• 제목/요약/키워드: HDI

검색결과 141건 처리시간 0.023초

고속액체크로마토그래피를 이용한 이소시아네이트의 동시 정량 (Simultaneous Determination of Isocyanates by High Performance Liquid Chromatography)

  • 이선주;이광묵;노영만
    • 한국산업보건학회지
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    • 제4권2호
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    • pp.137-147
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    • 1994
  • This study was designed to identify and quantitate airborne isocyanate simultaneously by HPLC. These samples were collected using 1-(2-pyridyl)piperazine(1-2PP) coated glass fiber filter from polyurethane painting works at 8 wood furniture factories in Kimpo and Inchun. The results obtained were as follows : 1. The most suitable mobile phase condition of simultaneously analyzing isocyanates was 0.01 M ammonium acetate buffer ACN(70/30) adjusted to pH 6.2 from the beginning of the analysis to 20 min and 0.01 M ammonium acetate buffer/ACN(50/50) adjusted to pH 6.2 from 21 min to 40 min using the gradient mode. The peaks of isocyanates were able to obtain within 30 min. 2. The recovery efficiencies for 2,6-TDI, 2,4-TDI, HDI and MDI urea derivates spiked at the target concentration on coated glass fiber tillers were 91.00, 93.42, 91.31 and 94.21 %, respectively. 3. The qualitative analysis of the isocyanates samples from polyurethane spray painting works in wood furnture factories identified Ihree isocyanates, 2,6-TDI, 2,4-TDI and MOI. And their concentration ranges were 0-312.6, 0-56.3 and $0-62.1{\mu}g/m^3$, respectively. A disadvantage of using the colorimetric method for isocyanate analysis is its inability of separating isocyanates. This study identified such three isocyanates as 2,6-TDI, 2,4-TDI and MDI from polyurethane spray painting works in wood furniture factories. These isocyanates were successfully quantitated by HPLC by modifying the mobile phase condition and switching to gradient mode.

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Gender and Social Disparities in Esophagus Cancer Incidence in Iran, 2003-2009: A Time Trend Province-level Study

  • Kiadaliri, Aliasghar Ahmad
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권2호
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    • pp.623-627
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    • 2014
  • Background: Esophagus cancer (EC) is among the five most common cancers in both sexes in Iran, with an incidence rate well above world average. Social rank (SR) of individuals and regions are well-known independent predictors of EC incidence. The aim of current study was to assess gender and social disparities in EC incidence across Iran's provinces through 2003-2009. Materials and Methods: Data on distribution of population at province level were obtained from the Statistical Centre of Iran. Age-standardized incidence rates of EC were gathered from the National Cancer Registry. The Human Development Index (HDI) was used to assess the province social rank. Rate ratios and Kunst and Mackenbach relative indices of inequality ($RII_{KM}$) were used to assess gender and social inequalities, respectively. Annual percentage change (APC) was calculated using joinpoint regression. Results: EC incidence rate increased 4.6% and 6.5% per year among females and males, respectively. There were no gender disparities in EC incidence over the study period. There were substantial social disparities in favor of better-off provinces in Iran. These social disparities were generally the same between males and females and were stable over the study period. Conclusions: The results showed an inverse association between the provinces' social rank and EC incidence rate in Iran. In addition, I found that, in contrast with international trends, women are at the same risk of EC as men in Iran. Further investigations are needed to explain these disparities in EC incidence across the provinces.

회전 디스크-스핀들, 액츄에이터와 지지구조의 유연성을 고려한 하드 디스크 드라이브의 고유 및 강제 진동 해석 (Free and Forced Vibration Analysis of a Hard Disk Drive Considering the Flexibility of Spinning Disk-Spindle, Actuator and Supporting Structure)

