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A Study on The Evalution of Influencing Factors in THM Analysis (THM 분석에 있어서의 영향인자에 관한 연구)

  • 남상호;이운기
    • Journal of Environmental Health Sciences
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    • v.18 no.2
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    • pp.82-91
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    • 1992
  • The examination of the pollutants originated from domestic sewage, industrial and agricutural activities the existences of some toxic heavy metals, organic matters and pathogenic microorganisms. A recent report of WHO brought out that such pollutants are in existence with above roughly 2,000 kinds of chemical substances and amongst them about 750 chemicals have been indentified by drinking water. And above 600 kinds of them are organic pollutants and in addition these include carcinogenic mutagenic and poisonous substances. This is not intended to embody a study of broad confined to various approaches on organic materials, and therefore will be THM produced on injection of chlorine at water filtration plant. To specify the relations between THM and factors having an effect upon THM such as TOC, Cl$_{2}$, Temperature, pH and reaction time, first of all the recovery ratio for analytical methods of THM (Head sapce, purge and trap, Liquid/ Liquid Extraction methods) was investigated. Provided that by using it,the correction coefficients are obtained, the accuracy of data might be able to be enhanced through analysis.The result of the experiments are given in the followings. 1) Among three kinds of analytical methods, recovery rate was higher in order of purge and trap Liquid/Liquid Extraction, Head space. There is no great difference in recovery rate among three methods. 2) The higher the concentration of TOC, the more the amount of THM. 3) The higher the reaction temperature, the more the amount of THM. 4) The longer the reaction time, the more the amount of THM. 5) The higher the pH, the more the amount of THM. 6) The higher the concectration of chlorine, the more the amount of THM.

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Study on Virtual Reality (VR) Operating System Prototype (가상환경(VR) 운영체제 프로토타입 연구)

  • Kim, Eunsol;Kim, Jiyeon;Yoo, Eunjin;Park, Taejung
    • Journal of Broadcast Engineering
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    • v.22 no.1
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    • pp.87-94
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    • 2017
  • This paper presents a prototype for virtual reality operating system (VR OS) concept with head mount display (HMD) and hand gesture recognition technology based on game engine (Unity3D). We have designed and implemented simple multitasking thread mechanism constructed on the realtime environment provided by Unity3D game engine. Our virtual reality operating system receives user input from the hand gesture recognition device (Leap Motion) to simulate mouse and keyboard and provides output via head mount display (Oculus Rift DK2). As a result, our system provides users with more broad and immersive work environment by implementing 360 degree work space.

Development of a Submerged Propeller Turbine for Micro Hydro Power

  • Kim, Byung-Kon
    • The KSFM Journal of Fluid Machinery
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    • v.18 no.6
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    • pp.45-56
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    • 2015
  • This paper aims to develop a submerged propeller turbine for micro hydropower plant which allows to sustain high values of efficiency in a broad range of hydrological conditions (H=2~6 m, $Q=0.15{\sim}0.39m^3/s$). The two aspects to be considered in this development are mechanical simplicity and high-efficiency operation. Unlike conventional turbines that have spiral casing and gear box, this is directing driving and no spiral casing. A 10 kW class turbine which has the most high potential of the power generation has been developed. The most important element in the design of turbine is the runner blade. The initial blade is designed using inverse design method and then the runner geometry is modified by classical hydraulic method. The design process is carried out in two steps. First, the blade shape is fix and then other components of submerged propeller turbine are designed. Computational fluid dynamics analyses based on the Navier-Stokes equations have been used to obtain overall performance data for the blade and the full turbine, respectively. The results generated by performance parameters(head, guide vane opening angle and rotational speed) variations are theoretically analysed. The evaluation criteria for the blade and the turbine performances are the pressure distribution and flow's behavior on the runner blades and turbine. The results of simulation reveals an efficiency of 91.5% and power generation of 10.5kW at the best efficiency point at the head of 4m and a discharge of $0.3m^3/s$.

