• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.31 no.3
• /
• pp.330-342
• /
• 1998

Benthic environmental parameters were analysed at 40 stations during the period from April 1995 to February 1996. such as water temperature, salinity, and dissolved oxygen (DO)-concentration in the surface and bottom water layers, grain size, chemical oxygen demand (COD), ignition loss, particulate organic carbon (POC) in the sediment of Youngsan River estuary. The water temperature ranged from 4.1 to $29.8^{\circ}C$ in the surface and 4.0 to $20.7^{\circ}C$ in the bottom layers. Salinity ranged from 15.1 to $33.6\%_{\circ}$ in the surface and 31.5 to $33.2\%_{\circ}$ in the bottom layer. The salinity in the outer pan of the study area was higher than that of inner area from autumn to spring, whereas they remained lower in summer. Dissolved oxygen concentration ranged from 5,1 to 11.2 $mg/\ell$ in the surface, and 0.79 to 10,2 $mg/{\ell}$ in the bottom layers. Hypoxic condition ($\le2.0mg/\ell$) was developed in the bottom water layer from Youngsan dike to Mokpo Harhour in summer due to the summer stratification. The surface sediment type was silty clay with a mean grain size of $9.12{\pm}0.45\phi$. The range of COD was from 6.15 to $15.49mgO_2/g$ with a mean of $10.59{\pm}12.64mgO_2/g$. The COD in the inner stations was relatively higher than that of outer stations, and decreased toward the outer part of the study area. Ignition loss (IL) ranged from 3.35 to $15.45\%$ with a mean of $5.96{\pm}1.91\%$. Principal component analysis was carried out from the following five environmental parameters: water temperature, dissolved oxygen in the bottom layer and mean grain size, clay content and COD in the sediment. The forty stations in the study area were classified into three stational groups. Group I was located in the inner part of the estuary characterised by relatively low surface salinity and bottom water temperature, fine sedimemt texture, high organic matter and low dissolved oxygen concentration during the summer. Meanwhile, Group III showing relatively high bottom salinity and water temperature was located in the outer part of the estuary characterising coarse sediment and low organic content in sediment. Group II was between Group I and Group III. The division of the areal groups had high correlations to the DO in the bottom layer and clay content in the sediment.

• Tuberculosis and Respiratory Diseases
• /
• v.52 no.4
• /
• pp.346-354
• /
• 2002

Background : Dyspnea and a limitation in exercise performance are important cause of disability in patients with chronic obstructive pulmonary disease(COPD). A depleted nutritional state is a common problem in patients with a severe degree of chronic airflow limitation. This study was carried out to assess the factors determining the maximum exercise capacity in patients with COPD. Methods : The resting pulmonary function, nutritional status, and maximum exercise performance was assessed in 83 stable patients with moderate to severe COPD. The nutritional status was evaluated by bioelectrical impedance analysis. Maximum exercise performance was evaluated by maximum oxygen uptake($VO_2max$). Results : Among the 83 patients, 59% were characterized by nutritional depletion. In the depleted group, a significantly lower peak expiratory flow rate(p<0.05), Kco(p<0.01) and maximum inspiratory pressure(p<0.05), but a significantly higher airway resistance(p<0.05) was observed. The maximum oxygen uptake and the peak oxygen pulse were lower in the depleted group. The $VO_2max$ correlated with some of the measures of the body composition : fat-free mass(FFM), fat mass(FM), body mass index(BMI), intracellular water index(ICW index), and pulmonary function : forced vital capacity(FVC), forced inspiratory vital capacity(FIVC), diffusion capacity(DLCO) : or maximum respiratory pressure : maximum inspiratory pressure(PImax), maximum expiratory pressure(PEmax). Stepwise regression analysis demonstrated that the FFM, DLCO and FIVC accounted for 68.8% of the variation in the $VO_2max$. Conclusion : The depletion of the FFM is significant factor for predicting the maximum exercise performance in patients with moderate to severe COPD.

