• Clean Technology
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• v.14 no.3
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• pp.176-183
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• 2008

The purpose of this study is to upgrade the catalysts for synthesizing mixed octenes using normal butene and the catalysts for synthesizing $C_9$-aldehyde through hydroformylation of mixed octenes with syngas. The in-line activation method with circulating activating solution was effective for activation of the $NiO/A1_{2}O_3$ catalyst. The reason for catalyst deactivation may be ascribed to physi-sorbed materials or oligomers which block pore entrance and then prevent active sites from participating a reaction. Continuous distillation apparatus was used for separating mixed octenes from dimerization products. When reflux ratio was above 3 : 1, mixed octene fraction of which purity was above 99.57% was obtained. In $C_9$-aldehyde synthesis through hydroformylation of mixed octenes, we investigated a performance of ligand which increased catalyst stability as well as activity of Co catalyst. The results indicated that TPPO, NMP, NDMA, and succinonitrile were suitable ligand for increasing initial activity and reducing loss of Co during catalyst recovery.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.34 no.1
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• pp.43-50
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• 2008

Ceramides, a constituent of stratum corneum lipids, play a crucial role in the formation and maintenance of the epidermal permeability barrier. As in many other skin disorders, atopic dermatitis and psoriasis show decrease and transformation of the ceramides. The application of ceramide has been demonstrated to be efficient in the repair of these skin disorders. Nevertheless, natural ceramides are still too expensive and small in quantity to be used as a cosmetic ingredient. Although a lot of pseudo-ceramides have been developed and on the market until now, those pseudo-ceramides did not fully meet the consumer's needs, therefore, there is still a demand for a novel pseudo-ceramides. We synthesized a novel pseudo-ceramide BPC-16 from 2-(2-amino-ethylamino)-ethanol(AEEA), which was characterized by structures having both amide bonds and hydroxyl groups as hydrophilic units, as well as two long alkyl chains. We formulated emulsion with BPC-16, cholesterol, stearic acid, and other components to make an emulsion. These emulsion showed a typical optical anisotropy on cross-polarized microscopy. This 'Maltese cross' appearance is a characteristic figure observed in concentric lamellar emulsion under cross-polarized microscopy. In cytotoxicity assay using MTT in monolayer and three dimension(3D) cell culture, a BPC-16 showed only negligible cytotoxicity up to the effective concentration for barrier repair and moisturization(less than 10 mM). In the measurement of TEWL, this BPC-16 showed significant recovery of water-retaining properties when it was topically applied to either SDS-induced dry skin or normal skin compared to that of base cream. This novel pseudo-ceramide BPC-16 showed as effective in skin barrier repair and moisturization as natural ceramides.

• Analytical Science and Technology
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• v.25 no.2
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• pp.91-101
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• 2012

A list of volatile fatty acids (VFA) including propionic acid, butyric acid, isovaleric acid, valeric acid, etc. is well known for offensive odorants. The analysis of odorant VFA is a highly delicate task due to high reactivity and unstable recovery rate. At present, analytical methods of VFA are recommended to include alkali impregnation filter method and alkali absorption method by the malodor prevention law of the Korea Ministry of Environment (KMOE). In this review, a survey has been made to explore various approaches available for the analysis of VFA to include both official methods of the KMOE and others. In light of the unreliability of those established analytical methods, it is highly desirable to develop some substituting methods for VFA. Among such options, one may consider such option as sorbent tube (ST) sampling and cryogenic trapping-thermal desorption technique. Moreover, procedures used for standard preparation, sampling steps, and instrumental detection stage are also evaluated. Application of container sampling (like Tedlar bag) is however not recommendable due to significant (sorptive) loss in sampling and in storage stage. In the detection stage, the use of GC/MS is recommendable to replace GC/FID due to the presence of diverse interfering substances. Thus, it is essential to properly establish the basic quality assurance (QA) for VFA analysis in air.

• Korean Journal of Remote Sensing
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• v.31 no.6
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• pp.513-521
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• 2015

In the processing of ocean color remote sensing data, spatio-temporal binning is crucial for securing effective observation area. The validity determination for given source data refers to the information in Level-2 flag. For minimizing the stray light contamination, NASA OBPG's standard algorithm suggests the use of large filtering window but it results in the loss of effective observation area. This study is aimed for quality improvement of ocean color remote sensing data by recovering/extending the portion of effective observation area. We analyzed the difference between MODIS/Aqua standard and modified product in terms of chlorophyll-a concentration, spatial and temporal coverage. The recovery fractions in Level-2 swath product, Level-3 daily composite product, 8-day composite product, and monthly composite product were $13.2({\pm}5.2)%$, $30.8({\pm}16.3)%$, $15.8({\pm}9.2)%$, and $6.0({\pm}5.6)%$, respectively. The mean difference between chlorophyll-a concentrations of two products was only 0.012%, which is smaller than the nominal precision of the geophysical parameter estimation. Increase in areal coverage also results in the increase in temporal density of multi-temporal dataset, and this processing gain was most effective in 8-day composite data. The proposed method can contribute for the quality enhancement of ocean color remote sensing data by improving not only the data productivity but also statistical stability from increased number of samples.

