Simple Analytical Approach Research Articles

Data-driven evaluation of the Paris’ law parameters in polyethylene pipe grades — Increasing the precision of fracture mechanical lifetime estimation

The Paris’ Law parameters A and m are a necessity for predicting lifetimes of structural components under static or fatigue loading that fail due to crack initiation and propagation. Conventional methods require measurements of crack growth kinetics that involve direct or indirect monitoring of physical crack extension during long-term experiments. Usually, measurement series also involve multiple specimens in order to obtain a crack growth controlled failure diagram of an investigated material under relevant load conditions. In this contribution a combination of simple numerical, statistical and analytical approaches is presented to obtain A and m without the need to measure actual crack growth. This is accomplished by reformulating the Paris’ Law to express A as a function of m. The parameter m is varied within a reasonable range to generate an analytical function for A that solves the equation of the Paris’ Law based lifetime for a single specimen. A subsequent superposition of all available specimens reveals an intersection of all A functions at the technically relevant pair of A and m values that are capable of describing the lifetime of all specimens with a minimum error. The obtained best-fitting A and m are in good agreement with literature and are able to predict the lifetime of previously published sample data based upon cyclic Cracked Round Bar test results with an average error of 3.30 ± 2.67%.

Bimetallic complexation for significant fluorescence enhancement of faecal pigment towards water quality testing

Systematic spectroscopic investigations revealed bimetallic complexation of faecal pigments (FP) in waterthrough their multiple binding sites. FP-Zn(II)/Gd(III) complexes showed narrow emission (FWHM ∼ 26 nm) with maximum intensity compared to different bimetallic complexes in water. The fluorescence intensity of bimetallic Zn(II)/Gd(III) complexes of FP increased ∼3–5 fold in aqueous media compared to the FP-Zn(II) complexes, i.e. well-known as Schlesinger’s test. The optimum Zn(II): Gd(III) stoichiometry was observed at 3:2 for maximum FP fluorescence enhancement. The bimetallic FP-Zn(II)/Gd(III) complexes also exhibited higher fluorescence lifetimes and quantum yield than FP-Zn(II) complexes. The photophysical investigations demonstrated that bimetallic Zn(II)/Gd(III) complexation increased the rigidity of chromophores present in FP. Consequently, a decrease in non-radiative decay rate constants (knr) by ∼ 1.5 times was observed for bimetallic complexes compared to FP-Zn(II) in water. Hence, a detection limit of the nanomolar concentration range of FP could be achieved in the aqueous media. The effect of diverse interfering factors (humic acid, water hardness, pH) on the fluorescence behaviour of FP-Zn(II)/Gd(III) complexes was also investigated with an approach mimicking real water samples. Finally, a simple non-extraction analytical approach for sensitive detection of FP in water was demonstrated while also considering the fluorescence matrix interference problem.

Poly(3-Hexylthiophene) Based Bioelectronic Interface Using Conducting Nanofibers (CNFs) for the Sensitive Determination of Folate Receptor Cancer Biomarkers in Human Plasma

Folate receptors (FRs) are important biomarkers that can indicate the presence of various cancers. Sensitive and accurate detection of FRs is crucial for early cancer diagnosis and treatment. The current methods of FRs detection have high cost, potential cytotoxicity, and complex production by relying on metallic nanomaterials, or have low electrical conductivity and sensitivity such as biopolymers. To address these challenges, a new approach using conducting nanofibers (CNFs) as bioelectronic surface was developed. A composite of sodium alginate (SA), a bio-friendly polymer, poly-ethylene oxide (PEO), an antifouling polymer, and poly(3-hexylthiophene) (P3HT), a semi-conducting organic polymer nanofiber was synthesized, with folic acid conjugated to the CNFs as a biorecognition element to target (FRs). The electrochemical and electrical properties were evaluated through cyclic voltammetry and electrochemical impedance spectroscopy in a solution containing both a redox marker and free redox species. The CNFs exhibit electroactivity in buffer solution without a redox marker, owing to the electronic properties of the P3HT of EIS readout. The obtained biosensor significantly improved sensitivity, enabling the detection of FRs with a limit of detection (LOD) of 0.12 pM in human plasma, the high sensitivity compared to all previous approaches and a 25-fold improvement compared to the sensor described in our previous study, with improved selectivity. Additionally, the results showed a good biocompatibility toward MCF-7 breast cancer cells, which opens the way for their use as theragnostic nanoprobes for cancer cells diagnosis and therapy. This study provided a simple, low cost and sensitive analytical approach for folate receptor detection.

