• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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• pp.145-147
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• 2009

The cost effective structures and materials for the carbon nanotube (CNT) back light unit (BLU) are proposed. Simplified device structures and related electron emitter materials are prepared. CNT emitters were screen printed or remotely mounted on the back plate, and this enabled less than two photo patterning steps. Besides the cost benefits, operating voltage was dramatically decreased and higher current density was obtained

• Carbon letters
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• 제12권1호
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• pp.44-47
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• 2011

Activated carbon fibers (ACFs) were prepared from cost effective commercial textiles through stabilization, carbonization, and subsequently activation by carbon dioxide. ACFs were characterized for surface area and pore size distribution by physical adsorption of nitrogen at 77 K. ACFs were also examined for various surface characteristics by scanning electron microscopy, Fourier transform infrared spectroscopy, and CHNO elemental analyzer. The prepared ACFs exhibited good surface textural properties with well developed micro porous structure. With improvement in physical strength, the commercial textile grade acrylic precursor based ACFs developed in this study may have great utility as cost effective adsorbents in environmental remediation applications.

• 한국세라믹학회지
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• 제55권3호
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• pp.185-202
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• 2018

Photoelectrochemical (PEC) cells can convert solar energy, the largest potential source of renewable energy, into hydrogen fuel which can be stored, transported, and used on demand. In terms of cost competitiveness compared with fossil fuels, however, both photocatalytic efficiency and cost-effectiveness must be achieved simultaneously. Improvement of cost-effective, scalable, versatile, and eco-friendly fabrication methods has emerged as an urgent mission for PEC cells, and solution-based fabrication methods could be capable of meeting these demands. Herein, we review recent challenges for various nanostructured oxide photoelectrodes fabricated by solution-based processes. Hematite, tungsten oxide, bismuth vanadate, titanium oxide, and copper oxides are the main oxides focused on, and various strategies have been attempted with respect to these photocatalyst materials. The effects of nanostructuring, heterojunctions, and co-catalyst loading on the surface are discussed. Our review introduces notable solution-based processes for water splitting photoelectrodes and gives an outlook on eco-friendly and cost-effective approaches to solar fuel generation and innovative artificial photosynthesis technologies.

• 한국건축시공학회지
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• 제12권6호
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• pp.624-635
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• 2012

Construction projects, including housing, are carried out over long periods of time. According to changes to the construction period, the cost of input materials and wages also changes. Therefore appropriate management is important in order to minimize cost risks caused by fluctuations in prices. In Korea, housing units are usually sold in lots prior to construction completion. Therefore, careful management of input elements such as materials and equipment that are sensitive to price fluctuations is very important. This study deals with how the price fluctuation of materials, labor, and equipment influences the change of housing cost and seeks a way for cost management through identifying key resources sensitive to price fluctuation. As a result, a change to the housing cost index multiplies depending on cost changes of materials and labor together. Labor costs are a major factor on the housing cost index. In addition, certain types of materials and labor input to housing construction greatly influence price fluctuations. Thus, it is found that managing those main cost factors is the key for effective cost management.

• 접착 및 계면
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• 제25권1호
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• pp.143-151
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• 2024

유기태양전지(Organic photovoltaics, OPV)는 기계적 유연성, 경량, 반투명성, 낮은 제조 비용 등 여러 가지 고유한 특성을 지니고 있어 차세대 신재생 에너지원으로 큰 잠재력을 보여 왔다. 최근 분자구조 및 소자 엔지니어링의 발전으로 19% 이상의 높은 효율을 달성했다. 그러나 이러한 높은 효율을 갖춘 광활성층 물질들은 복잡한 구조로 인해 합성 과정이 복잡하며 제조비용이 높아 상용화에 어려움이 있다. 이 문제를 해결 하기 위해 간단한 구조를 갖는 저비용 광활성층 물질들에 대한 연구가 활발히 이루어지고 있다. 본 논문에서는 이러한 낮은 비용의 광활성층 물질 및 이를 합성하기 위한 전략들에 대해 소개한다.

