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Measuring oil concentration in the aquatic environment is essential for determining the potential exposure, risk, or injury for oil spill response and natural resource damage assessment. Conventional analytical chemistry methods require samples to be collected in the field, shipped, and processed in the laboratory, which is also rather time-consuming, laborious, and costly. For rapid field response immediately after a spill, there is a need to estimate oil concentration in near real time. To make the oil analysis more portable, fast, and cost effective, we developed a plug-and-play device and a deep learning model to assess oil levels in water using fluorescent images of water samples. We constructed a 3D-printed device to collect fluorescent images of solvent-extracted water samples using an iPhone. We prepared approximately 1,300 samples of oil at different concentrations to train and test the deep learning model. The model comprises a convolutional neural network and a novel module of histogram bottleneck block with an attention mechanism to exploit the spectral features found in low-contrast images. This model predicts the oil concentration in weight per volume based on fluorescence image. We devised a confidence interval estimator by combining gradient boosting and polymodal regressor to provide a confidence assessment of our results. Our model achieved sufficient accuracy to predict oil levels for most environmental applications. We plan to improve the device and iPhone application as a near-real-time tool for oil spill responders to measure oil in water. [ABSTRACT FROM AUTHOR]

RDX/Al/wax explosives (RDX = cyclotrimethylenetrinitramine; (O2NNCH2)3) were studied in experiments designed to elucidate the effects of Al content and the surrounding medium on the energy output of aluminized explosives. Explosives with Al contents of 0%, 15%, and 30% were compared in water and concrete media. Results indicate that the explosive's bubble energy in water is higher (by 66%–90%) than the expansion energy in concrete. Heat, sound, and other energies in water (0.28–0.84 MJ kg–1) were much lower than that in concrete (1.49–2.81 MJ kg–1). For shock wave energy, the different media have much less impact on shock wave energy, with that in water being only 0.7%–7% higher than in concrete. The test data presented in this paper improve our understanding of how Al and the surrounding medium contribute to the energy output of the explosive, which is of great significance for improving the energy utilization efficiency of aluminized explosives in water and concrete. [ABSTRACT FROM AUTHOR]

OBJECTIVE: In order to solve the problem of image real-time processing and correction for high-speed endoscopic sweptsource optical coherence tomography (SS-OCT), we highly optimize a computer-unified device architecture-based platform and use a field-programmable gate array to summarize the application experience. MATERIALS AND METHODS: We use the Half-Sync/Half-Asyn mode to optimize memory in order to build a high-throughput data thread pool for CPU. We use asynchronous streaming architecture to multiplex multiple threads at high speed to accelerate data processing. At the same time, we design a rotary scanning position information encoding feedback module to suppress image drift, which can realize 25ns logic-timing sequence synchronization control through FPGA 40MHz clock. RESULTS: The maximum complete attainable axial-scan-processing rate (including memory transfer and display of B-scan frames) is 3.52 MHz for a 16-bit pixel depth and A-scans/s of 1024 pixels. To our knowledge, this is the fastest processing rate reported to date with a single-chip graphical processing unit for SS-OCT. Finally, the established high-speed SS-OCT is used to image mouse esophagus and human fingers, and the output images are stable. When the image size is 1024 × 1024 pixels, the real-time imaging rate is 200 frames per second. CONCLUSIONS: This paper develops a real-time image processing and reconstruction technology suitable for high-throughput SS-OCT systems, which can have high-density operation and efficient parallelism, while suppressing highspeed image drift. It lays the foundation for the non-destructive, in vivo, non-staining, fast and convenient early tumor diagnosis of high-speed endoscopic SS-OCT. [ABSTRACT FROM AUTHOR]

To better understand the influence of the aluminum content on the performance of aluminized explosives, experiments in concrete and cylinder tests were performed. Three types of RDX-based aluminized explosives, in which the mass ratio of aluminum content was 0%, 15%, and 30% were considered in this paper. The shock wave pressures of the aluminized explosives in the affected concrete bodies were measured using manganin pressure sensors. The acceleration ability was obtained using a high-speed camera and a rotating mirror streak camera. The peak pressure attenuation characteristics of the explosives with various aluminum contents indicated that a higher aluminum content is associated with a slower peak pressure attenuation of the shock wave. In addition, the results of the cylinder tests and the metal-rod acceleration tests revealed the influence of the aluminum content on the acceleration ability of explosives in three different time periods. The test data presented in this paper verified the relationship between the aluminum content and explosive performance, which is of great significance for optimizing the properties of aluminized explosives. [ABSTRACT FROM AUTHOR]

Liu and collaborators recently proposed an elliptical accretion disk model for tidal disruption events (TDEs). They showed that the accretion disks of optical/UV TDEs are large and highly eccentric and suggested that the broad optical emission lines with complex and diverse profiles originate in a cool eccentric accretion disk of random inclination and orientation. In this paper, we calculate the radiation efficiency of the elliptical accretion disk and investigate the implications for observations of TDEs. We compile observational data for the peak bolometric luminosity and total radiation energy after peak brightness of 18 TDE sources and compare these data to the predictions from the elliptical accretion disk model. Our results show that the observations are consistent with the theoretical predictions and that the majority of the orbital energy of the stellar debris is advected into the black hole (BH) without being converted into radiation. Furthermore, we derive the masses of the disrupted stars and the masses of the BHs of the TDEs. The BH masses obtained in this paper are also consistent with those calculated with the MBH–σ* relation. Our results provide an effective method for measuring the masses of BHs in large numbers of TDEs to be discovered in ongoing and next-generation sky surveys, regardless of whether the BHs are located at the centers of galactic nuclei or wander in disks and halos. [ABSTRACT FROM AUTHOR]