Foreign Object Damage to Fan Rotor Blades of Aeroengine Part I: Experimental Study of Bird Impact

AbstractThe conditions of experiment for bird impact to blades have been improved. The experiment of bird impact to the fan rotor blades of an aeroengine is carried out. Through analyzing the transient state response of blades impacted by bird and the change of blade profile before and after the impact, the anti-bird impact performance of blades in the first fan rotor is verified. The basis of anti-foreign object damage design for the fan rotor blades of an aeroengine is provided

Foreign Object Damage to Fan Rotor Blades of Aeroengine Part II: Numerical Simulation of Bird Impact

AbstractBird impact is one of the most dangerous threats to flight safety. The consequences of bird impact can be severe and, therefore, the aircraft components have to be certified for a proven level of bird impact resistance before being put into service. The fan rotor blades of aeroengine are the components being easily impacted by birds. It is necessary to ensure that the fan rotor blades should have adequate resistance against the bird impact, to reduce the flying accidents caused by bird impacts. Using the contacting-impacting algorithm, the numerical simulation is carried out to simulate bird impact. A three-blade computational model is set up for the fan rotor blade having shrouds. The transient response curves of the points corresponding to measured points in experiments, displacements and equivalent stresses on the blades are obtained during the simulation. From the comparison of the transient response curves obtained from numerical simulation with that obtained from experiments, it can be found that the variations in measured points and the corresponding points of simulation are basically the same. The deforming process, the maximum displacements and the maximum equivalent stresses on blades are analyzed. The numerical simulation verifies and complements the experiment results

Effect of directional solidification rate on the microstructure and properties of deformation-processed Cu-7Cr-0.1Ag in situ composites

The influence of directional solidification rate on the microstructure, mechanical properties and conductivity of deformation-processed Cu-7Cr-0.1Ag in situ composites produced by thermo-mechanical processing was systematically investigated. The microstructure was analyzed by optical microscopy and scanning electronic microscopy. The mechanical properties and conductivity were evaluated by tensile-testing machine and micro-ohmmeter, respectively. The results indicate that the size, shape and distribution of second-phase Cr grains are significantly different in the Cu-7Cr-0.1Ag alloys with different growth rates. At a growth rate of 200 μm s-1, the Cr grains transform into fine Cr fiber-like grains parallel to the pulling direction from the Cr dendrites. The tensile strength of the Cu-7Cr-0.1Ag in situ composites from the directional solidification (DS) alloys is significantly higher than that from the as-cast alloy, while the conductivity of the in situ composites from the DS alloys is slightly lower than that from the as-cast alloy. The following combinations of tensile strength, elongation to fracture and conductivity of the Cu-7Cr-0.1Ag in situ composites from the DS alloy with a growth rate of 200 μm s-1 and a cumulative cold deformation strain of 8 after isochronic aging treatment for 1 h can be obtained respectively as: (i) 1067 MPa, 2.9% and 74.9% IACS; or (ii) 1018 MPa, 3.0%, and 76.0% IACS or (iii) 906 MPa, 3.3% and 77.6% IACS

Simultaneous dissipation of trichloroethene and arsenic from co-contaminated groundwater by coupling biodechlorination and biodetoxification with assistance of biochar

Co-contamination of groundwater with trichloroethene (TCE) and arsenic (As) is a widespread problem in industrial sites. The simultaneous biological removal of As and TCE has not yet been developed. This study incorporated biochar into anaerobic dechlorination system to achieve a greatly accelerated dissipation and co-removal of TCE and As. Biochar eliminated microbial lag (6 days) and achieved a 100% TCE removal within 12 days even at a relatively high initial concentration (TCE: 30 mg L−1; As(V): 4 mg L−1), while without biochar, only 75% TCE was removed until day 18. Biochar adsorbed TCE and the intermediate products allowing them to be degraded on its surface gradually, maintaining a high metabolic activity of microbes. Biochar facilitated the preferential colonization of its surfaces by dechlorinating microorganisms (Clostridium and Dehalococcoides) and suppressed hydrogen-competing microorganisms (Desulfovibrio) in water. Biochar itself cannot adsorb As, however, separation of biochar carrying the As-laden microorganisms achieved 50–70% As-removal from groundwater. The biochar-amended incubations were found to be enriched with microbes possessing more crucial As-transforming genes (K00537-arsC and K07755-AS3MT), and upregulated amino acid metabolism, thus enhancing the self-detoxification ability of microorganisms to transform As(V) to As(III) or volatile organic As. This study proposes a strategy of regulating microbes’ metabolic activity by biochar to achieve simultaneous removal of coexisting contaminations, which is an important step prior to examining the feasibility of biochar application for enhanced bioremediation. Graphical Abstract: [Figure not available: see fulltext.]</p

