Ex situ catalytic upgrading of lignocellulosic biomass components over vanadium contained H-MCM-41 catalysts

Kim, B.S.,Jeong, C.S.,Kim, J.M.,Park, S.B.,Park, S.H.,Jeon, J.K.,Jung, S.C.,Kim, S.C.,Park, Y.K. Elsevier Science Publishers 2016 CATALYSIS TODAY - Vol.265 No.-

<P>H-V-MCM-41 catalysts containing 5, 10, and 30 wt% of vanadium were synthesized and applied to the ex situ catalytic pyrolysis (CP) of three polymeric components of lignocellulosic biomass for the first time. Characterization of the catalysts was performed using N-2 adsorption-desorption, XRD, FT-IR, and NH3-TPD. The results of XRD analysis showed that 5 wt% and 10 wt% H-V-MCM-41 catalysts maintained the mesoporous structure, whereas the mesoporous structure was destroyed in 30 wt% H-V-MCM-41 with considerable amount of small V2O5 crystalline outside the framework. NH3-TPD showed that H-V-MCM-41 has mostly weak acid sites and that 10 wt% H-V-MCM-41 had the largest quantity of acid sites due to framework vanadium. In the case of CP of cellulose using Py-GC/MS, 10 wt% H-V-MCM-41 showed the highest catalytic activity for the production of valuable furanic compounds such as furfural because of the enhanced deoxygenation over the acid sites formed on framework vanadium. In the case of CP of xylan as well, 10 wt% H-V-MCM-41 led to the largest yield of mono-aromatics. The production of acetic acid was also promoted by H-V-MCM-41 catalysts. The CP of lignin over H-V-MCM-41 catalysts promoted substantially the production of important feedstock chemicals for the petrochemical industry: phenolics and mono-aromatics. (C) 2015 Elsevier B.V. All rights reserved.</P>

Effects of Y₂O₃ additions on the oxygen diffusion in top-seeded melt growth processed YBa₂Cu₃O_7-y superconductors

Jun, B.H.,Jung, S.A.,Park, S.D.,Park, B.J.,Han, Y.H.,Kim, C.J. North-Holland 2011 Physica. C, Superconductivity Vol.471 No.21

To understand the effect of Y<SUB>2</SUB>BaCuO<SUB>5</SUB> (Y211)/YBa<SUB>2</SUB>Cu<SUB>3</SUB>O<SUB>7-y</SUB> (Y123) interfaces on the oxygen diffusion in single grain YBa<SUB>2</SUB>Cu<SUB>3</SUB>O<SUB>7-y</SUB> superconductors, single grain Y123 superconductors with 0.05 and 0.3moles of Y<SUB>2</SUB>O<SUB>3</SUB> additions were fabricated by a top-seeded melt growth (TSMG) process. Y123 compacts with Y<SUB>2</SUB>O<SUB>3</SUB> additions were subjected to melt growth heating cycles with a cooling rate of 1<SUP>o</SUP>C/h through a peritectic temperature (1015<SUP>o</SUP>C) and then annealed at 450<SUP>o</SUP>C for 200h in flowing oxygen. The superconducting temperature (T<SUB>c</SUB>) and critical current density (J<SUB>c</SUB>) were estimated for the three different regions (top surface (s), intermediate (i) and center (c)) of samples. The amount of Y211/Y123 interface area in single grain Y123 superconductors was successfully controlled by Y<SUB>2</SUB>O<SUB>3</SUB> additions. The T<SUB>c</SUB> values of s regions were higher than those of i and c regions, which indicates the presence of more oxygen at the sample surfaces. In addition, the T<SUB>c</SUB> values of i and c regions of the Y123 sample with 0.3mole Y<SUB>2</SUB>O<SUB>3</SUB> addition were higher than those of the same regions of the Y123 sample with 0.05mole Y<SUB>2</SUB>O<SUB>3</SUB> addition due to the promoted oxygen diffusion through Y211/Y123 interfaces and other related defects. In spite of the promoted oxygen diffusion by Y<SUB>2</SUB>O<SUB>3</SUB> addition, the large T<SUB>c</SUB> difference among the regions still existed, which suggests sluggish oxygen diffusion into single Y123 grains.

