• Title/Summary/Keyword: PITT

Search Result 17, Processing Time 0.028 seconds

An Experimental Study of the Effect of the Test-well Arrangement on the Partitioning Interwell Tracer Test for the Estimation of the NAPL Saturation (지하수 유동 방향에 대한 관정배열이 분배추적자 시험에 미치는 영향 분석)

  • Kim, Bo-A;Kim, Yongcheol;Yeo, In Wook;Ko, Kyung-Seok
    • Journal of Soil and Groundwater Environment
    • /
    • v.19 no.3
    • /
    • pp.111-122
    • /
    • 2014
  • Partitioning interwell tracer test (PITT) is a method to quantify and qualify a site contaminated with NAPLs (Non-Aqueous Phase Liquids). Analytical description of PITT assumes that the injection-pumping well pair is on the line of the ambient groundwater flow direction, but the test-well pair could frequently be off the line in a real field site, which could be an erroneous factor in analyzing PITT data. The purpose of this work is to study the influence of the angle of the test-well pair on the ambient groundwater flow direction based on the result from PITT. From the experiments, it was found that the obliqueness of the test-well pair to the ambient groundwater flow direction could affect the tracer test resulting in a decreased NAPL estimation efficiency. In case of an oblique arrangement of the test-well pair to the ambient flow direction, it was found that the injection of a chase fluid could enhance the estimation efficiency. An increase of the pumping rate could enhance the recovery rate but it cannot be said that a high pumping rate can increase the test efficiency because a high pumping rate cannot give partitioning tracers enough time to partition into NAPLs. The results have a implication that because the arrangement of the test-well pair is a controlling factor in performing and interpreting PITT in the field in addition to the known factors such as heterogeneity and the source zone architecture, flow direction should be seriously considered in arranging test-well pair.

Partitioning Interwell Tracer Test for NAPL Source Characterization: A General Overview

  • Lee, Tony R.;A. Lynn Wood;Jeong, Seung-Woo
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
    • /
    • 2002.04a
    • /
    • pp.159-162
    • /
    • 2002
  • Innovative and nondestructive characterization techniques have been developed to locate and quantify nonaqueous phase liquids (NAPLs) in the vadose and saturated zones in the subsurface environment. One such technique is the partitioning interwell tracer test (PITT). The PITT is a simultaneous displacement of partitioning and non-partitioning tracers through a subsurface formation. Partitioning tracers will partition into the NAPL during their transport through NAPL-contaminated formations. Mean travel times of partitioning and non-partitioning tracers are used to estimate the quantity of NAPL encountered by the displaced tracer pulse. Travel times are directly proportional to the partitioning coefficient and the volume of NAPL contacted in the subsurface environment. This paper discusses the conceptual background, design and implementation of PITTs. (This document has not been subjected to Agency review and therefore does not necessarily reflect the views of the Agency, and no official endorsement should be inferred.)

  • PDF

Charge/Discharge Mechanism of Multicomponent Olivine Cathode for Lithium Rechargeable Batteries

  • Park, Young-Uk;Shakoor, R.A.;Park, Kyu-Young;Kang, Ki-Suk
    • Journal of Electrochemical Science and Technology
    • /
    • v.2 no.1
    • /
    • pp.14-19
    • /
    • 2011
  • Quasi-equilibrium profiles are analyzed through galvanostatic intermittent titration technique (GITT) and potentiostatic intermittent titration technique (PITT) to study the charge/discharge mechanism in multicomponent olivine structure ($LiMn_{1/3}Fe_{1/3}Co_{1/3}PO_4$). From GITT data, the degree of polarization is evaluated for the three regions corresponding to the redox couples of $Mn^{2+}/Mn^{3+}$, $Fe^{2+}/Fe^{3+}$ and $Co^{2+}/Co^{3+}$. From PITT data, the current vs. time responses are examined in each titration step to find out the mode of lithium de-intercalation/intercalation process. Furthermore, lithium diffusivities at specific compositions (x in $Li_xMn_{1/3}Fe_{1/3}Co_{1/3}PO_4$) are also calculated. Finally, total capacity ($Q^{total}$) and diffusional capacity ($Q^{diff}$) are obtained for some selected voltage steps. The entire study consistently confirms that the charge/discharge mechanism of multicomponent olivine cathode is associated with a one-phase reaction rather than a biphasic reaction.

