• Title/Summary/Keyword: waste paper

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Emission Characteristics of Mercury in Zn Smelting Process (아연제련시설에서의 수은 배출특성)

  • Park, Jung-Min;Lee, Sang-Bo;Kim, Hyung-Chun;Song, Duk-Jong;Kim, Min-Su;Kim, Min-Jung;Kim, Yong-Hee;Lee, Sang-Hak;Kim, Jong-Chun;Lee, Suk-Jo
    • Journal of Korean Society for Atmospheric Environment
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    • v.26 no.5
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    • pp.507-516
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    • 2010
  • Stationary combustion sources such as coal-fired power plants, waste incinerators, industrial manufacturing, etc. are recognized as major sources of mercury emissions. Due to rapid economic growth, zinc production in Korea has increased significantly during the last 30 years. Total zinc production in Korea exceeded 739,000 tons in 2008, and Korea is currently the third largest zinc producing country in the world. Previous studies have revealed that zinc smelting has become one of the largest single sectors of total mercury emissions in the World. However, studies on this sector are very limited, and a large gap in the knowledge regarding emissions from this sector needs to be bridged. In this paper, Hg emission measurements were performed to develop emission factors from zinc smelting process. Stack sampling and analysis were carried out utilizing the Ontario Hydro method and US EPA method 101A. Preliminary data showed that $Hg^0$ concentrations in the flue gas ranged from 4.56 to $9.90\;{\mu}g/m^3$ with an average of $6.40\;{\mu}g/m^3$, Hg(p) concentrations ranged from 0.03 to $0.09\;{\mu}g/m^3$ with an average of $0.04\;{\mu}g/m^3$, and RGM concentrations ranged from 0.23 to $1.17\;{\mu}g/m^3$ with an average of $6.40\;{\mu}g/m^3$. To date, emission factors of 7.5~8.0 g/ton for Europe, North America and Australia, and of 20 or 25 g/ton for Africa, Asia and South America are widely accepted by researchers. In this study, Hg emission factors were estimated using the data measured at the commercial facilities as emissions per ton of zinc product. Emission factors for mercury from zinc smelting pross ranged from 4.32 to 12.96 mg/ton with an average of 8.31 mg/ton. The emission factors that we obtained in this study are relatively low, considering Hg contents in the zinc ores and control technology in use. However, as these values are estimated by limited data of single measurement of each, the emission factor and total emission amount must be updated in future.

DETERMINATION OF MOISTURE AND NITROGEN ON UNDRIED FORAGES BY NEAR INFRARED REFLECTANCE SPECTROSCOPY(NIRS)

  • Cozzolino, D.;Labandera, M.;Inia La Estanzuela
    • Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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    • 2001.06a
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    • pp.1620-1620
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    • 2001
  • Forages, both grazed and conserved, provide the basis of ruminant production systems throughout the world. More than 90 per cent of the feed energy consumed by herbivorous animals world - wide were provided by forages. With such world - wide dependence on forages, the economic and nutritional necessity of been able to characterize them in a meaningful way is vital. The characterization of forages for productive animals is becoming important for several reasons. Relative to conventional laboratory procedures, Near Infrared Reflectance Spectroscopy (NIRS) offers advantages of simplicity, speed, reduced chemical waste, and more cost-effective prediction of product functionality. NIR spectroscopy represents a radical departure from conventional analytical methods, in that entire sample of forage is characterized in terms of its absorption properties in the near infrared region, rather than separate subsamples being treated with various chemicals to isolate specific components. This forces the analyst to abandon his/her traditional narrow focus on the sample (one analyte at a time) and to take a broader view of the relationship between components within the sample and between the sample and the population from which it comes. forage is usually analysed by NIRS in dry and ground presentation. Initial success of NIRS analysis of coarse forages suggest a need to better understand the potential for analysis of minimally processed samples. Preparation costs and possible compositional alterations could be reduced by samples presented to the instrument in undried and unground conditions. NIRS has gained widespread acceptance for the analysis of forage quality constituents on dry material, however little attention has been given to the use of NIRS for chemical determinations on undried and unground forages. Relatively few works reported the use of NIRS to determine quality parameters on undried materials, most of them on both grass and corn silage. Only two works have been found on the determination of quality parameters on fresh forages. The objectives of this paper were (1) to evaluate the use of NIRS for determination of nitrogen and moisture on undried and unground forage samples and (2) to explore two mathematical treatments and two NIR regions to predict chemical parameters on fresh forage. Four hundred forage samples (n: 400) were analysed in a NIRS 6500 instrument (NIR Systems, PA, USA) in reflectance mode. Two mathematical treatments were applied: 1,4,4,1 and 2,5,5,2. Predictive equations were developed using modified partial least squares (MPLS) with internal cross - validation. Coefficient of determination in calibration (${R^2}_{CAL}$) and standard error in cross-validation (SECV) for moisture were 0.92 (12.4) and 0.92 (12.4) for 1,4,4,1 and 2,5,5,2 respectively, on g $kg^{-1}$ dry weight. For crude protein NIRS calibration statistics yield a (${R^2}_{CAL}$) and (SECV) of 0.85 (19.8) and 0.85 (19.6) for 1,4,4,1 and 2,5,5,2 respectively, on a dry weight. It was concluded that NIRS is a suitable method to predict moisture and nitrogen on fresh forage without samples preparation.

