Sludge-based candidate reference materials for enhanced quality control of particulate processes in total organic carbon analysis for wastewater1.

Accurate analyses of total organic carbon (TOC) encompassing particulate organic carbon in wastewater are key for evaluating the behavior of particulate organic contaminants and maintaining the carbon mass balance throughout the wastewater treatment process. This study was conducted to develop candidate reference materials of environmental origin from excess sludge collected from wastewater treatment facilities, primarily receiving industrial wastewater and livestock manure as the main sources. Homogeneity and stability assessments for total carbon (TC) and TOC were conducted in the particle samples following the standardized procedures of ISO Guide 35 and ISO 13258. The results showed that high inorganic carbon (IC) content in particles, such as YJ(500) (IC: 29%), rendered them unsuitable for TOC quality control (QC), as they increased uncertainty in both homogeneity and stability assessments. Additionally, a13C NMR analysis revealed that samples with a high (O-alkyl)/(C-H-alkyl) ratio in their carbon structures exhibited relatively low stability. Through the homogeneity and stability assessments, a particle sample, YJ(100), was selected as the reference material (RM); the assigned values were as follows: 30.78% for TC and 27.94% for TOC, with uncertainties of 0.01% and 1.1%, respectively. Furthermore, considering sample transportation conditions, the safe storage period for the RM particles was determined to be 2 weeks under harsh conditions (at 40 °C). In our inter-laboratory test (n = 8) using the particle samples, we confirmed that the particle samples can effectively enhance particle processing QC and validate a proposed suspended solids pretreatment method. This study showcases valuable environmental particle sample production and evaluation, offering potential advancements in the QC of TOC analysis for wastewater samples.

Super multi-view near-eye display with a lightguide combiner.

We propose a lightguide-type super multi-view near-eye display that uses a digital micromirror device and a LED array. The proposed method presents three-dimensional images with a natural monocular depth cue using a compact combiner optics which consists of a thin lightguide and holographic optical elements (HOEs). Feasibility of the proposed method is verified by optical experiments which demonstrate monocular three-dimensional image presentation over a wide depth range. We also analyze the degradation of the image quality stemming from the spectral spread of the HOEs and show its reduction by a pre-compensation exploiting an adaptive moment estimation (Adam) optimizer.

Waveguide-type Maxwellian near-eye display using a pin-mirror holographic optical element array.

We propose a novel, to the best of our knowledge, waveguide-type optical see-through Maxwellian near-eye display for augmented reality. A pin-mirror holographic optical element (HOE) array enables the Maxwellian view and eye-box replication. Virtual images with deep depth of field are presented by each pin-mirror HOE, alleviating the discrepancy between vergence and accommodation distance. The compact form factor is achieved by the thin waveguide and HOE couplers.

Waveguide-type see-through dual focus near-eye display with a polarization grating.

Waveguide-type near-eye displays have useful properties such as compact form factor, lightweight and see-through capability. Conventional systems, however, support only a single image plane fixed at a certain distance, which may induce eye fatigue due to the vergence-accommodation conflict. In this paper, we propose a waveguide-type near-eye display with two image planes using a polarization grating. Two images with orthogonal polarizations propagate within the waveguide with different total internal reflection angles and form virtual images at different distances. The use of the polarization grating and two pairs of holographic optical elements enables dual image plane formation by a single waveguide with high transparency for the real scene. Optical experiments confirm the principle of the proposed optical system.

Low-k SiCOH Films Deposited with a Single Precursor 1,1,1,3,5,7,7,7 Octamethyl-3,5-Bis(trimethylsiloxy) Tetrasiloxane by Plasma Enhanced Chemical Vapor Deposition.