• Proceedings of the Optical Society of Korea Conference
• /
• 2000.02a
• /
• pp.320-321
• /
• 2000

전기장 발광현상(Electroluminescence, 이하 EL)은 1936년 Destriau$^{[1]}$ 가 ZnS:Cu 분말에서 처음 전기장 발광현상을 발견한 이래 TFEL(Thin Film EL)소자의 구동전압을 감소시키는 문제는 ACTFEL(Alternating Current Thin Film EL)소자의 개발이후 계속적인 관심의 대상이 되어왔다. TFEL 소자는 전기적으로 용량소자이므로 전기장 인가시 각 층의 정전용량의 역수에 비례하는 전압이 분배되므로 동일한 조건의 형광막 사용시 소자의 구동전압을 낮추기 위해서는 절연박막의 두께를 줄이는 방법과 유전율이 높은 물질을 사용하는 방법이 있으나, 전자의 경우에는 박막의 결함이 생기기 쉬워 한계가 있기 때문에 고유전율 특성을 갖는 새로운 물질을 개발하는 것이 바람직하다. Ta$_2$O$_{5}$ 박막의 경우 작은 누설전류 특성과 고유전율 특성으로 인해 고집적을 요하는 반도체 분야에서 많은 연구가 진행되어 왔다. 또한 EL소자 응용시 효율면에서 우수한 특성이 기대되며, 특히 수분에 강한 특성을 가지고 있어 EL소자의 안정성이 예견되는 바이다. 본 연구에서는 Ta$_2$O$_{5}$ 박막의 산소 결핍에 따른 전기적 특성에 대해 연구하였고 Ta$_2$O$_{5}$ 박막을 이용한 저전압에서 구동가능한 전기장 발광소자를 제작하여 전기광학적 특성에 대해 연구하였다. (중략

• Journal of the Korean Society of Safety
• /
• v.30 no.6
• /
• pp.117-121
• /
• 2015

$O_2$-deficiency related accidents occur every year and the most effective way to prevent them is to measure $O_2$ concentration in air with a properly-calibrated $O_2$ monitoring device before entering low-$O_2$ areas. An electro-chemical sensor, Texas Instrument gas platform, and iPhone are used to construct a smartphone-based $O_2$ monitoring device. The smartphone based $O_2$ measuring approach offers advantages of small size, accessibility, internet-connectivity, and programmability in comparison to conventional $O_2$ measuring devices. Multiple gas sensors can be conveniently interfaced to single smartphone, allowing for creating a network of gas sensors distributed across workplaces and remote monitoring via existing mobile communication network. To check proper function of the $O_2$ monitoring device the sensor was exposed to shallow and deep human breaths. The readings decreased immediately after being exposed to exhalation and recovered during inhalation to a calibrated level of 20.9%. When readings decreased below a preset warning value of 19.5%, a low $O_2$ warning was successfully activated on the smartphone.

• Journal of Powder Materials
• /
• v.13 no.6 s.59
• /
• pp.401-407
• /
• 2006

Effects of oxygen deficiency on the room temperature ferromagnetism in Fe-doped reduced $TiO_2$ have been investigated by comparing the air-annealed $Ti_{0.97}Fe_{0.03}O_2$ compound with secondly post-annealed one in vacuum ambience. The air-annealed sample showed a paramagnetic behavior at room temperature. However, when the sample was further annealed in vacuum, a strongly enhanced ferromagnetic behavior was observed at same temperature. $M{\"{o}}ssbauer$ spectra of air-annealed sample at 295K showed a single doublet of $Fe^{3+}$, suggesting that the Fe ions are paramagnetic. On the other hand, the absorption spectra after vacuum-annealing exhibited two doublets, in which one is the same component with air-annealed sample and the other is new doublet corresponding to $Fe^{2+}$ state. This result suggests that the occurrence of ferromagnetism in reduced sample may be interpreted as the contribution of unquenched orbital moment of $Fe^{2+}$ ions.

• Journal of Oriental Neuropsychiatry
• /
• v.24 no.4
• /
• pp.393-402
• /
• 2013

Objectives: This study is a clinical report of a patient with ADHD and learning disorders who is being treated with hyperbaric oxygen, scalp acupuncture, cognitive enhancement therapy and speech-language therapy. Methods: The BASA-R, BASA-M and REVT tests were used for the diagnosis of learning disorders. For the treatment, hyperbaric oxygen therapy, scalp acupuncture, cognitive enhancement therapy and speech-language therapy were all being used. The Raven's matrix tests were compared for between before and after the abovementioned therapies. Results: After the treatment, Raven's matrix test grade improved from 4 to 5. The improvement of the patient's concentration, communication, motion, confidence, and sleep conditions were observed. Conclusions: These therapies including the hyperbaric oxygen therapy are efficient for the treatment of ADHD and learning disorders.

