In this paper, suppression effect of a gyroscopic damper on vibrations of a body levitated by magnetic force acting from superconductors is investigated by numerical calculations. Because of the low ...damping property of the superconducting magnetic levitation system, simultaneous suppression of multi-degree-of-freedom vibration due to the coupled translational and tilting motions of the levitating body and suppression of nonlinear vibration are important development issues. A gyroscopic damper has been considered as a passive vibration suppression method that takes advantage of the control-free features of superconducting magnetic levitation systems, and if the design parameters are optimized, it may be possible to simultaneously suppress not only tilt vibration but also translational vibration. In this paper, the governing equations are first derived from the analytical model, and then numerical calculations are performed. As a result, the simultaneous suppression effect of the gyroscopic damper on the translational and tilt vibrations of the levitating body was numerically confirmed. Furthermore, the suppression effect of the gyroscopic damper on the nonlinear vibration of the levitating body was also confirmed numerically.
The effects of climate change on the taste and textural attributes of foods remain largely unknown, despite much public interest. On the basis of 30-40 years of records, we provide evidence that the ...taste and textural attributes of apples have changed as a result of recent global warming. Decreases in both acid concentration, fruit firmness and watercore development were observed regardless of the maturity index used for harvest date (e.g., calendar date, number of days after full bloom, peel colour and starch concentration), whereas in some cases the soluble-solids concentration increased; all such changes may have resulted from earlier blooming and higher temperatures during the maturation period. These results suggest that the qualities of apples in the market are undergoing long-term changes.
This paper presents experimental verification of the vibration suppression effect of a gyroscopic damper on a system supported elastically by a superconducting magnetic levitation system when ...subjected to vibration. While superconducting magnetic levitation systems are capable of uncontrolled and stable levitation, they are prone to multi-degree-of-freedom vibration and nonlinear vibration of the levitating body due to their low damping. In our previous study, we have numerically predicted that a gyroscopic damper, a passive vibration control method, may be effective in simultaneously suppressing translational and tilting vibrations by optimizing the design parameters. In this paper, this vibration suppression effect predicted was investigated through experiments. In the experiment, nonlinear vibration of the levitating body occurred, which may have been caused by the magnetic force of the superconductivity, but the motion coupling of the gyroscopic damper and the levitating body was found to reduce that vibration by 30% in the translational direction and by 40% in the tilting direction. The gyroscopic damper was thus demonstrated to be effective in simultaneously suppressing the translational and tilting vibration of the levitating body.
Recent climate change has resulted in warmer temperatures. Warmer temperatures from autumn to spring has negatively affected dormancy progression, cold (de)acclimation, and cold tolerance in various ...temperate fruit trees. In Japan, a physiological disorder known as flowering disorder, which is an erratic flowering and bud break disorder, has recently emerged as a serious problem in the production of the pome fruit tree, Japanese (Asian) pear (
Nakai). Due to global warming, the annual temperature in Japan has risen markedly since the 1990s. Surveys of flowering disorder in field-grown and greenhouse-grown Japanese pear trees over several years have indicated that flowering disorder occurs in warmer years and cultivation conditions, and the risk of flowering disorder occurrence is higher at lower latitudes than at higher latitudes. Susceptibility to flowering disorder is linked to changes in the transcript levels of putative dormancy/flowering regulators such as
(
) and
(
). On the basis of published studies, we conclude that autumn-winter warm temperatures cause flowering disorder through affecting cold acclimation, dormancy progression, and floral bud maturation. Additionally, warm conditions also decrease carbohydrate accumulation in shoots, leading to reduced tree vigor. We propose that all these physiological and metabolic changes due to the lack of chilling during the dormancy phase interact to cause flowering disorder in the spring. We also propose that the process of chilling exposure rather than the total amount of chilling may be important for the precise control of dormancy progression and robust blooming, which in turn suggests the necessity of re-evaluation of the characteristics of cultivar-dependent chilling requirement trait. A full understanding of the molecular and metabolic regulatory mechanisms of both dormancy completion (floral bud maturation) and dormancy break (release from the repression of bud break) will help to clarify the physiological basis of dormancy-related physiological disorder and also provide useful strategies to mitigate or overcome it under global warming.
In this paper, we propose a new type of electromagnetic shunt damper where an air core coil is set above a floating magnet in a superconducting levitation system. The coil is connected to a shunt ...circuit consisting of a capacitance and a resistance. We have derived the optimal parameter values of capacitance C and resistance R from the fixed point theory after linearizing the governing equations and experimentally confirmed the effectiveness of the damper. We have also confirmed the electromagnetic coupling coefficient, which couples the mechanical system and the electric system and can be treated as a constant; as it is enhanced by the presence of the superconductor. Further, we have oscillated the superconductor and observed the amplitude of the floating magnet with and without the shunt damper. By the result, we have confirmed effective amplitude reduction by the shunt damper.
