• 설비공학논문집
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• 제29권6호
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• pp.327-340
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• 2017

This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2016. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) The research works on the thermal and fluid engineering have been reviewed as groups of flow, heat and mass transfer, the reduction of pollutant exhaust gas, cooling and heating, the renewable energy system and the flow around buildings. CFD schemes were used more for all research areas. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics, pool boiling and condensing heat transfer and industrial heat exchangers. Researches on heat transfer characteristics included the results of the long-term performance variation of the plate-type enthalpy exchange element made of paper, design optimization of an extruded-type cooling structure for reducing the weight of LED street lights, and hot plate welding of thermoplastic elastomer packing. In the area of pool boiling and condensing, the heat transfer characteristics of a finned-tube heat exchanger in a PCM (phase change material) thermal energy storage system, influence of flow boiling heat transfer on fouling phenomenon in nanofluids, and PCM at the simultaneous charging and discharging condition were studied. In the area of industrial heat exchangers, one-dimensional flow network model and porous-media model, and R245fa in a plate-shell heat exchanger were studied. (3) Various studies were published in the categories of refrigeration cycle, alternative refrigeration/energy system, system control. In the refrigeration cycle category, subjects include mobile cold storage heat exchanger, compressor reliability, indirect refrigeration system with $CO_2$ as secondary fluid, heat pump for fuel-cell vehicle, heat recovery from hybrid drier and heat exchangers with two-port and flat tubes. In the alternative refrigeration/energy system category, subjects include membrane module for dehumidification refrigeration, desiccant-assisted low-temperature drying, regenerative evaporative cooler and ejector-assisted multi-stage evaporation. In the system control category, subjects include multi-refrigeration system control, emergency cooling of data center and variable-speed compressor control. (4) In building mechanical system research fields, fifteenth studies were reported for achieving effective design of the mechanical systems, and also for maximizing the energy efficiency of buildings. The topics of the studies included energy performance, HVAC system, ventilation, renewable energies, etc. Proposed designs, performance tests using numerical methods and experiments provide useful information and key data which could be help for improving the energy efficiency of the buildings. (5) The field of architectural environment was mostly focused on indoor environment and building energy. The main researches of indoor environment were related to the analyses of indoor thermal environments controlled by portable cooler, the effects of outdoor wind pressure in airflow at high-rise buildings, window air tightness related to the filling piece shapes, stack effect in core type's office building and the development of a movable drawer-type light shelf with adjustable depth of the reflector. The subjects of building energy were worked on the energy consumption analysis in office building, the prediction of exit air temperature of horizontal geothermal heat exchanger, LS-SVM based modeling of hot water supply load for district heating system, the energy saving effect of ERV system using night purge control method and the effect of strengthened insulation level to the building heating and cooling load.

• 환경생물
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• 제22권2호
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• pp.247-258
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• 2004

