왕피천 수계 내 저서성 대형무척추동물의 군집구조 분석을 위해 총 5개 지점에서 2023년 총 4회(4월, 6월, 8월 11월) 조사를 실시하였다. 조사기간 중 저서성 대형무척추동물은 총 5문 7강 17목 77과 156종 17,179.1개체/㎡가 채집되었다. 수환경 변화에 민감한 E.P.T. 분류군은 전체 156종 중 91종이 출현하여, 전체 출현종의 58.3%를 차지 하였다. 섭식기능군(FFGs) 분석결과, 종 출현 양상은 육식성 포식자(Predator: P)가 51종(32.69%)으로, 개체 출현 양상은 주워먹는 무리(Gathering-collector: GC)가 6,867.2개체/㎡(39.97%)로 높은 비율로 출현하였다. 서식기능 군(FHGs) 분석결과, 붙는 무리(Clinger: CL)가 70종(44.87%), 12,720.6개체/㎡(74.04%)로 가장 높은 비율로 출현 하였다. 군집지수 분석결과, 우점도지수(DI) 0.43, 다양도지수(H′) 3.51, 풍부도지수(R1) 4.59 균등도지수(J′) 0.77 로 나타났다. 생물학적 수질 판정 지수(BMI) 분석결과, 평균 92.36(±0.83)으로 모든 지점에서 “매우 좋음”으로 판정되었다.

KORAD (Korea Radioactive Waste Agency, http://www.korad.or.kr) has stored slightly contaminated ascon (asphalt coated concrete mixture) that was introduced to Gyeongju repository about a decade ago waiting for a final disposal. It is believed to be mainly contaminated by radioisotope 137Cs due to impurities introduced from the outside during the ascon manufacturing process. We studied characteristics of the radioactive waste to see whether this material would be proper enough to be disposed in Gyeongju LILW repository or be other ways to reduce the disposal volume including self-disposal before its final disposal otherwise. KORAD looked into the properness of characteristics of ascon in terms of WAC (Waste Acceptance Criteria) documented by KORAD that includes general chemical and physical properties of asphalt, density, size of grains, content of organic material and possibility of existence of chelate materials that qualitatively limited to be disposed by the criteria. And other associated characteristics such as gas generation and bio degradation were also investigated. Based on the data obtained from the study, we proposed various plausible solutions in associated with operational and disposal safety and economic view points. This study will be used for KORAD’s decision on how to control and safely dispose the spent ascon within a reasonable time period. And also those experiences may be applied for other LILW issues that require treatment or conditioning of radioactive wastes in the future.

It has been investigated on the management of Strontium-90 in KAERI. It is needed to separate the solute from the salt solution for the recovery of strontium after the chlorination of the strontium oxide in molten salt. A vacuum distillation technology was used for the separation of strontium from the molten salt in our previous study. Strontium chloride was successfully carbonated by reactive distillation of SrCl2 – K2CO3 – LiCl – KCl system. In this study, it was tried to develop another route to recover strontium from the salt solution by a solid-solid reaction for avoiding the entrainment of product and the salt-K2CO3 reaction. Reactive distillation experiments were carried out for SrCl2 - K2CO3 – LiCl – KCl system. The carbonation temperature and pressure were 520°C and 0.8 bar. After the carbonation reaction, the temperature was elevated to 820°C to remove KCl from the reaction product. SrCO3 and KCl peaks were found in the XRD analysis of the residual product. It could be concluded that SrCl2 can be successfully carbonated after salt removal by the solid-solid reaction.

