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Industrial control systems (ICSs) used to be operated in closed networks, that is, separated physically from the Internet and corporate networks, and independent protocols were used for each manufacturer. Thus, their operation was relatively safe from cyberattacks. However, with advances in recent technologies, such as big data and internet of things, companies have been trying to use data generated from the ICS environment to improve production yield and minimize process downtime. Thus, ICSs are being connected to the internet or corporate networks. These changes have increased the frequency of attacks on ICSs. Despite this increased cybersecurity risk, research on ICS security remains insufficient. In this paper, we analyze threats in detail using STRIDE threat analysis modeling and DREAD evaluation for distributed control systems, a type of ICSs, based on our work experience as cybersecurity specialists at a refinery. Furthermore, we verify the validity of threats identified using STRIDE through case studies of major ICS cybersecurity incidents: Stuxnet, BlackEnergy 3, and Triton. Finally, we present countermeasures and strategies to improve risk assessment of identified threats.

Objective Especially in emergency departments (EDs), a lack of internal medicine (IM) residents in charge causes difficulties in medical care and ED overcrowding. Thus, protocols without IM residents in EDs is needed. This study aimed to investigate changes in medical care when emergency medicine residents replaced the roles of IM residents. Methods This study was conducted at a single-site ED of a university medical center. The study group contained patients admitted to the IM department between September and December 2015, during which IM residents were absent in the ED. The control group contained patients admitted to the IM department between September and December 2014, during which IM residents were present in the ED. Changes in medical care between the presence and absence of IM residents in the ED were studied by comparing admission rates from the ED, length of ED stay, duration of hospitalization, and concordance of diagnoses between admission and discharge by the IM department. Results The study group contained 2,341 patients; the control group contained 2,215 patients. Admission rates from the ED increased by 53.4% (95% confidence interval [CI], P

Abstract This study introduces a novel groundwater pollution index (GPI) formulated through compositional data analysis (CoDa) and robust principal component analysis (RPCA) to enhance groundwater quality assessment. Using groundwater quality monitoring data from sites impacted by the 2010–2011 foot-and-mouth disease outbreak in South Korea, CoDa uncovers critical hydrochemical differences between leachate-influenced and background groundwater. The GPI was developed by selecting key subcompositional parts (NH4 +-N, Cl-, and NO3--N) using RPCA, performing the isometric log-ratio (ILR) transformation, and normalizing the results to environmental standards, thereby providing a more precise and accurate assessment of pollution. Validated against government criteria, the GPI has shown its potential as an alternative assessment tool, with its reliability confirmed by receiver operating characteristic curve analysis. This study highlights the essential role of CoDa, especially the ILR -transformation, in overcoming the limitations of traditional statistical methods that often neglect the relative nature of hydrochemical data. Our results emphasize the utility of the GPI in significantly advancing groundwater quality monitoring and management by addressing a methodological gap in the quantitative assessment of groundwater pollution.

Terahertz (THz) waves occupy the electromagnetic spectrum between microwave and infrared radiation, with frequencies typically ranging from 0.1 to 10 THz. Compared with other optic and electronic tools, this frequency range allows for unique sensing applications such as nondestructive, label‐free, and fast detection. Despite the promising features of THz sensing applications, the dimensional mismatch between THz wavelength and nanoscale agents hinders practical applications, especially in biosensing and chemical sensing. Several recent studies propose that engineered THz resonators, such as split ring resonators, linear dipole and slot antennas, and nanogap loop antennas, enhance the sensitivity for detecting trace amounts of target molecules, such as viruses and explosives. When combined with near‐field imaging techniques in the THz range, these THz nanosensors may revolutionize our understanding of complex nanoscale systems, including 2D materials, as researchers can observe quantum dynamics directly in molecules, mobile carriers in semiconductors, THz quantum nonlocal effects, and dynamics of excitons and polaritons at THz frequencies. Additionally, THz biomolecular sensors are also discussed, where the sensor platforms will lead to a great impact in the advancement of ultrasmall‐quantity characterization of proteins, label‐free diagnosis of Alzheimer's disease, and conformational dynamics of biomolecules in their aqueous environment.

Double buffer layers composed of (AlxGa1−x)2O3/Ga2O3 structures were employed to grow a Sn-doped α-Ga2O3 epitaxial thin film on a sapphire substrate using mist chemical vapor deposition. The insertion of double buffer layers improved the crystal quality of the upper-grown Sn-doped α-Ga2O3 thin films by blocking dislocation generated by the substrates. Rapid thermal annealing was conducted for the double buffer layers at phase transition temperatures of 700–800 °C. The slight mixing of κ and β phases further improved the crystallinity of the grown Sn-Ga2O3 thin film through local lateral overgrowth. The electron mobility of the Sn-Ga2O3 thin films was also significantly improved due to the smoothened interface and the diffusion of Al. Therefore, rapid thermal annealing with the double buffer layer proved advantageous in achieving strong electrical properties for Ga2O3 semiconductor devices within a shorter processing time.

