• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2001.04a
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• pp.26-26
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• 2001

사무용 고지의 상당량을 차지하는 복사고지는 열과 압력으로 융착된 합성고분자 물질인 토너를 함유하고 있으며 이들 토너는 펄핑 후 크고 판상 형태의 잉크 입자를 형성하 여 기존의 부유부상법으로 제거가 곤란한 문제점을 지니고 있었다. 이러한 문제점을 극복하 는 방안으로 응집제를 이용하는 방법을 검토하였다. 복사기용 인쇄 잉크로 널리 사용되는 토너 업자는 낮은 표면에너지를 가지는 소수 성 물질이므로 같은 표면 특성을 가지는 소수성 물질과 서로 잘 결합한다. 따라서 소수성의 응집제를 이용하면 분리된 토너 잉크업자를 응집시킬 수 있으며, 응집된 토너 응집체는 스 크린 또는 클리닝 같은 정선 공정을 이용하여 제거가 가능할 것이다. 따라서 복사고지를 효 과적으로 재활용할 수 있는 탈묵방법으로 응집제를 이용하여 토너 입자를 조대한 웅집체로 형성시키고 이를 기존 탈묵방법인 스크린처리로 제거하는 방법을 검토하였다. 본 연구에서는 고급알코올의 하나언 1 -octadecanol을 이용하여 기존의 탈묵 방법 인 부유부상법으로는 제거가 곤란한 토너 잉크의 업자를 웅집시켜 구형의 조대한 응집체로 형성시켜 이를 제거하는 기술에 대하여 연구하였다. 펄핑 시의 온도를 70C의 고온으로 설 정한 경우 토너 입자가 유리전이온도에 이르게 되며 이들 토너 입자는 응집제에 의하여 웅 집되어 구형으로 성장하는 특정이 뚜렷하였으며, 토너 응집체의 크기는 최대 800 µm에 이 르기까지 조대하게 성장하였다. 또한 슬롯 폭 $250\mu\textrm{m}$의 진동 스크린 처리에 의한 토너 제 거 효율 측정 결과 역시 이들 토너 업자 웅집체의 형태가 구형임을 보여주었다. 해리 및 응 집 처 리 시 의 pH를 3으로 조정 하였을 때 토너 입 자가 웅집 제인 1 -octadecanol에 의 해 가장 효과적으로 구형의 조대한 웅집체를 이루는 것으로 나타났으며, 스크련을 통한 토너 웅집체 제거효율이 향상되었다. 복사고지 내에 포함되어 있는 전분 또는 사이즈제는 웅집 효과를 떨어뜨리는 주요 인으로 나타났다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.2
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• pp.139-147
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• 2021

Livestock manure is used as an organic fertilizer to replace chemical fertilizers after sufficient fermentation in an aerobic bioreactor. On the other hand, liquid manure disposal problems occur repeatedly because soil spraying is restricted during the summer when the crops are growing. To use liquid fertilizer (LF) as an additional nutrient source for crops, it is necessary to reduce the amount of suspended solids (SS) in the liquid fertilizer and secure stability problems against pathogenic microorganisms. This study examined the effects of the simultaneous SS removal and E.coli sterilization in the LF using the microbubble (MB) generator (FeMgO catalyst insertion). The remaining SS were further removed using the integrated microbubble and microfilter system. During the floating process in the MB device, the SS were removed by 57.9%, and the coliform group was not detected (16,200→0 MPN/100 mL). By optimizing the HRT of the integrated system, the removal efficiency of the SS was improved by 92.9% under the 0.1h of HRT condition. After checking the properties of the treated LF, 64.5%, 70.1%, 54.9%, and 51.5% of the TCOD, SCOD, PO4-P, and TN, respectively, were removed. The treated effluent from such an integrated system has a lower SS content than that of the existing LF and does not contain coliforms; therefore, it can be used directly as an additional fertilizer.

• Composites Research
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• v.22 no.6
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• pp.52-62
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• 2009

This paper is for the state of the art of the lightweight protective clothing against the mine, and it covers the preliminary work focused on the appropriate protection, ballistics, convenience, and wearability. It is suggested that the lightweight protective clothing should be fabricated with the laminated materials of high strength woven and non-woven fabrics to reduce the weight and thickness, thus improving the wearability. And partial reinforcement of the protective clothing is necessary to prevent the mortal wound near the important parts of the body without disturbing the arbitrary activity. The composition of the protective clothing should be designed in consideration of easy putting-on and taking-off in addition to easy divesture, which require little motion of the body is in case of serious injury. Additionally, status of the practical technique for high performance and ultra-light hybrid armor material were also described.

• Journal of the Korean Geosynthetics Society
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• v.6 no.1
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• pp.9-16
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• 2007

Geotextile is one of the most useful and effective polymer material in civil construction works and the main function of geotextile is separation, reinforcement, filtering and drainage. Recently, because of the shortage of natural rock, traditional forms of river and coastal structures have become very expensive to build and maintain. Therefore, the materials used in hydraulic and coastal structures are changing from the traditional rubble and concrete systems to the cheaper materials and systems. One of these alternatives employs geotextile tube technology in the construction of coastal and shore protection structures, such as embankment, see dyke, groins, jetties, detached breakwaters and so on. Geotextile tube technology has changed from being an alternative construction technique and, in fact, has advanced to become the most effective solution of choice. This paper presents case history of sea dyke filter construction using geotextile tube mattress and also, various issues related to the tube mattress design and construction technology.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.5
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• pp.251-259
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• 2016

This study examined the DO concentration distribution and ORP distribution using microbubbles on pilot-scale aeration tanks. As a result of MLSS mixing and oxygen transfer phenomenon using microbubbles, different DO concentrations were observed depending on the circulation of the liquid with the microbubble supply location on the lateral of an aeration tank. The simulation results of CFD (computational fluid dynamics) program showed that MLSS mixed with a microbubble supply in the middle the reactor is much better than on the left side of the reactor. A single reactor containing an anaerobic, anoxic, and aerobic zone, was evaluated without partition according to the location of the microbubble supply based on the experiments and CFD analysis. MLSS was separated into solid-liquid by the microbubble supply in the aeration tank. Consequently, selecting the appropriate microbubble size is important for MLSS mixing and was maintained at the proper DO concentration for biological treatment.

