Considerations on Acoustic Mapping Velocimetry (AMV) Application for in-situ Measurement of Bedform Dynamics

Non-intrusive technologies for the in-situ measurement of river morphological features are increasingly popular in the scientific and practice communities due to their efficient and productive data acquisition. While the measurement of suspended load with optical and acoustic technologies is currently an active area of research, the measurement of bedform dynamics has not experienced similar progress. We have successfully demonstrated through laboratory experiments that, by combining acoustic mapping with image velocimetry concepts, we can characterize the planar dynamics of the bedform migration. The technique, labeled Acoustic Mapping Velocimetry (AMV), is currently transferred to field conditions using multiple-beam echo-sounders (MBES) for producing acoustic maps. During this transfer, new questions emerged because, in field conditions, many of the morphologic features targeted by AMV measurements are not a priori known. Moreover, the image velocimetry processing can be approached with several alternatives, each of them characterized by strength and limitations. This paper assembles guidelines for establishing optimal parameters for the acquisition of the acoustic maps based on analytical considerations, and for selecting essential features of the processing for image velocimetry. We test these guidelines using MBES data acquired in the Mississippi River.

Bayesian Multidimensional Scaling for Location Awareness in Hybrid-Internet of Underwater Things

<div> <div> <div> <p>Localization of sensor nodes in the Internet of Underwater Things (IoUT) is of considerable significance due to its various applications, such as navigation, data tagging, and detection of underwater objects. Therefore, in this paper, we propose a hybrid Bayesian multidimensional scaling (BMDS) based localization technique that can work on a fully hybrid IoUT network where the nodes can communicate using either optical, magnetic induction, and acoustic technologies. These communication technologies are already used for communication in the underwater environment; however, lacking localization solutions. Optical and magnetic induction communication achieves higher data rates for short communication. On the contrary, acoustic waves provide a low data rate for long-range underwater communication. The proposed method collectively uses optical, magnetic induction, and acoustic communication-based ranging to estimate the underwater sensor nodes’ final locations. Moreover, we also analyze the proposed scheme by deriving the hybrid Cramer-Rao lower bound (H-CRLB). Simulation results provide a complete comparative analysis of the proposed method with the literature. </p> </div> </div> </div>

Bayesian Multidimensional Scaling for Location Awareness in Hybrid-Internet of Underwater Things

<div> <div> <div> <p>Localization of sensor nodes in the Internet of Underwater Things (IoUT) is of considerable significance due to its various applications, such as navigation, data tagging, and detection of underwater objects. Therefore, in this paper, we propose a hybrid Bayesian multidimensional scaling (BMDS) based localization technique that can work on a fully hybrid IoUT network where the nodes can communicate using either optical, magnetic induction, and acoustic technologies. These communication technologies are already used for communication in the underwater environment; however, lacking localization solutions. Optical and magnetic induction communication achieves higher data rates for short communication. On the contrary, acoustic waves provide a low data rate for long-range underwater communication. The proposed method collectively uses optical, magnetic induction, and acoustic communication-based ranging to estimate the underwater sensor nodes’ final locations. Moreover, we also analyze the proposed scheme by deriving the hybrid Cramer-Rao lower bound (H-CRLB). Simulation results provide a complete comparative analysis of the proposed method with the literature. </p> </div> </div> </div>

Electromagnetic and acoustic technologies in antibacterial preparation development

Subject and Purpose. The present paper is concerned with the use of wave technologies in the development of antibiotics-alternative approaches for pathogenic microflora suppression. Lactobacilli strains picked in different ecological niches and their activity against pathogenic strains are studied with a focus on a targeted modification of adhesive and antagonistic properties of lactobacilli by exposing them to low-intensity electromagnetic (EM) fields and the ultrasound. Methods and Methodology. Lactobacilli picked in different ecological niches are experimentally studied, including (1) standard strains from probiotic preparations and (2) circulating strains picked in humans and bees. For the ultrasonic and electromagnetic radiation sources, G3-109 and G3-F and G4-141 and G4-142 generators are taken, respectively. The adhesive properties of Lactobacillus spp. strains and their antagonistic activity are estimated against C. diphtheriae, S. aureus and yeast-like fungi of Candida genus in aerobic and microaerophilic culture conditions. Statistical technology is employed in the data processing and analysis. Results. It has been established that L. plantarum strains picked in the gut of healthy bees are most antagonistic towards pathogens. It has been demonstrated that the priority culture conditions for lactobacilli are microaerophilic conditions simulating their stay in vivo. It has been shown that it is possible to modify properties of microorganisms by their exposure to ultrasound and low-intensity electromagnetic fields in narrow bands of the EHF range. The effect efficiency versus frequency has a dispersion character. Individual features of various pathogenic strains have been recognized. Conclusion. The obtained results open up prospects for electromagnetic and acoustic technologies in the development of safe alternative means to antagonize persisting pathogens and increase human body resilience.