The future impacts of climate change on the yields of staple crops have been widely investigated. However, owing to insufficient data compared to that available for staple crops and the complexity of ...the quality determination process, the relationship between quality changes in horticultural crops and climate change has not been quantified, and potential future changes in fruit quality are not well understood. We conducted temperature treatment experiments to quantify the sensitivity of apple quality to air temperature and collected quality indices records through field observations to propose a model for estimating apple quality indices from the air temperature. In the temperature treatment experiment, ‘Fuji’ apple trees were placed in glass chambers set at a constant temperature of 17.3–25.6°C from 110 days after full bloom (DAFB). The fruits were harvested at 170 DAFB to measure the quality indices. The results indicated that the acidity and ratings for blush, peel ground color, starch disappearance, and watercore were all significantly lower at higher air temperatures. The relationship between these quality indices and air temperature could be linearly approximated. Sugar content and fruit firmness were not clearly affected by the air temperature. In addition, data from field observations conducted at experimental orchards in Aomori and Nagano Prefecture over 50 years (1970–2019) were analyzed. The relationship between fruit quality indices at 170 DAFB and the mean temperature in the 60 days from 110 DAFB in Aomori and Nagano was similar to that observed for the chamber experiment results, and no significant difference was observed in the slope of the linear regression equation between the chambers and orchards. A model was developed to estimate the fruit quality indices based on air temperature by accumulating daily amounts of change in quality indices calculated from daily mean temperatures using the results of experimental and field observations. The model could be used to assess the impact of future long-term temperature increases on apple quality indices.
A 51-year-old Thai woman diagnosed with β-thalassemia underwent regular blood transfusion and iron-chelating therapy. However, after voluntarily discontinuing treatment, the patient developed ...progressive dyspnea and was diagnosed with pulmonary hypertension following right heart catheterization. Despite resuming blood transfusions, her condition did not improve. Because the patient had a history of multiple organ failure, curative treatment for β-thalassemia was not feasible, and macitentan was administered. Despite experiencing hypotension as an adverse event, her condition remained stable during macitentan treatment. Thus, macitentan may be well tolerated in patients with pulmonary hypertension caused by β-thalassemia with multiple organ dysfunction.
This study investigated the effect of electromagnetic shunt dampers on the resonance amplitude reduction in a superconducting magnetic levitation system. There are two types of electromagnetic shunt ...dampers, series type and parallel type, depending on the configuration of the electric circuit, and their damping characteristics may differ depending on the external resistance value in the circuit. In this study, after discussing the vibration-suppression effects of both types according to the governing equations, vibration experiments were conducted using both dampers with different resistance values. As a result, it was confirmed that, for the larger resistance value, the amplitude reduction effect is smaller in the series-type damper, while it remained high in the parallel type. We also performed numerical integrations, including the nonlinearity of magnetic force in the superconducting magnetic levitation system. As a result, it was numerically confirmed that the parallel-type damper can also be expected to reduce amplitude at a resonance caused by nonlinearity.
Background:Several new treatments for chronic thromboembolic pulmonary hypertension (CTEPH) have appeared in recent years, which have led to changes in the treatment algorithm. Changes in survival ...rates and prognostic factors, however, have not been estimated so far.Methods and Results:Two hundred and eighty patients were diagnosed with CTEPH at Chiba University Hospital between June 1986 and June 2016. Survival rate was investigated by date of treatment initiation (group 1, 1986–1998; group 2, 1999–2008; group 3, 2009–2016). Survival rates were also evaluated by treatment strategy: balloon pulmonary angioplasty (BPA), pulmonary endarterectomy (PEA), and medical treatment. Group 3 had significantly better disease-specific survival than groups 1 and 2 (5-year survival: 91.9% vs. 67.1%, 77.0%, respectively). For the non-PEA (BPA+medication) strategy, group 3 had better disease-specific survival than groups 1 and 2 (5-year survival: 94.9% vs. 54.6%, 74.2%, respectively). The PEA strategy had significantly better survival than the medication strategy in groups 1 and 2, whereas no difference was observed between the BPA, PEA, and medication strategies in group 3.Conclusions:Survival in CTEPH in the recent era has significantly improved, especially in non-PEA patients. BPA and selective pulmonary vasodilators could improve survival in the non-PEA group. In the present study, no difference in survival was found between PEA and non-PEA.
PDF