Efficient generation of barrier crossing trajectories using approximate Brownian bridges.

We examine continuous random walks that are conditioned to reach one region before another. These conditioned processes are used to generate stochastic trajectories for barrier crossing events, which are generally rare and difficult to sample. The processes are generated using a Brownian bridge technique, resulting in near perfect sampling efficiency without accruing error in the conditional statistics of the process. The construction requires the hitting probability or committer function, which is a solution to the backward Fokker-Planck equation, a partial-differential equationthat can be difficult to solve through general means. Therefore, we derive a one-dimensional approximation through asymptotic methods for barrier crossing trajectories. We show that this approximation has a simple analytical representation and approaches the true solution as the barrier height increases. Brownian bridge trajectories generated with this approximate solution are then shown to result in accurate conditional statistics when used in conjunction with importance sampling, even in the case when potential energy barriers are not large. We show this idea's effectiveness by simulating rare events in a stochastic chemical reaction network (Schögl reaction) with multiple steady states. This methodology shows great promise for future implementation to simulate rare barrier crossing events for a wide variety of physical processes.

Soot Measurements and a Simplified Analytical Formulation-Based Modeling in Laminar Counterflow Diffusion Flames

ABSTRACT The paper presents soot volume fraction measurements and a simplified soot formation model. Soot formation is a complex physicochemical process predominantly modeled using detailed chemistry and stochastic methods. The current work presents a simplified analytical function-based approach to calculate the net soot formation rate by coupling the local mixture-fraction and temperature fields. The validation experiments were carried out in a unique large-diameter (40 mm) counterflow burner for ethylene-air flames at various strain rates and normalized separation (L/D) distances. The soot volume fractions (fv) were determined using Laser Induced Incandescence (LII) technique calibrated by the Light Extinction (LE) method. Further model validations were carried out against the experimental measurements in the literature. The modeling work was performed on OpenFOAM®. The model predicted soot distributions for various peak flame temperatures, stoichiometric mixture-fractions, burner dimensions, fuel-oxidizer compositions, and strain rates with good accuracy. The study underscores the importance of considering two soot formation rate peaks, one at high temperature and one at low temperature, for accurate predictions, unlike a single peak employed in common analytical models. Furthermore, the effect of velocity boundary conditions on soot zone locations and the significance of providing realistic velocity conditions for the simulations are also discussed. Particle Image Velocimetry (PIV) measurements were performed to determine the actual nozzle-exit velocity profiles.

Enhancement of a Simple, Economic and Eco-Friendly Analytical Approach for the Extraction and Determination of Endocrine Disruptors from Plastics in Shrimp