Bound states in the continuum, for decades a theoretical curiosity, have more recently found application in nanophotonic platforms due to their high quality factors and spatial confinement. Here, the authors review recent progress in the development of active and passive photonic devices exploiting these properties.

Abstract Herein, an unprecedented report is presented on the incorporation of size-dependent gold nanoparticles (AuNPs) with polyvinylpyrrolidone (PVP) capping into a conventional hole transport layer, poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS). The hole transport layer blocks ion-diffusion/migration in methylammonium-lead-bromide (MAPbBr3)-based perovskite light-emitting diodes (PeLEDs) as a modified interlayer. The PVP-capped 90 nm AuNP device exhibited a seven-fold increase in efficiency (1.5%) as compared to the device without AuNPs (0.22%), where the device lifetime was also improved by 17-fold. This advancement is ascribed to the far-field scattering of AuNPs, modified work function and carrier trapping/detrapping. The improvement in device lifetime is attributed to PVP-capping of AuNPs which prevents indium diffusion into the perovskite layer and surface ion migration into PEDOT:PSS through the formation of induced electric dipole. The results also indicate that using large AuNPs (> 90 nm) reduces exciton recombination because of the trapping of excess charge carriers due to the large surface area.

Though laser action has been reported for optical bound states in the continuum (BIC) cavities with high quality factors, these BIC lasers lacked practical applicability. Here, the authors report an ultralow-threshold super-BIC laser featuring merged symmetry-protected and accidental BICs.

A transparent twistable and stretchable MoO3/Au/MoO3 electrode is demonstrated by Choi et al. for organic light-emitting diodes. The device fabricated on thin elastomer shows enhanced EQE with minimum efficiency roll-off owing to the improved charge injection and heat dissipation from the substrate.

To delineate a livestock manure-derived groundwater plume (LDGP) in agro-livestock farming areas with the extensive use of chemical fertilizers, multilevel monitoring wells (MLWs) were installed for depth-specific sampling of groundwater, and then hydrochemical, nitrate N-O isotopic and microbiological data of shallow groundwater collected from the MLWs were evaluated with the help of multivariate statistical tools. The LDGP was distinguished from the pervasive agricultural contamination based on δ15Nnitrate (10‰). Fecal coliforms and Escherichia coli were not observed in the LDGP, whereas bovine enterovirus type 2 was detected at a sample collected at a depth of 18 m below ground level (bgl) downgradient manure piles, indicating a potential virus risk. Among hydrochemical parameters, Ca2+, Mg2+, Na+, Cl- and SiO2(aq) were shown to be effective indicators to trace the LDGP. On the other hand, nitrate was not effective to discriminate the LDGP because of denitrification in deep parts (>6 m bgl) within the LDGP, although nitrate contamination was serious at shallow parts (≤6 m bgl; 62.4 to 119.1 mg/L, median 97.9 mg/L). Thus, an integrated hydrochemical index consisting of Ca2+, Mg2+, Na+, Cl- and SiO2(aq) was suggested based on the result of principal component analysis with isometric log-ratio transformed data to delineate the LDGP in shallow unconsolidated aquifers overlying silicate bedrocks, and a threshold of the index was determined to be 1.17. The application of the index to three other agro-livestock farming areas with prevalent agricultural contamination successfully distinguished the groundwater samples within the LDGP (11 of 40 samples) that showed the index values exceeding the threshold and a median δ15Nnitrate of 12.5 ‰. The study results show that the hydrochemical index can be used for the quick evaluation of a LDGP in agro-livestock farming areas given its cost efficiency and easily accessible analysis devices for water chemistry compared to isotopes, although the broad use of the index to determine LDGPs needs to be further verified by application to various geology and land uses. Livestock manures should be carefully managed to protect groundwater resources, including impermeable covers above or beneath the manure piles, given the potential risk of virus at deep parts and nitrate at shallow parts within the LDGP. The methodology to select hydrochemical indicators for distinguishing a LDGP and the combination of the indicators to develop an index suggested in this study will be useful to build new indices adapted to local conditions.

Little is known about the effects of applying amendments on soil for immobilizing metal(loid)s on the soil microbial community. Alterations in the microbial community were examined after incubation of treated contaminated soils. One soil was contaminated with Pb and As, a second soil with Cd and Zn. Red pepper stalk (RPS) and biochars produced from RPS in either N2 atmosphere (RPSN) or CO2 atmosphere (RPSC) were applied at a rate of 2.5% to the two soils and incubated for 30 days. Bacterial communities of control and treated soils were characterized by sequencing 16S rRNA genes using the Illumina MiSeq sequencing. In both soils, bacterial richness increased in the amended soils, though somewhat differently between the treatments. Evenness values decreased significantly, and the final overall diversities were reduced. The neutralization of pH, reduced available concentrations of Pb or Cd, and supplementation of available carbon and surface area could be possible factors affecting the community changes. Biochar amendments caused the soil bacterial communities to become more similar than those in the not amended soils. The bacterial community structures at the phylum and genus levels showed that amendment addition might restore the normal bacterial community of soils, and cause soil bacterial communities in contaminated soils to normalize and stabilize. Keywords: Bacterial diversity, Community structure, Charcoal, Engineered biochar, Potentially toxic element

