Rhodopseudomonas sphaeroides 고정화균체의 자동조절 옥외 반연속배양에 의한 수소생산

김진상,배무 이화여자대학교 생명과학연구소 1992 생명과학연구논문집 Vol.3 No.-

광합성세균에 의한 광의존 수소생산에 있어서 상시 가변적인 태양광 이용조건에 대응되는 자동조절 반연속배양장치를 구성하였다. 이는 pulse 발생장치를 설비한 가스메터에 의해 일정의 수소생산량이 측정되면, 수소생산에 소비된 만큼의 기질이 timer와 연결된 정량펌프에 의해 공급될 수 있는 시스템이다. 이 배양장치를 이용하여, 옥외조건에서 Rhodopseudomanas sphaeroides B6의 agar gel 고정화균체에 의한 수소생산 실험을 시도하였다. 일조와 기후의 격심한 변동에도 불구하고 배양이 잘 조절되어 수소생산성이 유지되었다. 이는 광합성세균의 수소생산을 위한 옥외반연속배양의 자동조절 가능성을 나타내는 것이다. For the photoproduction of molecular hydrogen by photosynthetic bacteria in outdoor conditions, we constructed automatically controlled semi-continuous culture system. When the amout of hydrogen gas produced can be measured by a gas meter with a pulse generator, the same amout of substrate consumed for hydrogen production could be supplied by micropump related with timers. Using the apparatus, we examined hydrogen production with immobilized cells of Rhodopseudomanas sphaeroides B6 in outdoor conditions. In spite of severe fluctuation of weather and illumnination, the culture was maintained under good control with regard to hydrogen productivity. It was possible to automate the semi-continuous outdoor culture of photosynthetic bacteria for hydrogen production.

Modeling the Small Dark Energy Scale with a Quintessential Pseudoscalar Boson

Jihn E. Kim 한국물리학회 2014 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.64 No.6

Democracy among the same type of particles is a useful paradigm in studying masses and interactionsof particles with supersymmetry (SUSY) or without SUSY. This simple idea predicts thepresence of massless particles. We attempt to use one of these massless pseudoscalar particles togenerate the cosmological dark energy (DE) potential. To achieve the extremely shallow potentialof DE, we require the pseudoscalar boson not couple to quantum chromodynamics (QCD) anomaly. Thus, we consider two pseudoscalars, one coupling to the QCD anomaly (i.e., the QCD axion) andthe other not coupling to the QCD anomaly. To obtain these two pseudoscalars, we introduce twoapproximate global U(1) symmetries to realize them as the pseudo-Goldstone bosons of the spontaneouslybroken U(1) symmetries. These global symmetries are dictated by a gravity-respectingdiscrete symmetry. Specifically, we consider an S2(L) × S2(R) × Z10R example and attempt toobtain the DE scale in terms of two observed fundamental mass scales, the grand unification scaleMG and the electroweak scale vew.

Final State Interaction Phases Obtained by Data from CP Asymmetries

Jihn E. Kim,남순건,모도영 한국물리학회 2015 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.66 No.6

Evidence of physics beyond the Standard Model (SM) of particle physics might be revealedthrough CP violation. Experimental results from BaBar, Belle, and most recently from LargeHadron Collider b-factory (LHCb) are very interesting in this respect. Calculating various CPviolation parameters within the SM is reported. In this letter, the final state interaction (FSI)phases with the CKM matrix are calculated by using the recent experimental results from LHCbon CP violation in B0and B0s meson decays. To obtain the allowed regions of the FSI phases, weused a simplified form of the Jarlskog determinant of the CKM matrix, and we found the CP phaseδ close to the maximal phase of π/2. Then, the asymmetry data on B0and B0s from LHCb wereused to explore graphically the allowed regions of the FSI phases.

Dark Matter and the Axion

Jihn E. Kim 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.53 No.6

Axions can compose dark matter in the universe. We review the essential properties of axion, some related theoretical issues and its astrophysical and cosmological searches. Axions can compose dark matter in the universe. We review the essential properties of axion, some related theoretical issues and its astrophysical and cosmological searches.

