Time-Averaged Aerodynamics of a High-Speed Low-Pressure Turbine Cascade With Cavity Purge and Unsteady Wakes

editorial reviewedThe time-averaged aerodynamics of a high-speed low-pressure turbine (LPT) cascade were investigated under the impact of unsteady wakes and purge flows. The tests were performed at an outlet Mach (M) and Reynolds numbers (Re) of 0.90 and 70 k, respectively. Unsteady wakes were simulated by means of a spoked-wheel type wake generator (WG), and a reduced frequency of 0.95 was achieved. The development of a purge flow system to operate at low-pressure levels is presented alongside guidelines for the operation of the circuit. The new purge system was commissioned in terms of its long-term stability and flow uniformity at the cascade inlet. The impact of varying purge flows from a cavity versus a flat endwall was assessed by means of static pressure measurements on the blade pressure side (PS) and suction side (SS) and traverses performed downstream with a miniaturized multi-hole probe. Differences in the secondary flow structures resultant from injecting purge flow into the flowfield are observed, namely, the intensification of the trailing shed vortex (TSV) and passage vortex (PV) that is also displaced away from the endwall. An increase of the endwall losses occurs as the flat endwall was replaced with a cavity geometry and the cavity purge flowrate increases

Incidence of complications in bronchoscopy. Multicentre prospective study of 20,986 bronchoscopies.

Aim. To evaluate the frequency of complications in bronchoscopy from data compiled between 1/2/2002 to 1/2/2003. Materials and methods. Nineteen Italian centres of thoracic endoscopy participated in the study, for a total of 20,986 bronchoscopies (FBS), including 10,658 explorative bronchoscopies (EB) (50.79%), 5,520 bronchial biopsies (BB) (26.30%), 1,660 transbronchial biopsies (TBB) (7.91%), 1,127 broncho-alveolar lavages (BAL) (5.37%), 930 transbronchial needle-aspirates (TBNA) (4.43%), 1.091 therapeutic bronchoscopies (TB), comprising NDYAG Laser, argon-plasma, electrocautery knife, stent insertion (5.20%). 82.4% of the procedures involved the use of a flexible bronchoscope, 16.3% were carried out using a rigid bronchoscope and 1.3% using the mixed technique. Results. The total number of complications recorded was 227 (1.08% of the cases examined), including 20 (0.09%) during local anesthesia and pre-medication, 195 (0.92%) during the endoscopic procedures and 12 (0.05%) in the two hours following FBS. The total number of deaths was 4 (0.02%), due to cardiac arrest, pulmonary edema, delayed respiratory failure and shock in pre-medication, respectively. 68.28% of the complications were treated medically, 25.99% by means of endoscopy and 5.72% with surgery. The healing percentage was 98.2%. Conclusions. This study has shown that bronchoscopy is a safe method with low incidence of mortality and complications. The preparation, experience and continuous training of the operators of the medical and nursing team seem to play a fundamental role in reducing the incidence of complications at least in certain procedures such as BB and TBB

Análisis comparativo de los condicionantes académico-institucionales para la permanencia de los alumnos durante el primer año de carreras universitarias del área de las ciencias químicas y de las ciencias humanas.

El ingreso a la vida universitaria supone un complejo proceso multifactorial, en el cual intervienen varios aspectos tanto del ingresante como del entorno.  Entre estos factores se encuentran los condicionantes académico-institucionales.  Los mismos indican como objeto de estudio a los eventos del aula de nivel superior de enseñanza en su dimensión pedagógico-didáctica

Nycthemeral and Monthly Occupation of the Fish Assemblage on a Sheltered Beach of Baía Norte, Florianópolis, Santa Catarina State, Brazil

