A new type of liquid junction-free reference electrode system is devised by employing solvent-processible polymer membranes. The membranes are formulated with either a one-component silicone rubber or an aromatic-type polyurethane as the matrixes. The optimized formulations incorporate both cation- and anion-exchange sites (i.e., potassium tetrakis(p-chlorophenyl)borate and tridodecylmethylammonium chloride) and, in the case of silicone rubber, a plasticizer. The silicone rubber-based membrane, while possessing minimal response toward most ions, is found to display a near-Nernstian response to pH change. The aromatic polyurethane matrix formulation, however, is not sensitive to pH over a wide range (i.e., pH 2−12) and is shown to exhibit only a small emf variation (within ±2 mV) toward a wide variety of salts added even at very high concentrations (i.e., up to 0.1 M). Potentiometric emf responses of ISEs (e.g., Na+, K+, Ca2+, Cl-), whether paired with a polymer membrane-based reference electrode or with a conventional liquid junction-type reference electrode, are shown to be remarkably similar within the precision of the measurement setup. The feasibility of adapting the proposed reference electrode to the planar solid-state sensor format is also demonstrated.

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To develop planar microchemical pCO2 sensing devices with improved electrochemical properties, we combined two advanced technologies. One is a differential sensor arrangement to simplify the microfabrication procedure by employing pH-sensitive gas-permeable membranes, and the other is the use of an enzyme (carbonic anhydrase) to shorten total measurement time by accelerating the rate of CO2 hydration. The adhesion of the polyurethane-matrix gas-permeable membrane is enhanced significantly by incorporating a silanizing reagent (silicon tetrachloride), improving the stability and extending sensor lifetime. The proposed differential pCO2 microelectrodes exhibited significantly improved performance in their preconditioning period, response and recovery times, stability, response slope, and lifetime.

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Current studies on online gender-based hate speech have focused on legal regulations and countermeasures. In this study, we analyzed, using a data mining technique, comments on news articles about gender issues published on web portals. Our analysis of articles published by various newspaper companies on Naver and Daum revealed that hate speech in comments was significantly higher for articles reporting on specific events related to gender issues than for general articles on gender issues. This trend is consistent for articles across all news companies, regardless of political orientation. However, web portals have the power to regulate gender-based hate speech on their sites. Daum operates a reporting system for discrimination and hate speech and has significantly fewer hate speech postings compared to Naver, which lacks such a system. This study empirically analyzed the changes in the quantity of gender-based hate speech and found that web portals, commonly classified as bystanders or gatekeepers, can play a functional role in reducing online gender-based hate speech.