Specimen Plane Research Articles

The Shear Behavior of the Curved Interface in Polyurethane-Concrete Composite Structures

Polyurethane grouting trenchless technology has been widely applied to the rehabilitation of concealed defects in engineering structures. The interfacial properties between polyurethane and engineering structures are key factors determining the stability of the composite structure. In practical applications, the interface shapes of different engineering structures vary significantly, and the influence of the interface shape on interfacial properties should not be overlooked. This study focuses on engineering structures with curved interfaces, such as pile foundations, pipelines, and tunnels. Direct shear tests were conducted on polyurethane and concrete composite specimens with curved interfaces. A comparative analysis of the shear behavior between curved and planar composite specimens was performed, and the influence of arc diameter and polyurethane density on the shear behavior of curved and planar composite specimens was investigated. Additionally, SEM (Scanning Electron Microscopy) was used to conduct a microscopic examination of the interfaces with different polyurethane densities after failure, and the microscopic shear mechanisms between polyurethane and concrete materials were explored. The results revealed that the shear behavior of curved specimens was significantly higher than that of planar specimens. The shear strengths of curved specimens with diameters of 400 mm, 500 mm, and 700 mm were approximately 1.50, 1.39, and 1.10 times those of planar specimens, respectively. With increasing polyurethane density, the variation trend of shear strength in curved specimens was similar to that of planar specimens. However, significant differences were observed in the shear modulus, peak displacement, and shear residual strength between curved and planar specimens as the polyurethane density varied. Different diameter curved interface specimens exhibited a similar trend of shear strength variation with polyurethane density, gradually decreasing as the curvature diameter increased, and ultimately approaching that of planar specimens.

In Vitro Wear of Human Enamel Against Monolithic Zirconia After Staining, Glazing and Polishing Treatments.

To evaluate the effect of staining, glazing, and polishing of stabilized zirconia with 5 mol% of yttrium oxide (5Y-TZP) on the wear behavior of opposing tooth enamel. The plane specimens of 5Y-TZP were divided into 6 groups (n = 10), according to surface treatment: as sintered, staining, glazing, polishing, staining followed by glazing, and staining followed by polishing, and positioned against tooth enamel during the two-body wear test (20 N, 2 Hz, until completing 300,000 cycles). The wear rates of tooth enamel were evaluated using a profile projector and a digital pachymeter as a measure of vertical height loss. The data were analyzed by one-way ANOVA and a Tukey post hoc test (α = 0.05). Polishing reduced the vertical height loss (p < 0.001) while there was no difference among other groups. Polishing is recommended as a finishing procedure to reduce the wear rates of tooth enamel, and finishing procedures (glazing or polishing) performed after staining did not affect the vertical height loss of tooth enamel. Polishing is the recommended finishing procedure for preshaded 5Y-TZP to reduce the wear rates of opposing tooth enamel. Staining is applied to the occlusal surface to reproduce the pigmented groove appearance, and glazing or polishing performed after staining did not affect the wear rates of opposing tooth enamel.

Enhancing Quality Control in the Mix Design of High-Strength Concrete Using a Capacity-Based Approach

The mix design of concrete is an important aspect that affects its strength and durability. This paper aims to revisit the existing mix design method given in IS 10262:2019 through a capacity-based approach. The approach involves identifying the possible failure modes in concrete and eliminating the undesirable ones leading to significant reduction in dispersion. This is accomplished by utilizing coarse aggregates that meet a specific minimum strength requirement or threshold (e.g., ~ 77 MPa for M95 grade of concrete), which is determined through a priori estimating the cohesion and friction angle of the concrete. The methodology to estimate the cohesion and friction angle from a single unconfined compression test is proposed based on the Mohr–Coulomb theory and using the orientation of failure plane of fractured specimen as a supplemental information from the same experiment. This paper also offers a simple and approximate test procedure to estimate the aggregate's compressive strength (~ 106 MPa in this mix design) reasonably which is essential for the capacity-based mix design. An experimental programme is also carried out to design the concrete mix using the proposed capacity-based approach. The results indicate that M95 concrete is achieved with a low standard deviation and coefficient of variation (~ 3%), falling in class of excellent quality control as per ACI 214R-11. This quality control is crucial in seismic structural design as variations in concrete strength is likely to negate the underlying principle of strong column–weak beam philosophy resulting in the triggering of undesirable shear modes of failure.

