• Korean Journal of Ecology and Environment
• /
• v.54 no.4
• /
• pp.280-290
• /
• 2021

The present study investigated species richness and phytoplankton community structure in lakes in the Geum River Basin during autumn and spring seasons. Surveys were conducted between September and November 2019, and between April and May 2020, which corresponded to the autumn and spring seasons, respectively, to explore the distribution characteristics of the species. A total of 49 species of phytoplankton belonging to 31 genera and seven classes were identified in Cho Pyeong-ji, 51 species belonging to 29 genera and six classes were identified in Song Ak-ji, 49 species belonging to 32 genera and seven classes were identified in Cheong Cheon-ji, 82 species belonging to 45 genera and six classes were identified in Ye Dangji, and 70 species belonging to 40 genera and six classes were identified in Ganwol Lake. A total of 43 species belonging to 74 genera and seven classes were identified. The ranges of phytoplankton standing crop were as follows: 223~3533 cells mL^-1 in Cho Pyeong-ji, 881~176018 cells mL^-1 in Song Ak-ji, 402~6139 cells mL^-1 in Cheong Cheon-ji, 262~10460 cells mL^-1 in Ye Dang-ji, and 20413~330695 cells mL^-1 in Ganwol Lake. Phytoplankton diversity in Cho Pyeong-ji, Song Ak-ji, Cheong Cheon-ji, Ye Dang-ji, and Ganwol Lake were 1.10~2.60, 0.56~2.03, 0.21~2.03, 0.65~2.57, and 0.44~1.12, respectively. Phytoplankton species richness in Cho Pyeong-ji, Song Ak-ji, Cheong Cheon-ji, Ye Dang-ji, and Ganwol Lake were 1.91~4.99, 1.82~3.26, 1.26~4.17, 2.07~5.37, and 1.90~2.43, respectively. Phytoplankton evenness indices in Cho Pyeong-ji, Song Ak-ji, Cheong Cheon-ji, Ye Dang-ji, and Ganwol Lake were 0.38~0.78, 0.18~0.69, 0.08~0.71, 0.22~0.72, and 0.14~0.38, respectively. Phytoplankton dominance indices in Cho Pyeong-ji, Song Ak-ji, Cheong Cheon-ji, Ye Dang-ji, and Ganwol Lake were 0.40~0.83, 0.55~0.96, 0.44~0.99, 0.42~0.93, and 0.89~0.97, respectively.

• Journal of Ginseng Culture
• /
• v.4
• /
• pp.128-141
• /
• 2022

Baengnyeongdo Island, which belongs to Ongjin-gun, Incheon, is an island in the northernmost part of the West Sea in South Korea. Baengnyeong Island is the 15th largest island in Korea and covers an area of 51 km². The Korea Ginseng Corporation (KGC) investigated the possibility of growing ginseng on Baengnyeong Island in 1996. In 1997, thanks to the support of cultivation costs from Ongjin-gun, the first ginseng seedbed was built on Baengnyeong Island. In 1999, the seedlings were transplanted to a permanent field under a contract with KGC. In 2003, the first six-year-old ginseng harvest was performed, and KGC purchased all production according to the contract. Since then, KGC has signed on to grow ginseng until 2012 and purchased six-year-old ginseng until the fall of 2016. Since 2014, the GimpoPaju Ginseng Agricultural Cooperative Association has signed a ginseng production contract. According to a survey of nine 6-year-old ginseng fields (total 5,961 units) on Baengnyeong Island, the top five with good growth had a survival rate of 42.6 to 68%, and the bottom four with poor growth had an extremely low survival rate of 11.1 to 21.3%. The four fields with low survival rates were where hot peppers were planted before ginseng cultivation. It is believed that the excess nitrogen remaining in the soil due to the treatment of compost or manure during pepper cultivation causes ginseng roots to rot. The average incidence of Alternaria blight was 8.6%. Six six-year-old ginseng gardens were low at 1.1 to 4.7%, while the other three were high at 16.7 to 20.9%. It is assumed that the reason for the low survival rate and high incidence of Alternaria blight is a rain-leaking shield. Farmers used rain-leaking shields because the precipitation on Baengnyeong Island was smaller than on land. One field showed 3% of leaves with yellowish brown spots, a symptom of physiological disturbance of the leaf, which is presumed to be due to the excessive presence of iron in the soil. To increase the production of ginseng on Baengnyeong Island, it is necessary to develop a suitable ginseng cultivation method for the island, such as strengthening the field management based on the results of a scientific study of soil, using rain-resistant shading, and installing drip irrigation facilities. I hope that ginseng will become a new driving force for the development of Baengnyeong Island, allowing ginseng products and food to thrive in the beautiful natural environment of the island.

