Mitigation of coupled wind-wave-earthquake responses of a 10 MW fixed-bottom offshore wind turbine

© 2020 Elsevier Ltd In this paper we present a study on the mitigation of dynamic responses of a 10 MW monopile offshore wind turbine under coupled wind-wave-earthquake excitations. We have developed and validated the generic seismic coupled analysis and structural control architecture tool to overcome the limitation of numerical tools when examining the wind-wave-earthquake coupling effects. We investigated the dynamic responses of a 10 MW monopile offshore wind turbine under different loading combinations and found that the earthquake loading increases the tower-top displacement and pile-cap moment by 47.6% and 95.1%, respectively, compared to the wind-wave-only condition. It is found that the earthquake-induced vibration in the fore-aft direction is mitigated by the wind and wave loadings due to the energy dissipated by the aerodynamic and hydrodynamic damping. In addition, the tower responses are dominated by the earthquake excitation. In order to alleviate the tower vibration induced by the earthquake, we implemented the structural control capability within the tool using tuned mass dampers. The tuned mass dampers with appropriately selected design parameters achieve a larger mitigation on the tower-top displacement for the earthquake-only condition compared to the coupled-loading scenario. The reason is that the tuned mass damper is only effective in mitigating tower vibration, and it is not capable of reducing the tower elastic deformation which is the major contribution of the tower displacement for the coupled-loading condition. In addition, we have found that a heavier tuned mass damper requires a lower tuned frequency to achieve a larger mitigation. A configuration for the mitigation control of the 10 MW offshore wind turbine is suggested by using a 5% mass ratio of the tuned mass damper

Wind-Wave Coupling Effects on the Fatigue Damage of Tendons for a 10 MW Multi-Body Floating Wind Turbine

This study investigates the wind-wave coupling effects on fatigue damage of tendons that connect multiple bodies of a novel floating platform (TELWIND) supporting a 10 MW wind turbine. An aero-hydro-servo tool is developed for dynamic analysis of a multi-body floating wind turbine (FWT) platform, by incorporating AeroDyn with AQWA through a user-defined dynamic library link (DLL) to conduct simulations of the FWT subjected to wind, wave and current loadings. The comparison against FAST has validated the accuracy of the AQWA-AeroDyn coupling framework in predicting coupled responses of the FWT. A specific site in the northern coast of Scotland is selected and design load cases are examined for the estimation of the fatigue damage of the tendons of the FWT. In the absence of wind-wave coupling, the motion differences between the two bodies of the platform are larger, leading to 43.7% enhancement in the tension fluctuation of tendons in average. Consequently, the fatigue damage of the tendons is significantly overestimated. Also, the investigation on the influence of effective simulation length on the fatigue damage shows that 90% accuracy can be achieved when 20% of the simulation analysis length is decreased

deFuse: An Algorithm for Gene Fusion Discovery in Tumor RNA-Seq Data

Gene fusions created by somatic genomic rearrangements are known to play an important role in the onset and development of some cancers, such as lymphomas and sarcomas. RNA-Seq (whole transcriptome shotgun sequencing) is proving to be a useful tool for the discovery of novel gene fusions in cancer transcriptomes. However, algorithmic methods for the discovery of gene fusions using RNA-Seq data remain underdeveloped. We have developed deFuse, a novel computational method for fusion discovery in tumor RNA-Seq data. Unlike existing methods that use only unique best-hit alignments and consider only fusion boundaries at the ends of known exons, deFuse considers all alignments and all possible locations for fusion boundaries. As a result, deFuse is able to identify fusion sequences with demonstrably better sensitivity than previous approaches. To increase the specificity of our approach, we curated a list of 60 true positive and 61 true negative fusion sequences (as confirmed by RT-PCR), and have trained an adaboost classifier on 11 novel features of the sequence data. The resulting classifier has an estimated value of 0.91 for the area under the ROC curve. We have used deFuse to discover gene fusions in 40 ovarian tumor samples, one ovarian cancer cell line, and three sarcoma samples. We report herein the first gene fusions discovered in ovarian cancer. We conclude that gene fusions are not infrequent events in ovarian cancer and that these events have the potential to substantially alter the expression patterns of the genes involved; gene fusions should therefore be considered in efforts to comprehensively characterize the mutational profiles of ovarian cancer transcriptomes