• Nuclear Engineering and Technology
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• v.27 no.4
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• pp.470-482
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• 1995

The Ulchin 3&4, which are 2825 MWt PWRs, adopted Safety Depressurization System (SDS) to mitigate the beyond design basis event of Total Less of Feedwater(TLOFW). In this study the results and methodology of the analyses for the determination of SDS bleed capacity are discussed. The SDS design bleed capacity has been determined from the CEFLASH-4AS/REM simulation according to the following design criteria : 1) Each SDS flow path, in conjunction with one of two High Pressure Safety Injection (HPSI) pumps, is designed to have a sufficient capacity to prevent core uncovery if one SDS path is opened simultaneously with the opening of the Pressurizer Safety Valves (PSVs). 2) Both SDS bleed paths are designed to have sufficient total capacity with both HPSI pumps operating to prevent core uncovery if the Feed and Bleed (F&B) initiation is delayed up to thirty minutes from the time of the PSVs lift. To verify the results of CEFLASH-4AS/REM simulation a comparative analysis kas also been per-formed by more sophisticated computer code, RELAP5/MOD3. The TLOFW event without operator recovery and TLOFW event with F&B are analyzed. The predictions by the CEFLASH-4AS/REM of the transient too phase system behavior are in good qualitative and quantitative agreement with those by the RELAP5/MOD3 simulation. Both of the results of analyses by CEFLASH-4AS/REM and RELAP5/MOD3 have demonstrated that decay heat removal and core inventory make-up can be successfully accomplished by F&B operation during now event for the Ulchin 3&4.

• Archives of Plastic Surgery
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• v.38 no.5
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• pp.616-620
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• 2011

Purpose: Mayer-Rokitansky-Kuster syndrome (MRK) is second common cause of primary amenorrhea. It is a syndrome of vaginal aplasia and Mullerian duct anomaly. Vaginal aplasia varies from agenesis of whole vagina to aplasia of upper 2/3. For reconstructing vagina, various methods are introduced. Gracilis myocutaneous flap was the first attempt in that the flap is used in vaginal reconstruction. Various flap-based vaginal reconstruction methods have been introduced. Modified Singapore flap (pedicled neurovascular pudendal thigh fasciocutaneous flap) is one of those methods that used posterior labial artery as pedicle, and pudendal nerve branch as sensory root. As its donor lies on inguinal crease that is easily hidden and there are benefits on sexual intercourse by early sensory recovery, authors think that modified Singapore flap is effective for young MRK syndrome patients. Methods: Eight patients underwent surgery between 2008 and 2010. The flap was designed on both groin area with external pudendal artery branch as a pedicle. All flaps were fixated in pelvic cavity with absorbable suture, and additional compression on neovaginal wall was supplied by polyvinyl alcohol sponge ($Merocel^{(R)}$). Results: All patients were successfully reconstructed without flap related complications such as congestion or partial flap loss. The average size of the flap (each side) was 69.34 $cm^2$. Polyvinyl alcohol sponge ($Merocel^{(R)}$) was inserted into neovagina for 5 days on every patient. One case of rectal laceration was occurred while making pelvic pocket by OBGY team. Other complications such as lumen narrowing, wound contracture or vaginal prolapsed were not reported during 8 months of follow up. Conclusion: Modified Singapore flap is a sensate fasciocutaneous flap that is thinner than other myocutaneous flap such as VRAM, and more durable over skin graft. Therefore this is a good choice for vaginal reconstruction in MRK syndrome. And known complications of Modified Singapore flap could be reduced with careful procedure and mild compression techniques.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.6 no.2
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• pp.187-201
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• 1996

This study was to evaluate the efficiency of diffusive monitor using activated carbon fiber(ACF, KF-1500) in measuring airborne organic solvents. The following characteristics were identified and studied as critical to the performance of diffusive monitor; recovery, sampling rate, face velocity, reverse diffusion and storage stability. For the evaluation of the performance of this monitor, MIBK, PCE, toluene were used as organic solvents. In the sampling rate experiments, eight kinds of solvents (n-hexane, MEK, DIBK, MCF, TCE, CB, xylene, cumene) as well as the above solvents were used. The results were as follows: 1. The desorption efficiencies(DE's) of ACF diffusive monitor ranged from 83 % to 101 %. In contrast, those of coconut shell charcoal ranged from 78 % to 102 %. Especially, the DE's of ACF for the polar solvents such as MEK were superior to those of charcoal. 2. Experimental sampling rates on ACF were average 42ml/min(37-46ml/min) for 11 organic solvents at $24{\pm}2^{\circ}C$, $50{\pm}5%RH$. However ideal sampling rates(DA/L) were 33 % higher than experimental sampling rates. 3. The initial response(15~16 min) of the testing monitor was 2 times higher than the actual concentration determined by the reference methods at $24{\pm}2^{\circ}C$, $8{\pm}5%RH$ and $80{\pm}5%RH$. Within 1 hours, the curve reached a linear horizontal line at low humidity condition. But sampling efficiencies decreased with respect to time at high humidity condition. And sampling efficiencies were higher at high humidity condition than low humidity condition for MIBK. 4. At very low velocity (less than 0.02 m/sec), the concentration of ACF diffusive monitor were poorly estimated. But ACF diffusive monitor were not affected at higher velocity(0.2 m/sec-0.6 m/sec). 5. There was no significant reverse diffusion when the ACF monitors were exposed to clean air for 2 hours after being exposed for 2 hours at the level of 1 TLV. 6. There was no significant sample loss during 3 weeks of storage at room temperature and 5 weeks of storage at refrigeration.

