• Journal of the Korean Society for information Management
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• v.19 no.3
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• pp.237-261
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• 2002

The purpose of this study is to measure the library online service quality based on the expectation and the service performance from the users' point of view. The online questionnaire was developed based on SERVQUAL, however information quality dimension was added on it, and the survey was conducted within a research library. The factor analysis for effecting library online services showed that 5 service dimensions were loaded discretely, and information quality was put in the other dimension. The IPA (Important Performance Analysis) result confirmed that information quality, service reliability, and service assurance were considered as important factors : multiple regression analysis revealed that tangibility and information quality were the most significant dimension for the library online service.

• Journal of Korean Library and Information Science Society
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• v.36 no.2
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• pp.93-120
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• 2005

The purpose of this study was to delve into literature of library service quality, including recent studies on the same theme, and to suggest what types of major issues there were and what should be studied in the future. Specifically, the concept and characteristics of service quality, service quality models, service determinants (outcome variable), user satisfaction and e-service were discussed. Articles on the quality of information service, like library-related LibQual, were examined, and it's attempted to make a comprehensive review of studies on service quality and to introduce major international studies on same issues. Finally, what future research efforts should focus on in each field was presented.

• Proceedings of the Korean Institute of Resources Recycling Conference
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• 2005.10a
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• pp.173-177
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• 2005

리튬이온 2차전지(Lithium ion battery, LIB)는 기존에 사용되던 전지에 비해 에너지 밀도가 높고 충방전 사이클이 우수하다. 이 때문에 휴대전화와 노트북 등에 수요가 급속하게 증가하고 있으며 1995년 LIB의 생산량은 4천만 개에서 2004년에는 약 8억 개로 20배 이상 증가하였다. 이에 따라 폐LIB도 급속하게 증가하게 되어 전국적인 재활용 시스템의 확보가 필요한 실정이다. 본 연구에서는 폐LIB에 함유되어 있는 유가금속 중에서 리튬코발트옥사이드(이하 $LiCoO_2$)를 회수하기 위하여 분쇄기(orient vertical cutting mill)와 진동 Screen을 사용하여 유기분리막, 금속류(Aluminium foil, Copper foil, case 등) 그리고 전극물질(lithium cobalt oxide와 graphite 등의 혼합 분말)로 분리하였다. 전극물질에서 $LiCoO_2$와 graphite 분리를 위한 전처리 단계로서 $500^{\circ}C$ 정도의 열처리를 하여 $LiCoO_2$의 표면 성질을 변화시켜 부유선별에 의해 $LiCoO_2$와 graphite의 분리가 가능하도록 하였다. 부유선별 실험 결과 93% 이상의 순도를 가지는 $LiCoO_2$를 92% 이상 회수할 수 있었다.

• Journal of the Korean Chemical Society
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• v.3 no.1
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• pp.23-27
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• 1954

The relation between the height of ascending solvents and its velocity were studied with strips of Toyo No. 50 filter paper. The filter paper strip of 3cm width and cat 30 cm length is hooked down or fixed between two sheets of glass plates inside a cylinder containing the solvent, in which the lower end of the strip is dipped. As the solvents, acetone, hydrochloric acid, water or mixtures of these are used. For short time intervals, Ostwald's folmula $h = Kt^n$ was found to be most suitable to express the relation between the height of the solvent front, h, and time, t. For longer time intervals, results will be discussed in the next paper. The mean values of the constant m in the above formula for pure acetone and pure water were 0.44 and 0.485, respectively, and that of K were 0.05 and 2.4, respectively. The time interval whose the above formula applies, for each solvent was 2 hours for the former, and a half hour for the later, respectively. The movement of solutes, such as $Cu^{++}$ and $Fe^{++}$ showed that the Rf values of solutes become constant values after a long periods; e.g., ca. 6 hours with 10N-HCl-Acetone (1 : 9) solvent.

• Journal of the Korean Chemical Society
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• v.4 no.1
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• pp.7-9
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• 1957

On sparking carbon-arc in water we found that a inflammable gas was generated. The object of this experiment is to prepare sols of metals by applying the gas mentioned to a solution of metallic salts. As the result of this experiment we found that : 1) By this method we can prepare easily some kinds of Ag-sol from $AgNO_3$ solution in about 30 sec. by adjusting the temperature, the quantity of stabilizer and the concentration of metallic salt. 2) The appropriate concentration of $AgNO_3$ is about 0.01% by volume, that of the stabilizer, 0.9104 N-NaOH is 0.03-2 cc/100 cc of 0.01% $AgNO_3$ solution. And the lower the temperature, the more concentrated the Ag-sol. But to check the possibility of applying this method to metals other than Au and Ag, measurement of the particle size and properties of a sol prepared by this method, should be studied. Especially, we must study what kinds of gases are generated by sparking the carbon-arc in water.