The economic significance of the shrimp industry relies heavily on the comprehensive utilization of all of the shrimp’s parts. However, this importance is often threatened by common challenges such as disease and pollution, caused by prominent contaminants that are capable of exerting adverse effects either directly as physical pollutants or indirectly through the incorporation of additives or adsorbed chemicals. Among these substances are endocrine disruptors, which pose risks to both wildlife and human populations. In this study, 11 endocrine-disrupting compounds were determined (3 bisphenols, 3 phthalates, 3 pesticides, and 2 nonylphenols) through the development of a cost-effective, greener and cost-friendly method based on solid-phase matrix dispersion (MSPD) with high-performance liquid chromatography coupled with diode array detection (HPLC-DAD). Determinations were performed on different parts of the shrimp: the cephalothorax, abdomen, intestine and shell. Several variables were optimized in the extraction, separation and detection phases, resulting in average recoveries of about 90%. The limit of detection (LOD) varies depending on the analyte and matrix. At concentrations of 1 mg/kg in the cephalothorax+shells and 1.25 mg/kg in the abdomen+intestine, all compounds were detected, except for nonylphenols. The developed method has allowed the simultaneous determination of 11 endocrine disruptors in different parts of the shrimp samples. Furthermore, the MSPD has been demonstrated to be an efficacious, selective, and streamlined sample extraction method, eliminating the necessity for pretreatment steps such as centrifugation and filtration, as well as the use of large volumes of solvents.

Simplified Analytical Approach for Calculating the Transverse Load Distribution of Precast Slab Bridges with and without Concrete Overlays

Simplified Analytical Approach for Calculating the Transverse Load Distribution of Precast Slab Bridges with and without Concrete Overlays

Integrated spectroscopic approaches for the facile one pot quantification of olanzapine in pharmaceutical formulation and spiked human plasma

In this work, the xanthene dye, erythrosine B, was employed as a probe for the determination of olanzapine using two fast and highly simple analytical approaches. The assay was based on the formation of a binary complex between the drug and erythrosine B in a slightly acidic aqueous buffered solution. In the first method, the absorbance of the formed product was monitored at 558 nm. The reaction stoichiometry was investigated, and the stability constant of the formed complex was estimated. The linear range of the method that obeyed Beer's law was in the concentration range of 0.6–8.0 µg/ml. The calculated detection and quantitation limits were 0.2 and 0.6 µg/mL. Upon adding the drug solution to erythrosine B, the native fluorescence of the dye was quenched and monitored at 550 nm after excitation at 528 nm. Thus, the fluorescence quenching was utilized as the quantitative signal in the spectrofluorimetric approach. The extent of quenching in the fluorescence intensity was rectilinear with the drug concentration in a range of 0.1–2.5 µg/ml with a detection limit of 0.032 µg/ml. Both approaches were analytically validated based on the guiding rules of the ICH with acceptable results, and were utilized efficiently in the analysis of olanzapine in commercial tablets containing the cited drug. In addition, owing to its high sensitivity and selectivity, the spectrofluorimetric method was applied for drug analysis in spiked human plasma with satisfactory % recoveries. Finally, the greenness of the methods was confirmed using eco-score scale and Analytical Green Evaluation metrics.

A new method for quantification of tomatine-enriched extracts.

Green tomato extracts, an agro-food industry waste, are rich in the glycoalkaloid tomatine, which presents activity against several diseases. High-performance liquid chromatography (HPLC) with ultraviolet (UV) detection is one of the most used techniques for quantification of bioactive compounds. The aim of this study was to optimize and validate a selective HPLC method with diode array detector (DAD) for the quantitative analysis of tomatine extracted from green tomatoes by subcritical water. Chromatographic runs were performed on a InertSustain Phenyl (250 mm × 4.6 mm, 5 μm) analytical column, at a wavelength of 205 nm. A concentration range of 50-580 μg mL-1 was used. The validation process was performed considering the linearity, precision, trueness, limit of detection (LOD) and limit of quantitation (LOQ) of the method. The selected mobile phase composed of acetonitrile and a solution of 20 mmol L-1 potassium dihydrogen phosphate (KH2PO4) pH 3, resulted in suitable retention times and a standard calibration curve with adequate linearity (R2 = 0.9999). The method trueness was evaluated by the recovery assay, obtaining a mean recovery of 105% and the precisions were 1.4% and 0.9% (percentage relative standard deviation, RSD%) for the tomatine standard and extract samples, respectively. The inter-day variability was 2.7-9.0% (RSD%) for the standards and 6.9% (RSD%) for extract. The LOD and the LOQ of the method were determined at 8.0 and 24.1 μg mL-1, respectively. The herein described method was successfully used for the quantification of tomatine in a tomato-derived extract. Furthermore, the method constitutes a simple and rapid analytical approach able to be used as a routine protocol. © 2024 Society of Chemical Industry.