The hydrogeochemical properties of bottled waters (n = 37) were examined to evaluate the factors governing their quality and to suggest the natural background levels (NBLs) of groundwater. The bottled waters were sourced from bedrock aquifers of various geological types and analyzed for 14 physicochemical parameters and 48 trace elements. The bottled waters mainly consisted of the Ca-HCO3 type with low TDS (mean = 158.4 mg/L; n = 33) regardless of geological type, indicating low degrees of water–rock interaction. The results of principal component analysis (PCA) showed that these waters were characterized by the dissolution of calcite and Ca-plagioclase (PC1) and the weathering of Na-plagioclase and cation exchange (PC2). The PCA results with low concentrations of TDS and F (mean = 0.4 mg/L) revealed that the waters represent slightly mineralized groundwater, probably because the boreholes were installed in fractured aquifers, avoiding high F concentrations (>1.5 mg/L). The 90th percentiles for the Ca-HCO3 type bottled waters were proposed as the NBLs for Korean groundwater for 11 major elements and 20 trace elements. The NBLs of NO3 (7.9 mg/L) and F (0.9 mg/L) were similar to the 90th percentiles of EU bottled waters (n = 1785), implying the suggested NBLs are acceptable for groundwater quality management.

This study examined the microstructural gradation in Sn-doped, n-type Ga2O3 epitaxial layers grown on a two-inch sapphire substrate using horizontal hot-wall mist chemical vapor deposition (mist CVD). The results revealed that, compared to a single Ga2O3 layer grown using a conventional single-step growth, the double Ga2O3 layers grown using a two-step growth process exhibited excellent thickness uniformity, surface roughness, and crystal quality. In addition, the spatial gradient of carrier concentration in the upper layer of the double layers was significantly affected by the mist flow velocity at the surface, regardless of the dopant concentration distribution of the underlying layer. Furthermore, the electrical properties of the single Ga2O3 layer could be attributed to various scattering mechanisms, whereas the carrier mobility of the double Ga2O3 layers could be attributed to Coulomb scattering owing to the heavily doped condition. It strongly suggests the two-step-grown, lightly-Sn-doped Ga2O3 layer is feasible for high power electronic devices.

The utility of nanowires for all-optical operation has been limited by a lack of coupling scheme with band selectivity. Here, the authors introduce a nanowire geometric superlattice that allows controlled, narrow-band guiding in silicon nanowires through direct coupling of a Mie resonance with a bound guided state.

Abstract In this review, we introduce novel plasmonic and metamaterial devices based on one-dimensional subwavelength nanostructures with cylindrical symmetry. Individual single devices with semiconductor/metal core/shell or dielectric/metal core/multi-shell structures experience strong light–matter interaction and yield unique optical properties with a variety of functions, e.g., invisibility cloaking, super-scattering/super-absorption, enhanced luminescence and nonlinear optical activities, and deep subwavelength-scale optical waveguiding. We describe the rational design of core/shell cylindrical nanostructures and the proper choice of appropriate constituent materials, which allow the efficient manipulation of electromagnetic waves and help to overcome the limitations of conventional homogeneous nanostructures. The recent developments of bottom-up synthesis combined with the top-down fabrication technologies for the practical applications and the experimental realizations of 1D subwavelength core/shell nanostructure devices are briefly discussed.

Non-Hermitian optical systems have been shown to sustain lasing when they go from a PT-symmetric to a PT-symmetry-broken phase. Here, Kimet al. study this phase transition of lasing modes in partially graphene-covered coupled microcavities and show tuning of an exceptional point.

Several Bacillus species were isolated from rice field soils, and 16S rRNA gene sequence analysis showed that Bacillus cereus was the most abundant. A strain named BC1 showed antifungal activity against Rhizoctonia solani. Bacteriophages infecting strain BC1 were isolated from the same soil sample. The isolated phage PK16 had an icosahedral head of 100 ± 5 nm and tail of 200 ± 5 nm, indicating that it belonged to the family Myoviridae. Analysis of the complete linear dsDNA genome revealed a 158,127-bp genome with G + C content of 39.9% comprising 235 open reading frames as well as 19 tRNA genes (including 1 pseudogene). Blastp analysis showed that the proteins encoded by the PK16 genome had the closest hits to proteins of seven different bacteriophages. A neighbor-joining phylogenetic tree based on the major capsid protein showed a robust clustering of phage PK16 with phage JBP901 and BCP8-2 isolated from Korean fermented food.

Flexible, millimetre-scale systems and devices require embedded, reliable micrometre-scale components, which can be challenging to achieve for optical sensors. Here, the authors design a photonic crystal nanolaser and demonstrate its use in measuring strain.