84 research outputs found

    Propulsion performance optimization of “neighbour duct” by CFD

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    As one of measures against CO2 reduction regulation by EEDI, energy-saving device (ESD) has been widely used. As one of ESD, the authors developed "Neighbour Duct" which was a vertical-long-oval stern duct. Neighbour Duct generates thrust by harnessing flow along both sides of stern. By CFD, the geometric parameter of Neighbour Duct was optimized, and the principle of thrust generation was made clear. In order to verify the result of CFD, a series of model test was carried out at National Maritime Research Institute (NMRI), the thrust deduction factors of both CFD and model test results were good agreement. As Estimation of performance of actual ship based on the model test, BHP was reduced 4.4% by Neighbour Duct. In addition, 1-w only decreased by 1%. Therefore it was found that CO2 reduction effect would be obtained by Neibour Duct without changing the propeller or propeller design

    The development of “Ultimate Rudder” for EEDI

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    EEDI (Energy Efficiency Design Index) came into effect mandatory in Jan. 2013, and the ship owners definitely required a higher efficiency propulsion system than ever before. Hence, the shipyards have been conducting an optimization of ESD (Energy Saving Device) system in self-propulsion test for each project. As the results, the shipyards have installed a rudder bulb as an effective ESD. The rudder bulb is a popular ESD system from a long time ago. Mewis1) described that the rudder bulb was developed by Costa in 1952 and the efficiency improve by the rudder bulb for a container vessel was 1% on average. Fujii et al.2) developed “MIPB (Mitsui Integrated Propeller Boss)” as an advanced rudder bulb. The feature of MIPB was a streamlined profile from propeller cap to rudder. According to their paper, the efficiency improve by installing MIPB was 2-4%. Recently, NAKASHIMA PROPELLER Co., Ltd. developed ECO-Cap (economical propeller cap)3) as a new ESD with FRP (Fiber Reinforced Plastics). The strength of FRP is higher than that of NAB (Nickel Aluminium Bronze), therefore ECO-Cap was able to adopt thin fins on propeller caps for low resistance. Although the material used for the energy- saving propeller cap was generally NAB, the research results on FRP showed that FRP could be used as ESD due to their properties such as lightweight and flexibility. As explained above, the authors thought that there was a possibility to evolve the rudder bulb profile using the easily moldable FRP compared with NAB. This paper described about the development of “Ultimate Rudder” of new design concept by FRP. The authors optimized the profile of “Ultimate Rudder” by CFD and confirmed the efficiency increase from 4.9 to 5.4% in self-propulsion test

    Radiation therapy for oligometastatic bone disease in breast cancer

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    Breast cancer (BCa) frequently metastasizes to the bone. BCa patients with oligometastatic bone diseases have much more favorable outcomes than those with metastatic bone disease. Radiation therapy (RT), especially stereotactic body radiation therapy (SBRT), is advised for the treatment of patients with oligometastatic bone disease in other primary sites. "This line of treatment provided favorable outcomes in patients and resulted in only mild toxicities. A similar strategy has been suggested for treatment of BCa patients with oligometastatic bone disease. BCa, bone-only, or high radiation dose are reported to have been associated with good outcomes in RT for metastatic disease. Furthermore, based on the guidelines provided by the BCa expert panel of the German Society for Radiation Oncology and members of the Working Party of Gynecologic Oncology Breast Committee and in line of the results obtained in other primary sites, our group supports the use of high-dose RT or SBRT for the treatment of BCa patients with oligometastatic bone disease. Additionally, the use of magnetic resonance imaging (MRI) for proper target volume definition and three-dimensional (3D) treatment planning especially for lesions of the trunk are essential for the treatment planning of RT. Of note, several clinical trials have combined RT with immune checkpoint inhibitors for the treatment of BCa patients with metastatic disease. Based on this, we anticipate that combined RT and ICI may serve as a better treatment modality for BCa patients with oligometastatic bone disease

    Study on the rudder characteristics of ultimate rudder by numerical calculation

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    The authors invented Ultimate Rudder3) as the rudder with bulb. The authors calculated the rudder characteristics of the normal rudder and Ultimate Rudder by CFD at several steering angles and compared these values. The result showed that regardless of the presence or absence of the bulb, signs of separation appear on the control surface with a steering angle of 20 deg. to 30 deg. and regarding the steering torque coefficient, it was found that the steering torque coefficient of Ultimate Rudder is larger than the normal Rudder when the steering angle is less than 20 deg. and also the steering torque coefficient can be decreased by changing the shape of the rudder bulb

    Radiation pneumonitis after definitive concurrent chemoradiotherapy with cisplatin/docetaxel for non-small cell lung cancer: Analysis of dose-volume parameters

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    Background: Radiation pneumonitis (RP) is a major pulmonary adverse event of chest radiotherapy. The PACIFIC trial that identified durvalumab as an effective subsequent-line therapy after concurrent chemoradiotherapy (CCRT) found that patients with grade 2 or higher RP may have to be excluded from treatment under certain criteria. The purpose of this study was to investigate the relationship between grade ≥2 RP and the parameters of dose-volume histograms after CCRT with cisplatin/docetaxel for stage III non-small cell lung cancer and conduct a subset analysis of severe RP that can lead to the permanent discontinuation of treatment per the PACIFIC trial criteria to help determine treatment strategy. Methods: We calculated the percentage of the lung volume received at least 5 Gy (V5) and 20 Gy (V20), the mean lung dose (MLD), and the lung volume spared from a 5 Gy dose (VS5) to the total lung volume. Factors affecting the incidence of grade ≥2 RP were identified; severe RP was defined as grade ≥3 as well as grade 2 RP that required ≥10 mg prednisolone for at least 12 weeks. Results: This study included 45 patients. On univariate analysis, all parameters and total lung volume were found to be significant predictors of grade ≥2 RP (P = .001, .003, .03, .004, and .02, respectively). On multivariate analysis, V20 was a significant predictive factor of grade ≥2 RP (P = .007). Severe RP developed in 6 of 37 patients (16.2%) whose V20 values were 35% or lower. On univariate analysis, only V20 was a significant predictor of severe RP in these patients (P = .01). Conclusions: The best approach to reduce the rate of grade ≥2 RP is to maintain the V5, V20, MLD, and VS5 as low as possible during radiotherapy planning in patients receiving definitive CCRT with cisplatin/docetaxel

