A novel concept to evaluate desalination performance in capacitive deionization (CDI) is proposed called the CDI Ragone plot. The plot can allow for intuitive acquisition of deionization capacity (mg ...g −1 ), rate (mg g −1 s −1 ), and time (s) and thus, will work as a functional tool to evaluate desalination performance in CDI.
We propose an unsupervised video segmentation approach by simultaneously tracking multiple holistic figure-ground segments. Segment tracks are initialized from a pool of segment proposals generated ...from a figure-ground segmentation algorithm. Then, online non-local appearance models are trained incrementally for each track using a multi-output regularized least squares formulation. By using the same set of training examples for all segment tracks, a computational trick allows us to track hundreds of segment tracks efficiently, as well as perform optimal online updates in closed-form. Besides, a new composite statistical inference approach is proposed for refining the obtained segment tracks, which breaks down the initial segment proposals and recombines for better ones by utilizing high-order statistic estimates from the appearance model and enforcing temporal consistency. For evaluating the algorithm, a dataset, SegTrack v2, is collected with about 1,000 frames with pixel-level annotations. The proposed framework outperforms state-of-the-art approaches in the dataset, showing its efficiency and robustness to challenges in different video sequences.
Environment-related parameters, including viscosity, polarity, temperature, hypoxia, and pH, play pivotal roles in controlling the physical or chemical behaviors of local molecules. In particular, in ...a biological environment, such factors predominantly determine the biological properties of the local environment or reflect corresponding status alterations. Abnormal changes in these factors would cause cellular malfunction or become a hallmark of the occurrence of severe diseases. Therefore, in recent years, they have increasingly attracted research interest from the fields of chemistry and biological chemistry. With the emergence of fluorescence sensing and imaging technology, several fluorescent chemosensors have been designed to respond to such parameters and to further map their distributions and variations in vitro/in vivo. In this work, we have reviewed a number of various environment-responsive chemosensors related to fluorescent recognition of viscosity, polarity, temperature, hypoxia, and pH that have been reported thus far.
Here, we propose a CNN-based infrared image enhancement method to transform pseudo-realistic regions of simulation-based infrared images into real infrared texture. The proposed algorithm consists of ...the following three steps. First, target infrared features based on a real infrared image are extracted through pretrained VGG-19 networks. Next, by implementing a neural style-transfer algorithm to a simulated infrared image, fractal nature features from the real infrared image are progressively applied to the image. Therefore, the fractal characteristics of the simulated image are improved. Finally, based on the results of fractal analysis, peak signal-to-noise (PSNR), structural similarity index measure (SSIM), and natural image quality evaluator (NIQE) texture evaluations are performed to know how the simulated infrared image is properly transformed as it contains the real infrared fractal features. We verified the proposed methodology using a simulation with three different simulation conditions with a real mid-wave infrared (MWIR) image. As a result, the enhanced simulated infrared images based on the proposed algorithm have better NIQE and SSIM score values in both brightness and fractal characteristics, indicating the closest similarity to the given actual infrared image. The proposed image fractal feature analysis technique can be widely used not only for the simulated infrared images but also for general synthetic images.
The fabrication and design principles for using silver‐nanowire (AgNW) networks as transparent electrodes for flexible film heaters are described. For best practice, AgNWs are synthesized with a ...small diameter and network structures of the AgNW films are optimized, demonstrating a favorably low surface resistivity in transparent layouts with a high figure‐of‐merit value. To explore their potential in transparent electrodes, a transparent film heater is constructed based on uniformly interconnected AgNW networks, which yields an effective and rapid heating of the film at low input voltages. In addition, the AgNW‐based film heater is capable of accommodating a large amount of compressive or tensile strains in a completely reversible fashion, thereby yielding an excellent mechanical flexibility. The AgNW networks demonstrated here possess attractive features for both conventional and emerging applications of transparent flexible electrodes.
A scalable and facile method of preparing highly transparent and flexible electrodes for film heaters based on solution‐ processed silver‐nanowire (AgNW) networks is presented. By optimizing the network structure of AgNWs, highly transparent and conductive AgNW films are demonstrated, which can yield the effective and rapid heating of the film at low input voltages.