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Microbial Conversion of Woody Waste into Sugars and Feedstuff (II) - Production of Cellulolytic Enzymes from Aspergillus fumigatus and Saccharification of Popla Wood (미생물(微生物)에 의한 목질자원(木質資源)의 당화(糖化) 및 사료화(飼料化)에 관(關)한 연구(硏究) (II) - Aspergillus fumigatus KC-1으로부터 섬유소 분해 효소의 생산 및 현사시나무의 효소가수분해)

  • Chung, Ki-Chul;Huh, Jeong-Weon;Myung, Kyu-Ho;Kim, Yoon-Soo
    • Journal of the Korean Wood Science and Technology
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    • v.15 no.4
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    • pp.18-25
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    • 1987
  • The cellulolytic activities of Aspergillus fumigatus KC-1 was investigated, which showed the most active producer of cellulase among the 256 strains of cellulose-decomposing microorganisms screened in our laboratory. All the examined cellulolytic activities (filter paper-, Avicel-, cotton-, CMC-, salicin- and xylansaccharifying activity) in a culture of A. fumigatus KC-1 grown on 1% popular sawdust pretreated with peroxide alkaline reached a maximum within 4-5 days. The optimum pH and temperature for the enzymatic activity was found to be pH 4.5 and $60^{\circ}C$ respectively. The sawdust of poplar wood delignified with 1% NaOH and 20% peracetic acid succesively recorded the highest hydrolysis rate in the tests of enzymatic saccharification. The major end product of hydrolysis of poplar wood with the cellulolytic enzymes obtained from A. fumigatus KC-1 was glucose with small amount of cellobiose and xylose. It can be concluded from these results that A. fumigatus KC-1 is an advantagous source of a cellulase that is capable of hydrolyzing cellulose to glucose rapidly. The influence of degree of delignification, substrate size and its concentration on the rate of hydrolysis of poplar wood was also discussed.

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Carbonation Properties of Recycled Aggregate Concrete by Specified Concrete Strength (설계기준 강도별 순환골재 콘크리트의 탄산화 특성)

  • Lee, Jun;Lee, Bong-Chun;Cho, Young-Keun;Park, Kwang-Min;Jung, Sang-Hwa
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.5 no.1
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    • pp.85-93
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    • 2017
  • This paper presents mechanical properties and carbonation behavior of the recycled aggregate concretes(RAC) in which natural aggregate was replaced by recycled coarse aggregate and fine aggregate by specified concrete strength levels(21, 35, 50MPa). A total of 18 RAC were produced and classified into six series, each of which included three mixes designed with three specified concrete strength levels of 21MPa, 35MPa and 50MPa and three recycled aggregate replacement ratios of 0, 50 and 100%. Physical and mechanical properties of RAC were tested for slump test, compressive strength, and carbonation depth. The test results indicated that the slump of RAC could be improved or same by recycled coarse aggregate replacement ratios, when compared with natural aggregate. But slump of RAC was decreased as the recycled fine aggregate replacement ratios increase. Also, the test results showed that the compressive strength was decreased as the recycled aggregate replacement ratios increased and it had a conspicuous tendency to decrease when the content of the recycled aggregate exceeded 50%. Furthermore, the result indicated that the measured carbonation depth increases by 40% with the increase of the recycled aggregate replacement. In the case of the concrete having low level compressive strength, the increase of carbonation depth tends to be higher when using the RCA. However, the trend of carbonation resistivity in high level compressive strength concrete is similar to that obtained in natural aggregate concrete. Therefore, an advance on the admixture application and mix ratio control are required to improve the carbonation resistivity when using the recycled aggregate in large scale.

