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A fibrillar-shaped metastable smectic phase forms during orientation-induced crystallization of poly(ethylene terephthalate). We investigated the effects of dimensions and regularity of the smectic phase on the mechanical properties by high-precision X-ray measurements. The drawing stress dependence was 76-168 MPa and the spinning speed dependence of 250-2000 m/min. The proportion, persistence length, and thickness of the smectic phase achieved their maximum values at 0.3-0.4 ms after necking. At this time g(II) also reached a minimum value of 3.7%-4.3%. The persistence length increased linearly with the natural draw ratio of as-spun fibers at less than 1500 m/min. The maximum values of the proportion, persistence length, and thickness showed no dependence on the drawing stress; however, the proportion and persistence length increased more rapidly. The increase of d-spacing with drawing stress led to an apparent elastic modulus of approximately 40 GPa for the oriented molecular bundle., Article, POLYMER.164:163-173(2019)

Fiber properties are decided by its structure, and the structure are mainly formed in the fiber drawing process. In this study, the effects of the draw ratio on the fiber structure development of polyethylene terephthalate after continuous neck-drawing were investigated using simultaneous WAXD/SAXS measurements. Low-oriented amorphous as-spun fibers were drawn to a draw ratio of 3.0-4.5, at which the fiber can be stably neck drawn. WAXD and SAXS images were obtained up to 2.0 ms when the structure was mainly developed. The smectic (0010) diffraction intensity and long period increased with increasing draw ratio up to 4.2, and a larger (0010) diffraction d-spacing was observed at a draw ratio of 4.5. The results suggest that more fibrillar structures were formed with increasing draw ratio up to 4.2, and more constrained molecular bundles were formed at a draw ratio of 4.5. A larger amount of constrained fibrillar structures can bear a greater tensile force in tensile tests, therefore the drawn fibers have higher tensile strengths. (C) 2017 Elsevier Ltd. All rights reserved., Article, POLYMER.116:357-366(2017)

The effect of draw ratio, molecular weight, and sea-island conjugated spinning with a polystyrene component on the fiber structure development of PET during laser drawing was analyzed by in-situ measurements with a 0.1ms time resolution using an ultra-high luminance X-ray beam generated from a synchrotron equipped with an undulator. The fiber temperature increased from 120°C to 160–220°C during the structure development process. By drawing the higher molecular weight PET to a higher draw ratio, a larger amount of fibrillar smectic mesophase formed just after the onset of necking, and a more highly oriented crystal formed after the extinction of the smectic mesophase. Accordingly, fibers with higher strength and higher thermal shrinkage stress were obtained. On the other hand, by conjugated spinning with a PS component, the fiber temperature increased along with an increase in the drawing stress, but the stress applied to the PET component should have decreased. The amount of smectic mesophase formed by the conjugated-spinning process was drastically decreased, and no crystallization induction time was observed, unlike the other cases. Crystallization, particularly the growth of a lamellar crystal, was also promoted. Moreover, a higher Young's modulus, a higher yield stress, and a higher shrinkage stress were observed for the conjugated-spun and drawn fibers. Therefore, the fibrillar smectic mesophase seems to block the formation of the lamellar crystal. Furthermore, the resultant fibrillar structure tends to result in a higher strength, but a relatively lower modulus and yield strength of the fiber., Article, POLYMER. 79:37-46 (2015)

This paper investigates potential space options for mitigating the impact of tropical cyclones on cities and civilians. Ground-based techniques combined with space-based remote sensing instrumentation are presented together with space-borne concepts employing space solar power technology. Two space-borne mitigation options are considered: atmospheric warming based on microwave irradiation and laser-induced cloud seeding based on laser power transfer. Finally technology roadmaps dedicated to the space-borne options are presented, including a detailed discussion on the technological viability and technology readiness level of our proposed systems. Based on these assessments, the space-borne cyclone mitigation options presented in this paper may be established in a quarter of a century.

The improvement of concentration performance was examined extensively for freeze concentration assisted with the use of shaking of the solution. Freeze concentration experiments of vitamin B1 aqueous solution were conducted using a reciprocal shaker, thereby generating the oscillatory motion, for a variety of amplitude and frequency conditions. The increase in the amplitude and frequency caused the decrease in the average distribution coefficient and the increase in the growth rate of the ice crystal, leading to the improvement of the performance of freeze concentration. The variations of solute concentration in the solution with freezing time were well described on the basis of the empirical equations representing the growth rate of ice crystal and the average distribution coefficient as functions of the shaking conditions such as the amplitude and frequency. The average distribution coefficient was maintained substantially constant throughout the course of freeze concentration, but the local distribution coefficient evaluated from the average distribution coefficient increased with the progress of freeze concentration, resulting in the reduction in the concentration efficiency. The increase in the freezing rate brought about the increase in the concentration rate in a shaking type of freeze concentration, but the excessive increase in the freezing rate is less-helpful for the improvement in the performance of freeze concentration.