Poly(ethylene 2,5-furandicarboxylate) pole figures to determine the microstructural scheme upon uniaxial stretching: Link between orientation and crystallisation

The emergent biobased polymer poly (ethylene 2,5-furandicarboxylate), PEF, has been studied through an innovative approach based on pole figures and orientation factor calculation. PEF uniaxial stretching was performed with different mechanical conditions (different equivalent strain rates), up to several levels of strain and while considering different post-stretching cooling conditions (interrupted, unloaded and ruptured samples). Samples were stretched and interrupted before and after the Natural Draw Ratio (NDR), the deformation for which the material starts strain-hardening. When PEF strain-hardens, it reveals both an increase of the crystalline orientation and crystallinity ratio with the deformation imposed. Unloading the material at temperature tends to decrease partially crystalline orientation, especially regarding the aliphatic part of the chains. Moreover, stretching PEF up to high strains, superior to the NDR, leads to crystal fragmentation. After all, all experimental results were compared to a texture model. It appears that a texture can be developed upon stretching that is close to a fibre texture, as the furan cycles tend to be parallel to the specimen plane.

Mechanical characterisation and high temperature analysis of hyperelastic adhesives – Modelling and experimental validation

Adhesive bonds are subject to multiple environmental conditions that can affect their mechanical performance during service. Therefore, it is important to evaluate the influence of temperature on adhesive strength, as it can impact joint safety and should be considered during the design phase. This study presents an analysis of the effect of high temperatures on the mechanical behaviour of joints made with highly elastic adhesives, specifically a polyurethane and a silicon-modified polymer. Shear and tensile tests were conducted at temperatures of 23, 50, and 80 °C using dumbbell specimens for tensile tests and single lap specimens (SLJ) for shear tests. The tests were performed with two different substrates, aluminium (Al) and glass fibre reinforced polyester panel (GRP), and with varying adhesive thicknesses. These tests aim to assess the impact of temperature conditions on the mechanical properties of the adhesive and the behaviour of the joints. The analysis of the experimental results reveals that the adhesive degrades when exposed to high temperatures, resulting in reduced strength and stiffness, and less linear behaviour.Furthermore, this work involves the determination of a model able to reproduce the mechanical behaviour of hyperelastic adhesive at high temperatures, considering diverse constitutive modelling approaches. To achieve this, a testing protocol was conducted on basic uniaxial and planar specimens. The results indicate that the Ogden N=2 model is the most suitable for representing the non-linear behaviour of the hyperelastic adhesive at high temperatures. In contrast, the Mooney Rivlin model is more suitable to represent the material behaviour under ambient conditions. To conclude this work, the law has been satisfactorily validated by comparing the results of tests carried out on SLJ specimens with different adhesive thicknesses.

Wave Optical Modeling of the SEM Column From Source to Specimen.

Probe formation in scanning electron microscope (SEM) is often reduced to objective lens action modeling based on a point-spread function or Fourier transforms. In this study, we present the first complete wave optical modeling of the whole SEM column based on plane-by-plane propagation of the electron beam wavefunction without simplifying the optical system. We identify the challenges in plane-by-plane beam propagation and show how sampling limitations produce aliased results. Through a careful selection and combination of propagators, we have developed a general wave optical propagation method that is able to overcome the aliasing problem to achieve the appropriate probe widths. Using a two-step propagator, we show that it is possible to model the electron beam distribution throughout the column from the virtual source plane to the specimen plane. We also show that our results from the wave optical simulations are consistent with the geometrical theory of probe formation. Finally, as a direct application of this method, we demonstrated that the combined effect of aberrations in the condenser lens and the probe forming objective lens cannot be accurately represented using only the objective lens. Designing beam shaping experiments and studying the effect of partial coherence can be some novel applications.

A New Approach to Breast Specimen Orientation: Avoiding Pitfalls with the Specimen Plate Concept.

Accurate specimen marking is crucial during breast cancer surgery to avoid misorientation, which can lead to inadequate re-excision and tumor recurrence. We studied the marking methods at various breast cancer centers to create a tool that would prevent specimen misorientation. An online questionnaire was used to survey marking procedures at major breast cancer centers in Hungary, and a tool was developed using a troubleshooting method. Twelve out of twenty units responded (60%). Nine use an institutionally standardized marking system. Less than half of the surgical teams found specimen mammograms to be unambiguous. In more than 70% of departments, pathologists were uncertain about breast specimen orientation. Ambiguous marking methods caused orientation errors in half of the cases, while unclear marking directions caused the rest. Most pathologists (85%) and surgeons (75%) believed that coronal plane specimen mammography would help solve the problem. A plastic specimen plate has been developed to anchor breast tissue to a coronal breast scheme as seen in mammography images, providing clear localization information throughout the surgical process. There is a lack of standardization in breast specimen orientation and marking in Hungary. An optimized orientation toolkit is being developed to ensure consistent interpretation of specimen mammograms by surgeons and pathologists.

