Simulation of single grid-based phase-contrast x-ray imaging (g-PCXI)

Lim, H.W.,Lee, H.W.,Cho, H.S.,Je, U.K.,Park, C.K.,Kim, K.S.,Kim, G.A.,Park, S.Y.,Lee, D.Y.,Park, Y.O.,Woo, T.H.,Lee, S.H.,Chung, W.H.,Kim, J.W.,Kim, J.G. Elsevier BV * North-Holland 2017 Nuclear Instruments & Methods in Physics Research. Vol. No.

<P><B>Abstract</B></P> <P>Single grid-based phase-contrast x-ray imaging (g-PCXI) technique, which was recently proposed by Wen et al. to retrieve absorption, scattering, and phase-gradient images from the raw image of the examined object, seems a practical method for phase-contrast imaging with great simplicity and minimal requirements on the setup alignment. In this work, we developed a useful simulation platform for g-PCXI and performed a simulation to demonstrate its viability. We also established a table-top setup for g-PCXI which consists of a focused-linear grid (200-lines/in strip density), an x-ray tube (100-μm focal spot size), and a flat-panel detector (48-μm pixel size) and performed a preliminary experiment with some samples to show the performance of the simulation platform. We successfully obtained phase-contrast x-ray images of much enhanced contrast from both the simulation and experiment and the simulated contract seemed similar to the experimental contrast, which shows the performance of the developed simulation platform. We expect that the simulation platform will be useful for designing an optimal g-PCXI system.</P> <P><B>Highlights</B></P> <P> <UL> <LI> It is proposed for the single grid-based phase-contrast x-ray imaging (g-PCXI) technique. </LI> <LI> We implemented for a numerical simulation code. </LI> <LI> The preliminary experiment with several samples to compare is performed. </LI> <LI> It is expected to be useful to design an optimal g-PCXI system. </LI> </UL> </P>

Effect of Curing Time on the Physicochemical and Sensory Properties of Beef Jerky Replaced Salt with Soy Sauce, Red Pepper Paste and Soybean Paste

Lim, H.J.,Kim, G.D.,Jung, E.Y.,Seo, H.W.,Joo, S.T.,Jin, S.K.,Yang, H.S. Asian Australasian Association of Animal Productio 2014 Animal Bioscience Vol.27 No.8

This study was done to investigate the quality properties of beef jerky with soy sauce, red pepper paste, and soybean paste replacing salt. Sliced beef samples were cured in salt (control), soy sauce, red pepper paste, and soybean paste for 24 or 48 h and then dried at $70^{\circ}C$ for 8 h. Treatments showed higher final moisture content and lower $Na^+$ concentration than the control after drying for 8 h. The lightness and shear force values were lower in all treatment samples than in the control during 48 h of curing time. In particular, lower lipid oxidation was found in the jerky cured with red pepper paste than in the control. Sensory evaluation showed that color, flavor, and tenderness of jerky samples were improved by replacing salt with soy sauce, red pepper paste and soybean paste, and higher likeability scores of the beef jerky were obtained among those treatments after 48 h of curing time.

Nuclear magnetic resonance study of the phase transitions and local environments of α-alum NH₄Al(SO₄)₂.12H₂O single crystals

Lim, A.R.,Moon, H.G.,Chang, J.H. Elsevier Science Publishers [etc.] 2010 Chemical physics Vol.371 No.1

