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The purpose of this study was to develop synbiotic materials and to apply them to the puffed grain products using electrostatic spraying technology. Lactic acid bacteria were isolated from Kimchi and selected through tests of acid resistance, bile salt resistance and γ-aminobutyric acid (GABA) content. The isolated Lactobacillus brevis CFM21 produced highest GABA production up to a concentration of 926.42 μg/mL when grown in MRS broth containing 0.8% MSG. The possibility of coated grains as a prebiotic material was evaluated Confocal laser scanning micro scopy (CLSM). Rice bran extract containing 2% dextrose, 2% soytone, 0.2% potassium chloride, 0.6% MSG was produced 524.77 μg/mL of GABA. Citrus sinensis oil showed the highest antibacterial activity against Clostridium perfringens Electrostatic spray showed much higher effectiveness than conventional spray in coating the puffed grain product through CLSM. Applying Rice bran culture and Citrus sinensis oil to puffed grain product using electrostatic spray could contribute to promote intestinal health of consumers.

Background To evaluate the current status of emotional exhaustion and peritraumatic distress of healthcare workers (HCWs) in the COVID-19 pandemic, and identify factors associated with their mental health status. Methods An online survey involving 1068 of consented HCWs that included nurses, physicians, and public health officers was conducted in May 2020. Descriptive statistics and multivariate regression analyses were performed on the collected data. Results Although no significant difference in peritraumatic distress was observed among the surveyed HCWs, the workers’ experience of emotional exhaustion varied according to work characteristics. Respondents who were female, older, living with a spouse, and/or full-time workers reported higher levels of emotional exhaustion. Public health officers and other medical personnel who did not have direct contact with confirmed patients and full-time workers had a higher level of peritraumatic distress. Forced involvement in work related to COVID-19, worry about stigma, worry about becoming infected, and perceived sufficiency of organizational support negatively predict emotional exhaustion and peritraumatic distress. Conclusions Job-related and emotional stress of HCWs should not be neglected. Evidence-based interventions and supports are required to protect HCWs from mental illness and to promote mental health of those involved in the response to the COVID-19 pandemic.

We demonstrate the tungsten disulfide (WS2) thin film catalysts prepared by the sulfurization of vacuum deposited WO3 thin films for efficient hydrogen production with over 90% Faradaic efficiency. The 23-nm-thick WS2 thin film catalyst heterojunction with p-type silicon photocath-ode could exhibit a photocurrent density of 8.3 mA/cm2 at 0 V versus a reversible hydrogen electrode (RHE), a low onset potential of 0.2 V versus RHE when photocurrent density reaches -1 mA/cm2 and long-term stability over 10 h. The enhanced catalytic activities of WS2/p-Si photocathodes compared with the bare p-Si photocathode originate from a number of edge sites in the synthesized polycrystalline thin films, which could act as hydrogen evolution catalyst.

The twisted nematic liquid crystal cell was developed by using a CYTOP-transferred graphene sheet as an electrode and an alignment layer. A graphene layer was synthesized by chemical vapor deposition and transferred onto a plastic substrate using a fluoropolymer known as CYTOP. As the ion-beam treatment time increased, the sheet resistance increased from 500 to 1100 Ω/sq., while the water contact angle decreased from 110.5° to 69.7°. The increased intensities of the D and G′ bands and the appearance of D + D″ and D + G′ bands in the Raman spectra indicated the formation of defects because of the ion-beam treatment. An ion-beam exposure time of 15 s was found to be the most effective for the production of CYTOP-transferred graphene and for achieving high contrast in operating cells. The ion beam detached F from the CYTOP-transferred graphene layer, and the resulting exposure of the C=C bond on the graphene surface affected the alignment of liquid crystal molecules. Based on these results, the technique described here has applications in novel, high-performance liquid crystal displays that do not require indium-tin-oxide electrodes and polyimide alignment layers. Sheets synthesized by chemical vapor deposition were transferred and simultaneously doped using fluoropolymer supporting layers.

The characteristic differences between MoS2 and WS2 nanosheets and nanodots are investigated. The nanosheets were formed by liquid-phase sonication, while the nanodots were formed by breaking the nanosheets through heating the solvent ethylene glycol. The nanosheets and nanodots were approximately 0.7–2 nm thick, with slight deviation. Most of the nanosheets were longer than 100 nm, and most of the nanodots were shorter than 5 nm. As the bulk materials were transformed into nanosheets and/or nanodots, the absorption peaks and Raman peaks shifted to shorter wavelengths. Photoluminescence peaks were observed at 500 and 445 nm in the MoS2 and WS2 samples smaller than 100 nm. In the X-ray diffraction spectra, only the (002) peak was present in the nanosheets, while no peak was detected for the nanodots due to their small size. No detectable differences between the nanosheets and nanodots were observed in the transmission electron micrographs, synchrotron radiation photoemission spectra, or work function measu...

