• 한국수정란이식학회지
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• 제30권3호
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• pp.201-206
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• 2015

본 연구는 방사선 조사 후, 난소 적출을 한 흰쥐에 있어서 골회복과정 중에 셀레늄(Se)에 의한 보호 작용을 평가한 연구이다. 목적 수행을 위해 난소 적출술을 실시한 암컷 Sprague-Dawley계 흰쥐 80마리를 무작위로 ovariectomized(Ov), Ov/Se, Ov/irradiated(Irr) 그리고 Ov/Se/Irr와 같이 4개의 처리군으로 구분하였다. 골 결손은 난소적출(ovariectomy) 후, 40일에 모든 공시동물의 경골(tibia)에서 만들어졌다. 수술 후, 48시간에 Ov/Se군과 Ov/Se/Irr 처리구의 흰쥐에만 0.8 mg Se/kg을 투여하였다. 수술 후, 72시간에 Ov/Irr 군과 Ov/Se/Irr 처리구의 흰쥐에만 10Gy의 X-rays 조사를 사지부위(limb region)에 실시하였다. 수술 후, 모든 공시동물은 7, 15, 22 그리고 29일에 안락사를 시키고, 섬유주골형(trabecular bone)의 개수 분석(Masson Trichrome) 과 복 굴절 분석(Picrosirius)에 의해서 골 회복과정을 평가하였다. 난소적출한 군 및 방사선 조사한 군에서 골 재생 과정이 지연되는 현상을 확인이 가능하였다. 결론적으로, 셀렌산염 (sodium selenite)은 독성 없이 난소 적출을 한 흰쥐의 경골(tibia)의 골 재생과정에서 방사선 보호작용을 할 가능성을 제시하였다.

• Current Photovoltaic Research
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• 제3권3호
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• pp.85-90
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• 2015

Two-step processes for preparing $Cu(In,Ga)Se_2$ absorber layers consist of precursor layer formation and subsequent annealing in a Se-containing atmosphere. Among the various deposition methods for precursor layer, the nonvacuum (wet) processes have been spotlighted as alternatives to vacuum-based methods due to their potential to realize low-cost, scalable PV devices. However, due to its porous nature, the precursor layer deposited on Mo substrate by nonvacuum methods often suffers from thick $MoSe_2$ formation during selenization under a high Se vapor pressure. On the contrary, selenization under a low Se pressure to avoid $MoSe_2$ formation typically leads to low crystal quality of absorber films. Although TiN has been reported as a diffusion barrier against Se, the additional sputtering to deposit TiN layer may induce the complexity of fabrication process and nullify the advantages of nonvacuum deposition of absorber film. In this work, Mo oxide layers via thermal oxidation of Mo substrate have been explored as an alternative diffusion barrier. The morphology and phase evolution was examined as a function of oxidation temperature. The resulting Mo/Mo oxides double layers were employed as a back contact electrode for $CuInSe_2$ solar cells and were found to effectively suppress the formation of $MoSe_2$ layer.

• 시스템엔지니어링학술지
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• 제6권1호
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• pp.15-23
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• 2010

This paper describes the application method of systems engineering for systems of systems and addressed the evolution in approach as organizations have evolved from standalone platform providers to architect of SoS. There is an increasing need to perform Systems of Systems Engineering(SoSE) in a global environment This has stimulated the development of new, innovative SoSE approaches that surpass current military and industry state-of-the-art systems engineering processes. The simple scaling of the former process was ineffective in dealing with global distributed large-scale integration efforts of network-centric systems of systems. A new SoSE process has been developed which is a significant breakthrough in the development of large complex systems and net-centric systems of systems. The SoSE process provides a complete, detailed and systematic development approach for military and civil SoS. In this point of view, this paper analyzes functionally the architecture framework, process and integrated verification & validation of SoSE. From results of this analysis, perspectives on the application of SoSE suitable for Korea aquisition environment are presented.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2009년도 춘계학술대회 논문집
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• pp.83-84
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• 2009