Tegumental Ultrastruetures of Echinostoma hoytense observed by Scanning Electron Microscopy (Echinostoma hortense 표피의 주사전자현미경적 관찰)

  • 이순형;홍성종
    • Parasites, Hosts and Diseases
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    • v.24 no.1
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    • pp.63-70
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    • 1986
  • The tegumental ultrastructures oi Echinostoma hortense adults were observed by scanning electron microscopy. The worms of 4 weeks of age were harvested from albino rats experimentally infected with the metacercariae obtained from the loach. The results were as follows: 1. The worms were leaf-like and their anterior end portion, including oral sucker and head crown, ventrally curved to face posteriorly. The tegument of whole body was wrinkled transversely and covered with cobblestone-like cytoplasmic processes. 2. The oral sucker had roundly swollen (type I ) sensory papillae on the ventral half of its lip and mini-ciliated knob-like (type I ) sensory papillae, arranged in 2∼3 rows, on the dorsal outer surface. 3. Aspinous ventral sucker had many of type I papillae arranged in a circular band on its outer surface. The tegument around the genital opening was of similar feature to the ventral sucker, but sensory papillae were hardly found around the former. 4. Scale-like spines with broad base and round tip were distributed densely on the tegument anterior to the ventral sucker but they became sparse in posterior half of the ventral surface, finally to disappear at posterior extremity. A few number of type I papillae were observed on the ventral surface. The results suggest that the tegument of 5. hortense is similar to that of other echinostomes etapecially 5. revolutum. But the number and arrangement of collar spines, and/or the type and distribution of sensory papillae seem characteristic features of E. hortense differed from other echinostomes.

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Effect of Olive Flounder, Paralichthys olivaceus, Immune Genes Stimulation by Molecular Adjuvant in Vitro Culture Condition (In vitro 조건에 따른 molecular adjuvant의 넙치, Paralichthys olivaceus 면역유전자 자극 효과)

  • KWON, Mun-Gyeong;Hwang, Jee-Youn;SEO, Jung-Soo;JUNG, Sung-Hee
    • Journal of Fisheries and Marine Sciences Education
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    • v.27 no.5
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    • pp.1470-1478
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    • 2015
  • Adjuvant is an immune enhancer commonly used during vaccination to enhance the host immune response. In the present study, we produced the several recombinant protein from immune related gene of olive flounder (Paralichthys olivaceus). Especially, to produce the soluble type of recombinant protein, we constructed the MBP (Maltose binding protein) fusion G-CSF (Granulocyte colony stimulating factor) recombinant protein among the flounder immune related genes. To verify the immune stimulatory effect and safety of this recombinant protein (rPoGCSF), expression changes of several immune genes were tested using quantitative real-time PCR method with gene specific primer from flounder head kidney leukocytes. As a result, we confirmed that the rPoGCSF has an ability of immune stimulatory effect, also it has broad range of pH and temperature.

Characteristics of Cytosolic Calcium-Independent Phospholipase $A_2$ Isolated from Rat Liver

  • Won, Jong-Hak;Na, Doe-Sun;Rhee, Hae-Jin;Park, Young-Min
    • BMB Reports
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    • v.32 no.2
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    • pp.154-160
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    • 1999
  • A calcium-independent phospholipase $A_2$ ($iPLA_2$) was identified from the cytosolic fraction of rat liver cells. On gel filtration chromatography, the $iPLA_2$ activity was eluted as broad peaks of 150 to 500 kDa. The enzyme was maximally active at pH 7.5, retained 75% of its original activity after heating at $50^{\circ}C$ for 5 h, and was inhibited by $Ca^{2+}$, $Mg^{2+}$, and $Zn^{2+}$ ions, but was not affected by $Na^+$ and $K^+$ ions. The enzymatic activity was increased up to 150% by 1 to 4 mM DTT and was inhibited up to 25% by 0.1 to 1 mM PMSF. The $iPLA_2$ activity had preference for the head group of phospholipids, where phosphatidylethanolamine was preferred to phosphatidylcholine. The results suggest that the $iPLA_2$ may be a novel enzyme distinct from the previously reported $iPLA_2s$.

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Mixed Reality System for Virtual Chemistry Lab

  • Duan, Xiaoyun;Kang, Shin-Jin;Choi, Jong In;Kim, Soo Kyun
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.14 no.4
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    • pp.1673-1688
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    • 2020
  • This paper presents a new method for improving teaching aids with the design and development of a chemistry education platform - the Mixed Reality (MR) Chemistry Lab. Our system provides a new educational experience in which students can simulate a chemistry experiment in a virtual lab and interact with objects using Oculus Helmet-Mounted Displays (HMD) and hand controller devices. The proposed system aims to familiarize students with experimental procedures and safety knowledge before conducting actual experiments. Moreover, students will be able to observe microscopic atomic structure models in three dimensions. Our research also includes a five-part, quantitative evaluation system user tests perform using a quantitative questionnaire consisting of five items, including hardware equipment, immersion, education, interaction sense of control, and degree of difficulty. The evaluation results confirm that this system will be helpful to the educational experience of conducting chemistry experiments with scientific evaluation methods, and the proposed system is also expected to have a broad range of applications in many other subjects.