Climatological, hydrological and planktonical research studies, measurements of primary production and photosynthetic efficiency from December 1976 to December 1978 have been carried out in two brackish lakes: Lake Etang de Berre and Lake Etang de Vaine located in the French Mediterranean coast, in the region of Carry-le-Rouet located on the north-west Mediterranean near Marseilles, and in fresh water inflows from 4 Rivers (Touloubre, Durance, Arc, Durancole) to Lake Etang de Berre. Physico-chemical parameters were measured for this study: water temperature, salinity, density, pH, alcalinity, dissolved oxygen (% saturation), phosphate, nitrate, nitrite, silicate etc. Diverse biological parameters were also studied: photosynthetic pigments, phaeopigments, specific composition and biomass of phytoplankton, primary pelagic production etc. Climatical factors were studied: air-temperature, solar-radiation, evaporation, direction (including strength) of winds, precipitation and freshwater volume of the four rivers. The changes in Lake ‘Etang de Berre’ ecosystem depend on the quality of the water in the Durance River, and on the effects of seawater near the entrance of the Caronte Canal. The water quality of the lake varies horizontally and vertically as a result of atmospheric phenomena, maritime currents and tides. The distribution of water temperatures is generally heterogeneous. Southeasterly winds and the Northeasterly Mistral wind are important in the origins of circulated and mixed water masses. These winds are both frequent and strong. They have, as a result, a great effect on the water environment of Lake Etang de Berre. In theory, the annual precipitation in this region is well over eight times the water mass of the lake. The water of the Durance River flows into Lake Etang de Berre through the EDF Canal, amounting to 90% of the precipitation. However, reduction of rainfall in dry seasons has a serious effect on the hydrological characteristics of the lake. The temperature in the winter is partially caused by the low temperature of fresh water, particularly that of the Durance River. The hydrological season of fresh and brackish water is about one month ahead of the hydrological season of sea water in its vicinity. The salinity of Lake Etang de Berre runs approximately 3$\textperthousand$, except at lower levels and near the entrance to the Caronte Canal. However, when the volume of the Durance River water is reduced in the summer and fall, the salinity rises to 15$\textperthousand$. In the lake, the ratio of fresh water to sea water is six to one (6:1). The large quantities of seston conveyed by rivers, particularly the Durance diversion, strongly reduce the transparency in the brackish waters. Although the amount of sunshine is also notable, transparency is slight because of the large amount of seston, carried chiefly by Tripton in the fresh water of the Durance River. Therefore, photosynthesis generally occurs only in the surface layer. The transparency progressively increases from freshwater to open seawater, as mineral particles sink to the bottom (about 1.7kg $m^{-2}a^{-1}$ on the average in brackish lakes). The concentration of dissolved oxygen and the rate of oxygen saturation in seawater (Carry-le-Rouet) ranged from 5.0 to 6.0 $m\ell$ㆍ.$1^{-1}$, and from 95 to 105%, respectively. The amount of dissolved oxygen in Etang de Berre oscillated between 2.9 and 268.3%. The monographs of phosphate, nitrate, nitrite and silicate were published as a part of a study on the ecology of phytoplankton in these environments. Horizontal and vertical distributions of these nutriments were studied in detail. The recent diversion of the Durance River into Lake Etang de Berre has effected a fundamental change in this formerly marine environment, which has had a great impact in its plankton populations. A total of 182 taxa were identified, including 111 Bacillariophyceae, 44 Chlorophyceae, and 15 Cyanophyceae. The most abundant species are small freshwater algae, mainly Chlorophyceae. The average density is about $10^{8}$ cells $1^{-1}$ in Lake Etang de Berre, and about double that amount in Lake Etang de Vaine. Differences in phytoplankton abundance and composition at the various stations or at various depths are slight. Cell biovolume V (equivalent to true biomass), plasma volume VP (‘useful’ biomass) and, simultaneously. the cell surface area S and S/V ratio through the measurement of cell dimensions were computed as the parameters of phytoplankton productivity and metabolism. Pigment concentrations are generally very high on account of phytoplankton blooms by Cyanophyceae, Chlorophyceae and Cryptophyceae. On the other hand, in freshwaters and marine waters, pigment concentrations are comparatively low and stable, showing slight annual variation. The variations of ATP concentration were closely related to those of chlorophyll a and phytoplankton blooms only in marine waters. The carbon uptake rates ranged between 38 and 1091 mg$Cm^{-2}d^{-1}$, with an average surface value of 256 mg; water-column carbon-uptake rates ranged between 240 and 2310 mg$Cm^{-2}d^{-1}$, with an average of 810, representing 290 mg$Cm^{-2}$, per year 45 000 tons per year of photosynthetized carbon for the whole lake. Gross photosynthetic production measured by the method of Ryther was studied over a 2-year period. The values obtained from marine water(Carry-le-Rouet) ranged from 23 to 2 337 mg$Cm^{-2}d^{-1}$, with a weighted average of 319, representing about 110 gCm$^{-2}$ per year. The values in brakish water (Etang de Berre) ranged from 14 to 1778 mg$Cm^{-2}d^{-1}$, with a weighted average of 682, representing 250 mg$Cm^{-2}$ per year and 38 400 tons per year of photosynthesized carbon for the whole lake.