Electrochemiluminescent (ECL) Aptasensor for Lysozyme Using a Graphene Quantum Dot (GQD)-Ruthenium Bipyridine-Silica Nanocomposite

An electrochemiluminescent (ECL) aptasensor for lysozyme (Lyz) based on a graphene quantum dot (GQD)-ruthenium bipyridine (Ru(bpy)3 2+)-silica (GQDs-Ru(bpy)3 2+@SiO2) nanocomposite were prepared by encapsulating GQDs and the luminophore Ru(bpy)3 2+ in silica nanospheres (SiO2). The nanocomposite GQDs-Ru(bpy)3 2+@SiO2 with uniform size exhibited a strong and reproducible ECL response. The nanoprobe (DNA-GQDs-Ru(bpy)3 2+@SiO2) was obtained via amidation between GQDs-Ru(bpy)3 2+@SiO2 and the complementary DNA sequence. The ECL platform was constructed by hybridization between the aptamer and the complementary strand DNA. The specific recognition between aptamer and the target lysozyme maintained the nanoprobe DNA-GQDs-Ru(bpy)3 2+@SiO2 away from the electrode, which led to the decreasing ECL response. The aptasensor exhibited a linear relationship from 0.1 to 100 pg/mL with a detection limit of 1.7 × 10−11 mg/mL. This study provided a simple and sensitive analytical approach for lysozyme.

Assessment of local temperature elevation at the surface of tissue exposed to radiation of milimeter waves using simplified analytical approach

Dominant effect of human exposure to electromagnetic fields in GHz frequency range corresponding to operation of 5G mobile communications systems is tissue heating i.e. local temperature elevation at the body surface, i.e. skin, ear and eyes. For the frequencies below transition frequency of 6GHz specific absorption rate (SAR) is used to quantify the volume heating. On the other hand, the surface heating above 6GHz is quantified via absorbed power density (Sab ). Once these quantities are determined by means of internal field dosimetry procedures it is possible to determine the local surface temperature increase by solving the bio-heat transfer equation. The present paper deals with the calculation of tissue surface heating due to exposure to millimeter waves. Internal dosimetry is based on the planar tissue model exposed to dipole antenna radiation. Electromagnetic model is based on the analytical solution of Pocklington integro-differential equation while the assessment of tissue surface heating in planar tissue model has been carried by analytically solving a simplified variant of the bio-heat transfer equation. Some illustrative results for power density and temperature elevations will be presented for different antenna parameters.

A simplified analytical approach for determining eclipses of satellites occulted by a celestial body

The primary objective of this paper is to construct an analytical model for determining the total duration of eclipse events of satellites. The approach is based on the assumption that the trace formed in the orbital plane, cutting body’s shadow under the classical conical shadow model, can be described as an ellipse. This allows for the derivation of its parameters through the use of classical orbital elements and solar position in the body’s centric frame. Consequently, the problem of identifying satellite occultation events is simplified to searching for points of intersection between two ellipses: the satellite orbit and the shadow. The developed model has been demonstrated to be applicable for a wide range of inclinations, with the exception of cases where the orbital plane of the satellite's motion coincides with that of the sun's in the body-centric frame. It is shown that the shadow function constructed under the aforementioned assumptions can be simplified in the cylindrical shadow model. Several simplifications are provided in the research. The paper also considers the extension of the model to account for the non-spherical shape of celestial bodies and presents an algorithm for accounting for changes in eclipse duration caused by the heliocentric motion of celestial bodies. The model has been validated through numerous tests with a numerical algorithm and satellite real data, as well as with other analytical models.