Reducing out-of-band radar cross-section of metasurface-based radome composites via beam-scattering mechanism

In this work, a metasurface-based radome composite (MRC) with customized electromagnetic (EM) functions is proposed. By employing a beam-scattering mechanism, high transmission at 2–4 GHz and significant radar cross-section (RCS) reduction at 8–18 GHz are achieved. The MRC prototype features a sandwiched construction and is fabricated using quartz fiber-reinforced composite (QFRC) skins, polymethacrylimide (PMI) foam cores, and silver-based frequency selective surface (FSS) screens. The calculation, simulation, and measured results demonstrated that the transmission of the planar specimen is larger than −1 dB at 2–4 GHz and the RCS reduction is less than −10 dB at 8–18 GHz. The measured results also verified that in the HH and VV polarizations, the mono-static RCS of a square pyramid (SP) specimen at specific directions from 8 GHz to 12 GHz is significantly reduced. It is believed that our finding has great application potential in stealth radome technology.

Stereo-DIC Challenge 1.0 – Rigid Body Motion of a Complex Shape

BackgroundStereo-DIC is a widely used optical measurement technique that provides a dense full-field 3D measurement of the shape, displacement, and strain of a solid sample. When compared with 2D-DIC, Stereo-DIC provides greater flexibility and expands its use beyond flat, planar specimens. Furthermore, the widespread availability of commercial systems has led to the adoption of the technique throughout industry, academia, and government research labs.ObjectiveEven though some research has been done to understand the effects of different experimental and stereo-DIC parameters, no reference is available to benchmark and compare the performance of current stereo-DIC algorithms to each other.MethodsThis paper provides the description and analysis of a carefully controlled 3D experiment and associated images used to compare the results from five subset based DIC software packages. Both the images and analysis codes used in this paper to compare the results are described here and are available for download and use for continued research.ResultsWe show that over a very large range of motion, the 3D errors are very small, less than 80μ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\mu$$\\end{document}m over a travel of ±20 mm out-of-plane and ±20 mm in-plane. While all codes performed similarly, there are important differences noted in the paper.ConclusionThe image sets and results comparison software are hosted by the International DIC Society (www.iDICs.org) and are freely available for download and analysis for comparison with results in this paper. Furthermore, it is hoped that this set of images can be used for future research in improving stereo-DIC by future authors.

Analyzing Pelvic Asymmetry by Sex and Ancestry: Insights From an Osteological Collection.

Pelvic asymmetry has been noted in pelvic imaging, and might influence the development of various spinal pathologies, most notably scoliosis. There is a limited understanding of the relationship between pelvic asymmetry and sex and ancestry, and limited use of 3D modeling. The purpose of this study was to identify pelvic asymmetry and morphology differences between sex and ancestry utilizing 3D modeling on young adults in an osteological collection. Thirty-three osteological pelvic specimens aged 18-25 years (average age 21.4 ± 2.0 years) were scanned to create virtual 3D models for analysis. Pelvic asymmetry and morphology were measured and compared across sex (male and female) and ancestry (European American and African American). Multivariate regression analysis was performed to examine the relationship between the variables measured. Multivariate regression analysis demonstrated statistically significant relationships between innominate-pelvic ring ratio and both sex (p < 0.001) and ancestry (p= 0.003) with larger ratios in male and African American specimens respectively. There was also a statistically significant relationship of greater sacral 1 coronal tilt in European American specimens (p= 0.042). There were no statistically significant differences with sex or ancestry in terms of innominate or sacral asymmetry. Although there are differences in overall pelvic shape between sex and ancestry, there is no relationship between these two variables versus pelvic asymmetry in the axial or sagittal planes in young adult osteological specimens.