Sporangiospore Size Dimorphism Is Linked to Virulence of Mucor circinelloides

Mucor circinelloides is a zygomycete fungus and an emerging opportunistic pathogen in immunocompromised patients, especially transplant recipients and in some cases otherwise healthy individuals. We have discovered a novel example of size dimorphism linked to virulence. M. circinelloides is a heterothallic fungus: (+) sex allele encodes SexP and (−) sex allele SexM, both of which are HMG domain protein sex determinants. M. circinelloides f. lusitanicus (Mcl) (−) mating type isolates produce larger asexual sporangiospores that are more virulent in the wax moth host compared to (+) isolates that produce smaller less virulent sporangiospores. The larger sporangiospores germinate inside and lyse macrophages, whereas the smaller sporangiospores do not. sexMΔ mutants are sterile and still produce larger virulent sporangiospores, suggesting that either the sex locus is not involved in virulence/spore size or the sexP allele plays an inhibitory role. Phylogenetic analysis supports that at least three extant subspecies populate the M. circinelloides complex in nature: Mcl, M. circinelloides f. griseocyanus, and M. circinelloides f. circinelloides (Mcc). Mcc was found to be more prevalent among clinical Mucor isolates, and more virulent than Mcl in a diabetic murine model in contrast to the wax moth host. The M. circinelloides sex locus encodes an HMG domain protein (SexP for plus and SexM for minus mating types) flanked by genes encoding triose phosphate transporter (TPT) and RNA helicase homologs. The borders of the sex locus between the three subspecies differ: the Mcg sex locus includes the promoters of both the TPT and the RNA helicase genes, whereas the Mcl and Mcc sex locus includes only the TPT gene promoter. Mating between subspecies was restricted compared to mating within subspecies. These findings demonstrate that spore size dimorphism is linked to virulence of M. circinelloides species and that plasticity of the sex locus and adaptations in pathogenicity have occurred during speciation of the M. circinelloides complex

Opening Aeolus' Bag of Winds: Acute Abdominal Pain in a Severely Immunosuppressed Patient

Background Necrotizing enterocolitis (NE) is a necrotizing disease mostly of the ileocecal region. It is a severe and potentially life-threatening complication that can affect patients undergoing chemotherapy for lymphoma. We analyze a case of NE that occurred in a patient with non-Hodgkin's lymphoma during chemotherapy with concurrent HIV infection. Case Report We present a case of a 37-year-old woman who was admitted to our emergency department because of acute abdominal pain. Her medical history included HIV infection and B-cell immunoblastic lymphoma. For the latter, the patient was receiving rituximab cyclophosphamide hydroxydaunorubicin oncovin vincristine prednisone (R-CHOP) regimen. A complete blood count showed a low leukocyte count (40/mm³) and a low neutrophil count (32/mm³). An exploratory laparotomy with midline incision was performed. Intraoperatively, the cecum and the proximal part of the ascending colon were found to be edematous with the mesocolon being extremely gelatinous without macroscopically identified ischemia. Histopathology revealed a nonspecific infarction necrosis of the bowel wall with multiple ulcerations in the cecum, but no evidence of major vessel thrombosis. The patient had an uneventful postoperative course and was discharged in good condition on the 10th postoperative day. Why Should an Emergency Physician Be Aware of This? To our knowledge, this is the first reported case of NE in a patient with acquired immune-deficiency syndrome who developed the syndrome during an episode of severe neutropenia and was treated surgically. The decision to operate should be balanced between the clinical and laboratory status as well as the operative risk. Physicians should be aware of this complication of chemotherapy, especially in severely immunosuppressed patients, because it could be triggered just by an episode of neutropenia. © 2016 Elsevier Inc

Distribution and incidence of atoxigenic Aspergillus flavus VCG in tree crop orchards in California: a strategy for identifying potential antagonists, the example of almonds

