Volatile organic compounds (VOCs) can adversely affect human and plant health by generating secondary pollutants such as ozone and fine particulate matter, through photochemical reactions, necessitating systematic management. This study investigated the distribution characteristics of gaseous VOCs in ambient air, with a focus on interpreting data from a photochemical pollution perspective. This paper analyzed the presence and concentration distribution of VOCs in industrial areas, identifying toluene, m-xylene, p-xylene, and n-octane as the most frequently detected components. Particularly, toluene was found to significantly contribute to the formation of ozone and fine particulate matter, highlighting the need for stricter regulation of this compound. Although n-octane and styrene were present in relatively low concentrations overall, their significant contributions to ozone generation and secondary organic aerosol formation, respectively, emphasize their importance in air pollution management.
This study conducted an investigation into the effects of fruit type and cultivation practices (organic and conventional) on soil characteristics and soil arthropod communities within apple, blueberry, grape, peach, and pear orchards. The collection of soil arthropod communities was achieved through the utilization of pitfall traps, with concurrent measurements taken for soil moisture content, electrical conductivity, and temperature. The findings of this study unveiled substantial impacts attributed to fruit type and cultivation practices on soil characteristics. Specifically, within organic apple orchards, discernibly higher levels of soil moisture content, electrical conductivity, and temperature were observed when compared to their conventional counterparts. The investigation into soil arthropod communities yielded a total of 1,527 individuals, classified in to five phyla and 15 orders. The range of abundance, species richness, and diversity indices varied across conventional and organic orchards. Cultivation practices were found not to exert a significant influence on soil arthropod community characteristics. However, Non-metric Multidimensional Scaling (NMDS) analysis indicated a significant differentiation in soil arthropod community structure based on cultivation practices. This study underscores the importance of considering vegetation structure and environmental characteristics that may influence soil arthropod communities comprehensively when assessing the impact of cultivation practices on soil arthropods. Furthermore, it emphasizes the need to account for both the characteristics and structure of soil arthropod communities in understanding the implications of cultivation practices on these organisms.
Various types of solidifying materials are used to stabilize and solidify low and intermediatelevel radioactive dispersible waste. Portland cement is generally used to solidify various radioactive wastes because its facilities and processes are simple, less dangerous, and it has excellent compressive strength after curing compared to other materials. However, it is difficult to use Portland cement in radioactive waste containing highly water-soluble harmful substances such as sodium fluoride because it is prone to leaching harmful ingredients in immersion tests due to its low water resistance. In this study, solidification was achieved using an organic-inorganic hybrid solidifying binders consisting of inorganic binders such as Portland cement, blast furnace slag powder, silica fume, and organic binders such as epoxy resin. This material was then compared with a solidification material made of Portland cement alone. The mixing ratio of inorganic binders, water, and organic binders to simulated waste is 35%, 20%, and 25%, respectively. The mixing ratio of inorganic binders and water when using only Portland cement for simulated waste is 100% and 80%, respectively. The mixed paste was poured into a cylinder mold (Φ 5 × 10 cm) to seal the upper part, cured at room temperature for 28 days to produce a solidification specimen, and then subjected to various tests were performed, including compressive strength, immersion compressive strength, hydration peak temperature, length change, and immersion weight change. The compressive strength of the organic-inorganic hybrid solidification test was 13-17 MPa, the immersion compressive strength was 15-18 MPa, the hydration peak temperature was 33-36°C, the length change rate was -0.086%, and the immersion weight change rate was –2.359%. The compressive strength of the Inorganic solidification test using only Portland cement was 16-18 MPa, the immersion compressive strength was 20-21 MPa, the hydration peak temperature was 23-25°C, the length change rate was -0.150%, and the immersion weight change rate was -5.213%. The compressive strength and immersion compressive strength of the organic-inorganic hybrid solidification materials were slightly lower compared to those of Portland cement solidification materials, they still met the compressive strength standard of 7-12 MPa, taking into consideration the strength reduce and economic feasibility of the core drill process. Furthermore, it indicates that the rates of change in length and immersion weight decreased to about 1% and 5%, suggesting an improvement in water resistance. The above results suggest that applying the organic-inorganic hybrid solidification method to radioactive waste treatment can effectively improve water resistance and help secure long-term stability.
