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PurposeThe majority of legitimacy research has been conducted in low-power distance societies such as America, England, Australia, etc. We test the relative impact of normative and instrumental judgments on police legitimacy in a high-power distance society. It is hypothesized that in this context, individuals in high-power distance societies, such as South Korea, will put a larger emphasis on the instrumental model of legitimacy and less on the relational model of legitimacy.Design/methodology/approachThis study examines the pathways to police legitimacy and cooperation. Using a convenience sample of Korean college students, the impact of instrumental and normative pathways on the perception of police legitimacy is examined. Based on Hofstede's (2001) power-distance theory, we hypothesize that South Koreans, with relatively high-power distance, should emphasize the instrumental pathway of police legitimacy more compared to the normative pathway of police legitimacy.FindingsThe results indicated that opposite to what we have hypothesized, South Korean college students still emphasized the normative pathways to police legitimacy more importantly. While procedural justice significantly predicted both trustworthiness and obligation to obey the police, police effectiveness only significantly predicted trustworthiness and failed to predict obligation to obey.Originality/valueThe majority of police legitimacy research has been conducted in the Western context. A small amount of research focusing on non-Western settings has been conducted, but still requires more attention. The current research adds to the body of police legitimacy literature in the Korean context. Implications for future research and policy are discussed.

Thin film solid oxide fuel cells (TF–SOFCs) having anode–substrate nanostructure that was optimized for the low-temperature operation were fabricated. Nickel thin film anodes with four different anode thicknesses were deposited on anodic aluminum oxide templates, nanoporous substrates having two different pore sizes, by the sputtering method. Subsequently, a yttria-stabilized zirconia (YSZ) electrolyte and platinum cathode were deposited on them, which completed the entire fuel cell structure. The anode nanostructure of fuel cells in six combinations was analyzed by the cross-sectional view, surface microscopy method, and three-dimensional morphology observation. Those investigations enabled the anode nanostructure to be identified, such as the anode porosity and the roughness of the interface between anodes and electrolytes. Then, the six TF–SOFCs were electrochemically characterized in a 500 °C operating environment. The maximum power densities were obtained through the i–V–P curves, and the highest performance of 294.1 mW/cm2 was measured in the cell having a combination of 200 nm–sized porous aluminum anodic oxide (AAO) and 1200 nm–thick Ni anode. This showed up to 20.1% improvement over the other cells. EIS analysis showed that the optimized ohmic and faradaic resistance originated from each part of the unique TF–SOFC structure.

Solid oxide fuel cells are energy conversion devices that contribute to carbon neutrality, with the advantages of high efficiency, clean emissions production, and distributed power generation. However, the high operating temperature of the solid oxide fuel cells causes system stability and material selection problems. In this study, we aimed to lower the operating temperature of a solid oxide fuel cell by reducing the thickness of the electrolyte via sputtering. The deposition process was conducted under various pressure conditions to find the optimal sputtering process for a gas-tight YSZ thin-film electrolyte. The gas-tightness of the YSZ electrolytes was evaluated by observing the nanostructure and cell performance. As a result, the YSZ thin-film deposited at 3 mTorr showed the best gas-tightness and cell performance. At 500 °C, 1.043 V of OCV and a maximum power density of 1593 mW/cm2 were observed. Then, X-ray diffraction was used to calculate the residual stress of the YSZ films. As a result, it was confirmed that the gas-tight film showed compressive residual stress. Through this study, we were successful in developing a room-temperature YSZ electrolyte fabrication process with excellent gas-tightness and performance. It was also proven that there is a strong relationship between the gas-tightness and residual stress. This study is expected to contribute to cost reductions and the mass production of solid oxide fuel cells.

