In order to provide fundamental information about the floristic composition of the area along with an assessment of the environmental impact, a floristic study of the vascular plants in the Tamjin River estuary in Gangjin-gun was conducted for a total of nine days, in the period from June 2014 to September 2014. We found that the vascular plants in this region comprised 424 taxa belong to 102 families, 281 genera, 390 species, 5 subspecies, 26 varieties, and 3 forma. Five taxa of Korean endemic plants including Weigela subsessilis (Nakai) L.H.Bailey, Lespedeza maximowiczii var. tricolor (Nakai) Nakai, and Clematis trichotoma Nakai were collected. Two least concern (LC) taxa of rare plants (as designated by the Korea Forest Service) were collected: Hydrocharis dubia (Blume) Backer and Platycladus orientalis (L.) Franco. Ten the floristic regional indicator taxa from the third to the fifth grade were identified: two taxa belonged to grade IV, and eight taxa belonged to grade III. Twenty-four taxa of salt-tolerant plants, including Artemisia fukudo Makino, Carex rugulosa Kuk., and Suaeda glauca (Bunge) Bunge, as well as 44 taxa of aquatic plants, including Najas marina L., Nuphar oguraensis Miki, and Nymphoides indica (L.) Kuntze, were investigated in this region. Fifty-nine taxa of naturalized plants were recorded, among which the following six taxa were plants that caused ecosystem disturbance: Ambrosia artemisiifolia L., Humulus scandens (Lour.) Merr., Lactuca scariola L., Rumex acetosella L., Solidago altissima L., and Symphyotrichum pilosum (Willd.) G.L.Nesom.
To improve the initial strength and stability of lightweight-foamed concrete, which shows suitable sound absorption and insulation characteristics, the effect of CO2-reduced cement on the properties of the concrete was investigated. Various mixing ratios were applied by substituting a certain amount of slag and Calcium Sulfo Aluminate (CSA) in CO2-reduced Ordinary Portland Cement (OPC) and the physical properties of the samples were examined using the Korean Standard. The kiln temperatures of the CSA were 100–200°C ; these values are lower than those of OPC and can lead to energy saving. In addition, the low limestone content reduces greenhouse gas emissions by 20 %. Adding a small amount of CSA in OPC content activates Ca-Al-H2-based hydrates, and the initial compressive strength of the concrete is improved. As the CSA content increased, the thermal conductivity of the concrete decreased by up to 8% compared to plain concrete, thus indicating an improvement in its insulation. Therefore, the settlement stability was improved as the addition of CSA shortened the setting time.
The purpose of this study is to evaluate the importance of policy for the promotion of forest education and establish a basis that can be applied to it, which considers citizens’ opinions on forest education. According to the importance analysis of forest education policy, program development topped the list with 0.368 points, followed by the application of forest education experts, which scored 0.262 points. Cooperation as well as the supplementing and improvement of facilities yielded 0.238 and 0.132 points, respectively. Concerning the attention and recognition of forest education, only 8% of the respondents had low attention and 19% low or very low recognition; 75% said forest education was very important. Regarding program satisfaction, 76.5% were satisfied with the profitability of content and 77% agreed with the purpose consistency. In terms of the appropriateness of forest education, 79.2% and 81% were content with the period and method, respectively. Finally, 82.7% were satisfied with the participation program. This study aims to share basic data and promotion plans derived from the analysis of policy importance and satisfaction with forest education focused on adults. Domestic forest education is still in the early stages, led by Korea Forest Service. In the long term, local governments must participate in forest education policy positively despite limited budgets and human resources. The results of this study can be utilized as data for forest education promotion plans. If the case studies of other local governments and preference analysis by age group are followed up, they will help ensure that forest education evolves through cooperation with people and organizations in the relevant zone.
This study analyzes the effect of negative air ions on the concentration of airborne particulate matter and evaluates the expected purification efficiency of open spaces for particulate matter by investigating the amount of negative air ions generated by plants. This study establishes a negative air ion generation treatment environment, plant environment, and control environment to measure the purification efficiency of particulate matter under the conditions of each, analyzing the expected purification efficiency by designing a particulate matter purification model. Results show that the amount of generated negative air ion according to environment was negative air ion generation treatment environment > plant environment > control environment; this order also applies to the particulate matter purification efficiency. Moreover, it took 65 min for the negative ion generation treatment environment, 90 min for the plant environment, and 240 min for the control environment to reach the standard expected purification efficiency of particulate matter concentration of 960 mg/m³ for PM10. For PM2.5, with the designated maximum concentration of 700 mg/m³, it took 60 min for the negative ion generation treatment environment, 80 min for the plant environment, and more than 240 min for the control environment. Based on these results, the expected purification efficiency compared to the control environment was quadrupled in the negative ion generation treatment environment and tripled in the plant environment on average.
