Reverse Scan Conversion and Efficient Deep Learning Network Architecture for Ultrasound Imaging on a Mobile Device

Point-of-care ultrasound (POCUS), realized by recent developments in portable ultrasound imaging systems for prompt diagnosis and treatment, has become a major tool in accidents or emergencies. Concomitantly, the number of untrained/unskilled staff not familiar with the operation of the ultrasound system for diagnosis is increasing. By providing an imaging guide to assist clinical decisions and support diagnosis, the risk brought by inexperienced users can be managed. Recently, deep learning has been employed to guide users in ultrasound scanning and diagnosis. However, in a cloud-based ultrasonic artificial intelligence system, the use of POCUS is limited due to information security, network integrity, and significant energy consumption. To address this, we propose (1) a structure that simultaneously provides ultrasound imaging and a mobile device-based ultrasound image guide using deep learning, and (2) a reverse scan conversion (RSC) method for building an ultrasound training dataset to increase the accuracy of the deep learning model. Experimental results show that the proposed structure can achieve ultrasound imaging and deep learning simultaneously at a maximum rate of 42.9 frames per second, and that the RSC method improves the image classification accuracy by more than 3%.

The Influence of External Load on the Performance of Microbial Fuel Cells

In this work, the effect of the external load on the current and power generation, as well as on the pollutant removal by microbial fuel cells (MFCs), has been studied by step-wise modifying the external load. The load changes included a direct scan, in which the external resistance was increased from 120 Ω to 3300 Ω, and a subsequent reverse scan, in which the external resistance was decreased back to 120 Ω. The reduction in the current, experienced when increasing the external resistance, was maintained even in the reverse scan when the external resistance was step-wise decreased. Regarding the power exerted, when the external resistance was increased below the value of the internal resistance, an enhancement in the power exerted was observed. However, when operating near the value of the internal resistance, a stable power exerted of about 1.6 µW was reached. These current and power responses can be explained by the change in population distribution, which shifts to a more fermentative than electrogenic culture, as was confirmed by the population analyses. Regarding the pollutant removal, the effluent chemical oxygen demand (COD) decreased when the external resistance increased up to the internal resistance value. However, the effluent COD increased when the external resistance was higher than the internal resistance. This behavior was maintained in the reverse scan, which confirmed the modification in the microbial population of the MFC.

Quantification of 4-Nitrophenol on Nanosize Polyaniline Modified Glassy Carbon Electrode through Electrochemical Method

The electrochemical studies of 4-nitrophenol were carried out in acidic, neutral and basic buffer media at bare glassy carbon (GC) and nanosize polyaniline (PANI) modified GC electrodes. In all pH, 4-nitrophenol exhibits three oxidation peaks in forward scan and three reduction peaks in reverse scan in the CV. The peak current reached its maximum value at pH 7.0. The effect of scan rate was studied between 25 and 500 mVs-1 at pH 7. CV results revealed the diffusion-controlled reaction at the electrode surface. The atomic force microscopy used for studies of morphological behavior of nanosize polyaniline and compound adsorbed on PANI surface. Under optimum DPSV experimental conditions, the influence of concentration on the stripping signal was studied A linear relationship between peak current and concentration is obtained in the range 100 to 500 ppb, with lower detection limit of 50 ppb on PANI/GCE. The relative standard deviation of 1.76% for a 250ppb 4-nitrophenol concentration and relative error of 2.6% were also obtained.

Carbon nanotube modified glassy carbon electrode for electrochemical oxidation of alkylphenol ethoxylate

Electrochemical oxidation of an emerging pollutant, 2-(4-methylphenoxy)ethanol (MPET), from water has been studied by cyclic voltammetry (CV). Multiwall carbon nanotubes glassy carbon electrodes (MWCNT-GCE) were used as working electrode due to their extraordinary properties. The oxidation process is irreversible, since no reduction peaks were observed in the reverse scan. The electrocatalytic effect of MWCNT was confirmed as the oxidation peak intensity increases in comparison to bare-GCE. The effect of functional groups on MWCNT was also studied by MWCNT functionalized with NH2 (MWCNT-NH2) and COOH (MWCNT-COOH) groups. The oxidation peak current decreases in the following order: MWCNT > MWCNT-NH2 > MWCNT-COOH. Taking into account the normalized peak current, MWCNT-NH2 exhibits the best results due to its strong interaction with MPET. Under optimal conditions (pH = 5.0 and volume of MWCNT = 10 μL), degradation was studied for MWCNT-GCE and MWCNT-NH2-GCE. A complete MPET removal was observed using MWCNT-GCE after four CV cycles, for a volume/area (V/A) ratio equal to 19. In the case of MWCNT-NH2-GCE, the maximum MPET removal was close to 90% for V/A = 37, higher than that obtained for MWCNT-GCE at the same conditions (≈80%). In both cases, no organic by-products were detected.

Enhanced performance via partial lead replacement with calcium for a CsPbI3 perovskite solar cell exceeding 13% power conversion efficiency

Partial replacement of Pb in CsPbI3 perovskite solar cells with Ca enhances power conversion efficiency to 13.5% under reverse scan (stabilised at 13.3%), without sacrificing stability.

Effect of Modulating Spin-Coating Rate of TiO2Precursor for Mesoporous Layer onJ-VHysteresis of Solar Cells with Polar CH3NH3PbI3Perovskite Thin Film

Compared with the crystalline Si solar cells, theJ-Vcharacteristics of CH3NH3PbI3perovskite solar cells are different under forward and reverse scan, and the CH3NH3PbI3film exhibits some polarization properties. To explore those performances of the mesoporous TiO2layer based perovskite solar cells, we focus on the effect of modulating the spin-coating rate of the TiO2precursor for mesoporous layer onJ-Vhysteresis of solar cells with the polar film byJ-Vcurves, atomic force microscopy topographic images, and piezoresponse force microscopy phase images. Firstly, the AFM images illustrate that the polarization behaviors exist and the deformation scale is large at the corresponding position when the DC bias voltage increases. Secondly, it is suggested that the polar films which applied the positive DC biases voltage show a tendency to 0° phase angle, while the polar films which applied the negative DC biases voltage show a tendency to −180° phase angle. Thirdly, a weak polar hysteresis loop relation for CH3NH3PbI3film was observed. Finally, the hysteresis index for the 1500 rpm mesostructured solar cell shows relatively lowJ-Vhysteresis compared with the 3000 rpm mesostructured and the planar-structured solar cell. Our experimental results bring novel routes for reducing the hysteresis and investigating the polar nature for CH3NH3PbI3material.

Highly efficient low temperature solution processable planar type CH3NH3PbI3 perovskite flexible solar cells

A highly efficient PEN/ITO/ZnO/CH3NH3PbI3 perovskite/PTAA/Au flexible planar solar cell with 1.1 V Voc, 18.7 mA cm−2Jsc, 75% FF, and 15.4% η for the forward scan direction and 1.1 V Voc, 18.7 mA cm−2Jsc, 76% FF and 15.6% η for the reverse scan direction under illumination of 1 Sun was demonstrated.

Zinc oxide as a hole blocking layer for perovskite solar cells deposited in atmospheric conditions

A sputtered ZnO thin film was used as electron extraction layer, in a planar perovskite based solar cell. As a result a maximum power conversion efficiency (PCE) of 14.2%, measured at reverse scan, has been demonstrated.