• Current Photovoltaic Research
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• v.3 no.3
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• pp.97-100
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• 2015

The kesterite $Cu_2ZnSnSe_4$ (CZTSe) thin film solar cells were synthesized by selenization of sputtered Cu/Sn/Zn metallic precursors on Mo coated soda lime glass substrate in Ar atmosphere. Cu/Sn/Zn metallic precursors were deposited by DC magnetron sputtering process with 30 W power at room temperature. As-deposited metallic precursors were placed in a graphite box with Se pellets and selenized using rapid thermal processing furnace at various temperature ($480^{\circ}C{\sim}560^{\circ}C$) without using a toxic $H_2Se$ gas. Effects of Selenization temperature on the morphological, crystallinity, electrical properties and cell efficiency were investigated by field emission scanning electron microscope (FE-SEM) and X-ray diffraction (XRD), J-V measurement system and solar simulator. Further details about effects of selenization temperature on CZTSe thin films will be discussed.

• Fire Science and Engineering
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• v.29 no.2
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• pp.8-12
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• 2015

Performance Based Design is evaluating after each calculatiuon ASET and RSET. Risk informaion values such as heat, smoke, toxic gas etc are extracted by FDS in this study. These Risk informaion values by FDS apply Artisoc (evacuation simulator). Building structure made $60m{\times}65m$, exit number is made 2 positions and people in this building are 50 ramdonly. 20 times (case1~case 20) simulated and analysis evacuees risk by evacuated route positions.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.6
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• pp.209-215
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• 2015

Following the semiconductor industry's growing, various types of toxic gases and caustic chemicals, HF(Hydrofluoric acid), HCI (Hydochloric acid), $H_2O_2$ (Hydrogen peroxide), $H_2SO_4$ (Sulfuric acid), and Piranha, were using on the semiconductor manufacturing process. Therefore many gas leakage accidents that produce huge losses of lives were caused by the processes. This research deeply considers two basic solutions that the necessity of MSDS education on university for reducing damage of lives and protecting life from chemical leak accidents such as a HF accident in Gumi, Korea and the use of GHS, REACH and the comprehension of propriety about using MSDS for keeping safety from conflagrations by released poison chemical materials.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.09a
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• pp.172-185
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• 2009

This paper presents case histories and research projects related to geotechnical challenges at waste landfill sites in Japan. Due to the limitation of inland space available to waste disposal, coastal landfills and the associated containment systems are important considerations, particularly for metropolitan areas. Experimental works on heavy metals mobility using a large column to simulate the redox potential at the coastal landfill sites are introduced. After the closure of landfill sites, they are expected to be utilized as new land space, since new space is difficult to find in urban area. In the redevelopment of such closed landfill sites, there are possibilities of environmental risks, such as generation of toxic gas and leachate, differential settlement of the waste layer, damage to the lining system. Whether the pile installation through the clay layer acting as a landfill bottom barrier is environmentally acceptable or not has been a great concern in the redevelopment of closed waste landfill sites in particular coastal landfill sites. An analytical study to evaluate the cost-effective remedial option for a dumped waste site located along a landslide area, where cut-off wall keyed into the aquitard might elevate groundwater level and thus may not be employed, is presented.

• 한국균학회소식:학술대회논문집
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• 2016.05a
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• pp.35-35
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• 2016

A mycotoxin is a toxic secondary metabolite produced by organisms of the fungus kingdom, commonly known as molds and has been widely contaminated in agricultural products such as grains and cereals. Many methods including high performance liquid chromatography (HPLC) and gas chromatography (GC) have already been proposed and reviewed for mycotoxins. These methods are either expensive or time-consuming due to the complication of sample preparation and pre-concentration before determination. In addition, both methods are unsuitable for the routine screening of large sample numbers. A biosensor is a fictive analytical device that combines a biological component with a physicochemical detector for the detection of an analyte. Biosensors represent a rapidly expanding field, at the present time, with an estimated 60% annual growth rate; the major impetus coming from the health-care industry but with some pressure from other areas, such as food safety and environmental monitoring. Antibodies and aptamers are bioreceptors which have been used in the development of biosensors. There are many kinds of antibodies and aptamers specific to mycotoxin, and antibody (or aptamer)-based biosensors have been successfully developed for the detection of mycotoxin. The biosensors permit the rapid, sensitive, simple, and on-site detection of a range of mycotoxins and can be an alternative method to traditional methods such as HPLC and GC. This presentation provides the development trends of biosensors to mycotoxins and their application to food and agricultural products.