초기성인의 생활습관과 당뇨에 대한 지식

소선이,마지은,고지윤,김은혜,박현화,서유진,서형은,유은미,이하늬,이혜인,정지연,현혜리,이자형,정덕유,강지숙 이화여자대학교 간호과학대학 2009 이화간호학회지 Vol.- No.43

Purposes :The purposes of this study was to investigate the self-managing status according to the life styles and the diabetic knowledge of early adulthood. The subjects in this study were 240people, the early adult aged twenties to thirties living in the metropolitan area. Data were collected by using self-administered questionnaires that measure about the knowledge of diabetes; the dietetic behavior; the knowledge of diet; the exercise behavior; the knowledge of exercise. Descriptive statistics, t-test, ANOVA, and correlation were used for data analysis. Result :1. At the knowledge of diabetes degree based on the general character, the subjects who had experiences of diabetic education have higher degree of the diabetic knowledge. 2. At the knowledge of diabetes degree according to the life style, the subjects who have regular diet are appeared highly. Also the subjects who don't take much food of animal origin have higher degree. 3. At the knowledge of diet based on the life style, the subjects who don't keep three times meals a day are appeared highly. Also the subjects who have regular diet have higher degree. 4. At the knowledge of exercise according to the life style, the subjects who take extra nutritions 3-4 times a week are appeared highly. Although the subjects tend to know about dietary, exercise and health management, it showed that they actually don't perform what they know in their everyday of life. The reason for this could be the lack of perceived seriousness about diabetes mellitus. Thus as nursing professionals, we should provide them proper health education and support. Moreover, advanced research on the empowerment is warranted.

Display of membrane proteins on the heterologous caveolae carved by caveolin-1 in the Escherichia coli cytoplasm

Shin, J.,Jung, Y.H.,Cho, D.H.,Park, M.,Lee, K.E.,Yang, Y.,Jeong, C.,Sung, B.H.,Sohn, J.H.,Park, J.B.,Kweon, D.H. IPC Science and Technology Press ; Elsevier Scienc 2015 Enzyme and microbial technology Vol.79 No.-

Caveolae are membrane-budding structures that exist in many vertebrate cells. One of the important functions of caveolae is to form membrane curvature and endocytic vesicles. Recently, it was shown that caveolae-like structures were formed in Escherichia coli through the expression of caveolin-1. This interesting structure seems to be versatile for a variety of biotechnological applications. Targeting of heterologous proteins in the caveolae-like structure should be the first question to be addressed for this purpose. Here we show that membrane proteins co-expressed with caveolin-1 are embedded into the heterologous caveolae (h-caveolae), the cavaolae-like structures formed inside the cell. Two transmembrane SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) proteins, Syntaxin 1a and vesicle-associated membrane protein 2 (VAMP2), were displayed on the h-caveolae surface. The size of the h-caveolae harboring the transmembrane proteins was ~100nm in diameter. The proteins were functional and faced outward on the h-caveolae. Multi-spanning transmembrane proteins FtsH and FeoB could be included in the h-caveolae, too. Furthermore, the recombinant E. coli cells were shown to endocytose substrate supplemented in the medium. These results provide a basis for exploiting the h-caveolae formed inside E. coli cells for future biotechnological applications.

Key Features in the Operation of KSTAR

Jong-Gu Kwak,Oh, Y. K.,Kim, K. P.,Kim, S. W.,Hong, S. H.,Chu, Y.,Lee, H. J.,Kim, Y. O.,Kim, J.,Park, S. L.,Hahn, S. H.,Park, M. K.,Kim, H. K.,Bak, J. G.,Bae, Y. S.,Ko, W. H.,Lee, S. G.,Lee, J. H.,Jung IEEE 2012 IEEE transactions on plasma science Vol.40 No.3

<P>The Korea Superconducting Tokamak Advanced Research (KSTAR) device is aimed at advanced tokamak (AT) research. Three years have passed since it achieved its first plasma in 2008. Because it is a superconducting machine and is working toward AT research, it has unique features in terms of the machine engineering and operation. The toroidal field (TF) magnet coils are made of Nb<SUB>3</SUB>Sn, which provide high TFs up to 3.5 T, and have been fully tested. The poloidal field (PF) magnet coils, consisting of both Nb<SUB>3</SUB>Sn and NbTi, which have a maximum current of 25 kA in their design, were tested up to 15 kA. A thermal hydraulic analysis is being conducted for PF magnet coil operation. All plasma-facing components (PFCs) are equipped with water cooled graphite tiles and have the capability of being baked up to 350°C. A startup scenario, which considered both the effect of the ferromagnetic material in the cable in conduit conductor jacket of the magnet coils as well as a nonferromagnetic up-down asymmetry in the cryostat structure, was developed and demonstrated its effectiveness by the last two year's reliable operations. Passive stabilizers and in-vessel control coils (IVCCs) are key components to realize AT operation in KSTAR. The segmented IVCC coils were connected to form circular coils for internal vertical control in 2010, and diverted plasmas with high elongation (κ~1.8, δ>;0.6) were achieved. A neutral beam injection (NBI) system was developed aiming at 2 MW, 300 s per ion source which meets the long-pulse requirement of KSTAR. An NBI ion source with a power of 1.7 MW at 100 kV has been commissioned for 10 s. Finally, ELMy H-modes were successfully produced with 1.3-MW NBI power at a plasma current of 0.6 MA in the 2010 campaign. The first H-mode discharge (#4200) in KSTAR was achieved one year earlier than officially planned and was done at B<SUB>T</SUB> = 2 T with I<SUB>p</SUB> = 0.6 MA in a well-balanced double null configuration after boronization on the PFC. Successful operations in the early days of KSTAR including H-mode experiments revealed the capability of advanced and steady-state operation which is essential for the international thermonuclear experimental reactor (ITER) and future fusion reactors.</P>

