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A rotation stage was developed to allow the surface of bullet casings to be imaged under ultra-high vacuum (UHV) conditions using time-of-flight secondary ion mass spectrometry (ToF-SIMS). Experiments were performed over a period of seven months to determine how fingermarks deposited on the surface of Webley MkII revolver rounds change over time. Stitching software written in Python was used to combine image strips that were collected by performing ToF-SIMS analysis along the length of the revolver rounds. The ToF-SIMS analysis was performed by analysing a thin strip along the length of the casings, before rotating them through a few degrees and analysing a new strip. This process was repeated until the entire casing had been imaged. The resulting secondary ion images of the fingermarks were compared to optical images obtained from the same and similar rounds that had been exposed to cyanoacrylate fumes and subsequently stained using Basic Yellow 40 (BY40) dye. ToF-SIMS images were shown to display evidence of ridge and sweat pore level detail on samples that displayed no evidence of fingermarks when developed with cyanoacrylate and BY40. The effects of the curvature of the round casings on the morphology of fingermarks were also assessed. ToF SIMS images were compared to marks that had been deposited onto flat paper surfaces using ink. The distortions caused by differences in surface curvature and the deposition methods were found to be within acceptable limits. This journal is

Diffraction-enhanced imaging (DEI) has high sensitivity and a wide dynamic range of density and thus can be used for fine imaging of biological and organic samples that include large differences in density. A fast DEI method composed of continuous fast sample rotations and slow analyzer crystal scanning was developed to shorten the measurement period. Fine sectional images of a biological sample were successfully obtained within a half measurement period of the conventional step-scanning method while keeping the same exposure time. In addition, a fine three-dimensional image of a rat tail was obtained with a 375 s measurement period.

We present a comparison of the rotating magnetocaloric effect (R-MCE) carried out on TmB4, a strongly anisotropic magnetic system, which is based on the determination of the entropy S and entropy change ΔS. Both quantities are determined using independent measurements of the heat capacity and the magnetization as a function of temperature and magnetic field. The comparison of these two approaches shows that estimates of the R-MCE, in particular the estimate of the temperature difference ΔT that occurs during sample rotation in magnetic field H, based on magnetization measurements (which usually present a simpler and faster way to obtain the necessary data) provide similar results to those obtained from detailed temperature dependencies of heat capacity. However, to take the advantage of magnetisation measurements it is necessary to make an approximation concerning heat capacity data. There one has to be careful and use the right approximation for the ΔT estimate. In case of materials with a complex temperature dependence of the heat capacity common approach can lead to significant errors. Our results here suggest for the entropy calculation from magnetic data sets the following procedure: first determine the zero-field (H = 0) contribution to S from heat capacity data, then add to this the magnetic entropy change contribution determined from magnetization measurements.

© 2021 Elsevier B.V. Galling is a category of severe adhesive wear that is defined by surface damage arising between sliding solids, distinguished by macroscopic, usually localized, roughening and creation of protrusions above the original surface. The identification of galling is through a visual observation of the tested surface and is therefore inherently subjective. Due to the microscopic processes behind the onset of galling being poorly understood, further work is needed to understand the behaviour of different materials under galling conditions, both at room temperature and at elevated temperature. The current paper describes the development of a new galling testing apparatus, broadly under the ASTM G196 configuration with the addition of in-situ torque measurements, an automated worm drive for sample rotation as well as band heaters providing capability for testing at elevated temperatures up to a maximum applied stress of 950 MPa. Results from galling tests conducted at room temperate and 300 °C for both Stellite 6 (Co-based) and Tristelle 5183 (Fe-based) hardfacings are presented. The results show that the galling resistance of Tristelle 5183 is significantly reduced at elevated temperature (

A synchrotron-based technique using Compton scattering imaging is presented. This technique has been applied to a coin battery (CR2023), and the cross-sectional image has been obtained in 34 ms without sample rotation. A three-dimensional image of the whole structure has been reconstructed from 74 cross-sectional images taken consecutively by scanning the incident, wide X-ray beam along one direction. This work demonstrates that quick cross-sectional imaging of regions of interest and three-dimensional image reconstruction without sample rotation are feasible using Compton scattering imaging.