  • 서찬희;장건희;이호성
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2006년도 춘계학술대회논문집
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    • pp.660-665
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    • 2006
  • This paper presents a finite element method to analyze the free and forced vibration of a hard disk drive (HDD) considering the flexibility of a spinning disk-spindle with fluid dynamic bearings (FDBs), an actuator with pivot bearings, an air bearing between head-disk interface and the base with complicated geometry. Finite element equation of each component is consistently derived with the satisfaction of the geometric compatibility of the internal boundary between each component. The spinning disk, hub and FDBs are modeled by annular sector elements, beam elements and stiffness and damping elements, respectively. The actuator am, E-block, suspension and base plate are modeled by tetrahedral elements. The pivot bearing in the actuator and the air bearing between head-disk interfaces are modeled by the stiffness element with five degrees of freedom and the axial stiffness, respectively. A global matrix equation obtained by assembling the finite element equations of each substructure is transformed to a state-space matrix-vector equation, and both damped natural frequencies and modal damping ratios are calculated by solving the associated eigenvalue problem with the restarted Arnoldi iteration method. Modal and shock testing are performed to show that the proposed method well predicts the vibration characteristics of a HDD.

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Synthesis of Novel Polythiol for Plastic Optical Lens and its Ophthalmic Lens

  • Jang, Dong-Gyu;Roh, Soo-Gyun;Kim, Jong-Hyo;Jin, Wen-Yi;Seo, Jin-Moo;Kwon, Myeong-Ja;Lee, Soo-Min
    • Bulletin of the Korean Chemical Society
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    • 제30권10호
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    • pp.2227-2232
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    • 2009
  • Novel polythiol materials of urethane lens series for plastic optical lens were synthesized from polyol materials via thioisouronium of thiourea with c-HCl in refluxing aqueous solution, in which polythiol material was carried out from hydrolysis of thioisouronium by ammonia water. Their structure properties were identified by EA, EI-MS, FT-IR, $^1H\;and\;^{13}C$ NMR spectroscopies and TGA. Their ophthalmic lenses as polythiourethane material were prepared by thermal curing to an injected glass mold using the evenly solutions of diisocyanates series (TDI, XDI, HDI or IPDI) with polythiols. Polythiourethane shows that the strong stretching mode for SH group of polythiol disappeared in FT-IR spectra after thermosetting polymerization. Thermal deformation starting temperature of ophthalmic lenses was determined by TMA. Ophthalmic lenses made from characteristic polythiol and diisocyanate series have transparency, colorless and good impact strength, in which thermal resistance and impact strength of ophthalmic lenses were influenced by diisocyanate series. Physical properties of ophthalmic lens have contrast thermal resistance with impact strength. The property of thermal resistance and impact strength for respective ophthalmic lenses was examined by TMA and drop ball test.

Study for the Availability of Ultrasonogram Guided Fine Needle Aspiration for Patients with Thyroid Gland Disease

  • Kim, Han-Yong;Dong, Kyung-Rae
    • International Journal of Contents
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    • 제5권1호
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    • pp.33-36
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    • 2009
  • Since the diagnosis of malignancy and benign of thyroid gland diseases is difficult only by using ultrasonogram opinions, the combination of fine needle aspiration (FNA) has been generalized trend for precise pathological diagnosis. Therefore, the current study aimed to know about its availability. The study subjected 500 patients who received the FNA along with the ultrasonogram screening for thyroid gland from October, 2007 to April, 2008. As the equipments for the study, Philips HDI-3500 and Philips UITRAMARKer-9 (UM-9) were used to conduct the comparative analysis of pathological results that were obtained through the inspection of ultrasonogram screening and through ultrasonogram guided FNA. Among the 464 patients who were found to be benign from the ultrasonogram screening inspection, II cases of the FNA diagnosis results judged to be malignancy, and 13 cases of the FNA diagnosis resulted to be benign among 36 patients who were diagnosed to be malignancy. The cases observed as solid from the opinions of ultrasonogram screening were often found to be malignancy, and most of the malignancy results were observed to show the hypoechoic pattern. Among the patients diagnosed with malignancy from the diagnosis of FNA, the 32 patients were found to have the papillary carcinoma, and the benign type was observed to be goiter and hyperplasia in 263 patients, which took up 52.6%. The ultrasonogram screening test that is performed for the purpose of diagnosing thyroid gland diseases, it is distinctively an useful inspection to diagnosis the presence, size and shape of nodules. However, the results of performing of FNA for those of nodules which were observed to be benign from the ultrasonogram were often came up with malignancy and there were cases that the nodules diagnosed with malignancy were diagnosed as benign from the FNA diagnosis.