Optimizing Interfaces in Laser-Brazed Ceramic-Stainless Steel Joints for Hydrothermal Sensors through Finite-Element Modeling

The development of reliable joining techniques for ceramics and metals is crucial for energy applications, such as fuel cells, nuclear reactors, and high-temperature sensors, most especially for the sealing of hydrothermal sensors to study multiphase flows. However, during one-step active laser brazing it is a serious problem that a high thermal stress concentration can occur at the joint interfaces or on the ceramic side of the joint due to mismatches between the CTEs (coefficients of thermal expansion) and/or elastic constants. The uncontrolled thermal residual stress can lead to cracks and defects in the brazement. In the present work, an elastoplastic finite element method/numerical model was formulated to study the thermal residual stresses developed in the brazement between ceramics and austenitic stainless steel during cooling in active laser brazing. Calculations and comparison experiments were conducted to validate the simulated stress distribution in un-patterned ceramics. Stress analyses were conducted for planar and cylindrical specimen geometries (lab joints) relevant for miniaturized energy sensors. Laser interface patterning was employed to create micro-scale features on ceramic interfaces that reduce thermal stress concentrations. The optimization of the interface designing parameters including hatch size, structure width, pattern depth and metal/ceramic thickness ratio was performed using the Taguchi method with orthogonal arrays. The study suggests that laser interface structuring can modify thermal residual stresses in ceramic-to-metal brazements, thereby increasing the reliability of active brazing joints.

Automated Segmentation and 3D Reconstruction of Different Membranes from Confocal Z-Stacks.

Confocal laser scanning microscopy (CLSM) is an advanced microscopy technique based on fluorescence technology which produces sharp images of a specimen in a single focal plane. The optical sectioning by CLSM allows to have z-stacks which can be further processed into 3D reconstructions. These then provide the option of variable perspectives and additional precise data evaluation on structural and anatomical alterations. Here, we used CLSM to image the thylakoids of cyanobacteria and the endoplasmic reticulum (ER) in moss protonemata as an example. Then, out of the confocal z-stacks, we create 3D constructions of the membranes and their alterations to present a holistic, structural view from different angles.

Evaluation of the mechanical properties of porcine kidney.

With the development of medical diagnosis and treatment, knowing the mechanical properties of living tissues becomes critical. The aim of this study was to investigation material properties of the fresh porcine kidney and the parametric characterization of its viscoelastic material behavior. The material investigation included uniaxial tension tests in different strain rates, relaxation tests, as well as hydrostatic compression tests on the samples extracted from the fresh porcine kidney cortex. Tension tests and relaxation tests were performed by a planar dog-bone specimen with a micron loading testing machine. Hydrostatic compression tests were performed on the kidney cylinder sample which was placed in a compression chamber. Furthermore, a nonlinear viscoelastic model recently proposed by us was employed to characterize the tension data at different strain rates and relaxation test data. The the experimental and numerical results show that the stress-strain relations of the porcine kidney cortex at different strain rates in tension are presented for the first time and a higher strain rate results in higher ultimate strength and initial Young modulus but a lower rupture strain. A damage-dependent visco-elastic model is employed to model the tension data at different strain rates and relaxation data and exhibits a good agreement with the experimental data, which also demonstrates that the damage has an obvious influence on the stress-strain relation. Through comparison with the existing reference covering the uniaxial compression data, it seems that the mechanical behavior of the porcine kidney cortex manifests a stress state-dependent mechanical behavior. The ultimate strength and rupture strain are larger in compression than that in tension.

Design, hardware and software for heat mode control in testing machine for high temperature experiments

A description of the design, control system, and software implementation of the thermal mode control of the experimental creep testing machine developed at the National Technical University "Kharkiv Polytechnic Institute" is given. As a result of testing the automated temperature control system, the main characteristics of the system were established. It was determined that the range of the temperature regulation task is from 0 to 999°С. The working range of heating is from 100 to 500°С. It was established that when the conditions for placing the specimen and ensuring the required thermal insulation of the heating chamber are met, the absolute value of the average temperature adjustment error has a value that does not exceed ±2°С. The root-mean-square value of the adjustment error is no more than ±1.6°С. It was determined that the stability of temperature maintenance depends on the location of the specimen: in the central zone of the chamber, the values of temperature fluctuations are smaller than when the specimen is placed at the bottom. The cycle time of measuring and adjusting the temperature regime is 1.0012 seconds. The power of the heaters is 2x1200 W (in phase switching) and 2x3500 W (in linear mode). The microcontroller used in the system has resources for connecting additional modules and primary converters, which enables expanding the functionality of the system by organizing additional measurement channels. The first results of testing in the study of creep of plane specimens made from aluminum alloys are presented. The character of the creep curve obtained from the strain measurements of the specimens fully corresponds to its classical forms with three sections. A view of a fragment of the destroyed specimen is provided. The modular design, versatility and high technical characteristics of the system and the testing machine as a whole allow its use in various experiments in research projects and in the educational process.

