• Title/Summary/Keyword: Primary air

Search Result 880, Processing Time 0.037 seconds

Characteristics of phenol degradation by using underwater dielectric barrier discharge plasma (수중 유전체 장벽 방전 플라즈마를 이용한 페놀의 분해 특성)

  • Shin, Gwanwoo;Choi, Seungkyu;Kim, Jinsu;Zhu, Qian;Weon, kyoungja;Lee, Sangill
    • Journal of Korean Society of Water and Wastewater
    • /
    • v.33 no.4
    • /
    • pp.243-250
    • /
    • 2019
  • This objective of this study was to investigate the degradation characteristics of phenol, a refractory substance, by using a submerged dielectric barrier discharge (DBD) plasma reactor. To indirectly determine the concentration of active species produced in the DBD plasma, the dissolved ozone was measured. To investigate the phenol degradation characteristics, the phenol and chemical oxygen demand (COD) concentrations were evaluated based on pH and the discharge power. The dissolved ozone was measured based on the air flow rate and power discharged. The highest dissolved ozone concentration was recorded when the injected air flow rate was 5 L/min. At a discharge power of 40W as compared to 70W, the dissolved ozone was approximately 2.7 - 6.5 times higher. In regards to phenol degradation, the final degradation rate was highest at about 74.06%, when the initial pH was 10. At a discharged power of 40W, the rate of phenol decomposition was observed to be approximately 1.25 times higher compared to when the discharged power was 70W. It was established that the phenol degradation reaction was a primary reaction, and when the discharge power was 40W as opposed to 70W, the reaction rate constant(k) was approximately 1.72 times higher.

A Basic Study on the Mobile Separator and Sorter Development of Small and Medium-sized Discharge Site's Mixed Construction Waste in Rural Area (농촌지역 혼합건설폐기물의 중·소규모 배출현장용 이동식 분리선별기 개발을 위한 기초연구)

  • Kim, Byung-Yun;Park, Ji-Sun
    • Journal of the Korean Institute of Rural Architecture
    • /
    • v.21 no.3
    • /
    • pp.17-24
    • /
    • 2019
  • This study aimed to develop a mobile separating and sorting device for discharge sites to separate and sort mixed construction waste generated in small and medium scale in small provincial cities into inorganic materials and combustible materials. The study results can be summarized as follows: 1) As a result of analyzing the existing domestic technology for the separating and sorting mixed construction waste, a device sorting the waste by fusing the vibration screen, disc screen, air blowing methods and the separating and sorting the combustible waste is applied in Korea. 2) In foreign countries, the air blowing, screen, gravity sorters are used for separating and sorting combustible waste in the same way as in Korea. Especially German T Company suggests a construction waste separating and sorting system using an optical sorter. 3) As for the test device for separating and sorting mixed construction waste to be buried in landfill, the processing capacity was set as 16 tons per day. 4) For separating and sorting inorganic materials by granularity, this study set a trommel with two types of diameter as a basic. To operate the mobile all-in-one system, the device is designed to locate a conveyor, a combustible waste conveying device, inside of the trommel. 5) The device is designed in a mobile mode under the concept of primary separating and sorting device, and it can be transported using a 2.5-ton truck minimum. The diameter and length of the trommel are designed to be within 1500mm and 3000mm, respectively. In a further study, an optimized separating and sorting technology is planned to be presented through an experimental study for processing efficiency analysis at the mixed construction waste site by manufacturing the pilot experiment facility reflecting the design elements in the result of this study.