Understanding the Current State of Deep Learning Application to Water-related Disaster Management in Developing Countries

  • Yusuff, Kareem Kola;Shiksa, Bastola;Park, Kidoo;Jung, Younghun
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2022년도 학술발표회
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    • pp.145-145
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    • 2022
  • Availability of abundant water resources data in developing countries is a great concern that has hindered the adoption of deep learning techniques (DL) for disaster prevention and mitigation. On the contrary, over the last two decades, a sizeable amount of DL publication in disaster management emanated from developed countries with efficient data management systems. To understand the current state of DL adoption for solving water-related disaster management in developing countries, an extensive bibliometric review coupled with a theory-based analysis of related research documents is conducted from 2003 - 2022 using Web of Science, Scopus, VOSviewer software and PRISMA model. Results show that four major disasters - pluvial / fluvial flooding, land subsidence, drought and snow avalanche are the most prevalent. Also, recurrent flash floods and landslides caused by irregular rainfall pattern, abundant freshwater and mountainous terrains made India the only developing country with an impressive DL adoption rate of 50% publication count, thereby setting the pace for other developing countries. Further analysis indicates that economically-disadvantaged countries will experience a delay in DL implementation based on their Human Development Index (HDI) because DL implementation is capital-intensive. COVID-19 among other factors is identified as a driver of DL. Although, the Long Short Term Model (LSTM) model is the most frequently used, but optimal model performance is not limited to a certain model. Each DL model performs based on defined modelling objectives. Furthermore, effect of input data size shows no clear relationship with model performance while final model deployment in solving disaster problems in real-life scenarios is lacking. Therefore, data augmentation and transfer learning are recommended to solve data management problems. Intensive research, training, innovation, deployment using cheap web-based servers, APIs and nature-based solutions are encouraged to enhance disaster preparedness.

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클로닝된 Bacillus thuringiensis subsp. kurstaki HDI 살충성 단백질 유전자의 대장균에서의 발현 (Expression in Eschepichia coli of a Cloned Bacillus thuringiensis subsp. kurstaki HDI In-secticidal Protein Gene.)

  • 황성희;차성철;유관희;이형환
    • 한국미생물·생명공학회지
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    • 제26권6호
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    • pp.497-506
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    • 1998
  • Bacillus thurintensis subsp. kurstaki HD1 살충성 단백질 ICP 유전자가 있는 NdeI 단편 3.856 kb를 클로닝하여 제조한 pHLN2-80(-) 클론이 pHLN1-80(-)에 비해서 대장균에서 ICP발현량이 과다발현되는 현상을 규명하고자 하였다. 본 연구에서는 상기의 pHLN2-80(+) 클론의 발현량을 조절하는 원인을 규명하기 위하여 ICP의 아미노산 서열은 변화되지 않는 범위 내에서 pHLN1-80(+) 클론에 있는 Plac프로모터와 ICP유전자 프로모터의 일부인 -80 bp프로모터의 염기서열, 전사 개시점과 종결부위의 변이가 ICP유전자발현에 미치는 영향을 조사하였다. pHLN1-80(+)에 5'-말단에 존재하는 -80 bp 프로모터만을 보유한 pHLNK-80 클론은 ICP 생산은 매우 저조하였다. Plac프로모터와 -80 bp 프로모터의 구조 골격을 일부 변이 시킨 pHLNF1-80클론의 ICP생산량은 pHLN2-80(-)가 생산한 양보다는 낮아서 과다발현이 안되었다. Plac프로모터 상류를 약 350bp을 제거하여 만든 클론 pHLND2-80의 ICP 생산량은 모클론인 pHLN2-80(-) 보다 매우 높게 과다발현 되었다. ICP 유전자의 과다발현 현상에 대한 전사 개시점과 전사종결 부위의 역할을 알아보기 위해서 -72bp ICP유전자프로모터를 갖는 클론 pHLD1-72는 재조합 클론 pHLN2-80(-)가 생산한 양보다 적은 양의 ICP을 생성하였고, 클론 pHLD2-72는 재조합 클론 pHLN2-80(-)보다 적은 ICP을 발현하여 과다 발현되었으며, 클론 pHLN2-72는 모클론인 pHLN2-80(-)보다 약간 높은 ICP 생산량을 보여 과다발현되었다. 클론 pHLN2-72를증식하여 파쇄액을 만든 후에 Bombyx mori유충에 대한 살충력 검사에서 클론 pHLN2-72이 생산한 ICP는 pHLN1-80(+)이 생산한 ICP보다 약 90배의 살충력을 보였다. SDS-PAGE와 Western blot 분석에서도 클론 pHLN2-72는 재조합 클론 pHLN2-80(-)보다 약간 높게 ICP가 생성이 되었었다. 이상의 결과는 과다발현에 Plac프로모터와 종결부위가 반드시 필요하며, -72 bp ICP 프로모터가 -80 bp 프로모터보다 과다발현률이 높았으며, ICP 유전자는 반드시 Plac프로모터의 전사 방향에 역방향으로 삽입이 되어야 하는 것으로 나타났다.