The NMR spectrum, the spin-lattice relaxation time, T<SUB>1</SUB>, and the spin-spin relaxation time, T<SUB>2</SUB>, of NH<SUB>4</SUB>Al(SO<SUB>4</SUB>)<SUB>2</SUB>.12H<SUB>2</SUB>O crystals were studied as a function of temperature; this crystal was found to undergo increasing loss of H<SUB>2</SUB>O with increasing temperature. Two groups of Al resonance lines were observed below T<SUB>d</SUB> (=335K), whereas above T<SUB>d</SUB> the resonance lines of the two groups were reduced to one Al signal. The presence of only one <SUP>27</SUP>Al resonance line T<SUB>d</SUB> is due to the structural phase transition. The changes in the temperature dependences of the T<SUB>1</SUB> and T<SUB>2</SUB> near T<SUB>d</SUB> are related to the loss of H<SUB>2</SUB>O, which probably disrupts the forms of the octahedral of water molecules surrounding Al<SUP>3+</SUP>. In addition, the α-alum NH<SUB>4</SUB>Al(SO<SUB>4</SUB>)<SUB>2</SUB>.12H<SUB>2</SUB>O can be distinguished from the α-alum RbAl(SO<SUB>4</SUB>)<SUB>2</SUB>.12H<SUB>2</SUB>O and the β-alum CsAl(SO<SUB>4</SUB>)<SUB>2</SUB>.12H<SUB>2</SUB>O on the basis of the temperature dependences of T<SUB>1</SUB>.

Two zinc-aminoclays' in-vitro cytotoxicity assessment in HeLa cells and in-vivo embryotoxicity assay in zebrafish

Chun, H.S.,Park, D.,Eun Lim, S.,Jeong, K.H.,Park, J.S.,Park, H.J.,Kang, S.,Kang, K.S.,Park, H.G.,An, H.R.,Huh, Y.S.,Lee, Y.C. Academic Press 2017 Ecotoxicology and environmental safety Vol.137 No.-

<P>Two zinc-aminoclays [ZnACs] with functionalized primary amines [(-CH2)(3)NH2] were prepared by a simple solgel reaction using cationic metal precursors of ZnCl2 and Zn(NO3)(2) with 3-aminopropyl triethoxysilane [APTES] under ambient conditions. Due to the facile interaction of heavy metals with primary amine sites and Zn-related intrinsic antimicrobial activity, toxicity assays of ZnACs nanoparticles (NPs) prior to their environmental and human-health applications are essential. However, such reports remain rare. Thus, in the present study, a cell viability assay of in-vitro HeLa cells comparing ZnCl2, Zn(NO3)(2) salts, and ZnO (similar to 50 mn average diameter) NPs was performed. Interestingly, compared with the ZnCl2, and Zn(NO3)(2) salts, and ZnO NPs (18.73/18.12/ 51.49 mu g/mL and 18.12/15.19/46.10 mu g/mL of IC50 values for 24 and 48 h), the two ZnACs NPs exhibited the highest toxicity (1050 values of 21.18/18.36 mu g/mL and 18.37/17.09 mu g/mL for 24 and 48 h, respectively), whose concentrations were calculated on Zn elemental composition. This might be due to the enhanced bioavailability and uptake into cells of ZnAC NPs themselves and their positively charged hydrophilicity by reactive oxygen species (ROS) generation, particularly as ZnACs exist in cationic NP's form, not in released Zn2+ ionic form (i.e., dissolved nanometal). However, in an in-vivo embryotoxicity assay in zebrafish, ZnACs and ZnO NPs showed toxic effects at 50-100 mu g/mL (corresponding to 37.88-75.76 of Zn wt% mu g/mL). The hatching rate (%) of zebrafish was lowest for the ZnO NPs, particularly where ZnAC-[(NO3)(2)] is slightly more toxic than ZnAC-[Cl-2]. These results are all very pertinent to the issue of ZnACs' potential applications in the environmental and biomedical fields.</P>

Effect of Anodic Gas Compositions on the Overpotential in a Molten Carbonate Fuel Cell

Lee C.G.,Kim D.H.,Hong S.W.,Park S.H.,Lim H.C. The Korean Electrochemical Society 2006 한국전기화학회지 Vol.9 No.2