Development and Quality Characteristics of Seasoned Dried Pen Shell Atrina pectinata Adductor (키조개(Atrina pectinata) 패주를 이용한 조미 중간수분제품의 제조 및 품질특성)

  • Hwang, Young-Sook;Hwang, Seok-Min;Oh, Kwang-Soo
    • Korean Journal of Fisheries and Aquatic Sciences
    • /
    • v.51 no.6
    • /
    • pp.632-639
    • /
    • 2018
  • To develop the high-value added seafood products from a regional speciality seafood, the seasoned dried pen shell Atrina pectinata adductor (SDPA) and seasoned smoke-dried pen shell adductor (SSPA) samples were prepared, and their optimal processing conditions, quality metrics, and shelf-life characteristics were examined. SDPA and SSPA samples were produced by thawing of frozen pen shell adductor, and cutting it into 6-7 mm slices, hot-air drying ($60^{\circ}C$, 20 min) or smoking ($110^{\circ}C$, 20 min), seasoning ($4^{\circ}C$, 12 h) with seasoning powder (60% sorbitol, 15% sucrose, 16% salt and 9.0% monosodium glutamate), hot-air drying ($60^{\circ}C$, 3 h), torching, vacuum-packaging in a laminated plastic film bag, heat treating with hot-water ($85^{\circ}C$, 15 min), and cooling. The moisture content of SDPA and SSPA samples was 44.5 and 43.0%, respectively, and the water activity was 0.845 and 0.842. The total amino acids in SDPA and SSPA samples were 20,986.8 and 21,312.4 mg/100 g, respectively, and the major amino acids in both products were aspartic acid, serine, glutamic acid, proline, glycine, alanine, valine, leucine, phenylalanine, lysine and arginine. The primary minerals were Na, S, K and P. Incubating tests indicated that the quality of SDPA and SSPA samples was maintained for 30 days of storage.

An Ozone-based Advanced Oxidation Process for an Integrated Air Pollution Control System (복합대기오염 저감 시스템을 위한 오존 고속산화 기반 고도산화공정)

  • Uhm, Sunghyun;Hong, Gi Hoon;Hwang, Sangyeon
    • Applied Chemistry for Engineering
    • /
    • v.32 no.3
    • /
    • pp.237-242
    • /
    • 2021
  • Simultaneous removal technologies of multi-pollutants such as particulate matters (PMs), NOx, SOx, VOCs and ammonia have received consistent attention due to the enhancement of pollutant abatement efficiency in addition to the stringent environmental regulation and emission standard. Pretreatment of insoluble NO by an ozone oxidation can be considered to be more effective route for saving space occupation as well as operation cost in comparison with that of traditional selective catalytic reduction (SCR) process. Moreover the primary advantage of ozone oxidation process is that the simultaneous removal with acidic gas including SOx is also available. Herein, we highlight recent studies of multi-pollutant abatement via ozone oxidation process and the promising research topics for better application in industrial sectors.

An Experimental Study on the Spray Characteristics of a Rotating Fuel Nozzle of a Slinger Combustor for Different Flow Rates and Rotating Speeds (슬링거 연소기 회전연료노즐의 유량과 회전수에 따른 분무특성에 대한 실험적 연구)

  • Shim, Hyeon-Seok;Bae, Jonggeun;Kim, Jupyoung;Kim, Shaun;Kim, Donghyun;Ryu, Gyongwon
    • Journal of the Korean Society of Propulsion Engineers
    • /
    • v.25 no.4
    • /
    • pp.59-70
    • /
    • 2021
  • An experimental study was conducted to observe the spray characteristics for different flow rates and rotating speeds of a rotating fuel nozzle of a slinger combustor. The water spray ejected from the nozzle orifice was visualized using a high-speed camera and a light source. It was confirmed that the atomization was improved, as the flow rate decreased and rotating speed increased. The characteristic maps for the spray characteristics and performance parameters showed that the aerodynamic Weber number and the liquid-air momentum flux ratio were associated with the liquid primary breakup, and the liquid-air momentum flux ratio and Rossby number were closely correlated with the liquid ejection mode.

