443 research outputs found

    Effects of vane/blade ratio and spacing on fan noise, volume 1

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    The noise characteristics of a high-speed fan were studied. The experimental investigation was carried out on a 50.8 cm (20 in.) diameter scale model fan stage in an anechoic chamber with an inflow turbulence control screen installed. The forty-four blade rotor was tested with forty-eight vane and eighty-six vane stator rows, over a range of aixal rotor-stator spacings from 0.5 to 2.3 rotor tip chords. A two-dimensional strip theory model of rotor-stator interaction noise was employed to predict the measured tone power level trends, and good overall agreement with measured trends was obtained

    Basic research in fan source noise: Inlet distortion and turbulence noise

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    A widely recognized problem in jet engine fan noise is the discrepancy between inflight and static tests. This discrepancy consists of blade passing frequency tones, caused by ingested turbulence that appear in the static tests but not in flight. To reduce the ingested distortions and turbulence in an anechoic chamber, a reverse cone inlet is used to guide the air into the fan. This inlet also has provisions for boundary layer suction and is used in conjunction with a turbulence control structure (TCS) to condition the air impinging on the fan. The program was very successful in reducing the ingested turbulence, to the point where reductions in the acoustic power at blade passing frequency are as high as 18 db for subsonic tip speeds. Even with this large subsonic tone suppression, the supersonic tip speed tonal content remains largely unchanged, indicating that the TCS did not appreciably attenuate the noise but effects the generation via turbulence reduction. Turbulence mapping of the inlet confirmed that the tone reductions are due to a reduction in turbulence, as the low frequency power spectra of the streamwise and transverse turbulence were reduced by up to ten times and 100 times, respectively

    Effects of vane/blade ratio and spacing on fan noise. Volume 2: Data supplement

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    Complete tabulations of 1/3-octave band acoustic measurements are given

    MARS therapy, the bridging to liver retransplantation-Three cases from the Hungarian liver transplant program

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    Besides orthotopic liver transplantation (OLT) there is no long-term and effective replacement therapy for severe liver failure. Artificial extracorporeal liver supply devices are able to reduce blood toxin levels, but do not replace any synthetic function of the liver. Molecular adsorbent recirculating system (MARS) is one of the methods that can be used to treat fulminant acute liver failure (ALF) or acute on chronic liver failure (AoCLF). The primary non-function (PNF) of the newly transplanted liver manifests in the clinical settings exactly like acute liver failure. MARS treatment can reduce the severity of complications by eliminating blood toxins, so that it can help hepatic encephalopathy (HE), hepatorenal syndrome (HRS), and the high rate mortality of cerebral herniation. This might serve as a bridging therapy before orthotopic liver retransplantation (reOLT). Three patients after a first liver transplantation became candidate for urgent MARS treatment as a bridging solution prior to reOLT in our center. Authors report these three cases, focusing on indications, MARS sessions, clinical courses, and final outcomes. © 2013 Akadémiai Kiadó, Budapest

    Natural course of Fabry disease with the p Arg227Ter (pR227*) mutation in Finland: Fast study

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    BackgroundFabry disease is caused by a deficient or an absent alfa‐galactosidase A activity and is an X‐linked disorder that results in organ damage and a shortened life span, especially in males. The severity of the disease depends on the type of mutation, gender, skewed X‐chromosome inactivation, and other still unknown factors.MethodsIn this article, we describe the natural course of a common classic Fabry disease mutation, p.Arg227Ter or p.R227*, in Finland.ResultsFour males and ten females belonged to two extended families. The mean age was 46 years (SD 18.4). Six patients (43%) had cardiac hypertrophy, three patients (21%) had ischemic stroke, and none had severe kidney dysfunction. Three patients had atrial fibrillation; two patients who had atrial fibrillation also had pacemakers. All males over 30 years of age had at least one of the following manifestations: cardiac hypertrophy, stroke, or proteinuria. In females, the severity of Fabry disease varied from classic multiorgan disease to a condition that mimicked the attenuated cardiac variant. No one was totally asymptomatic without any signs of Fabry disease. Cardiac magnetic resonance imaging was performed on nine of 14 patients was the most sensitive for detecting early cardiac manifestations. Five patients (55%) had late gadolinium enhancement‐positive segments.ConclusionCardiac involvement should be effectively detected in females before considering them asymptomatic mutation carriers.</div

    Affordances, constraints and information flows as ‘leverage points’ in design for sustainable behaviour

