Search

Emissions from wind turbines (WT) cover a wide range of infrasound and ground motions. When they are perceived as immissions by local residents, they can become a source of disturbance or annoyance. To mitigate such disturbances, it is necessary to better understand and, if possible, suppress WT-induced emissions. Within the project Inter-Wind we record and analyze ground motion signals in the vicinity of two wind farms on the Swabian Alb in southern Germany, simultaneously with acoustic and meteorological measurements, as well as psychological surveys done by cooperating research groups. The investigated wind farms consist of 3 and 16 WTs, respectively, and are located on the Alb peneplain at 700–800 m height, approximately 300 m higher than the two municipalities considered in our study. Our main aim is to better understand reasons why residents may be affected from WT immissions. Known ground motions include vibrations due to eigenmodes of the WT tower and blades, and the interaction between the passing blade and the tower, causing signals at constant frequencies below 12 Hz. In addition, we observe signals in ground motion recordings at frequencies up to 90 Hz which are proportional to the blade-passing frequency. We can correlate these signals with acoustic recordings and estimate sound pressure to ground motion coupling transfer coefficients of 3–16.5 µms-1Pa-1. Sources for these emissions are the WT generator and possibly the gearing box. The identification of such noise sources can help to find measures to reduce disturbances in order to increase the public acceptance of WTs. Residents perceive more disturbance at the location where the wind farm is closer to the municipality (approximately 1 km). However, there is also a major railway line which produces higher vibration and infrasound signal amplitudes compared to the WTs. Along the measurement lines the decay rate of the WT-induced ground motions is determined for a damping relation proportional to 1/rb. We find frequency-dependent b values for different scenarios at our geological setting of Jurassic limestone on marl, sandstone, and Quaternary deposits. These damping relationships can be used to estimate emissions in the far field and to plan mitigation strategies.

Purpose: Global efforts to combat the COVID-19 pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have placed renewed focus on the use of transmission electron microscopy (EM) for infectious disease diagnosis and detection. Recently, attempts to identify SARS-CoV-2 directly in human autopsy and animal necropsy tissues have inaccurately identified normal subcellular structures, including coated vesicles, multivesicular bodies, and rough endoplasmic reticulum, as coronavirus particles. Working with SARS-CoV-2 positive autopsy and necropsy tissues, the Infectious Diseases Pathology Branch at CDC sought to use EM to accurately detect coronavirus particles. Methods & Materials: Two sample types were used, formalin-fixed wet tissue and formalin-fixed paraffin embedded (FFPE) tissue blocks. Wet tissue samples provide the best preservation of ultrastructure but require a time-intensive search for viral particles. FFPE tissues enable a targeted approach to finding viral particles but with deteriorated ultrastructure. Areas of formalin-fixed wet tissue showing evident disease pathology were selected for EM, while areas of interest from FFPE blocks were selected based on results from SARS-CoV-2 immunohistochemistry and in situ hybridization results. All samples were post-fixed with 1% osmium tetroxide, en-bloc stained with uranyl acetate, dehydrated, and embedded in Epon-Araldite resin. Results: A multifaceted approach for SARS-CoV-2 detection in autopsy and necropsy tissues allowed for swift and accurate determination of the localization of coronavirus and correlation of histopathological and ultrastructural features of SARS-CoV-2 infection. Coronavirus particles were found associated with degenerating cells in the alveolar space, in pneumocytes, and near collagen of the heart in fetal tissue as well as in the syncytiotrophoblast of the placenta. In animal tissues, virus was found in the bronchiolar epithelium and type 1 pneumocytes. Conclusion: Comprehensive studies of SARS-CoV-2 infection, and all emerging pathogens, are crucial to improving the understanding of pathogenesis and for the formulation of clinical treatments and transmission prevention measures. An important part of this process is providing robust EM evidence of SARS-CoV-2 localization within tissues to ensure that misinterpretations of subcellular structures as virus are reduced, enabling more accurate conclusions concerning COVID-19 pathology and disease.