Understanding the dispersion of xenon isotopes following a nuclear test is critical for global security and falls within the remit of both the Comprehensive Nuclear-Test-Ban Treaty (CTBT) and the International Noble Gas Experiment (INGE). This paper aims to show if it is possible to discriminate the source of xenon releases based on the atmospheric dispersion of xenon isotopes using HYSPLIT. Using ORIGEN and SERPENT simulations, four released scenarios are defined with four different fractionation times (i.e., 1 hour, 1 day, 10 days, and 30 days) after a 1kt TNT equivalent 235U explosion event. These time-delayed release scenarios were selected to certify the possibility of mis-determining xenon release source. We use the Lagrangian dispersion model for atmospheric dispersion to predict the concentration distribution of xenon isotopes under each scenario. The model allows us to better understand how these isotopes would distribute over time and space, offering valuable data for real-world detection efforts. To our knowledge, there have been no researches on the analysis of xenon isotopic ratios considering atmospheric dispersion. In this work, we focused on the atmospheric dispersion using HYSPLIT to characterize the xenon isotopic ratios from nuclear tests. In addition, we compared the xenon isotopic ratios obtained from the atmospheric dispersion with those from ORIGEN calculations, which would be helpful to discriminate the source of the xenon releases.

It has been investigated on the management of the nuclides in KAERI. Strontium-90 is a high heatgenerating nuclide in spent nuclear fuel. It is needed to separate the salt from the salt solution for the recovery of strontium after the chlorination of the strontium oxide in molten salt. A vacuum distillation technology was used for the separation of strontium from the molten salt. It was investigated on operating conditions of reactive distillation process for the recovery of the strontium from the salt solution. At a reduced pressure, considerable amount of the carbonation agents such as K2CO3 and Li2CO3 were reduced during heating in the distiller due to the thermal decomposition. Therefore, the two step process was proposed, which is composed of a reaction step at an atmospheric pressure and a salt distillation step at a reduced pressure. In the reaction step, the condition of low temperature and high pressure is suitable to suppress the decomposition of the carbonation agent. In the salt distillation step, reduced pressure is preferable at a suitable temperature depending on the evaporation rate of the salt.

It has been studied on the disposal area reduction for the used nuclear fuel by the management of high decay-heat nuclides, long-lived nuclides, and highly mobile nuclides. It was investigated on the management of the nuclides in KAERI. Strontium-90 is a high heat-generating nuclide in spent nuclear fuel. It is needed to separate the salt from the salt solution for the recovery of strontium after the chlorination of the strontium oxide in molten salt. Vacuum distillation was used for the separation of strontium from the molten salt. Potassium carbonate was chosen as a reactive distillation reagent for SrCl2 – LiCl – KCl system by the thermodynamic calculation. Reactive distillation experiments were carried out. The residual was mainly SrCO3 in the XRD analysis. It could be concluded that K2CO3 could be one of the suitable reagents for the reactive distillation. The salt in the long–lived nuclide powders should be removed to prepare the block for disposal. Experiments were carried out using W powders (surrogate) and U3O8 powders to develop a process for the removal of the residual salt from UOx powders. The salts were successfully removed from the W and U3O8 powders by distillation.

Sustainable capacity building of the rice value chain in Africa is essential in achieving the rice self-sufficiency and poverty alleviation. The breeding capacity enhancement has also been at the heart of AfricaRice’s mandate. Therefore, the Korea-Africa Food and Agriculture Cooperation Initiative (KAFACI) has concentrated breeding capacity enhancement for young breeders or breeding technicians of national research institutes in the KAFACI member countries. Four-month trainings have been conducted at the Regional Training Center located in Saint Louis, Senegal. The actual practice training is as follows; First is to learn practical skills and techniques of key aspects of rice breeding which are field preparation and layout, sowing, transplanting, fertilizer application, weed control, water management, hybridization/crossing, selection, yield and yield components determination, and rice palatability testing. Second is to learn some theoretical aspects of plant breeding through lectures including basic principles of breeding, evaluation for biotic and abiotic stresses, and statistical analysis. Third is to learn about the accurate use of field and lab equipment for rice breeding. Forth is to learn about proper scientific reporting and presentation. The courses were organized twice per year following two rice cultivation seasons in Senegal. From 2019, a total of 24 trainees participated in the 4 month courses. We believe they have acquired the basic knowledge and skills to implement rice breeding activities indpendently in their countries.

