Photoproduction of the_f1(1285)meson

Dickson, R.,Schumacher, R. A.,Adhikari, K. P.,Akbar, Z.,Amaryan, M. J.,Anefalos Pereira, S.,Badui, R. A.,Ball, J.,Battaglieri, M.,Batourine, V.,Bedlinskiy, I.,Biselli, A.,Boiarinov, S.,Briscoe, W. J. American Physical Society 2016 Physical Review C Vol.93 No.6

<P>The f(1)(1285) meson withmass 1281.0 +/- 0.8MeV/c(2) and width 18.4 +/- 1.4MeV (full width at half maximum) was measured for the first time in photoproduction from a proton target using CLAS at Jefferson Lab. Differential cross sections were obtained via the eta pi(+)pi(-), K+(K) over bar (0) pi(-), and (K-K0)pi(+) decay channels from threshold up to a center-of-mass energy of 2.8 GeV. The mass, width, and an amplitude analysis of the eta pi(+)pi(-) final-state Dalitz distribution are consistent with the axial-vector J(P) = 1(+) f(1)(1285) identity, rather than the pseudoscalar 0(-) eta(1295). The production mechanism is more consistent with s-channel decay of a high-mass N* state and not with t-channel meson exchange. Decays to eta pi pi go dominantly via the intermediate a(0)(+/-) (980)pi(-/+) states, with the branching ratio Gamma [a(0)pi (no (K) over barK)]/Gamma[eta pi pi (all)] = 0.74 +/- 0.09. The branching ratios Gamma (K (K) over bar pi)/Gamma(eta pi pi) = 0.216 +/- 0.033 and Gamma (gamma rho(0))/Gamma(eta pi pi) = 0.047 +/- 0.018 were also obtained. The first is in agreement with previous data for the f(1)(1285), while the latter is lower than the world average.</P>

디스크소스로부터 NAPL의 확산손실에 관한 수학적 모델

윤인택,Dickson S. E 한국지하수토양환경학회 2008 지하수토양환경 Vol.13 No.6

Matrix diffusion from planar fractures was studied mathematically and through physical model experiments. Mathematical models were developed to simulate diffusion from 2D and 3D instantaneous disk sources and a 3 D continuous disk source. The models were based on analytical solutions previously developed by Carslaw and Jaeger (1959). The mathematical simulations indicated that the 2D scenario produces significantly different results from the 3D scenario, the time for mass disappearance is significantly larger for continuous sources than for instantaneous sources, the normalized concentration generally decreased over time for instantaneous sources while it increased over time for continuous sources, diffusion rates decrease significantly over time and space, and the normalized mass loss from the source zone never reaches 1 for continuous sources due to the semi-infinite integral. The simulations also showed that disappearance times increase exponentially with increasing source radii and matrix porosity, and decrease with increasing aqueous-phase NAPL solubilities. 평평한 fractures에서 공극을 가진 모암으로의 NAPL 확산을 수치적인 방법으로 해석하였다. 2D와 3D에 대한 일회 성 디스크 소스와 3D 연속 디스크소스에 대한 모델은 Caralaw and Jaeger(1959)의 이론을 바탕으로 개발하였다. 3D 연속 디스크소스에 대해 공극모암으로 확산되는 NAPL의 총량을 계산할 수 없기 때문에 확산이 반구형으로 이루어 진다고 가정하여 등농도선의 합을 이용하여 공극모암으로 확산되는 NAPL의 총량을 계산하였다. 수치적 계산에 따 르면 2D 대비 3D의 경우에 NAPL 손실 시간이 현저히 빠른 것으로 나타났으며, 디스크 소스의 중심점에서 normalized된 농도는 일회성 디스크 소스는 시간에 따라 감소하고, 연속 디스크 소스는 증가하는 것으로 나타났으며, 시간과 공간에 따라 확산율은 감소하는 것으로 나타났다. 그리고 NAPL의 mass 손실은 1에 도달하지 못하였으며, 이 는 연속 디스크 소스를 semi-infinite로 가정하고 적분했기 때문이다. 확산에 의해 사라지는 시간은 소스의 크기 및 모암 공극률 크기 증가에 비례해서 지수함수적으로 증가하고, 반면 NAPL의 용해성이 증가하면 감소하는 것으로 나 타났다.

Mathematical Models on Diffusive Loss of Non-Aqueous Phase Organic Solvents from a Disk Source

Yoon, In-Taek,S.E., Dickson Korean Society of Soil and Groundwater Environment 2008 지하수토양환경 Vol.13 No.6

