Experimental verification of predicted capability of a wind turbine drivetrain test bench to replicate dynamic loads onto multi-megawatt nacelles

A total of 27 test profiles from the IEC 61400-1 design load cases were tested using a 7.5-MW wind turbine drivetrain test bench and two multi-megawatt wind turbine drivetrains. Each test profile consisted of simultaneous vertical, lateral, and longitudinal forces, yawing and nodding bending moment, and rotational speed. These test-bench inputs were compared with the forces, bending moments, and speed that were applied to the wind turbine drivetrains to quantify the test-bench tracking error. This tracking error was quantified for a range of ramp-rate limits of the yawing and nodding bending moments. The experimental results were compared with predictions from an evaluation method for the capability of wind turbine drivetrain test benches to replicate dynamic loads. The method’s predictive capability was found to be sufficient for the goal of early screening and its formulation is applicable to any wind turbine drivetrain test bench and drivetrain design.

Aspergillus test profiles and mortality in critically-ill COVID-19 patients

Background The literature regarding COVID-19 associated pulmonary aspergillosis (CAPA) has shown conflicting observations, including survival of CAPA patients not receiving antifungal therapy and discrepancy between CAPA diagnosis and autopsy findings. To gain insight into the pathophysiology of CAPA we performed a case-control study, in which we compared Aspergillus test profiles in CAPA patients and controls in relation to ICU-mortality. Methods A multinational case-control study, in which Aspergillus test results, use of antifungal therapy and mortality were collected from critically-ill COVID-19 patients. Patients were classified using the 2020 ECMM/ISHAM consensus case definitions. Results 219 critically-ill COVID-19 cases were analyzed, including one proven, 38 probable, 19 possible CAPA cases, 21 Aspergillus colonized patients, seven patients only positive for serum (1, 3)-ß-D-glucan (BDG), and 133 cases with no evidence of CAPA. Mortality was 53.8% in CAPA patients compared to 24.1% in patients without CAPA (p=0.001). Positive serum galactomannan (GM) and BDG were associated with increased mortality compared to serum biomarker negative CAPA patients (87.5% versus 41.7%, p=0.046; 90.0% versus 42.1%, p=0.029, respectively). For each point increase in GM or ten-point BDG serum concentration, the odds of death increased (GM, OR 10.208, 95%CI 1.621-64.291, p=0.013; BDG, OR 1.247, 95%CI 1.029-1.511, p=0.024). Conclusions CAPA is a complex disease, probably involving a continuum of respiratory colonization, tissue-invasion and angioinvasion. Serum biomarkers are useful for staging CAPA disease progression and, if positive, indicate angioinvasion and a high probability of mortality. There is need for a biomarker that distinguishes between respiratory tract colonization and tissue invasive CAPA disease.

EXPRESS: Reducing neonatal phlebotomy blood losses through the accurate calculation of minimum test volume requirements

Background: Repeated phlebotomy for laboratory diagnostic testing is a known cause of iatrogenic anaemia and in critically ill neonates often leads to blood transfusion being required. This study has developed a spreadsheet clinical decision support (CDS) tool to allow neonatal staff to determine the true minimum blood volume (MBV) required to analyse groups of blood tests and modelled its potential benefit compared to the existing system in use. Methods: The tool calculates the MBV accounting for novel factors including the current patient haematocrit for plasma/serum samples, instrument minimum test and dead volumes (including those where shared) and sharing of samples within/between laboratory departments. A year of neonatal unit laboratory requests were examined comparing the volumes and containers of blood recommended by the hospital information system (HIS) with both the amount actually collected by staff and that recommended by the tool. Results: 463 patients had 8,481 blood draws for 23,899 tests or test profiles over the year. The HIS recommended collecting 11,222mL of blood into 18,509 containers, while 17,734 containers were actually received (10,717mL if fully filled). The tool recommended collecting 4,915mL of blood into 15,549 containers. Conclusions: This tool allows NICU staff to objectively determine the MBV required for a combination of tests and is generalisable between laboratory instruments. Compared to the HIS, use of the MBV-CDS tool could maximally reduce the volume of blood collected from this neonatal unit by more than a half. NICU staff had apparently already gone some way to determining their own minimum volumes required.

Acceptance criteria for the tracking error of wind turbine drivetrain test bench when replicating dynamic loads

A 7.5-MW wind turbine drivetrain test bench has been used to apply dynamic loads from IEC 61400-1 design load cases to a multi-MW wind turbine drivetrain. A total of 15 test profiles were tested with each test profile demanding the simultaneous application of vertical, lateral, and longitudinal forces, yawing and nodding bending moments, and rotational speed. These inputs to the test bench were compared with the forces, bending moments, and speed that were applied to the wind turbine drivetrain to quantify the tracking error of the test bench and cross-coupling between forces and bending moments. The effect of the tracking error and cross-coupling on the dynamic response of the test article was quantified using multibody simulation. The tracking error was found not to significantly change the dynamic response of the drivetrain. The experimental and simulation results are used to recommend acceptance criteria for the tracking error when replicating dynamic loads.

