• Title/Summary/Keyword: HDS

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Hydrodesulfuriztion of Thiophene over Neodymium Added Nickel Catalysts (네오디뮴이 첨가된 니켈 촉매의 티오펜 탈황 반응)

  • Moon, Young-Hwan;Ihm, Son-Ki
    • Applied Chemistry for Engineering
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    • v.7 no.5
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    • pp.913-924
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    • 1996
  • In this study HDS(hydrodesulfurization) of thiophene was researched over nickel catalysts added with small amounts of neodymium which were prepared by different methods such as unsupported coprepricipitated NdNi catalysts, unsupported intermetallic $NdNi_5$ catalysts, and carbon supported NdNi catalyst. The HDS activity was remarkably increased when a small amounts of neodymium was added to unsupported coprecipitated Ni catalysts. Thus it was known that the role of Nd is important in HDS of thiophene of Ni catalysts. For the case of unsupported intermetallic $NdNi_5$, the intermetallic crystallinity was destroyed to oxide and sulfide after calcination and presulfidation respectively. The HDS activity of thiophene can be explained by surface area of unsupported catalysts. And Nd acts like as structural promoter keeping the high surface area of unsupported catalysts. The HDS activity was increased by each ten times based on 1 gr. of nickel in the order of unsupported intermetallic $NdNi_5$, unsupported coprecipitated NdNi, and carbon supported NdNi catalysts according to different preparation method of catalysts.

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The past, present, and future of humidifier disinfectant-associated interstitial lung diseases in children

  • Lee, Eun;Lee, So-Yeon;Hong, Soo-Jong
    • Clinical and Experimental Pediatrics
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    • v.63 no.7
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    • pp.251-258
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    • 2020
  • Exposure to environmental factors can cause interstitial lung diseases (ILDs); however, such types of ILDs are rare. From 2007 to 2011, an ILD epidemic occurred in South Korea owing to inhalational exposure to toxic chemicals in humidifier disinfectants (HDs). HD-associated ILDs (HD-ILDs) are characterized by rapidly progressing respiratory failure with pulmonary fibrosis and a high mortality rate of 43.8%-58.0%. Although 18.1%-31.1% of the general population used HDs, only a small proportion of HD users were diagnosed with HD-ILDs. This finding suggests that investigation of the pathophysiologies underlying HD-ILDs is needed in addition to the identification of susceptibility to HD-ILDs. Further, there have been several concerns regarding the diverse health effects of exposure to toxic chemicals in HDs, including those that have not been identified, and long-term prognoses in terms of pulmonary function and residual pulmonary lesions observed on follow-up chest images. In this review, we summarize the clinical features, pathologic findings, and changes in radiologic findings over time in patients with HD-ILDs and the results of previous experimental research on the mechanisms underlying the effects of toxic chemicals in HDs. Studies are currently underway to identify the pathophysiologies of HD-ILDs and possible health effects of exposure to HDs along with the development of targeted therapeutic strategies. The experience of identification of HD-ILDs has encouraged stricter control of safe chemicals in everyday life.

Performance Improvement Using Iterative Two-Dimensional Soft Output Viterbi Algorithm Associated with Noise Filter for Holographic Data Storage Systems

  • Nguyen, Dinh-Chi;Lee, Jaejin
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.39A no.3
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    • pp.121-126
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    • 2014
  • Demand of the data storage becomes more and more growing. This requests the next generation of storage devices to have the dominated storage capability associated with superfast read/write rate. Holographic data storage (HDS) is investigated for a long time and is considered to be a candidate for the future storage system. However, it has two-dimensional intersymbol interference that conventional one-dimensional detection solutions have not yet handled strictly because of the complexity level of system as well as the cost. We propose a new scheme that combines iterative soft output Viterbi algorithm with noise filter for improving the bit error rate performance of HDS.

