Ga 2 O 3 based gas sensors have limited use at a temperature lower than 400 C because of their poor performances at low temperatures. Efforts to further improve their performances at room temperature are necessary. This study examines the sensing properties of surface-nitridated Ga 2 O 3 nanowires toward CO gas. Surface-nitridated Ga 2 O 3 nanowires were fabricated by thermal evaporation of GaN powders followed by thermal nitridation in an NH 3 atmosphere. Scanning electron microscopy and transmission electron microscopy showed that the GaN shell layer in a typical surface-nitridated nanowire had a thickness of $21 nm and excellent shell layer thickness uniformity. Multiple networked surface-nitridated Ga 2 O 3 nanowire sensors showed responses of 160-363% to CO concentrations of 10-200 ppm at 150 C. These responses were 1.6-3.1 fold stronger than those of pristine Ga 2 O 3 nanowire sensors at the same CO concentrations and stronger than those of many pristine metal oxide nanostructures and Ga 2 O 3 /metal oxide core-shell nanowires at similar temperatures. The results showed that the sensitivity of Ga 2 O 3 nanowires could be enhanced by simple ammoniation treatment. The enhanced response of the surface-nitridated Ga 2 O 3 nanowires to CO gas can be explained based on a potential barrier carrier transport mechanism combined with a surface depletion mechanism and excellent shell layer uniformity. Fig. 1 (a) SEM image and (b) XRD pattern of surface-nitridated Ga 2 O 3 nanowires.This journal is

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Pulsed electrochemical machining (PECM) has been conducted for invar (Fe-Ni) fine sheet consisting of 64 % Fe ions and 36 % Ni ions. Solutions of sodium chloride (NaCl), acetic acid (CH 3 COOH), sodium nitrate (NaNO 3 ), and sodium nitrite (NaNO 2 ) mixed with sodium tartrate (C 4 H 4 Na 2 O 6 ) were used as an electrolyte. First, the electrical conductivities of all electrolytes have been measured. As the concentration of each electrolyte increased, the electrical conductivities of electrolytes increased except for the acetic acid. The electrochemical machinability has been investigated using four types of electrolytes. The results of PECM show that the electrolyte which has the high electrical conductivity value leads to the low electrochemical machinability. The pulse waves which indicate the electrical characteristics during the PECM has been observed and it is confirmed that the passivating oxide film occur in PECM. To compare the capability of changing in transpassive state, the anode surface has been investigated. This study presents the relationship between electrical conductivity and electrical machinability. Moreover, the capacity of changing in transpassive state has been investigated as compared with four types of electrolytes. This study shows the possibility of applying invar fine sheet in PECM and contributes to determining the electrolyte for the process.

In this, study, the yellow clays were added to the nonwoven geotextiles to improve the removal effects of the toxic and organic components of the leachate solutions which are very dangerous to the men's health. 4 types of functional nonwoven geotextiles were manufactured with the different composition of yellow clays. We applied these functional nonwoven geotextiles to the waste landfill fields as a filtration material of leachate solutions and tested tensile properties before=after application. Chemical and biological resistances of these nonwoven geotextiles were also evaluated and the amounts of absorptions of toxic and organic components were compared to the simply manufactured polyester nonwoven geotextiles.

Objective: In this study, a questionnaire survey was conducted for doctors and patients to obtain basic data necessary for the development of an integrated medical system for idiopathic pulmonary fibrosis (IPF).Methods: Questionnaires were developed separately for doctors and patients through an expert group meeting. The survey subjects were recruited online and offline, and finally, responses from 231 doctors and 59 patients were used for statistical analysis.Results: The most important parts in the treatment of IPF for both doctors and patients were the “improvement of respiratory symptoms,” “improvement of quality of life,” and “prevention of disease progression.” Antifibrotic agents were prescribed at a high rate, and 100% of the specialists in Western medicine (WM) and 45.8% of patients reported experiencing side effects. As for the additional payment costs that patients considered as affordable for an integrated medical system, “under 50,000 won (about 38$)” was reported the most in both doctor and patient groups. With regard to the reasons for their reluctance to recommend an integrated medical system for IPF, specialists in WM responded highly to “uncertain evidence for treatment effectiveness.” Regarding complementary and alternative medicine therapies that can be beneficial in patients with IPF, “lifestyle management,” “diet management,” “herb,” “relaxation therapy,” and “psychotherapy” were ranked high in both doctor and patient groups.Conclusions: In this study, a questionnaire survey on IPF was conducted to review actual treatment status, analyze shortcomings, and identify considerations for the development of an integrated medical system for IPF in the future.