Comparison of perioperative outcomes among non-small cell lung cancer patients with neoadjuvant immune checkpoint inhibitor plus chemotherapy, EGFR-TKI, and chemotherapy alone: A real-world evidence study

Background: The utilization of neoadjuvant immune checkpoint inhibitor (ICI) plus chemotherapy has increased significantly for resectable non-small cell lung cancer (NSCLC). It is still unclear whether such a treatment paradigm affects perioperative outcomes compared with other neoadjuvant treatment. We aimed to evaluate the perioperative outcomes of pulmonary resection after neoadjuvant ICI plus chemotherapy and to compare them with neoadjuvant epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKI) and neoadjuvant chemotherapy alone for resectable NSCLC. Methods: A retrospective cohort including 194 stage IB-IIIB NSCLC underwent surgical resection after neoadjuvant treatment between 2018 and 2020 were reviewed. Perioperative complications were evaluated using the Common Terminology Criteria for Adverse Events, and were compared using one-way analysis of variance for continuous variables and Pearson chi-square test. Results: There were 42, 54, and 98 patients in the neoadjuvant ICI plus chemotherapy, EGFR-TKI, and chemotherapy alone groups, respectively. The tumor size before neoadjuvant treatment was well balanced among the three groups (P=0.122). A shorter median surgical time was observed in the EGFR-TKI group than ICI plus chemotherapy group and chemotherapy group alone (120 Conclusions: Surgical resection for NSCLC following neoadjuvant ICI plus chemotherapy was safe and feasible, the perioperative outcomes were similar with neoadjuvant EGFR-TKI and chemotherapy alone without unexpected perioperative complications. Additional prospective studies are necessary to validate our findings

Enhanced heating rate of black carbon above planetary boundary layer over megacities in summertime

The fast development of a secondary aerosol layer was observed over megacities in eastern Asia during summertime. Within three hours, from midday to early afternoon, the contribution of secondary aerosols above the planetary boundary layer (PBL) increased by a factor of 3-5, and the coatings on the black carbon (BC) also increased and enhanced its absorption efficiency by 50%. This tended to result from the intensive actinic flux received above the PBL which promoted the photochemical reactions. The absorption of BC could be further amplified by the strong reflection of solar radiation over the cloud top across the PBL. This enhanced heating effect of BC introduced by combined processes (intensive solar radiation, secondary formation and cloud reflection) may considerably increase the temperature inversion above the PBL. This mechanism should be considered when evaluating the radiative impact of BC, especially for the polluted regions receiving strong solar radiation

Fungal diversity notes 929–1035: taxonomic and phylogenetic contributions on genera and species of fungi

