Gas sensors play a crucial role in monitoring harmful gas concentrations and air quality in real-time, ensuring safety and protecting health in both environmental and industrial settings. Additionally, they are essential in various applications for energy efficiency and environmental protection. As the demand for hydrogen refueling stations and hydrogen fuel cell vehicles increases with the growth of the hydrogen economy, accurate gas concentration measurement technology is increasingly necessary given hydrogen's wide explosion range. To ensure safety and efficiency, gas sensors must accurately detect a wide range of gas concentrations in real-world environments. This study presents two types of gas sensors with high sensitivity, stability, low cost, fast response time, and compact design. These sensors, based on volume and pressure analysis principles, can measure gas filling amounts, solubility, diffusivity, and the leakage of hydrogen, helium, nitrogen, and argon gases in high-density polyethylene charged under high-pressure conditions. Performance evaluation shows that the two sensors have a stability of 0.2 %, a resolution of 0.12 wt･ppm, and can measure gas concentrations ranging from 0.1 wt･ppm to 1400 wt･ ppm within one second. Moreover, the sensitivity, resolution, and measurement range of the sensors are adjustable. Measurements obtained from these sensors of gas filling amounts and the diffusivity of four gases showed consistent results within uncertainty limits. This system, capable of real-time gas detection and characterization, is applicable to hydrogen infrastructure facilities and is expected to contribute to the establishment of a safe hydrogen society in the future.

Gas sensors are crucial devices in various fields including industrial safety, environmental monitoring, gas infrastructure and medical diagnosis. These sensors measure specific gases in different environments, guaranteeing operational safety and efficiency through precise on-site measurements. Designed for high sensitivity, stability and reliability, gas sensors must also be cost-effective, quickly responsive and compact. To address these diverse requirements, we have developed two types of gas sensors based on the volumetric and the manometric method. These sensors operate by measuring the gas volume and the pressure changes, respectively, of the emitted gas. These sensors are capable of determining gas transport parameters such as gas uptake, solubility and diffusion coefficient for gas-charged polymers in high pressure environment. The sensors provide rapid responses within one second and can measure gas concentrations ranging from 0.01 wt ppm to 1500 wt ppm with adjustable sensitivity and measurement ranges. Performance evaluations demonstrate the sensors' reliability, adaptability to varying measurement ranges and stability under temperature and pressure fluctuations. As a result, this sensor system facilitates the real time detection and analysis of gas transport properties in pure gases including H₂, He, N₂, O₂ and Ar, making it suitable for pure gas sensing.

가스상의 체적분율과 압력강하는 기액이상류에 대한 이해와 예측에 있어서 매우 중요한 인자이다. 또한 그것들은 산업용 대용량의 열교환시스템 및 선박에 설치되는 보일러 및 냉동시스템의 설계에 있어서 필수적인 항목이다. 따라서 본 논문에서는 파이프의 모든 경사각도에서 기액이상류 가스상의 체적분율과 압력손실을 예측할 수 있는 이론적 해석 방법을 제시한다. 여기서의 이론적 해석은 2유체 층상류 모델을 기초로 하고 있다. 또한 이론적 해석결과와 기존의 실험결과와 비교한 결과에 대해서도 제시한다.

본 연구는 흉부 CT 검사 시 늑골 골절 환자를 대상으로 3차원 체적 재구성 기법의 유용성에 대해 알아보고자 하였 다. 임상에서 주로 이용 하는 재구성기법인 다평면재구성(MPR), 3차원 체적 영상 기법(VRT)을 적용하여 영상데이터 를 각 각 정량적 방법과 정성적 방법으로 비교 분석하였다. 재구성 영상의 분석 및 평가결과 늑골 골절 환자의 흉부 CT 검사 시 조영 전 원 자료를 이용하여 3차원 체적영상으로 재구성 하는 것이 보다 더 인공 음영을 최소화 시켰으며, 늑골 골절 판단 및 3차원 체적 영상 재구성 소요시간이 단축 됨을 알 수 있었다.