• 한국식품영양과학회지
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• 제17권2호
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• pp.125-135
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• 1988

예부터 우리나라 특유의 조미료로 상용되어온 재래식 간장을 제조함에 있어 강한 발암성 물질인 N-nitrosamine(NA)의 생성유래를 밝히고, 나아가서 이들의 생성을 억제시키는 방안의 일환으로써 몇몇 종의 식품첨가제를 이용하여 NA 생성에 미치는 영향을 검토하였고, 동시에 NA 생성과 밀접한 관계가 있는 유리아미노산, dimethylamine(DMA), 질산염 및 아질산염의 변화를 검색하였다. 간장숙성중 DMA 질소는 다소간 불규칙한 변화를 보이고 있으나 대체로 숙성과 더불어 증가하는 경향이었다. DMA의 억제효과는 ascorbic acid 및 sodium benzoate 처리구가 DMA생성을 숙성초기에 크게 억제시켰으나 숙성말기에는 큰영향을 미치지 못하였다. 질산염질소는 간장이 숙성되는 과정중 계속해서 감소하는 추세였으나, 반면 아질산염질소는 증가하였다. 아질산염의 생성을 최소화하기 위해서는 ascorbic acid가 가장 효과적인 식품첨가제였다. N-nitrosodimethylamine (NDMA)은 간장숙성중 증가하는 경향을 보여 대조구의 경우 숙성 30일에 $2.7{\mu}g/kg$, 숙성 90일에 $10.7{\mu}g/kg$검출되었다. 그러나 N-nitrosodiethylamine(NDEA) 및 N-nitrosodipropylamine(NDPA) 은 전혀 검출되지 않았다. 식품첨가제가 NDMA의 생성에 대한 억제효과는 시판식염으로 제조한 간장에서는 대조구에 비해 ascorbic acid 처리구가 $82.2{\sim}87.0%$, sorbic acid 처리구 $25.9{\sim}65.4%$ 및 sodium benzoate 처리구에서는 $13.2{\sim}63.5%$의 억제효과를 보였다. 그리고 순 NaCI로 제조한 간장중 NDMA의 함량은 ascorbic acid 처리구가 1.5㎍/㎏이하로서 대조구에 비해 NDMA의 생성이 크게 억제되었다. 간장중에 존재하는 유리아미노산이 NDMA의 생성을 억제시킨다는 것이 본 실험에서 밝혀졌고, 이중 특히 glutamic acid, proline 및 histidine이 주된 아미노산으로 추정되며 모델실험결과 간장중 유리아미노산을 제거할 경우 NDMA의 생성을 30.3%나 촉진시켰다.

• 분석과학
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• 제24권2호
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• pp.69-77
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• 2011

에틸렌 글리콜은 주로 자동차, 선박, 항공기 등의 부동액 성분으로 우리 실생활에 널리 쓰 이고 있으며 그 만큼 접근성이 용이하여 자살 목적이나 보관 사용 단계에서 의도적 혹은 실수로 인한 오용 사고가 끊이지 않고 있다. 에틸렌 글리콜 자체는 인체에 대한 독성이 그리 크지 않으나 생체 내에서 대사 과정을 거치면서 보다 독성이 높은 대사체를 생성하게 되며, 특히 글리콜산과 옥살산 대사체는 에틸렌 글리콜 중독의 주된 독성 발현체로서 대사성 산증 및 조직 손상 등을 유발하고 최종적으로 치사에 이르게 한다, 에틸렌 글리콜 중독으로 판정할 수 있는 가장 결정적인 데이터는 생체 시료 중 에틸렌 글리콜 농도가 되겠으나, 에틸렌 글리콜은 반감기가 3 ~ 5시간 정도로 매우 짧아 발견 당시 이미 상당 수준의 단계로 대사가 진행되어 있는 경우가 많고, 병원 등에서 위 세척 등 응급 치료 중 사망하기도 하며, 경우에 따라서는 매우 늦게 발견되어 시체가 부패되어 혈액을 채취할 수 없는 등, 에틸렌 글리콜 분석만으로 사인을 규명하기 어려운 때가 있으며, 이런 경우에 대사체의 분석이 필수적이다. 본 연구에서는 에틸렌 글리콜로 인하여 사망한 4건의 사례에서 혈액 및 조직 등 11점의 생체 시료에서 에틸렌 글리콜과 초기 대사체인 글리콜산 및 최종 대사체인 옥살산의 함량을 분석하고 그 분포에 대하여 살펴보았다. 에틸렌 글리콜 분석은 유도체화 후 가스크로마토그래프/질량분석법으로, 글리콜산과 옥살산 분석은 이온크로마토그래피로 수행하였으며, 혈액에서(3건)에서 에틸렌 글리콜 농도는 $10\sim2,400\;{\mu}g/mL$ 글리콜산 농도는 $224\sim1,164\;{\mu}g/mL$ 옥살산 농도는 불검출 $\sim40\;{\mu}g/mL$ 이었다. 간, 신장, 담즙, 흉강 액의 시료(3건)에서는 에틸렌 글리콜 농도는 불검출 $\sim55,000\;{\mu}g/mL$ 글리콜산 농도는 불검출 $\sim1,124\;{\mu}g/mL$ 옥살산 농도는 불검출 $\sim60\;{\mu}g/mL$ 이었다. 간 조직과 신장 조직에서는 치료 등에 따라 에틸렌 글리콜이 검출되지 않더라도 최종 대사체인 옥살산이 의미 있는 양으로 검출되어, 혈액과 더불어 유용한 생체 증거물 시료로서 권장되었다.