Dual-Modulation ratiometric fluorescence strategy for cobalt and topotecan detection using Red-Emissive carbon dots

A new ratiometric fluorescence strategy for sensitive and selective detection of cobalt ions (Co2+) and topotecan (TOP) is proposed. The dual-probe system consists of red-emissive nitrogen and sulphur doped carbon dots (R-NS@CDs) and TOP. For Co2+ detection, the fluorescence of R-NS@CDs at 680 nm is enhanced upon addition of Co2+, while complexed TOP emission peak at 545 nm remains constant. This enables ratiometric detection of Co2+ over a range of 5.0–160.0 ng mL−1. The mechanism of R-NS@CDs fluorescence enhancement by Co2+ is elucidated using FTIR, fluorescence spectroscopy, zeta potential measurements, and TEM imaging. For the detection of TOP, a ratiometric probe system comprising R-NS@CDs and Co2+ was utilized. TOP forms a complex with Co2+ bounded to R-NS@CDs, quenching the R-NS@CDs-Co2+ fluorescence and simultaneously the native TOP fluorescence is enhanced. This allows ratiometric quantification of TOP from 1.0-90.0 ng mL−1. The method provides high selectivity and low detection limits of 1.51 ng mL−1 for Co2+ and 0.37 ng mL−1 for TOP. Practical applicability is demonstrated through selective detection of Co2+ in environmental water samples and TOP in real plasma samples. The built-in self-calibration enabled by dual analyte modulation of R-NS@CDs makes this a simple and powerful analytical approach.

Biomechanics as support for forensic expert reports in after pedestrian-car collisions

This paper systematically explores the mechanical properties of facial and cranial bones, aiming to contribute to the understanding of brain and cervical spine injuries from a mechanical/biomechanical perspective. The research also seeks to provide insights applicable in forensic practice, bridging the gap for engineering professionals not typi-cally involved in forensic medicine. Strength and stiffness parameters of facial and cra-nial bones were utilized to analyze forces leading to fractures, proposing a simple analyt-ical approach for determining head velocity upon striking a car windshield. Experimental testing was conducted to examine defects on the windshield resulting from an impactor's crash, simulating head impacts at varying velocities. Two approaches for determining head impact velocity during pedestrian-car collisions were explored. The first, neglect-ing body deformation effects, assumes that the manikin's center of gravity moves at the same speed as the impacting vehicle, resulting in an impact velocity that is approximate-ly twice the car's speed. The second, a more realistic scenario, considers slower move-ment of the body's center of gravity, yielding an impact velocity that is about one and a half times the car's speed, with a specific angle relative to the X-axis. Calculation reveals that head impact velocity decreases with reduced windshield inclination at constant ve-hicle speed. Experimental testing with an adult head impactor monitored impact velocity, acceleration, contact time, and puncture diameter and depth on the vehicle glass. Results align closely with published data, emphasizing higher injury risk near the location of fixation of the windshield to the frame of the vehicle. In forensic investigations, the re-search findings, including newly measured or calculated parameters, offer practical ap-plications. Acknowledging simulation limitations, the study emphasizes the reliance on experimental data for a more realistic understanding. Application of knowledge in expert opinions for car crashes with injuries involves considering windshield defect dimen-sions in relation to speed, minimizing the need for revision by expert opinions. This comprehensive exploration contributes to understanding biomechanical factors influenc-ing injuries, particularly in vehicular accidents, and underscores the importance of em-pirical data in forensic practice. The proposed analytical approach and experimental insights provide valuable tools for forensic professionals and contribute to the broader understanding of injury mechanisms.

