• Title/Summary/Keyword: nit

Search Result 232, Processing Time 0.032 seconds

Study on Recovery of Separated Hydrofluoric Acid, Nitric Acid and Acetic Acid Respectively from Mixed Waste Acid Produced during Semiconductor Wafer Process (반도체 웨이퍼 제조공정(製造工程) 중 발생혼합폐산(發生混合廢酸)으로부터 불산, 질산 및 초산의 각 산 회수(回收)에 관한 연구(硏究))

  • Kim, Ju-Yup;Kim, Hyun-Sang;Bae, Woo-Keun
    • Resources Recycling
    • /
    • v.18 no.4
    • /
    • pp.62-69
    • /
    • 2009
  • We researched separation of mixed waste acids with HF, $CH_3COOH$, $HNO_3$ that were produced during a semiconductor wafer process to recycle these acids. At first, we manufactured the fluoride compound in form of $Na_2SiF_6$ by precipitating HF using $NaNO_3$ and Si powder. The concentration of HF was reduced from the initial concentration of 127 g/L to 0.5 g/L with an HF recovery ratio of 99.5%. After the manufacture of $Na_2SiF_6$, the concentration of $HNO_3$ and $CH_3COOH$ demonstrated 502 g/L and 117 g/L respectively. Following these findings we added NaOH in this $CH_3COOH/HNO_3$ mixed acid in order to obtain pH=4. Next we separated the $CH_3COOH$ and recoverd it through the use of vaccum evaporation at -440 mmHg, $95^{\circ}C$. The concentration of the recovered $CH_3COOH$ was approximately 15% and the recovery ratio of $CH_3COOH$ was over 85%. We precipitated the $NaNO_3$ by cooling the concentrated solution to $20^{\circ}C$ with a $HNO_3$ recovery ratio of over 93%. We confirmed that only $Na_2SiF_6$ and $NaNO_3$ were manufactured by XRD analysis after drying these precipitants at $90^{\circ}C$. The precipitants demonstrated a purity of approximately 97% and 98% respectively. Therefore, the purity of the precipitants proved to be similar to that of commercial products.

Isolation and Characterization of Cryptococcus sp. CS-2 Secreting Polygalacturonase from Soil (토양으로부터 Cryptococcus sp. CS-2의 분리 및 균주가 분비하는 Polygalacturonase의 특성에 관한 연구)

  • 강희경;문명님;임채영;양영기
    • Korean Journal of Microbiology
    • /
    • v.35 no.2
    • /
    • pp.158-163
    • /
    • 1999
  • A ploygalacturonase-produchg yeast was isolated from Cheju soil by selective eivichment media. One strain which has the highesl activity of polygalacturonase was selected. The characle~ishcs of the strain CS-2 were as follows: CS-2 utilized xylose. sucrose, maltose, u.ehalose, cellobiose. melibiose, lactose, raffinose, inosiiol, dulicilol, and dextrose, but did not utilized galactose, nitrate. nit~te, and lysine. Growth of CS-2 was inhibited by cyclohexamide, 1% acetic acid, and high concenaation (over 50%) of glucose. It grew at $30^{\circ}C$ but did 'IIOL $35^{\circ}C$. The cell size ofthe strain CS-2 was 2.9 p ~ n in length and 1.3 $\mu$ in diameter. Vegetable reproductmn was multiple budding and ascospre was present I to 4. Pseudomycelia or true myceliua formation were not observed In any of the cullureq. These results suggest that strain CS-2 is most likely a strain related Cryptococcus spp. (Cryptococcu spp. CS-2). When polygalacturonase or ihe yeast was induced by addition of polygalactoronic acid, polygalacturonase activity was detected in culture supernatent. There was a peak of specific activity a1 he mid-stationary phase(3 days culture) of growth. Polygalacturonase specific activity of Crylmcoccus sp. CS-2 was 2.96 unitsling. The molecular weighl ol'polygalacturonase was showed to be 46 KDa by both SDS-PAGE and activity stailling.