Published online: 21 Oct 2017To identify predominant isolates for potential use as biocontrol agents, Aspergillus flavus isolates collected from soils of almond, pistachio and fig orchard in the Central Valley of California were tested for their membership to 16 atoxigenic vegetative compatibility groups (VCGs), including YV36, the VCG to which AF36, an atoxigenic isolate commercialized in the United States as biopesticide, belongs. A surprisingly large proportion of isolates belonged to YV36 (13.3%, 7.2% and 6.6% of the total almond, pistachio and fig populations, respectively), while the percentage of isolates belonging to the other 15 VCGs ranged from 0% to 2.3%. In order to gain a better insight into the structure and diversity of atoxigenic A. flavus populations and to further identify predominant isolates, seventeen SSR markers were then used to genetically characterize AF36, the 15 type-isolates of the VCGs and 342 atoxigenic isolates of the almond population. There was considerable genetic diversity among isolates with a lack of differentiation among micro-geographical regions or years. Since isolates sharing identical SSR profiles from distinct orchards were rare, we separated them into groups of at least 3 closely-related isolates from distinct orchards that shared identical alleles for at least 15 out of the 17 loci. This led to the identification of 15 groups comprising up to 24 closely-related isolates. The group which contained the largest number of isolates were members of YV36 while five groups were also found to be members of our studied atoxigenic VCGs. These results suggest that these 15 groups, and AF36 in particular, are well adapted to various environmental conditions in California and to tree crops and, as such, are good candidates for use as biocontrol agents

Evaluation of the use of sulfur dioxide to reduce postharvest losses on dark and green figs

Postharvest diseases limit the storage period and market life of fresh figs (Ficus carica L.). The objective of this work was to determine the effect of sulfur dioxide (SO(2)) applied by fumigation and/or by dual release SO(2) generating pads on postharvest decay and quality retention of 'Black Mission' and 'Brown Turkey' (dark skin), and 'Kadota' and 'Sierra' (green skin) figs. A protocol for the computer-controlled application of gaseous SO(2) has been developed which allows the application of very low specific concentration x time products of SO(2) and simultaneous monitoring of the application progress. In vitro tests with important fungal, yeast and bacterial postharvest pathogens plated on Petri dishes and exposed to a SO(2) concentration x time product (C x t) of 100 (mu L/L) h at different temperatures showed fewer survived at 20 degrees C than at 0 degrees C. Therefore, fumigations were carried out at 20 degrees C in the rest of the experiments. The evaluation of different SO(2) concentration x time products showed that a product of 25 (mu L/L) h provided the best compromise between decay control and fruit injury. The performance of SO(2) fumigations on warm or cold fruit, its combination with SO(2) generating pads, and the use of repeated fumigations during cold storage were also evaluated. All the SO(2) treatments tested reduced the percentage of decay, extending the market life of fresh figs. However, in some cases, the use of SO(2) generating pads increased the incidence of skin bleaching. Fumigation of warm fruit at 25 (mu L/L) h of SO(2) reduced populations of Alternaria and Rhizopus spp. growing on the fig surface. The treatment was more effective against Rhizopus spp. than against Alternaria spp. Contamination of fruit by Botrytis spp. and Penicillium spp. was also reduced by SO(2). In conclusion, results showed that SO(2) can be a potential tool to control postharvest rots and therefore increase the market life of fresh figs. (C) 2010 Elsevier B.V. All rights reserved

Structural health monitoring of tendons in a multibody floating offshore wind turbine under varying environmental and operating conditions

The structural health monitoring of a Floating Offshore Wind Turbine (FOWT) tendons, taking into account the comprehensive damage diagnosis problem of damage detection, damaged tendon identification and damage precise quantification under varying environmental and operating conditions (EOCs), is investigated for the first time. The study examines a new concept of a 10 MW multibody FOWT whose tower is supported by a platform consisting of two rigid-body tanks connected by 12 tendons. Normal and the most severe EOCs from a site located in the northern coast of Scotland, are selected for the simulation of the FOWT structure under constant current but varying wind and wave conditions. Dynamic responses of the platform under different damage states are obtained based on the simulated FOWT. The damage scenarios are modelled via stiffness reduction (%) at the tendon's connection point to the platform's upper tank. Damage diagnosis is achieved via an advanced method, the Functional Model Based Method, that is formulated to operate using a single response signal and stochastic Functional Models representing the structural dynamics under the effects of varying EOCs and any magnitude of the considered damages. Due to the robustness and high number of the existing tendons, the effects of considered damages on the FOWT dynamics are minor and overlapped by the effects of the varying EOCs, indicating a highly challenging damage diagnosis problem. Very good damage detection results are obtained with the damage detection almost faultless and with no false alarms. Accurate tendon identification is achieved for the 95% of the considered test cases, while the mean error in damage quantification is approximately equal to 4% using measurements from just a si