DART: Fast and Efficient Distributed Stream Processing Framework for Internet of Things

With the advent of the Internet‐of‐Things paradigm, the amount of data production has grown exponentially and the user demand for responsive consumption of data has increased significantly. Herein, we present DART, a fast and lightweight stream processing framework for the IoT environment. Because the DART framework targets a geospatially distributed environment of heterogeneous devices, the framework provides (1) an end‐user tool for device registration and application authoring, (2) automatic worker node monitoring and task allocations, and (3) runtime management of user applications with fault tolerance. To maximize performance, the DART framework adopts an actor model in which applications are segmented into microtasks and assigned to an actor following a single responsibility. To prove the feasibility of the proposed framework, we implemented the DART system. We also conducted experiments to show that the system can significantly reduce computing burdens and alleviate network load by utilizing the idle resources of intermediate edge devices.     

Ultrathin Sticker‐Type ZnO Thin Film Transistors Formed by Transfer Printing via Topological Confinement of Water‐Soluble Sacrificial Polymer in Dimple Structure

To create ultrathin sticker‐type electronic devices that can be attached to unconventional substrates, it is highly desirable to develop printable membrane‐type electronics on a handling substrate and then transfer the printing to a target surface. A facile method is presented for high‐efficiency transfer printing by controlling the interfacial adhesion between a handling substrate and an ultrathin substrate in a systematic manner under mild conditions. A water‐soluble sacrificial polymer layer is employed on a dimpled handling substrate, which enables the topological confinement of the polymer residue inside and near the dimples during the etching and drying processes to reduce the interfacial adhesion gently, creating a high yield of transfer printing in a deterministic manner. As an example of an electronic device that was created using this method, a highly flexible sticker‐type ZnO thin film transistor was successfully developed with a thickness of 13 μm including a printable ultrathin substrate, which can be attached to various substrates, such as paper, plastic, and stickers.     

Energy-efficient and fault-tolerant drone-BS placement in heterogeneous wireless sensor networks

Wireless Networks - This paper introduces a distributed and energy-aware algorithm, called Minimum Drone Placement (MDP) algorithm, to determine the minimum number of base stations mounted on...     

Novel Maskless Bumping for 3D Integration

A novel, maskless, low‐volume bumping material, called solder bump maker, which is composed of a resin and low‐melting‐point solder powder, has been developed. The resin features no distinct chemical reactions preventing the rheological coalescence of the solder, a deoxidation of the oxide layer on the solder powder for wetting on the pad at the solder melting point, and no major weight loss caused by out‐gassing. With these characteristics, the solder was successfully wetted onto a metal pad and formed a uniform solder bump array with pitches of 120 µm and 150 µm.     

Dye removal by almond shell residues: Studies on biosorption performance and process design

The objective of this research paper is to assess the biosorption potential of almond shell residues for methyl orange dye. The pseudo-second-order kinetic model described the dye biosorption process with a good fitting. The relationship between the pseudo-second-order model constants and the biosorption performance was also evaluated. The equilibrium data fit well with the Langmuir isotherm model presenting that the biosorption was the monolayer coverage of dye on the biosorbent and the homogeneity of active sites for dye binding on the biosorbent surface. Based on the Langmuir model, a single-stage batch biosorber was also designed to predict the biosorbent mass for certain percentage dye removal. Besides, the standard Gibbs free energy change was also calculated to define the nature of biosorption process. These results revealed that the utilization of almond shell residues as dye biosorbent could be an interesting option from both environmental and economic point of view.     

Strength and Frictional Properties of Popcorn Kernel as Affected by Moisture Content

Strength properties and dynamic coefficient of friction of popcorn kernels were evaluated as a function of moisture content in the range of 7.78–16.72 g/100 g dry solids. In order to determine strength properties of the kernels that are in terms of deformation at rupture point, rupture force, energy absorbed, hardness, and toughness of the popcorn kernels were quasi-statically loaded between two parallel plates. To determine frictional properties, friction tests were performed on aluminum, steel, and fiberglass surfaces. The values related to the strength properties, in general, decreased as the moisture content increased. On the other hand, the dynamic coefficient of friction of the popcorn kernels increased with increasing moisture content.     

Recent developments in cold plasma-based enzyme activity (browning,cell wall degradation,and antioxidant) in fruits and vegetables

According to the Food and Agriculture Organization of United Nations reports, approximately half of the total harvested fruits and vegetables vanish before they reach the end consumer due to their perishable nature. Enzymatic browning is one of the most common problems faced by fruit and vegetable processing. The perishability of fruits and vegetables is contributed by the various browning enzymes (polyphenol oxidase, peroxidase, and phenylalanine ammonia-lyase) and ripening or cell wall degrading enzyme (pectin methyl-esterase). In contrast, antioxidant enzymes (superoxide dismutase and catalase) assist in reversing the damage caused by reactive oxygen species or free radicals. The cold plasma technique has emerged as a novel, economic, and environmentally friendly approach that reduces the expression of ripening and browning enzymes while increasing the activity of antioxidant enzymes; microorganisms are significantly inhibited, therefore improving the shelf life of fruits and vegetables. This review narrates the mechanism and principle involved in the use of cold plasma technique as a nonthermal agent and its application in impeding the activity of browning and ripening enzymes and increasing the expression of antioxidant enzymes for improving the shelf life and quality of fresh fruits and vegetables and preventing spoilage and pathogenic germs from growing. An overview of hurdles and sustainability advantages of cold plasma technology is presented.     