• 한국농공학회지
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• 제17권4호
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• pp.3943-3955
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• 1975

The purposes of this study are to evaluate the utilization characteristics of electrical power consumption, to grasp the present trends in the use of electrical equipments, to estimate the demand factor and load factor being held, and to evaluate the efficiency of electical uses for the recently electrified farms cultivating paddy rice. For the purposes, 109 sample farms located in eleven villiages electrified in six different years from 1968 to 1973, were chosen at random and investigated on 35 items concerning to electrical uses and wiring systems. The survey was carried out in 1975, in the vinicity of Suweon city. The results are summarized as follows: i) The average annual power consumption on sample farms is considered to be low, being 242.9 Kwh. in 1974, and varied according to the different electrified year and size of cultivated land, respectively. It has significant positive correlation to the area of farm, too. ii) Between the number of year of electrical uses and the power consumption, there is very significant positive correlation, which could be expressed as Y=43.041+16.108 X, where X represents the number of years of electrical uses. The annual increment of power consumption is much greater at the beginning of the electrification than that at the later years, its average being approximately 20 percent. However, it is recommended that any estimation of long-term increments should be carefully investigated. iii) The monthly power consumption varies considerably throughout a year, in which the heaviest farm load occurs in November. Observing the seasonal variation of consumption, the winter-time is the heaviest season while the summer is the lowest. The result implies house lighting is chief contribution to the present electrical consumption on the farms. Comparing the variation of monthly consumption ratios between the sample farms and industries, the electrical uses on the farms are independant of the industrial uses, and further, the agricultural uses are of inverse pattern to the farms from the results that there is negative correlationship between them, iv) The number of electrical equipments used on the farms are occupied chiefly by lighting sources. Next to the lighting sources, household appliances of small quantity and some motors are used. The mean electrical quantity is about 1, 127.4 watt, which corresponds to about 37.6 per cent to the contracted quantity. The composition of quantity is chiefly occupied by the electrical motor of about 1.5 hp., single-phased. The number of the annual utilization hours of each equipment is tabulated in Table IV-5. In contradiction to the high utilization of lighting sources and small household appliances, the motor is poorly used for approximately 22 hours in a year. v) More than 55 per cent of farms want to purchase new electrical equipments such as small household appliances and electrical motors in their number. The impulse of purchasing such items is stimulated by the contacts to the mass media and their knowledge on such equipments. Consequently, the increase of electrical uses could be prompted by such trials as education and demonstration. vi) The demand and load factors on the farms vary considerably according to the greater variation of the power consumption, daily or monthly. The daily demand factor is 22.4 per cent and load factor 18.6 per cent, while the annual demand factor is 1.3 per cent and load factor 70 per cent approximately. Therefore, the low efficiency of construction cost requires re-evaluation of the present contracted quantity of 3 Kw. or increase of electrical uses. vii) The electrical energy on the farms devoted chiefly to lighten the farm residences does not contribute to the farm incomes. Consequently, the cost of electrical consumption presses considerably upon the farm economy. Therefore, there is great need to build up the electrical uses on the farms through the development of new works and techinques to utilize any electrical equipments on the production of farm products. Further more, such the development should be related to increase the actual income of the farm consumers.