Interpreting fish community records is challenging for several reasons, including the lack of past ichthyofauna data, the cyclical temporal variations in the community, and the methodology employed, which usually underestimates fish assemblages. The objective of this study was to describe short-scale and meso-scale (nycthemeral period and months, respectively) temporal variations in the ichthyofauna composition and structure of a sheltered beach of Baía Norte (Florianópolis, Santa Catarina state, Brazil), using a capéchade net. Samples were collected monthly for a period of 48 hours. During the period from December 2010 to November 2011, a total of 19,302 individuals belonging to 89 species and 39 families were captured. The number of individuals that were sampled during the day and/or night was dependent on the sampling month. On average, the daytime assemblage was more abundant and different in structure and composition than the nighttime assemblage. Of the eight species that had the highest Index of Relative Importance (%IRI), five had higher variations (ANOVA F) between the day and night than between the months. This finding reinforced the need for sampling during both the day and night. The capéchade net effectively captured demersal and pelagic individuals in a broad range of sizes

Fish assemblages in a coastal bay adjacent to a network of marine protected areas in southern Brazil

Abstract Baía Norte (North Bay) in Santa Catarina State is considered a typical coastal bay and is surrounded by a network of Marine Protected Areas. The objectives of this study were to describe the composition of the demersal fish assemblage, identify seasonal and spatial structures on a fine scale and evaluate the role of habitat descriptors and abiotic variables affecting the fish assemblage structure. Seasonal samplings were conducted in 2005, using bottom trawls in six pre-established areas in Baía Norte in summer, fall, winter and spring. Simultaneously with each trawl, environmental data were collected with a multiparameter probe. Temporal and spatial differences in fish abundance were tested by a PERMANOVA. To illustratethe differences detected graphically we ran a canonical analysis of principal coordinates (CAP). The influence of environmental variables on the fish fauna was evaluated using a Distant Based Linear Model (DistLM) with Akaike's information criterion (AIC). A total of 9,888 specimens, distributed in 27 families and 62 species, were collected. Citharichthys spilopterus was the most abundant species. PERMANOVA detected differences for abundance between seasons, areas and interaction among all the factors. The DISTLM selected temperature and pH. The results highlight seasonality as an important factor in the structuring of fish fauna of the study place

Protective intraoperative ventilation with higher versus lower levels of positive end-expiratory pressure in obese patients (PROBESE): study protocol for a randomized controlled trial

Background: Postoperative pulmonary complications (PPCs) increase the morbidity and mortality of surgery in obese patients. High levels of positive end-expiratory pressure (PEEP) with lung recruitment maneuvers may improve intraoperative respiratory function, but they can also compromise hemodynamics, and the effects on PPCs are uncertain. We hypothesized that intraoperative mechanical ventilation using high PEEP with periodic recruitment maneuvers, as compared with low PEEP without recruitment maneuvers, prevents PPCs in obese patients. Methods/design The PRotective Ventilation with Higher versus Lower PEEP during General Anesthesia for Surgery in OBESE Patients (PROBESE) study is a multicenter, two-arm, international randomized controlled trial. In total, 2013 obese patients with body mass index ≥35 kg/m2 scheduled for at least 2 h of surgery under general anesthesia and at intermediate to high risk for PPCs will be included. Patients are ventilated intraoperatively with a low tidal volume of 7 ml/kg (predicted body weight) and randomly assigned to PEEP of 12 cmH2O with lung recruitment maneuvers (high PEEP) or PEEP of 4 cmH2O without recruitment maneuvers (low PEEP). The occurrence of PPCs will be recorded as collapsed composite of single adverse pulmonary events and represents the primary endpoint. Discussion To our knowledge, the PROBESE trial is the first multicenter, international randomized controlled trial to compare the effects of two different levels of intraoperative PEEP during protective low tidal volume ventilation on PPCs in obese patients. The results of the PROBESE trial will support anesthesiologists in their decision to choose a certain PEEP level during general anesthesia for surgery in obese patients in an attempt to prevent PPCs. Trial registration ClinicalTrials.gov identifier: NCT02148692. Registered on 23 May 2014; last updated 7 June 2016. Electronic supplementary material The online version of this article (doi:10.1186/s13063-017-1929-0) contains supplementary material, which is available to authorized users