Comparison of radiation‐induced hydrocarbons for the identification of irradiated perilla and sesame seeds of different origins

BACKGROUND: Perilla and sesame seeds, a rich source of energy, are commonly utilized in different forms in many countries. During the post‐harvest period, they are contaminated with insects as well as microbes that may have importance for keeping quality and quarantine, and thus they can be treated with ionizing radiation for insect disinfestation and microbial decontamination. Reliable and routine methods to identify whether or not a food has been irradiated are needed to help consumers' understanding of irradiated food and promote international trade. In the present study, fat‐derived hydrocarbons from irradiated perilla seeds and sesame seeds of Korean and Chinese origin were analyzed in order to identify irradiation treatment by comparing their properties during the post‐irradiation period. RESULTS: Gas chromatographic–mass spectrometric analysis showed that several saturated hydrocarbons, such as tetradecane, pentadecane, hexadecane and heptadecane, were found in the non‐irradiated control samples, while four radiation‐induced unsaturated hydrocarbons (R² = 0.647–0.997), such as 1,7,10‐hexadecatriene (C_16:3), 1,7‐hexadecadiene (C_16:2), 6,9‐heptadecadiene (C_17:2) and 8‐heptadecene (C_17:1), were detected in all irradiated samples at 0.5 kGy or higher, with variations according to sample and origin. Concentrations of all hydrocarbons were reduced during storage and could not be detected in 0.5 kGy irradiated Chinese sample of either seed after 8 months. CONCLUSION: Radiation‐induced hydrocarbons (C_{16:3, 16:2, 17:2, 17:1}) could be used as markers to identify irradiated perilla and sesame seeds of both Korean and Chinese origin at 1 kGy or higher for 8 months' storage at room temperature. Copyright © 2009 Society of Chemical Industry     

Antioxidant properties of 1,2,3,4,6-penta-O-galloyl-β-d-glucose from Elaeocarpus sylvestris var. ellipticus

The antioxidant potential of 1,2,3,4,6-penta-O-galloyl-β-d-glucose (PGG), isolated from Elaeocarpus sylvestris var. ellipticus, was investigated by various established systems based on cell-free and cell system experiments, such as radical detection, antioxidant enzyme assay, lipid peroxidation detection, and cell viability assay. PGG was found to quench the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and intracellular reactive oxygen species. PGG recovered the cellular antioxidant enzyme activities of superoxide dismutase, catalase, and glutathione peroxidase, which were reduced by H₂O₂ treatment, thereby resulting in the inhibition of lipid peroxidation. Cytoprotective effects of PGG were based on the results of DNA fragmentation, mitochondrial membrane potential (Δψ), apoptotic body formation, and caspase-3 activity. The results suggest that PGG protects cells against H₂O₂-induced cell damage via antioxidant properties.     

Microbial Succession and Metabolite Changes during Long‐Term Storage of Kimchi

Kimchi is often stored for a long period of time for a diet during the winter season because it is an essential side dish for Korean meals. In this study pH, abundance of bacteria and yeasts, bacterial communities, and metabolites were monitored periodically to investigate the fermentation process of kimchi for 120 d. Bacterial abundance increased quickly with a pH decrease after an initial pH increase during the early fermentation period. After 20 d, pH values became relatively stable and free sugars were maintained at relatively constant levels, indicating that kimchi fermentation by lactic acid bacteria (LAB) was almost completed. After that time, a decrease in bacterial abundance and a growth in Saccharomyces occurred concurrently with increased free sugar consumption and production of glycerol and ethanol. Finally, after 100 d, the growth of Candida was observed. Community analysis using pyrosequencing revealed that diverse LAB including Leuconostoc citreum, Leuconostoc holzapfelii, Lactococcus lactis, and Weissella soli were present during the early fermentation period, but the LAB community was quickly replaced with Lactobacillus sakei, Leuconostoc gasicomitatum, and Weissella koreensis as the fermentation progressed. Metabolite analysis using ¹H‐NMR showed that organic acids (lactate, acetate, and succinate) as well as bioactive substances (mannitol and gamma‐aminobutyric acid (GABA)) were produced during the kimchi fermentation, and Leuconostoc strains and Lactobacillus sakei were identified as the producers of mannitol and GABA, respectively. Practical Application In this study, we have shown that the growth inhibition of yeasts including Saccharomyces and Candida is necessary to extend the shelf life of kimchi in long‐term storage. Additionally, we have shown that a mixed culture of Leuconostoc strains and Lactobacillus sakei is necessary to produce kimchi that contains both mannitol and gamma‐aminobutyric acid.