In this chapter we show the application of solid state NMR spectroscopy to study active pharmaceutical ingredients (APIs) in different solid forms, as pure components and as parts of more complex systems. The chapter is divided into the sections. After the preface, 2 Very fast MAS solid state NMR , 3 Studies of APIs by means of 2D and 3D very fast MAS solid state NMR techniques present a comprehensive introduction to the modern NMR techniques which are used in structural studies of pharmaceutical products. Techniques employing fast and very fast magic angle spinning with sample rotation over 40 kHz are reviewed. The problem of resolution, sensitivity and N-dimensional NMR is discussed. The application of DNP techniques to study APIs is shown. Section 4 reviews methodologies which are employed to the analysis of structure, polymorphism and molecular dynamics of APIs in the solid state. The NMR crystallography approach for the determination of crystal structure of compounds without or with doubtful X-ray data is reviewed. Section 5 is devoted to the problem of drug delivery systems (DDS) studies. Pharmaceutical cocrystals and salts are discussed in Section 6 . The results presented in this chapter demonstrate that by adjusting the sample spinning speed and selecting dedicated solid state NMR sequences, general and specific problems covering various aspects of drug design and therapeutic applications can be solved, described and explained.

This paper investigates the influence of several noise reduction techniques implemented in sample rotation holographic tomography for the effective utilization of sparse-data for the three-dimensional tomography reconstruction of the samples used.

The surface tension and viscosity of equilibrium and supercooled liquids of Cu50Zr50 were measured in the containerless electromagnetic levitator ISS-EML in the European space laboratory Columbus on board the International Space Station (ISS) under microgravity using high-speed camera recordings. From 1250 K to 1475 K, the surface tension follows the relation σ(T) = (1.58 ± 0.01) N/m – (3.1 ± 0.6) · 10−4 N/m · K · (T – 1209 K). A frequency shift correction was applied to remove the influence of sample rotation on the measured surface tension. Within the investigated temperature range, the viscosity can be expressed by an Arrhenius temperature dependence η(T) = η0 · exp(EA/kBT), with η0 = (0.08 ± 0.02) mPa·s and EA = (0.58 ± 0.03) eV.

Convolutional neural networks (CNNs) have outperformed most state-of-the-art methods in object detection. However, CNNs suffer the difficulty of detecting objects with rotation, because the dataset used to train the CCNs often does not contain sufficient samples with various angles of orientation. In this paper, we propose a novel data-augmentation approach to handle samples with rotation, which utilizes the distribution of the object's orientation without the time-consuming process of rotating the sample images. Firstly, we present an orientation descriptor, named as “principal-axis orientation’’, to describe the orientation of the object's principal axis in an image and estimate the distribution of objects' principal-axis orientations (PODs) of the whole dataset. Secondly, we define a similarity metric to calculate the POD similarity between the training set and an additional dataset, which is built by randomly selecting images from the benchmark ImageNet ILSVRC2012 dataset. Finally, we optimize a cost function to obtain an optimal rotation angle, which indicates the highest POD similarity between the two aforementioned data sets. In order to evaluate our data augmentation method for object detection, experiments, conducted on the benchmark PASCAL VOC2007 dataset, show that with the training set augmented using our method, the average precision (AP) of the Faster RCNN in the TV-monitor is improved by 7.5%. In addition, our experimental results also demonstrate that new samples generated by random rotation are more likely to result in poor performance of object detection.

International audience; Time of flight secondary ion mass spectrometry (ToF-SIMS) is a well-adapted analytical method for the chemical characterization of concentration profiles in layered or multilayered materials. However, under ion beam bombardment, initially smooth material surface becomes morphologically unstable. This leads to abnormal secondary ion yields and depth profile distortions. In this contribution, we explore the surface topography and roughening evolution induced by O-2(+) ion bombardment on GaSb/InAs multilayers. We demonstrate the formation of nanodots and ripples patterning according to the ion beam energy. Since the latter are undesirable for ToF-SIMS analysis, we managed to totally stop their growth by using simultaneously sample rotation and oxygen flooding. This unprecedented coupling between these two latter mechanisms leads to a significant enhancement in depth profiles resolution.