Azulene derivatives reacted with N-oxide of several heterocycles in the presence of trifluoromethanesulfonic anhydride (Tf2O) to afford 1-(pyridyl, quinolyl, and isoquinolyl)azulenes in good yield, respectively. In the case of the reaction with the 1-azulenyl methyl sulfide (12), 1,1′-biazulene derivative 13 was obtained under the similar reaction conditions. The first synthesis of unsymmetrical 1,3-di(pyridyl)azulene derivative was also established via our new preparation method following the electrophilic pyridinylation using the reaction with pyridine in the presence of Tf2O.

Background & Aims Body weight (BW) loss and reduction of blood ghrelin level are commonly observed after total gastrectomy (TG). A prospective study was designed to elucidate whether exogenous ghrelin administration prevents postoperative BW loss by improving appetite and oral food intake in patients with gastric cancer after undergoing TG. Methods In this randomized phase II study, 21 patients undergoing TG were assigned to a ghrelin (11 patients) or placebo group (10 patients). They received intravenous infusion of synthetic human ghrelin (3 μg/kg) or saline twice daily for 10 days after starting oral food intake following surgery. Changes in BW, appetite visual analog scale score, food intake calories, body composition, basal metabolic rate, and various blood test results were evaluated. Results Excluding one patient who developed profound diaphoresis during ghrelin infusion, 20 patients completed the study. Food intake and appetite were significantly higher with ghrelin compared with placebo (average, 13.8 vs 10.4 kcal/kg/day [ P = .030] and 5.7 vs 3.9 cm [ P = .032], respectively). BW loss was significantly lower in the ghrelin than in the placebo group (−1.4% vs −3.7%; P = .044). Fat mass, lean body mass, and basal metabolic rate decreased significantly in the placebo group; however, the reductions in lean body mass and basal metabolic rate were not significant in the ghrelin group, although that of fat mass was significant. Conclusions Short-term administration of synthetic ghrelin was safe and successfully lessened postoperative BW loss and improved appetite and food intake after TG.

BACKGROUND: The injection of the biological adhesive fibrin glue is often performed to treat postoperative digestive fistulas. However, it is not always effective especially in case of complex fistulas with large cavities, because the fibrin glue will coagulate before the mixed solutions fill the cavity, creating dead space. We report the results of fibrin glue injection with diluted thrombin solution. METHODS: We studied the tensile strength and coagulation time of the resulting fibrin glue at each dilution of the thrombin solution. Based on in vitro study, 18 patients who had developed postoperative digestive fistula were treated by fibrin glue injection with diluted thrombin solution. RESULTS: In vitro study proved that the dilution of thrombin prolonged the coagulation time of the fibrin glue to more than 1 minute with almost no change to the tensile strength of the glue until a certain dilution was reached. The fistulas of 16 patients were successfully closed. CONCLUSIONS: Our simple method of fibrin glue injection is useful for refractory postoperative digestive fistula, even in cases of complex fistula with large cavities.

4,4′-Bis[2-(2-phenylethynyl)-3-thienyl]biphenyl, 4,4′-bis[2-{2-(trimethylsilyl)ethynyl}-3-thienyl]biphenyl and their congeners were prepared and their properties were studied. Extension of π-system through the central benzene ring was suggested by UV–vis spectra. Connection of two 1,4-bis[2-{2-(trimethylsilyl)ethynyl}-3-thienyl]benzene units was exemplified.

Vehicle trajectories for emergency obstacle avoidance are analyzed from a viewpoint of optimal control. The performance function consists of integrals of longitudinal acceleration, lateral acceleration and control effort is defined to formulate the obstacle avoidance problem as an optimal control problem. A numerical optimization method called a direct optimization is applied to calculate the optimal steering program. Using a nonlinear vehicle model, physical constraints such as saturation of control input, inequality constraints for vehicle trajectories, and equality constraints for terminal vehicle states are taken into account. The solutions to the optimal control problem provide valuable insight into the vehicle maneuver at the obstacle avoidance situations.

A nonlinear control system that integrates active four wheel steering and four wheel torque control is introduced in this paper. The theory for continuous time nonlinear predictive control is applied to the design of the control system. The advantages of coordination of four wheel steering and individual wheel torque control are demonstrated through computer simulations. Simulations in which the driver dynamics are taken into account are also carried out. The results of the simulation show that the vehicle maneuverability and stability can be remarkably improved even in a near limit cornering condition by the proposed nonlinear control system.

The small angle X-ray diffraction intensity of superlattices (SLs) has been formulated on the basis of a trapeziform composition profile. The analysis using this model enables us to estimate the interface width as well as the layer thicknesses. A GaAs/AlAs SL was characterized according to this method, and the SL period was precisely determined with consideration of the effect of refraction. The scheme presented here has been shown to be useful for studies on structural modifications of SLs with a long period as large as tens of nanometres.