Volume 39(1) - Winter 2023

Measurement and analysis software is the crucial interface between the user and an analyzer. Its ease of operation affects how efficiently users achieve their goals. In pursuit of better usability and improved functionality, Rigaku has developed a new measurement and analysis program called “Vullios.”

Discovery of thermal storage materials that can utilize low-temperature waste heat

We have discovered that layered manganese dioxide (birnessite, δ-MnO₂) can store/release heat through an intercalation mechanism in which water molecules in a moist atmosphere are deintercalated/intercalated between the layers. The material has been found to have an excellent balance of various properties required for thermal storage materials, such as low heat-storage temperature, high thermal energy density, good charge/discharge rate, and cyclic properties. In this note, the high-temperature stability of layered manganese dioxide and the crystal structure change accompanying intercalation/deintercalation of water molecules are analyzed by in-situ X-ray diffraction measurements, and its thermal storage properties are evaluated by thermogravimetric differential thermal analysis and differential scanning calorimetry.

3D ED/microED has been attracting much attention because it enables structure analysis of crystals smaller than 1 μm. In this article, examples of crystal structure analysis and some applications of MicroED/3D ED will be presented.

Despite increasing demand for 3D ED/MicroED, measurement and analysis with this analytical technique has not been straightforward. Until recently, electron diffraction experiments were performed mainly as a function of general-purpose transmission electron microscopes. The hurdles were higher than those for X-ray structural analysis because it required an expert in electron microscopy to determine the optimal setting of the equipment for diffraction experiments. To address this situation, Rigaku and JEOL jointly developed an electron diffraction platform dedicated to 3D ED/ MicroED. The system is called XtaLAB Synergy-ED. With the Synergy-ED, anyone can easily perform electron diffraction experiments.

X-ray solution scattering experiments have been utilized to analyze structures and conformational changes of biological macromolecules. Those experiments employ X-ray scattering data in a small-angle region, a technique called Small Angle X-ray Scattering (SAXS). SAXS experiments often focus on the macroscopic shapes and sizes of molecules. However, in principle, the scattering data in the higher scattering angle region contains more detailed structural information. For example, scattering data corresponding to q values (=4π sin θ/λ) between 0.30 and 0.65 Å⁻¹ reflects distances among domains, secondary structure modules, and/or adjunct chemical groups in Antibody–Drug Conjugates (ADCs). These Middle Angle X-ray Scattering (MAXS) experiments should give us a novel picture of complex molecular behaviors, as well as conformational changes in flexible biomolecules. In this article, we will discuss solution structure analysis of human Immunoglobulin G (IgG) by MAXS that revealed significant differences between the solution and crystalline states, as well as a novel observation of its flexibility.

In the past, total scattering data was used to obtain the pair distribution function (PDF) G(r). However, it has become clear that it is also possible to calculate characteristic values related to the physical properties of materials from the total scattering data. In this paper, we introduce two applications using total scattering data. The first evaluates the atomic density of materials using total scattering data. The atomic density of SiO₂ glass obtained by applying the proposed method is consistent within 5% of the literature value. The other is a new application of the Reverse Monte- Carlo (RMC) method for non-crystalline materials. It does not require any additional parameters to calculate diffraction peaks. The proposed method is used to identify specific features of the MnO₆ octahedra of the spinel lithium manganese oxide (LiMn₂O₄) corresponding to each Mn valence.

Helium gas is becoming more difficult to obtain these days due to decreased supply and increased demand. In X-ray fluorescence analysis, helium gas is often used in the analysis of liquid samples, while processing samples as solids is possible under a vacuum. In this article we introduce two liquid sample processing methods for measurements under a vacuum: the droplet method and the oil solidification method. In the droplet method a solution sample is dropped onto a filter paper and dried, and in the oil solidification method an oil sample is mixed with a solidifying agent and solidified.

NEX CG II is a multi-element, multi-purpose energy dispersive X-ray fluorescence (EDXRF) spectrometer that performs rapid qualitative and quantitative trace elemental analyses and addresses needs across many industries. This next-generation, high-end spectrometer is ideal for trace heavy metal and halogen analysis, which is in increasing demand for several sectors. These capabilities make NEX CG II especially well-suited for trace element analysis for environmental monitoring, industrial waste applications, recycled materials, electronic components, pharmaceutical materials, cosmetics, and many others.

This article describes the principles and applications of iterative reconstruction in X-ray computed tomography. We use several real examples to show how iterative reconstruction can produce higher-quality reconstructed images than the conventional reconstruction method.

This article describes the principles and applications of iterative reconstruction (IR) methods. Section 2 describes the procedure of obtaining projection images and notes some important precautions for CT measurements. Principles of conventional reconstruction algorithms are shown in section 3. The principles and features of the IR method are described in section 4. Finally, section 5 showcases situations where IR works well while the conventional reconstruction method struggles.

MILabs B.V. (Headquarters: The Netherlands, hereinafter MILabs), which joined the Rigaku Group in August 2021, is a leading global manufacturer of preclinical imaging systems. Preclinical research, as the name suggests, is a crucial step in the drug discovery process that usually uses mice and rats in advance of clinical trials on human. In preclinical research, efficacy, safety or toxicity of the drug candidates is assessed on living (in vivo) small animals, while visualization of experimental results allows researchers to comprehend how a drug works in organs or the full body with the help of imaging systems. MILabs provides such imaging systems with best-in-class accuracy, sensitivity and efficiency by virtue of developing its proprietary technologies, one of which being cylindrical multipinholes collimators.