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만성 긴장성 두통 환자에 대한 사암침 치료효과의 Pilot 임상연구 (Effect of Sa-am Acupuncture Method for Chronic Tension-type Headache;A Randomized Controlled Trial)

  • 홍권의;박양춘;조정효;조현경;정인철;강위창;이상봉;최선미
    • Journal of Acupuncture Research
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    • 제24권1호
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    • pp.13-28
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    • 2007
  • Objectives : Clinical character of chronic tension-type headache is bilateral, moderate intensity, persistent and chronic, repeating disease and CTTH is a common prevalent disease, but pathophysiology and likely mechanism remain unclear. It impedes subjective quality of life. The purpose of this research is to examine the effect of sa-am acupuncture method for chronic tension-type headache. Methods : In this randomized, single blind, placebo-controlled study, we compared active acupuncture with sham acupuncture for the treatment of chronic tension-type headache. Volunteers who satisfied the requirements were enrolled in study. Evaluation of chronic tension-type headache was measured by VAS and Headache Disability Inventory(HDI), Six point Linkert Scale before and after treatments. Results : 26 subjects finished study. There were not difference between two groups on age, sex, weight, height, blood pressure, pulse, respiratory rate, Byeonjeung, sunrise of treatment. In change of VAS, there were not difference between two groups on before treatment. Before treatment per visit, VAS of 6th and 7th visit were significantly decreased in active acupuncture(each p=0.039, p=0.008) and were not decreased in sham acupuncture. In change of VAS on a withdrawing needling after treatment, VAS of 1st, 2nd, 6th and 7th visit were significantly decreased in active acupuncture (each p=0.001, 0.038, 0.035, 0.008) and VAS of 2nd, 4th and 5th, 6th visit were significantly decreased in sham acupuncture(each p=0.033, 0.032, 0.035, 0.031). In change of VAS on 2hrs after treatment, VAS of 4th and 5th, 6th visit were significantly decreased in active acupuncture(each p=0.014, 0.023, 0.027) and 5th visit were significantly decreased in sham acupuncture(each p=0.004, 0.009). In change of VAS on 4hrs after treatment, VAS of 4th and 5th, 6th visit were significantly decreased in active acupuncture(each p=0.018, 0.011, 0.015) and 5th, 6th visit were significantly decreased in sham acupuncture(each p=0.020, 0.015). In change of VAS on the next day after treatment, VAS of 3th and 4th and 5th, 6th visit were significantly decreased in active acupuncture(each p=0.032, 0.011, 0.005, 0.012) and 4th, 5th visit were significantly decreased in sham acupuncture(each p=0.001, 0.012). In change of VAS according to a current time(before treatment, after a withdrawing needling, 2hrs, 4hrs, the next day), total score of VAS was decreased more active acupuncture group than sham acupuncture group, but there were no statistical significance compared with sham acupuncture group. In change of HDI score, after treatment was decreased than before treatment in two group, but there were no statistical significance compared with two group. In change of Six point Linkert scale score, after treatment was decreased than before treatment in two group on 6th, 7th visit(active acupuncture 6th 7th each p=0.002, 0.003, sham acupuncture 6th 7th each 0.003, 0.009), but there were no statistical significance compared with tow group. Conclusion : Sa-am acupuncture treatment is effective to improve the symptoms and quality of life in patients with chronic tension-type headache.