• 월간산업보건
• /
• s.42
• /
• pp.25-28
• /
• 1991

산업현장에서는 대단히 많은 화학물질이 원료, 기타 용도로 이용되고 있으며, 근로자는 항상 폭로 내지는 중독의 위험을 받고 있다. 따라서 그 관리를 함에 있어서는 산업에서 쓰이는 화학물질의 종류와 양, 사용공정, 근로자의 폭로 상황에서부터 폐기에 이르기까지 모든것을 파악함과 동시에 그 작업환경관리, 작업관리 및 건강관리에 관해서 법규나 실제를 상세하게 알아둘 필요가 있다. 1. 관리는 기본적으로 법규에 의거하여 실시되는데, 여기에는 최소한의 규칙이 있으며, 실제 관리에 있어서는 임기응변의 최대한 노력이 필요하다. 2. 환경관리를 하는데는 기본적으로 허용농도가 이용되며, 국제적으로는 생물학적 한계치가 제창되어 응용되고 있다. 3. 법규 또는 독성에 의거하여 특정 화학물질, 기타 각종 호칭이 쓰이고 있으며 이러한 단어는 어떤내용을 지니고 있기 때문에 충분하게 정립해 둘 필요가 있다. 4. 화학물질에 의한 중독예는 해마다 감소되고 있는데 반하여 때로 대참사를 일으키는 수도 많아서 예전부터 화학물질에 의한 급성중독에서부터 만성장기폭로로 인한 영향에 대해 관심을 모으고 있다. 특히 직업성암에 대한 문제가 대두되고 있다. 5. 사고성 대량방출이나 산소 결핍증에는 구조자나 제3자에 대한 이차성 피해가 발생되기 쉬우므로 이 점에 주의를 요한다. 6. 일반환경으로의 방출로 인해 주민에게 미치는 영향도 주의해야 한다. 7. 근로자는 화학물질의 위험성에 대하여 잘 알지 못하거나 습관적인 취급으로 인해 주의가 산만해지기 때문에 충분한 보건교육이 있어야 한다. 8. 화학물질에 의한 건강장해예방의 기본은 발생억제, 격리, 제거(배기), 체내 침입방지, 장해예방(건강진단, 생활 등)이다.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2018.05a
• /
• pp.53-57
• /
• 2018

고도의 산업화에 따라 도시의 성장과 인구의 밀집으로 인하여 물의 수요가 증가하고 이에 따라 각종 오염원의 유입이 증가함에 따라서 적절한 수질 관리에 대한 필요성이 대두되고 있다. 그리고 산업이 다양화됨에 따라 배출되는 하 폐수의 특성도 다양해져 기존의 수질처리장은 효율적인 처리를 하는데 있어 많은 어려움이 발생되고 있다. 굴 패각은 하수처리의 담체로 이용할 경우 살수여상의 문제점 중 하나로 나타나는 막힘 현상을 다소 감소시킬 수 있고, 다공질체로서 표면적이 불규칙하고 비표면적이 크기 때문에 반응기내에 공기를 원활하게 공급할 수 있으며, 중금속 이온과 유기물에 대한 흡착 효율이 뛰어나 미생물이 쉽게 부착, 성장할 수 있는 장점을 가지고 있다. 천연광물질은 전 세계적으로 발견되어 활용된 역사가 짧지만, 그 특징은 산소결핍보충, 유해원소 흡착 성능, 반도체 작용, 인체 면역력 강화, 바이러스성 질병의 예방, 중금속 해독 등의 다양한 특징으로 환경호르몬 제고, 음이온 원적외선 발생으로 세포의 노화방지, 인체 노폐물 제거와 같은 특징을 지닌 매우 유용한 자원으로 확인되고 있으며, 수질정화 능력이 탁월한 것으로 보고 있다. 이에 본 연구는 어촌폐기물인 굴 패각과 수질정화에 탁월한 천연 광물질을 혼합하여 경제적이고, 효율성이 높은 다공성 수질개선 담체를 개발하고, 수목여과용 비점오염시설 장치에 적용하여 혼합 담체가 수처리 시설의 담체로서 사용이 가능한지, 수목여과용 비점오염시설 장치에 적용할 수 있는지 검토하고자 수행하였다. 이 연구는 2017년 중소기업청 기술개발사업에서 연구지원을 받아 연구되었습니다.

