• Title/Summary/Keyword: DBT

Search Result 113, Processing Time 0.031 seconds

Characteristics of Oxidative Desulfurization(ODS) of Sulfur Compounds in Diesel Fuel over Ti-grafted SBA-15 Catalyst (Ti-grafted SBA-15 촉매를 이용한 경유유분 중의 황화합물의 선택산화탈황 특성)

  • Cho, Chin-Soo;Jeong, Kwang-Eun;Chae, Ho-Jeong;Kim, Chul-Ung;Jeong, Soon-Yong;Oh, Sung-Geun
    • Korean Chemical Engineering Research
    • /
    • v.46 no.5
    • /
    • pp.845-851
    • /
    • 2008
  • Oxidative desulfurizaton of model sulfur compounds and Industrial diesel fuel(LCO; Light Cycle Oil) over Ti-grafted SBA-15 catalyst was studied in a batch reactor with tert-Butyl Hydroperoxide(TBHP) as oxidant. Effects of Ti loading, TBHP/Sulfur mole ratio, reaction temperature on ODS activity and kinetic parameters were investigated. Ti-grafted SBA-15 catalyst showed higher sulfur removal activity in the oxidative desulfurization reaction of refractory sulfur compounds(DBT and 4, 6-DMDBT) and LCO, suggesting that Ti-grafted SBA-15 catalyst could be a good candidate for ODS catalyst.

Application of a Gas Chromatography/Mass Spectrometric Method for the Determination of Butyltin Compounds in Sediment

  • Won, Yong-Il;Jung, Pyong-Gil;Chung, Min-Young;Kim, Byung-Joo;Yim, Yong-Heon;So, Hun-Young;Kim, Yong-Seong
    • Bulletin of the Korean Chemical Society
    • /
    • v.25 no.10
    • /
    • pp.1508-1512
    • /
    • 2004
  • A gas chromatography/mass spectrometric (GC/MS) method has been developed for the determination of trace mono-n-butyltin (MBT), di-n-butyltin (DBT), and tri-n-butyltin (TBT) compounds in sediments. Samples were extracted by 10% acetic acid in methanol containing 0.03% tropolone and were then derivatized for GC/MS analysis. Ethylation by sodium tetraethylborate and phenylation by sodium tetraphenylborate were evaluated as a derivatization reaction of the organotins in sample extract. n-Hexane was added into reaction media in the beginning of the reaction for the continuous extraction of derivatized organotins. Ethylation requires less than 2 hours to get proper derivatization yields for MBT, DBT, and TBT altogether and produces relatively low amounts of side reaction products. Compared to ethylation, phenylation requires much longer time but provides relatively lower yield and produces considerable amounts of side reaction products. Therefore, the ethylation reaction was applied for the analysis of organotin compounds in sediment. An isotope dilution mass spectrometric (IDMS) method based on GC/MS has been applied to the accurate determination of DBT compounds in the sediments. The IDMS results from the analyses of sediment samples showed a reasonable repeatability and a good agreement with the values obtained by IDMS based on liquid chromatography/induced coupled plasma/mass spectrometry.

Pathogenicity Determinants of Sclerotinia sclerotiorum and Their Association to Its Aggressiveness on Brassica juncea

  • Gill, Rupeet;Sandhu, Prabhjodh S.;Sharma, Sanjula;Sharma, Pankaj
    • The Plant Pathology Journal
    • /
    • v.37 no.4
    • /
    • pp.365-374
    • /
    • 2021
  • White rot or stem rot caused by Sclerotinia sclerotiorum is one of the most destructive fungal diseases that have become a serious threat to the successful cultivation of oilseed Brassicas. The study was designed with an aim to investigate the association between the pathogenic aggressiveness and pathogenicity determinants of this pathogen specifically in Brassica for the first time. For this, a total of 58 isolates of S. sclerotiorum from different geographical regions were collected and purified. These isolates were inoculated on a Brassica juncea cv. RL-1359 and they exhibited high level of variation in their disease progression. The isolates were grouped and then 24 isolates were selected for the biochemical analysis of pathogenicity determinants. The isolates varied significantly with respect to their total organic acids, oxalic acid production and pectin methyl esterase and polygalacturonase activity. The oxalic acid production corresponded to the disease progression of the isolates; the isolates with higher oxalic acid production were the more aggressive ones and vice-versa. This is, in our knowledge, the first study to establish a correlation between oxalic acid production and pathogenic aggressiveness of S. sclerotiorum on B. juncea. However, the pectinases' enzyme activity did not follow the trend as of disease progression. These suggest an indispensable role of oxalic acid in pathogenicity of the fungus and the potential to be used as biochemical marker for preliminary assessment of pathogenic aggressiveness of various isolates before incorporating them in a breeding program.