Thin film solar cells based on CIGS continue to be a leading candidate for thin film photovoltaic devices due to their appropriate bandgap, long-term stability, and low-cost production. To date, the most successful technique for the deposition of a CIGS absorber layer has been based on the co-evaporation However, the evaporation process is difficult to scale-up for large-area manufacturing the sputtering and Selenizaton process has been a promising method for low-cost and large-scale production of high quality CIGS In this study, we have used Cu and CuIn alloy targets for precursor deposition the precursor deposited by sputtering Cu and CuIn targets and $CuInSe_2$ thin film is manufactured by Selenization process

• 한국잠사곤충학회지
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• 제18권2호
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• pp.107-110
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• 1976

In silk reeling process the carry-over cocoons must be submerged in the reeling baths filled with reeling water and left until reopening the operation. Under the detention the carry-over cocoons are apt to decay without any antiseptic treatment. Thus an useful antiseptic for the cocoons is urgently needed, and various antseptic agents have been tested for their applicability to the process. However, such an useful agent has not been developed yet. Formalin has been the only chemical used for antisepticizing carry-over cocoons, although it has many defects as the antiseptic for the cocoons. In these circumstances, recently we newly prepared an antiseptic useful for preventing the carryover cocoons from decaying. We named the new antiseptic preparation "Swi-Se-Yo." The Korean term "Swi-Se-Yo" literally means "please take a rest". Through a series of experiments with Swi-Se-Yo we obtained the following results: 1) Swi-Se-Yo, in 0.05% aqueous solution, exerted a good antiseptic effect on the boiled Cocoons submerged in the reeling baths and the effect lasted for 45 hours. The duration of the effect is about two times longer than that of Formalin. 2) The percentage of cocoon reel ability of the carry-over cocoons treated with Swi-Se-Yo was 6% higher than that of Formalin and was equal to that of flowing cold water. 3) The percentage of raw silk yield of the carry-over cocoons treated with Swi-Se-Yo was almost equal to that of Formalin and to that of flowing cold water. 4) The quality of raw silk of the carry-over cocoons treated with Swi-Se-Yo is the same as that of flowing cold water. Besides the above favourable results, Swi-Se-Yo has many advantages as an antiseptic. Chemically it is very stable. Its antimicrobial action is very strong and the spectrum is very broad. It can be available in water-soluble powder and in small bulk. And it is not harmful to human and domestic animals. Considering these profitable properties of Swi-Se-Yo, it will have a good reputation as a carry-over cocoon antiseptic. (The chemical composition and manufacturing method of Swi-Se-Yo will be published in the near future.)

• 상하수도학회지
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• 제34권6호
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• pp.411-423
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• 2020

To remove phosphorus from the effluent of public wastewater treatment facilities, hundreds of enhanced phosphorus treatment processes have been introduced nationwide. However, these processes have a few problems including excessive maintenance cost and sludge production caused by inappropriate coagulant injection. Therefore, the optimal decision of coagulant dosage and automatic control of coagulant injection are essential. To overcome the drawbacks of conventional phosphorus removal processes, the integrated sedimentation and dissolved air flotation(SeDAF) process has been developed and a demonstration plant(capacity: 100 ㎥/d) has also been installed. In this study, various jar-tests(sedimentation and / or sedimentation·flotation) and multiple regression analyses have been performed. Particularly, we have highlighted the decision-making algorithms of optimal coagulant dosage to improve the applicability of the SeDAF process. As a result, the sedimentation jar-test could be a simple and reliable method for the decision of appropriate coagulant dosage in field condition of the SeDAF process. And, we have found that the SeDAF process can save 30 - 40% of coagulant dosage compared with conventional sedimentation processes to achieve total phosphorus (T-P) concentration below 0.2 mg/L of treated water, and it can also reduce same portion of sludge production.