In the context of the Industry 4.0 initiative, Cyber-Physical Production Systems (CPPS) or Cyber Manufacturing Systems (CMS) can be characterized as advanced networked mechatronic production systems gaining their added value by interaction with the ambient Industrial Internet of Things (IIoT). In this context appropriate communication technologies and standards play a vital role to realize the manifold potential improvements in the production process. One of these standards is IO-Link. In 2016 more than 5 million IO-Link nodes have been produced and delivered, still gaining increasing acceptance for the communication between sensors, actuators and the control level. The steadily increasing demand for more flexibility in automation solutions can be fulfilled using wireless technologies. With the wireless extension for the IO-Link standard, which will be presented in this article, maximum cycle times of 5 ms can be achieved with a probability that this limit will be exceeded to be at maximum one part per billion. Also roaming capabilities, wireless coexistence mechanisms and the possibility to include battery-powered or energy-harvesting sensors with very limited energy resources in the realtime network were defined. For system planning, setup, operation and maintenance, the standard engineering tools of IO-Link can be employed so that the backward compatibility with wired IO-Link solutions can be guaranteed. Interoperability between manufacturers is a key requirement for any communication standard, thus a procedure for IO-Link Wireless testing is also suggested.

In civil and military aviation, ground based navigation aids (NAVAIDS) are still crucial for flight guidance even though the acceptance of satellite based systems (GNSS) increases. Part of the calibration process for NAVAIDS (ILS, DME, VOR) is to perform a flight inspection according to specified methods as stated in a document (DOC8071, 2000) by the International Civil Aviation Organization (ICAO). One major task is to determine the coverage, or, in other words, the true signal-in-space field strength of a ground transmitter. This has always been a challenge to flight inspection up to now, since, especially in the L-band (DME, 1GHz), the antenna installed performance was known with an uncertainty of 10 dB or even more. In order to meet ICAO's required accuracy of ±3 dB it is necessary to have a precise 3-D antenna factor of the receiving antenna operating on the airborne platform including all losses and impedance mismatching. Introducing precise, effective antenna factors to flight inspection to achieve the required accuracy is new and not published in relevant papers yet. The authors try to establish a new balanced procedure between simulation and validation by airborne and ground measurements. This involves the interpretation of measured scattering parameters gained both on the ground and airborne in comparison with numerical results obtained by the multilevel fast multipole algorithm (MLFMA) accelerated method of moments (MoM) using a complex geometric model of the aircraft. First results will be presented in this paper.

Understanding factors that influence a species' distribution and abundance across the annual cycle is required for range-wide conservation. Thousands of imperiled red knots (Calidris cantus rufa) stop on Virginia's barrier islands each year to replenish fat during spring migration. We investigated the variation in red knot presence and flock size, the effects of prey on this variation, and factors influencing prey abundance on Virginia's barrier islands. We counted red knots and collected potential prey samples at randomly selected sites from 2007-2018 during a two-week period during early and peak migration. Core samples contained crustaceans (Orders Amphipoda and Calanoida), blue mussels (Mytilus edulis), coquina clams (Donax variabilis), and miscellaneous prey (horseshoe crab eggs (Limulus polyphemus), angel wing clams (Cyrtopleura costata), and other organisms (e.g., insect larvae, snails, worms)). Estimated red knot peak counts in Virginia during 21-27 May were highest in 2012 (11,959) and lowest in 2014 (2,857; 12-year peak migration [Formula: see text] = 7,175, SD = 2,869). Red knot and prey numbers varied across sampling periods and substrates (i.e., peat and sand). Red knots generally used sites with more prey. Miscellaneous prey ([Formula: see text] = 2401.00/m2, SE = 169.16) influenced red knot presence at a site early in migration, when we only sampled on peat banks. Coquina clams ([Formula: see text] = 1383.54/m2, SE = 125.32) and blue mussels ([Formula: see text] = 777.91/m2, SE = 259.31) affected red knot presence at a site during peak migration, when we sampled both substrates. Few relationships between prey and red knot flock size existed, suggesting that other unmeasured factors determined red knot numbers at occupied sites. Tide and mean daily water temperature affected prey abundance. Maximizing the diversity, availability, and abundance of prey for red knots on barrier islands requires management that encourages the presence of both sand and peat bank intertidal habitats.