An Automated Sharing Scheme of CAD Tools and License Resources Based on Directory Service (디렉토리 서비스에 기반한 CAD 툴 및 라이센스 자원의 자동화된 공유 방식)

  • Jung Sung-Heon;Yim In-Sung;Jhang Kyoung-Son
    • The KIPS Transactions:PartA
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    • v.13A no.1 s.98
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    • pp.27-34
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    • 2006
  • Designers should know CAD tool/license information such as available number of licenses or tools, types, and configuration methods to use CAD tools properly in their group. Usually, this information is provided by managers who administrate CAD tool and license servers in the specific design group. In the previous CAD tool/licenses sharing methods, designers have to get CAD tool/license information manually and setup the environments with their own hands. n a new designer comes into the design working group, the designer wastes unnecessary design time, because of these processes. As a result, designer's poductivity and utilization of CAD tools will decrease Besides, managers also waste their time and effort, since they should provide CAD tool/license information manually to each designer. In this paper, we present an automated scheme to share CAD tool/license information based on directory service. The proposed methods automate the communication processes between managers and designers that minimze unnecessary time to share CAD information. In addition, as this system maintains the consistency of CAD information automatically that remove the repeated work of managers and designers, it improves the enciency of sharing. Besides, it automates the license configuration steps using prof(y Last, we offer Executable Proxy which is proper for thin CAD application. We believe this scheme will reduce designers and managers' time and effort as well as maximize the utilization of CAD tools.

An Efficient IPTV Distribution Network by Packet Transport System (Packet Transport System에 의한 효율적인 IPTV 분배망 구축 방안)

  • Jang, Jin-Hee;Park, Seung-Kwon;Roh, Jin-Young;Noh, Francis Tai
    • Journal of Broadcast Engineering
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    • v.12 no.2
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    • pp.80-92
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    • 2007
  • IPTV Services that is representative union service of broadcasting and telecommunication need guarantee of QoS, efficiency of multicasting, and hish bandwidth on the network. Because typical TDM based metro transport network was designed by transporting fixed voice traffic with stable and recovering method, it has a defect of bottleneck and a waste of bandwidth for acceptance of data traffic with burst feature and then all of data are treated equally at the transport network because it cannot classify between advanced high end service and best effort low end service. for completely resolving this kind of problem about increasing burst traffic and QoS issues, firstly we need to new design for transport network. This paper presents transformation method from TDM based metro transport network to packet based transport network and advantage and effectiveness of packet based transport network and also indicates technical factor and characters about method of packet transport system. As a result of research, the Packet Transport System, which is a transmission network for packet delivery, take in not only a specific character of legacy TDM but QoS, Multicast and high bandwidth, then, it is able to keep an effective bandwidth and a stabilized performance of packet transmissions. Additionally, if a fault be occurred on an optical link, the system is able to guarantee a differential QoS by an each service class using an algorithm to make certain of a traffic existence and contain a protective mechanism.

Manufacture and Performance Evaluation of Medium-density Fiberboard Made with Coffee Bean Residue-Wood Fiber (커피박과 목섬유를 이용한 중밀도섬유판의 제조 및 성능 평가)

  • Yang, In;Lee, Kwang-Hyung;Oh, Sei-Chang
    • Journal of the Korean Wood Science and Technology
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    • v.41 no.4
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    • pp.293-301
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    • 2013
  • This study discusses the feasibility of coffee bean residue as a raw material of medium-density fiberboard (MDF). In this relation, the effect of coffee bean residue known as an absorbent material on the physical and mechanical properties of MDF manufactured at its different addition level. Coffee bean residue which is a by-product of coffee mill and large amount of waste left over after processing for instant coffee was added at the level of 3, 6, and 9% on dry basis and urea formaldehyde resin was used as the adhesive. The MDF made with mixture of wood fiber and coffee bean residue was tested for physical and mechanical properties as well as formaldehyde emission. The bending strength and internal bonding strength of the MDF made with mixture of wood fiber-coffee bean residue were higher than that of the KS standard in randomized mat structure type, but not in layered mat structure type. Also, the physical properties of MDF made with mixture of wood fiber-coffee bean residue showed a considerable improvement in thickness swelling over the commercial MDF. More importantly, the formaldehyde emission rate of MDF made with mixture of wood fiber-coffee bean residue met the KS standard and was close to that of commercial MDF. These results showed the feasibility of coffee bean residue as a raw material for the production of environmentally-friendly MDF. Additional works on adhesive-coffee bean compatibility, improvement of moisture absorption effect and reduction the formaldehyde emission rate by carbonization of coffee bean residue may be required.

