Tangential bond stiffness evaluation of adhesive lap joints by spectral interference of the low-frequency A0 lamb wave

Transmission spectra of the lowest-order antisymmetric (A0) Lamb wave for adhesively bonded single lap joints are experimentally investigated in a frequency range below 0.4 MHz. Based on the theoretical results of the wave interference, a tangential bond stiffness evaluation method is proposed for the lap joints. Aluminum alloy plates bonded with epoxy adhesive on different conditions were prepared as bonded specimens. An air-coupled ultrasonic transducer was used to generate the A0 mode in the specimens, and the signals of the transmitted waves across the joints were measured with a pin-type piezoelectric transducer. Spectral analysis was performed for the measured waveforms, and the transmission coefficient was calculated for each specimen as a function of frequency. The experimental results showed that the transmission coefficient has local maxima and minima at multiple frequencies, called peak and notch frequencies, respectively. The sets of the peak and notch frequencies were different among the bonded specimens. Based on the peak and notch frequencies, the tangential bond stiffness was estimated for each bonded specimen. As a result, the bond stiffnesses obtained for the specimens with the same nominal bond thickness and adherend pretreatment were almost equal even if the bond lengths were different. Furthermore, the evaluation results showed that pretreatments such as sanding and contamination of adherend surfaces affect the bond stiffness due to the change in the interfacial stiffness.Naoki Mori, Daichi Wakabayashi, Takahiro Hayashi, Tangential bond stiffness evaluation of adhesive lap joints by spectral interference of the low-frequency A0 lamb wave, International Journal of Adhesion and Adhesives, Volume 113, 2022, 103071, https://doi.org/10.1016/j.ijadhadh.2021.103071

Fatty Acid Accumulation and Resulting PPARα Activation in Fibroblasts due to Trifunctional Protein Deficiency

To examine fatty acid accumulation and its toxic effects in cells, we analyzed skin fibroblasts from six patients with mitochondrial trifunctional protein deficiency, who had abnormalities in the second through fourth reactions in fatty acid β-oxidation system. We found free fatty acid accumulation, enhanced three acyl-CoA dehydrogenases, catalyzing the first reaction in the β-oxidation system and being assumed to have normal activities in these patients, and PPARα activation that was confirmed in the experiments using MK886, a PPARα specific antagonist and fenofibrate, a PPARα specific agonist. These novel findings suggest that the fatty acid accumulation and the resulting PPARα activation are major causes of the increase in the β-oxidation ability as probable compensation for fatty acid metabolism in the patients' fibroblasts, and that enhanced cell proliferation and increased oxidative stress due to the PPARα activation relate to the development of specific clinical features such as hypertrophic cardiomyopathy, slight hepatomegaly, and skeletal myopathy. Additionally, significant suppression of the PPARα activation by means of MK886 treatment is assumed to provide a new method of treating this deficiency

Theoretical study on novel electronic properties in nanographite materials

Antiferromagnetism in stacked nanographite is investigated with using the Hubbard-type model. We find that the open shell electronic structure can be an origin of the decreasing magnetic moment with the decrease of the inter-graphene distance, as experiments on adsorption of molecules suggest. Next, possible charge-separated states are considered using the extended Hubbard model with nearest-neighbor interactions. The charge-polarized state could appear, when a static electric field is present in the graphene plane for example. Finally, superperiodic patterns with a long distance in a nanographene sheet observed by STM are discussed in terms of the interference of electronic wave functions with a static linear potential theoretically. In the analysis by the k-p model, the oscillation period decreases spatially in agreement with experiments.Comment: 8 pages; 6 figures; accepted for publication in J. Phys. Chem. Solids; related Web site: http://staff.aist.go.jp/k.harigaya/index_E.htm

GROUND PENETRATING RADAR DATA INTERPRETATION USING ELECTROMAGNETIC FIELD ANALYSIS FOR SEA ICE THICKNESS MEASUREMENT

Observation of sea ice thickness by remote sensing is one of key issues to understand an effect of global warming. However, ground truth must be necessary to discuss this kind of approach. Although there are several methods to acquire ice thickness, Ground Penetrating Radar (GPR) can be good solution because it can discriminate snow-ice and ice-sea water interface thanks to comparative higher spatial resolution than the other methods. In this paper, we carried out GPR measurement in brackish lake and an electromagnetic field analysis in order to interpret the GPR data. The simulation model was assumed considering the actual snow and ice thickness acquired in field measurement. From the simulation results, although it seems difficult to identify the reflection at snow and ice interface due to a thin layer thickness and a low dielectric constant, snow and ice thickness may be estimated by using multiple reflection components

Tumor Induction by Azoxymethane (AOM) and 2-Amino-l-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) in F344 Rat Gastric Mucosa Featuring Intestinal Metaplasia Caused by X-irradiation