    Cardiolipin supports respiratory enzymes in plants in different ways

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    In eukaryotes the presence of the dimeric phospholipid cardiolipin (CL) is limited to the mitochondrial membranes. It resides predominantly in the inner membrane where it interacts with components of the mitochondrial electron transfer chain. CL deficiency has previously been shown to affect abundances of the plant NADHdehydrogenase complex and its association with dimeric cyctochrome c reductase. Using an Arabidopsis thaliana knock-out mutant for the final enzyme of CL biosynthesis we here extend current knowledge on the dependence of plant respiration on CL. By correlating respiratory enzyme abundances with enzymatic capacities in mitochondria isolated from wild type, CL deficient and CL complemented heterotrophic cell culture lines a new picture of the participation of CL in plant respiration is emerging. Data indicate a loss of a general reduction of respiratory capacity in CL deficient mitochondria which cannot solely be attributed to decreased abundances or capacities of mitochondrial electron transfer protein complexes and supercomplexes. Instead, it most likely is the result of a loss of the mobile electron carrier cytochrome c. Furthermore, enzymes of the tricarboxylic acid cycle are found to have lower maximum activities in the mutant, including the succinate dehydrogenase complex. Interestingly, abundance of the latter is not altered, indicative of a direct impact of CL deficiency on the enzymatic capacity of this electron transfer chain protein complex

    New field‑in‑field with two reference points method for whole breast radiotherapy: Dosimetric analysis and radiation‑induced skin toxicities assessment

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    The usefulness of the field‑in‑field with two reference points (FIF w/ 2RP) method, in which the dose reference points are set simultaneously at two positions in the irradiation field and the high‑dose range is completely eliminated, was examined in the present study with the aim of decreasing acute skin toxicity in adjuvant breast radiotherapy (RT). A total of 573 patients with breast cancer who underwent postoperative whole breast RT were classified into 178 cases with wedge (W) method, 142 cases with field‑in‑field without 2 reference points (FIF w/o 2RP) method and 253 cases with FIF w/ 2RP method. Using the FIF w/ 2RP method, the high‑dose range was the lowest among the three irradiation methods. The planning target volume (PTV) V105% and the breast PTV for evaluation (BPe) V105% decreased to 0.09 and 0.10%, respectively. The FIF w/ 2RP method vs. the FIF w/o 2RP method had a strong association (η) with PTV V105% (η=0.79; P<0.001) and BPe V105% (η=0.76; P<0.001). The FIF w/ 2RP method had a significant impact on lowering the skin toxicity grade in weeks 3 and 4, and increasing the occurrence of skin toxicity grade 0. The FIF w/ 2RP method vs. the W method had a moderate association with skin toxicity grade at week 3 (η=0.49; P<0.001). Using the FIF w/ 2RP method, the high‑dose range V105% of the target decreased to 0%, and skin adverse events were decreased in conjunction. For patients with early‑stage breast cancer, particularly patients with relatively small‑sized breasts, the FIF w/ 2RP method may be an optimal irradiation method

    Dose-volume parameters predict radiation pneumonitis after induction chemoradiotherapy followed by surgery for non-small cell lung cancer: a retrospective analysis

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    BACKGROUND: The relationship between lung dose-volume histogram (DVH) parameters and radiation pneumonitis (RP) associated with induction concurrent chemoradiotherapy (CCRT) followed by surgery in patients with non-small cell lung cancer (NSCLC) is unclear, particularly when concerning irradiation of the whole lung prior to resection. We performed this study to identify factors associated with grade ≥ 2 RP in such patients. METHODS: Patients who received induction CCRT (chemotherapy: cisplatin and docetaxel; radiotherapy: 46 Gy/23 fractions) between May 2003 and May 2017 were reviewed. The mean lung dose (MLD) and the percentage of the lung volume that received ≥5 Gy (V5) and ≥ 20 Gy (V20) were calculated. Factors associated with the development of grade ≥ 2 RP were analyzed. RESULTS: One hundred and eight patients were included in this study, 34 (31.5%) of whom experienced grade ≥ 2 RP. A V20 ≥ 21%, an MLD ≥10 Gy, and a lower lobe tumor location were significant predictors of grade ≥ 2 RP on univariate analysis (p = 0.007, 0.002, and 0.004, respectively). Moreover, an MLD ≥10 Gy and lower lobe location were significant predictors of grade ≥ 2 RP on multivariate analysis (p = 0.026 and 0.0043, respectively). The cumulative incidence rates of grade ≥ 2 RP at 6 months were 15.7 and 45.6% in patients with MLDs CONCLUSIONS: MLD and lower lobe location were predictors of grade ≥ 2 RP in patients who received induction CCRT. It is necessary to reduce the MLD to the greatest extent possible to prevent the occurrence of this adverse event
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