• Polymer(Korea)
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• v.37 no.4
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• pp.478-485
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• 2013

In this study, hydrogels with fast swelling and high absorbent properties were prepared using biopolymers approved as a food additive and their swelling properties were characterized. To improve the swelling properties of conventional hydrogels, we formed gas bubbles using a foaming agent in the process of preparing hydrogels and characterized in terms of equilibrium swelling ratio, swelling kinetics and cytotoxicity. In particular, alginate hydrogels observed by a digital microscope have an open-pore channels structure with the sizes of hundreds micrometers. Also, the cell viability of all hydrogels were found to be much higher than that of poly(acrylic acid).

• Transactions on Electrical and Electronic Materials
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• v.3 no.3
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• pp.34-38
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• 2002

In this paper, efficiency estimation of toxicity fee fire resistance cable experiments was measured smoke density of toxicity free fire resistance polyolefin insulation material and electric field dependence of tree shape in low density polyethylene (LDPE). One of the most serious causes of failure in high-voltage cables, can be an electrical discharge across an internal gab or void in the insulating material. Treeing due to partial discharge is one of the main causes of breakdown in the insulating materials and reduction of the insulation life. Therefore the necessity for establishing a method to diagnose the aging of insulation materials and to predict the breakdown of insulation and research of the fire resistance character has become important. First, we have studied on electric field dependence of tree shape in LDPE about treeing phenomena occurring on the high electrical field. Second, the measurement method is the attenuation quantity of irradiation by smoke accumulating with in a closed chamber due to non-flaming heat decomposition and flaming combustion. A main cause of fire-growth and generating toxic gas when, it bums, should be dealt with great care in life. safety design. The fire gases were occurred carbon monoxide and decomposition than in polyolefin due to incomplete combustion of PVC, which has high content of carbon in chemical compound.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.11 no.1
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• pp.1-6
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• 1999

Nearshore and offshore pipelines are often applied to carry oil, gas, water and combined products. The thermal and pressure gradients of the fluid inside pipeline cause pipeline expansion. This expansion produces stress to connecting structures with pipeline. Should this stress exceeds the yield strength of connecting components or the allowable displacement of the system, a damage can occur. As most pipelines contain hazardous and toxic fluids, the damage usually leads to fatal accidents involving great economic loss as well. Even subsea pipelines can be easily applied to transport liquid type fluid without time and space constraint, they should be designed and maintained carefully to be functional safely during design lifetime. In this paper, various theories estimating pipeline thermal expansion are investigated and the effects of pipe components to expansion are studied.

• Environmental Engineering Research
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• v.10 no.1
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• pp.38-44
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• 2005

Electro-thermal production of white phosphorus(WP, P4) generates substantial amount of highly toxic phossy water and sludges. Because of their high phosphorus contents and lack of reliable processing technology, large tonnages of these hazardous wastes have accumulated from current and past operations in the United States. In this study, two different methods for treatment of phosphorus sludge were investigated. These were bulk removal of WP by physical separation(froth flotation) and transformation of WP to oxyphosphorus compounds by air oxidation in the sludge medium. Kerosene, among other collectors, resulted in selective flotation of WP from the associated mineral gangue. Solvent action of kerosene occurring on the WP surface(by rendering WP particles hydrophobic) might produce the high selectivity of WP. The WP recovery in the froth was 79.3% from a sludge assaying 34.2% of WP. In the oxidation study, air gas was dispersed in the sludge medium by the rapid rotation of the impeller blades. The high level of sludge agitation intensity caused a fast completion of the oxidation reactions and it resulted in the high percentage conversion of WP to PO4-3 with PO3-3 making up almost all portion of oxyphosphorus compounds. The WP analysis on the treated sludge showed that supernatant solution and solid residue contained an average of 4.2 μg/L and 143 ppm respectively from the sludge containing about 26 g of WP. Further investigation will be required on operational factors to better understand the processes and achieve an optimum condition.

• Safety and Health at Work
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• v.9 no.3
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• pp.352-355
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• 2018

Hazardous work zones (i.e., hot, warm, and cold) are typically established by emergency response teams during hazardous materials (HAZMAT) calls but less consistently for fire responses to segment personnel and response activities in the immediate geographic area around the fire. Despite national guidelines, studies have documented the inconsistent use of respiratory protective equipment by firefighters at the fire scene. In this case-series report, we describe warm zone gas levels using multigas detectors across five independent fire incident responses all occurring in a large South Florida fire department. Multigas detector data collected at each fire response indicate the presence of sustained levels of volatile organic compounds in the "warm zone" of each fire event. These cases suggest that firefighters should not only implement strategies for multigas detector use within the warm zone but also include respiratory protection to provide adequate safety from toxic exposures in the warm zone.