• Journal of Electrochemical Science and Technology
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• 제12권4호
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• pp.398-405
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• 2021

To fabricate a full-scale pilot model of the cost-effective Na-(Ni,Fe)Cl₂ cell, a Na-beta-alumina solid electrolyte (BASE) was developed by applying a one-step synthesis cum sintering process as an alternative to the conventional solid-state reaction process. Also, Fe metal powder, which is cheaper than Ni, was mixed with Ni metal powder, and was used for cathode material to reduce the cost of raw material. As a result, we then developed a prototype Na-(Ni,Fe)Cl₂ cell. Consequently, the Ni content in the Na-(Ni,Fe)Cl₂ cell is decreased to approximately (20 to 50) wt.%. The #1 prototype cell (dimensions: 34 mm × 34 mm × 235 mm) showed a cell capacity of 15.9 Ah, and 160.3 mAh g^-1 (per the Ni-Fe composite), while the #2 prototype cell (dimensions: 50 mm × 50 mm × 335 mm) showed a cell capacity of 49.4 Ah, and 153.2 mAh g^-1 at the 2^nd cycle.

• Membrane and Water Treatment
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• 제10권4호
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• pp.259-264
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• 2019

Cost effective clay adsorptive microfiltration membranes were synthesized to remove Cr (III) from high polluted water. Raw and calcined bentonite were mixed in order to decrease the shrinkage and also increase the porosity; then, 20 wt% of carbonate was added and the samples, named B (without carbonate) and B-Ca20 (with 20 wt% calcium carbonate) were uniaxially pressed and after sufficient drying, fired at $1100^{\circ}C$ for 3 hours. Then, physical and mechanical properties of the samples, their phase analyses and microstructure and also their ability for Cr(III) removal from high polluted water (including 1000 ppm Cr (III) ions) were studied. Results showed that the addition of calcium carbonate lead the porosity to increase to 33.5% while contrary to organic pore formers like starch, due to the formation of wollastonite, the mechanical strength not only didn't collapse but also improved to 36.77 MPa. Besides, sample B-Ca20, due to the presence of wollastonite and anorthite, could remove 99.97% of Cr (III) ions. Hence, a very economic and cost effective combination of membrane filtration and adsorption technology was achieved for water treatment which made microfiltration membranes act even better than nanofiltration ones without using any adsorptive nano particles.

• 한국조리학회지
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• 제6권1호
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• pp.151-175
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• 2000

In hotels or Food service industrials they make efforts on cost control. In the modern time how to control costs of food materials are perceived to be important even if there are many ways of cost control. Ideas that the cost of food material should be accounted have been change to that the cost of food material should be controlled. change of thought and the spread-over of computer give us the means of effective cost control over the processes of buying, controling, selling food materials. Even if stocked in good places, the food materials are changing in quality from the first time they are stocked. the storage control give us the least loss of this damages and make us to provide customers progressive food services in quality rather than the past. we can make plans to save costs corresponding to take various way of buying suitable to various situation.

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.209-209
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• 2006

Ultra-fine fibers are spun by expensive fiber spinning technology using special spinnerets. Ultra-fine fibrous materials have attracted considerable attentions because of their potential applications as high performance wiping cloths, water absorbent sound proofing materials and moisture transfer sporting good. However, production expense of ultra-fine fibers is 5 to 7 times higher than general textile materials. The objective of this research is to develop cost-effective recycling process to produce multi-functional ultra-fine fibrous material in terms of the development of garnetting and carding machines for ultra-fine fibrous material waste and scrap. The efficiency of sound absorption for the recycled polyester nonwoven increased with decreasing length and thickness of component fibers, which was attributed to the reduction of air permeability. It is expected that high value and cost-effective textile products are developed using ultra-fine fibrous wastes and that sound proofing material and oil absorbent f

• 한국재료학회지
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• 제27권9호
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• pp.466-470
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• 2017

With the matters of climate change, energy security and resource depletion, a growing pressure exists to search for replacements for fossil fuels. Among various sustainable energy sources, hydrogen is thought of as a clean energy, and thus efficient hydrogen storage is a major issue. In order to realize efficient and safe hydrogen storage, various porous materials are being explored as solid-states materials for hydrogen storage. For those purposes, it is a prerequisite to characterize a material's textural properties to evaluate its hydrogen storage performance. In general, the textural properties of porous materials are analyzed by the Brunauer-Emmett-Teller (BET) measurement using nitrogen gas as a probe molecule. However, nitrogen BET analysis is sometimes not suitable for materials possessing small pores and surfaces with high curvatures like MOFs because the nitrogen molecule may sometimes be too large to reach the entire porous framework, resulting in an erroneous value. Hence, a smaller probe molecule for BET measurements (such as hydrogen) may be required. In this study, we describe a cost-effective novel cryostat for BET measurement that can reach temperatures below the liquefaction of hydrogen gas. Temperature and cold volume of the cryostat are corrected, and all measurements are validated using a commercial device. In this way, direct observation of the hydrogen adsorption properties is possible, which can translate directly into the determination of textural properties.