High-resolution chemical and structural characterization of the native oxide scale on a Mg-based alloy

The structure and composition of the native oxide forming on the basal plane (0001) of the magnesium-based alloy Mg-2Al-0.1Ca was investigated by combining scanning transmission electron microscopy (STEM) and atom probe tomography (APT). While STEM measurements demonstrated the growth of a (111) MgO oxide layer with 3–4 nm thickness on the basal (0001) plane of the atom probe specimen, APT data further revealed the formation of an aluminum-rich region between bulk magnesium and the native oxide. The aluminum enrichment of up to ∼20 at% at the interface is consistent with an inward growth of the oxide scale.

Methodology for the mechanical characterisation of hyperelastic adhesives. Experimental validation on joints of different thicknesses

This work focuses on the mechanical characterisation of adhesives with hyperelastic behaviour and on the determination of the behavioural laws that best represent it, in order to introduce them in simulation models. First, a test plan is carried out on simple specimens: uniaxial and planar configuration. These are designed to measure the non-linear behaviour of adhesives in both tensile and pure shear. Unlike the uniaxial specimen, which is governed by a test standard (UNE-ISO 37) that defines its geometry, the planar specimen does not have a standard that defines its dimensions. Therefore, in this research it is proposed to carry out tests with specimens of different width-length sizes to evaluate how these dimensions affect the stress-strain curves.For mechanical characterisation, finite element programs provide the tool to evaluate the predicted behaviour of a hyperelastic material from the experimental results, displaying in the same graph the degree of approximation obtained for the results of each test (Dumbbell and planar) with different hyperelastic models, allowing us to select the hyperelastic model that best fits the experimental data.The Mooney-Rivlin model was found to be the best fitting model and therefore the most appropriate to describe the behaviour of hyperelastic adhesives used in this study. To conclude this study, the obtained law was validated by comparing the results of tests carried out on single lap joint (SLJ) specimens of different thickness.

Experimental study on post-fire mechanical properties and fracture behavior of Q690 steel

Fire is one of the most dangerous disasters for high-strength steel structures. After a fire event, the deterioration of mechanical properties of high-strength steel together with the complex stress state generated by external loading may lead to an unexpected failure or collapse of high-strength steel structures. Therefore, it is very critical to evaluate the post-fire behavior of high-strength steel considering stress state effects. This study conducted a series of tests on the Q690 steel specimens after being exposed to high temperatures ranging from 200 to 1000°C with different cooling methods including air-cooling and water-cooling methods. The tested specimens including smooth round specimens, notched round specimens, and grooved plate specimens were designed to consider the failure mode in axisymmetric stress state and plane strain state. To validate the accuracy of the test results, the mechanical properties such as yield strength, ultimate strength, elastic modulus, and ultimate strain were first compared with other test results reported in the literature. The post-fire ultimate strength under different stress states was obtained directly from the test results. Then, the post-fire equivalent plastic strain at fracture of different specimens was obtained from test data together with the finite element analysis results and analyzed under different stress triaxialities and Lode angle parameters. According to this study, an increase in stress triaxiality can result in an increase in ultimate strength but a decrease in the equivalent plastic strain at fracture for Q690 steel after fire. When the exposed temperature was not higher than 800°C, the post-fire strength of the plane strain specimen (Grooved Plane Specimen) was higher than that of the axisymmetric tension specimen (Notched Round Specimen) under a similar stress triaxiality; however, for their post-fire equivalent plastic strain at fracture, the results were opposite.