Instrumentation Interference in a Transonic Linear Cascade

editorial reviewedA major challenge when testing high-speed flows in turbomachinery applications concerns instrumentation intrusiveness. The current work exposes the impact of aerodynamic probes, placed upstream and downstream of the testing article, on the aerodynamics of a transonic low-pressure turbine blade investigated in a linear cascade at engine-representative outlet Mach and Reynolds numbers. The effect of a probe placed downstream of the cascade can be perceived as far as to the inlet of the cascade. The quantification of the probe impact is presented on the blade loading as well as on the instrumentation placed upstream and downstream of the cascade used to monitor the operating conditions during testing. It is shown that the presence of the probe can be partially compensated. The impact of this aerodynamic compensation on the cascade loss is reported.Secondary and Leakage Flow Effects in High-SPeed Low-PrEssurE TurbiNe

AN EXPERIMENTAL TEST CASE FOR TRANSONIC LOW-PRESSURE TURBINES - PART 2: CASCADE AERODYNAMICS AT ON- AND OFF-DESIGN REYNOLDS AND MACH NUMBERS

peer reviewedIn this two-part paper, a novel test-case for transonic low-pressure turbines (LPT) is presented. The current study is a comprehensive report on the design, commissioning and testing of a high-speed LPT cascade. Part II reports the characterization of the aerodynamics at on- and off-design flow conditions. A detailed analysis of the steady aerodynamics of the high-speed low-pressure turbine blade is presented for a range of engine representative outlet Mach numbers from 0.70 to 0.95 and Reynolds numbers from 65,000 to 120,000. The blade 3D aerodynamics are characterized using an innovative set of traversable blades, enabling high-resolution radial measurements. A novel method to estimate the location of separation-reattachment based on pneumatic tap measurements is presented. The separation on the blade suction side is strongly influenced by the Reynolds number at the lower Mach numbers, while open separations were observed at transonic exit conditions independently on the Reynolds number. Downstream measurements by means of a five-hole probe, and pressure taps located in the passage endwall are employed to study the secondary flow development and structures at the cascade outlet. The results show that the losses follow different trends at high and low Reynolds numbers. The profile losses at Re = 70k decrease with increasing Mach number, contrary to what is observed for Re = 120k. The minimum secondary flow losses are found for an off-design condition with lower Mach number with respect to the nominal. The off-design comparisons presented in this paper indicate that at low Reynolds, operating at transonic outlet Mach numbers leads to beneficial effects on the performance

IL15 induces a potent antitumor activity in NK cells isolated from malignant pleural effusions and overcomes the inhibitory effect of pleural fluid

Natural Killer (NK) cells are capable of recognizing and killing cancer cells and play an important role in tumor immunosurveillance. However, tumor-infiltrating NK cells are frequently impaired in their functional capability. A remarkable exception is represented by NK cells isolated from malignant pleural effusions (PE) that are not anergic and, upon IL2-induced activation, efficiently kill tumor cells. Although IL2 is used in various clinical trials, severe side effects may occur in treated patients. In this study, we investigated whether also other clinical-grade cytokines could induce strong cytotoxicity in NK cells isolated from pleural fluid of patients with primary or metastatic tumors of different origins. We show that PE-NK cells, cultured for short-time intervals with IL15, maintain the CD56brightphenotype, a high expression of the main activating receptors, produce cytokines and kill tumor cells in vitro similarly to those treated with IL2. Moreover, IL15-activated PE-NK cells could greatly reduce the growth of established tumors in mice. This in vivo antitumor effect correlated with the ability of IL15-activated PE-NK cells to traffic from periphery to the tumor site. Finally, we show that IL15 can counteract the inhibitory effect of the tumor pleural microenvironment. Our study suggests that IL15-activated NK cells isolated from pleural fluid (otherwise discarded after thoracentesis) may represent a suitable source of effector cells to be used in adoptive immunotherapy of cancer