Effects of Inhalation versus Total Intravenous Anesthesia on Postoperative Pulmonary Complications after Anatomic Pulmonary Resection

  • Lee, Soojin;Cho, Jeong Su;Kim, Eunsoo;Kim, Yeongdae;Lee, Jonggeun
    • Journal of Chest Surgery
    • /
    • v.55 no.1
    • /
    • pp.30-36
    • /
    • 2022
  • Background: No consensus exists regarding whether volatile anesthetics are superior to intravenous anesthetics for reducing postoperative pulmonary complications (PPCs) in patients undergoing general anesthesia for surgery. Studies of this issue focused on anatomic pulmonary resection are lacking. This study compared the effects of total intravenous anesthesia (TIVA) versus volatile anesthesia on PPCs after anatomic pulmonary resection in patients with lung cancer. Methods: This retrospective study examined the medical records of patients with lung cancer who underwent lung resection at our center between January 2018 and October 2020. The primary outcome was the incidence of PPCs, which included prolonged air leak, pneumonia, acute respiratory distress syndrome, empyema, atelectasis requiring bronchofiberscopy (BFS), acute lung injury (ALI), bronchopleural fistula (BPF), pulmonary embolism, and pulmonary edema. Propensity score matching (PSM) was used to balance the 2 groups. In total, 579 anatomic pulmonary resection cases were included in the final analysis. Results: The analysis showed no statistically significant difference between the volatile anesthesia and TIVA groups in terms of PPCs, except for prolonged air leak. Neither of the groups showed atelectasis requiring BFS, ALI, BPF, pulmonary embolism, or pulmonary edema after PSM. However, the length of hospitalization, intensive care unit stay, and duration of chest tube indwelling were shorter in the TIVA group. Conclusion: Volatile anesthetics showed no superiority compared to TIVA in terms of PPCs after anatomical pulmonary resection in patients with lung cancer. Considering the advantages of each anesthetic modality, appropriate anesthetic modalities should be used in patients with different risk factors and situations.

Experimental study on vehicle-induced unsteady flow in tunnel (터널에서 차량의 운행에 의해 생성되는 비정상 유동에 대한 실험적 연구)

  • Kim, Jung-Yup;Shin, Hyun-Joon
    • Journal of Korean Tunnelling and Underground Space Association
    • /
    • v.11 no.4
    • /
    • pp.411-417
    • /
    • 2009
  • The thermo-flow field in road tunnel is influenced by some facts such as piston effect of vehicle's move, operation of ventilation facilities, natural wind and buoyancy effect of fire plume. Among those, piston effect is one of primary causes for formation of air flow in road tunnel and has an effect on initial direction of smoke flow in tunnel fire. In this study to analyze the unsteady flow in the tunnel caused by the run of vehicle, the experimental study of vehicle-induced unsteady flow on a reduced-scale model tunnel is presented. While the three types of vehicle shape such as basic type of rectangular shape, diamond-head type and stair-tail type are changed, the pressure and air velocity variations with time are measured. The rising ratio of pressure and velocity are in order of "basic type of rectangular shape > stair-tail type > diamond-head type". The experimental results would be good data for development of a numerical method on the vehicle-induced unsteady tunnel flow.

Comparative Analysis of Runway Ultimate Capacity using Wake Turbulence Re-Categorization (Wake Turbulence RECAT을 적용한 활주로 절대 수용량 비교 분석)

  • Jeongwoo Park;Huiyang Kim;SungKwan Ku
    • Journal of Advanced Navigation Technology
    • /
    • v.25 no.6
    • /
    • pp.498-509
    • /
    • 2021
  • The wake turbulence at the wingtip of preceding aircraft may affect the normal operation of following aircraft. Aircraft are classified into four categories according to their maximum take-off weight, and horizontal separation is applied with this category matrix. The FAA and EUROCONTROL revealed that the magnitude and effect of preceding aircraft wake turbulence were smaller than the current distance separation minima suggest. This new information presents the opportunity for revising wake turbulence minima into seven categories (RECAT). This paper confirms the feasibility of implementing RECAT at major airports in South Korea using the draft of ICAO Doc. 10122. The paper also calculates the ultimate runway capacity of Incheon International Airport in South Korea using the Harris Model and comparatively analyzes the amount of runway capacity. As a result of the analysis, it was confirmed that the implementation of RECAT could increase the ultimate runway capacity of Incheon International Airport. This paper's calculation methods and results can be used as primary data for implementing RECAT in other airports.