유기농 생태농업단지 논에서 출현하는 수서곤충의 생태자원 분포 특성을 비교하고자 유기농 단지 논에 둠벙 이 있는 조건과 둠벙이 없는 조건에서의 수서곤충상을 조사하여 관행 논의 분포 특성을 비교하였다. 수서곤충 출현은 둠벙이 있는 유기농 논 5목 15과 26종 413개체, 둠벙이 없는 유기농 논 5목 14과 22종 236개체, 관행 논 5목 11과 16종 155개체로 유기농 논에서 관행 논에 비해 수서곤충의 출현 과, 종 및 출현 개체수가 많았고, 유기농 논에서도 둠벙이 있는 조건에서 종수 및 개체수가 많음을 확인하였다. 특히 잠자리목의 경우 유기농 논 4과 8종 134개체, 둠벙이 없는 유기농 논 3과 5종 35개체, 관행 논 2과 4종 12개체로 전체 출현 종의 발생특성과 유사한 경향을 보였는데, 유기농 재배의 특성상 농약의 피해로부터 수서곤충에 안전한 환경이 조성된 점과 둠벙의 담수 및 다양한 수서생물의 발생으로 수서곤충의 서식조건에 유리하게 작용되었다고 보인다. 반면 파리목에서는 둠벙이 있는 유기농 논 3과 3종 18개체, 둠벙이 없는 유기농 논 3과 3종 25개체로 관행 논 2과 2종 24개체보다 발생양상이 다른 수서곤충에 비해 상대적으로 낮고, 관행 논보다 깔다구류의 개체수 19개체보다 각각 6개체, 12개체로 적게 출현한 점에서 유기농 재배유형과 둠벙의 서식처 제공이 수서곤충의 출현 및 분포에 건전성을 조장하는 방안이라고 판단된다.
유기농 논이용 콩-밀 생산체계에서 재배유형별 밀 파종 전 경운여부에 따라 경운/무경운 처리, 콩 재배시 비닐 피복 여부에 따라 피복/무피복 처리, 논의 생태적 개선 여부에 따라 개선/대조구 처리로 시험구를 조성하여 밀 재배 중 곤충자원의 출현 및 분포특성을 조사 비교하였다. 출현 곤충의 총 종수는 20종으로 경운 14종, 무경운 14종으로 차이는 없었고 피복 14종, 무피복 16종이었으며 개선구 18종, 대조구 13종으로 개선처리에서 곤충 출현 종수가 많았다. 출현 곤충의 총개체수는 경운 124개체, 무경운 76개체로 경운처리에서 많았고, 피복 100개체, 무피복 100개체로 차이가 없었으며 경운-무피복-개선에서 40개체로 가장 많았다. 유기농 밀에 피해를 주는 해충 으로 노린재류는 갈색날개노린재가 가장 많이 발생하였고, 메추리노린재, 시골가시허리노린재도 출현하였으 며 재배유형별 발생 개체수는 경운 81마리, 무경운 39마리로 경운에서 많았고, 무경운-피복-대조(7) = 무경운-무 피복-대조(7) < 무경운-무피복-개선(9) < 경운-피복-개선(12) < 경운-무피복-대조(13) < 무경운-피복-개선(16) < 경운-피복-대조(27) < 경운-무피복-개선(29) 순으로 발생하였다.