Recent trends in the synthesis of graphene and graphene oxide based nanomaterials for removal of heavy metals — A review

Jihn Yih Lim,N.M. Mubarak,E.C. Abdullah,Sabzoi Nizamuddin,Mohammad Khalid,Inamuddin 한국공업화학회 2018 Journal of Industrial and Engineering Chemistry Vol.66 No.-

The advanced synthesis and development of raw graphene based on various significant functionalization has been outstanding in the wastewater treatment compared to the other alternatives such as carbon nanotubes and other carbon nanomaterials. Nano size graphene is known to possess large surface area and some promising properties in terms of mechanical, electrical, chemical and magnetism. Besides, the graphene can be generated via both Top-down and Bottom-up methods such as chemical exfoliation, chemical vapour deposition and other techniques so that it can be further functionalized to form graphene oxide-based nanomaterials. Hence, graphene oxide-based nanomaterials are discovered to be useful in the application of heavy metal removal from wastewater. In short, this paper critically reviewed on the synthesis method of graphene and application of graphene oxide-based nanomaterials in the term of heavy metal removal. The advantages, drawbacks, comparison of the data efficiencies, and research requirements are further highlighted, elaborated and discussed detailly. Lastly, the future challenges of graphene are elaborated. Therefore, it can be guaranteed that the wastewater discharged should be detected with the minimum or none of the heavy metals so that minimum effects on the ecosystem is discovered.

Brane gravity, massless bulk scalar, and self-tuning of the cosmological constant

Kim, Jihn E.,Kyae, Bumseok,Shafi, Qaisar American Physical Society 2004 PHYSICAL REVIEW D - Vol.70 No.6

Unifying CP violations of quark and lepton sectors

Kim, Jihn E.,Nam, Soonkeon Springer-Verlag 2015 European Physical Journal C Vol.75 No.12

Gauges in the bulk

Kim, Jihn E.,Tupper, Gary B.,Viollier, Raoul D. Elsevier 2004 Physics letters: B Vol.593 No.1

<P><B>Abstract</B></P><P>We present a general framework for nonparallel brane worlds and use it to discuss the nonlinear radion problem. By imposing the Einstein frame as a gauge condition we are able to give the effective action for both Minkowski and (A)dS<SUB>4</SUB> branes. In particular, we find the nonlinear radion does not disappear in the second Randall–Sundrum model.</P>

On the Progenitor Quark Mass Matrix

Kim Jihn E.,Kim Se-Jin 한국물리학회 2020 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.77 No.1

We determined the quark mass matrix in terms of a small expansion parameter ${\sqrt{\varepsilon}}$, which gives correctly all the quark masses and the Cabibbo-Kobayashi-Maskawa (CKM) matrix elements on the electroweak (EW) scale, and we obtained a progenitor form at the grand unified theory (GUT) scale by running the EW scale mass matrix. Finally, a possible texture form for the progenitor quark mass matrix is suggested.

“Invisible” QCD axion rolling through the QCD phase transition

Kim, Jihn E.,Kim, Se-Jin North-Holland Pub. Co 2018 Physics letters. Section B Vol.783 No.-

<P><B>Abstract</B></P> <P>Visible matter in the current Universe is a consequence of the phase transition of the strong force, quantum chromodynamics (QCD). This phase transition has occurred at the Universe temperature around <SUB> T c </SUB> ≃ 165 MeV while it was expanding. Strongly interacting matter particles are quarks above <SUB> T c </SUB> , while they are pions, protons and neutrons below <SUB> T c </SUB> . The spin degrees of freedom 37 (<I>u</I> and <I>d</I> quarks and gluons) just above <SUB> T c </SUB> are converted to 3 (pions) after the phase transition. This phase transition might have been achieved mostly at supercooled temperatures. The supercooling was provided by the expansion of the Universe. We obtain the effective bubble formation rate α ( T ) ≈ <SUP> 10 4 − 5 </SUP> MeV and the completion temperature of the phase change (to the hadronic phase), <SUB> T f </SUB> ≃ 126 MeV . During the phase transition, the scale factor <I>R</I> has increased by a factor of 2.4. This provides a key knowledge on the energy density of “invisible” QCD axion at the full hadronic-phase commencement temperature <SUB> T f </SUB> , and allows for us to estimate the current energy density of cold dark matter composed of “invisible” QCD axions.</P>