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중학교 지리 교과서에 재현된 개발 담론 분석 (Development Discourse and Its Representation in Middle School Geography Textbooks)

  • 조철기
    • 한국지역지리학회지
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    • 제20권4호
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    • pp.454-472
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    • 2014
  • 이 연구는 개발 담론의 변화에 대한 고찰을 통해 우리나라 중학교 지리교육과정 및 지리교과서에 재현된 개발 담론의 특징을 분석한 것이다. 개발 담론은 근대화이론, 종속이론, 신자유주의, 풀뿌리 개발, 지속가능한 개발, 탈식민주의 탈구조주의 관점에서 살펴보았다. 이에 근거하여 지리교과서에 재현된 개발담론을 분석하였는데. 그 결과는 다음과 같다. 첫째, 개발 및 지속가능한 개발에 대한 개념 정립과 조작적 정의가 부족한 것으로 나타났다. 둘째, 개발의 척도는 주로 1인당 국내총생산 또는 1인당 국민총소득과 같은 평균적인 경제적 척도에 의존하고 있었다. 교육수준과 평균수명을 포함한 인간개발지수는 일부 교과서에서만 언급되고, 젠더 지수는 전혀 언급하고 있지 않았다. 셋째, 특정 교과서는 개발도상국 대신에 편견적인 저개발국, 최저개발국이라는 용어를 여전히 사용하고 있었다. 넷째, 경제적 불평등 및 지리적 문제 해결을 위한 방안에서는 국제적, 국가적, 비정부조직의 차원에 대한 강조에 비해 개인적 측면에 대한 고려가 매우 부족한 것으로 나타났다. 마지막으로, 지속가능한 개발 있어서 세대 간 공정만 언급할 뿐 세대 내 공정은 간과하고 있다. 그리고 지속가능한 개발에 대한 접근은 주로 생태중심적 접근보다는 기술중심적 접근에 토대하고 있다. 이상과 같은 결과를 통해 볼 때, 지리교과서 서술에 있어서 개발 담론에 대한 더욱 더 신중한 접근이 요구된다고 할 수 있다.

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인과 염소 함유 변성폴리에스터/이소시아네이트 가교 폴리머의 PU 난연도료에의 적용 (Application of Isocyanate and Modified Polyester Containing Phosphorous and Chlorine to Crosslinked PU Flame-Retardant Coatings)

  • 박홍수;김송형;안성환;유규열;함현식
    • 한국응용과학기술학회지
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    • 제24권2호
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    • pp.124-139
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    • 2007
  • In order to obtain the maximum flame retardancy with the minimal deterioration of physical properties of PU flame-retardant coatings, chlorine and phosphorous functional groups were introduced into the pre-polymer of modified polyesters. In the first step, the tetramethylene bis(orthophosphate) (TBOP) and neohexanediol dichloroacetate (DCA-adduct) intermediates were synthesized. In the second step, 1,4-butanediol and adipic acid monomers were polymerized with the two kind of intermediates to obtain copolymer. The modified polyesters containing chlorine and phosphorous (ATBA-10C, -20C, and -30C) were synthesized by adjusting the contents of chlorine compound (dichloroacetic acid, 10, 20, 30 wt%) with fixed the content of phosphorous compound (2 wt%). The PU flame-retardant coatings (TTBAH -10C, -20C, and -30C) were prepared using the synthesized ATBAs and HDI-trimer as curing agent at room temperature. The physical properties of PU flame-retardant coatings with chlorine and phosphorous were inferior to those with phosphorous only and the properties were getting worse with increasing chlorine content. Flame retardancy was tested with three methods. With the vertical method, Complete combustion time of ATBAHs were $259^{\sim}347$ seconds, which means that the prepared coatings are good flame-retardant. With the $45^{\circ}$ Meckel burner method, char lengths of the three prepared coatings were less than 2.9 cm, which indicates that the prepared coatings are 1st grade flame retardancy. With the limiting oxygen index (LOI) method, the LOI values of the three prepared coatings were in the range of $30^{\sim}35%$, which proves good flame retardancy of the prepared coatings. From the results of flame retardancy tests of the specimens that contain the same amounts of flame retarding compounds, it was found that the coatings containing both phosphorous and chlorine show higher flame retardancy than the coatings containing phosphorous alone. This indicates that some synergy effect of flame retardancy exists between phosphorous and chlorine.