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The purpose of this paper is to focus on the antioxidant properties of two phenolic-rich varieties of Nigerian local rice and their anti-cholinesterase potential after in vitro-simulated gastrointestinal digestion, with the aim of establishing their actual antioxidant and nutraceutical potential after their passage through the gastrointestinal tract upon consumption.

Two local rice varieties, commonly referred to as “Gboko” and “Ofada” rice commonly grown in Benue State, a middle belt region of Nigeria and south western regions of Nigeria, respectively, were locally processed. Each of the processed grains were divided into two portions; one portion was left uncooked, while the second portion was boiled conventionally as eaten, dried and subsequently milled into powder. The milled samples of the raw and boiled rice were treated with acidified methanol to obtain the methanol extracts; another portion of each samples was subjected to in vitro enzyme digestion using standard methods to mimic human digestion; and the third portion was treated using the same scheme of in vitro digestion without the sets of enzyme which was used to serve as a control for enzyme treatment. The quali-quantitative phenolic profiles of the two local varieties were carried out with the aid of high-performance liquid chromatography with diode-array detection (HPLC-DAD) method. The antioxidant potential and anti-cholinesterase action of the methanolic extracts, the simulated in vitro digested model and the enzyme-treated controls of the rice samples were determined using standard methods and data obtained were subjected to ANOVA; the differences of means were separated using Duncan’s multiple range test (DMRT).

The quali-quantitative assessment of phenolic compounds in the two studied local varieties revealed the presence of some phenolic acids and flavonoids, with a decreased level of most of the identified phenolic compounds after boiling. In vitro enzyme-digested rice for both raw and boiled rice samples showed significantly higher total phenolic content, total flavonoid content, ferric-reducing antioxidant power, 2, 2′-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid (ABTS+) scavenging and NO− inhibitory activities than the aqueous-methanolic extracts and the enzyme-treated controls. The aqueous-methanolic extracts displayed a higher 1, 1 diphenyl-2-picrylhdrazyl radical scavenging activity and inhibited Fe2+-induced lipid oxidation in rat’s brain and liver homogenate than that displayed by the in vitro enzyme-digested samples. In vitro enzyme-digested and boiled “Gboko” and “Ofada” rice and raw “Ofada” rice have the potential of inhibiting acetylcholine esterase (AChE) activity. While methanolic extracts of raw and boiled “Ofada” and “Gboko” rice exhibited the potential to inhibit butrylcholinesterase activity. The result of this paper indicates that the selected rice varieties possess antioxidant capacities which are better released after the simulated in vitro enzyme digestion; the result also showed the anti-cholinesterase potential of the studied rice grains and, therefore, they can be considered as nutraceutical health supplements.

The paper has demonstrated the antioxidant potentials of the phenolic-containing two Nigerian local rice varieties and established their anti-cholinesterase potential after simulated in vitro enzyme digestion.

The purpose of this paper is to investigate the dynamical behavior of heat and mass transfer of non-Newtonian nanofluid flow through parallel horizontal sheet with heat-dependent thermal conductivity and magnetic field. The effects of thermophoresis and Brownian motion on the Eyring‒Powell nanofluid heat and concentration are also considered. The flow fluid is propelled by squeezing force and constant pressure gradient. The hydromagnetic fluid is induced by periodic time variations.

The dimensionless momentum, energy and species balance equations are solved by the spectral local linearization method that is employed to numerically integrate the coupled non-linear differential equations.

The response of the fluid flow, temperature and concentration to variational increase in the values of the parameters is graphically presented and discussed accordingly.

The validity of the method used was checked by comparing it with previous related article.

Whilst a modest number of investigations have been undertaken concerning nanofluids (NFs), the exploration of fluid flow under exponentially stretching velocities using NFs remains comparatively uncharted territory. This work presents a distinctive contribution through the comprehensive examination of heat and mass transfer phenomena in the NF ND–Cu/H₂O under the influence of an exponentially stretching velocity. Moreover, the investigation delves into the intriguing interplay of gyrotactic microorganisms and convective boundary conditions within the system.

Similarity transformations have been used on PDEs to convert them into dimensionless ODEs. The solution is derived by using the homotopy analysis method (HAM). The pictorial notations have been prepared for sundry flow parameters. Furthermore, some engineering quantities are calculated in terms of the density of motile microbes, Nusselt and Sherwood numbers and skin friction, which are presented in tabular form.

The mixed convection effect associated with the combined effect of the buoyancy ratio, bioconvection Rayleigh constant and the resistivity due to the magnetization property gives rise to attenuating the velocity distribution significantly in the case of hybrid nanoliquid. The parameters involved in the profile of motile microorganisms attenuate the profile significantly.

