• Journal of Korean Neurosurgical Society
• /
• v.52 no.5
• /
• pp.501-504
• /
• 2012

Objective : To report our surgical experience using in situ end-to-side bypass for giant serpentine distal anterior cerebral artery aneurysm, unsuitable for microsurgical clipping. Methods : A 49-year-old woman presented with headache and intermittent loss of consciousness. The brain computed tomography scan revealed a partially calcified mass in the interhemispheric fissure. On cerebral angiography, that was giant ($30{\times}18mm$ sized), serpentine aneurysm originating from the A2 to A3 segment of the distal anterior cerebral artery (DACA). The aneurysm was trapped with clips, and the right A3 segment to left A3 segment of DACA, end-to-side in situ bypass was performed. Surgical result was favorable, with no newly developed ischemic event in the acute recovery period. Postoperative angiography showed total occlusion of the aneurysm and good patency, with preserved distal flow. Conclusion : Giant fusiform aneurysms of the DACA are extremely rare and can be particularly challenging to treat. End-to-side A3 : A3 bypass with aneurysm trapping could be a treatment modality for these locations.

• Journal of Environmental Science International
• /
• v.9 no.1
• /
• pp.43-47
• /
• 2000

A study on the remediation of heavily for ion contaminated soils from abandoned iron mine was carried out, using ex-situ extraction process. Also, oxalic acid as a complex agent was evaluated as a function of concentration, reaction time and mixing ratio of washing agent in order to evaluate Fe removability of the soil contaminated from the abandoned iron mine. Oxalic acid showed a better extraction performance than 0.1N-HCl, i.e., the concentrations of Fe ion extracted from the abandoned mine for the former at uncontrolled pH and the latter were 1,750 ppm and 1,079 ppm, respectively. The optimum washing condition of oxalic acid was in the ratio of 1:5 and 1:10 between soil and acid solution during l hr reaction. The total concentrations of Fe ion by oxalic acid and EDTA at three repeated extraction, were 4,554 ppm and 864 ppm, respectively. The recovery of Fe ions from washing solution was achieved, forming hydroxide precipitation and metal sulfide under excess of calcium hydroxide and sodium sulfide. In addition, the amounted of sodium sulfide and calcium hydroxide for the optimal revovery of Fe were 15g/$\ell$ and 5g/$\ell$ from the oxalic acid complexes, respectively.

• The Journal of Engineering Geology
• /
• v.16 no.2 s.48
• /
• pp.125-134
• /
• 2006

In order to establish the in-situ application of the artificial storage and recovery (ASR) technology which is used the property of the aquifer storage of groundwater. We carried out to the in-situ experiments such as borehole TV logging, pumping test and artificial hydraulic fracturing in volcanic island, Ulleungdo. In-situ experiments were conducted to divide the before- and after-hydraulic fracturing. Pumping test was achieved to confirm the two fracture zones, GL-13m and GL-21m, which are determined by the borehole TV logging. From the results of the before- and after-pumping tests, the hydraulic connectivity was confirmed to locate at GL-13m in the residual deposit zone of pumice media as alluvium. However, in the bedrock tone at GL-21m the hydraulic connectivity could be considered to faulty. Consequently, in this study area the artificial recharge has a little unsatisfied to geo-structural condition and desired to more detail investigation works.

• Journal of the Korean Geotechnical Society
• /
• v.29 no.1
• /
• pp.71-80
• /
• 2013

Before and after the test constructions, and after an 11-month hiatus from the pilot pile installations, the in-situ tests (CPT, SPT) were carried out at the ground adjacent to the noise- and vibration-free screw concrete piles installed by 2 kinds of construction methods (i.e., the toe-jetting shoe type, the pre-digging type). In the toe-jetting shoe type construction methods, after construction, the soil strength within 3.5D (where, D = pile diameter) from the pile center decreased greatly by about 46% of the original ground and, after an 11-month hiatus, a strength recovery adjacent to the piles appeared about 71% of the original ground. In the pre-digging type construction methods, a strength recovery adjacent to the piles appeared 100% of the strength of the original ground.

• Membrane Journal
• /
• v.8 no.2
• /
• pp.69-76
• /
• 1998

Membrane technologies have been used frequently in industries, taking advantage of that it is energy-saving and employable in relatively large scale. The fact that a non-mass separating agent is used in mild conditions without phase change in membrane separation makes it a method of choice in the recovery of biological materials. Recently, the development of noble separating modules has been solving the inherent problems in membrane separation, the fouling and the concentration polarization. In addition, membrane separation has broadened its applications from the conventional crude separation to the purificational use by the advent of the new and functional membrane materials. The role of membrane technologies is expected to be enormous in the production and recovery of biological products, considering the excellent applicability of membrane in the fields of integrated separation and in-situ separation, the two trends in modem bioseparation.

