Activity of reducing steel slag of EAF

Reducing steel slag (RSS) was mainly acquired from five electric-arc furnace (EAF) steelmaking plants (among them, the products of two plants were carbon steel and those of other plants were stainless steel) for research tests. The chemical properties, compound compositions, activities and contents of main expansive compounds were tested. The results showed that the field sampled RSS had a very high crystallinity and hydraulicity with main chemical compositions close to those of Portland cement. It can be known from the study that in case of C/S ratio higher than 2.0, the main compound compositions are C₂S, C₃S, C₂F and f-CaO. However, after the RSS was stored for six months, an obvious variation occurred with potential pre-hydration in RSS, where the SO₃ content was slightly reduced and the compressive activity index was obviously higher than that at the 28th day.     

3D Localization for Launch Vehicle Using Virtual TOA and AOA of Ground Stations

Wireless Personal Communications - Generally, a ground telemetry station for a launch vehicle (LV) includes a tracking function only; therefore, position measurements for LV depend on received...     

Potential of a lactic acid bacterial starter culture with gamma-aminobutyric acid (GABA) activity for production of fermented sausage

The ability of lactic acid bacterial starter cultures to produce gamma-aminobutyric acid (GABA) during sausage fermentation was studied. Among 305 strains of lactic acid bacteria isolated from kimchi samples, 11 strains were selected as starter candidates based on the following criteria: growth speed, pH lowering ability, and biogenic amine productivity including GABA-producing activity. During in vitro tests, the Y8 (Lactobacillus brevis), O52, and KA20 strains produced 39.00 ± 1.36, 49.73 ± 3.80, and 64.59 ± 0.61 mg/kg of GABA, respectively. Interestingly, although isolate Y8 showed low productivity in vitro, the GABA content it produced during in situ tests (61.30 ± 2.61 mg/kg) was similar to that produced by isolate PM3 (L. brevis) used as positive control (69.64 ± 2.20 mg/kg). Therefore, isolate Y8 was selected as the best functional starter culture for the production of fermented sausage because it exhibited rapid growth, safety, and abundant GABA productivity.     

Cobalt Assisted Synthesis of IrCu Hollow Octahedral Nanocages as Highly Active Electrocatalysts toward Oxygen Evolution Reaction

Development of oxygen evolution reaction (OER) catalysts with reduced precious metal content while enhancing catalytic performance has been of pivotal importance in cost‐effective design of acid polymer electrolyte membrane water electrolyzers. Hollow multimetallic nanostructures with well‐defined facets are ideally suited for saving the usage of expensive precious metals as well as boosting catalytic performances; however, Ir‐based hollow nanocatalysts have rarely been reported. Here, a very simple synthetic scheme is reported for the preparation of hollow octahedral nanocages of Co‐doped IrCu alloy with readily tunable morphology and size. The Co‐doped IrCu octahedral nanocages show excellent electrocatalytic activity and long‐term durability for OER in acidic media. Notably, their OER activity represents one of the best performances among Ir‐based acidic OER catalysts.     

Oxidation of 17alpha-ethinylestradiol with Mn(III) and product identification

With increasing concern about the contamination of aquatic environments by estrogenic pollutants, removal of synthetic estrogens such as 17alpha-ethinylestradiol (EE2) has been widely studied, especially with respect to the treatment methods. However, the degradation products have rarely been identified. The purpose of this study was to identify structurally the oxidation products of EE2. Mn(III) was used as an oxidizing agent. To obtain sufficient oxidation products for HPLC, LC-MS and NMR spectroscopy, a highly concentrated solution of EE2 (1mM) was prepared in a mixture of water and a water-miscible organic solvent. From HPLC of the reaction products, a single compound (I) was found to be predominant. From LC-MS, its molecular mass was found to be 294, and two hydrogens were believed to have been removed from EE2 (M.W. 296) to form a C=C . The structure of compound I (position of the double bond) was determined using 1H NMR, 13C NMR, H-H COSY, HSQC and HMBC. As minor products, isomeric dimers (M.W. 590) of EE2, as well as the products (M.W. 588) in which EE2 was coupled to compound I were also formed during the Mn(III)-mediated oxidation of EE2.     

Memory characteristics of a self-assembled monolayer of Pt nanoparticles as a charge trapping layer

A self-assembled monolayer of Pt nanoparticles (NPs) was studied as a charge trapping layer for non-volatile memory (NVM) applications. Pt NPs with a narrow size distribution (diameter ～4?nm) were synthesized via an alcohol reduction method. The monolayer of these Pt NPs was immobilized on a SiO(2) substrate using poly(4-vinylpyridine) (P4VP) as a surface modifier. A metal-oxide-semiconductor (MOS) type memory device with Pt NPs exhibits a relatively large memory window of 5.8?V under ± 7?V for program/erase voltage. These results indicate that the self-assembled Pt NPs can be utilized for NVM devices.