• 한국분말재료학회지
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• 제31권1호
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• pp.50-56
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• 2024

We report the effect of plastic deformation on the thermoelectric properties of n-type Bi₂Te_2.5Se_0.5 compounds. N-type Bi₂Te_2.5Se_0.5 powders are synthesized by an oxide-reduction process and consolidated via spark-plasma sintering. To explore the effect of plastic deformation on the thermoelectric properties, the sintered bodies are subjected to uniaxial pressure to induce a controlled amount of compressive strains (-0.2, -0.3, and -0.4). The shaping temperature is set using a thermochemical analyzer, and the plastic deformation effect is assessed without altering the material composition through differential scanning calorimetry. This strategy is crucial because the conventional hot-forging process can often lead to alterations in material composition due to the high volatility of chalcogen elements. With increasing compressive strain, the (00l) planes become aligned in the direction perpendicular to the pressure axis. Furthermore, an increase in the carrier concentration is observed upon compressive plastic deformation, i.e., the donor-like effect of the plastic deformation in n-type Bi₂Te_2.5Se_0.5 compounds. Owing to the increased electrical conductivity through the preferred orientation and the donor-like effect, an improved ZT is achieved in n-type Bi₂Te_2.5Se_0.5 through the compressive-forming process.

• 시스템엔지니어링학술지
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• 제16권1호
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• pp.78-83
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• 2020

Recently, the use of domestic products securing domestic technology is encouraged, because of export restrictions of the countries or DMSMS(diminishing manufacturing sources and shortages). Domestic weapon systems are actively focused on the parts localization process of R&D projects based on Systems Engineering. However, it is the only way to do technical review for Systems Engineering process up to now. There is a case of application in Localization with Systems Engineering process, but the SE activity is not enough. This study is how to apply Systems Engineering process to Localization effectively based on real cases.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제41회 하계 정기 학술대회 초록집
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• pp.376-376
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• 2011

I-III-VI2 chalcopyrite compounds, particularly copper, indium, gallium selenide(Cu(InxGa1-x)Se2, CIGS), are effective light-absorbing materials in thin-film solar application. They are direct band-gap semiconductors with correspondingly high optical absorption coefficients. Also they are stable under long-term excitation. CIS (CIGS) solar cell reached conversion efficiencies as high as 19.5%. Several methods to prepare CIS (CIGS) absorber films have been reported, such as co-evaporation, sputtering, selenization, and electrodeposition. Until now, co-evaporation is the most successful technique for the preparation of CIS (CIGS) in terms of solar efficiency, but it seems difficult to scale up. CIS solar cells have been hindered by high costs associated with a fabrication process. Therefore, inorganic colloidal ink suitable for a scalable coating process could be a key step in the development of low-cost solar cells. Here, we will present the preparation of CIS photo absorption layer by a solution process using novel metal precursors. Chalcopyrite copper indium diselenide (CuInSe2) nanocrystals ranging from 5 to 20nm in diameter were synthesized by arrested precipitation in solution. For the fabrication of CIS photo absorption layer, the CuInSe2 colloidal ink was prepared by dispersing in organic solvent and used to drop-casting on molybdenum substrate. We have characterized the nanoparticless and CIS layer by XRD, SEM, TEM, and ICP.

• 시스템엔지니어링워크숍
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• 통권1호
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• pp.119-126
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• 2003

After attending the special lecture by Halligan on "The Principles of Systems Engineering" at the 2002 KCOSE workshop, the author tried to collect similar SE principles scanning throughout several SE text books and internet sources. During this process it is found that INCOSE once established a SE-Principles WG and tried to collect SE-principles. They tried to make distinctions among pragmatic, mathematical, and philosophical principles. The result of this effort to collect various SE-principles showed that, including the INCOSE SE-principles WG, most authors seem only succeeded in generating the pragmatic SE-principles but failed in both mathematical and philosophical SE-principles.