Species Distribution and Characteristics of Wild Mice in Mt. Keumwon Recreational Forests (금원산 자연휴양림 내 들쥐류의 종 분포 및 특성)

  • Lee, Chong Kyu;Kang, Young Min
    • Journal of Forest and Environmental Science
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    • v.30 no.1
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    • pp.161-166
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    • 2014
  • To provide basic information for wildlife management, we investigated the distribution and ecology of wild mice in Mt. Keumwon recreational forests. The trapped wild mice were a total of 4 species such as Eothenomys regulus, Apodemus speciosus peninsulae, Apodemus agarius, and Crocidura suaveolens. A total of 79 individuals from four species were trapped. Number of Eothenomys regulus was the highest as 41 individuals followed by Apodemus speciosus peninsulae of 31 individuals, Apodemus agarius of 4 individuals, and Crocidura suaveolens of 4 individuals. Depending on forest type, 51 individuals were captured in broad-leaved forests, whereas 28 individuals were captured in coniferous forests. Average weight of the trapped Eothenomys regulus, Apodemus speciosus peninsulae, Apodemus agarius, and Crocidura suaveolens was 37.13 g, 36.29 g, 31.25 g, and 15 g, respectively. Among the trapped wild mice, vole which has the largest head and ears were Eothenomys regulus and vole which has the longest tail was Apodemus speciosus peninsulae and Apodemus agarius (p<0.5). This study might be valuable to control and predict some damages related to wild mice in Mt. Keumwon for protecting forest trees.

Misdiagnosis of fetus-in-fetu as meconium peritonitis

  • Kim, Yoon-Joo;Sohn, Se-Hyung;Lee, Ju-Young;Sohn, Jin-A;Lee, Eun-Hee;Kim, Ee-Kyung;Choi, Chang-Won;Kim, Han-Suk;Kim, Beyong-Il;Choi, Jung-Hwan
    • Clinical and Experimental Pediatrics
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    • v.54 no.3
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    • pp.133-136
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    • 2011
  • Fetus-in-fetu (FIF) is a rare congenital condition in which a fetiform mass is detected in the host abdomen and also in other sites such as the intracranium, thorax, head, and neck. This condition has been rarely reported in the literature. Herein, we report the case of a fetus presenting with abdominal cystic mass and ascites and prenatally diagnosed as meconium pseudocyst. Explorative laparotomy revealed an irregular fetiform mass in the retroperitoneum within a fluid-filled cyst. The mass contained intestinal tract, liver, pancreas, and finger. Fetal abdominal cystic mass has been identified in a broad spectrum of diseases. However, as in our case, FIF is often overlooked during differential diagnosis. FIF should also be differentiated from other conditions associated with fetal abdominal masses.

Effect of raft and pile stiffness on seismic response of soil-piled raft-structure system

  • Saha, Rajib;Dutta, Sekhar C.;Haldar, Sumanta
    • Structural Engineering and Mechanics
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    • v.55 no.1
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    • pp.161-189
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    • 2015
  • Soil-pile raft-structure interaction is recognized as a significant phenomenon which influences the seismic behaviour of structures. Soil structure interaction (SSI) has been extensively used to analyze the response of superstructure and piled raft through various modelling and analysis techniques. Major drawback of previous study is that overall interaction among entire soil-pile raft-superstructure system considering highlighting the change in design forces of various components in structure has not been explicitly addressed. A recent study addressed this issue in a broad sense, exhibiting the possibility of increase in pile shear due to SSI. However, in this context, relative stiffness of raft and that of pile with respect to soil and length of pile plays an important role in regulating this effect. In this paper, effect of relative stiffness of piled raft and soil along with other parameters is studied using a simplified model incorporating pile-soil raft and superstructure interaction in very soft, soft and moderately stiff soil. It is observed that pile head shear may significantly increase if the relative stiffness of raft and pile increases and furthermore stiffer pile group has a stronger effect. Outcome of this study may provide insight towards the rational seismic design of piles.