Polypropylene matrix composite with charcoal filler

Purpose: The aim of the article is to present the thermal, electrical and mechanical properties of the produced polymer composites with a filler in the form of charcoal powder. Design/methodology/approach: The tests were carried out on samples of pure polypropylene (PP) and polymer composites, the matrix of which is polypropylene (PP), and the filler was charcoal powder with a volume fraction of 10%, 20%, 30%, 40% and 50%. The tested polymer composites in the form of granules were produced by extrusion, and then standardised test profiles were made by injection moulding. Findings: The hardness of the tested composites was determined by the Shore D method, the grain size distribution of the filler used was determined using the laser method and its thermal stability was tested using the TGA thermogravimetric analysis. The volume and surface resistivity were also determined and the density was determined. It was found that the charcoal powder used as a filler is characterised by high thermal stability – up to 600°C – and with an increase in its volume share in the polymer matrix, the hardness and density of the produced composites increases. Practical implications: The tested composites can be used as structural composites for complex elements requiring high hardness and strength. Originality/value: The research results indicate the possibility of using charcoal as a filler in polymer matrix, which, due to its low production cost, may be an alternative to expensive carbon fillers.

Increased risk of psychopathological abnormalities in subjects with unilateral hearing loss: A cross-sectional study

Objective. Although unilateral hearing loss (UHL) has been proven to be associated with educational and behavioral problems, there are few studies on psychopathological abnormalities in this population. The aim of this study was to evaluate the psychopathological influence of UHL among Korean 19-year-old males.Methods. The authors retrospectively compared the objective personality test profiles of 602 subjects with UHL with those of 23,790 normal hearing peers. All participants in the current study were 19-year-old males who underwent physical examination and investigated the Korean Military Multiphasic Personality Inventory for conscription at the Military Manpower Administration from February 2015 to December 2016.Results. The neurosis scales revealed significantly higher scores in the UHL group as compared to the normal hearing group (50.9

Vestibular migraine presenting with acute peripheral vestibulopathy: Clinical, oculographic and vestibular test profiles

To describe clinical, oculographic and vestibular test profiles in patients with vestibular migraine (VM) who presented with acute peripheral vestibulopathy. VM was diagnosed according to Bárány Society or Neuhauser criteria. Neuro-otological examination, video-head impulse tests (v-HIT), cervical and ocular vestibular-evoked myogenic potentials (cVEMP/oVEMP), subjective visual horizontal (SVH) and audiometry were undertaken. Ten patients presented with prolonged vertigo. All had primary position unidirectional horizontal spontaneous nystagmus (mean slow-phase velocity 9.6 ± 7.0°). Horizontal canal vestibulo-ocular reflex was reduced in all (mean gain 0.54 ± 0.2) with refixation saccades (cumulative amplitude 6.4 ± 3.2°). Abnormality rates for cVEMP, oVEMP and SVH were 30%, 80%, 78%, respectively. Magnetic resonance imaging brain was normal in all patients. Patients were followed up over 6 months to 8 years with no change in the final diagnosis. VM can rarely present as an acute peripheral vestibulopathy with findings that mimic vestibular neuritis and should be considered in the differential diagnosis of acute prolonged vertigo.

The Newly Normed SKT Reveals Differences in Neuropsychological Profiles of Patients with MCI, Mild Dementia and Depression

The SKT (Syndrom-Kurztest) is a short cognitive performance test assessing deficits of memory and attention in the sense of speed of information processing. The new standardization of the SKT (2015) aimed at improving its sensitivity for early cognitive decline due to dementia in subjects aged 60 or older. The goal of this article is to demonstrate how the neuropsychological test profile of the SKT can be used to provide valuable information for a differential diagnosis between MCI (mild cognitive impairment), dementia and depression. n = 549 patients attending a memory clinic (Nuremberg, Germany) were diagnosed according to ICD-10 and tested with the SKT. The SKT consists of nine subtests, three for the assessment of memory and six for measuring attention in the sense of speed of information processing. The result of the SKT test procedure is a total score, which indicates the severity of overall cognitive impairment. Besides the summary score, two subscores for memory and attention can be interpreted. Using the level of depression as a covariate, statistical comparisons of SKT test profiles between the three patient groups revealed that depressed patients showed more pronounced deficits than MCI patients in all six attention subtests. On the other hand, MCI patients displayed significantly greater mnestic impairment than the depressed group, which was indicated by significant differences in the memory subscore. MCI and dementia patients showed similar deficit patterns dominated by impairment of memory (delayed recall) with MCI patients demonstrating less overall impairment. In sum, the SKT neuropsychological test profiles provided indicators for a differential diagnosis between MCI and beginning dementia vs. depression.

A Study on the Reliability Test of a Lithium Battery in Medical Electric Wheelchairs for Vulnerable Drivers

There are test items for lithium-ion batteries in reliability testing for automobiles and motorcycles, but equivalent test items have not yet been established for mobility scooters (also known as electronic wheelchairs). To evaluate the lithium-ion battery pack or system mounted on a mobility scooter, it is necessary to test vibrations and mechanical shock while driving, independent of tests for the lithium-ion battery cells. In an effort to meet this need, test profiles were established for mobility scooter lithium-ion batteries by performing on-road driving tests and mechanical shock tests. The proposed test profiles were validated using robust statistics and proficiency statistics. The safety of the test profiles was tested in a nationally accredited testing laboratory. As a result, the lithium-ion battery mounted on the mobility scooter was found to have incurred no leakage, short circuit, burst, or explosion. The vibration and mechanical shock test profiles proposed in this study are expected to serve as basis data for establishing standards for mobility scooter safety and reliability.