• Proceedings of the National Institute of Ecology of the Republic of Korea
• /
• v.3 no.3
• /
• pp.129-138
• /
• 2022

Reintroduction programs have been promoted across the world to recover and rehabilitate endangered birds through ex situ captive breeding and releasing to the nature. The ultimate aims of these reintroduction programs are recovery of sustainable populations in natural habitats. To ensure the success of the reintroduction programs, it is necessary to examine the followings in order to increase the success rate of releasing along with the development of captive breeding techniques: 1) Adequate habitat provision, 2) adaptability of captive-bred individuals, 3) survivability of released individuals, and 4) social interest and will. Before releasing captive-bred individuals, it should be reviewed whether there are habitats in which the limiting factor is removed, and assessed their long-term safety. The quantity and quality of the released individuals must be considered to increase the chances for mate selection, maintain genetic diversity, and acquire the ability to adapt to the wild. The release method must be decided in consideration of characteristics of the target habitats and individuals, and rational means such as careful observation, evaluation, and feedback must be provided throughout the release process. For the long-term success of recovery projects, social awareness, sustainable support, and related experts are needed. Satisfying these criteria can help to increase the success rates of reintroduction programs. For the bird reintroduction program in the future, the feasibility of the methods and procedures must be closely reviewed before starting.

• 한국생물공학회:학술대회논문집
• /
• 2002.04a
• /
• pp.112-115
• /
• 2002

The green colonial algae Botryococcus braunii is characterized by unusual high hydrocarbon contents, ranging from 15 to 75% of dry weight, as long-chain unsaturated hydrocarbons. In two-phase bubble column using various organic solvents, poor recovery 08 - 32%) of hydrocarbon seems to be caused by insufficient mixing between two phases, which was operated using only aeration on the narrow interface between hydrophobic solvent and cell suspension. In addition, hydrocarbon was entrapped tightly in cell-matrix (formed by exopolysaccharide) of algal colony, which make difficult to extract using two-phase system. To improve recovery efficiency, mixed-solvent of extractive solvent (octane) and biocompatible solvent (octane) was tested in two-phase column for in situ extraction. In two-phase extraction culture using mixed-solvent, the algal growth was intensely inhibited even at low concentration of polar octanol solvent. the hydrocarbon recovery in two-stage cell-recycle extraction showed a 2.9 fold increase (57%) over that in two-phase extraction. Up to 60 % of hydrocarbon could be recovered without serious cell-damage in the case of downstream separation for 6 h at the high recycle flow rate using this process after batch culture.

• Journal of the Korean GEO-environmental Society
• /
• v.17 no.10
• /
• pp.63-71
• /
• 2016

Soil filling or replacement are routinely applied for soil restoration of domestic asbestos waste contaminated areas. However, since these soil recovery methods could not fundamentally solve the asbestos contamination, number of research on new alternative technologies have been carried. In this study, comprehensive laboratory test results utilizing wind power apparatus are used to design wind power purification device that can be applied in practice. Preliminary tests were carried out with wollastonite or actual asbestos waste contamination soils to study purification efficiency. Asbestos content measured immediately after in-situ test on asbestos-contaminated soil satisfying for purification standard showing less than 0.25% asbestos content from all tests, hence, analyzed to ensure over 90% of clean soil recovery rate and considered to be excellent applicability of future asbestos-contaminated soil purification.

• Journal of Microbiology and Biotechnology
• /
• v.1 no.3
• /
• pp.220-226
• /
• 1991

Large and rapid increases in benzophenanthridine alkaloid production occured in suspension cultures of Eschscholtzia californica cells treated with elicitors. Response to different biotic elicitors showed that elicitors prepared from yeast extract, Collectotrichum lindemuthianum and Verticillium dahliae induced alkaloid formation. Highest alkaloid accumulation was obtained with $60\;\mu\textrm{g}$ of yeast extract elicitor per gram of fresh cell weight. In time course performance after elicitor addition, more than 40 hours were required to obtain saturated alkaloid accumulation. Compounded silicone fluid, an ideal accumulation phase for two-phase culture of E. californica, accumulated a large amount of alkaloids produced in a specific manner. Elicitation in two-phase culture clearly increased net alkaloid production as well as their concentrations in the accumulation phase.

• Applied Chemistry for Engineering
• /
• v.25 no.3
• /
• pp.262-267
• /
• 2014

SAGD (steam assisted gravity drainage) process is the most commonly used in-situ technology for the recovery of bitumen from oil sand. It was investigated that the effects of different additives on bitumen recovery rate from oil sand in SAGD process among many possible mechanisms studied throughout the study. Bitumen recovery from thin layer oil sand reservoirs was simulated by using an experimental SAGD apparatus with scale of 150:1. To improve the simulation accuracy of thin layer oil reservoir, we have attached geological model (GM). Oil sand was simulated by using a mixture of extra heavy oil and glass beads with a diameter of 1.5 mm. $CO_2$ was used as an additive and the evolution of steam chambers were closely monitored, and the effects of $CO_2$ as an additive was investigated. Two types of injection methods were tested; continuous ($cCO_2$-SAGD) and sequential interruption ($sCO_2$-SAGD) $CO_2$ injection. For the $sCO_2$-SAGD experiment, it was observed that the recovery rates and CSOR were efficiently improved control experiment from 60.2% to 69.3% and 7.1 to 6.0, respectively, whereas $cCO_2$-SAGD experiment decreased from 60.2% to 57.6% and 7.1 to 7.3.