Three-dimensional Transmission Electron Microscopy observations of mesopores in dealuminated zeolite Y**

Supported by NWO under grant 98037. The research of AJK has been made possible by a fellowship of the Royal Netherlands Academy of Arts and Sciences (KNAW). The authors thank J.E.M.J. Raaymakers for the nitrogen physisorption measurements, A.J.M. Mens for the XPS measurements, J.A.R. van Veen and E.J. Creyghton for physical data and useful discussions and Shell International Chemicals and Zeolyst for the samples

Three-Dimensional Transmission Electron Microscopy: A Novel Imaging and Characterization Technique with Nanometer Scale Resolution for Materials Science

Three-dimensional transmission electron microscopy (3D-TEM), effectuated by multiple imaging of a sample combined with image analysis, offers a new approach in materials science to obtain 3D information of complex solid materials. Here we report first-of-its-kind results that have been obtained with zeolite materials. Virtual cross-sections and volume rendering of the 3D reconstruction of a metal/zeolite crystal (Ag/NaY) give unequivocal information on the location of the silver particles (10-40 nm in diameter). Virtual cross-sections of the 3D reconstruction of an acid-leached mordenite show the three-dimensional mesoporous channel system (3-20 nm in diameter) with a clarity and definition not seen before

High-precision determination of residual stress of polycrystalline coatings using optimised XRD-sin2ψ technique

The aim of the research is to optimise the XRD-sin2ψ technique in order to perform high precision measurement of surface residual stress. Residual stresses existing in most hard coatings have significant influence on the adhesion, mechanical properties and tribological performance. In the XRD-sin2ψ stress measurement, the residual stress value is determined through a linear regression between two parameters derived from experimentally measured diffraction angle (2θ). Thus, the precision coefficient (R2) of the linear regression reflects the accuracy of the stress measurement, which depends strongly on how precise the 2θ values are measured out of a group of very broad diffraction peaks. In this research, XRD experiments were conducted on a number of samples, including an electron beam evaporated ZrO2 based thermal barrier coating, several magnetron sputtered transitionmetal nitride coatings, and shot-peened superalloy components. In each case, the diffraction peak position was determined using different methods, namely, the maximum intensity (Imax) method, the middle point of half maximum (MPHM) intensity method, the gravity centre method, and the parabolic approaching method. The results reveal that the R2 values varied between 0.25 and 0.99, depending on both the tested materials and the method of the 2θ value determination. The parabolic approaching method showed the best linear regression with R2=0.93±0.07, leading to high precision of the determined residual stress value in all cases; both the MPHM (R2=0.86±0.16) and gravity centre (R2=0.91±0.11) methods also gave good results in most cases; and the Imax method (R2=0.71±0.27) exhibited substantial uncertainty depending on the nature of individual XRD scans

Development and Application of 3-Dimensional Transmission Electron Microscopy (3D-TEM) for the Characterization of Metal-Zeolite Catalyst Systems

With electron tomography (3D-TEM) a 3D-reconstruction is calculated from a series of TEM images taken at a tilt angle range (tilting range) of +70° to -70°. The reconstruction can be visualized with contour surfaces that give information about the surface of the sample as well as with slices through the reconstruction that give detailed information on the interior of the sample. Electron tomography gives much more information than Scanning Electron Microscopy (SEM), since SEM gives only information about the surface of a sample. As a case study, the imaging of silver clusters on zeolite NaY is given. The reconstruction shows silver particles at the external surface as well as a silver particle in a mesopore of the zeolite crystallite. It is concluded that 3D-TEM comprises a breakthrough in the characterization of nano-structured solid catalysts

Black carbon as an additional indicator of the adverse health effects of airborne particles compared with PM10 and PM2.5.

Current air quality standards for particulate matter (PM) use the PM mass concentration [PM with aerodynamic diameters ≤ 10 μm (PM(10)) or ≤ 2.5 μm (PM(2.5))] as a metric. It has been suggested that particles from combustion sources are more relevant to human health than are particles from other sources, but the impact of policies directed at reducing PM from combustion processes is usually relatively small when effects are estimated for a reduction in the total mass concentration

Musculoskeletal complaints and disability in a group of young adults with major congenital upper limb differences in The Netherlands

Purpose: To determine prevalence of musculoskeletal complaints (MSCs) in adults with major congenital upper limb differences (CoULD) compared to able-bodied controls, and to examine associations of MSCs and disability with various biopsychosocial factors. Materials and methods: Questionnaire-based cross-sectional study assessing MSCs, disability (using the Disabilities of the Arm, Shoulder and Hand questionnaire (DASH)), general and mental health status, physical work demands, and upper extremity range of motion. Results: Seventy-one individuals with CoULD (participation rate: 41%) and 71 controls matched on age, gender, and education were included (49% female, mean age 28.9 years). Year prevalence of MSCs was significantly higher in the CoULD group (35%) than in the control group (18%). The CoULD group was less often employed and had lower scores on all measures of upper limb range of motion and hand grip. MSCs were associated with higher DASH scores and higher reported work demands. Disability was associated with female gender, more joints with limited range of motion, unemployment, and lower general and mental health. Factors associated with disability did not differ between groups.Conclusions: MSCs are a frequent problem in young adults with major CoULD. To prevent or reduce MSC and disability, clinicians and researchers should be aware of the associated factors. Implications for rehabilitation The year prevalence of musculoskeletal complaints (MSCs) in those with major congenital upper limb differences (CoULD) was approximately double to that of the control group, implying a potential relationship between CoULD and MSCs. Rehabilitation professionals should develop personalized strategies to manage work demands in those with CoULD, considering the association between MSCs and higher reported work demands. Recognizing the impact of a negatively perceived body image on mental health, clinicians should integrate psychological counseling into rehabilitation treatments to support mental well-being and improve overall quality of life in those with CoULD. Rehabilitation professionals should educate individuals with CoULD about the potential associations between upper limb work demands, MSCs, and disability.</p