The current simulations have uncovered fascinating discoveries about how metallic NFs behave near a stretched surface. These insights give us valuable information about the characteristics of the boundary layer close to the surface under exponential stretching.

The novelty of the current investigation is the analysis of NF ND–Cu/H₂O along with an exponentially stretching velocity in a system with gyrotactic microorganisms. The investigation of fluid flow at an exponentially stretching velocity using NFs is still relatively unexplored.

The purpose of this paper is to consider heat and mass transfer on magnetohydrodynamics (MHD) Williamson fluid flow over a slendering stretching sheet with variable thickness in the presence of radiation and chemical reaction. All pertinent flow parameters are discussed and their influence on the hydrodynamics, thermal and concentration boundary layer are presented with the aid of the diagram.

The governing partial differential equations are reduced into a system of ordinary differential equations with the help of suitable similarity variables. A discrete version of the homotopy analysis method (HAM) called the spectral homotopy analysis method (SHAM) was used to solve the transformed equations. SHAM is efficient, and it converges faster than the HAM. The SHAM provides flexibility when solving linear ordinary differential equations with the use of the Chebyshev spectral collocation method.

The findings revealed that an increase in the variable thermal conductivity hike the temperature and the thermal boundary layer thickness, whereas the reverse is the case for velocity close to the wall.

The uniqueness of this paper is the exploration of combined effects of heat and mass transfer on MHD Williamson fluid flow over a slendering stretching sheet. The Williamson fluid term in the momentum equation is expressed as a linear function and the viscosity and thermal conductivity are considered to vary in the boundary layer.

The purpose of this study is to review the existing fatigue and vibration-based structural health monitoring techniques and highlight the advantages of combining both approaches.

Fatigue monitoring requires a fatigue model of the material, the stresses at specific points of the structure, a cycle counting technique and a fatigue damage criterion. Firstly, this paper reviews existing structural health monitoring (SHM) techniques, addresses their principal classifications and presents the main characteristics of each technique, with a particular emphasis on modal-based methodologies. Automated modal analysis, damage detection and localisation techniques are also reviewed. Fatigue monitoring is an SHM technique which evaluate the structural fatigue damage in real time. Stress estimation techniques and damage accumulation models based on the S-N field and the Miner rule are also reviewed in this paper.

A vast amount of research has been carried out in the field of SHM. The literature about fatigue calculation, fatigue testing, fatigue modelling and remaining fatigue life is also extensive. However, the number of publications related to monitor the fatigue process is scarce. A methodology to perform real-time structural fatigue monitoring, in both time and frequency domains, is presented.

Fatigue monitoring can be combined (applied simultaneously) with other vibration-based SHM techniques, which might significantly increase the reliability of the monitoring techniques.

This study aims to investigate the flow behavior of aluminum oxide–water nanofluid with variable viscosity flowing through the microchannel parallel with the ground, with low aspect ratio. The study focuses on the first and second law analyses of Poiseuille flow using water as the base fluid with alumina nanoparticles suspended in it. Combined effects of thermal radiation, viscous dissipation, variable viscosity, nanoparticle shape factor and volume fraction on the thermal performance are studied and the in-built irreversibility in the process is examined.

The governing equations with dimensions are reduced to non-dimensional equations by using dimensionless quantities. Then, the Runge–Kutta–Fehlberg shooting scheme tackles the present non-linear equations.

The outcomes of the present analysis reveal that the activation energy parameter with its increase, depletes the exergetic effectiveness of the system, thus defending the fact to keep the activation energy parameter the lowest as possible for the system efficiency. In addition, thermal radiation and Biot number enhance the release of heat energy, thereby cooling the system. Bejan number graph exhibits the decreasing behavior for the increased nanoparticle shape factor, whereas the temperature enhances with the rise in nanoparticle shape factor.

The effects of nanoparticle shape factor in Poiseuille flow for alumina–water nanoliquid in low aspect ratio microchannel is inspected at the earliest. Exergetic effectiveness of the system is studied and heat transfer characteristics are explored for thermal radiation effect and activation energy parameter. Besides, BeηSphere>BeηBlades.

Nonlinear mixed-convective entropy optimized the flow of hyperbolic-tangent nanofluid (HTN) with magnetohydrodynamics (MHD) process is considered over a vertical slendering surface. The impression of activation energy is incorporated in the modeling with the significance of nonlinear radiation, dissipative-function, heat generation/consumption connection and Joule heating. Research in this area has practical applications in the design of efficient heat exchangers, thermal management systems or nanomaterial-based devices.