A large amount of small and medium-sized metal waste is generated during the decommissioning of nuclear power plants (NPPs). Metal waste is mostly contaminated with low-level radioactive, so it needs decontamination for self-disposal and recycling. A large amount of Organic Decontamination Liquid Waste during decontamination will be generated. The generated organic liquid waste is low in concentration, so the decomposition efficiency is low in the decomposition process. A conditioning process is necessary to concentrate at a high concentration. For effective treatment for Organic Decontamination Liquid Waste, the composition of organic liquid waste and conditioning process were analyzed. Organic acids, metal ions, radioactive nuclides, surfactants, etc. are present in the Organic Decontamination Liquid Waste, and suspended solids are sometimes generated by various reactions. According to previous studies, the concentration of organic acids including surfactants obtained results from several tens of ppm to a maximum of 1,000 ppm, so the maximum value of 1,000 ppm was assumed. For the composition and total amount of metal ions, the average value (52.7wt% Fe, 16.3wt% Ni, 15.1wt% Cr, 15.9wt% Mn) of the distribution of metal species removed by the actual decontamination process is applied, and the total amount is 1,000 ppm was assumed. As for the radionuclides, only 60Co and 137Cs, which are expected to be mainly present, were considered, and 60Co was assumed to be 2,000 Bq/g and 137Cs to be 360 Bq/g by referring to the literature. The amounts of suspended solids were assumed to be 500 ppm by referring to the characteristics of the liquid waste generated in the decontamination process of the NPPs. Based on the estimated value, a reaction formula was established and a simulated Organic Decontamination Liquid Waste was prepared. As a result of measurement using an analysis device, the composition of the estimated and simulated Organic Decontamination Liquid Waste had similar values. The conditioning and treatment process largely consists of pretreatment, conditioning, decomposition processes. Organic Decontamination Liquid Waste goes through a pretreatment process to remove impurities with large particles. In the conditioning process, treated water that has passed through the UF/RO membrane system is discharged into the environment. At this time, Concentrated water goes through a decomposition process for processing the Organic Decontamination Liquid Waste, and is discharged to the environment through a secondary RO membrane system. The conditioning process is the low-concentration Organic Decontamination Liquid Waste in the UF membrane system is forming a micelles in an RO membrane system, concentrating it to a high concentration and then go through a recirculation process in the UF membrane system. An experiment was conducted to confirm whether the concentration of surfactants occurred during the conditioning process. As a result of the experiment confirmed that the highly concentrated surfactant formed micelles and was filtered out in the UF membrane system.
The purpose of this study is to analyze the organic forms, expressions, and characteristics of Alexander McQueen’s fashion design and to present various materials for understanding and utilizing this organic design style. The criteria for organic design expressions and characteristics were classified through a literature review, and the organic design characteristics of Alexander McQueen’s fashion were then analyzed. The results are as follows: First, the morphological characteristics of nature’s forms are used as objects in Alexander McQueen’s fashions to represent organic characteristics. Second, abstraction through the application of organic forms means creating an abstract representation of the object being represented. Abstracting organic forms occurs by partially modifying the structural features of the human body to show characteristics or by visualizing these characteristics within the surface of the natural object. Third, continuity through the expression of the formation process of organisms is characteristic of the expression of the gradual growth of organisms; this reinterpretation is based on the concept that the internal elements of natural objects affect their external forms. Fourth, the structure of using natural materials, as well as regional and cultural characteristics, is shown in the designs through use of the physical characteristics of expressions and materials that use natural elements. Fifth, symbolism through subjective thinking implies that the element of nature that an object expresses is the element that appears in nature; this includes created organisms along with environmental factors. These characteristics are best demonstrated in fashion designs that express themselves through creativity.
본 연구에서는 CO2 가스 배출 저감 및 선박 폐열 회수 증대를 목적으로 선박 배기로 버려지는 폐열을 전기로 변환하는 ORC(Organic Rankine Cycle) 발전에 대해 시뮬레이션을 통한 냉매별 효율을 보여주고 있다. 상대적으로 고온인 배기가스의 폐열과 상대적으로 저온인 냉각해수를 이용하여 Aspen HYSYS 11을 이용하여 시뮬레이션을 수행하였다. 해수냉각 ORC 발전시스템의 시뮬레이션 결과, 작동유체 효율은 R717 냉매가 2.86 %로 가장 높았고, 다음 순으로 R152a, R134a, R143a, R125a로 나타났다.
This paper proposes a mathematical model that can calculate the luminescence characteristics driven by alternating current (AC) power using the current-voltage-luminance (I-V-L) properties of organic light emitting devices (OLED) driven by direct current power. Fluorescent OLEDs are manufactured to verify the model, and I-V-L characteristics driven by DC and AC are measured. The current efficiency of DC driven OLED can be divided into three sections. Region 1 is a section where the recombination efficiency increases as the carrier reaches the emission layer in proportion to the increase of the DC voltage. Region 2 is a section in which the maximum luminous efficiency is stably maintained. Region 3 is a section where the luminous efficiency decreases due to excess carriers. Therefore, the fitting equation is derived by dividing the current density and luminance of the DC driven OLED into three regions, and the current density and luminance of the AC driven OLED are calculated from the fitting equation. As a result, the measured and calculated values of the AC driving I-V-L characteristics show deviations of 4.7% for current density, 2.9% for luminance, and 1.9% for luminous efficiency.