The Korea-Africa Food and Agriculture Cooperation Initiative (KAFACI) has been cooperating with AfricaRice since 2014 for the eradication of hunger and poverty in Africa through sustainable agriculture and its industrialization. At first, rice breeding activities for staple food production started with KAFACI member countries by sharing high-yielding Tongil-type rice breeding lines and varieties. The Africa Rice Development Partnership project entitled “Enhancement of high-yielding rice germplasm and breeding capacity of rice producing countries in Africa” is implemented for the period from 2016 to 2025 with three phases. The actual rice breeding activities have been conducted by applying anther culture haploid breeding technology in the laboratory and field of AfricaRice Saint-Louis center. The 1,547 elite lines selected through participatory variety selection were distributed to 21 national breeders of KAFACI member countries. These lines derived from the 1,181 cross combination and 34,616 breeding lines on Korea and AfricaRice germplasm crossed. Among them 11 new Tongil-type rice varieties have been selected and registered in the national variety catalogue of Senegal, Mali, Rwanda, Malawi, and Tanzania.

1970년대 이후 게임시장 규모의 폭발적 성장과 함께 하드웨어의 발전을 바탕으로 온라인 게임의 성장을 비 롯하여 게임 규모는 지속적으로 확장하고 있다. 대규모 자본과 인력이 투입된 이른바 AAA게임은 게임의 시장규모를 증가시킨 순기능 이외에 게임플레이의 획일화를 가져온 역기능으로도 작용하게 되었다. 이러한 시장의 반대측면에서 소규모 또는 1인 개발자들에 의해 개발되는 인디게임이 차츰 주목받고 성장하고 있 는 추세에 있다. 특히 ‘마인크래프트’의 성공 이후에 인디게임 업계로 진입하는 소규모 게임 개발자와 1인 게임 개발자들의 양도 동반 증가하였으며, 이들은 AAA게임이 가지지 못한 독특한 아이디어와 디자인 요소 를 활용하고, 크라우드 펀딩 등의 방법을 통해 자금을 조달하는 제작 형태를 띄고 있다. 인디게임은 2022년 현재 게임 플랫폼 ‘스팀’에 등록된 게임수가 40043개에 이를 정도로 지속적인 시장 확대를 이루고 있으나 최근, 스폰서와 대규모 투자를 바탕으로 한 인디게임 개발의 추세에 힘입어 소규모 또는 1인 인디게임 개 발자들의 경쟁력은 낮아지고 있다. 본 연구에서는 2020년부터 2022년까지 ‘인디게임‘ 키워드를 바탕으로 빅 데이터 분석방법을 통하여 인디게임 산업의 이슈를 추출하고 이슈와 관련한 게임의 현황과 향후 인디게임 방향성을 밝혀보고자 하였다. 연구의 결과로 2020년의 인디게임 플랫폼의 보급과 함께 시장이 확장되는 것 을 알 수 있으며, 2021년은 인디게임 보급을 뒷받침 할 수 있는 지원정책이 확산되는 현상을 파악할 수 있 었다. 2022년은 다양한 해외 플랫폼을 바탕으로 지원정책에 힘입어 지속적으로 제작되고 있으며 해외진출 을 시도함과 동시에 인디게임 산업의 활성화를 위한 육성정책이 이루어지고 있음을 알 수 있다.