High-valent metal-oxo moieties have been implicated as key intermediates preceding various oxidation processes. The critical O–O bond formation step in the Kok cycle that is presumed to generate molecular oxygen occurs through the high-valent Mn-oxo species of the water oxidation complex, i.e., the Mn4Ca cluster in photosystem II. Here, we report the spectroscopic characterization of new intermediates during the water oxidation reaction of manganese-based heterogeneous catalysts and assign them as low-spin Mn(IV)-oxo species. Recently, the effects of the spin state in transition metal catalysts on catalytic reactivity have been intensely studied; however, no detailed characterization of a low-spin Mn(IV)-oxo intermediate species currently exists. We demonstrate that a low-spin configuration of Mn(IV), S = 1/2, is stably present in a heterogeneous electrocatalyst of Ni-doped monodisperse 10-nm Mn3O4 nanoparticles via oxo-ligand field engineering. An unprecedented signal (g = 1.83) is found to evolve in the electron paramagnetic resonance spectrum during the stepwise transition from the Jahn–Teller-distorted Mn(III). In-situ Raman analysis directly provides the evidence for Mn(IV)-oxo species as the active intermediate species. Computational analysis confirmed that the substituted nickel species induces the formation of a z-axis-compressed octahedral C4v crystal field that stabilizes the low-spin Mn(IV)-oxo intermediates. Understanding reaction intermediates provides a foundation for active electrocatalysts’ design, but it remains elusive for heterogeneous electrocatalysts. Here, the authors report the spectroscopic characterization of low-spin Mn(IV)-oxo as the active intermediates during electrochemical water oxidation.

We report the electrochemical performance and structural characteristics of porous nanostructured ceramic cathodes for thin-film solid oxide fuel cells (TF-SOFCs) based on yttria-stabilized zirconi...

Water oxidation is considered an important reaction to attain sustainable energy systems. Inspired by the biological Mn4CaO5 cluster, considerable effort has been devoted to developing efficient manganese-based heterogeneous catalysts for the water oxidation reaction. This review first describes the structural characteristics of the Mn4CaO5 cluster and synthetic manganese oxides. Important features related to the electrocatalytic activity of manganese-based heterogeneous catalysts as well as recent in situ spectroscopic results for intermediate characterization are then summarized. Current understanding of the reaction mechanism at the atomic level and the rate-determining step is highlighted. Finally, future perspectives for the development of highly active and stable manganese-based water-oxidizing catalysts are proposed.

The charge transport in the film-type electrocatalysts for the oxygen evolution reaction is a significant factor affecting the overall catalytic performance. For instance, transition metal oxide-ba...

BACKGROUND The changes in dietary habits can affect mental health problems, such as depressive disorder, due to the occurrence of diabetes. OBJECTIVE This study aimed to determine the effects of diabetes on mental health (Patient Health Questionnaire-9: PHQ-9). METHODS A secondary data analysis of cross-sectional design based on the raw data from KNHANES VII-1 was performed, which were disclosed by MOHW and KCDC. Of 8,150 respondents, 5,661 respondents aged ⩾ 20 years were included, thus excluding 2,489 respondents. Data were analyzed using an SPSS version 20.0 program. RESULTS The respondents scored high for diabetes diagnosis status (3.65), suicide planning status for a year (8.56), mental problem counseling for a year (7.80), and the degree of daily stress awareness (8.27) in PHQ-9. They scored higher for suicide planning status for a year, mental problem counseling for a year, and the degree of daily stress awareness than for diabetes diagnosis status in PHQ-9. Positive correlation was found among diabetes diagnosis status, suicide planning status for a year, mental problem counseling for a year, and daily stress awareness in PHQ-9 (p< 0.01). Diabetes diagnosis status (p< 0.01), suicide planning status for a year (p< 0.001), mental problem counseling for a year (p< 0.001), and the degree of daily stress awareness (p< 0.001) affected PHQ-9. CONCLUSION PHQ-9 for screening depressive disorder based on diabetes diagnosis status had low scoring distribution. However, because diabetes diagnosis status significantly affected PHQ-9 for depression screening, it is necessary to pay attention to health care related to diabetes. Further research should be conducted on the association with diverse causes of the low scoring distribution in PHQ-9 in relation to diabetes.

A high-performance solid oxide fuel cell (SOFC) stack technology is being developed, based on a design concept that incorporates prime-surface metallic interconnects with the versatility of stacking different types of single cells (sintered cells or metal-supported cells). A preliminary design of the prime-surface interconnect based on an egg-carton shape configuration has been advanced for this stack concept. Laboratory-scale prime-surface interconnects have successfully been fabricated by stamping and evaluated for mechanical loading, flow distribution and current collection properties. A process based on sputtering has been developed for fabricating supported thin-film (several micrometers thick) cells for this stack technology. Fabricated thin-film cells have shown desirable structural characteristics and exceptional performance on different fuels at reduced temperatures (550o-650oC). Sputtered cells (with yttria stabilized zirconia (YSZ) for the electrolyte, gadolinia-doped ceria (GDC) for the electrolyte/cathode interlayer, nickel-YSZ for the anode and lanthanum strontium cobalt iron perovskite (LSCF)–YSZ for the cathode) have exhibited peak power densities of ~1.7 W/cm2 and ~2.1 W/cm2 with hydrogen fuel and air at operating temperatures of 600oC and 650oC, respectively.