• Korean Journal of Plant Resources
• /
• v.35 no.5
• /
• pp.652-658
• /
• 2022

This study was conducted to induce somatic embryogenic callus (SEC) derived from petals in rose. The petal explants of 3 cultivars ('Ice Wing', 'Orange Eye' and 'Pink Beauty') with different flower colors were placed on three types media (MS, SH and WPM) supplemented with 11 mg/L 2,4-D, respectively, and then cultured in the dark for 47 days. Calluses were formed at explants of all three cultivars. Also, 'Ice Wing', which were cultured in the SH as the basal medium, showed the highest callus formation rate. However, somatic embryos were generated from only petal-derived callus of 'Ice Wing', which were induced on the WPM as the basal medium, transferred it to SH basal medium supplemented with 3 mg/L 2,4-D, and 300 mg/L L-proline, and cultured for 5 weeks. The SEC has been proliferated every four weeks at the subculture interval. In addition, as a results of making a comparison of expression of RhSERK3 and RhSERK4, which is used as signal for generation of somatic embryo from callus in rose, between the SEC and petal-derived callus from 'Ice Wing' by RT-qPCR, the former showed 10 times higher RhSERK3 expression and 700 times higher RhSERK4 expression than the latter.

• Korean Chemical Engineering Research
• /
• v.60 no.4
• /
• pp.606-612
• /
• 2022

Relatively high indoor CO₂ concentration (>1,000 ppm) has a negative impact on human health. In this work, indoor CO₂ adsorbent was developed by impregnating KOH or K₂CO₃ on commercial activated carbon, named as KOH/AC and K₂CO₃/AC. Commercial activated carbon (AC) showed relatively high BET surface area (929 m²/g) whereas KOH/AC and K₂CO₃/AC presented lower BET surface area of 13.6 m²/g and 289 m²/g. Two experimental methods of TGA (2,000 ppmCO₂, weight basis) and chamber test (initial concentration: 2,000 ppmCO₂, CO₂ IR analyzer) were used to investigate the adsorption capacity. KOH/AC and K₂CO₃/AC exhibited similar adsorption capacities (145~150 mg_CO2/g), higher than K₂CO₃/Al+Si supports adsorbent (84.1 mg_CO2/g_sample). Similarly, chamber test also showed similar trend. Both KOH/AC and K₂CO₃/AC represented higher adsorption capacities (KOH/AC: 93.5 mg_CO2/g K₂CO₃/AC: 94.5 mg_CO2/g_sample) K₂CO₃/Al+Si supports. This is due to the KOH or K₂CO₃ impregnation increased alkaline active sites (chemical adsorption), which is beneficial for CO₂ adsorption. In addition, the regeneration test results showed both K-based adsorbents pose a good regeneration and reusability. Finally, the current study suggested that both KOH/AC and K₂CO₃/AC have a great potential to be used as CO₂ adsorbent for indoor CO₂ adsorption.

• Journal of Appropriate Technology
• /
• v.7 no.2
• /
• pp.162-171
• /
• 2021

The Korean government proposed the K-SDGs in 2019 to promote the UN SDGs, but the role and tasks of science and technology, an important means of implementing the SDGs, have not been materialized. Accordingly, the role of science and technology ODA for the SDGs was established through the Ministry of Science and ICT's policy research project 'Science and Technology ODA Promotion Roadmap for Spreading the New Southern Policy and Realizing the 2030 SDGs'. In addition, goals, strategies, and core tasks for the next 10 years were derived in 10 fields such as water, climate change, energy, and ICT. In this paper, we analyze 30 key tasks of the ODA promotion roadmap for science and technology for the realization of SDGs, and propose mid- and short-term tasks and implementation plans for effective roadmap promotion. Among the key tasks in each field, four common elements were derived: ICT/smartization, a global problem-solving center, cooperation/communication platform, and business model/startup support platform/living lab that can create and integrate roadmap implementation conditions. In addition, the four mid- and short-term tasks, 1) Establishment of science and technology ODA network, 2) Establishment of living lab business platform linked to start-up support business, 3) Local smartization of recipient countries, and 4) Expand and secure sustainability of global problem-solving centers, were set in relation to the implementation of the detailed roadmap. For the derived mid- and short-term tasks, detailed implementation plans based on the ICTization of global problem-solving centers were presented. The implementation of the mid- and short-term tasks presented in this paper can contribute to the more effective achievement of the science and technology ODA roadmap, and it is expected that Korea's implementation of SDGs will also achieve high performance.