To simulate the wear behavior of the cutting edge of the mining load-haul-dumper bucket, high-stress abrasion laboratory wear tests were conducted and compared to the in-service tests. The effects of test parameters and different abrasives on the wear rates and wear mechanisms of wear resistant steels were studied using the high-speed slurry-pot with a dry abrasive bed (dry-pot) and in the actual in-service use as a cutting edge. The laboratory wear tests produced results that are well comparable with the in-service case observations. Especially at the higher sample rotation speed with granite as an abrasive, the wear rates were quite similar as determined from the cutting edge of a loader bucket that had been used in a mine. submittedVersion acceptedVersion

The method of diffractometry based on the use of synchrotron radiation was used to study the structural transformations occurring in the surface layers of the D16 alloy samples in the course of sliding friction. Information on the defect structure of materials at each sample rotation was obtained in real time. Under the conditions of dry sliding friction, intensive defect accumulation occurs at the initial stage of loading and then the wear process reaches the stable level. Further on, the shape of X-ray line profiles stabilizes, which indicates the equilibrium of competing processes of defect accumulation and relaxation of emerging stresses.

X-ray photoelectron spectroscopy (XPS) was used in conjunction with gas cluster ion source etching to analyze polystyrene and polyvinylpyrrolidone multilayer samples, total thickness ~15 μm, to establish optimal conditions for depth profiles over many μm in depth. Using standard conditions, these samples demonstrate a reduction in depth resolution and sputtering yield, which is shown to be partly due to X-ray–induced damage and partly due to roughening of the sputtered surface. By limiting the X-ray exposure, it was possible to retain depth resolution to a depth of approximately 5 μm; to obtain useful depth profiles beyond this depth, it was necessary to use sample rotation. The use of optimized conditions allowed the chemical integrity of the polymer layers to remain intact during the etching process with relatively sharp interfaces over the full depth of the films. Both the elemental intensities in XPS and the line shape of the C 1s peak could be used to determine the differences in chemical structure of the films in the depth profile. Detailed analysis suggests that a “stepwise” rotation scheme can maintain depth resolution better than continuous rotation during sputtering.

The prior aim of lab testing is the determination of parameters. However, the measurements do not only reflect the rock or soil properties, but contain also, at least to some extent, the influence of the test equipment. Even if measurements are designed to minimize the influence of the test equipment often some measurement values are effected by an unknown amount. Therefore, it is proposed to build detailed numerical models of the test device including the specimen and to duplicate the lab test completely. This paper presents experimental and numerical tests performed with a shear box device. Multi-stage direct shear tests were conducted on smooth plane joints in artificial rock-like material under constant normal loading (CNL) conditions. A 3-dimensional numerical model of the shear box device including the sample was built and the laboratory tests were simulated. The numerical model comprises the loading frame, the hydraulic pistons, the shear boxes and the sample and considers the measuring devices. The numerical model was able to reproduce the non-uniform stress distribution at the joint connected with sample rotation, which in turn produces unwanted frictional forces at the upper shear box. Consequently, only 91–94% of the applied and measured normal force really acts at the joint. Moreover, numerical simulations also shows, to what extend the different parts of the loading frame deform.

Resumen Las técnicas de medición por ensayos no destructivos han demostrado ser una poderosa herramienta en el estudio y caracterización de materiales. Este trabajo presenta el desarrollo de un sistema automatizado para la medición de la atenuación de radiación gamma en los materiales. Primero, se describe el proceso de diseño de los elementos electromecánicos y el sistema de control automático, seguido de su implementación. Los resultados muestran la capacidad y precisión mecánica obtenidas para el sistema desarrollado. En particular la resolución del motor y capacidad de recorrido del robot son respectivamente de 8 μm para el movimiento horizontal con un movimiento de hasta 54 cm bidireccional y 4 μm para el movimiento vertical con un movimiento de hasta 57 cm bidireccional. Además, el sistema permite una rotación de las muestras con un recorrido de 360° unidireccional. Se comprueba estadísticamente la sensibilidad del sistema para detectar cambios locales en el espesor del material, evaluando los periodos de muestreo para obtener una medición con precisión. Se determina el error relativo de las mediciones, analizando posibles causas y soluciones. Abstract Non-destructive testing techniques have proven to be a powerful tool in the study and characterization of materials. This work presents the development of an automated measurement system based on the attenuation of gamma radiation for the study of materials. First, we described the design process of the electromechanical elements and the automatic control system, followed by its implementation. The results show the capacity and mechanical accuracy of the system. The resolution of the motor and the displacement capacity of the robot are 8 μm for the horizontal movement with maximum carriage travel of bi-directional 54 cm and 4 μm for vertical movement, with maximum carriage travel of bi-directional 57 cm. The system allows for a sample rotation, being the angular trajectory of 360 ° with unidirectional travel. The sensitivity of the system for detecting specific changes in the thickness of the material is verified statistically, also evaluating the sampling periods to obtain a measurement with precision. The relative error of the measurements is determined and its causes and solutions are discussed.