Anodic overpotential has been investigated with gas composition changes in a $100cm^2$ class molten carbonate fuel cell. The overpotential was measured with steady state polarization, reactant gas addition (RA), inert gas step addition (ISA), and electrochemical impedance spectroscopy (EIS) methods at different anodic inlet gas compositions, i.e., $H_2:CO_2:H_2O=0.69:0.17:0.14\;atm\;and\;H_2:CO_2:H_2O=0.33:0.33:0.33\;atm$, at a fixed $H_2$ flow rate. The results demonstrate that the anodic overpotential decreases with increasing $CO_2\;and\;H_2O$ flow rates, indicating the anode reaction is a gas-phase mass-transfer control process of the reactant species, $H_2,\;CO_2,\;and\;H_2O$. It was also found that the mass-transfer resistance due to the $H_2$ species slightly increases at higher $CO_2\;and\;H_2O$ flow rates. EIS showed reduction of the lower frequency semi-circle with increasing $H_2O\;and\;CO_2$ flow rate without affecting the high frequency semi-circle.

Ratio Dependence of the Visible Light Photocatalytic Efficiency for Zn_2Ti_(0.9)Cr_yFe_([0.1]-y)O_4: Cr/Fe (0.02 < y < 0.08) Photocatalyst Synthesized by Using a Solid State Reaction Method

Pramod H. Borse,조채용,K. T. Lim,Y. J. Lee,배종성,정의덕,H. G. Kim 한국물리학회 2011 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.59 No.1

We synthesized four different photocatalyst systems viz. Zn_2TiO_4, Zn_2Ti_(1-x)Fe_xO_4, Zn_2Ti_(1-x)Cr_xO_4 (0 ≤ x < 0.8) and Zn_2Ti_(0.9)Cr_yFe_([0.1]-y)O_4 (0.022TiO<SUB>4</SUB> was converted to visible light active material by controlled doping/co-doping of Cr and Fe metal-ions at Ti substitutional site. We investigated their structural, optical and photocatalytic water decomposition property. The co-doping induces strong absorption bands in visible region (at λ~ 480 nm and λ~ 620 nm) in the host band gap. The optimum system of Zn_2Ti_(0.9)Cr_(0.05)Fe_(0.05)O_4 yielded maximum H<SUB>2</SUB> generation. In contrast to the visible light inactivity of Fe and Cr doped Zn_2TiO_4, the H_2 production under visible light irradiation from co-doped samples, increased till the optimum ‘y’ value. Consequently, there exists an optimized co-dopant concentration for efficient photocatalytic hydrogen production under visible light (λ ≥ 420 nm).

Modeling of Brain D2 Receptor Occupancy-Plasma Concentration Relationships with a Novel Antipsychotic, YKP1358, Using Serial PET Scans in Healthy Volunteers

Lim, K S,Kwon, J S,Jang, I-J,Jeong, J M,Lee, J S,Kim, H W,Kang, W J,Kim, J-R,Cho, J-Y,Kim, E,Yoo, S Y,Shin, S-G,Yu, K-S Springer Science and Business Media LLC 2007 Clinical pharmacology and therapeutics Vol.81 No.2

<P>YKP1358 is a novel serotonin (5-HT(2A)) and dopamine (D(2)) antagonist that, in preclinical studies, fits the general profile of an atypical antipsychotic. We conducted a D(2) receptor occupancy study with YKP1358 in healthy volunteers using positron emission tomography (PET) to measure the D(2) receptor occupancy of YKP1358 and to characterize its relationship to plasma drug concentrations. A single oral dose, parallel group, dose-escalation (100, 200, and 250 mg) study was performed in 10 healthy male volunteers with the PET radiotracer [(11)C]raclopride. The D(2) receptor occupancy of striatum was measured pre-dose, and at 2, 5, and 10 h after YKP1358 administration. Serial blood samples were taken for measurement of plasma YKP1358 concentrations. D(2) receptor occupancy by YKP1358 increased to 53-83% at 2 h, and then decreased afterwards, ranging from 40-64% at 5 h to 20-51% at 10 h. The YKP1358 dose-plasma concentration relationship exhibited extensive variability, but there was a good relationship between plasma concentrations and D(2) receptor occupancy that was well predicted by a sigmoid E(max) model using nonlinear mixed effects modeling. To our knowledge, this is the first study in which the relationship between plasma concentration and the biomarker of D(2) receptor occupancy was modeled using nonlinear mixed effects modeling. It is anticipated that these results will be useful in estimating for subsequent studies the initial doses of YKP1358 required to achieve a therapeutically effective range of D(2) receptor occupancy.</P>