• Journal of the Microelectronics and Packaging Society
• /
• v.28 no.4
• /
• pp.11-18
• /
• 2021

A novel microwave dielectric composite material for ultra-low temperature co-fired ceramics (ULTCC) with (1-x)BaWO₄-xBaV₂O₆ (x=0.54~0.85) composition was prepared by firing a mixture of BaWO₄ and BaV₂O₆. Shrinkage tests showed that the ceramic composite begins to densify at a temperature as low as 550℃ and can be sintered at 650℃ with 98% of relative density under the influence of BaV₂O₆. X-ray diffraction analysis showed that BaWO₄ and BaV₂O₆ coexisted and no secondary phase was detected in the sintered bodies, implying good chemical compatibility between the two phases. Near-zero temperature coefficients of the resonant frequency (𝛕_f) could be achieved by controlling the relative content of the two phases, due to their positive and negative 𝛕_f values, respectively. With increasing BaV₂O₆ (x from 0.53 to 0.85), the 𝛕_f value of the composites increased from -7.54 to 14.49 ppm/℃, ε_r increased from 10.08 to 11.17 and the quality factor (Q×f value) decreased from 47,661 to 37,131 GHz. The best microwave dielectric properties were obtained for x=0.6 samples with ε_r=10.4, Q×f=44,090 GHz, and 𝛕_f=-2.38 ppm/℃. Chemical compatibility experiments showed the developed composites are compatible with aluminum electrode during co-firing process.

• Journal of Korea Water Resources Association
• /
• v.55 no.8
• /
• pp.623-634
• /
• 2022

Due to river maintenance projects such as the creation of hydrophilic areas around rivers and the Four Rivers Project, the flow characteristics of rivers are continuously changing, and the risk of water quality accidents due to the inflow of various pollutants is increasing. In the event of a water quality accident, it is necessary to minimize the effect on the downstream side by predicting the concentration and arrival time of pollutants in consideration of the flow characteristics of the river. In order to track the behavior of these pollutants, it is necessary to calculate the diffusion coefficient and dispersion coefficient for each section of the river. Among them, the dispersion coefficient is used to analyze the diffusion range of soluble pollutants. Existing experimental research cases for tracking the behavior of pollutants require a lot of manpower and cost, and it is difficult to obtain spatially high-resolution data due to limited equipment operation. Recently, research on tracking contaminants using RGB drones has been conducted, but RGB images also have a limitation in that spectral information is limitedly collected. In this study, to supplement the limitations of existing studies, a hyperspectral sensor was mounted on a remote sensing platform using a drone to collect temporally and spatially higher-resolution data than conventional contact measurement. Using the collected spatio-temporal hyperspectral images, the tracer concentration was calculated and the transverse dispersion coefficient was derived. It is expected that by overcoming the limitations of the drone platform through future research and upgrading the dispersion coefficient calculation technology, it will be possible to detect various pollutants leaking into the water system, and to detect changes in various water quality items and river factors.

• Journal of The Korean Association For Science Education
• /
• v.42 no.1
• /
• pp.77-96
• /
• 2022

This study investigated how collaborative reflection between novice secondary science teachers promoted the development of teaching professionalism. We intentionally selected research participants who shared sufficient rapport. Data were collected by videotaping the classes taught by participants, pre-talk, post-interviews and nine collaborative reflection processes. All data were transcribed and analyzed. Results indicated that all three teachers showed changes in teaching practice. Minyoung's practice involved a teacher-led lecture, but through collaborative reflection, she could create a learning environment to enhance students' power and ownership in her class. Emphasizing academic rigor, Soyoung used to teach content outside the scope of the curriculum, but through collaborative reflection, she became more considerate of students' understanding. Finally, in Jiyeon's classes inquiry activities and theoretical explanations were separated from each other. However, she repeated her efforts to improve her class after collaborative reflection, allowing students to construct explanations through activities. In this study, three factors that promoted the development of teachers' pedagogical content knowledge through collaborative reflection were identified. First, the different teaching orientations of the three teachers who participated in this study, promoted sharing of opinions through collaborative reflection. Second, reflection based on teaching practice enabled practical feedback on the class, which enhanced the development of teachers' pedagogical content knowledge. Third, the equal status and formation of rapport between the three teachers created an environment for productive reflection. These results suggest that future teacher education programs should target communities that can promote collaborative reflection based on teachers' teaching practice.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
• /
• v.16 no.6
• /
• pp.197-211
• /
• 2021