Electrochemical water oxidation is a key counter reaction in obtaining value-added chemicals by reduction in aqueous solution. However, slow kinetics is a problem in this process, so the quantitati...

In this study, the Y2O3 doping concentration of yttria stabilized zirconia (YSZ) thin film electrolyte deposited by plasma enhanced atomic layer deposition (PEALD) is optimized to maximize the performance of thin film solid oxide fuel cells (TF-SOFCs). The PEALD YSZ thin films are highly crystalline, and the Y2O3 concentration is controlled by changing the ratio between ZrO2 and Y2O3 ALD cycles. Electrochemical performances of TF-SOFCs are strongly dependent on the Y2O3 doping concentration in electrolytes. The cell with 10.7 mol% doped YSZ achieves the best performance (180 mW/cm2) at 450 °C due to decreased polarization loss because of its higher density of oxygen vacancies. These results demonstrate the effectiveness of PEALD process to deposit crystalline YSZ thin film electrolytes with optimal doping for high performance TF-SOFCs.

Performance of thin film solid oxide fuel cells (TF-SOFCs) were improved by inserting plasma enhanced atomic layer deposition (PEALD) of yttira-stabilized zirconia (YSZ) interlayers. By controlling the ratio between Y2O3 and ZrO2 in YSZ deposition supercycles, Y2O3 mol.% in YSZ films were changed. High Y2O3 contained PEALD YSZ interlayered cell showed higher maximum power density (123.6 mW/cm2 at 500 °C, 286.1 mW/cm2 at 550 °C) and smaller polarization resistance compared with reference Y2O3 concentrated PEALD YSZ interlayer cell. (108.5 mW/cm2 at 500 °C, 181.1 mW/cm2 at 550 °C) Exchange current densities of TF-SOFCs at 500 °C also improved ~ 59.3% at high Y2O3 concentrated PEALD YSZ interlayer cells. These phenomena caused by high density of oxygen vacancies in high Y2O3 concentrated PEALD YSZ interlayer, which helps oxygen incorporation reactions at cathode-interlayer interface. Therefore, cathodic polarization loss related with oxygen reduction reactions was decreased, and then, performance and exchange current density were improved. Results of this study imply that insertion of simple PEALD YSZ interlayer at cathode-electrolyte interface efficiently improves performance and electrochemical characteristics of TF-SOFCs.

The reaction mechanism of electrochemical chloride oxidation at neutral pH is different from that at acidic pH, in which a commercial chlor-alkali process has been developed. Different proton concentrations and accelerated hydrolysis of the generated chlorine into hypochlorous acid at high pH can change the electrokinetics and stability of reaction intermediates. We have investigated a unique reaction mechanism of Co3O4 nanoparticles for chloride oxidation at neutral pH. In contrast with water oxidation, the valency of cobalt was not changed during chloride oxidation. Interestingly, a new intermediate of Co-Cl was captured spectroscopically, distinct from the reaction intermediate at acidic pH. In addition, Co3O4 nanoparticles exhibited high selectivity for active chlorine generation at neutral pH, comparable to commercially available RuO2-based catalysts. We believe that this study provides insight into designing efficient electrocatalysts for active chlorine generation at neutral pH, which can be practically applied to electrochemical water treatment coupled to hydrogen production.

In this paper, we fabricate a thin film solid oxide fuel cell (SOFC) with a lanthanum strontium cobalt ferrite (LSCF) cathode which is coated with an Au layer by sputtering. The fabricated thin film SOFC has a 370-nm-thick Ni anode/880-nm-thick YSZ electrolyte/440-nm-thick LSCF cathode/130-nm-thick Au layer. The electrochemical performances of the thin film SOFC with the LSCF cathode coated with a 130-nm-thick Au layer and another SOFC without an Au layer are measured at the operating temperature of 600 °C. Since the LSCF cathode coated with a 130-nm-thick Au layer significantly lowers the sheet resistance (in-plane direction resistance), the peak power densities of the thin film SOFC with the LSCF cathode coated with a 130-nm-thick Au layer and the thin film SOFC with the LSCF cathode without a 130-nm-thick Au layer are 500 mW/cm2 and 49 mW/cm2, respectively. Due to the LSCF cathode coated with a 130-nm-thick Au layer, the peak power density of the thin film SOFC with the Au-coated LSCF cathode is 10 times higher than that of the LSCF cathode without Au layer.

