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60 Years of Korean Meteorological Society on Climate Change
No full textThis paper aims to examine from various perspectives how domestic research studiesand projects related to climate change have been conducted to mark the 60th anniversary of theKorean Meteorological Society (KMS). The ???50-year History of the Korean MeteorologicalSociety???, published more than a decade ago, has never dealt with the history of development ofindividual fields of meteorology such as climate change. Therefore, it is of significance to look atthe history of research activities and studies achieved by KMS members in the area of climatechange over the past 60 years. The research on climate change in KMS is classified by era from thebeginning to the latest and the contents are examined by major research projects at that time. Duringthe past 60 years, climatological research in KMS has been mainly focused on general climate, synopticclimate, and applied climate (urban climate) until the 2000s. However, since the 1990s, climatechange has become an important area for climate research. The 2000s are the beginning era ofclimate change research, since the major projects and researches for climate change has begun in theperiod. The 2010s can be a time when climate change prediction and monitoring are expanded andrefined to meet the rapidly increasing demands for climate information from a wide range of areas.
We concluded that the development of the research capabilities of the society over the past 60 years,in particular in the past two decades, in the field of climate change research is remarkable
Copper with an atomic-scale spacing for efficient electrocatalytic co-reduction of carbon dioxide and nitrate to urea
No full textThe electrochemical co-reduction of carbon dioxide (CO2) and nitrate (NO3-) to urea via C-N bond coupling is a promising alternative to traditional industrial processes that are intensive in energy consumption and CO2 emission. However, due to the lack of suitable catalysts, the electrochemical process for urea synthesis suffers from low faradaic efficiency, current density, and product yield, which highlights the importance of developing new catalysts that work efficiently toward the co-reduction of CO2 and nitrate NO3- (CR-CO2/NO3-) and the corresponding C-N bond coupling reactions. Here, we report that copper (Cu) with atomic-scale spacings (d(s)) between copper facets can significantly improve the electrochemical synthesis of urea from CR-CO2/NO3-. We used the lithiation approach to create d(s) between the copper facets. We prepared four Cu samples with different d(s) values simply by controlling the degree of lithiation on each sample. Among the four samples, Cu with a d(s) close to 6 angstrom achieves a remarkably high urea yield rate of 7541.9 mu g h(-1) mg(cat)(-1) and a partial current density of 115.25 mA cm(-2), substantially greater than those of the bare Cu (urea yield rate of only 444.7 mu g h(-1) mg(cat)(-1) and urea partial current density of 1.96 mA cm(-2)) counterpart. Our density functional theory calculations suggest that compared with bare Cu, Cu with a d(s) of 6.0 angstrom significantly lowers the energy barrier for C-N coupling, enhancing the C-N bond formation kinetically and thermodynamically and therefore leading to much-improved urea formation from CR-CO2/NO3-
Inventor-licensee matchmaking for university technology licensing: A fastText approach
No full textAlthough many previous studies have explored university technology licensing, few have examined the value of quantitative data and scientific methods in improving operational efficiency. Focusing on the marketing phase of university technology licensing processes, this study proposes an analytical framework for inventor-licensee matchmaking by linking technological functions and business requirements. The proposed framework utilises fastText to construct a technological function-business requirement landscape, where similar technological functions and business requirements are located in close proximity. Potential pairs of inventors and licensees for technology licensing are identified through similarity analysis based on the constructed landscape. To validate the framework's effectiveness, an inventor-licensee matching rate is calculated by comparing the matchmaking results to actual technology licensing contracts. A case study covering 16,517 disclosed inventions and 565 licensed technologies from Sogang University confirms that the proposed analytical framework is useful in identifying potential inventor-licensee pairs. It can serve as a valuable complementary tool for university technology licensing in the era of open innovation
FunRank: Finding 1-Day Vulnerability with Call-Site and Data-Flow Analysis
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Intense multicycle THz pulse generation from laser-produced nanoplasmas
No full textWe present a novel scheme to obtain robust, narrowband, and tunable THz emission using a nano-dimensional overdense plasma target, irradiated by two counter-propagating detuned laser pulses. So far, no narrowband THz sources with a field strength of GV/m-level have been reported from laser-solid interaction (mostly half-or single-cycle THz pulses with only broadband frequency spectrum). From two- and three-dimensional particle-in-cell simulations, we find that the strong plasma current generated by the beat ponderomotive force in the colliding region, produces beat-frequency radiation in the THz range. Here we report intense THz pulses (f???30THz) with an unprecedentedly high peak field strength of 11.9 GV/m and spectral width (?? f/ f??? 5.3 %) , which leads to a regime of an extremely bright narrowband THz source of TW/cm2, suitable for various ambitious applications