Low-dielectric-constant SiCOH films were deposited by plasma-enhanced chemical vapor deposition using 1,1,1,3,5,7,7,7-octamethyl-3,5-bis(trimethylsiloxy)tetrasiloxane (OMBTSTS) as a single precursor, and the characteristics were investigated. The relative dielectric constant (k) of the SiCOH films declined gradually from 3.57 to 1.90 with decreasing plasma power. The film with the lowest k, deposited at the lowest power of 10 W, showed the lowest leakage current density, with adequate mechanical strength (hardness: 0.98 GPa and elastic modulus: 8.56 GPa) for application in multilevel semiconductor interconnects. The chemistry of the OMBTSTS films was characterized by Fourier transform infrared spectroscopy to study the relation between the chemical and dielectric properties. The dielectric properties, such as the k value and leakage current density, could be explained by a quantitative relation between the Si-O stretching bond and hydrocarbon-related bonds, such as CH3 and Si-CH3 bonds, with lower polarizability in the SiCOH film. The refractive index, which is directly linked to the density of the film, was also investigated by ellipsometry. We consider OMBTSTS a promising candidate as a single precursor for fabricating low-k SiCOH films in the plasma-enhanced chemical vapor deposition system.

Development and validation of the Korean version of the medication regimen complexity index.

The medication regimen complexity index (MRCI), originally developed in English, is a reliable and valid tool to assess the complexity of pharmacotherapy. This study aimed to validate the Korean version of MRCI (MRCI-K). A cross-cultural methodological study comprising 335 discharged patients of a tertiary hospital in Korea was conducted. The translation process included translation into Korean by two clinical pharmacists, back translation by two native speakers, and a pretest of the tool, culminating in the Korean version of MRCI-K. Reliability analysis was assessed using inter-rater and test-retest reliability with 25 randomly selected patients. Convergent and discriminant validity analyses were conducted by correlating MRCI scores with medication number, age, sex, adverse drug reaction (ADR) reports, and length of stay. The criterion validity was confirmed through evaluation by a nine-member expert panel that subjectively ranked these regimens. The reliability analysis demonstrated excellent internal consistency (Cronbach's α = 0.977), and the intraclass correlation coefficient exceeded 0.90 for all cases. The correlation coefficient for the number of medications was 0.955 (P < 0.001). Weak significant correlations were observed with age and length of stay. The MRCI-K group with ADR reports scored higher (mean, 31.8) than the group without ADR reports (mean, 27.3). The expert panel's ranking had a stronger correlation with the MRCI ranking than the medication number ranking. MRCI-K has similar reliability and validity as MRCI and is useful for analyzing therapeutic regimens with potential applications in both practice and research in Korea.

Feedback control of an HBV model based on ensemble kalman filter and differential evolution.

In this paper, we derive efficient drug treatment strategies for hepatitis B virus (HBV) infection by formulating a feedback control problem. We introduce and analyze a dynamic mathematical model that describes the HBV infection during antiviral therapy. We determine the reproduction number and then conduct a qualitative analysis of the model using the number. A control problem is considered to minimize the viral load with consideration for the treatment costs. In order to reflect the status of patients at both the initial time and the follow-up visits, we consider the feedback control problem based on the ensemble Kalman filter (EnKF) and differential evolution (DE). EnKF is employed to estimate full information of the state from incomplete observation data. We derive a piecewise constant drug schedule by applying DE algorithm. Numerical simulations are performed using various weights in the objective functional to suggest optimal treatment strategies in different situations.

Deep-Plane Lipoabdominoplasty in East Asians.

BACKGROUND: The objective of this study was to develop a new surgical technique by combining traditional abdominoplasty with liposuction. This combination of operations permits simpler and more accurate management of various abdominal deformities. In lipoabdominoplasty, the combination of techniques is of paramount concern. Herein, we introduce a new combination of liposuction and abdominoplasty using deep-plane flap sliding to maximize the benefits of both techniques. METHODS: Deep-plane lipoabdominoplasty was performed in 143 patients between January 2007 and May 2014. We applied extensive liposuction on the entire abdomen followed by a sliding flap through the deep plane after repairing the diastasis recti. The abdominal wound closure was completed with repair of Scarpa's fascia. RESULTS: The average amount of liposuction aspirate was 1,400 mL (700-3,100 mL), and the size of the average excised skin ellipse was 21.78×12.81 cm (from 15×10 to 25×15 cm). There were no major complications such as deep-vein thrombosis or pulmonary embolism. We encountered 22 cases of minor complications: one wound infection, one case of skin necrosis, two cases of undercorrection, nine hypertrophic scars, and nine seromas. These complications were solved by conservative management or simple revision. CONCLUSIONS: The use of deep-plane lipoabdominoplasty can correct abdominal deformities more effectively and with fewer complications than traditional abdominoplasty.