Capacity assessment of uncorroded and corroded dapped‐end beams by NLFE and strut‐and‐tie based methods

AbstractThe verification of dapped‐end beams degraded by corrosion is a problem, especially for existing bridges in service. This paper proposes a nonlinear finite element (NLFE) modeling procedure and a simple strut‐and‐tie based procedure for predicting the response of dapped‐end beams subjected to chloride corrosion. Firstly, the finite element modeling strategy, based on the adoption of multilayer shell elements and the PARC_CL 2.1 crack model is described. Then, the degradation effects on concrete, rebars, and steel‐to‐concrete interaction are defined as a function of the propagation period of corrosion. In particular, the effects of corrosion on the reinforcement are modeled by applying a reduction of tensile strength that considers for both the reduction of cross‐section and the ultimate strain caused by pitting. Concrete splitting cracking due to volume expansion during rust formation is modeled by reducing the mechanical properties of concrete. Corrosion effects in steel‐to‐concrete interaction are modeled by applying a bond strength decay to the spring elements connecting corroded rebars—modeled with truss elements—and concrete multilayer shell elements. The proposed finite element procedure is used to study two scenarios based on different spatial distributions of corrosion‐prone areas. Subsequently, a simplified analytical approach based on the strut‐and‐corroded tie method—called S&CT method—is proposed and compared with the finite element outcomes. Finally, the validations of the two proposed methods are presented with respect to a corroded dapped‐end beam, showing that corrosion of rebars affects the resistance mechanisms of the dapped‐end beam, by reducing both resistance and ductility. The proposed simplified analytical S&CT method provides conservative and safe results compared to the numerical NLFE model and to experimental data.

A simple UHPLC-MS/MS method for determination of SET2, a selective antagonist of TRPV2 receptor, in rat plasma samples

Targeting the transient receptor potential vanilloid 2 channels (TRPV2) in order to alleviate or reverse the course of several diseases including multiple cancers, cardiovascular, immunological, or neurological disorders have been a matter of focus for several years now. SET2, a selective TRPV2 inhibitor, represents an innovative molecule which came into recognition in 2019 and seems to be a promising therapeutic modality in cancer and cardiac diseases. Drug discovery and bioanalysis in clinical environment demands simple, excellent, highly reliable, fast, sensitive, and selective analytical approaches which enable unambiguous identification and quantification of demanded molecule. Here, a targeted ultra-high-performance liquid chromatography – tandem mass spectrometry with electrospray ionization was developed for the quantification of SET2 in plasma samples. The developed method enabled analysis of approx. 15 samples within one hour. Simplicity of the whole analytical procedure can be emphasized by a very simple sample pretreatment based only on the protein precipitation with organic acid (here, 2 M tricholoroacetic acid). The validation procedure was characterized by promising validation parameters and excellent sensitivity what was documented by the limit of detection value at pg.mL−1 concentration level. Analytical validation reported intra- and interday accuracy < 15 % for all quality control samples concentration levels. Similarly, excellent level of intra- (0.1 – 4.8 %) and interday (0.5 – 3.3 %) precision for the tested quality control samples was obtained. The applicability of the developed method was proven by quantifying SET2 concentration levels in plasma samples obtained from Wistar rats that were administered this drug intraperitoneally at a dose of 25 mg/kg. We expect that our new analytical method represents a very attractive tool that could be easily implemented in pharmacokinetics studies and/or therapeutic drug monitoring. Moreover, its applicability was confirmed by the new practicability evaluation metric tool.

On the Exact Solution of a Scalar Differential Equation via a Simple Analytical Approach

The existence of the advance parameter in a scalar differential equation prevents the application of the well-known standard methods used for solving classical ordinary differential equations. A simple procedure is introduced in this paper to remove the advance parameter from a special kind of first-order scalar differential equation. The suggested approach transforms the given first-order scalar differential equation to an equivalent second-order ordinary differential equation (ODE) without the advance parameter. Using this method, we are able to construct the exact solution of both the transformed model and the given original model. The exact solution is obtained in a wave form with specified amplitude and phase. Furthermore, several special cases are investigated at certain values/relationships of the involved parameters. It is shown that the exact solution in the absence of the advance parameter reduces to the corresponding solution in the literature. In addition, it is declared that the current model enjoys various kinds of solutions, such as constant solutions, polynomial solutions, and periodic solutions under certain constraints of the included parameters.