The Simultaneous Hydrocracking and Hydrodesulfurization over CoPtMo/LaY Catalyst (CoPtMo/LaY 촉매상에서 동시적인 수소화분해반응 및 수소첨가탈황반응)

  • 김문찬;김경림
    • Journal of Korean Society for Atmospheric Environment
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    • v.11 no.2
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    • pp.171-178
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    • 1995
  • The hydrodesulfurization (HDS) of dibenzothiophene (DBT) were performed simultaneously over CoPtMo/LaY catalyst under high H$_{2}$ pressure. The structure and physical properties of this catalyst were characterized using XRD, IR and surface area analyzer. The origin of acid site was mainly Bronsted. The structures of impregnated molybdenum and platinum were deactivated by DBT to MoS$_{2}$ and PtS, respectively. The activities of the HDS and the hydrocracking increased with increasing temperature and pressure. They decreased with increasing the DBT mole ratio(DBT/n-heptane). They remained constant with increasing the H$_{2}$/H.C. mole ratio. With increasing pressure and DBT mole ratio, the products of secondary cracking increased. To perform simultaneous HDS and hydrocracking effectively, the optimum condition were 500.deg.C, 4MPa.

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The Effects of Treadmill Training on Neurotrophins and Immediately Early Protein in Obese Rats (트레드밀 트레이닝이 비만 쥐의 neurotrophins와 초기발현 단백질에 미치는 영향)

  • Woo, Jin-Hee;Shin, Ki-Ok;Yeo, Nam-Heoh;Park, So-Young;Kang, Sung-Hwun
    • Journal of Life Science
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    • v.21 no.7
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    • pp.985-991
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    • 2011
  • The purpose of this study was to investigate the biological effect of obesity-induced oxidative damage on neurogenesis and early protein expression. Obesity was induced I thirty 4-week old male Sprague-Dawley rats through a high fat diet for 15 weeks. After one week of environmental adaptation, the rats were divided into 2 groups: high fat diet sedentary group (HDS, n=15) and high fat diet training group (HDT, n=15). Exercise training was performed 5 times a week for 8 weeks, with mild-intensity treadmill running for weeks 1-4 and moderate-intensity treadmill running for weeks 5-8. After the 8 week training period, we analyzed lipid profiles, serum 8-hydroxyguanosine (8-OHdG), liver tissue malondialdehyde (MDA) related to oxidative damage factors, nerve growth factor (NGF), brain derived neurotrophic factor (BDNF), c-fos, c-jun, and extracellular signal regulated kinase (Erk) in the hippocampus. The results of this study are as follows. There were differences between HDS and HDT in triglyceride (TG) and total cholesterol (TC) (p<0.05). In high density lipoprotein (HDL-c), the HDT was higher than HDS after treadmill training (p<0.05). In 8-OHdG, the HDT was lower than HDS after treadmill training (p<0.05). Genetic expressions of c-jun, BDNF and MDA in the HDT were higher than in the HDS after treadmill training in hippocampus (p<0.05). Therefore, we conclude that 8 weeks of treadmill training can improve imbalanced lipid profiles, reduce oxidative damage, and activate neurogenesis in obese rats.

Preparation and Catalytic Activity of Morphologically Controlled MoO3/SiO2 for Hydrodesulfurization (결정상과 분산도의 조절이 가능한 MoO3/SiO2 촉매의 제조 및 탈황반응특성 연구)

  • Ha, Jin-Wook
    • Applied Chemistry for Engineering
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    • v.10 no.2
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    • pp.231-236
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    • 1999
  • Several series of morphologically controlled $MoO_3$/$SiO_2$ catalysts were prepared, characterized, and tested for hydrodesulfurization (HDS) of dibenzothiophene (DBT) activity. Molybdenum surface loaded with 4.0 atoms $Mo/nm^2$ was prepared as sintered hexagonal and sintered orthorhombic, as well as a novel "well dispersed hexagonal" phase. Characterization by XRD, Raman, and $O_2$ chemisorption results reveals that the dispersion of $MoO_3$ over silica depends on the final $MoO_3$ phase in the order of; sintered hexagonal < sintered orthorhombic < dispersed hexagonal phase. Temperature programmed reduction (TPR) results show that both bulk and dispersed microcrystalline of $MoO_3$ reduce to $MoO_2$ at $650^{\circ}C$ and to Mo metal at $1000^{\circ}C$. HDS of DBT was performed in a differential reactor at 30 atm over the temperature range $350{\sim}500^{\circ}C$. Activity of $MoO_3$/$SiO_2$ toward HDS of DBT is proportional to dispersion.