Conversion Characteristics of MSW at Various Pyrolytic and Oxidative Conditions (열분해 및 산화조건에서 MSW의 물질전환특성 연구)

  • Byen, Kyong-Hee;Lee, Yong-Jin;Yoon, Kyoon-Duk;Dong, Jong-In
    • Journal of Korean Society of Environmental Engineers
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    • v.22 no.11
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    • pp.1955-1968
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    • 2000
  • Thermal gravimetric change characteristics and gas phase product - CO, NO, $NO_2$, VOCs - generated in the process of pyrolysis and oxidation. were investigated with variation of process parameters including furnace reactor temperature both in pyrolytic and oxidative conditions. For the thermal gravimetric change characteristics. paper and wood were mainly decomposed at lower temperatures and they had similar thermal gravimetric change trend due to their similar compositions; plastics were mainly decomposed at higher temperatures; in the case of textile. natural compounds were decomposed at lower temperatures and synthetic compounds at relatively higher temperatures; food was decomposed in the wide range of temperatures possibly due to their different kinds of components. For the analysis results of gas phase product. the concentrations of NO, $NO_2$ were detected at higher level at the oxidative conditions than at the pyrolytic conditions except that of CO, which is due to complete combustion with sufficient oxygen at the oxidative condition; food gave off CO, NO, $NO_2$ more than the other wastes. VOCs were emitted more at the pyrolytic conditions than at the oxidative conditions.

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A study on the risk and settlement evaluation of a shield TBM excavated in soft marine sedimentary soils (해저 연약 퇴적층 지반 쉴드 TBM 위험요인 평가 및 장비 침하에 관한 연구)

  • You, Kwang-Ho;Park, Chi-Myeon
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.18 no.4
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    • pp.355-364
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    • 2016
  • Recently, a 3,250 meter-long tunnel was constructed beneath the sea bed formed of composite sedimentary soils to transport reusable waste heat gas of industrial complex in the west coast of Korea. Some risks such as machine settlement always exist due to the uncertainties of geological and construction factors during the subsea shield TBM tunnelling. In this construction site, the deviation of tunnel alignment caused by shield TBM settlement was occurred during excavation. It was examined that the lack of bearing capacity of soft clay was a main cause. This paper evaluates the risk of shield TBM tunnelling considering the ground conditions. Correlation between machine settlement and its advance rate was evaluated through the analytical equation in which bearing capacity is considered and a 3-D numerical analysis which can simulate the TBM advance condition (in other words, the dynamic condition). It was found out that a shield TBM could settle due to the insufficient bearing capacity of soft clay layers. In order to prevent such the problem, the best advance rate proper to the ground characteristics is needed to be applied. In the ground conditions of the section of interest, it was turned out that if the shield TBM advance rate was maintained between 35 mm/min and 40 mm/min, the machine settlement could be avoided.

The QoS Filtering and Scalable Transmission Scheme of MPEG Data to Adapt Network Bandwidth Variation (통신망 대역폭 변화에 적응하는 MPEG 데이터의 QoS 필터링 기법과 스케일러블 전송 기법)

  • 유우종;김두현;유관종
    • Journal of Korea Multimedia Society
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    • v.3 no.5
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    • pp.479-494
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    • 2000
  • Although the proliferation of real-time multimedia services over the Internet might indicate its successfulness in dealing with heterogeneous environments, it is obvious, on the other hand, that the internet now has to cope with a flood of multimedia data which consumes most of network communication channels due to a great deal of video or audio streams. Therefore, for the purpose of an efficient and appropriate utilization of network resources, it requires to develop and deploy a new scalable transmission technique n consideration of respective network environment and individual clients computing power. Also, we can eliminate the waste effects of storage device and data transmission overhead in that the same video stream duplicated according to QoS. The purpose of this paper is to develop a technology that can adjust the amount of data transmitted as an MPEG video stream according to its given communication bandwidth, and technique that can reflect dynamic bandwidth while playing a video stream. For this purpose, we introduce a media scalable media decomposer working on server side, and a scalable media composer working o n a client side, and then propose a scalable transmission method and a media sender and a media receiver in consideration of dynamic QoS. Those methods proposed her can facilitate an effective use of network resources, and provide multimedia MPEG video services in real-time with respect to individual client computing environment.

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