Modal Analysis for Crack Detection in Small Wind Turbine Blades

The aim of the present paper is to evaluate structural health monitoring (SHM) techniques based on modal analysis for crack detection in small wind turbine blades. A finite element (FE) model calibrated to measured modal parameters will be introduced to cracks with different sizes along one edge of the blade. Changes in modal parameters from the FE model are compared with data obtained from experimental tests. These comparisons will be used to validate the FE model and subsequently discuss the usability of SHM techniques based on modal parameters for condition monitoring of wind turbine blades.</jats:p

RESEARCH ARTICLE Risk and Prognosis of Bloodstream Infections among Patients on Chronic Hemodialysis: A Population-Based Cohort Study

Background and Objectives Infections are common complications among patients on chronic hemodialysis. This population-based cohort study aims to estimate risk and case fatality of bloodstream infec-tion among chronic hemodialysis patients. Methods In this population-based cohort study we identified residents with end-stage renal disease in Central and North Jutland, Denmark who had hemodialysis as first renal replacement therapy (hemodialysis patients) during 1995–2010. For each hemodialysis patient, we sam-pled 19 persons from the general population matched on age, gender, and municipality. In-formation on positive blood cultures was obtained from regional microbiology databases. All persons were observed from cohort entry until first episode of bloodstream infection, emi-gration, death, or end of hemodialysis treatment, whichever came first. Incidence-rates and incidence-rate ratios were computed and risk factors for bloodstream infection assessed by Poisson regression. Case fatality was compared by Cox regression

Cumulative case fatality following first episode of bloodstream infection in hemodialysis patients and a matched control population by type of microorganism.

<p>Cumulative case fatality following first episode of bloodstream infection in hemodialysis patients and a matched control population by type of microorganism.</p

Incidence rates of first episodes of bloodstream infection among hemodialysis patients and a matched comparison population, 1995–2010.

<p>Abbreviations: CI, confidence interval; IRR, incidence rate ratio.</p><p>^a Number of first episodes of bacteremia.</p><p>^b Years.</p><p>^c Per 100 person-years.</p><p>^d Adjusted for age, gender, and level of comorbidity. In the overall group also adjusted for time since study entry using Poisson regression.</p><p>Incidence rates of first episodes of bloodstream infection among hemodialysis patients and a matched comparison population, 1995–2010.</p

Study population.

<p>Overview.</p