Sheffield艦의 衝擊

Stanfield Turner,박홍식 해군대학 1982 海洋戰略 Vol.- No.16

1. 취약성 셰필드함이 우리에게 준 교훈은 다음과 같다. GUSWOrk지는 어떠한 대안도 찾을 수가 없기 때문에 비록 항공모함, 상륙기습함정 및 구축함 등의 수상함정이 취약하다고는 하더라도 이들 함정을 퇴역시킬 수는 없다. 대신에 우리는 이러한 취약성 때문에 우리가 어떠한 설계를 해야하고 어떻게 이들을 운용해야 하는가에 대해 검토해 보아야 한다. 2. 무기평가 미래의 수상함들은 오늘날의 것보다 더욱 대형이며 보다 복잡한 형태의 것이어서는 안 되며, 새로운 공학을 이용한 함정들이어야 한다는 것이다. 또한 우리의 해군력을 분산시키고, 특히 그 항공세력을 보다 많은 그리고 소형의 플랫폼으로 분산시키도록 만드는 계기가 되어야 한다는 것이다.

Mechanistic Possibilities for Non-Precious Metal/Nitrogen Doped Carbons As Catalysts for the Oxygen Reduction Reaction

( Stanfield Youngwon Lee ),( Christoper W. Bielawski ),정동영,강윤식,이명재,성영은 한국공업화학회 2014 한국공업화학회 연구논문 초록집 Vol.2014 No.0

Unraveling the oxygen reduction reaction active sites for non-precious metal catalysts in alkaline mediums

( Stanfield Youngwon Lee ),( Christopher Bielawski ),정동영,강윤식,이명재,신희종,김미주,성영은 한국공업화학회 2014 한국공업화학회 연구논문 초록집 Vol.2014 No.1

Our work focused on determining if this outer Helmholtz plane reaction does indeedexist and play a significant role in non-precious metal catalysts. A three electrode half-cell was used tomeasure the oxygen reduction reaction activity of a non-precious metal catalystin different alkaline electrolytes. Using electrolytes with different cations altered the hydration energyas well as block or increase access of oxygen to the outer Helmholtzplane. Correlations between hydrationshell size and catalytic activity were observed.

突發事態에 對한 對備策

Stanfield Turner 해군대학 1983 海洋戰略 Vol.- No.26

Komer 대사와 같은 사람들이 실제로 분명한 관심을 두고 있는 것은 다음과 같은 사실이다. 즉. 해양통제 및 상륙 투입수단 그리고 좀더 기동성 있는 증원 지상군 및 공군 등에 관한 이 세가지 방편들로 인해서 미구근 더 이상 유럽안보에 관심을 기울이지 않는다는 사실을 이지역 동맹국들로 하여금 인식하게끔 하든가, 아니면 이지역에 있는 많은 미 자원을 철수시켜 거의용남하기 어려울 정도로 미국의공헌도를 약화시킴으로서 결과적으로 유럽지역에 있어서의 미국의 준비태세를 감소시킬 것이라는 사실인 것이다. 그러나 이들중 어느것도 실제 사례가 될 필요는 없는 것이다. 동맹국들오 하여금 더욱 가증된 방위부담을 지도록 하는 방책은 사실상 용이하지 않을 것이다. 하지만 유럽의 영속적인 연함전략에 있어서도 거의 비슷한 문제점에 직면해 있다. Komer대사가 동맹국들에게 요구하는 것은 공동방위전략에 보다 더 많은 기여를 하고 국가 주의적 사고력식을 억제함으로써 무기조달에 자금을 공동으로 출자하여 예산을 절감토록 한다는 것이다. 하지만 이런 목표들은 지난 수년 동안에 걸쳐서 아무런 보람도 없이 동맹국들에게 강요되어 왔다. 오늘날 연합전략가들이 이 목표에 대해 동맹국들에게 자극을 가해 더욱 성공적인 성과를 거둘 것이라고 생각하기에는 사실상 아무런 확실한 근거가 없는 것이다. 지난 32년 동안에 걸쳐서 NATO는 바르샤바(Warsaw) 조약기구보다 더욱 증대된 경제적 능력과 인구의 증가를 가져왔다. 그러나 군비면에 있어서는 불균형할 만큼 많은 미국의 지원에도 불구하고 점차적으로 열세에 놓여지고 있는 것이다. 미국이 적어도 어떤식으로든지 현재와 마찬가지로 방위부담을 질 것이라고 동맹국들이 계속해서 신뢰하고 있는 한 그들에게서 지금보다 더 많은 것을 기대하기는 어려울 것이다. 미국은 앞서 제시한 방식으로서 해양전략을 갈수록 변환시킬 것이라는 의도를 공표함으로써 유럽인들로 하여금 더욱 진지하게 자신들의 방위책임을 맡도록 자극을 불어 넣을 수 있을 것이다. 확실히 유럽에 있어 중동으로부터의 오일(Oil)공급의 중단은 치명적인 위협이 되고 있는 것이다. 미국이 중동에 대해 동맹관계로서의 군사적 책임을 담당하게 됨으로써 중동도 유럽에 대해 미국의 지원에 부합될 수 있는 일련의 조치를 취하는 것이 바람직할 것이다. 만일 중동이 이러한 상황하에서 별다를 조치를 취하려 하지 않는다면 미국은 다른 어떠한 방책을 가지고도 중동으로 하여금 미국의 의도에 부합되는 조치를 취하게끔 설득할 수가 없는 것이다.