We have demonstrated that amine and alkyl groups, applied by a simple spin-coating method, can provide an n-type doping effect on graphene sheets. The organic compounds used in this work are based on amine, phenyl amine, butylphenyl amine, benzoylphenyl amine, and tolylvinylphenyl amine groups. The increases in sheet resistance, decreases in transmittance and work function, and shifts of the G peak to higher wavenumbers and the 2D peak to lower wavenumbers in the Raman spectra indicate that graphene was doped to n-type after the graphene sheets were spin-coated by the amine-based compounds. In particular, graphene doped with butylphenyl amine showed the strongest n-type effect among all of the samples because butylphenyl amine has the strongest binding energy with graphene sheets and disperses in nonpolar solvents, suggesting that the binding energy with graphene sheets and the degree of dispersion in solvents are important factors in the doping process. Molecular calculations based on density functional ...

The particle size distribution (PSD) of the debris bed is a major parameter influencing its coolability with respect to the two-phase pressure drop of the porous media. Most studies have focused on representative particle diameter as opposed to size distribution. Based on a severe accident situation (strong two-phase convection), we introduced a rearrangement of small particles and developed a corresponding size distribution formula by modifying the Rosin-Rammler distribution. A minimum particle diameter model was proposed as a function of dryout heat flux (DHF) based on a minimum fluidization velocity concept. In addition, a truncated Rosin-Rammler distribution was developed and a Sauter Mean Diameter (SMD) was formulated in the form of the gamma function with a new parameter: the minimum particle diameter (Dmin). Sensitivity analysis of DHF in a 1-D top flooded debris bed showed two notable results for the effect of Dmin on coolability. First, Dmin significantly reduced DHF uncertainty due to the distribution constant. Moreover, the calculated DHF increased by introducing the concept of a minimum particle diameter. In conclusion, treatment of small particles in the debris bed is essential for determining debris bed coolability. Additionally, the truncated Rosin-Rammler distribution could be utilized to provide the precise SMD in a porous media.

An inorganic lead halide perovskite film, CsPbI3, used as an absorber in perovskite solar cells (PSCs) was optimized by controlling the annealing temperature and the layer thickness. The CsPbI3 layer was synthesized by one-step coating of CsI mixed with PbI2 and a HI additive in N,N-dimethylformamide. The annealing temperature of the CsPbI3 film was varied from 80 to 120 °C for different durations and the thickness was controlled by changing the spin-coating rpm. After annealing the CsPbI3 layer at 100 °C under dark conditions for 10 min, a black phase of CsPbI3 was formed and the band gap was 1.69 eV. Most of the yellow spots disappeared, the surface coverage was almost 100%, and the rms roughness was minimized to 3.03 nm after annealing at 100 °C. The power conversion efficiency (PCE) of the CsPbI3 based PSC annealed at 100 °C was 4.88%. This high PCE value is attributed to the low yellow phase ratio, high surface coverage, low rms roughness, lower charge transport resistance, and lower charge accumulation. The loss ratio of the PCE of the CH3NH3PbIxCl3−x and CsPbI3 based PSCs after keeping in air was 47 and 26%, respectively, indicating that the stability of the CsPbI3 based PSC is better than that of the CH3NH3PbIxCl3−x based PSC. From these results, it is evident that CsPbI3 is a potential candidate for solar cell applications.

The need for lead-free piezoceramics has caused a renewal of interest in BaTiO₃-based systems. Recently, it was found that ceramics in the (Ba,Ca)(Zr,Ti)O₃ system have properties comparable to those of Pb(Zr,Ti)O₃. However, these ceramics require rather high sintering temperatures of 1450-1550℃. In this work, the effect of TiO₂ and CuO addition on the sintering behavior, microstructure, dielectric and piezoelectric properties of (Ba 0.85 Ca 0.15 )(Zr0.1Ti 0.9 )O₃ (BCTZ) ceramics will be discussed. BCTZ ceramics were prepared by the mixed oxide route and 1 ㏖ % of TiO₂ or CuO was added. Undoped and doped ceramics were sintered at 1350℃ for 1-5 h. CuO was found to be a very effective sintering aid, with samples sintered for 1 h at 1350℃ having a bulk density of 95% theoretical density; however the piezoelectric properties were greatly reduced, probably due to the small grain size.

Organometallic halide perovskites have attracted much attention as a promising material for high-efficiency absorber in photovoltaic devices. It is based on organic-inorganic light absorbing semiconducting material with a perovskite polycrystalline structure, CH3NH3PbX3, where X is halogenatoms (Cl, Br, I, or combination of some of them). The poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) was usually used as a hole extraction layer in planar type perovskite photovoltaic cells. However, PEDOT:PSS showed several disadvantages such as hygroscopic properties and a highly acidic suspension, which result in poor stability in air. In this respect, we have investigated the possibility of two-dimensional materials including MoS2, WS2, and graphene oxide (GO) as a hole extraction layer in perovskite photovoltaic cells. MoS2 and WS2 layers with a polycrystalline structure were synthesized by a chemical deposition method using uniformly spin-coated (NH4)MoS4 and (NH4)WS4 precursor solutions. GO was made by following Hummer’s method. Raman spectra, transmission electron microscope image, and x-ray diffraction data confirmed the well-synthesis of two-dimensional materials. The device structure is indium tin oxide/PEDOT:PSS or MoS2 or WS2 or GO/CH3NH3PbIxCl3-x/bathocurione/LiF:Al. The PCE values of PEDOT:PSS, GO, MoS2 and WS2-based one are measured to be 9.93, 9.62, 9.53 and 8.02 %, respectively. These result indicated that two-dimensional materials could replace the PEDOT:PSS layer for the improvement of device stability.