• Journal of the Korean Society for Library and Information Science
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• v.39 no.1
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• pp.127-145
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• 2005

Today we are preparing to accept the ubiquitous library age. This article will serve to define the concepts of the hybrid library, the gateway library and the ubiquitous library which hold the advanced concepts of the digital library. It will review the main projects about them in order to portray what the future libraries will be like and how they can be developed. In particular, the eLib program of the hybrid library, the gateway projects by Harvard University and Penn State University, and the ubiquitous library projects in Carnegie Melon University and Maryland University will be surveyed, through which the characteristics of the information services being operated by the ubiquitous libraries will be scanned.

• Journal of Electrochemical Science and Technology
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• v.9 no.3
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• pp.184-194
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• 2018

In this paper, we propose a rapid-charging system for the lithium-ion battery (LIB) packs used in electric forklifts. The battery offers three benefits: reduced charge time, prolonged battery life, and increased charging efficiency. A rapid-charging algorithm and DC/DC converter topology are proposed to achieve these benefits. This algorithm is developed using an electrochemical model, which controls the maximum charging current limit depending on the cell voltage and temperature. The experimental use of a selected 18650 LIB cell verified the prolongation of battery life on use of the algorithm. The proposed converter offers the same topological merits as a conventional resonant converter but solves the light-load regulation problem of conventional resonant converters by adopting pulse-width modulation. A 6.6-kW converter and charging algorithm were used with a forklift battery pack to verify this method's operational principles and advantages.

• Asian-Australasian Journal of Animal Sciences
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• v.3 no.3
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• pp.219-223
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• 1990

Sixtyfour Baluchi lambs about 5 months of age were divided into four groups with 16 lambs each. All the animals were grazed together. Group No.1 (G-1) was kept as control i.e. on grazing only; while group No. 2 (G-2) was offered barley grain @ 200 g/head/day as supplement to grazing; Group No. 3 (G-3) was offered ad-lib urea-molasses block (UMB) with 6% cement and group No.4 (G-4) was fed ad-lib IMB having 8% cement. These UMB were fed as supplement to grazing. Experiment lasted for 105 days (July to October) in arid zone of Baluchistan. Daily per head consumption of block No.1 was found to be 92.71 g; while that of block No.2 was observed to be 90.77 g. Growth rate (g/head/day) was found to be 10, 50, 33 and 15 in G-1, G-2, G-3 and G-4 respectively. Expenditure/kg bodyweight gain was found to be rupees 12.00, 3.64 and 7.74 for G-2, G-3 and G-4 respectively.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.34 no.5
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• pp.327-332
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• 2021

Lithium-ion batteries (LIBs) have become a main energy storage device in various applications, such as portable appliances, renewable energy facilities, and electric vehicles. However, the poor thermal stability of LIBs may cause explosion or fire. The thermal runaway is the result of a failure of the separator inside LIB. Damages like tearing, piercing, and collapsing of the separator were simulated in a mechanical, an electrical, and a thermal way, and small discharge pulses of a few mV were detected at the time of separator damages. From the experimental results, this paper provided a method that can identify the separator failure before thermal runaway in the aspect of a potential explosion and fire prevention measures.

• Journal of the Korean Society of Safety
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• v.37 no.2
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• pp.76-87
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• 2022

Lithium-ion batteries (LIBs) have attracted much interest for their high energy density (>150 mAh/g), high capacity, low self-discharge rate, and high coulombic efficiency. However, with the successful commercialization of LIBs, fire and explosion incidents are likely to increase. The thermal runaway is known as the major factor in battery-related accidents that can lead to a series of critical conditions. Considering this, recent studies have shown an increased interest in countering the safety issues associated with LIBs. Although safety standards for LIB use have recently been formulated, little attention has been paid to the safety around the manufacturing process for battery products. The present study introduces a risk assessment method suitable for assessing the safety of the LIB-manufacturing process. In the assessment method, a compensation parameter (Z-factor) is employed to correctly evaluate the process's safety on the basis of the type of material (e.g., metal anode, liquid electrolyte, solid-state electrolytes) utilized in a cell. The proposed method has been applied to an 18650 cell-manufacturing process, and three sub-processes have been identified as possibly vulnerable parts (risk index: >4). This study offers some crucial insights into the establishment of safety standards for battery-manufacturing processes.