• 한국수산과학회지
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• 제26권4호
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• pp.380-391
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• 1993

고밀도의 어류양식 순환수 처리씨스템 개발을 위하여 양식장의 수질특성 조사 및 생물학적 유동층 공정에 의한 모형 폐수처리 장치로 운영 실험한 결과를 요약하면 다음과 같다. 1) 단일어종을 양식하는 H 및 S 양만장 폐수의 경우 BOD $9.4{\sim}13.1\;mg/l$, COD(Mn) $14.5{\sim}20.0\;mg/l,\;NH_4-N\;1.1{\sim}2.3\;mg/l,\;NO_3-N\;15{\sim}21\;mg/l$이었고, 틸라피아 등 3종의 어류를 사육하는 B 및 K 양식장에서는 BOD $9.3{\sim}11.3\;mg/l$, COD(Mn) $8.0{\sim}11.1\;mg/l,\;NH_4-N\;7.3{\sim}20.2\;mg/l,\;NO_3-N\;26.9{\sim}46.4\;mg/l$의 수질특성을 나타내었다. 2) H 및 S 양만장 폐수의 BOD/COD 비율은 0.65로 거의 동질의 유기물 농도 값을 가지며, 틸라피아 등 3 종의 어류를 사육한 B 및 K 양식장 폐수에서는 크게 상이하였다. 3) 양식장의 여과조 및 동육조내 DO 농도를 기준으로 한 시간별 수질변동폭은 $1.5{\sim}2.0$ 배로 조사되었다. 4) 양만장 폐수의 탄소성 유기물 분해속도상수값은 $0.049\;d^{-1}$, 질산화반응 속도상수값은 $0.035\;d^{-1}$로서 미생물 분해작용에 의한 BOD 곡선식은 다음과 같이 나타낼 수 있었다. $y_T=14.1(1-10^{-0.222t)+30.9(1-10^{-0.035(t-8)})$ 5) BFB 처리 씨스템의 $0.014{\sim}0.075g\;NH_4-N/g\;BVS{\cdot}day$ 부하 조건 하에서 5 배의 암모니아성 질소 부하량 증가에도 질산화율은 $65{\sim}79\%$로 안정되게 나타났다. 6) BFB 처리 씨스템에 있어서 $0.014g\;NH_4-N/g\;BVS{\cdot}day$의 낮은 암모니아성 질소 부하조건에서는 공존 유기물 농도가 실산화 반응속도 저하 요인으로 작용하였다. 7) 부하율 변화 영향을 받지 않을 것으로 예측되었던 미생물 농도 $3.04{\sim}3.44\;g/l$의 무산소 BFB 탈질 씨스템에서 T-N 부하율 증가시 T-N 제거율 감소경향이 뚜렷하였던 바, 그 이유는 화기성조내에서 호기성 질산화 미생물의 증식이 억제되었기 때문으로 파악되었다. 8) 부하율 변화에 따른 처리율의 안정성과 반응조내에서 고농도의 미생물유지 잠재력을 확보하는 BFB 방법은 소요 부지면적이 작고 처리효율을 임의로 선택할 수 있는 실용성이 보장되므로 기존의 처리방법보다 설계 및 운영면에서 유리할 것으로 평가되었다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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• pp.107-108
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• 2008

The spectacular development of AMLCDs, been made possible by a-Si:H technology, still faces two major drawbacks due to the intrinsic structure of a-Si:H, namely a low mobility and most important a shift of the transfer characteristics of the TFTs when submitted to bias stress. This has lead to strong research in the crystallization of a-Si:H films by laser and furnace annealing to produce polycrystalline silicon TFTs. While these devices show improved mobility and stability, they suffer from uniformity over large areas and increased cost. In the last decade we have focused on microcrystalline silicon (${\mu}c$-Si:H) for bottom gate TFTs, which can hopefully meet all the requirements for mass production of large area AMOLED displays [1,2]. In this presentation we will focus on the transfer of a deposition process based on the use of $SiF_4$-Ar-$H_2$ mixtures from a small area research laboratory reactor into an industrial gen 1 AKT reactor. We will first discuss on the optimization of the process conditions leading to fully crystallized films without any amorphous incubation layer, suitable for bottom gate TFTS, as well as on the use of plasma diagnostics to increase the deposition rate up to 0.5 nm/s [3]. The use of silicon nanocrystals appears as an elegant way to circumvent the opposite requirements of a high deposition rate and a fully crystallized interface [4]. The optimized process conditions are transferred to large area substrates in an industrial environment, on which some process adjustment was required to reproduce the material properties achieved in the laboratory scale reactor. For optimized process conditions, the homogeneity of the optical and electronic properties of the ${\mu}c$-Si:H films deposited on $300{\times}400\;mm$ substrates was checked by a set of complementary techniques. Spectroscopic ellipsometry, Raman spectroscopy, dark conductivity, time resolved microwave conductivity and hydrogen evolution measurements allowed demonstrating an excellent homogeneity in the structure and transport properties of the films. On the basis of these results, optimized process conditions were applied to TFTs, for which both bottom gate and top gate structures were studied aiming to achieve characteristics suitable for driving AMOLED displays. Results on the homogeneity of the TFT characteristics over the large area substrates and stability will be presented, as well as their application as a backplane for an AMOLED display.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2010년도 하계학술대회 논문집
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• pp.375-375
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• 2010