Strontium-90 is a high heat-generating nuclide in spent nuclear fuel. The removal of the nuclide separation is indispensable to reduce the burden of storage and disposal of high-level radioactive waste. Korea Atomic Energy Research Institute has developed the molten salt immersion technique to separate the strontium by the chlorination of the strontium oxide in molten salt. It is needed to separate the salt for the recovery of strontium from the salt solution after the chlorination reaction. In this study, it was investigated on the recovery of the strontium from the salt. Vacuum distillation was used for the separation of strontium from the molten salt. The vapor pressures of the candidate salts were calculated by HSC chemistry and the apparent evaporation rates (AER) were measured at 830°C to evaluate the salts for strontium recovery. The candidate salts were LiCl, KCl, MgCl2, NaCl and CaCl2. The AERs of MgCl2 and NaCl were 1.9 and 1.3 g/cm2-h, respectively. Those two salts can be separated from the strontium compound even though the AER values are much lower than those of LiCl-KCl (~ 8 g/cm2-h). CaCl2 salt was rarely evaporated (AER < 0.03 g/cm2-h) and it is not suitable to use as a strontium recovery salt. Therefore, MgCl2, NaCl, LiCl and KCl can be regarded as candidates for a strontium recovery salt.

PURPOSES : The objective of this study is to determine the characteristics of nitrogen oxide (NOx) concentration in an exclusive median bus lane station. The hourly variations of NOx concentration and the effect of traffic volume on NOx concentration were analyzed using NOx measurement data and the number of vehicles at the station. METHODS : Data were collected using the chemiluminescence method for NOx concentration. Atmospheric information and traffic volume of buses were collected from the Korea Meteorological Administration and Bus Information System, respectively. RESULTS : As a result, the NO2 concentration in the test section was found to have a strong correlation with those in the atmospheric measurement station located near the test-bed. In addition, the average NOx concentrations in the test section were significantly higher than those of the other monitoring stations due to bus emissions. The average NOx concentration in the exit section was higher than that in the entry section owing to the vehicle’s frequent stops and fuel consumption due to acceleration. During the measurement period, the average NOx concentration was measured as approximately 33 % higher in the exit section than in the entry section. In addition, the NOx concentration at the bus station was found to increase as the bus dwell time increased, rather than the number of bus passages. CONCLUSIONS : This study provides clear characteristics of the NOx correlations with traffic information in an exclusive median bus lane station. It was shown that the NOx concentration at the bus station increased as the number of passes and bus dwell time increased. According to the coefficient of determination, the dwell time is more closely correlated to the NOx concentration at the bus station than the number of bus passes, indicating that it is a better parameter for predicting NOx concentration at bus stations.

The pitch-based activated carbons were prepared with KOH/KMnO4 as a multiple function activation agent to increase the specific capacitance of a supercapacitor electrode active material. And the porous structure and electrochemical properties of activated carbon were analyzed on varying amounts of KMnO4. KMnO4 was decomposed into K2O, MnO, and O2 at the activation temperature of KOH, and MnO was introduced to activated carbon. K2O/ O2 reacts with a surrounding pitch to generate micropores and forms a pathway that exposes MnO to the outside. It also affects to the specific surface area of activated carbon like KOH chemical activation. The enhanced specific surface area and introduced MnO in activated carbon led to a 28.9% increase in specific capacitance.

본 연구는 관상가치가 뛰어난 산꼬리풀의 분화 재배법을 확립하고자 차광, 기비, 추비, 왜화제 및 적심처리를 각각 달리하여 수행하였다. 연구의 결과 차광 시 산꼬리풀의 생육이 감소 하였으며, 차광률이 증가할수록 크게 억제되었다. 기비 처리는 초장, 절간장, 경직경 및 엽수를 유의적으로 증가하였으나, Hyponex를 이용한 추비 처리는 무처리와 비교했을 때 생육증가에 큰 영향을 미치지 않았다. 왜화제 처리시 diniconazole은 농도에 관계없이 왜화효과가 나타났으며, 농도가 증가할수록 크게 억제되었다. Daminozide는 저농도 처리시 무처리와 비교하여 큰 차이가 없었으나, 2000mg·L-1 농도로 처리하였을 때 왜화효과가 나타났으며, 개화율은 diniconazole 저농도에서 가장 낮은 결과를 보였다. 한편 적심 처리에 따른 유의적인 생육 차이는 확인되지 않았다.