An Experimental Study for the Effect of Operating Condition of the Air Handling Unit on the Performance of Humidifying Elements (공조기 운전 조건이 가습 소자의 성능에 미치는 영향에 대한 실험 연구)

  • Kim, Nae-Hyun
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.19 no.11
    • /
    • pp.326-331
    • /
    • 2018
  • Evaporative humidification using a humidifying element is used widely for the humidification of a building or a data center. The performance of a humidifying element is commonly expressed as the humidification efficiency, which is assumed to be independent of the air temperature or humidity. To verify this assumption, a series of tests were conducted under two air conditions - data center ($25^{\circ}C$ DBT, $15^{\circ}C$ WBT) and commercial building ($35^{\circ}C$ DBT, $21^{\circ}C$ WBT) - using humidifying elements made from cellulose/PET and changing the frontal air velocity from 1.0 m/s to 4.5 m/s. Three samples having a 100 mm, 200 mm, or 300 mm depth were tested. The results showed that the humidification efficiency is dependent on the air condition. Indeed, even dehumidification occurred at the inlet of the humidifying element at the air condition of commercial building. This suggests that a proper thermal model should account for the inlet area, where the amount of moisture transfer may be different from the other part of the humidification element. As the depth of the element increased from 100 mm to 200 mm, the humidification efficiency increased by 29%. With further increases to 300 mm, it increased by 42%. On the other hand, the pressure drop also increased by 47% and 86%.

Enhancing Empathic Reasoning of Large Language Models Based on Psychotherapy Models for AI-assisted Social Support (인공지능 기반 사회적 지지를 위한 대형언어모형의 공감적 추론 향상: 심리치료 모형을 중심으로)

  • Yoon Kyung Lee;Inju Lee;Minjung Shin;Seoyeon Bae;Sowon Hahn
    • Korean Journal of Cognitive Science
    • /
    • v.35 no.1
    • /
    • pp.23-48
    • /
    • 2024
  • Building human-aligned artificial intelligence (AI) for social support remains challenging despite the advancement of Large Language Models. We present a novel method, the Chain of Empathy (CoE) prompting, that utilizes insights from psychotherapy to induce LLMs to reason about human emotional states. This method is inspired by various psychotherapy approaches-Cognitive-Behavioral Therapy (CBT), Dialectical Behavior Therapy (DBT), Person-Centered Therapy (PCT), and Reality Therapy (RT)-each leading to different patterns of interpreting clients' mental states. LLMs without CoE reasoning generated predominantly exploratory responses. However, when LLMs used CoE reasoning, we found a more comprehensive range of empathic responses aligned with each psychotherapy model's different reasoning patterns. For empathic expression classification, the CBT-based CoE resulted in the most balanced classification of empathic expression labels and the text generation of empathic responses. However, regarding emotion reasoning, other approaches like DBT and PCT showed higher performance in emotion reaction classification. We further conducted qualitative analysis and alignment scoring of each prompt-generated output. The findings underscore the importance of understanding the emotional context and how it affects human-AI communication. Our research contributes to understanding how psychotherapy models can be incorporated into LLMs, facilitating the development of context-aware, safe, and empathically responsive AI.

Facing Stress Through Mindfulness and Its Clinical Use (마인드풀니스를 통한 스트레스 대처와 임상적 활용)

  • Kim, Kyung-Seung
    • Korean Journal of Psychosomatic Medicine
    • /
    • v.16 no.1
    • /
    • pp.5-16
    • /
    • 2008
  • Several treatment programs putting mindfulness to practical use are being utilized in the various clinical settings as well as educational fields since 1980's. In this article, I studied several books and journals related with mindfulness and tried to show that mindfulness may have its neural circuits in the brain and can be utilized in the form of MBSR, MBCT, ACT, DBT not only to reduce stress and the symptoms of various psychosomatic conditions but to be applied to psychiatric illness such as, anxiety disorders, depressive disorders, and eating disorders, predicting its usefulness as a new psycho-social treatment.

  • PDF

Contamination and Bioaccumulation of Butyltin Compounds Inside Jeju Harbor of Jeju Island, Korea

  • Kam, Sang-Kyu;Cho, Eun-Il;Lee, Min-Gyu
    • Journal of Environmental Science International
    • /
    • v.20 no.2
    • /
    • pp.163-174
    • /
    • 2011
  • Butyltin compounds in seawater, sediments and organisms inside Jeju Harbor of Jeju Island, Korea, were quantitatively determined to assess the extent of contamination and to evaluate the bioaccumulation in Thais clavigera (gastropod), Liolophura japonica and Cellana nigrolineata. In addition, imposex in T. clavigera was used to assess the sublethal effect of tributyltin compounds and its usage as a specific biomarker for these compounds was also studied. The main species in seawater was tributyltin (TBT) in March and June, monobutyltin (MBT) in August, but in sediments and organisms it was dibutyltin (DBT) and TBT, respectively, irrespective of survey time. TBT, the most toxic to aquatic organisms among BTs, was found at concentrations which were sufficient to have a serous effect on the sensitive organisms upon chronic exposure. The high correlations (r>0.7) between BTs indicated that DBT and MBT were mainly degraded from TBT based on antifouling paints and their sources were negligible. The sedimentary organic matters have little influence on the distribution of BTs in marine environment and the lipid content in T. clavigera showed a significant correlation with TBT concentrations. Measurement of imposex T. clavigera was expected to be a very helpful tool for preliminary survey of BTs prior to trace analysis of those.