Evaluating the Feasibility of a Ground Source Heat pump System for an Elderly Care Center through Simulation Approach (시뮬레이션을 통한 노인 요양 시설의 지열 히트펌프 시스템 적용 가능성 평가)

  • Byonghu Sohn;Young-Sun Kim;Seung-Eon Lee
    • Journal of the Korean Society for Geothermal and Hydrothermal Energy
    • /
    • v.19 no.4
    • /
    • pp.39-52
    • /
    • 2023
  • This study analyzes the energy performance of a elderly care center building and the applicability of a ground source heat pump (GSHP) system through simulation approach. For this purpose, a building information modeling (BIM) program and an energy performance calculation program were used. The impact of the mechanical ventilation system on the energy requirements of the heating and cooling system and the indoor environment was also analyzed, focusing on the change in indoor carbon dioxide (CO2) concentration, which is a representative indicator of the indoor environment (air quality). The simulation results showed that the target building exceeds Level 7 in terms of simulated primary energy consumption or actual energy consumption. In addition, it was analyzed that the target building could not maintain the indoor CO2 concentration below the standard concentration by natural ventilation through window opening alone. Combining the GSHP system with the mechanical ventilation system (Case B and Case C) can further reduce the overall energy consumption by reducing the amount of outdoor air introduced by opening windows. The cost savings compared to the baseline case are estimated to be 67.3% for Case A, 63.7% for Case B, 65.5% for Case C, and 42.5% for Case D. It is necessary to analyze the impact of various renewable energy technologies and passive ones on the energy performance and indoor environment of elderly care centers.

The Evaluation of Meteorological Inputs retrieved from MODIS for Estimation of Gross Primary Productivity in the US Corn Belt Region (MODIS 위성 영상 기반의 일차생산성 알고리즘 입력 기상 자료의 신뢰도 평가: 미국 Corn Belt 지역을 중심으로)

  • Lee, Ji-Hye;Kang, Sin-Kyu;Jang, Keun-Chang;Ko, Jong-Han;Hong, Suk-Young
    • Korean Journal of Remote Sensing
    • /
    • v.27 no.4
    • /
    • pp.481-494
    • /
    • 2011
  • Investigation of the $CO_2$ exchange between biosphere and atmosphere at regional, continental, and global scales can be directed to combining remote sensing with carbon cycle process to estimate vegetation productivity. NASA Earth Observing System (EOS) currently produces a regular global estimate of gross primary productivity (GPP) and annual net primary productivity (NPP) of the entire terrestrial earth surface at 1 km spatial resolution. While the MODIS GPP algorithm uses meteorological data provided by the NASA Data Assimilation Office (DAO), the sub-pixel heterogeneity or complex terrain are generally reflected due to coarse spatial resolutions of the DAO data (a resolution of $1{\circ}\;{\times}\;1.25{\circ}$). In this study, we estimated inputs retrieved from MODIS products of the AQUA and TERRA satellites with 5 km spatial resolution for the purpose of finer GPP and/or NPP determinations. The derivatives included temperature, VPD, and solar radiation. Seven AmeriFlux data located in the Corn Belt region were obtained to use for evaluation of the input data from MODIS. MODIS-derived air temperature values showed a good agreement with ground-based observations. The mean error (ME) and coefficient of correlation (R) ranged from $-0.9^{\circ}C$ to $+5.2^{\circ}C$ and from 0.83 to 0.98, respectively. VPD somewhat coarsely agreed with tower observations (ME = -183.8 Pa ~ +382.1 Pa; R = 0.51 ~ 0.92). While MODIS-derived shortwave radiation showed a good correlation with observations, it was slightly overestimated (ME = -0.4 MJ $day^{-1}$ ~ +7.9 MJ $day^{-1}$; R = 0.67 ~ 0.97). Our results indicate that the use of inputs derived MODIS atmosphere and land products can provide a useful tool for estimating crop GPP.