Male F344 5-week-old rats were X-irradiated, and 16 weeks after the first dose. azoxymethane (AOM) was injected or 2-amino-l-methyl-6-phenylimidazo [4,5-b]pyridine (PhIP) was given by intragastric intubation. Tumors in the pylorus of the glandular stomach were observed in 4 out of the 29 animals receiving X-rays + AOM and in 4 out of the 25 animals receiving X-rays + PhIP, 12 months after administration. No such lesions were found in the chemical or X-ray alone groups. Intestinal metaplasia and some induced tumors were positive for CDX2. It was concluded that the presence of intestinal metaplasia may increase sensitivity to the induction of gastric tumors by colon carcinogens

Construction of Eco-system for NTBFs to Thrive, Grow and Agglomerate (Japanese)

Boston, Massachusetts in the U.S. was able to rejuvenate its economy after WWП through the thrift, growth and agglomeration of MIT-born New Technology-based Firms (NTBFs), which have been categorized as the origin of new venture firms. This paper will explain why some areas like Boston, Silicon Valley, and Austin TX in the U.S. and Cambridge in the UK, were able to construct successful Eco-systems for NTBFs to thrive, grow and agglomerate, while others were unsuccessful, by applying the Eco-system Construction Model deducted from previous studies. Based on the research findings of this paper, we also outline our recommendations for a revision of the U.S. innovation model by clarifying its advantages and disadvantages. The U.S. model was introduced in Japan at the end of the 1990s and prompted a number of new innovation policy projects including the '1000 University Start-up Venture Scheme', the 'Industrial Cluster Project' and the 'Knowledge Cluster Initiative.'

Via-switch FPGA with transistor-free programmability enabling energy-efficient near-memory parallel computation

We are developing field-programmable gate arrays (FPGAs) with a new non-volatile switch called via-switch. In via-switch FPGAs (VS-FPGAs), the via-switches required for reconfiguration are placed in the routing layer so that the entire transistor layer can be utilized for computing, and higher implementation density can be achieved compared to conventional SRAM FPGAs. Furthermore, since arithmetic units and memories for computing can be placed under the via-switch crossbar for routing, large-scale parallel operations can be realized where the memory and the arithmetic unit are adjacent to each other. These features enable operation with high energy efficiency. This article reports 65 nm prototype fabrication results and predicted the performance of the VS-FPGA designed for AI applications. We also present the developed application mapping flow and crossbar programming method. The VS-FPGA closes the gap between FPGA and application-specific integrated circuits (ASIC) with the performance advantage of the via-switch and via-switch copy scheme for FPGA-to-ASIC migration, contributing to the expansion of the FPGA usage

Successful Endoscopic Injection Sclerotherapy of High-Risk Gastroesophageal Varices in a Cirrhotic Patient with Hemophilia A

A 68-year-old man with hemophilia A and liver cirrhosis caused by hepatitis C virus was referred to our hospital to receive prophylactic endoscopic treatment for gastroesophageal varices (GOV). He had large, tense, and winding esophageal varices (EV) with cherry red spots extending down to lesser curve, predicting the likelihood of bleeding. Esophageal endoscopic injection sclerotherapy (EIS) was performed with a total 15 mL of 5% ethanolamine oleate with iopamidol (EOI). Radiographic imaging during EIS demonstrated that 5% EOI reached the afferent vein of the varices. He was administered sufficient factor VIII concentrate before and after EIS to prevent massive bleeding from the varices. Seven days after EIS, upper gastrointestinal endoscopy (UGIE) showed that the varices were eradicated almost completely. Eighteen months after EIS, the varices continued to diminish. We report a successful case of safe and effective EIS for GOV in a high-risk cirrhotic patient with hemophilia A

Long-term survival with RAS-associated autoimmune leukoproliferative disorder with somatic KRAS mutation:A case report

　RAS -associated autoimmune leukoproliferative disorder (RALD) is a recently reported rare nonmalignant autoimmune disorder. The characteristic clinical findings of RALD include monocytosis, leukocytosis, lymphoproliferation, and autoimmune phenomena. RALD is defined by somatic mutations in KRAS or NRAS . It is a new disease that was reported by Niemela and Takagi in 2011. The prognosis and incidence are currently unknown and the treatment strategy has not yet been established.　Here we describe the long-term survival of a patient with who displayed a somatic KRAS G12D mutation. His clinical features and labolatory data were overlapped with juvenile myelomonocytic leukemia and chronic myelomonocytic leukemia. Mercaptopurine hydrate, hydroxycarbamide and azacitizine were administered to control white blood cell count and improve clinical symptoms. He had a long survival time without hematopoietic stem cell transplantation