• Journal of the Mineralogical Society of Korea
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• v.32 no.3
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• pp.185-200
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• 2019

This study aimed to liberate gold from invisible gold concentrate (Au = 1,840.00 g/t) through microwave nitric acid leaching experiments. For the purpose, this study conducted microwave-nitric acid leaching experiments and examined nitric acid concentration effect, microwave leaching time effect and sample addition effect. The results of the experiments were as follows: Au (gold) contents were not detected in all of the microwave leaching conditions. In the insoluble-residue, weight loss rate tended to decrease as the nitric acid concentration, microwave leaching time and sample addition increased. In an XRD analysis with solid-residue, it was suggested that gypsum and anglesite were formed due to dissolution of calcite and galena by nitric acid solution. When a fire assay was carried out with insoluble-residue, it was discovered that gold contents of the solid-residue were 1.3 (Au = 2,464.70 g/t) and 28.8 (52,952.80 g/t) times more than those of concentrate. But in the gold contents recovered, a severe gold nugget effect appeared. It is expected that the gold nugget effect will decrease if a sampling method of concentrate is improved in the microwave-nitric acid leaching experiments and filtering paper with smaller pore size is used for leaching solution and burned filter paper is used for sampling in lead-fire assay.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1976.06a
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• pp.85.3-86
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• 1976

Sudden deafness requires immediate investigation and treat if there is to be any prospect of salvaging the hearing. It present an otological emergency and a diagnostic challenge. Sn Sudden sensorineural deafness can be caused by a wide variety of pathologies. A battery of tests and investigations must be performed forthwith if treatment is to be started without further delay. The concept that nothing can be done for the patient with sensori-neural deafness must be abandoned. Some pathologies causing sudden deafness are not amenable to therapy or can show only partial reversibility. But there are several causes, showing little or no spontaneous recovery, which do responed to appropriate treatment. It is important to identify them and concentrate on their management. The age and sex ratios and the unilaterral or bilateral nature of the lesion are related to the etiology and depend upon which type of case is included in the series. Though individually rare, collecting for about 2.5 per cent of new otoloical patients. Some 70 per cent of cases are unilateral. Viral, bacterial and treponemal infections accounted for about 30 per cent of the cases. Some 16 per cent were due to vascular lesions of the cochlea. In almost 22 per cent there was no obvious cause (idiopathic), they occurred in young adult and were either sensory or neural. About 12 per cent were traumatic and 9 per cent were ototoxic in origin. The remaining 11 per cent were due to a group of rarities. The two vital factors are the site of the lesion and the duration of the hearing loss. The earlier these are diagnosed and treated the better the response. The etiology, pathology and treatment are reviewed.

• Journal of Platform Technology
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• v.9 no.1
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• pp.15-22
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• 2021

In a smart manufacturing environment, more and more devices are connected to the Internet so that a large volume of data can be obtained during all phases of the product life cycle. The large-scale industries, companies and organizations that have more operational units scattered among the various geographical locations face a huge resource consumption because of their unorganized structure of sharing resources among themselves that directly affects the supply chain of the corresponding concerns. Cloud-based smart manufacturing paradigm facilitates a new variety of applications and services to analyze a large volume of data and enable large-scale manufacturing collaboration. The manufacturing units include machinery that may be situated in different geological areas and process instances that are executed from different machinery data should be constantly managed by the super admin to coordinate the manufacturing process in the large-scale industries these environments make the manufacturing process a tedious work to maintain the efficiency of the production unit. The data from all these instances should be monitored to maintain the integrity of the manufacturing service system, all these data are computed in the cloud environment which leads to the latency in the performance of the smart manufacturing service system. Instead, validating data from the external device, we propose to validate the data at the front-end of each device. The validation process can be automated by script validation and then the processed data will be sent to the cloud processing and storing unit. Along with the end-device data validation we will implement the APM(Asset Performance Management) to enhance the productive functionality of the manufacturers. The manufacturing service system will be chunked into modules based on the functionalities of the machines and process instances corresponding to the time schedules of the respective machines. On breaking the whole system into chunks of modules and further divisions as required we can reduce the data loss or data mismatch due to the processing of data from the instances that may be down for maintenance or malfunction ties of the machinery. This will help the admin to trace the individual domains of the smart manufacturing service system that needs attention for error recovery among the various process instances from different machines that operate on the various conditions. This helps in reducing the latency, which in turn increases the efficiency of the whole system