Bacterial community analysis in upflow multilayer anaerobic reactor (UMAR) treating high-solids organic wastes

A novel anaerobic digestion configuration, the upflow multi-layer anaerobic reactor (UMAR), was developed to treat high-solids organic wastes. The UMAR was hypothesized to form multi-layer along depth due to the upflow plug flow; use of a recirculation system and a rotating distributor and baffles aimed to assist treating high-solids influent. The chemical oxygen demand (COD) removal efficiency and methane (CH4) production rate were 89% and 2.10 L CH4/L/day, respectively, at the peak influent COD concentration (110.4 g/L) and organic loading rate (7.5 g COD/L/day). The 454 pyrosequencing results clearly indicated heterogeneous distribution of bacterial communities at different vertical locations (upper, middle, and bottom) of the UMAR. Firmicutes was the dominant (>70%) phylum at the middle and bottom parts, while Deltaproteobacteria and Chloroflexi were only found in the upper part. Potential functions of the bacteria were discussed to speculate on their roles in the anaerobic performance of the UMAR system

Experimental observation of hidden Berry curvature in inversion-symmetric bulk 2H-WSe2

We investigate the hidden Berry curvature in bulk 2H-WSe2 by utilizing the surface sensitivity of angle resolved photoemission (ARPES). The symmetry in the electronic structure of transition metal dichalcogenides is used to uniquely determine the local orbital angular momentum (OAM) contribution to the circular dichroism (CD) in ARPES. The extracted CD signals for the K and K' valleys are almost identical but their signs, which should be determined by the valley index, are opposite. In addition, the sign is found to be the same for the two spin-split bands, indicating that it is independent of spin state. These observed CD behaviors are what are expected from Berry curvature of a monolayer of WSe2. In order to see if CD-ARPES is indeed representative of hidden Berry curvature within a layer, we use tight binding analysis as well as density functional calculation to calculate the Berry curvature and local OAM of a monolayer WSe2. We find that measured CD-ARPES is approximately proportional to the calculated Berry curvature as well as local OAM, further supporting our interpretation.Comment: 6 pages, 3 figure

Real-Time Test-Bed System Development Using Power Hardware-in-the-Loop (PHIL) Simulation Technique for Reliability Test of DC Nano Grid

Since various power sources such as renewable energy and energy storage systems (ESSs) are connected to the DC grid, the reliability of the grid system is significant. However, the configuration of an actual DC grids for testing the reliability of the grid system is inconvenient, expensive and dangerous. In this paper, a test-bed system made up of a 20-kW DC nano grid and a control algorithm considering an external grid based on Power Hardware-in-the-Loop (PHIL) simulation are proposed to demonstrate the reliability of the DC grid. Using the PHIL simulation technique, target grids can be safely implemented with laboratory-level instruments and simulated by real-time simulators, which emulates grid operations that are similar to the actual grid. In addition, using the proposed control algorithm, the operations of grid-connected converters are demonstrated according to the grid-connected or islanding modes. Finally, the reliability of the simulated DC nano grid and the effectiveness of the grid-connected converter are verified using the PHIL simulation system with 3-kW prototype converters

The Perception of Urban Regeneration by Stakeholders: A Case Study of the Student Village Design Project in Korea

Urban regeneration by participatory methods is being discussed in many parts of the world, but conflicts between stakeholders emerge as a major challenge. In order to address this problem, a new approach to urban regeneration has been attempted in Korea. By targeting towns with university campuses, this project encourages active participation from university students as well as local residents. As a result of COVID-19 restrictions, the project adopted an online-based communication strategy. First, the online data was collected; second, the data for each participant was classified through data refinement; and third, the data analysis and data visualization were carried out at each stage using program R. The results revealed that the stakeholders exhibited different perceptions about the process, indicating a potential benefit of distinct role division for the success of the multiparty project. The significance of this study lies in the fact that it analyzes participants’ perceptions of urban regeneration using a text-mining process. The results of the study can serve as the basis for minimizing conflict and planning effective urban regeneration

Improvements of motion vector in variational echo tracking technique by correction of initial guess

Póster presentado en: 3rd European Nowcasting Conference, celebrada en la sede central de AEMET en Madrid del 24 al 26 de abril de 2019

Staphylococcal enterotoxin sensitization in a community-based population : a potential role in adult-onset asthma

Background: Recent studies suggest that Staphylococcus aureus enterotoxin sensitization is a risk factor for asthma. However, there is a paucity of epidemiologic evidence on adult-onset asthma in community-based populations. Objective: We sought to evaluate the epidemiology and the clinical significance of staphylococcal enterotoxin sensitization in community-based adult populations. Methods: The present analyses were performed using the baseline data set of Korean adult population surveys, consisting of 1080 adults (mean age=60.2years) recruited from an urban and a rural community. Questionnaires, methacholine challenge tests, and allergen skin tests were performed for defining clinical phenotypes. Sera were analysed for total IgE and enterotoxin-specific IgE using ImmunoCAP. Results: Staphylococcal enterotoxin sensitization (0.35kU/L) had a prevalence of 27.0%. Risk factors were identified as male sex, current smoking, advanced age (61years), and inhalant allergen sensitization. Current asthma was mostly adult onset (18years old) and showed independent associations with high enterotoxin-specific IgE levels in multivariate logistic regression tests. In multivariate linear regressions, staphylococcal enterotoxin-specific IgE level was identified as the major determinant factor for total IgE level. Conclusions and Clinical Relevance: Staphylococcal enterotoxin sensitization was independently associated with adult-onset asthma in adult community populations. Strong correlations between the enterotoxin-specific IgE and total IgE levels support the clinical significance. The present findings warrant further studies for the precise roles of staphylococcal enterotoxin sensitization in the asthma pathogenesis