Modal properties of floating wind turbines: Analytical study and operational modal analysis of an utility-scale wind turbine

Structural health monitoring through Operational Modal Analysis based on output-only methods has already a long term successful history of applications in conventional civil engineering structures and, more recently, onshore and offshore bottom fixed wind turbines. Although the former application has been proven as a reliable and relevant source of information regarding the dynamic response of the structure and ultimately in the definition of operation strategies, its application to floating offshore structures is yet to be explored, a gap that is tackled in this work. Since the introduction of a floating device, typically associated with very low frequency motions, impacts the relevant modal properties for the tower design, a preliminary and simplified analytical approach is presented, where these effects are properly characterised. The derived expressions, that are ready for design purposes, are validated based on numerical simulations in OpenFAST. After that, experimental data from a full scale floating wind turbine is used as input for Operational Modal Analysis for the first time. Here, not only some key features that are intrinsically associated with these type of structures are unveiled, but also the applicability of output-only methods for dynamic identification is confirmed.

Numerical modelling and experimental validation of squeezing flows in the automobile production

This paper presents a study that combines experimental and numerical approaches to investigate hybrid joining methods involving riveting and adhesive bonding, aimed at enhancing mechanical properties by leveraging their advantages while addressing their limitations. The primary focus of this research was to address the issue of reducing adhesive pockets that commonly occur in such processes. To address this, an experimental setup was developed, enabling precise and reproducible measurements of deflections using digital image correlation (DIC). This allowed for accurate assessment of the extent of adhesive pockets. The device was designed, fabricated, and effectively validated through testing. The findings revealed that employing thicker sheets led to a reduction in adhesive pockets due to minimized sheet deformation and improved adhesive flow. Conversely, increased lengths resulted in the opposite effect. A comparison of materials with the same thickness but varying yield strength indicated minor differences in deflections. Subsequently, the experimental results were subjected to numerical modelling using two distinct methodologies. The first approach employed a Coupled Euler–Lagrange (CEL) framework, while the second employed Smoothed Particle Hydrodynamics (SPH). Prior to application, both methods were validated through squeeze-flow experiments. The numerical modelling utilizing the CEL approach outperformed the SPH method, offering a more accurate estimation of deflections. Finally, predictions of deflections were generated using a simplified analytical approach that incorporated the intricate rheological behaviour of the adhesive, accounting for loading-rate effects. This yielded satisfactory agreement between the predicted and experimental data, particularly at the centre of the specimen, with some deviation towards the edges.

Identification of Kikuchi lines in electron diffraction patterns collected in small-angle geometry.

It is demonstrated that Kikuchi features become clearly visible if reflection high-energy electron diffraction (RHEED) patterns are filtered using digital image processing software. The results of such pattern transformations are shown for SrTiO3 with mixed surface termination for data collected at different azimuths of the incident electron beam. A simplified analytical approach for the theoretical description of filtered Kikuchi patterns is proposed and discussed. Some examples of raw and filtered patterns for thin films are shown. RHEED patterns may be treated as a result of coherent and incoherent scattering of electron waves. The effects of coherent scattering may be considered as those occurring due to wave diffraction by an idealized crystal and, usually, only effects of this type are analysed to obtain structural information on samples investigated with the use of RHEED. However, some incoherent scattering effects mostly caused by thermal vibrations of atoms, known as Kikuchi effects, may also be a source of valuable information on the arrangements of atoms near the surface. Typically, for the case of RHEED, Kikuchi features are hidden in the intensity background and researchers cannot easily recognize them. In this paper, it is shown that the visibility of features of this type can be substantially enhanced using computer graphics methods.