パーティクル・ボードに関する研究 : (第6報)含脂率およびパーティクル・ディメンションが低比重ボードの材質におよぼす影響について

この論文は国立情報学研究所の学術雑誌公開支援事業により電子化されました

Application of Fracture Mechanics to Strength Analysis of Glued Lap Joints

この論文は国立情報学研究所の学術雑誌公開支援事業により電子化されました。Strength of double lap joints of wood (Lawson cypress) including a glued end butt joint at center was analyzed by applying Fracture Mechanics. Approximate stress analysis was conducted in accordance with Volkersen type theory. Apparent strain energy release rate G^* of the joints was derived from applying the J-integral to the stress components. It was assumed that the apparent strain energy release rate G^* of the joints was propotional to the strain energy release rate G of cracked adhesive joint specimen subjecting to shear force and expressed as G^*=NG. Fracture criterion was assumed that when G^* reached its critical value G^*_c (=NG_C), fracture occured at the right-angled corner of the joints. Experimental results showed good applicability of derived equation on predicting strength of the joints when N was 0.5 and G_c was 0.25 kg・cm/cm^2. A simple but conservative design equation between strength and the half lap length of the joints based on the experimental results and derived equation was proposed

Estimating Fracture Toughness from Nonlinear Load-Deflection Relation

この論文は国立情報学研究所の学術雑誌公開支援事業により電子化されました。Load- deflection relation of Double Cantilever Beam (DCB) specimens with thick epoxy adhesive layer was analyzed by assuming adherends to be elastic beam supported on a viscoelastic foundation. Method of analysis for the beam on elastic foundation was extended to the time dependent problem and numerical method based on the finite difference method was used. As the results of numerical calculations, it was clarified that while DCB specimen bonded with epoxy adhesives containing 0 and 20 phr of flexibilizer did not show the nonlinearity on load-deflection curve, those with 40 and 60 phr of flexibilizer showed the slight nonlinearity. Strain energy release rate of the DCB specimen was calculated from the load-deflection relation by employing the least squares method. Fracture toughness was estimated with experimental data and the derived equations of strain energy release rate. Other time independent methods for estimating fracture toughness of DCB specimen were also used, and results obtained by these all estimation methods were compared with each other. In consequence, no clear distinction between two kinds of fracture toughness estimated with time dependent equation and time independent equation was observed, because the relaxation time of epoxy adhesive was relatively large

Supplementary Material for: Urinary Immunoglobulin G Is Associated with Deep and Infratentorial Cerebral Microbleeds in Stroke Patients

Background: Cerebral microbleeds (CMBs) detected on susceptibility-weighted imaging (SWI) are associated with cerebral small vessel disease. Chronic kidney disease and microalbuminuria have been associated with the presence of CMBs in stroke patients. Urinary immunoglobulin G (IgG) is measured to document glomerular injury; however, the relationship between urinary IgG and CMBs is unknown. Methods: We retrospectively enrolled consecutive patients who had been admitted with transient ischemic attack (TIA) or ischemic stroke and identified those who had undergone SWI and a spot urine test. The location of CMBs was classified on magnetic resonance imaging as strictly lobar, deep/infratentorial (D/I), or mixed areas. We analyzed the association between urinary IgG and the presence and location of CMBs. Results: We included 298 patients (86 female, median age 70 years, median eGFR 65.8 mL/min/1.73 m2). Positive urinary IgG and CMB results were found in 58 (19%) and 160 patients (54%), respectively. Urinary IgG positivity was significantly associated with CMBs compared with non-CMBs (28% vs. 9%, p p p p Conclusions: Urinary IgG was associated with the prevalence of D/I or mixed location CMBs in TIA or ischemic stroke patients. Our findings provide new insights into the association between urinary IgG and the distribution of CMBs