평평한 fractures에서 공극을 가진 모암으로의 NAPL 확산을 수치적인 방법으로 해석하였다. 2D와 3D에 대한 일회성 디스크 소스와 3D 연속 디스크소스에 대한 모델은 Caralaw and Jaeger(1959)의 이론을 바탕으로 개발하였다. 3D 연속 디스크소스에 대해 공극모암으로 확산되는 NAPL의 총량을 계산할 수 없기 때문에 확산이 반구형으로 이루어진다고 가정하여 등농도선의 합을 이용하여 공극모암으로 확산되는 NAPL의 총량을 계산하였다. 수치적 계산에 따르면 2D 대비 3D의 경우에 NAPL 손실 시간이 현저히 빠른 것으로 나타났으며, 디스크 소스의 중심점에서 normalized된 농도는 일회성 디스크 소스는 시간에 따라 감소하고, 연속 디스크 소스는 증가하는 것으로 나타났으며, 시간과 공간에 따라 확산율은 감소하는 것으로 나타났다. 그리고 NAPL의 mass 손실은 1에 도달하지 못하였으며, 이는 연속 디스크 소스를 semi-infinite로 가정하고 적분했기 때문이다. 확산에 의해 사라지는 시간은 소스의 크기 및 모암 공극률 크기 증가에 비례해서 지수함수적으로 증가하고, 반면 NAPL의 용해성이 증가하면 감소하는 것으로 나타났다. Matrix diffusion from planar fractures was studied mathematically and through physical model experiments. Mathematical models were developed to simulate diffusion from 2D and 3D instantaneous disk sources and a 3D continuous disk source. The models were based on analytical solutions previously developed by Carslaw and Jaeger (1959). The mathematical simulations indicated that the 2D scenario produces significantly different results from the 3D scenario, the time for mass disappearance is significantly larger for continuous sources than for instantaneous sources, the normalized concentration generally decreased over time for instantaneous sources while it increased over time for continuous sources, diffusion rates decrease significantly over time and space, and the normalized mass loss from the source zone never reaches 1 for continuous sources due to the semi-infinite integral. The simulations also showed that disappearance times increase exponentially with increasing source radii and matrix porosity, and decrease with increasing aqueous-phase NAPL solubilities.

Completely V-regular algebra on semiring and its application in edge detection

George E. Chatzarakis,S. Dickson,S. Padmasekaran,J. Ravi 한국전산응용수학회 2023 Journal of applied mathematics & informatics Vol.41 No.3

In this paper, Completely V-Regular on semiring is defined and used to derive new theorems with some of its properties. This paper also illustrates V-Regular algebra and Completely V-Regular Algebra with examples and properties. By extending completely V-Regular to fuzzy, a new concept, fuzzy V-Regular is brought out and fuzzy completely V-Regular algebra is introduced too. It is also developed by defining the ideals of Completely V -Regular Algebra and fuzzy completely V-Regular algebra. Finally, this fuzzy algebra concept is applied in image processing to detect edges. This V-Regular Algebra is novel in the research area.

Biominerization of Iron : Mo¨ssbauer spectroscopy and Electron Microscopy of Ferrtin Cores from theChiton Acanthopleura hirtosa and the Limpet patella laticostata. Mo¨ssbauer spectroscopy와 전자 현미경을 이용한 Ferritin Core의 연구

Pierre, T.G.,Kim, K.S.st.,Webb, J.,Mann, S.,Dickson, D.P.E. 全北大學校 基礎科學硏究所 1991 基礎科學 Vol.14 No.2

Ferritins isolated from the hemolymph of the chiton Acanthopleura hirtosa and the limpet Patella laticostata have been studied by ^57Fe Mossbauer spectroscopy, electron diffraction, transmission electron microscopy (TEM), and inductively coupled plasma(ICP) spectrometry. Mossbauer spectra of the samples at 78 K were quadrupole-split doublets with similar quadrupole splittings and chemical isomer shifts, characteristic of octahedral high-spin iron(III), while at 4.2K the spectra were magnetically split sextests. The spectra yield mean superparamagnetic blocking temperatures of about 32 and 30 K for the A. hirtosa and P. laticostata ferritins, respectively, and indicate magnetic ordering temperatures of about 37 and 34 K. Core size distributions were measured for both the A. hirtosa and P. laticostata ferritins by using TEM and gave mean core size ranges of 8.0-8.5 and 7.5-8.0 nm, respectively. Diffuse lines in the electron diffraction patterns of the ferritin cores indicated the presence of ferrihydrite(5Fe_2-O_3·9H_2O) of limited crystallinity. Phosphorus to iron atomic ratios were measured by ICP spectrometry. The phosphorus levels were close to the limit of detection, giving approximate mean values of D:Fe of 1:44 for the P. laticostata ferritin and 1:36 for the A. hirtosa ferritin. These levels of phosphate are significantly less than those for the crystalline cores of mammalian ferritins and considerably less than those for the noncrystalline core of bacterioferritins.

A mechanistic study of in situ chemical cleaning-in-place for a PTFE flat sheet membrane: fouling mitigation and membrane characterization

Lee, Eui-Jong,An, Alicia K. J.,Hadi, Pejman,Yan, Dickson Y. S.,Kim, Hyung-Sook Taylor Francis 2016 Biofouling Vol.32 No.3

<P>This study aimed at unfolding the role and mechanisms of chemically enhanced cleaning-in-place (CIP) regimes in fouling control of polytetrafluoroethylene (PTFE) made flat sheet (FS) membrane bio-reactors (MBRs). The trans-membrane pressure (TMP) was successfully maintained below 10 kPa using a daily CIP regime consisting of 100 to 600 mg l(-1) of NaOCl and cake layer resistance control was shown to be critical for effective high-flux MBR operation. In contrast, in the control unit without the CIP, the TMP exceeded 35 kPa at a flux of 40 LMH. The extracellular polymeric substances associated with proteins (EPSprotein) were also controlled effectively with a daily application of the CIP to the fouled membrane. Moreover, the CIP prompted a thinner and looser bio-cake layer on the membrane surface, suggesting that in situ CIP can be a favorable method to control FS membrane fouling at high-flux MBR operation.</P>