The emission of particulate matter and volatile organic compounds (VOCs) from a motor vehicle painting booth was quantitatively evaluated. Most particulate matter was emitted during the spraying process, in which the PM10 concentration was 16.5 times higher than that of the drying process. When the paint was being sprayed, the particles with a diameter of 1.0~2.5 μm accounted for 39.4% and particles greater than 2.5 μm in diameter accounted for 30.6% of total particles. On the other hand, small particles less than 0.5 μm in diameter accounted for 52.4% of total particles during the drying process. In contrast to the particulate matter, high concentrations of VOCs were emitted during both spraying and drying processes. Butyl acetate, xylene, toluene, and m-ethyltoluene were the most abundant VOCs emitted from the motor vehicle painting booth. Additionally, xylene, butyl acetate, toluene, and 1,2,3-trimethylbenzene were the dominant ozone precursors. Especially, xylene exhibited the highest ozone production contribution (32.5~44.4%) among 34 species of the ozone precursors. The information obtained in this study can be used to establish a suitable management strategy for air pollutants from motor vehicle painting booths.
n-Nonane, 1¸2¸4-trimethylbenzene (124-TMB), toluene, total xylene (TXYL), isopropyl alcohol (IPA), and methyl ethyl alcohol (MEK) are major volatile organic compounds (VOCs) emitted from printing industries. The absorption amount of a single VOC per unit weight of silicone oil was as follows in the order of 189.5 g/kg-silicone oil for n-nonane, 91.7 g/kg-silicone oil for 124-TMB, and 60.1 g/kg-silicone oil for TXYL. Although hydrophobic VOCs were more absorbed in silicone oil than hydrophilic VOCs such as IPA and MEK, IPA and MEK, which had log Kow values of 1 or less, also were absorbed more than 26.0 g/kg-silicone oil. In two and three mixed VOCs of n-nonane, 124-TMB, and toluene, the absorption amount of each in silicon oil was less than that of single a VOC. The total absorption amount of two mixed VOCs ranged from 47.9 g to 138.7 g/kg-silicone oil, and the total absorption amount of three mixed VOCs was 65.8 g/kg-silicone oil. These results suggest that silicone oil is a promising pretreatment solution capable of absorbing high concentrations of VOCs that are intermittently emitted from printing industries. The absorption information of VOCs obtained in this study can be used as the design parameters of a damping device for the pretreatment of VOCs.
The concentrations of odor and volatile organic compound (VOC)-inducing substances were measured using selected ion flow tube mass spectrometers (SIFT-MS). SIFT-MS can continuously measure the concentration of odor-causing substances and VOCs in real time without pre-treatment steps. Measurements were conducted during the day and at night at 10 spots in the chemical block of the Sihwa industrial complex. Similar measurement results were observed in the daytime and nighttime for materials except methyl ethyl ketone with high concentrations. A high concentration of hydrogen sulfide was also measured at night. It is expected that an amount of emissions of VOCs and odor-causing substances under the absence of inspection can be traced if measured at other industrial complexes in vulnerable times.
Fibrous adsorbents, such as activated carbon fibers (ACF) have acknowledged advantages of rapid adsorption rate and ease of modification compared with granular and powdered adsorbents. Based on the surface modification of lyocell-based ACF, we observed different surface characteristics of ACF samples with variation in the mixing ratio and impregnation time of H3PO4, NaCl, and KMnO4 solution. For an engineering application, we also explored the adsorption characteristics of thusproduced ACF samples onto volatile organic compounds (VOCs). Isothermal adsorption experiments were performed using toluene and benzene as adsorbates. Results indicate that both physical and chemical surface properties have an effect on the adsorption of volatile organic compounds (VOCs).
We analyzed volatile organic compounds (VOCs) of petroleum-based laundry solvents in closed systems by static headspace analysis and investigated the emission characteristics of odorous compounds emitted from organic solvents in the small-scale dry cleaning process. The compounds containing eight to eleven carbon atoms were analyzed to account for 96.92% of the total peak area in a GC-MS chromatogram. It was found that the compounds with ten carbon atoms showed the largest proportion. In the small-scale dry cleaning process (3 kg of laundry and 40 min of drying time), a total of 36 VOCs was quantified, and the odor contribution of these compounds was evaluated. The sum of the odor quotient (SOQ) was analyzed up to 151±163 in the first 12 min of operation. The main odor-causing compounds were acrolein, ethylbenzene, hexane, acetone, and decane, and their odor contributions were 32.28%, 13.47%, 10.52%, 10.20%, and 8.08%, respectively.