylic alcohols in different conditions

In this study, new RuO₂@ZrO₂ core–shell nanoparticles have been produced using simple procedure and characterized by the spectroscopic methods (XRD and HR-TEM techniques). Catalytic activity of the synthesized nano powders has been investigated in the liquid-phase selective oxidation of benzyl alcohols. Also, the effect of some parameters such as optimum weight ratio for Ru doping, catalyst, oxidant type and various solvents was studied in room temperature, reflux, ultrasound, microwave conditions and UV–vis irradiation. The catalyst exhibits excellent activity and high conversion under mild conditions. Furthermore, this reagent was recycled and reused three times in the model reaction.     

Thermal Conduction in Deforming Isotropic and Anisotropic Granular Porous Media with Rough Grain Surface

The measurement of fluid pressure inside pores is a major challenge in experimental studies of two-phase flow in porous media. In this paper, we describe the manufacturing procedure of a micro-model with integrated fibre optic pressure sensors. They have a circular measurement window with a diameter of 260 \(\upmu \hbox {m}\), which enables the measurement of pressure at the pore scale. As a porous medium, we used a PDMS micro-model with known physical and surface properties. A given pore geometry was produced following a procedure we had developed earlier. We explain the technology behind fibre optic pressure sensors and the procedure for integrating these sensors into a micro-model and demonstrate their utility for the measurement of pore pressure under transient two-phase flow conditions. Finally, we present and analyse results of single and two-phase flow experiments performed in the micro-model and discuss the link between small-scale fast pressure changes with pore-scale events.     

A finite volume method for solving the two-sided time-space fractional advection-dispersion equation

We present a finite volume method to solve the time-space two-sided fractional advection-dispersion equation on a one-dimensional domain. The spatial discretisation employs fractionally-shifted Grünwald formulas to discretise the Riemann-Liouville fractional derivatives at control volume faces in terms of function values at the nodes. We demonstrate how the finite volume formulation provides a natural, convenient and accurate means of discretising this equation in conservative form, compared to using a conventional finite difference approach. Results of numerical experiments are presented to demonstrate the effectiveness of the approach.     

Immobilization and voltammetric detection of human interleukine-2 gene on the pencil graphite electrode

The immobilization and differential pulse anodic voltammetry (DPAV) of a 20-mer oligonucleotide related to the human interleukine-2 (hIL-2) using renewable pencil graphite electrode (PGE) is described. The influences of electrochemical pretreatment of PGE on the ability of the electrode in hIL-2 adsorption, and conditions of hiIL-2 immobilization on PGE including immobilization potential and time, sodium chloride concentration as well as stirring of the solution were studied and optimum conditions were suggested. Accordingly, the electrochemical pretreatment of the polished PGE by electrostatic procedure at 1.80 V for 5 min in 0.50 M acetate buffer solution of pH 4.8 is proposed as the optimum pre-treatment procedure. Similarly, the obtained optimum conditions for immobilization of hIL-2 on the activated PGE was an immobilization duration of 5 min at applied potential of 0.50 V. Trace levels of hIL-2 was readily detected following only 5 min immobilization period with detection limit of 6 nM.     

Metal matrix composites for sustainable lotus-effect surfaces

The lotus effect involving roughness-induced superhydrophobicity is a way to design nonwetting, self-cleaning, omniphobic, icephobic, and antifouling surfaces. However, such surfaces require micropatterning, which is extremely vulnerable to even small wear rates. This limits the applicability of the lotus effects to situations when wear is practically absent. To design sustainable superhydrophobic surfaces, we suggest using metal matrix composites (MMCs) with hydrophobic reinforcement in the bulk of the material, rather than only at its surface. Such surfaces, if properly designed, provide roughness and heterogeneity needed for superhydrophobicity. In addition, they are sustainable, since when the surface layer is deteriorated and removed due to wear, hydrophobic reinforcement and roughness remains. We present a model and experimental data on wetting of MMCs. We also conducted selected experiments with graphite-reinforced MMCs and showed that the contact angle can be determined from the model. In order to decouple the effects of reinforcement and roughness, the experiments were conducted for initially smooth and etched matrix and composite materials.     

Simultaneous kinetic-spectrophotometric determination of sulfide and sulfite by partial least squares and genetic algorithm variable selection

Simultaneous multicomponent analysis is usually carried out by multivariate calibration models such as partial least squares (PLS) that utilize the full spectrum. It has been demonstrated by both experimental and theoretical considerations that better results can be obtained by a proper selection of the spectral range to be included in calculations. A genetic algorithm is one of the most popular methods for selecting variables for PLS calibration of mixtures with almost identical spectra without loss of prediction capacity. In this work, a simple and precise method for rapid and accurate simultaneous determination of sulfide and sulfite ions based on the addition reaction of these ions with new fuchsin at pH 8 and 25°C by PLS regression and using a genetic algorithm (GA) for variable selection is proposed. The concentrations of sulfide and sulfite ions varied between 0.05–2.50 and 0.15–2.00 μg/mL, respectively. A series of synthetic solutions containing different concentrations of sulfide and sulfite were used to check the prediction ability of GA-PLS models. The root mean square error of prediction with PLS on the whole data set was 0.19 μg/mL for sulfide and 0.09 μg/mL for sulfite. After the application of GA, these values were reduced to 0.04 and 0.03 μg/mL, respectively. The text was submitted by the authors in English.     

Inclined surface slip flow of nanoparticles with subject to mixed convection phenomenon: Fractional calculus applications

The interest of researchers towards the nanofluids is noticed in recent years due to leading applications in thermal systems and industrial framework. Referring to such motivations, current study explores the role of velocity slip effects for the mixed convection flow of nanofluid endorsed due to inclined surface. The Casson base fluid model for which the thermal impact needs to be improved. The analysis is observed when the role of velocity slip is important. The modeling of unsteady free convective flow problem yields partial differential system. The Atangana-Baleanu (AB) and Caputo-Fabrizio (CF) fractional operators are implemented in order to simulates the computation of problem. The graphical presentations are prepared in order to check the physical dynamic of parameters.