  • PDF

Crystal Structures of Vacuum Dehydrated Fully $Cd^{2+}$-Exchanged Zeolite A and of Its iodine Sorption Complex (카드뮴 이온으로 완전히 치환한 제올라이트 A를 진공 탈수한 구조와 이것에 요오드를 흡착한 결정구조)

  • Jang, Se-Bok;Han, Young-Wook;Kim, Yang
    • Korean Journal of Crystallography
    • /
    • v.4 no.2
    • /
    • pp.54-62
    • /
    • 1993
  • The crystal shnture of dehydrated fully Cd2+-exchanged zeolite A evacuated at 2 × 10-6 Torr and 650℃ (a:12.189(2) A) and of its iodine sorption corrplex (a:12.168(2)A) have been netsmlmn by single uystal x-ray diffraction techliques in the cubic space group hkTn at 21(1)℃. The strutures were refined to final error indices, Ri:0.057 and R2 =0.063 with 186 reflections and Rl:0.082 and R2:0.085 with 181 reflections, respectively, for which 1>3σ(In both structure, six lie at two distinguished threefold axes of unit cell ten the crystal structure of an iodine sorption complex of Cd6-A four Cd2+ ions are recessed 0.69(1) A into the large cavity to complex each with from the (111) plane of 0(3), whereas two Cd2+ ions recessed 0.68(1) A into the sodalite unit Awximately 4.0 l3ions per nit cell are sorbed. Each bridge between a Cd2+ ion and 8-ring oxygens ((I-I-I)= 117(1) ˚ and 0(1)-I(1)-I(2)=172(1)). The near linear I-I-0 angle and its interatomic distance (I-0=3.57(3) A) are indicative of a weak charge transfer interacticn between the frarrework oxygen and iodine. The existence of In3 inside the large cavity indicates that the If ions and H ions may be produced by reaction of In vapor with water molecules which maybe associated with Cd2+ ions in partially dehydrated Cd6-A In3- ions may be produced by the combination of I- and I2.

  • PDF

Effects of Ginseng Saponins on the Induction of Differentiation in Mammary Epithelial Cells and Mammary tumor Cells (홍삼 사포닌에 의한 유선상피 및 유선암세포의 분화 유도 효과 연구)

  • 오미숙;백기주;전성실;김규원;최강주;김남득
    • Journal of Ginseng Research
    • /
    • v.24 no.4
    • /
    • pp.188-195
    • /
    • 2000
  • Using Ginseng saponins (crude saponin and total saponin) and ginsenoside Rbl Rb2, Rc, Rd, Re, Rhl, and Rh2 in this study, we have examined the effects of the compounds on the induction of differentiation in normal rat mammary epithelial cells and 7,12-dimethylbenz[a]anthracene (DMBA)-induced mammary tumor cells in culture. When normal rat mammary organoids were cultured in 100-mm culture plates in the presence or absence of ginseng saponins, there were four different cell colonies after two weeks in culture: cobble stone, spindle, honey comb, and senescence type colonies. Ginseng saponins showed different effects on the development of each colonies. Scrape-loading dye transfer tech-nique was performed to measure the effects of total saponin, Rhl, and Rh2 on intercellular junctional communication. Intercellular communication was not observed at short cultilral time, e.g., four or seven days, but when it cultured it up to two weeks, cell to cell communication was observed in saponin-treated cells. Reconstituted basement membrane, Matrigel, supported the growth and development several different multicellular structures from normal mammary organoids (e.g., ductal, webbed, stellate, and squamous colonies) or DMBA-induced mammary tumor (e.g., alveolar unit, foamy alveolar unit, squamous metaplasia, lobule-ductal, stellate, and webbed colony). In ginseng saponin-treated groups, webbed colonies were more and squamous colonies were less than control group. Moreover, the ductal colonies, marker tructure of well-differentiate mammary epithelial cells, were developed more in saponin-treated group than in control group. In conclusion, ginseng saponins affected on the differentiation of normal rat mammary epithelial cells and DMBA-induced mammary tumor cells in culture.

