The challenge of a deep-water oil leak is that a significant quantity of oil remains in the water column and possibly changes properties. There is a need to quantify the oil settled within the water column and determine its physical properties to assist in the oil recovery. There are currently no methods to map acoustically submerged oil in the sea. In this paper, high-frequency acoustic methods are proposed to localize the oil polluted area and characterize the parameters of its spatial covariance, i.e., variance and correlation. A model is implemented to study the underlying mechanisms of backscattering due to spatial heterogeneity of the medium and predict backscattering returns. An algorithm for synthetically generating stationary, Gaussian random fields is introduced which provides great flexibility in implementing the physical model of an inhomogeneous field with spatial covariance. A method for inference of spatial covariance parameters is proposed to describe the scattering field in terms of its second-order statistics from the backscattered returns. The results indicate that high-frequency acoustic methods not only are suitable for large-scale detection of oil contamination in the water column but also allow inference of the spatial covariance parameters resulting in a statistical description of the oil field.
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http://dx.doi.org/10.1121/1.4818897 | DOI Listing |
CNS Neurosci Ther
January 2025
Department of Otolaryngology, Nanjing First Hospital, Nanjing Medical University, Nanjing, China.
Background: Sudden sensorineural hearing loss (SSNHL) is associated with abnormal changes in the brain's central nervous system. Previous studies on the brain networks of SSNHL have primarily focused on functional connectivity within the brain. However, in addition to functional connectivity, structural connectivity also plays a crucial role in brain networks.
View Article and Find Full Text PDFIn image-guided radiotherapy (IGRT), four-dimensional cone-beam computed tomography (4D-CBCT) is critical for assessing tumor motion during a patients breathing cycle prior to beam delivery. However, generating 4D-CBCT images with sufficient quality requires significantly more projection images than a standard 3D-CBCT scan, leading to extended scanning times and increased imaging dose to the patient. To address these limitations, there is a strong demand for methods capable of reconstructing high-quality 4D-CBCT images from a 1-minute 3D-CBCT acquisition.
View Article and Find Full Text PDFJ Prev Alzheimers Dis
February 2025
Department of Neurology, Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin, China, 154 Anshan Road Tianjin 300052, PR China; Department of Neurology, Tianjin Medical University General Hospital Airport Site, Tianjin 300052, PR China. Electronic address:
Background: Changes in cerebral blood flow (CBF) may contribute to the initial stages of the pathophysiological process in patients with Alzheimer's disease (AD). Hypoperfusion has been observed in several brain regions in patients with mild cognitive impairment (MCI). However, the clinical significance of CBF changes in the early stages of AD is currently unclear.
View Article and Find Full Text PDFAnimals (Basel)
January 2025
College of Veterinary Medicine, Chungbuk National University, Cheongju 28644, Chungbuk, Republic of Korea.
Snakebites are a significant global health concern; despite various known risk factors, the role of environmental changes, such as deforestation, remains underexplored. Therefore, we investigated the association between deforestation and snakebite incidence in South Korea. Aggregated data were obtained from the National Health Insurance Service (NHIS) and the National Emergency Department Information System (NEDIS) from 2014 to 2021.
View Article and Find Full Text PDFSci Rep
January 2025
Department of Oral and Maxillofacial Surgery, Gangnam Severance Hospital, Yonsei University College of Dentistry, 211 Eonju-ro, Gangnam-gu, Seoul, 06273, Korea.
This retrospective study aimed to evaluate the difference in the temporomandibular joint (TMJ) space volume between the deviated (Dev) and non-deviated (NDev) side following transoral vertical ramus osteotomy (TOVRO) in patients with mandibular prognathism combined with asymmetry using reconstructed 3-dimensional images. Sixty joints from 30 patients who underwent TOVRO between January 2018 and December 2021 were included. Computed tomography (CT) or cone-beam CT was performed before surgery (T0), and 6 (T1) and 12 months postoperatively (T2).
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