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HDS Method for Fast Searching of Motion Vector (움직임 벡터의 빠른 추정을 위한 HDS기법)

  • 김미영
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.8 no.2
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    • pp.338-343
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    • 2004
  • In Block Matching Algorithm (BMA), a search pattern has a very important affect on the search time and the output quality. In this paper, we propose the HDS( Half Diamond Search) pattern based on the cross center-biased distribution property of a motion vector. At lust, the 4 points in the above, below, left, and right around the search center is calculated to decide the point of the MBD (Minimum Block Distortion). And an above point of the MBD is checked to calculate the SAD. If the SAD is less than the previous MBD, this process is repeated. Otherwise, the left and right points of MBD are calculated to decide the points that have the MBD between two points. These processes are repeated to the predicted direction for motion estimation. Experiments show that the speedup improvement of the proposed algorithm can be up to 23% while maintaining similar image quality.

The Characteristics of Depression in Cancer Patients on Chemotherapy (항암제 투여 환자의 우울 양상)

  • Joo, Yeol;Seo, Wan-Seok;Kim, Jin-Sung;Lee, Jong-Bum;Cheung, Seung-Douk;Song, Shin-Ho;Bai, Dai-Seog;Lee, Kyung-Hee;Hyun, Myung-Soo
    • Korean Journal of Psychosomatic Medicine
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    • v.10 no.2
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    • pp.154-165
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    • 2002
  • Objectives : The purpose of this study was to identify characteristics of depression in cancer patients treated with chemotherapy. Methods : Subjects were 37 cancer inpatients of oncology in Yeungnam university hospital. BDI and ZDS were done and HDS was performed through semistructured interview. Results: 1) There were no significant differences of depression scale score according to sex, education, religion, marital status. 2) The mean scores of BDI, ZDS and HDS in 37 cancer patients were 18.27${\pm}$7.73, 36.51${\pm}$10.82, 15.14${\pm}$6.60, respectively. 3) HDS, ZDS scores were significantly higher in other cancer group receiving high dose chemotherapy. 4) Item score for depressed mood, diurnal variation(p<0.001), dissatisfaction(p<0.01), physical anxiety, decreased libido, sleep disturbance(p<0.05) were significantly higher in other cancer group than others. 5) Eight patients were diagnosed as having major depressive disorder, 11 as adjustment disorder, and 18 patients had no axis I diagnosis. 6) In major depressive disorder group, the score of the depressed mood item in ZDS was high (p<0.05). HDS item score for depressed mood, work difficulty, anxiey(p<0.001), psychomotor retardation(p<0.01) were significantly higher in major depressive disorder group. 7) In patients with adjustment disorder, ZDS item score of constipation(p<0.001), fatigue, anorexia (p<0.01), emptiness, sleep disturbance, dissatisfaction, weight loss(p<0.01) were high. HDS item score of hypochondriasis(p<0.01), agitation(p<0.01), fatigue, decreased libido(p<0.05) were significantly higher in adjustment disorder group. Conclusion : Some psychiatric disorders, such as adjustment disorder and major depressive disorder were common in the cancer patients in chemotherapy. Psychiatric intervention will increase compliance of cancer treatment and improve the quality of life. This study suggests that it would be important to consider the nature of somatic symptoms in diagnosing depression in cancer patients.

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Estimation of the Elastic Stiffness of TW-HDS Assembly (너비감소 판형 홀다운스프링 집합체의 탄성강성도 평가)

  • Song, Kee-Nam
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.21 no.1
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    • pp.180-187
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    • 1997
  • A formula for estimating the elastic stiffness of TW-HDS with a uniformly tapered width from w$_{0}$ to w$_{1}$ over the length, has been analytically derived based on Euler beam theory and Castigliano's theorem. Elastic stiffnesses of the TW-HDSs designed in the same dimensional design spaces as the KOFA HDSs have been estimated from the derived formula, in addition, a sensitivity study on the elastic stiffness of the TW-HDSs has been carried out. Analysis results show that elastic stiffnesses of the TW-HDSs have been by far higher than those of the KOFA HDSs, and that, as the effects of axial and shear force on the elastic stiffness have been 0.15-0.21%, most of the elastic stiffness is attributed to the bending moment. As a result of sensitivity analysis, the elastic stiffness sensitivity at each design variable is quantified and design variables having remarkable sensitivity are identified. Among the design variables, leaf thickness is identified as that of having the most remarkable sensitivity of the elastic stiffness.