• Journal of Aquaculture
• /
• v.1 no.1
• /
• pp.67-73
• /
• 1988

A growth experiment of tilapia (offsprings of the hybrid between Oreochromis niloticus and O. mossambicus) under different dissolved oxygen levels in the recirculating water system was conducted at the Fish Culture Experiment Station of the National Fisheries University of Pusan from February 4 to March 5, 1986. Six tanks with a capacity of $1.8m^3$ of water each were used under the same condition of water parameters except for dissolved oxygen levels which were designated to maintain at 1.5, 2.0, 2.5, 3.0, 3.5 and 4.0 mg/$\iota$. Each tank was stocked with 90 kg of fish each averaging 64 to 69 grams. The average water temperature during the course of the experiment was $22.5^{\circ}C$. The results obtained are summarized as follows: The food conversion efficiencies were very good, being 1.05-1.11 at 3.5, 3.0, 2.5 and 2.0 mg/$\iota$ DO levels without any significant differences among them, but at 4.0 mg/$\iota$ the F. C. was 1.39 and at 1.5 mg/$\iota$ it was 1.61 being very poor compared with the others. The daily growth rate performance was best at 3.5 mg/$\iota$ dissolved oxygen level followed by 3.0 and 2.5 mg/$\iota$ with slight differences while at 4.0 and 2.0 mg/$\iota$ DO levels the growths were significantly poor, and at 1.5 mg/$\iota$ DO level it was extremely poor. In 1.5 mg/$\iota$ group, the fish did not accept feed vigorously and after feeding the fish usually concentrated around the inflow point showing oxygen deficiency response. While at 4.0 mg/$\iota$ high feeding rates tended to waste significant amounts of feed while eating and led to water deterioration, and above these levels the results is considered to lead to a waste of energy with uneconomical performance. On the other hand, at and below 2.0 mg/$\iota$ DO level the tilapia certainly showed a poor growth performance. The experiment indicates that the DO range of 2.5$\~$3.5 mg/$\iota$ is the optimum level for the good growth performance.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
• /
• v.14 no.1
• /
• pp.12-25
• /
• 2003

Objectives：As increasing number of new antidepressants have been being introduced in clinical practice, pharmacological understanding has been broadened. These changes mandate new information and theories to be incorporated into the treatment process of children with depressive disorders. In light of newly coming knowledge, this review intended to recapitulate the characteristics of new antidepressants and to consider the pivotal issues to develope guidelines for the treatment of depression in childhood and adolescence. Methods：Searching the Pub-Med online database for the articles with the key words of 'new', 'antidepressants' and 'children' ninety-seven headings of review articles were obtained. The author selected the articles of pertinent subjects in terms of either treatment guideline or psychopharmacology of new antidepressants. When required, articles about the clinical effectiveness of individual antidepressants were separatedly searched. In addition, the safety information of new antidepressants was acquired by browsing the official sites of the United States Food and Drugs Administration and Department of Health and Human Services. Results：1) For the clinical course, treatment phase, and treatment outcome, the reviews or treatment guidelines adopted the information from adult treatment guidelines. 2) Systematic and critical reviews unambiguously concluded that selective serotonin reuptake inhibitors(SSRIs) excelled tricyclic antidepressants( TCAs) for both efficacy and side effect profiles, and were recommend for the first-line choice for the treatment of children with depressive disorders. 3) New antidepressants generally lacked treatment experiences and randomized controlled clinical trials. 4) SSRIs and other new antidepressants, when used together, might result in pharmacokinetic and/or pharmacodynamic drug-to-drug interaction. 5) The difference of the clinical effectiveness of antidepressants between children and adults should be addressed from developmental aspects, which required further evidence. Conclusion：Treatment guidelines for the pharmacological treatment of childhood and adolescence depression could be constructed on the basis of clinical trial findings and practical experiences. Treatment guidelines are to best serve as the frame of reference for a clinician to make reasonable decisions for a particular therapeutic situation. In order to fulfill this role, guidelines should be updated as soon as new research data become available.