Magnetometry, Acoustical and Inertial Indoor-Positioning in Healthcare

Introduction. The problem of localization of moving objects inside buildings becomes more urgent in healthcare. Tracking the movements of patients in real time allows one to provide them with timely medical support in case of sharp deterioration in their vital signs. It is especially important to track the location of patients undergoing a surgery, since the risk of death due to postoperative complications for them is extremely high. Using indoor-positioning technologies in telemedicine systems can solve the problem, thereby reducing the mortality rate of patients and improving the quality of medical care.Aim. To study the applicability of magnetometry, inertial and acoustic technologies for patient’s localization in a hospital.Materials and methods. The analysis of domestic and foreign scientific sources devoted to indoor-positioning based on the above technologies was carried out. Material published not earlier than 2016, was chosen for the analysis. Most of the papers were published in journals with impact-factor not lower than 3.Results. After analyzing the information received, it was concluded that none of the technologies can be used independently. Inertial sensors possess high accuracy, but over time, the measurement error increases. There-fore, the sensors need to regular correction. Indoor-positioning based on geomagnetism is hampered by interference that can be induced by the operation of magnetic resonance imaging scanners and X-ray equipment, which are usually used in medical facilities. Active magnetometry does not allow to keep track of moving objects due to specific of hardware used. Ultrasound-based positioning can be complicated by ultrasonography apparatuses interference. Using an audible sound creates noise pollution and exerts a negative impact on patient’s health. Also, acoustic technologies are unable to provide a secure communication channel for data exchange.Conclusion. It is recommended to combine the reviewed positioning technologies with other technologies in order to correct the indicated disadvantages.

Applying Two Active Acoustic Technologies to Document Presence of Large Marine Animal Targets at a Marine Renewable Energy Site

Coastal regions are highly used by humans. The growing marine renewable energy (MRE) industry will add to existing anthropogenic pressures in these regions. Regulatory bodies require animal risk assessment before new industrial activities can progress, and MRE is no exception. Preliminary data of marine mammal use of an MRE device deployment location could be informative to permitting. A combination of downlooking hydroacoustics using an echosounder and acoustic camera (imaging sonar) was used to provide a number of large targets (proxy for large fish and marine mammals) in an area of interest for MRE tidal turbine deployment in Western Passage, Maine, USA. Data were collected in May, June, August, and September of 2010 and 2011. Of the nine large targets confirmed to be animals, eight were porpoises and one was a shark. Few large targets were observed in May and June, with the majority (90%) being present in August and September of both years. The most large targets were observed when tidal current speed was less than 1 m·s−1. These data provide a preliminary assessment of large targets in a single location over sixteen 24-h surveys. The aforementioned methodology could be used for future pre- and post-installation assessments at MRE device deployment locations. Their use in concert with visual and passive acoustic monitoring can provide water depth usage by marine mammals, which is a metric that is difficult to assess with passive acoustic and visual techniques.

Hydro-acoustic Survey and Edge-detection method in Investigation of a Passenger Vessel Accident in East Java, Indonesia

As an archipelagic country, the shipping sector in Indonesia becomes crucial in delivering goods inter-island, and due to increasing transportation demands. However, that industry encounters some challenges of the ocean environment that could lead to vessel accidents. An investigation into the accident is crucial since this is related to the properties, environment, and life disadvantages. The wrecks of sinking vessels also could harm the environment, providing an obstacle to the sea passage hence increasing the risk of a shipping operation. A proper and comprehensive investigation needs to be carried out to identify the factors that contribute to the accident, so then risk mitigation can be taken to prevent re-occurrence. In the case of missing foundered or sunken vessels, an underwater examination is a must, so the investigator understands the real condition of the vessel. Although diver and underwater robotic surveys are still prevalent in the investigation, these techniques have limitations due to visibility and location. By contrast, those limitations can be addressed using hydro-acoustic technologies, which are capable of providing high-resolution underwater images and digital elevation model (DEM) bathymetry. Thus, the use of these technologies is promising in-vessel accident investigation, both in-situ investigation, and post-processing analysis. This paper describes an examination of the use of side-scan sonar and multibeam echosounder in-vessel accident investigation. The use of slope feature and edge-detection technique are also investigated concerning the investigation. Results indicate that those acoustic systems can contribute to the inquiry effectively by portraying some underwater objects as the accident suspects. Besides, slope and edge detection methods also produce expectant outcomes to support underwater object detection and investigation.

Altering the Course of Technologies to Monitor Loosening States of Endoprosthetic Implants

Musculoskeletal disorders are becoming an ever-growing societal burden and, as a result, millions of bone replacements surgeries are performed per year worldwide. Despite total joint replacements being recognized among the most successful surgeries of the last century, implant failure rates exceeding 10% are still reported. These numbers highlight the necessity of technologies to provide an accurate monitoring of the bone–implant interface state. This study provides a detailed review of the most relevant methodologies and technologies already proposed to monitor the loosening states of endoprosthetic implants, as well as their performance and experimental validation. A total of forty-two papers describing both intracorporeal and extracorporeal technologies for cemented or cementless fixation were thoroughly analyzed. Thirty-eight technologies were identified, which are categorized into five methodologies: vibrometric, acoustic, bioelectric impedance, magnetic induction, and strain. Research efforts were mainly focused on vibrometric and acoustic technologies. Differently, approaches based on bioelectric impedance, magnetic induction and strain have been less explored. Although most technologies are noninvasive and are able to monitor different loosening stages of endoprosthetic implants, they are not able to provide effective monitoring during daily living of patients.