  • PDF

Pre-and Post-ishemic Changes of the Constituent Enzymes in Isolated Rabbit's Myocardium (허혈전후 적출 가토 심근내의 구성 효소의 변화)

  • 천수봉;전도환;이재성;김송명
    • Journal of Chest Surgery
    • /
    • v.33 no.2
    • /
    • pp.117-124
    • /
    • 2000
  • Background: Nucleoside transport inhibitor(NTI) Keeps AMP, ADP, ATP levels high in myocytes by inhibiting adenosine cataboilsm so that it may preserve the myocardial contractability during ischemia In this study we investigated the effects of cyclic AMP phosphodiesterase inhibor(C-AMP PDSI) and S-P-nitrobenzyl-6 -thioniosine(NBT; a sort of NIT) on myocadial preservation and changes of constituent enzyme. Material and method: Twenty-six isolated rabbit hearts were perfused with Krebs-Henseleit buffer solution for 20 minutes arrested for 20 minutes and ten reperfused for 30 minutes. The following four groups were prepared and hemodynamic changes coronary effluent lactate dehydrogenase (LDH) a-hydroxybutylic accid(a-HBD) levels and myocardial LDH creatine kinase-MB (CK-MB) adenosine deaminase(ADA) a-HBD levels and myocardial LDH creatine kinase-MB (CK-MB) adenosine deaminase(ADA) a-HBD levels were analysed before and after cardiac arest ; Group I(control) ; the heart was only perfused with K-H ; Group II ; the heart was perfused with K-H including C-AMP PDSI(Amrinone 25mg/L); Group III ; the heart was perfused with K-H including NBT(4.19mg/L) ; Group IV ; the heart was perfused with K-H including C-AMP PDSI + NBT. Result : Left venticular developed pressure(LVDP) at 10 minutes of the equilibrium was significantly higher in group III(72.1$\pm$5.3 mmHg p<0.01) and group III(72$\pm$5.6 mmHg P<0.025) as compared with group I (40.8$\pm$4.7mmHg) and LVDP at 20 minutes of the reperfusion was significantly higher in group II(74$\pm$5.3mmHg p<0.01) and group III(72$\pm$5.6mmHg p<0.025) as compared with group I (44.2$\pm$4.6mmHg). Percentage recovery of LVDP at the reperfusion was the highest in group II(123.3%) Percentage recovery of coronary flow at the equilibrium reperfusion were higher in group II(310%, 270%) group III(230%, 290%) group IV(310%, 280%) as compared with group I (100%) respectively. Myocadial LDH level was significant lower in group IV(33495$\pm$1802 IU/gm p<0.04) as compared with group I(48767$\pm$1421 IU/gm) Myocadial CK-MB level was significant higher in group II(74820$\pm$1421 IU/gm) compared with group I (45450$\pm$1737 IU/gm) Myocadial ADA level was significant higher group IV(1215$\pm$8 IU/gm p<0.05) compared with group I(125$\pm$15 IU/gm) but there was no significant difference between group I and group II ,III, IV in changes of coronary effluent LDH, a-HBD levels. Conclusion: C-AMP PDSI solely appears to have a better effect on myocardial preservation after ischemia than NBT but with no synergistic effect and it could keep CK-MB leve high in myocardial tissues.

  • PDF

Isolation, Identification, and Fermentation Characteristics of Bacillus sp. with High Protease Activity from Traditional Cheonggukjang (전통 청국장으로부터 protease 분비능이 우수한 Bacillus sp. 균주의 분리 동정 및 발효 특성)

  • Ahn, Yong-Sun;Kim, Yong-Suk;Shin, Dong-Hwa
    • Korean Journal of Food Science and Technology
    • /
    • v.38 no.1
    • /
    • pp.82-87
    • /
    • 2006
  • Twenty one strains strongly producing protease were isolated from Korean traditional Cheonggukjang. Eight strains selected by sensory evaluation on Cheonggukjang prepared with isolated strains were identified with based on biochemical properties a and 16S rDNA sequencing. Identified strains were Bacillus subtilis MB4, and Bacillus amyloliquefaciens A1, A2, B1, MC1, SB2, SC1, and SD1. Protease activities, important strain selection factor, were higher in Cheongjukjang prepared with B. subtilis MB4 (179.6 Unit) and B. amyloliquefaciens SB2 (201.9 Unit) than commercial traditional Cheonggukjang (97.9 Unit). Sensory evaluation revealed Cheonggukjang prepared with B. subtilis MB4 had flavor very similar to commercial traditional Cheonggukjang. Cheonggukjang prepared with B. suhtilis MB4 (0.0006 Pa s) and commercial traditional Cheonggukjang (0.0002 Pa s) revealed lower viscosities than those of Cheonggukjang prepared with B. amyloliquefaciens SB2, MC1, B1, A1, SD1, A2, and SC1 (0.006 to 0.008 Pa s at 1001/s. Results show Cheonggukjang could be prepared using single strain of B. subtilis MB4, maintaining high protease activity and very similar sensory and viscosity qualities with those of commercial traditional Cheonggukjang.