CdTe as an absorber material is widely used in thin film solar cells with the heterostructure due to its almost ideal band gap energy of 1.45 eV, high photovoltaic conversion efficiency, low cost and stable performance. The deposition methods and preparation conditions for the fabrication of CdTe are very important for the achievement of high solar cell conversion efficiency. There are some rearranged reports about the deposition methods available for the preparation of CdTe thin films such as close spaced sublimation (CSS), physical vapor deposition (PVD), vacuum evaporation, vapor transport deposition (VTD), closed space vapor transport, electrodeposition, screen printing, spray pyrolysis, metalorganic chemical vapor deposition (MOCVD), and RF sputtering. The RF sputtering method for the preparation of CdTe thin films has important advantages in that the thin films can be prepared at low growth temperatures with large-area deposition suitable for mass-production. The authors reported that the optical and electrical properties of CdTe thin film were closely connected by the thickness-uniformity of the film in the previous study [1], which means that the better optical absorbance and the higher carrier concentration could be obtained in the better condition of thickness-uniformity for CdTe thin film. The thickness-uniformity could be controlled and improved by the some process parameters such as vacuum level and RF power in the sputtering process of CdTe thin films. However, there is a limitation to improve the thickness-uniformity only in the preparation process [1]. So it is necessary to introduce the external or additional method for improving the thickness-uniformity of CdTe thin film because the cell size of thin film solar cell will be enlarged. Therefore, the authors firstly applied the chemical mechanical polishing (CMP) process to improving the thickness-uniformity of CdTe thin films with a G&P POLI-450 CMP polisher [2]. CMP process is the most important process in semiconductor manufacturing processes in order to planarize the surface of the wafer even over 300 mm and to form the copper interconnects with damascene process. Some important CMP characteristics for CdTe were obtained including removal rate (RR), WIWNU%, RMS roughness, and peak-to-valley roughness [2]. With these important results, the CMP process for CdTe thin films was performed to improve the thickness-uniformity of the sputtering-deposited CdTe thin film which had the worst two thickness-uniformities of them. Some optical properties including optical transmittance and absorbance of the CdTe thin films were measured by using a UV-Visible spectrophotometer (Varian Techtron, Cary500scan) in the range of 400 - 800 nm. After CMP process, the thickness-uniformities became better than that of the best condition in the previous sputtering process of CdTe thin films. Consequently, the optical properties were directly affected by the thickness-uniformity of CdTe thin film. The absorbance of CdTe thin films was improved although the thickness of CdTe thin film was not changed.

• 대한골관절종양학회지
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• 제9권2호
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• pp.148-154
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• 2003

