A Development of Dynamic Deforming Algorithms for 3D Shape Modeling with Generation of Interactive Force Sensation

PROCEEDINGS OF IEEE VIRTUAL REALITY ANNUAL INTERNATIONAL SYMPOSIU

Compressive residual stress applied to a low-carbon steel surface alloyed with WC tool constituent elements according to friction stir processing

Yamamoto H., Yamamoto Y., Ito K., et al. Compressive residual stress applied to a low-carbon steel surface alloyed with WC tool constituent elements according to friction stir processing. Materials and Design 244, 113225 (2024); https://doi.org/10.1016/j.matdes.2024.113225.Friction stir processing (FSP) effectively improves the fatigue strength of arc-welded joints; however, wear of tools is inevitable in case of high-strength materials. Notably, a new benefit has been discovered: compressive residual stress is applied on the FSPed steel surface, alloyed with the WC tool constituent elements, contrasting with the tensile residual stress typically applied via conventional FSP. To elucidate the mechanism of compressive residual stress application, FSP was performed on a low-carbon steel plate at various rotational speeds. The alloyed topmost layers in the stir zone comprised martensite structures with a small amount of retained austenite grains, resulting in a hardness increase owing to the tool constituent elements. The residual stresses on the stir zone surface were influenced by the alloying contents and the corresponding martensite start temperature (Ms). Compressive residual stresses were maximized at an Ms of approximately 150 °C owing to martensitic transformation expansion near room temperature. Lowering the Ms below approximately 150 °C led to tensile residual stresses and an increased volume fraction of the retained austenite, suggesting that martensitic transformation expansion is insufficient to apply compressive residual stress. Conversely, the retained austenite can resist plastic deformation and crack propagation through deformation-induced martensitic transformation, thereby enhancing fatigue properties

Switching between intramolecular charge transfer and excimer emissions in solids based on aryl-modified ethynyl-o-carboranes

Because of its unique electronic properties, o-carborane has attracted attention as a scaffold for constructing solid-state luminescent materials. Here, we report stimulus-responsive luminochromic materials based on polycyclic aromatic hydrocarbon (PAH), such as anthracene and pyrene, modified with the ethynyl-o-carborane unit. Initially, luminochromism originating from switching of different emission mechanisms is described between intramolecular charge transfer (ICT) emission and excimer emission triggered by mechanical stimuli, heat, and vapor annealing regarding the single o-carborane-substituted anthracene. Next, the luminescence properties of two ethynyl-o-carboranes at both ends of PAHs are presented. In particular, multi-step mechanochromic luminescence of the pyrene derivative is explained. Stepwisely changes triggered by weak stimuli that can induce cracking sites, followed by luminochromic behavior and by grinding treatment, which causes phase transition from crystal to amorphous, leading to luminescent mechanism changes from ICT emission to excimer emission

Time-Dependent Emission Enhancement of the Ethynylpyrene-o-Carborane Dyad and Its Application as a Luminescent Color Sensor for Evaluating Water Contents in Organic Solvents

The time‐dependent emission enhancement (TDEE) phenomena of the 1‐(o‐carboran‐1‐yl)ethynylpyrene dyad were reported. It was found that the emission intensity from the dyad increased in tetrahydrofuran (THF), acetone and dichloromethane with increasing incubation time. From the mechanistic studies, it was suggested that agglomeration of the dyad gradually proceeded in these media, followed by expression of excimer luminescence. Additionally, it was shown that the rates of TDEE of the dyad were sensitively accelerated in the presence of a trace amount of water. Based on this fact, a detection system for water contents in acetone was constructed. Before and after incubation for 96 h at room temperature, time courses of changes in optical properties were monitored. Finally, water contents in acetone can be estimated by the degrees of TDEE and emission color changes in the range from 0.1 wt % to 2.0 wt % and from 2.0 wt % to 20 wt %, respectively

Percutaneous Curettage and Continuous Irrigation for MRSA Lumbar Spondylodiscitis: A Report of Three Cases

There has been a recent increase in pyogenic spondylitis caused by methicillin-resistant Staphylococcus aureus (MRSA) associated with an increasing number of compromised patients. As long as serious paralysis is absent, we recommend percutaneous curettage and continuous irrigation as an effective treatment for MRSA lumbar spondylodiscitis. Under local anesthesia, the affected lumbar discs were curetted using percutaneous nucleotomy, and tubes were placed for continuous irrigation. The period of continuous irrigation was generally 2 weeks. Infection was controlled after one procedure in two cases and after two procedures in one case. Postoperative radiography and magnetic resonance imaging (MRI) showed callus formation, normalized signal intensity in vertebral bodies, and regression of abscesses. Open surgery under general anesthesia has been considered risky in patients with poor performance status or old age. The present method, which is an application of needle biopsy, can be performed under local anesthesia and is minimally invasive

Isotopic analysis of Ni, Cu, and Zn in freshwater for source identification

Nickel (Ni), copper (Cu), and zinc (Zn) are commonly used in human activities and pollute aquatic environments including rivers and oceans. Recently, Ni, Cu, and Zn isotope ratios have been measured to identify their sources and cycles in environments. We precisely determined the Ni, Cu, and Zn isotope ratios in rain, snow, and rime collected from Uji City and Mt. Kajigamori in Japan, and investigated the potential of isotopic ratios as tracers of anthropogenic materials. The isotope and elemental ratios suggested that road dust is the main source of Cu in most rain, snow, and rime samples and that some of the Cu may originate from fossil fuel combustion. Zinc in the rain, snow, and rime samples may be partially attributed to Zn in road dust. Zinc isotope ratios in the Uji rain samples are lower than those in the road dust, which would be emitted via high temperature processes. Nickel isotope ratios are correlated with V/Ni ratios in the rain, snow, and rime samples, suggesting that their main source is heavy oil combustion. Furthermore, we analyzed water samples from the Uji and Tawara Rivers and the Kakita River spring in Japan. Nickel and Cu isotope ratios in the river water samples were significantly heavier than those in rain, snow, and rime samples, while Zn isotope ratios were similar. This is attributed to isotopic fractionation of Cu and Ni between particulate-dissolved phases in river water or soil

Neuronal densities and vascular pathology in the hippocampal formation in CADASIL

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is the most common form of hereditary cerebral small vessel disease. Previous neuroimaging studies have suggested loss of hippocampal volume is a pathway for cognitive impairment in CADASIL. We used unbiased stereological methods to estimate SMI32-positive and total numbers and volumes of neurons in the hippocampal formation of 12 patients with CADASIL and similar age controls (young controls) and older controls. We found densities of SMI32-positive neurons in the entorhinal cortex, layer V, and cornu ammonis CA2 regions were reduced by 26%-50% in patients with CADASIL compared with young controls (p = CADASIL. These changes were not explained by any hippocampal infarct or vascular pathology or glial changes. Our results suggest notable loss of subsets of projection neurons within the hippocampal formation that may contribute to certain memory deficits in CADASIL, which is purely a vascular disease. It is likely that the severe arteriopathy leads to white matter damage which disconnects corticocortical and subcortical-cortical networks including the hippocampal formation. (C) 2020 The Authors. Published by ELSEVIER