In the service industry the types are diversifying and the scale of service companies is greatly improving. Such a phenomenon is caused by economic growth and technological development diversifying consumer needs creating demand for new services maturing the service industry and intensifying competition among companies in the form of global competition. It can be said that this is because it is necessary to improve competitiveness by utilizing the economy of scale. Research is needed on the impact of entrepreneurship on various outcome variables in order for service organization managers to respond quickly to diverse and rapidly changing environments and achieve organizational outcomes and corporate goals of management outcomes. The purpose of this study was to empirically analyze the relationship in which the entrepreneurial spirit of a manager influences the relationship between customer orientation, which is an organizational result, customer satisfaction, and financial result, which is a management result. In order to verify such research, the questionnaire was composed of one business owner questionnaire, two employee questionnaires, and two customer questionnaires. The questionnaire was distributed to a total of 400 companies, and the questionnaires of 340 companies were collected. Of these, 303 companies, excluding the questionnaires of 37 companies with many dishonest or missing values, were used for hypothesis testing. The results of this study can be summarized as follows. First, entrepreneurship had a positive (+) effect on customer orientation, supporting the hypothesis. Second, customer orientation showed a positive (+) effect on customer satisfaction, supporting the hypothesis. Third, customer satisfaction showed a positive (+) effect on financial outcomes, supporting the hypothesis. Fourth, it was found that entrepreneurship influences customer satisfaction through customer orientation, and customer satisfaction affects financial outcomes. It turns out that customer orientation between entrepreneurship and customer satisfaction is completely mediated, and customer satisfaction is completely mediated by customer orientation and financial outcomes. The relationship between entrepreneurship and management improved employee behavior and attitudes, which is an individual outcome, and this change was found to improve customer satisfaction, which is an organizational outcome. It makes frequent contact with customers in the process of servicing them. Employee roles are important at service contacts and influence service purchases. Employees facing customers through service contacts act as a decisive factor in maintaining a continuous relationship with customers. Within a beauty service company, it is necessary to create a customer-oriented environment among workers. It suggests that customer-oriented companies and employees can anticipate their desires and provide products or services of superior value to achieve greater customer satisfaction and a competitive advantage. In addition, it was clarified that customer satisfaction has an aspect relationship with financial management, which is a management result. Therefore, it is suggested that the entrepreneurial spirit is an important factor for the management of a beauty service company to secure competitiveness and improve results.

• Clean Technology
• /
• v.28 no.2
• /
• pp.131-137
• /
• 2022

The semiconductor process currently emits various by-products and unused gases. Emissions containing pollutants are generally classified into categories such as organic, acid, alkali, thermal, and cabinet exhaust. They are discharged after treatment in an atmospheric prevention facility suitable for each exhaust type. The main components of organic exhaust are volatile organic compounds (VOC), which is a generic term for oxygen-containing hydrocarbons, sulfur-containing hydrocarbons, and volatile hydrocarbons, while the main components of alkali exhaust include ammonia and tetramethylammonium hydroxide. The purpose of this study was to determine the combustion characteristics and analyze the NO_X reduction rate by maintaining a direct combustion and temperature to process organic and alkaline exhaust gases simultaneously. Acetone, isopropyl alcohol (IPA), and propylene glycol methyl ether acetate (PGMEA) were used as VOCs and ammonia was used as an alkali exhaust material. Independent and VOC-ammonia mixture combustion tests were conducted for each material. The combustion tests for the VOCs confirmed that complete combustion occurred at an equivalence ratio of 1.4. In the ammonia combustion test, the NO_X concentration decreased at a lower equivalence ratio. In the co-combustion of VOC and ammonia, NO was dominant in the NO_X emission while NO₂ was detected at approximately 10 ppm. Overall, the concentration of nitrogen oxide decreased due to the activation of the oxidation reaction as the reaction temperature increased. On the other hand, the concentration of carbon dioxide increased. Flameless combustion with an electric heat source achieved successful combustion of VOC and ammonia. This technology is expected to have advantages in cost and compactness compared to existing organic and alkaline treatment systems applied separately.