Denitrification Performance and Bacterial Community Structure of Methanol and Mixed Carbon Sources
No full textDenitrifying bacteria convert nitrate to nitrogen gas using an external carbon source as an electron donor. The external carbon source affects the denitrification performance and bacterial community structure. Although methanol is a cheap and effective external carbon source, the addition of diverse carbon sources may improve the total nitrogen removal rate and biomass characteristics, such as settleability. In this study, denitrifying reactions were performed using solely methanol and mixed carbon sources of methanol, glucose, and acetate in a sequencing batch reactor. The denitrifying reactor using methanol resulted in a total nitrogen removal rate of 0.39 ?? 0.025 kg-N/m??-day while the suspended biomass transformed into dark brown granules. Methyloversatilis discipulorum had the highest predominance at 43.84%. The individual denitrifying biomasses, which were separately enriched with methanol, glucose, and acetate, showed the same total nitrogen removal performance of 0.39 ?? 0.016 kg-N/m??-day. However, the addition of mixed carbon sources showed an improved total nitrogen removal rate of 0.42 ?? 0.043 kg-N/m??-day, with the domination of Candidatus Saccaribacteria at 25.61%. The denitrifying granules turned pale yellow color. Influent COD/NO3--N ratios of 3.5, 5, and 7.5 exhibited COD/NO3--N consumptions of 4.3 ?? 0.4, 4.4 ?? 0.8, and 5.2 ?? 0.7, and the consistent predominance of Candidatus Saccharibacteria
Progressive formation of active and stable PtZn bimetallic nanoclusters by exsolution during propane dehydrogenation
No full textPtZn bimetallic nanoclusters on two-dimensional (2D) molecular sieves are attractive catalysts for propane dehydrogenation (PDH) owing to the ease of molecular diffusion, resistance to deactivation by coke deposition, and electronic promotion by Zn. Here, we report the progressive formation of highly active PtZn bimetallic nanoclusters on a Pt-modified zincosilicate with 2D delaminated MWW layers (PtZn-DML) under PDH condi-tions. The exsolution of Zn from the zincosilicate DML framework during PDH generates highly dispersed PtZn active sites and reduces the Lewis acidity of zincosilicate DML support, resulting in a high propane conversion (40.3%) comparable to thermodynamic equilibrium as well as extraordinary stability with a low deactivation rate (kd < 0.002 h-1) up to 13.6 days
Electrocatalysis of Selective Chlorine Evolution Reaction: Fundamental Understanding and Catalyst Design
No full textThe electrochemical chlorine evolution reaction (CER) is an important electrochemical reaction and has been widely used in chlor-alkali electrolysis, on-site generation of ClO-, and Cl-2-mediated electrosynthesis. Although precious metal-based mixed metal oxides (MMOs) have been used as CER catalysts for more than half a century, they intrinsically suffer from a selectivity problem between the CER and parasitic oxygen evolution reaction (OER). Hence, the design of selective CER electrocatalysts is critically important. In this review, we provide an overview of the fundamental issues related to the electrocatalysis of the CER and design strategies for selective CER electrocatalysts. We present experimental and theoretical methods for assessing the active sites of MMO catalysts and the origin of the scaling relationship between the CER and the OER. We discuss kinetic analysis methods to understand the kinetics and mechanisms of CER. Next, we summarize the design strategies for new CER electrocatalysts that can enhance the reactivity of MMO-based catalysts and overcome their scaling relationship, which include the doping of MMO catalysts with foreign metals and the development of nonprecious metal-based catalysts and atomically dispersed metal catalysts
Fatigue residual useful life estimation of Ni-base alloy weld with time-series data
No full textWe developed a fatigue residual useful life (RUL) prediction model using the available time-series fatigue data of Ni-base alloy welds via a long short-term memory (LSTM) network. The effects of some LSTM network hyperparameters on model performance were investigated through sensitivity studies. The LSTM network model outperformed multiple regression models when the LSTM model hyperparameters were appropriately tuned. However, the additional gain was insignificant, considering that the LSTM network was much more complex than multiple regression models. The best performance of the LSTM network model was achieved when the number of hidden units, input window size, and batch size were small and the number of LSTM layers was large
Minimizing the Carrier Collection Loss of the Neutral-Color Transparent Crystalline-silicon Solar Modules via Hybrid Electrode Design
No full textTransparent solar cells can be used where conventional solar cells are inapplicable, such as, in glass windows of buildings; however, reports on modularization, which is essential for their commercialization, are scarce. Here, a novel modularization method has been proposed for the fabrication of transparent solar cells and a 100-cm(2) neutral-color transparent crystalline-silicon solar module has been developed using a hybrid electrode comprising a microgrid electrode and an edge busbar electrode. The transparent solar module exhibits a power conversion efficiency (PCE) of 11.94 and 13.14% when connected in series and in parallel, respectively, with an average visible transmittance of 20%. Additionally, the module exhibits negligible losses in PCE (lower than 0.23%) in outdoor, mechanical-load, and damp-heat (at 85 degrees C/85% RH) stability tests, indicating high stability. The transparent solar module proposes here could facilitate the commercialization of transparent solar cells