• Journal of Radiation Protection and Research
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• 제35권1호
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• pp.6-11
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• 2010

Embodying the safety of radioactive waste disposal requires the relevant safety criteria and the corresponding stylized methods to demonstrate its compliance with the criteria. This paper proposes a conceptual model of risk-based safety evaluation for integrating complex potential radiation exposure situations in radioactive waste disposal. For demonstrating compliance with a risk constraint, the approach deals with important exposure scenarios from the viewpoint of the receptor to estimate the resulting risk. For respective exposure situations, it considers the occurrence probabilities of the relevant exposure scenarios as their probability of giving rise to doses to estimate the total risk to a representative person by aggregating the respective risks. In this model, an exposure scenario is simply constructed with three components:radionuclide release, radionuclide migration and environment contamination, and interaction between the contaminated media and the receptor. A set of exposure scenarios and the representative person are established from reasonable combinations of the components, based on a balance of their occurrence probabilities and the consequences. In addition, the probability of an exposure scenario is estimated on the assumption that the initiating external factors influence release mechanisms and transport pathways, and its effect on the interaction between the environment and the receptor may be covered in terms of the representative person. This integrated approach enables a systematic risk assessment for complex exposure situations of radioactive waste disposal and facilitates the evaluation of compliance with risk constraints.

• Advances in concrete construction
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• 제5권6호
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• pp.563-573
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• 2017

Transparency, excellent toughness, thermal stability and a very good dimensional stability make Polycarbonate (PC) one of the most widely used engineering thermoplastics. Polycarbonate market include electronics, automotive, construction, optical media and packaging. One alternative for reducing the environmental pollution caused by polycarbonate from electronic waste (e-waste), is to use it in cement concretes. In this work, physical and chemical characterization of recycled polycarbonate from electronic waste was made, through the analysis by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), energy dispersive spectroscopy (EDS) and scanning electron microscope (SEM). Then cement concrete was made with Portland cement, sand, gravel, water, and this recycled polycarbonate. Specimens without polycarbonate were produced for comparison purposes. The effect of the particle sizes and concentrations of recycled polycarbonate within the concrete, on the compressive strength and density was studied. Results show that compressive strength values and equilibrium density of concrete depend on the polycarbonate particle sizes and its concentrations; particularly the highest compressive strength values were 20% higher than that for concrete without polycarbonate particles. Moreover, morphological, structural and crystallinity characteristics of recycled polycarbonate, are suitable for to be mixed into concrete.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2004년도 추계학술대회
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• pp.272-273
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• 2004

Filter media are one of themost important choices when bilfiltration is applied. Filter media provide adsorbing microbes with available sites for residence and the residential cells grow to degrade or decompose target waste gases. Up to date, filter media were only qualitatively analyzed. As a quantitative approach to filter material for biofiltration, a simple model based on reaction kinetics and mass action law (Ottengraf's Model in 1983) was presented. Cork, zeolite, and granulated activated carbon were tested in terms of effective surface area, cell covered fraction of adsorbing sites, surface roughness, and pore size distribution. The cell covered fraction, surface roughness and hydrophilicity was found to be closely related to the efficiency of gas degradation in biofiltration. The cork was the best candidate for cell residence and growth in this work.

• International journal of advanced smart convergence
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• 제11권3호
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• pp.72-78
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• 2022

The aim of this research is to improve the effectiveness of digital media advertising because current advertisements -in digital signage - indiscriminately appeals to the general public rather than to a specific target. In order to deliver efficient and customized advertisement information, an IoT human body detection sensor mounted on digital signage detected human faces and then classified them firstly by gender. The digital signage here is a smart digital signage that can analyze facial signals, discriminate them based on patterns, and apply the extracted data by displaying the corresponding information to the user. In addition, by identifying the customer's location approaching the smart digital signage and displaying the optimized content information for the customer's location through an algorithm, the digital signage can dramatize the advertisement Thus, this is a study meant forimproving information efficiency while reducing noise and driving power waste generated from unnecessary digital information reproduction.

• Applied Biological Chemistry
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• 제20권2호
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• pp.228-235
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• 1977

산업폐수가운데 유기성폐수로서 설탕, Ice cream 및 맥주공장폐수등 3종을 택하여 그중에 번식하는 유용한 미생물로서 생장도활성이 큰 효모균주를 분리하고 선정균주에 의한 폐수처리실험한 결과 최적조건하($pH\;4.5{\sim}5.5,\;30{\pm}1^{\circ}C,\;O_2\;0.2\;v/v/min.,\;600{\sim}900\;r.p.m.$) 다음과 같은 결과를 얻었다. 1) 분리동정한 Candida curvata는 3종의 식품공장폐수에 배양실험한 결과, 무기영양원 첨가시 생육이 양호하여 폐수처리에 이용가능한 균주이었다 2) 폐수의 멸균조작의 유무는 설탕및 맥주공장폐수의 경우, 배양결과에 큰 차이가 없었으며, 다만 Ice cream공장폐수의 경우 비멸균시 induction period가 훨신 장시간이었다. 3) 비멸균배양시 최대 비증식속도는 설탕, Ice cream 및 맥주공장폐수 순으로 각각 0.5, 0.5 및 1.0/hr이었다. 4) 접종량을 늘리면, 비멸균시에서도 induction period가 짧아지고 따라서 배양시간이 단축되었다. 5) 건조균체량은 설탕, 맥주 및 Ice cream공장폐수 순으로 폐수 $1{\ell}$당 각각 175mg, 628mg 및 857mg이었고, 균체의 조란백함량은 같은 순으로 각각 52%, 54% 및 54%이었다. 6) BOD 제거율은 위의 5)항과 같은 순으로 각각 49%, 80%, 및 64%이었다.