Piezo-driven rotator is convenient for tilted magnetic field experiments due to its precise angle control. However, the rotator itself and the sample mounted on it are difficult to be cooled down because of extra heat leaks and presumably bad thermal contacts from the piezo. Here, we report a piezo-driven sample rotation system designed for ultra-low temperature environment. The sample, as well as the rotating sample holder, can be cooled to as low as 25 mK by customized thermal links and thermal contacts. More importantly, the electron temperature in the electrical transport measurements can also be cooled down to 25 mK with the help of home-made filters. To demonstrate the application of our rotation system at ultra-low electron temperature, a measurement revealing tilt-induced localization and delocalization in the second Landau level of two-dimensional electron gas is provided., Comment: 22 pages, 6 figures

We have performed secondary ion mass spectrometry depth profiling analysis of III–V based hetero-structures at different target temperatures and found that both the surface segregation and surface roughness caused by ion sputtering can be radically reduced if the sample temperature is lowered to −150 °C. The depth profiling of ‘frozen’ samples can be a good alternative to sample rotation and oxygen flooding used for ultra-low-energy depth profiling of compound semiconductors. Copyright © 2016 John Wiley & Sons, Ltd.

Precise sample orientation is crucial for microscopy but is often performed with macroscopic tools and low accuracy. In vivo imaging of growing and developing samples even requires dynamic adaptation of the sample orientation to continuously achieve optimal imaging. Here, we present a method for freely positioning a sample in 3D by introducing magnetic beads and applying a magnetic field. We demonstrate magnetic orientation of fixed mouse embryos and artemia, and live zebrafish embryos and larvae on an epi-fluorescence microscope and on a light-sheet system for optimal imaging.

Traditional Japanese fabrics (Nishijin weave, Kyoto) make a striking visual impression that can be dramatically affected by the reflection of light from the surface of the fabric. The characterization method was developed by using a goniospectrophotometric system while the fabrics were rotated. After comparing the contrast values calculated under the various combination of illumination (θ i) and viewing angles (θ v), the optimum value for θ i/θ v was found to be 45/–70. Using these values, unique patterns of the CIELAB L* component were observed as functions of the sample rotation angle (θω). The shape of L* with respect to θω was found to be affected by the differences in constituent yarn color and weave structure. θω was found to be the most accurate parameter for determining the change in lightness from shiny to dull in the visual assessment.

A precise measurement of graphene thickness is required for the design and development of nano-devices based on the material. Many factors affect this measurement when using scanning tunneling microscope (STM) and atomic force microscope (AFM), including the interaction between the scanning tip and ripples on graphene; such effects have not previously been explored. To investigate this, we measure the sample rotation angle dependence of graphene thickness as determined by contact mode and tapping mode AFM. The graphene thickness as determined by contact mode AFM follows a cosine modulus function of sample rotation angle, while tapping mode AFM reveals a constant graphene thickness, independent of sample rotation angle. For comparison, the AFM torsion signal is measured and follows a sine function of the sample rotation angle. All the measured sample rotation angle dependences can be explained by the interaction between linearly aligned ripples on graphene and the AFM tip in contact with the graphene.

In vivo imaging of growing and developing samples requires a dynamic adaptation of the sample orientation to continuously achieve optimal performance. Here, we present how, after the injection of magnetic beads, a sample can be freely positioned by applying a magnetic field. We demonstrate its performance for zebrafish on an epi-fluorescence microscope and on a light sheet system for superior multi-view acquisition.