Water temperature is one of the most important factors of fish survival, affecting the habitat, migration route, development, and reproduction. This experiment studied the induction level of heat shock protein (HSP70) mRNA and protein in a walleye pollock (Gadus chalcogrammus) primary hepatocyte culture based on different temperatures. Hepatocytes were attached at 7.5 °C for 24 hours. Hsp70 induction levels were then measured for 48 hours at 5, 8, 11, 14, and 17 °C. The induction level was lowest at 5 °C and generally increased with temperature until 14 °C. The induction level was reduced at 17 °C, indicating that 14 °C is the highest tolerable temperature for hepatocytes. These data indicate that primary hepatocyte cell culture is under no stress at 5 and 8 °C. Temperatures greater than 11 °C induce stress, showing similar induction patterns in both mRNA and protein in hepatocytes. The results suggest that 14 °C is the maximum internal defense temperature of walleye pollock survival.
Recent economic and income growth in Korea has caused people to seek healthier and happier lives. Forests are seen as spaces that provide tourism and recreation. The Korea forest service and local governments are developing and designating recreational forests but previous studies on the subject have only covered customer satisfaction and how forests are used. As such, the current study aims to find issues with designation criteria for recreational forests used by Gwangju city in Gyeonggi province and suggest improvements to the system. Site E was deemed the most adequate in evaluations of five candidate site. The criteria used in the evaluations were problematic due to (1) a lack of differentiating power in evaluation items, (2) blanket coverage of score ranges, (3) a lack of additional points for special sites, and (4) unclear evaluation indices. Based on the identified issues, the current study suggests introducing additional points and clearly detailing evaluation indices and items to enhance the evaluation of recreational forest candidate sites.
Water and sediment qualities were investigated in the Oncheon Stream and at the Wondong bridge of the Suyoung River, during the summer rainy season, 2019. Dissolved oxygen (DO) showed the lowest levels at 4.7 and 5.0 m/L, and biogeochemical oxygen demand (BOD) showed the highest at 5.3 mg/L downstream where the tributary flows into the main river. Chemical oxygen demand (COD) increased from 2.0 to 5.9 mg/L on average as it flowed downstream, The COD/BOD ratio decreased gradually as it flowed downstream, reaching 1.0. However, COD/BOD ratio at the Wondong bridge was 5.8-22.2, indicating that easily biodegradable and non-biodegradable organic matter flows into the Oncheon Stream and Suyoung River, respectively. Total nitrogen (T-N) / total phosphorus (T-P) ratio tended to decrease from 72 to 21 as it flowed downstream, measuring 71 to 86 at the Wondong bridge. The water quality index (WQI) generally improved better than grade IV after heavy rainfalls. However, DO and T-P were the parameters that deteriorated the WQI. Ignition loss (IL), COD, T-N, and T-P of sediments had distribution of 1.44 ± 1.01%, 0.35 ± 0.16%, 43 ± 63 mg/kg, and 10.9 ± 21.9 mg/kg, respectively. These were several times lower than the annual averages of IL, T-N, and T-P in 2017 before the dredging project was conducted in the first half of 2018.
This study investigates the concentration distribution of aldehydes and volatile organic compounds (VOCs) in the archive of the National Library in Korea and evaluates the health risks to workers from hazardous chemicals. Acetaldehyde had the highest concentration among the nine species of aldehydes present in the archive and the concentration of toluene was the highest among the six species of VOCs. Most of the detected substances showed that their indoor concentrations were higher than the outdoor ones, suggesting the possibility of indoor sources of aldehydes and VOCs. The evaluation of health risks for workers based on these measurement results showed that not all substances were hazardous to the human body. However, considering the possibility of the presence of indoor sources and the potential limits of our study owing its short period, it is necessary to conduct long-term studies on the concentration distribution of indoor pollutants in the archive environment.
According to a NASA Goddard Institute for Space Studies report, temperatures have risen by approximately 1 °C so far, based on temperatures recorded in 1880. The 2003 heatwave in Europe affected approximately 35,000 people across Europe. In this study, a cooling fog, which is used in smart cities, was designed to efficiently reduce the temperature during a heatwave and its pilot test results were interpreted. A model experiment of the cooling fog was conducted using a chamber, in which nano mist spray instruments and spray nozzles were installed. The designed cooling fog chamber model showed a temperature reduction of up to 13.8 °C for artificial pavement and up to 8.0 °C for green surfaces. However, this model was limited by constant wind speed in the experiment. Moreover, if the cooling fog is used when the wind speed is more than 3m/s in the active green zone, the temperature reduction felt by humans is expected to be even greater. As a second study, the effect of cooling fog on temperature reduction was analyzed by installing a pilot test inside the Land Housing Institute (LHI). The data gathered in this research can be useful for the study of heat reduction techniques in urban areas.