Performance of non-destructive evaluation by diffracted SH ultrasonic waves in predicting degree of fatigue in cyclic bending of ferritic steel

The degree of fatigue in ferritic wrought steel during cyclic bending was determined by analysis of diffracted SH ultrasonic waves with the aid of multiple regression analysis. As the degree of fatigue increases, accompanied by residual stress, the incident waves curve to the interior region with positive stress field owing to the acoustoelastic effect. As a result, the propagation time of the launched waves lengthens, leading to a modulation of the received waveform. Multiple regression analysis for the waveform modulation produces a reliable estimation, with correlation coefficient of 0.948, for the degree of fatigue.     

On phenomenological failure criteria for composite bolted joint analysis

There has been a recent trend to use phenomenological strength models in combination with point stress or average stress failure criteria to form strength models for the analysis of composite bolted joints. Several papers published using these approaches have demonstrated practical reductions in the size of the empirical data base required to perform bolted joint analysis for specific materials and laminates. Since the inception of phenomenological failure models for bolted joints several refinements have been proposed, but the generality of the method is not clearly defined. This paper addresses the concepts underlying the formulation of these strength models, compares the capabilities of several commonly used failure criteria and discusses the limits of applicability through example analyses and comparison with experimental data. The results indicate that differences in predicted strengths for the models examined were insignificant. Failure mode predictions based on single point failure location information varied from model to model and differed significantly from experimentally observed failure modes for some geometries. The models cannot be applied with confidence for the analysis of a wide class of laminates and geometries without calibrating the model through empirical data.     

Orientation of nanowires consisting of poly(3-hexylthiophene) using strong magnetic field

Nanowires consisting of regioregular poly(3-hexylthiophene) (P3HT) as a conducting polymer were prepared using p-xylene. Magnetic processing of the nanowires was carried out using two superconducting magnets with horizontal (B_max = 8 T) and vertical (B_max = 10 T) directions. The formation of the nanowires was confirmed by atomic force microscopy (AFM) measurement. The results from the AFM images and the polarized absorption spectra on glass plates indicated that the nanowires partly oriented themselves with their long axes, which are parallel to the π–π stacking direction, being perpendicular to the magnetic field. The magnetic orientation is most likely ascribed to anisotropy in the magnetic susceptibilities of the ordered P3HT in the nanowires.     

Morphology development and exclusion of noncrystalline polymer during crystallization in PVDF/PMMA blends

Morphology development during the crystallization of poly(vinylidene fluoride) (PVDF)/poly(methyl methacrylate) (PMMA) blends was investigated at various crystallization temperatures (T_C) by means of time-resolved light scattering measurements and atomic force microscopy (AFM). A coarse spherulite obtained at a high T_C of 162 °C was found to be developed with a two-step crystallization process. The ordering in the spherulites (Pr) increased with time at the early stages and then decreased at the later stages. The rate of spherulite growth started to decrease when Pr started to decrease. In contrast, in the compact spherulite obtained at a low T_C of 148 °C, Pr decreased monotonously with time while the growth rate was constant. AFM observation revealed that such characteristic crystallization behavior is attributed to the exclusion of PMMA from the crystal growth during the crystallization; i.e., the amount of excluded PMMA becomes larger as the distance from the spherulite center increases and the crystallization temperature rises.     

Preparation and evaluation of a novel wound dressing sheet comprised of β-glucan–chitosan complex

A transparent wound dressing sheet was obtained by forming a complex between β-glucan and chitosan (CS). These materials were chosen for their biocompatible, bioabsorbable, and biodegradable properties, and they were expected to promote the therapeutic efficacy of the dressing by increasing the wound healing response. The therapeutic efficacy of the β-glucan–CS complex sheet as a wound dressing was evaluated in wounds created on the dorsal surfaces of mice. β-glucan–CS complex sheets demonstrated therapeutic efficacies comparable or superior to that of Beschitin®W, a commercial wound dressing made from CS. Additionally, the β-glucan–CS complex sheet did not dissolve during the application period, did not adhere to wounds, and was easy to remove. Cumulatively, these results indicate that β-glucan–CS complex sheets are a promising new wound dressing product.     

Novel transdermal drug delivery system with polyhydroxyalkanoate and starburst polyamidoamine dendrimer

In search of an efficient transdermal drug delivery system (TDDS), a polyhydroxyalkanoate (PHA)-based system with a polyamidoamine dendrimer was examined. Tamsulosin was used as the model drug. The dendrimer was found to act as the weak enhancer. By adding the dendrimer, the dendrimer-containing PHA matrix achieved the clinically required amount of tamsulosin permeating through the skin model. This is also the first report of the application of PHA and dendrimer to the TDDS.     

Effect of Powder Injection on the Interfacial Fracture Toughness of Plasma-Sprayed Zirconia

Adhesive strength of the plasma-sprayed thermal barrier coating is one of the most important parameters which influence their durability and reliability during service. While many methods exist to measure the adhesive strength, in general, they require cumbersome and time-consuming specimen preparation. Furthermore, considerations of the adhesion strength from the point-of-view of fracture toughness or for that matter, their systematic correlation to both processing variances are limited. Consequently, there is an opportunity to both simplify the measurement procedure and establish correlations among methods and linkages between processing parameters and interfacial fracture toughness. In this paper, we report results on adhesion strength of plasma-sprayed yttria-stabilized zirconia (YSZ) coating on aluminum substrates based on both interfacial indentation test (to measure interfacial fracture toughness) and the modified tensile adhesive test. Carrier gas flow for powder injection into the plasma torch was systematically varied to introduce variances in particle melting with concomitant impact on the measured adhesive strength. The results indicate the correlation between the particle melting index and the measured interfacial fracture toughness.     

Abdominal incisional hernia occurring after an esophagectomy reconstructed with a gastric tube through an antesternal route: report of a case

A Japanese man, who had undergone a subtotal esophagectomy reconstructed with a gastric tube through an antesternal route for esophageal carcinoma 16 years previously, was admitted to our hospital because of an abdominal incisional hernia. The abdominal incisional hernia was in his upper abdomen and was difficult to push back into the intraabdominal cavity by hand. The hernia was successfully repaired by operation. We thus conclude that an abdominal incisional hernia is a rare but important late-phase complication occurring after an esophagectomy reconstructed with either an antesternal or retrosternal route, and an operation should be the treatment of choice.     

Interstitial pneumonia treated with intermittent cyclophosphamide pulse therapy

A 52-year-old woman was admitted to the hospital because of polyarthralgia and dry coughing. A chest X-ray film showed bilateral diffuse reticulo-nodular shadows. A specimen obtained by transbronchial lung biopsy revealed alveolar septal thickening and infiltration by mononuclear cells. Interstitial pneumonia associated with rheumatoid arthritis was diagnosed. Interstitial pneumonia relapsed soon after the first pulse of corticosteroid therapy. Cyclophosphamide pulse therapy was given in addition to a second pulse of corticosteroid therapy; 700 mg of cyclophosphamide (500 mg/m2) was administered intravenously every month and the dose of steroids was gradually reduced. Cyclophosphamide pulse therapy was repeated three times and the dose of oral corticosteroids was reduced from 60 mg to 35 mg. There was no bone marrow suppression or hemorrhagic cystitis after the cyclophosphamide pulses. Eventually, corticosteroid therapy was stopped with no clinical deterioration. This case suggests that intermittent cyclophosphamide pulse therapy can be effective for treatment of interstitial pneumonia unresponsive to corticosteroids.