Performance Analysis of Autorotation(2) : Performance of High Speed Autorotaion (자동회전의 성능해석(2) : 고속 자동회전의 성능)

  • Kim, Hak-Yoon
    • Journal of the Korean Society for Aeronautical & Space Sciences
    • /
    • v.40 no.1
    • /
    • pp.12-22
    • /
    • 2012
  • Performance variation of autorotating rotor was investigated. The shaft angle of the rotor is reduced while the flight velocity is increased. The BO-105 helicopter rotor blade was replaced by untwisted NACA 0012 airfoil and the rotor was simulated by using Transient Simulation Method(TSM) to judge the autorotation region for the variables. To simulate the compressibility effect at high speed flight, two-dimensional aerodynamic data was analyzed by compressible Navier-Stokes solver and Pitt/Peters inflow theory was adopted to simulate the induced velocity field. Thrust and lift coefficients, lift to drag ratio variations were investigated, also the lift and power were compared to those of BO-105 helicopter. Sharing lift and power between the autorotating rotor and wing was considered when the compound aircraft concept is introduced.

Trim Range and Characteristics of Autorotation(I): Rotor Speed Limit and Pitch Range (자동회전의 트림 범위와 특성(I): 로터 스피드 한계와 피치범위)

  • Kim, Hak-Yoon;Choi, Seong-Wook
    • Journal of the Korean Society for Aeronautical & Space Sciences
    • /
    • v.39 no.6
    • /
    • pp.487-497
    • /
    • 2011
  • Numerical analysis has been performed to investigate the rotor speed and pitch range variations when the airspeed is increased in autorotation. Transient Simulation Method(TSM) was used to obtain the steady states of autorotation. The rotor blade was analyzed by the two-dimensional compressible Navier-Stokes solver in order to adapt to the airspeed increase and the results were used in the transient simulation method. Meanwhile, the Pitt/Peters inflow theory was used to supply the induced velocity fields. For the prescribed torque equilibrium state, the combinations of velocity, shaft angle, and pitch angle were produced to investigate the rotor speeds and variable ranges. The rotor tip Mach number and rotor speed were correlated and the trim range of pitch angle was observed with respect to the shaft angle decrease.

Trim Range and Characteristics of Autorotation(II): Advance Ratio Variation and Flapping Characteristics (자동회전의 트림 범위와 특성(II): 전진비 변화와 플래핑 특성)

  • Kim, Hak-Yoon;Choi, Seong-Wook
    • Journal of the Korean Society for Aeronautical & Space Sciences
    • /
    • v.39 no.6
    • /
    • pp.498-504
    • /
    • 2011
  • The flapping characteristics and advance ratios at torque equilibrium state of autorotation were investigated when the airspeed, shaft angle, and pitch angle were varied. To simulate the airspeed increase, the aerodynamic data analyzed by using the compressible Navier-Stokes solver and Pitt/Peters inflow theory were used. Transient Simulation Method(TSM) was used to catch the torque equilibrium states. The maximum flapping angles at torque equilibrium state were correlated to the airspeed, shaft angle, and pitch angle. By comparing flapping behavior to the variation of advance ratio, the phenomenon that the extension of reverse flow area of retreating blade affects the characteristics of autorotation was qualitatively considered.

Future Networking Technology of SDN (미래 네트워킹 기술 SDN)

  • Yoon, B.Y.;LEE, B.C.;Pitt, Dan
    • Electronics and Telecommunications Trends
    • /
    • v.27 no.2
    • /
    • pp.129-136
    • /
    • 2012
  • OpenFlow 기술은 기존의 폐쇄적인 네트워킹 기술을 개방형 네트워킹 기술로 변화시켜서 새로운 네트워킹 기술 발전을 위한 기반을 제공하였다. OpenFlow 기술의 상용화 및 표준화를 촉진시키기 위해서 설립된 ONF(Open Networking Foundation)는 네트워킹 기술을 컴퓨팅 기술로 재해석하고 OpenFlow 기술을 기반으로 SDN(Software-Defined Networking) 기술을 정의하였다. SDN 기술은 네트워크 비용 및 복잡성을 근본적으로 해결하는 기술로, 기존 네트워킹 기술의 하드웨어 및 소프트웨어 기술을 근본적으로 변화시키는 미래인터넷 기술로 떠오르고 있다.