This article is the ninth in the series of Fungal Diversity Notes, where 107 taxa distributed in three phyla, nine classes, 31 orders and 57 families are described and illustrated. Taxa described in the present study include 12 new genera, 74 new species, three new combinations, two reference specimens, a re-circumscription of the epitype, and 15 records of sexualasexual morph connections, new hosts and new geographical distributions. Twelve new genera comprise Brunneofusispora, Brunneomurispora, Liua, Lonicericola, Neoeutypella, Paratrimmatostroma, Parazalerion, Proliferophorum, Pseudoastrosphaeriellopsis, Septomelanconiella, Velebitea and Vicosamyces. Seventy-four new species are Agaricus memnonius, A. langensis, Aleurodiscus patagonicus, Amanita flavoalba, A. subtropicana, Amphisphaeria mangrovei, Baorangia major, Bartalinia kunmingensis, Brunneofusispora sinensis, Brunneomurispora lonicerae, Capronia camelliaeyunnanensis, Clavulina thindii, Coniochaeta simbalensis, Conlarium thailandense, Coprinus trigonosporus, Liua muriformis, Cyphellophora filicis, Cytospora ulmicola, Dacrymyces invisibilis, Dictyocheirospora metroxylonis, Distoseptispora thysanolaenae, Emericellopsis koreana, Galiicola baoshanensis, Hygrocybe lucida, Hypoxylon teeravasati, Hyweljonesia indica, Keissleriella caraganae, Lactarius olivaceopallidus, Lactifluus midnapurensis, Lembosia brigadeirensis, Leptosphaeria urticae, Lonicericola hyaloseptispora, Lophiotrema mucilaginosis, Marasmiellus bicoloripes, Marasmius indojasminodorus, Micropeltis phetchaburiensis, Mucor orantomantidis, Murilentithecium lonicerae, Neobambusicola brunnea, Neoeutypella baoshanensis, Neoroussoella heveae, Neosetophoma lonicerae, Ophiobolus malleolus, Parabambusicola thysanolaenae, Paratrimmatostroma kunmingensis, Parazalerion indica, Penicillium dokdoense, Peroneutypa mangrovei, Phaeosphaeria cycadis, Phanerochaete australosanguinea, Plectosphaerella kunmingensis, Plenodomus artemisiae, P. lijiangensis, Proliferophorum thailandicum, Pseudoastrosphaeriellopsis kaveriana, Pseudohelicomyces menglunicus, Pseudoplagiostoma mangiferae, Robillarda mangiferae, Roussoella elaeicola, Russula choptae, R. uttarakhandia, Septomelanconiella thailandica, Spencermartinsia acericola, Sphaerellopsis isthmospora, Thozetella lithocarpi, Trechispora echinospora, Tremellochaete atlantica, Trichoderma koreanum, T. pinicola, T. rugulosum, Velebitea chrysotexta, Vicosamyces venturisporus, Wojnowiciella kunmingensis and Zopfiella indica. Three new combinations are Baorangia rufomaculata, Lanmaoa pallidorosea and Wojnowiciella rosicola. The reference specimens of Canalisporium kenyense and Tamsiniella labiosa are designated. The epitype of Sarcopeziza sicula is re-circumscribed based on cyto- and histochemical analyses. The sexual-asexual morph connection of Plenodomus sinensis is reported from ferns and Cirsium for the first time. In addition, the new host records and country records are Amanita altipes, A. melleialba, Amarenomyces dactylidis, Chaetosphaeria panamensis, Coniella vitis, Coprinopsis kubickae, Dothiorella sarmentorum, Leptobacillium leptobactrum var. calidus, Muyocopron lithocarpi, Neoroussoella solani, Periconia cortaderiae, Phragmocamarosporium hederae, Sphaerellopsis paraphysata and Sphaeropsis eucalypticola

Cardiovascular and safety events of PCSK9 inhibitors in statin-treated patients with cardiovascular risk: A Systematic Review and Meta-Analysis

Objectives: To evaluate whether proprotein convertase subtilisin/kexin type 9 inhibitor (PCSK9i) is associated with cardiovascular and safety events in statin-treated patients with cardiovascular risk. Methods: Electronic databases (Pubmed, Cochrane, MEDLINE, EMBASE, ClinicalTrials.gov) were searched through March 31, 2020. Included randomized clinical trials (RCTs) compared PCSK9i use with no PCSK9i in statin treated patients. Two investigators abstracted data and appraised risks of bias. A meta-analysis was performed to calculate risk ratios (RRs) and 95% CIs using fix-effects models. Adjudicated cardiovascular events (CVE) and adverse drug events (ADE) were defined as the primary outcome. Secondary outcomes were cardiovascular (CV) death, all-cause death, nonfatal myocardial infarction, ischemic stroke, serious ADE and injection-site reaction. Results: A total of 10 RCTs 50 053 participants were included. PCSK9i use was associated with signigicant reductions in the CVE (RR, 0.87 [95%CI, 0.83-0.91]; NNT, 54; P<0.00001; I2=0%, heterogeneity P=0.86), nonfatal myocardial infarction (RR, 0.86 [95% CI, 0.78-0.96]; NNT, 95; P=0.005; I2=0%, heterogeneity P=0.88), and ischemic stroke (RR, 0.75 [95%CI 0.64-0.87]; NNT, 244; P=0.00; I2=0%, heterogeneity P=0.82) compared with no PCSK9i in statin-treated patients with CV risk. No significant associations were found between PCSK9i use and no PCSK9i in ADE and serious ADE. PCSK9i use was associated with signigicant increasing in injection-site reaction (RR, 1.55 [95%CI 1.38-1.75]; NNT, 101; P<0.00001; I2=0%, heterogeneity P=0.44). Conclusions: Among statin-treated patients with CV risk, the use of PCSK9i was associated with improving CV outcomes. The use of PCSK9i was well tolerated, but had significantly injection-site reactions