목적: 신경초종은 말초신경 혹은 중추신경에 발생하는 종양이나 대개 무통성 종괴를 주소로 내원하며 신경증상이 드물기 때문에 임상적으로 신경섬유종, 결절종 혹은 지방종 등과 감별이 어려운 경우가 자주 있다. 이에 신경초종의 자기공명영상의 특징적 소견 찾아 조직학적 소견과 비교, 분석하고 임상적 특징 및 수술적 치료의 결과를 알아보기 위해 본 연구를 시행하였다. 대상 및 방법: 1996년 1월부터 2002년 6월까지 수술적 제거술 후 병리조직학적으로 신경초종으로 확진 된 73명의 환자 중 사지에서 발생한 67명을 대상으로 임상기록, MRI 및 EMG 소견, 조직병리 소견, 수술 후 경과 및 합병증 등을 후향적으로 분석하였다. 남녀의 발생빈도 차이는 없었으며, 초진시 나이는 최소 8세에서 최고 75세로 평균 44.7세였다. 추시기간은 최단 3 개월에서 최장 46개월, 평균 9.7개월이었다. 결과: 자기공명영상 검사는 근육들 사이에 T1강조영상에서 중간 신호강도, T2강조영상에서 높은 신호강도를 나타내는 경계가 분명한 방추형의 연부 조직 음영이 특징적으로 모신경에 연결되어 보였다. T2 강조상에서는 주변부의 고강도 신호와 중심부의 저강도 신호를 나타내는 target pattern이 6례(15%)에서 나타났고, 24례(62%)에서 높은 신호강도 내부에 특징적으로 비균질의 저강도 신호 음영이 나타나 fasciculation 같이 보였다. 25례(64%)에서는 다양한 크기의 낭종성 변화를 보였다. 수술 후 합병증은 5명에서 저림증, 2명에서 감각이상, 1명에서 비복신경 손상, 1명에서 요골신경 손상이 발생하였으나 추시 관찰 중 모두 호전되었다. 수술 후 재발한 경우는 없었으며, 악성변화를 한 경우도 없었다. 결론: 수술 전 자기공명영상 검사에 의한 정확한 진단과 조심스러운 적출술로 좋은 치료결과를 얻을 수 있을 것으로 사료된다.

• 지질공학
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• 제14권4호
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• pp.461-468
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• 2004

이 연구에서는 암반 내 절리면의 거칠기 정도에 따른 수리특성의 차이를 규명하고자 Barton(1976)이 제안한 절리면 거칠기 계수(Joint Roughness Coefficient; JRC) 등급별로 투수계수를 산정하였다. 이를 위하여 JRC등급 형태별로 고속퓨리에 변환을 이용한 스펙트럼 분석을 실시하여 각 거칠기 등급별로 영향력 이 큰 주파수 성분을 추출하였다. 스펙트럼 분석결과 낮은 JRC 등급을 갖는 절리들이 높은 등급의 절리들보다 저주파 성분이 더 강하게 구성되어 있으며, 높은 JRC등급의 절리들은 상대적으로 고주파 성분이 더 크게 차지하는 것을 알 수 있었다. 스펙트럼 성분 중에서 영향력이 큰 주파수 성분만을 이용하여 퓨리에 역변환을 실시해 JRC 등급별 절리 모델을 생성하였다. 생성된 절리 모델은 거칠기 성분을 포함한 모델로써, 균질화 해석기법을 이용하여 각 모델의 투수계수를 산정하였다. 균질화 해석법은 섭동이론을 적용한 것으로서, 미시규모(microscale) 매질특성과 거시규모(macroscale) 매질특성을 동시에 고려하여 투수계수를 계산할 수 있으므로 균열 기하양상의 국부적 영향을 고려한 투수특성을 정확히 해석할 수 있다. 균질화 해석법을 이용해 투수계수를 산정한 결과, 절리 간극이 동일한 평행판 모델을 가정한 JRC 등급별 투수계수는 $10^{-3}\~10^{-4}m/sec$의 범위에 분포한다. 반면, 전단변형이 발생한 것을 가정한 모델에서는 $10^{-4}\~10^{-5}m/sec$의 범위에 투수계수가 분포한다. 이 경우는 투수계수 분포가 일정한 변화양상을 보이지 않고 JRC등급에 따라 불규칙적인 투수계수 분포를 보인다. 동일한 크기의 간극을 갖는 경우임에도 불구하고 JRC 등급별로 투수계수의 차이가 발생하거나 전단변위에 따라 투수계수가 불규칙적으로 분포하는 것은 거칠기 변화가 투수계수의 변화에 영향을 미침을 지시하는 것으로서, 이 연구를 통해 암반내 절리 등 균열을 따른 수리특성 규명에 있어 절리면 거칠기의 영향은 반드시 고려되어야 함을 알 수 있다.