Effects of CO₂ addition on flame extinction in interacting H₂-air and CO-air premixed flames

Jung, S.W.,Park, J.,Kwon, O.B.,Kim, Y.J.,Keel, S.I.,Yun, J.H.,Lim, I.G. Butterworths [etc.] ; Elsevier Science Ltd 2014 Fuel Vol.136 No.-

The effects of CO<SUB>2</SUB> addition on the downstream interactions of H<SUB>2</SUB>-air and CO-air premixed flames were investigated. Flame stability diagrams mapping the extinction limits for various fuel concentrations as functions of the strain rate were developed for the downstream interactions between H<SUB>2</SUB>-air and CO-air premixed flames with 0-20% CO<SUB>2</SUB> addition. Of particular concern was the impact of the chemical reactions of the additional CO<SUB>2</SUB> on the flame extinction characteristics. The results showed that CO<SUB>2</SUB> addition suppressed the flammable regions appreciably and decreased the critical strain rate, opening up the lean extinction boundary. For highly stretched interacting flames, two flammable island regions on the maps were combined into one when 10% or 20% CO<SUB>2</SUB> was added to either the H<SUB>2</SUB>-air or CO-air premixed mixtures. The chemical reactions of the additional CO<SUB>2</SUB> were significant, especially for high strain rate flames, while the effect of the radiative heat loss of the additional CO<SUB>2</SUB> was minor, even for low strain rate flames. Such chemical reactions were determined by competition between the reaction steps for the consumption and production of HCO and the reverse reaction of CO+OH=CO<SUB>2</SUB>+H with the reaction step of H+O<SUB>2</SUB>→O+OH, an indicator of the overall reaction rate for the H atoms. This resulted in a weakened interacting flame. Such chemical reactions of the additional CO<SUB>2</SUB> were examined in detail to describe the flame characteristics.

Complete genome sequence of hyperthermophilic archaeon Thermococcus sp. ES1

Jung, J.H.,Kim, Y.T.,Jeon, E.J.,Seo, D.H.,Hensley, S.A.,Holden, J.F.,Lee, J.H.,Park, C.S. Elsevier Science Publishers 2014 Journal of biotechnology Vol.174 No.-

Thermococcus sp. strain ES1 is an anaerobic, hyperthermophilic archaeon from a hydrothermal vent that catabolizes sugars and peptides and produces H<SUB>2</SUB>S from S<SUP>o</SUP>, H<SUB>2</SUB>, acetate and CO<SUB>2</SUB> as its primary metabolites. We present the complete genome sequence of this strain (1,957,742bp) with a focus on its substrate utilization and metabolite production capabilities. The sequence will contribute to the development of heterotrophic archaea for bioenergy production and biogeochemical modeling in hydrothermal environments.

Pt deposited Pt-Pd/C electrocatalysts with the enhanced oxygen reduction activity

Park, J.H.,Sohn, Y.,Jung, D.H.,Kim, P.,Joo, J.B. Korean Society of Industrial and Engineering Chemi 2016 Journal of industrial and engineering chemistry Vol.36 No.-