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).

본 연구는 설문을 통해 ‘스마트 그린오피스(Smart Green Office)’에 대해 대중의 인식과 선호도를 알아보고, 활성화를 위한 기반을 마련하고자 수행하였다. 총 195명을 대상으로 설문조사를 진행하였으며, 실내식물에 대한 인식과 ‘스마트 그린오피스’의 인식 및 선호도에 대하여 조사하였다. 설문조사 결과, 설문에 참여한 대부분의 응답자들은 실내식물을 선호하며, 접근성과 필요성에 대해 긍정적으로 답변한 것으로 조사되었다. 응답자들이 실내식물을 통해 ‘공기 질 향상(52.0%)’ 및 ‘스트레스 해소(34.0%)’등 긍정적인 효과를 경험한 적이 있기 때문에 실내식물의 기능을 인지하고 필요성을 크게 인식하는 것으로 판단된다. ‘스마트 그린오피스’의 인지도에 대해 조사한 결과, 알거나 들어본 경험이 있는 사람은 15.4%로 적었으나 개념을 설명한 후, 필요성을 느끼고 설치를 원하는 응답자들 은 90% 이상으로 조사되었다. 응답자들은 ‘공기정화(83.6%)’ 기능 때문에 ‘스마트 그린오피스’ 도입 이 필요하다고 하였으며, 오피스 내 도입 시‘공기정화 식물(70.8%)’로 이루어진 벽면형태(41.0%)’를 선호하는 것으로 조사되었다. 또한, ‘비용 (45.6%)’과 ‘유지 관리(28.2%)’등의 문제가 ‘스마트 그린오피스’ 도입 시 고려하는 점으로 조사되었으며, 설치 시 비용은 ‘200만원 이하(56.4%)’와 ‘200~450 만원(38.5%)’을 선호하는 것으로 조사되었다. ‘스마트 그린오피스’의 인식 및 선호도와 더불어 비활성화에 대한 원인을 조사한 결과, ‘낮은 인지도’ 및 ‘스 마트 그린오피스’의 개념을 인지하지 못한 ‘불필요’가 각각 25.1%와 42.6%로 조사되었으며, ‘적극적인 마케팅 및 홍보 (46.2%)와 ‘실내식물에 대한 관심도 향상(38.0%)’이 이를 해결하기 위한 방법이라고 응답하였다. 따라서, ‘스마트 그린오피스’의 올바른 의미를 알리고, 공기정화 식물로 이루어진 벽면형태의 디자인 개발 및 모델 제시와 같이 ‘스마트 그린오피스’가 활성화될 수 있도록 홍보를 통한 다양한 정보 제공 등 여러 방안 모색이 필요할 것으로 판단된다.

Manufactured part based on the drawing must be inspected for quality control. If no restraint note is specified on the drawing, the part should be inspected without any clamping(restraining). However if there is a restraint note, the part is non-rigid part. When inspecting non-rigid parts, there are two areas that need special attention: proper restraining of the part and determining which tolerances are checked in the retrained state. Mounting and restraining the part on the appropriate datum features is the first area. When retraining the part, the only forces that should be used are the ones described in the restraint note. The sequence for applying the restraining force specified on the drawing should be followed. The location, direction and amount of force should be in accordance with the restraint note. Once the part is restrained, the tolerances can be verified. When inspecting non-rigid part, the inspector needs to determine which dimensions and tolerances are to be checked in the retrained state. Careful reading of the restraint note will indicate if all or certain tolerances are to be checked in the restrained condition. Each feature control frame should be examined for the use of free state modifier. If a free state modifier is specified, the geometric control should be inspected with the part in the free state. When inspecting a non-rigid part on a coordinate measuring machine(CMM), fixture and clamp should be used to locate and clamp the part. The fixture will establish the proper part restraint conditions and datums. If a fixture is not used when inspecting non-rigid parts, it will be difficult or impossible repeatable measurements.