Charting the Outer Helmholtz Plane and the Role of Nitrogen Doping in the Oxygen Reduction Reaction Conducted in Alkaline Media Using Nonprecious Metal Catalysts

Lee, Stanfield Youngwon,Chung, Dong Young,Lee, Myeong Jae,Kang, Yun Sik,Shin, Heejong,Kim, Mi-Ju,Bielawski, Christopher W.,Sung, Yung-Eun American Chemical Society 2016 The Journal of Physical Chemistry Part C Vol.120 No.43

<P>This study was focused On elucidating the origin of the catalytic activity displayed by non-precious-metal-based, oxygen reduction reaction (ORR) catalysts before and after heat treatment. Electrochemical measurements were recorded using a series of metal phthalocyanines calculated to exhibit varying oxygen adsorption energies before and after heat treatment at a temperature Sufficiently high to facilitate degradation. Collectively, the results indicate that while the oxygen adsorption is germane to the catalytic activity before heat, treatment, the ORR appears to proceed through. a different pathway that is not dependent on adsorption energy after heat treatment. These conclusions help to explain the high catalytic activities exhibited by carbon- or nitrogen-based materials containing metal ions after heat treatment and may lead to the realization of substitutes for ORB. catalysts that utilize precious transition metals.</P>

Ascertaining the Carbon Hybridization States of Synthetic Polymers with X-ray Induced Auger Electron Spectroscopy

Lee, Stanfield Y.,Lyu, Jihong,Kang, Songsu,Lu, Sherilyn Jiawen,Bielawski, Christopher W. American Chemical Society 2018 The Journal of Physical Chemistry Part C Vol.122 No.22

<P>X-ray induced Auger electron spectroscopy was used to evaluate synthetic polymers containing carbons with differing degrees of sp-, sp<SUP>2</SUP>-, and sp<SUP>3</SUP>-hybridization states as well as heteroatoms. For comparison, a series of related small molecules was also studied. Linear correlations were observed and a universal calibration method for quantifying the average hybridization states of a wide variety of synthetic polymeric materials is offered.</P> [FIG OMISSION]</BR>

The Substates with Mutants That Negatively Charged Aspartate in Position 172 Was Replaced with Positive Charge in Murine Inward Rectifier Potassium Channel (Murine Kir2.1)

So, I.,Ashmole, I.,Stanfield, P.R. The Korean Society of Pharmacology 2003 The Korean Journal of Physiology & Pharmacology Vol.7 No.5