Suitable set of variables is introduced to transform the PDEs (Partial differential equations) system into required ODEs (Ordinary differential equations) system. The transformed ODEs system is then solved numerically via finite difference method. Graphical artworks are made to predict the control of applicable transport parameters on surface entropy, Bejan number, Sherwood number, skin-friction, Nusselt number, temperature, velocity and concentration fields.

It is noticed from present numerical examination that Bejan number aggravates for improved estimations of concentration-difference parameter a_2, Eckert number E_c, thermal ratio parameter ?_w and radiation parameter R_d, whereas surface entropy condenses for flow performance index n, temperature-difference parameter a_1, thermodiffusion parameter N_t and mixed convection parameter ?. Sherwood number is enriched with the amplification of pedesis-motion parameter N_b, while opposite development is perceived for thermodiffusion parameter. Lastly, outcomes are matched with formerly published data to authenticate the present numerical investigation.

To the best of the authors' knowledge, no investigation has been reported yet that explains the entropic behavior with activation energy in the flowing of hyperbolic-tangent mixed-convective nanomaterial due to a vertical slendering surface.

This paper aims to evaluate the effects of banana (Musa) peel and guava (Psidium guajava) leaves extract as mordants on jute–cotton union fabrics dyed with onion skin extract as a natural dye.

The dye was extracted from the outer skin of onions by boiling in water and later concentrated. The bio-mordants were prepared by maceration using methanol and ethanol. The fabrics were pre-mordanted, simultaneously mordanted and post-mordanted with various concentrations according to the weight of the fabric. The dyed and mordanted fabrics were later subjected to measurement of color coordinates, color strength and colorfastness to the washing test. Furthermore, the dyed samples were characterized by Fourier transform infrared, and different chemical bonds were analyzed by X-ray photoelectron spectroscopy analysis.

Significant improvement was obtained in colorfastness and color strength values in various instances using banana peel and guava leaves as bio mordants. Post-mordanted with banana peel provided the best results for wash fastness. Better color strength was achieved by fabric post-mordanted with guava leave extracts.

Sustainable dyeing methods of natural dyes using banana peel and guava leaves as bio mordants were explored on jute–cotton union fabrics. Improvement in colorfastness and color strength for various instances was observed. Thus, this paper provides a promising alternative to metallic salt mordants.

This study aims to investigate the relationship between structural damage and sensitivity indices using the Hilbert‐Huang transform (HHT) method.

The relationship between structural damage and the sensitivity indices is obtained by using the HHT method. Three sensitivity indices are proposed: the ratio of rotation (RR), the ratio of shifting value (SV) and the ratio of bandwidth (RB). The nonlinear single degree of freedom and multiple degree of freedom models with various predominant frequencies are constructed using the SAP2000 program. Adjusted PGA El Centro and Chi‐Chi (TCU068) earthquake data are used as the excitations. Next, the sensitivity indices obtained using the HHT and the fast Fourier transform (FFT) methods are evaluated separately based on the acceleration responses of the roof structures to earthquakes.

Simulation results indicate that, when RR < 1, the structural response is in the elastic region, and neither the RB nor SV in the HHT and FFT spectra change. When the structural response is nonlinear, i.e. RR1, a positive trend of change occurs in RB and RR, while in the HHT spectra, SV increases with an increasing RR. Moreover, the FFT spectra reveal that SV changes only when the RR is sufficiently large. No steady relationship between the RB and the RR can be found.

The paper demonstrates the effectiveness of the HHT method.

The purpose of this paper is to introduce a methodology aimed to detect debonding induced by low impacts energies in typical aeronautical structures. The methodology is based on high frequency sensors/actuators system simulation and the application of elliptical triangulation (ET) and probability ellipse (PE) methods as damage detector. Numerical and experimental results on small-scale stiffened panels made of carbon fiber-reinforced plastic material are discussed.

The damage detection methodology is based on high frequency sensors/actuators piezoceramics system enabling the ET and the PE methods. The approach is based on ultrasonic guided waves propagation measurement and simulation within the structure and perturbations induced by debonding or impact damage that affect the signal characteristics.

The work is focused on debonding detection via test and simulations and calculation of damage indexes (DIs). The ET and PE methodologies have demonstrated the link between the DIs and debonding enabling the identification of position and growth of the damage.

The debonding between two structural elements caused in manufacturing or in-service is very difficult to detect, especially when the components are in low accessibility areas. This criticality, together with the uncertainty of long-term adhesive performance and the inability to continuously assess the debonding condition, induces the aircrafts’ manufacturers to pursuit ultraconservative design approach, with in turn an increment in final weight of these parts. The aim of this research’s activity is to demonstrate the effectiveness of the proposed methodology and the robustness of the structural health monitoring system to detect debonding in a typical aeronautical structural joint.