Point-of-care (POC) diagnostic technologies for early stage diagnosis and real-time monitoring of medical conditions are important element of healthcare strategy to improve medical treatment ...outcomes. Graphene, one-atom-thick fabric of carbon, has attracted enormous attention as a new sensing platform for the development of a new generation of nanoscale sensing devices. The two-dimensional (2D) nanostructure and high surface-to-volume ratio of graphene provide a strategy for designing sensing devices with capability to detect diverse analyte molecules. Their excellent conductivity and zero-band gap features promote electron transport between the sensor and analyte molecules, which is crucial for the development of ultra-fast-responsive and high sensitive devices for numerous biomedical applications. Particularly, owing to ease of fabrication and miniaturization, low cost, and simplicity of operation, graphene-based sensors offer a great potential for portable real-time medical diagnostics, when compared with conventional techniques based on expensive and labor extensive lab-bench instruments. This review provides a brief overview of recent progress in graphene-based sensors for the detection of volatile organic compounds (VOCs) and diagnosis of diseases via non-invasive analysis. Techniques for the fabrication of sensors and critical analysis of VOCs detection devices associated with various diseases are presented. We also summarized approaches to overcome the remaining obstacles in real-world applications of sensors in clinical diagnosis.
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Capacitive deionization (CDI) is an electrochemically controlled desalination technology based on applying a non-faradaic process in the electrical double layer region. Because CDI performance is ...affected by the type of operational mode, this study examined salt adsorption capacity (deionization capacity) and energy consumption of two CDI operational modes, constant voltage (CV) and constant current (CC). The use of higher cell voltage in CV mode resulted in faster salt adsorption under a given charging time due to stronger electrostatic attraction than CC mode. However, despite of the faster salt adsorption of CV mode, CC mode showed much lower energy consumption than CV mode by 26%–30% as an identical electrical charge was consumed or an identical amount of ion removal was considered. This lower energy consumption is due to the overall lower cell voltage used in CC mode than in CV mode. This study suggests that better salt adsorption capacity and energy consumption in CDI operation may be achieved by applying appropriate CV and CC modes.
•Constant voltage operation can achieve higher and faster desalination.•Constant current operation is more energy efficient per ion removed.•CV and CC operation is similar in charge efficiency.•Best CDI performance can be achieved by a combination of CV and CC operation.
Over the past decade, PV power plants have increasingly contributed to power generation. However, PV power generation widely varies due to environmental factors; thus, the accurate forecasting of PV ...generation becomes essential. Meanwhile, weather data for environmental factors include many missing values; for example, when we estimated the missing values in the precipitation data of the Korea Meteorological Agency, they amounted to ~16% from 2015–2016, and further, 19% of the weather data were missing for 2017. Such missing values deteriorate the PV power generation prediction performance, and they need to be eliminated by filling in other values. Here, we explore the impact of missing data imputation methods that can be used to replace these missing values. We apply four missing data imputation methods to the training data and test data of the prediction model based on support vector regression. When the k-nearest neighbors method is applied to the test data, the prediction performance yields results closest to those for the original data with no missing values, and the prediction model’s performance is stable even when the missing data rate increases. Therefore, we conclude that the most appropriate missing data imputation for application to PV forecasting is the KNN method.
Two-dimensional (2D) materials, such as molybdenum disulfide (MoS2) of the transition metal dichalcogenides family, are widely investigated because of their outstanding electrical and optical ...properties. However, not much of the 2D materials research completed to date has covered large-area structures comprised of high-quality heterojunction diodes. We fabricated a large-area n-MoS2/p-Si heterojunction structure by sulfurization of MoOx film, which is thermally evaporated on p-type silicon substrate. The n-MoS2/p-Si structure possessed excellent diode characteristics such as ideality factor of 1.53 and rectification ratio in excess of 104. Photoresponsivity and detectivity of the diode showed up to 475 mA/W and 6.5 × 1011 Jones, respectively, in wavelength ranges from visible to near-infrared. The device appeared also the maximum external quantum efficiency of 72%. The rise and decay times of optical transient response were measured about 19.78 ms and 0.99 ms, respectively. These results suggest that the sulfurization process for large-area 2D heterojunction with MoS2 can be applicable to next-generation electronic and optoelectronic devices.
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