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    Copyright @ 2012 Social Science Electronic PublishingTwo of Donella Meadows' 'leverage points' for intervening in systems (1999) seem particularly pertinent to design for sustainable behaviour, in the sense that designers may have the scope to implement them in (re-)designing everyday products and services. The 'rules of the system' -- interpreted here to refer to affordances and constraints -- and the structure of information flows both offer a range of opportunities for design interventions to in fluence behaviour change, and in this paper, some of the implications and possibilities are discussed with reference to parallel concepts from within design, HCI and relevant areas of psychology

    Cardiovascular Events in Patients With Fabry Disease Natural History Data From the Fabry Registry

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    ObjectivesThese analyses were designed to determine the incidence of major cardiovascular (CV) events and the natural history of CV complications in patients with Fabry disease.BackgroundFabry disease, a genetic disorder caused by deficiency of alpha-galactosidase A activity, is associated with CV dysfunction.MethodsMajor CV events (myocardial infarction, heart failure, or cardiac-related death) were analyzed in 2,869 Fabry Registry patients during the natural history period (i.e., before enzyme replacement therapy or among patients who never received therapy). Multivariate logistic regression analyses were performed to identify significant predictors of CV events.ResultsEighty-three of 1,424 men (5.8%) and 54 of 1,445 women (3.7%) experienced CV events at mean ages of 45 and 54 years, respectively. Heart failure was the most common first CV event, reported by 50 men (3.5%) and 33 women (2.3%). Hypertension and left ventricular hypertrophy were the risk factors most strongly associated with CV events. When these parameters were used as covariates in logistic regression analyses, the odds ratio (OR) for hypertension in men was 7.8 (95% confidence interval [CI]: 2.1 to 28.6, p = 0.0019), and the OR for hypertension in women was 4.5 (95% CI: 1.6 to 12.3, p = 0.0037). The OR for left ventricular hypertrophy was 4.8 in men (95% CI: 1.03 to 22.2, p = 0.0463) and 8.2 in women (95% CI: 2.6 to 26.0, p = 0.0003).ConclusionsMajor CV events occurred in approximately 5% of Fabry Registry patients during the natural history period. All patients with Fabry disease should be monitored for possible CV risk factors, particularly hypertension and left ventricular hypertrophy

    The long and short of it: the temporal significance of wealth and income

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    In the literatures on the lived experience of poverty and richness temporal dimensions are underappreciated. Comparing qualitative interviews with those at opposite ends of the income and wealth distributions in the UK, we examine a temporal contrast: while “poor” participants experience money as flows of income which focus orientation to the present and constrain orientation to the future, “rich” participants experience money not only as flows of income, but also in the form of a stock of wealth which facilitates long-term orientations. Highlighting the enduring nature of wealth and the comparative short-termism of income, we argue that the way in which capital and income relates to individuals' orientations to the future is important for understanding how economic inequality is experienced. Put differently, the form which economic resources take matters for one's ability to plan and control the future. This insight contributes to our understanding of the experience of being economically advantaged or disadvantaged, with implications for (social) policy

    Tumour invasiveness, the local and systemic environment and the basis of staging systems in colorectal cancer

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    background: The present study aimed to examine the relationship between tumour invasiveness (T stage), the local and systemic environment and cancer-specific survival (CSS) of patients with primary operable colorectal cancer. methods: The tumour microenvironment was examined using measures of the inflammatory infiltrate (Klintrup-Makinen (KM) grade and Immunoscore), tumour stroma percentage (TSP) and tumour budding. The systemic inflammatory environment was examined using modified Glasgow Prognostic Score (mGPS) and neutrophil:lymphocyte ratio (NLR). A 5-year CSS was examined. results: A total of 331 patients were included. Increasing T stage was associated with colonic primary, N stage, poor differentiation, margin involvement and venous invasion (P&lt;0.05). T stage was significantly associated with KM grade (P=0.001), Immunoscore (P=0.016), TSP (P=0.006), tumour budding (P&lt;0.001), and elevated mGPS and NLR (both P&lt;0.05). In patients with T3 cancer, N stage stratified survival from 88 to 64%, whereas Immunoscore and budding stratified survival from 100 to 70% and from 91 to 56%, respectively. The Glasgow Microenvironment Score, a score based on KM grade and TSP, stratified survival from 93 to 58%. conclusions: Although associated with increasing T stage, local and systemic tumour environment characteristics, and in particular Immunoscore, budding, TSP and mGPS, are stage-independent determinants of survival and may be utilised in the staging of patients with primary operable colorectal cancer
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