  • PDF

Effect of Crosslinking on Release of Model Drug from Electrospun Poly(vinyl alcohol) Fiber Mats

  • Taepaiboon, Pattama;Rungsardthong, Uracha;Supaphol, Pitt
    • Proceedings of the Polymer Society of Korea Conference
    • /
    • 2006.10a
    • /
    • pp.258-258
    • /
    • 2006
  • Electrospun fibers of poly(vinyl alcohol) (PVA) were successfully prepared and applied as drug carriers for transdermal drug delivery system. Sodium Salicylate (SS) was the model drug and it was incorporated in the PVA fibers by adding 20 % of SS in a PVA solution prior to electrospinning. Electrospinning of SS-containing PVA solution resulted in the formation of beaded fibers. In order to control the rate of SS release and decrease water solubility of PVA, the SS-loaded electrospun PVA mat was cross-linked by either glutaraldehyde or glyoxal vapor. The morphology, thermal behavior, swelling behavior, release characteristic, kinetics of drug release and also toxicity of the cross-linked sample were investigated.

  • PDF

Effect of H-Y Antibody on in vitro Development of Mouse Embryos (H-Y항체의 처리가 생쥐수정란의 발달에 미치는 영향)

  • 고정재;심호섭;김종배;박홍양;정길생;이경광
    • Korean Journal of Animal Reproduction
    • /
    • v.10 no.1
    • /
    • pp.42-48
    • /
    • 1986
  • These experiments were carried out to develop new techniques identifying XX-bearing embryos prior to implantation by immunological method. Antiserum to histocompatibility-Y(H-Y) antigen was prepared in adult SD(sprague-dawley) female rat by repeated immunization of newbone testis supernatant from males of the same strain. ELISA test was used to identify the H-Y antibody of antiserum. Total 124 mouse embryos (8-cell stage) were treated with H-Y antiserum and complement in BSA free Ho, pp. and Pitt's medium and cultured under the gas phase of 5% CO2 in air at 37$^{\circ}C$ for 24 to 48 hrs. The morphological characteristics of embryos treated were observed under the phase-contrast micro scope. The results obtained in these experiments were summarized as follows: 1. Optimal Density of H-Y antibody were a, pp.ared to be 0.27-0.47 by ELISA test. 2. Of total 124 embryos treated with H-Y antiserum and complement 69(55.6%) embryos developed to blastocyst and 55(44.4%) destroyed or arrested.

  • PDF

Partitioning Interwell Tracer Test and Analysis Method for Estimating Oil Pollutants in the Underground (지중 유류오염량 추정을 위한 분배추적자 시험 및 해석방법)

  • Jeong, Chan-Duck;Kim, Yong-Cheol;Myeong, Woo-Ho;Bang, Sung-Su;Lee, Gyu-Sang;Song, Sung-Ho
    • Journal of Soil and Groundwater Environment
    • /
    • v.27 no.spc
    • /
    • pp.99-112
    • /
    • 2022
  • From early 2000, many researchers in the groundwater and soil environment remediation project tried to calculate the pollution level and pollution remediation cost and reflect it in the design. In addition, by identifying the movement characteristics of oil pollutants in the underground environment, many researchers tried to derive design factors necessary for pollution purification. However, although the test should be conducted in an area contaminated with oil, the toxicity and risk are too great for testing by deliberately leaking pollutants that are harmful to the human body. And as oil-contaminated areas are promoted by military units such as returned US military bases, there is a limit to access by the general public. In addition, since the indoor simulation test and the field application test have been carried out separately from each other, it was difficult to compare and review various simulation tests Therefore, in this study, PITT (Partitioning Interwell Tracer Test) and analysis methods were specifically presented through actual tests so that field workers could easily use them with the help of the military base and the Korea Rural Community Corporation Soil Environment Restoration Team. However, in order to directly reflect the distribution tracer test results in the pollution remediation design, it is necessary to reduce the analysis errors by comparing the analysis results of the existing soil pollution survey, physical exploration, and numerical modeling. In addition, it is judged to be cautious in the analysis because errors can easily occur due to various factors such as the type of oil at the polluted site, the hydraulic conductivity of the aquifer, and the skill of the researcher.