An Access Control Model for Privacy Protection using Purpose Classification (사용목적 분류를 통한 프라이버시 보호를 위한 접근제어 모델)

  • Na Seok-Hyun;Park Seog
    • Journal of the Korea Institute of Information Security & Cryptology
    • /
    • v.16 no.3
    • /
    • pp.39-52
    • /
    • 2006
  • Recently purpose is used by an crucial part to security management when collecting data about privacy. The W3C(World Wide Web Consortium) describes a standard spec to control personal data that is provided by data providers who visit the web site. But they don't say anymore about security management about personal data in transit after data collection. Recently several researches, such as Hippocratic Databases, Purpose Based Access Control and Hippocratic in Databases, are dealing with security management using purpose concept and access control mechanism after data collection a W3C's standard spec about data collection mechanism but they couldn't suggest an efficient mechanism for privacy protection about personal data because they couldn't represent purpose expression and management of purposes sufficiently. In this paper we suggest a mechanism to improve the purpose expression. And then we suggest an accesscontrol mechanism that is under least privilege principle using the purpose classification for privacy protection. We classify purpose into Along purpose structure, Inheritance purpose structure and Stream purpose structure. We suggest different mechanisms to deal with then We use the role hierarchy structure of RBAC(Role-Based Access Control) for flexibility about access control and suggest mechanisms that provide the least privilege for processing the task in case that is satisfying using several features of purpose to get least privilege of a task that is a nit of business process.

Moderating Effects of User Gender and AI Voice on the Emotional Satisfaction of Users When Interacting with a Voice User Interface (음성 인터페이스와의 상호작용에서 AI 음성이 성별에 따른 사용자의 감성 만족도에 미치는 영향)

  • Shin, Jong-Gyu;Kang, Jun-Mo;Park, Yeong-Jin;Kim, Sang-Ho
    • Science of Emotion and Sensibility
    • /
    • v.25 no.3
    • /
    • pp.127-134
    • /
    • 2022
  • This study sought to identify the voice user interface (VUI) design parameters that evoked positive user emotions. Six VUI design parameters that could affect emotional user satisfaction were considered. The moderating effects of user gender and the design parameters were analyzed to determine the appropriate conditions for user satisfaction when interacting with the VUI. An interactive VUI system that could modify the six parameters was implemented using the Wizard of OZ experimental method. User emotions were assessed from the users' facial expression data, which was then converted into a valence score. The frequency analysis and chi-square test found that there were statistically significant moderating gender and AI effects. These results implied that it is beneficial to consider the users' gender when designing voice-based interactions. Adult/male/high-tone voices for males and adult/female/mid-tone voices for females are recommended as general guidelines for future VUI designs. Future analyses that consider various human factors will be able to more delicately assess human-AI interactions from a UX perspective.

Middle School Home Economics Teachers' Recognition of the Importance and the Level of Teaching Performance regarding the Contents of Morality Education in Home Economics Instruction (중학교 가정과교사의 가정교과에서의 도덕성 교육에 대한 중요도와 지도수행 정도)