<P>Reducing the cost of state-of-the-art Pt electrocatalysts while maintaining their oxygen reduction performance is always a hotspot in fuel cell research owing to their significant economic benefit for the commercialization of polymer electrolyte membrane fuel cells. Herein, we report a simple and cost-effective synthesis of Pt-Pd catalysts and a systematic study of their characteristics and catalytic performances for the oxygen reduction reaction (ORR). Pt-Pd bimetallic catalysts were prepared by a simple chemical deposition of Pt on the surface of Pd particles using a commercial Pd/C catalyst. During the synthesis, Pt precursor was reduced, and Pt layers were preferentially overgrown on the surface of the preexisting Pd particles resulting in Pd@Pt core-shell particles, which are favorable for ORR. By varying Pt precursors and the amount of Pt deposited, the physicochemical and electrochemical properties of the Pt-Pd catalysts were optimized. The formation of a thin Pt layer on Pd surface is more favorable, when using Pt(NH3)(4)Cl-2 center dot xH(2)O rather than H2PtCl6 center dot xH(2)O. As the amount of Pt increased from 0 to 10%, the surface properties of metal particles changed to similar to that of Pt, and the resulting catalysts mainly consist of a Pt-rich layer with a Pd core such as the Pd@Pt core-shell configuration. Pt(10%)Pd/C catalyst prepared by using Pt(NH3)(4)Cl-2 center dot xH(2)O exhibited a significant improvement in the ORR with the mass activities of 221 and 53 mA/mgpGm at 0.85 and 0.9 V, respectively, which are beatable values compared to those (219 and 59 mA/mg(Pt) at 0.85 and 0.9 V) of commercial Pt/C catalysts. The performance improvement of our bimetallic Pt-Pd/C catalysts mainly originate from the formation of an active Pt surface on the Pd core. In addition, considering that Pd is generally less expensive than Pt, these catalysts should have much better ORR performance and more feasibility of decreasing the total cost of fuel cells. In this study, the characteristics, electrochemical behaviors, and ORR performance improvements of the simply prepared Pt(x)-Pd/C core-shell catalysts were systemically investigated and are discussed. (C) 2016 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.</P>

스마트폰을 이용하는 노인의 우울, 고독감과 사회적 지지에 대한 연구

이세미,장혜원,정여주,김여울,정지혜,김지원,김주영,양혜린,박지혜,정유리 이화여자대학교 간호과학대학 2015 이화간호학회지 Vol.- No.49

Purpose: The purpose of this study was to investigate depression, loneliness, and social support status of the elderly using smartphone. Method: In this descriptive design study, 100 elderly people using smartphone were recruited through convenient sampling between August and September, 2014. Questionnaires used for this study were CES-D(The Center for Epidemiological Studies-Depression Scale), UCLA Loneliness Scale, and social support scale developed by Park. Data were statistically analyzed using SPSS 22.0 program with descriptive statistics, independent t-test, one way ANOVA with Scheffe's test, and χ2-test. Result: Smartphone usage duration had significant influence on depression(=0.000) and loneliness(=0.001) of the elderly using smartphone. In detail, depression scores of participants using smartphone less than 6 months were higher than participants of more than 2 years(p=0.004). And both depression and loneliness scores of participants using smartphone 6 to 1 year were higher than participants of more than 2 years(=0.001). But smartphone usage time had no significant influence on depression and loneliness of the elderly using smartphone. Conclusion: The result of this study suggest that smartphone usage duration is significantly related to both depression and loneliness of the elderly. Therefore, smartphone education program for the elderly would be a helpful intervention for depression and loneliness of the elderly. And further studies are required with more sample size and more systematic data collecting methods to confirm these results.

인슐린비의존형 당뇨병 환자에서 말초신경병증과 저인슐린혈증

정연실,이기영,이성광,김홍규,박혜영,강문호 대한당뇨병학회 2000 Diabetes and Metabolism Journal Vol.24 No.2

Background: There is little information on the risk factors for diabetic polyneuropathy other than glycemic control and duration of diabetes. The relation between diabetic polyneuropathy and hypoinsulinemia is controversial. This study is to determine whether hypoinsulinemia is an additional factor influencing the development of polyneuropathy in patients with type 2 diabetes. Methods: We performed an oral glucose tolerance test with C-peptide measurement in 192 patients with type 2 diabetes. Peripheral polyneuropathy was diagnosed when the patients had both typical symptoms of polyneuropathy and abnormal physical findings or NCV. We analysed the relation between metabolic variables including fasting and postprandial C-peptide levels and diabetic polyneuropathy. Results: In addition to retinopathy and nephropathy, duration of diabetes, low C-peptide level (fasting and postprandial), insulin use, and high HDL-cholesterol level were associated with diabetic polyneuropathy. Multivariate logistic regression model revealed that an independent association of diabetes duration and postprandial 2-hour C-peptide concentration with polyneuropathy. When we stratified the patients into the two groups according to the median duration of diabetes (8 years), the association of low postprandial C-peptide concentration with polyneuropathy was significant only in the shorter duration group ($lt; 8 years). However, significant association of HbA_(ic) level was shown in the longer duration group. Conclusion: Decreased insulin secretory function of the pancreas as well as increased duration of diabetes was independently associated with diabetic polyneuropathy in patients with type 2 diabetes. Hypoinsulinemia might be an additional risk factor for the development of diabetic polyneuropathy in type 2 diabetic patients, particularly with short duration. To confirm these relationship further longitudinal study in a large cohort is necessary.