• Clean Technology
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• v.10 no.4
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• pp.195-201
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• 2004

Cellulase was modified with copolymer with polyethylene(PE)/polypropylene(PP) oxide and maleic anhydride(MA) by maleylation reaction, and modified cellulase was applied to the reprocessing of old newsprint (ONP). Cellulase of modified cellulase enhanced the detachment of ink particles by fibrillation of fiber. The copolymer, which acted as the surfactant formed bubbles and removed the ink particles in the floatation process. Modified cellulase showed the same deinking ability without excess dosage compared with the conventional method. And, it improved the physical properties including tensile strength, brightness, and whiteness compared with the conventional deinking process. The bond between the ink and fiber got stronger as the storage time increased, and it became very difficult to remove the ink particle. But, modified cellulase increased the deinking ability by 41% compared with the conventional process at the experiment of the ONP for 1 year storage time. It removed the yellowing and increased the whiteness and brightness as well as tensile strength and internal bond strength.

• Journal of Korea Multimedia Society
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• v.10 no.3
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• pp.335-347
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• 2007

VoIP (Voice over IP) is a technology to transport video and voice traffic over IP networks such as Internet. Today, the VoIP technology is viewed as the right choice for providing voice, video, and data communication among various terminals over the next generation network. This paper discusses a multipoint VoIP implementation with end-point mixing model which can support multipoint conference without a conference bridge. The multipoint VoIP is implemented with SIP (Session Initiation Protocol), and supports STUN (Simple Traversal of UDP Through NATs) since it works in an asymmetric NAT (Network Address Translator) environment. The characteristics of this paper are as follows. It is possible that all terminals in the hierarchical conference don't receive the duplicated media information because we use the end-point mixing model with the new media processing module. And, the paper solves the problem that the hierarchical conference session should be separated into several sessions when a mixing terminal terminates the hierarchical conference session.

• Journal of Korea Game Society
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• v.1 no.1
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• pp.5-16
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• 2001

Recently, Transition to the epoch of world has put an emphasis on the contents that has been emerging as the value of world economy. Consequently the core of industry is moving from IT industry to culture contents industry. Especially Game Industry among the culture contents industry is estimated that it will be the biggest power of influence in size and social influence. Game Industry is one of the high value-added, knowledge-based industries whose market is increasing faster than any other cultural industries. And game industry includes the technology, culture, cultural science and industry. It effectively symbolizes the character of synthetic entertainment industry in comparison with another industry. Also Game Industry is embedding as the superpower industry that competent to draw the whole development of culture industry because game development is intensifying into One-Source Multi-Use. It is important finding of this paper that it is necessary to ensure the competitive power and understand value and character of contents and to project the policy of human power and technology of Game Industry.

• Applied Chemistry for Engineering
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• v.22 no.4
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• pp.343-347
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• 2011

Due to the strong dependence on fossil fuels within the history of human progress, it leads to disaster of the whole world like flood, shortage of water and extinction of the species. In order to curb carbon dioxide emissions, many technologies are being developed. Among them, porous carbon materials have important advantages over other absorbent, such as high surface area, thermal and chemical resistance, low cost, various pore distribution and low energy requirement for their regeneration. Carbon capture and storage (CCS) has attracted the significant research efforts for reducing green house gas emission using several absorbent and process. Moreover, the absorbent are used for the separation of bio mass gas that contains methane which is considered a promising fuel as new green energy resource. In this review, we summarized the recent studies and trend about the porous carbon materials for CCS as well as separation from the biogas.

• Journal of Aquaculture
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• v.17 no.3
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• pp.180-186
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• 2004

This study was carried out to obtain the fundamental data for the mass seedling production of grunt, Hapalogenys nitens in terms of the natural spawning and some characteristics of the eggs spawned. The wild grunt were reared at indoor tanks for three years. The adults spawners were 34.0∼44.0 cm (38.6$\pm$4.0 cm, n=7) in total length, 1.00∼2.23 kg (1.62$\pm$0.50 kg, n=7) in body weight. Spawning were observed 9 times from September 22 to October 1, 2000 and 37 times from August 22 to October 3, 2001, with a water temperature range of 19.8$\pm$28.5$^{\circ}C$. The total number of eggs collected was 2.29${\times}$10$^{7}$ (1.7${\times}$10$^{3}$/ml). The relative proportion of floating eggs to total eggs was 41.7%. The fertilization rate of floating eggs was ranged between 85.0 and 99.9% and the hatching rate was ranged between 2.9 and 93.0%. Fertilized eggs were buoyant and spherical in shape, and were 0.85∼0.98 mm in diameter. Each egg contained 1-5 oil globules which were, 0.18∼0.25 mm in diameter. The incubation time from fertilization to blastodisc formation was 10 minutes, to blastula was 3 hours, and to the hatched larvae at 26$^{\circ}C$ was 20 hours 30 minutes. The newly hatched larvae attained total length of 1.81$\pm$0.18 mm. The time required from fertilization to hatching was 31∼34 hours at 23$^{\circ}C$ and 17∼20 hours at 29$^{\circ}C$.