• 한국환경보건학회:학술대회논문집
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• 한국환경보건학회 2005년도 국제학술대회
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• pp.359-364
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• 2005

The possible use of milk factory waste water as fermentation media for the production of citric acid by cells of Aspergillus niger ATCC 9142 has been investigated. The addition of $Mn^{2+}$, $Fe^{2+}$ and $Cu^{2+}$ to a medium promoted the citric acid production steadily, but addition of another metal ion $Mg^{2+}$decreased the citric acid production. The concentrations of citric acid were marked up to 7.2g/1 and 16.5g/l in a batch bioreactor by A. niger ATCC 9142 with 50g/1 and 100g/l of reducing sugar concentration in milk factory waste water, respectively.

• Journal of the Korean Wood Science and Technology
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• 제46권6호
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• pp.645-655
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• 2018

The use of wood waste as substrate for plant growth exemplifies a strategy for turning waste into resources. The overall objective of this research was to evaluate the effects of wood-based growing media on plant cover in a slope area. Moreover, we tried to find out what physicochemical properties affect plant cover on a slope. For treatments, we tested natural soil, soil mixed with wood-based growing medium (1:1, w/w), and wood-based growing medium by itself. Physical and chemical characteristics were evaluated after four months from the date of treatment application to the experimental slope site. Soil coverage with seedlings of Lespedeza cyrtobotrya was measured for plant growth evaluation. Physicochemical properties were altered by mixing the natural soil with wood-based growing medium. Particularly, soil moisture and organic matter contents were significantly changed in soils treated with wood-based growing medium compared to soil alone. We confirmed that plant coverage rate was high when wood-based growing medium was mixed with the natural soil. There was a significant linear relationship between moisture content and CEC (Cation Exchange Capacity) of all growth media tested and plant coverage. This result was expected, as moisture content tends to increase with organic matter content, such as in wood-based growing medium. In conclusion, the high moisture content of the wood-based growing medium was considered effective for plant growth in the experimental slope site, and this wood-based growing medium provides a means to improve the harmony between the slope and the surrounding environment.

• Mycobiology
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• 제29권3호
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• pp.160-163
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• 2001

Sikhae is a Korean traditional beverage of saccharified rice. Its factory waste(SFW) is usually thrown away instead of being used. We developed a cheap substrate of SFW for use in liquid spawn that is known for its higher fruit body yields than grain spawn in sawdust cultivation. Mycelia of Lentinula edodes ASI 3046, which is regarded as the most suitable strain for sawdust cultivation, were cultured on six kinds of previous known media and SFW. As the seven kinds of media were applied, a Sikhae Factory Waste(SFW) was most excellent in growth. The dried mycelial weight in SFW was almost four times as much as that in the other media. In the flask culture, optimum culture conditions for the mycelial growth were obtained after 13 days of cultivation at media volume of 100 ml, 100 rpm, initial pH 4.5, and $25^{\circ}C$. The best mycelial growth was observed when $MgSO_4{\cdot}7H_2O$ and D-sucrose were added as a supplement in SFW. SWM must be a remarkable medium for L. edodes because of its simple preparation and low cost.

• 한국물환경학회지
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• 제24권4호
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• pp.436-441
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• 2008

This work experimentally determined the effect of operating parameters such as temperature and solid retention time (SRT) on the phosphorus removal of municipal wastewater with waste-tire media. The experiments were carried out in pilot-scale moving bed biofilm reactor filled at a 0.15 filling ratio with the media. Total phosphorus (TP) removal efficiency was $91{\pm}5$, $75{\pm}16$, and $59{\pm}14%$ at the temperature of 9~10, 10~20, and $20{\sim}26^{\circ}C$, respectively. TP removal efficiency was $71{\pm}17$, $74{\pm}16$, $74{\pm}16$, and $68{\pm}18%$ at the SRT of 3.5~5, 5~10, 10~15, and 15~20 days, respectively. At the nitrate concentration of 1~3, 3~6, and 6~9 mg/L, TP removal efficiency was $82{\pm}9$, $68{\pm}18$, $47{\pm}7%$, respectively. The concentration of total phosphorus in the effluent was $0.1{\sim}1.8(0.8{\pm}0.4)mg/L$ regardless of operating conditions, which meets Korean phosphorus limit value, 2 mg/L, for discharge into receiving waters.

• 한국지하수토양환경학회지:지하수토양환경
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• 제29권1호
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• pp.72-83
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• 2024

Most of the slags generated from steel-making industry in Korea are recycled into media-contact aggregates such as fill and cover materials. For their use as media-contact aggregates, the slags must meet not only the waste quality criteria, but also the Daphnia magna acute toxicity test criteria. In this study, Korean Leaching Test ES 06150.e (Korea), Japanese Leaching Test JIS K 0058-1(Japan), Detuch Leaching Test DIN 19529 (Germany), Toxicity Characteristic Leaching Procedure (USA) were conducted for batch leaching test of slags from 6 Korean steel-making companies. In addition, Korean Standard up-flow percolation test (ES 06151.1) mimicking field conditions was conducted to assess the impact of the slag leachate on the surrounding environment indirectly. Heavy metals such as Cr⁶⁺ and Zn²⁺ were detected from both extractant and leachate samples, but all of them did not exceed waste quality criteria of each country. However, Daphnia magna acute toxicity tests using the leachate samples from up-flow percolation test with slag alone and slag/natural soil conditions exceeded ecotoxicity standard (TU=2) due to their high pH (11.3-12.5). After neutralizing the pH of the slag leachate to 6.5~8.5, the Daphnia magna mortality and immobilization were reduced to satisfy ecotoxicity standard. As the reducing pH of slag leachate would be extremely difficult, appropriate recycling management considering the physicochemical characteristics of he slags should be stuided further.