On Pattern Classification of EMG Signals for Walking Motions

H,-L,Choi,H,-J,Byun,W,-G,Song,J,-W,Son,J,-T,Lim 한국과학기술원 인간친화 복지 로봇 시스템 연구센터 2001 International Journal of Assistive Robotics and Me Vol.2 No.3

  In this paper, we present a method to classify electromyogram (EMG) signals which are utilized to control signals for patient-responsive walker-supported system for paraplegics. Patterns of EMG signals for different walking motions are classified via adequate filtering, real EMG signal extraction, AR-modeling, and modified self-organizing feature map (MSOFM). In particular, a data-reducing extraction algorithm is employed for real EMG signals. Moreover, MSOFM classifies and determines the results automatically using a fixed map. Finally, the experimental results are presented for validation.

청초와 볏짚을 이용한 완전배합발효사료의 저장기간에 따른 화학조성분의 변화

이현준,김원호,김현섭,임근발,안병석,조광근,강승하,강상기,이홍구,우정희,최윤재 한국동물자원과학회 2002 한국축산학회지 Vol.44 No.6

Three kinds of green forages(rye, oats and mixed forages) was harvested and mixed with rice straw, wheat bran and 2 grains(corn and soybean), which harvested 2 different dates(common harvesting dates, 7 days early to common harvesting dates). And each mixture was ensiled in 6 poly vinyl chlorides that was 60 liter, immediately. They were opened at 0, 5, 10, 25, 35, 60 and 100 days after ensiling for chemical analysis. And its effects of those TMFFs on feed values were observed. Average contents of water, crude protein, ADF, NDF, Ca and P of formulated TMFs were 72 to 75%, 14.75 to 18.24, 12.47 to 19.07, 39.82 to 47.01, 0.99 to 1.07 and 0.38 to respectively. Crude protein content was the highest in the mixed forages-TMFF and the lowest in the rye-TMFF. The ADF and NDF contents of rye-TMFF were higher than others. And CP, ADF, NDF, TDN, P and Ca contents were no significant difference among treatments regardless of storage period and harvest time, but all treatments indicated good quality. Intenal temperatures of TMFF were shown to be 1 to 5℃ higher than ambient temperatures. The temperature of the Oat-TMFF formulated during winter sustained higher to the level of 6∼9℃ for 10 days. The pH of TMFF were 4.0 to 4.2 and the content of NH_3-N was shown to be 7.79 to 8.23㎎/㎗. In the VFA contents, any tendency was not shown at all treatments depending on harvest time. Even though rye-TMFF showed the lowest VFA value. At all treatments except rye-TMFF, propionate production was increased and stable after 25 days of storage. Digestibility of rice straw from TMFF on DM basis was 15∼20% higher compared with non-treated rice straw.

한국산 원유의 화학적 조성에 관한 연구 : 지역별 · 계절별

이현종,강국희,고준수,김영교,김영주,김종우,김현욱,박종래,유제현,윤여창,윤영호,임종우 제주대학교 농과대학 제주도축산문제연구소 1991 畜産論叢 Vol.6 No.1

Totally 881 bulked raw milk samples were collected once a month from Oct. 1989 to Sep. 1990 at 18 districts plus 8-16 farms in the all over Korea, and general composition of raw milk were analysed for the variation and correlation in between provincial areas, districts, and collection lines of milk plant. Each components of raw milk collected in province and district were significantly differed (p<0.001), but sampling stage were not effected on the composition of milk. In the monthly variation of milk composition, all of components excepted the content of ash in raw milk were lower in July and August, and tended to increas in October to January, and significantly (0.001) greater than in July and August. The correlation coefficients for the relation between fat content and total solids or protein were 0.635, 0.135 respectively, and between protein content and total solids or SNF were 0.652, 0.742.