Validation of Hypoxia Detection Sequences on the MR Linac

Magnetic resonance linear accelerator (MRL) systems permit acquisition of novel imaging at the time of radiotherapy. A validated MR hypoxia imaging biomarker could select patients for adaptive radiotherapy with hypoxia modification or dose escalation. The aims of this study were (1) to develop a protocol for quantitative hypoxia sensitive MRI (2) to validate these in prostate cancer (PCa) against pimonidazole-stained prostatectomy sections. Blood oxygen level dependent (BOLD), intravoxel incoherent motion (IVIM), oxygen-enhanced (OE) and dynamic contrast enhanced (DCE) MRI were used. Sequences were developed on a diagnostic 1.5 T MR (MRD) and MRL with healthy volunteers and PCa patients. The Hyprogen trial includes men with localized PCa scheduled for prostatectomy. Imaging is acquired twice prior to surgery and oral pimonidazole is taken 8-16 hours before surgery. Whole prostate (WP) and dominant prostatic lesion (DIL) were outlined on T2-weighted (T2W) images and a 'normal prostate' (NP) volume created by subtracting DIL from WP. Contours were applied to parametric maps from the quantitative MRI, with median and IQR extracted. Patient-specific 3D-printed prostate molds were created from WP volumes and used to guide prostate whole organ dissection. Three of 20 patients recruited to date. MRI data were acquired successfully. A personalized prostate mold was produced for each patient and facilitated dissection of the prostatectomy specimen in a matching plane to MRI to validate hypoxia detection of the MR protocol. Correlation with pimonidazole staining is underway. Imaging parameter median values for NP and DIL acquired on MRD and MRL for the first patient are shown (Table 1). The expected differences between NP and DIL for T1 and D are seen and median values for T2* are consistent with reported values in the literature. The MR hypoxia protocol can be acquired safely and is well-tolerated on the MRL. Once validated against pimonidazole staining adaptive radiotherapy protocols will be developed to use this information.

Atom probe tomography using an extreme ultraviolet trigger pulse.

Atom probe tomography (APT) is a powerful materials characterization technique capable of measuring the isotopically resolved three-dimensional (3D) structure of nanoscale specimens with atomic resolution. Modern APT instrumentation most often uses an optical pulse to trigger field ion evaporation-most commonly, the second or third harmonic of a Nd laser is utilized (∼λ = 532 nm or λ = 355 nm). Herein, we describe an APT instrument that utilizes ultrafast extreme ultraviolet (EUV) optical pulses to trigger field ion emission. The EUV light is generated via a commercially available high harmonic generation system based on a noble-gas-filled capillary. The centroid of the EUV spectrum is tunable from around 25eV (λ = 50 nm) to 45eV (λ = 28 nm), dependent on the identity of the gas in the capillary (Xe, Kr, or Ar). EUV pulses are delivered to the APT analysis chamber via a vacuum beamline that was optimized to maximize photon flux at the APT specimen apex while minimizing complexity. We describe the design of the beamline in detail, including the various compromises involved. We characterize the spectrum of the EUV light and its evolution as it propagates through the various optical elements. The EUV focus spot size is measured at the APT specimen plane, and the effects of misalignment are simulated and discussed. The long-term stability of the EUV source has been demonstrated for more than a year. Finally, APT mass spectra are shown, demonstrating the instrument's ability to successfully trigger field ion emission from semiconductors (Si, GaN) and insulating materials (Al2O3).

Specimen plane orientation determination for analysis based on scanning electron microscope: Comparing top-down and side-view approaches.

Many attachments to a scanning electron microscope (SEM), such as energy dispersive x-ray spectroscopy, extend its function significantly. Typically, the application of such attachments requires that the specimen has a planar surface at a specific orientation. It is a challenge to make the plane of a microscale specimen satisfy the orientation requirement since they are visible only in an SEM. An in-situ procedure is needed to adjust specimen orientation by using stage rotation and tilting functions, in the process of which the key is to determine the initial orientation. This study proposed and tested top-down and side-view approaches to determine the orientation of a planar surface inside an SEM. In the top-down one, the projected area is monitored on SEM images as stage rotation and tilt angles are adjusted. When the surface normal is along the electron beam direction, the area has a maximum value. In the side-view approach, the stage is adjusted so that the projection appears to be a straight horizontal line on the SEM image. Once the orientation of the specimen for top-down or side-view observation is determined, the original can be calculated, and a desired orientation can be realized by manipulating the stage. The procedures have been tested by analyzing planar surfaces of spherical particles in Al-Cu-Fe alloy in the form of facets. The measured angles between two surfaces are consistent with those expected from crystallographic consideration within 2.7° and 1.7° for the top-down and side-view approaches, respectively. RESEARCH HIGHLIGHTS: Top-down and side-view approaches have been proposed and tested for in-situ determination of specimen planar surface orientation in a Scanning Electron Microscope. The measured angles between two surfaces are consistent with those expected from crystallographic consideration within 2.7° and 1.7° for the top-down and side-view approaches, respectively.