  • Cho Mi Ok;Chae Jung Hyun
    • Journal of Korean Home Economics Education Association
    • /
    • v.17 no.2
    • /
    • pp.257-272
    • /
    • 2005
  • The purpose of this study is to provide the basic data for morality of education in home economics education. Through research on the state of morality of education, the following criteria can be achieved ; recognition of the importance, and the level of teaching performance regarding the contents of morality education in home economics instruction. The basic data were obtained by looking at the differences between the recognized importance and the level of teaching performance. Data were collected from the survey mailed to the teachers responsible for home economics area in $\lceil$Technology${\cdot}$Home Economics$\rfloor$ in middle schools in Korea. The 335 questionnaires collected were used for final analysis. SPSS/WIN 10.0program was used for calculating and analysis the frequency, percentage, average. standard deviation. Firstly, most of the home economics teachers show that they continually try to implement morality education through each home economics lesson plan. They focus their attention on the main theme of the lesson of a particular nit, that deals with family life. For example, an excerpt from a particular unit may be the 'Understanding of myself and family members'. Most home economics teachers believe that a family setting and/or schools, whether private or public institutions, are appropriate places for productive education. As well, each of these educational settings, should take complete responsibility for teaching morality of education. As a way to activate the morality education, teachers believe that working with the students and understanding the needs of their students, along with the cooperation of parents, are key factors in the teaming process. Another way is the change of teacher's perceptions and educational conditions or environment. Secondly. home economics teachers in middle school. are showing a higher level of understanding on the importance regarding the contents of morality education, which can be noticed through the high level of their teaching performances. Regarding the importance of morality education, the first priority goes to showing respect for parents and the elderly, as well as sexual ethics and respect for life must always be taken into consideration. In regards to the level of teaching performance, the first priority goes to responsibility and co-operation. Secondly. showing respect for parents and the elderly and sexual ethics will be the third. Through data achieved through this study, the majority of home economics education teachers believe that morality education in home economics education is very important and a key factor in their teaching practices.

  • PDF

STUDY ON THE ANCHOVY BOAT SEINE 1. On the Hydrodynamic Resistance and Performance of the Conventional Gear (기선기현강의 연구 1, 재래식 어구의 유구저황과 그물꼴에 관하여)

  • LEE Byoung-gee;YANG Yong-rim;SU Young-tae;SON Boo-il
    • Korean Journal of Fisheries and Aquatic Sciences
    • /
    • v.4 no.3_4
    • /
    • pp.79-91
    • /
    • 1971
  • A boat seine has been used as a major fishing gear for catching anchovy (Engraulis japonica) in the southern coastal waters of Korea since 1920s. The original seine was operated by two rowing boats as the haul seine. The rowing boats were, in recent, replaced by powered boats. The net size was enlarged by more than three times the original nit as they began to by operated in the deeper waters of approximately sixty meters. However, there are many problems in the efficiency of the fishing gear to be improved. The authors studied on the hydrodynamic resistance and performance of the boat seine net of the 1/10 scale model in tow. The results are summaried as follows. 1. The hydrodynamic resistance converted from model experiment into the full scale is: $$R_1=30,000\;v^{1.2}\;(0.2{\leqq}v{\leqq}1.0)$$ $$R_2=16,000\;v^2\;(0.2{\leqq}v{\leqq}0.6)$$ where $R_1$ and $R_2$ denote the resistance of whole gear and of bag net in kg respectively, and v the speed of flow in m/sec. 2. In the extension wing, approximately seventy percent of the length of the ground rope from the towing end to the inside-wing slopes down from sea level toward the sea bottom, while the thirty percent of the inside of it remains parallel with th: 5:a level. The performance is regarded to b: inefficient for driving fish shoal into the inside-wing, especially for the shoal diving suddenly. 3. At the towing speed higher than 0.2 m/sec, the trailing edge of the inside-wing is blown backward beyond the seaming line connecting the inside-wing and the mouth of the bag net. It is regarded as an unreasonable performance to drive the fish shoal smoothly into the bag net. 4. At the towing speed higher than 0.2 m/sec, the posterior end of the lower bosom is lifted up above the level of the ground rope of the inside-wing. It is considered that the fish shoal diving suddenly can escape through the discrepancy between the lower bosom and the sea bottom, even if the ground rope of the inside-wing sweeps the sea bottom. 5. The angle of inclination of the upper bosom is estimated as $35\~40^{\circ}$. It seems that the inclination is too steep to drive smoothly the fish shoal diving toward the sea bottom into the bag net. 6. In structure, circumference of the posterior section of the bag net is wider by 1.3 times that of the anterior section. Actually in towing at a speed higher than 0.2m/sec, however, the circumference of the posterior section becomes smaller than that of the anterior section. It is recommended to be designed in a long cylindrical form.

  • PDF