Background/aim KRAS is one of the frequently mutated genes in human cancers and often relates with drug resistance and poor prognosis. PANAMutyper™ is a novel technology that integrates PNAClamp™ and PANA S-Melting™. In the present study, PANAMutyper™ and PNAClamp™ were compared for the detection of KRAS mutations using different samples of patients with malignant pleural effusion. Patients and methods A total of 103 patients (including 56 lung adenocarcinoma, 10 lung squamous carcinoma, 17 small cell lung cancer, 3 large cell lung cancer, 3 stomach cancer, 2 ovarian cancer, and others) with malignant pleural effusion were investigated using matched tumor tissue, cell block, and pleural effusion samples. The diagnostic performance of these two methods was compared. Results KRAS mutations were detected in 18 (17.5%) of 103 patients using tissue, cell block, and pleural effusion samples. All 18 patients with KRAS mutations were detected by PANAMutyper™ using any sample type, however, only 7 cases were detected by PNAClamp™. Among the subtypes of KRAS mutations, substitution in codon 12, 35G>T was the most frequent, followed by substitution in codon 12, 35G>A and codon 12, 34G>A. In pleural effusion specimens, PANAMutyper™ showed a better diagnostic performance compared to PNAClamp™. Conclusion PANAMutyper™ had a diagnostic superiority for the detection of KRAS mutations in patients with malignant pleural effusion compared to PNAClamp™, although there was a concordance between PANAMutyper™ and PNAClamp™ results. Therefore, PANAMutyper™ can be used for a more sensitive and accurate detection of KRAS mutations.

Thin film solid oxide fuel cells (TF-SOFCs) are attracting attention due to their ability to operate at comparatively lower temperatures (400-650 °C) that are unattainable for conventional anode-supported SOFCs (650-800 °C). However, limited cathode performance and cell scalability remain persistent issues. Here, we report a new approach of fabricating yttria-stabilized zirconia (YSZ)-based TF-SOFCs via a scalable magnetron sputtering process. Notable is the development and deposition of a porous La0.6Sr0.4Co0.2Fe0.8O2.95(LSCF)-based cathode with a unique fibrous nanostructure. This all-sputtered cell shows an open-circuit voltage of ∼1.0 V and peak power densities of ∼1.7 and ∼2.5 W/cm2 at 600 and 650 °C, respectively, under hydrogen fuel and air along with showing stable performance in short-term testing. The power densities obtained in this work are the highest among YSZ-based SOFCs at these low temperatures, which demonstrate the feasibility of fabricating exceptionally high-performance TF-SOFC cells with distinctive dense or porous nanostructures for each layer, as desired, by a sputtering process. This work illustrates a new, potentially low-cost, and scalable platform for the fabrication of next-generation TF-SOFCs with excellent power output and stability.

The electrochemical reduction of carbon dioxide (CO

A thin film solid oxide fuel cell (TF-SOFC) with a Ni anode on a nanoporous anodic aluminum oxide substrate was demonstrated. In our experiments, Ni was used as an anode material, while a very small amount of Pt was used as a cathode material, which reduced the thickness of the thin film cathode to 65 nm. In addition, a plasma-enhanced atomic layer deposition method was used to prepare a yttria-stabilized zirconia electrolyte. The open circuit voltage and the peak power density of the as-fabricated fuel cells, both of which were measured at 500 °C, were 1.04 V and 150 mW/cm2, respectively.

In this study, we investigate the possibility of using Ni-based anodes as alternatives to the Pt-based anodes for thin-film solid oxide fuel cells (SOFCs) operating at low temperatures. Anodes, electrolytes, and cathodes are sequentially sputtered onto a nanoporous substrate. The pure Ni anodes with modified nanostructures exhibit comparable performance as that of the optimized Pt anodes. Furthermore, a Ni/Ni-YSZ bilayer anode fabricated via a co-sputtering method exhibits approximately 37% higher peak power density than does the optimized Pt anode at 500 °C, demonstrating that noble metal anodes can be replaced by Ni-based anodes in low-temperature SOFCs by optimizing the anode nanostructure.