We have investigated the effect on inducing substate(s) of positively charged residues replaced in position 172 of the second transmembrane domain in murine inward rectifier potassium channels, formed by stable or transient transfection of Kir2.1 gene in MEL or CHO cells. Single channel recordings were obtained from either cell-attached patches or inside-out patches excised into solution containing 10 mM EDTA to rule out the effect of $Mg^{2+}$ on the channel gating. The substate(s) could be recorded with all mutants D172H, D172K and D172R. The unitary current-voltage (I-V) relation was not linear with D172H at $pH_i$ 6.3, whereas the unitary I-V relation was linear at $pH_i$ 8.0. The relative occupancy at $S_{LC}$ was increased from 0.018 at $pH_i$ 8.0 to 0.45 at $pH_i$ 5.5. In H-N dimer, that was increased from 0.016 at $pH_i$ 8.0 to 0.23 at $pH_i$ 5.5. The larger the size of the side chain or $pK_a$ with mutants (D172H, D172K and D172R), the more frequent the transitions between the fully open state and substate within an opening. The conductance of the substate also depended upon the pKa or the size of the side chain. The relative occupancy at substate $S_{LC}$ with monomer D172K (0.50) was less than that in K-H dimer (0.83). However, the relative occupancy at substate with D172R (0.79) was similar to that with R-N dimer (0.82). In the contrary to ROMK1, positive charge as well as negative charge in position 172 can induce the substate rather than block the pore in murine Kir2.1. The single channel properties of the mutant, that is, unitary I-V relation, the voltage dependence of the mean open time and relative occupancy of the substates and the increased latency to the first opening, explain the intrinsic gating observed in whole cell recordings.

Improving the catalytic activity of carbon supported platinum-cobalt nanoparticle for the oxygen reduction reaction via post treatment surface modifications

김미주,강윤식,이명재,( Stanfield Youngwon Lee ),신희종,성영은 한국공업화학회 2014 한국공업화학회 연구논문 초록집 Vol.2014 No.1

Polymer electrolyte membrane fuel cells (PEMFC) are a sort of electrochemical devices that exerts the conversion of chemical energy into electrical energy under low operating temperatures. Due to the sluggish oxygen reduction reaction (ORR) in PEMFC, oxygen electrode catalysts that lower the overpotential are of significant importance. To reduce the usage of Pt, well known to be the best ORR catalyst but extremely expensive, research continues to be done to develop Pt-based catalysts that have been treated to create a Pt enriched surface. Herein we synthesized carbon supported Platinum-Cobalt nanoparticles and conducted acid and heat treatments to provide evidence of improved ORR activity due to a Pt rich surface structure. Physical and electrochemical characterizations were determined using tools such as X-ray diffraction, cyclic voltammetry (CV), and X-ray photoelectron spectroscopy (XPS).

Unveiling a Masked Polymer of Dewar Benzene Reveals <i>trans</i>-Poly(acetylene)

Seo, Jinwon,Lee, Stanfield Y.,Bielawski, Christopher W. American Chemical Society 2019 Macromolecules Vol.52 No.8

<P>A dibromo derivative of Dewar benzene, <I>trans</I>-5,6-dibromobicyclo[2.2.0]hex-1-ene, was polymerized using ring-opening metathesis polymerization (ROMP). The reaction proceeded in a controlled manner as changing the initial monomer-to-catalyst ratio afforded monodispersed polymers with tunable molecular weights and growing polymer chains were extended upon subsequent exposure to additional monomer. Treatment of the halogenated polymers with an alkyllithium reagent resulted in elimination followed by isomerization to afford <I>trans</I>-poly(acetylene). Based on a series of mechanistic and spectroscopic studies, the transformation was proposed to proceed through a cyclobutenyl intermediate that undergoes rearrangement. The methodology was found to be versatile as triblock copolymers containing the halogenated homopolymer were prepared and converted to their poly(acetylene)-containing derivatives. The polymers were characterized using gel permeation chromatography as well as a range of spectroscopic (NMR, FT-IR, UV-vis, and Raman) and analytical techniques.</P> [FIG OMISSION]</BR>

The synthesis and evaluation of Pt@IrCo/C for bifunctional electrocatalysts for oxygen reduction reaction and oxygen evolution reaction

이명재,강윤식,정동영,( Stanfield Lee ),성영은 한국공업화학회 2014 한국공업화학회 연구논문 초록집 Vol.2014 No.1

A fuel cell is an electrochemical energy conversion device that functions by harnessing the chemical energy released from chemical reactions occurring at the anode and cathode and converting it into electrical energy. Currently, ways to reduce or eliminate the use of platinum in fuel cells remain a popular area of research because the high cost of platinum is preventing commercialization. Also, electrolyzing mode of PEMFC to electrically dissociate water to fuel has been required for unitized regenerative fuel cell (URFC) for use in spaceships or satellites. Our work focused on enhancing the activity of platinum used by creating a platinum shell on iridium-cobalt alloyed core. The decision to use iridium-cobalt alloyed core was used instead of conventional metal core supports was made with the idea that too strong interaction between platinum and iridium may be altered by iridium-cobalt core, improving its oxygen reduction activity and oxygen evolution activity.