Thin film solid oxide fuel cells (TF-SOFCs) are one of the promising portable power sources in terms of rapid on/off, compact system volume, and high power density. This paper reviews fabrications, and designs of TF-SOFCs operating the temperature range of 300-500°C. The fabricating processes of both the electrolyte and the electrode via chemical vapor depositions and physical vapor depositions are discussed. The two platforms for designing TF-SOFCs are described: porous substrate and free-standing structures.

Background/Aims The progression and development of congestive heart failure is still considered a large problem despite the existence of revascularization therapies and optimal, state-of-the-art medical services. An acute myocardial infarction (AMI) is a major cause of congestive heart failure, so researchers are investigating techniques to complement primary percutaneous coronary intervention (PCI) or thrombolytic therapy to prevent congestive heart failure after AMI. Methods Twenty-six patients with successful PCI for acute ST-segment elevation anterior wall myocardial infarction were assigned to either a control group (n = 12) or a bone marrow mesenchymal stem cells (BM-MSC) group (n = 14). The control group received optimum post-infarction treatment, and the BMSC group received intracoronary delivery of autologous BMSC at 1 month after PCI with the optimum medical treatment. The primary endpoint was a left ventricular ejection fraction (LVEF) change from baseline to 4-month follow-up, as determined via myocardial single-photon emission computed tomography (SPECT). Results The global LVEF at baseline (determined 3.5 ± 1.5 days after PCI) was 35.4 ± 3.0% in the control group and 33.6 ± 4.7% in the BM-MSC group. BMSC transfer enhanced left ventricular systolic function primarily in anterior wall myocardial segments adjacent to the LAD infarcted area. Four months later, via SPECT, global LVEF had increased by 4.8 ± 1.9% in the control group and 8.8 ± 2.9% in the BM-MSC group (p = 0.031). The cell transfer did not increase the risk of adverse clinical events, in-stent restenosis, or proarrhythmic effects. The echocardiographic evaluation also revealed a significant increase in the LVEF value from baseline to the 4-month (9.0 ± 4.7 and 5.3 ± 2.6%, p = 0.023) and 12-month (9.9 ± 5.2% and 6.5 ± 2.7%, p = 0.048) follow-up in the BM-MSC group but not in the control group. Conclusions Intracoronary administration of autologous BM-MSC was tolerable and safe with significant improvement in LVEF at 4-month (SPECT and echocardiography result) and 12-month (echocardiography result only) follow-up in patients with anterior AMI.

Nickel-Samaria Doped Ceria (Ni-SDC) cermet anodic thin films of about 500 nm were prepared on Scandia Stabilized Zirconia (ScSZ) electrolyte supports via reactive radio frequency (RF) sputtering. Anode deposition was done at room temperature, and the background sputtering gas was a reactive mixture of Ar : O2/80 : 20. The oxide conducting fuel cell configuration was completed by screen printing of lanthanum strontium manganite (LSM/YSZ) cathodes on the other side of the ScSZ supports. High resolution transmission electron microscopy (HR-TEM) of the cermet anode revealed an arranged nanostructure, with patterned ceria enclosing the nickel molecules in porous media. These highly ordered anodes were tested under (i) H2 and (ii) a product fuel of CO2 electro-reduced via industrial waste carbon (IWC). IWC fuel performance matched the H2 fuel performance in terms of peak power density and longevity, with an added lower fuel cost advantage. HR-TEM and scanning electron microscope (SEM) 2D images were utilized to simulate the reaction kinetics of the nanostructured porous thin film cermet anode. The reported high electrochemical performance was proved to result from the high density of triple-phase boundaries, arranged nanostructure and high contiguity of the special design of the nano-anodes. Experimental and simulation results were coherent with each other, especially for IWC operated SOFCs working at or above 700 °C.

In this paper, we investigate the role of a graphene layer for polymer electrolyte fuel cells (PEFCs) which require an ultrathin protective layer for copper bipolar plates. The graphene layer was deposited by chemical vapor deposition using CH 4 at 830 °C. We examined the deposited graphene layer to characterize microstructural properties using a Raman spectroscopy microscope and a secondary electron microscope. During the electrochemical tests, the current–voltage–power (I–V–P) performance of the single cell using the copper bipolar plate with the graphene layer was highly stable for 5 h, while the I–V–P performance of the single cell using the pure copper bipolar plate (without the graphene layer) was much lower. We conclude that the graphene layer acts as a very thin passivation layer on the copper bipolar plate of a PEFC.