대기오염물질과 온실가스 배출량을 저감 시키기 위한 배기 후처리 장치에 대한 연구는 활발히 진행 중이지만 그 중 선박용 입 자상물질/질소산화물(PM/NOx) 동시저감 장치에서는 엔진에 미치는 배압 및 필터 담체 교체에 대한 문제가 발생하고 있다. 본 연구에서는 PM/NOx를 동시저감 할 수 있는 일체형 장치의 최적 설계를 위해 장치 내부 유동과 입·출구 압력을 통한 배압의 변화를 연구하여 적절한 기준을 제시하였다. Ansys Fluent를 활용하여 디젤미립자필터(DPF) 및 선택적촉매환원법(SCR)에 다공성 매체 조건을 적용하였고 공극률은 30 %, 40 %, 50 %, 60 % 및 70 %로 설정하였다. 또한, 엔진 부하에 따른 Inlet 속도를 경계 조건으로 7.4 m/s, 10.3 m/s, 13.1 m/s 및 26.2 m/s로 적 용하여 배압에 미치는 영향을 분석하였다. CFD 분석 결과, 장치의 입구 온도 보다 입구 속도에 따른 배압의 변화율이 크고 최대 변화율은 27.4 mbar였다. 그리고 모든 경계 조건에서의 배압이 선급 기준인 68 mbar를 초과하지 않았기 때문에 1800 kW 선박에 적합한 장치로 평가 되었다.

The Ministry of Agriculture, Food and Rural Affairs introduced the Agrifood Voucher in 2020. The Agrifood Voucher is the program that provides vouchers to purchase selected food items with dietary management education. This study aimed to explore value and meaning of dietary management based on the Agrifood Voucher. First, the Supplemental Nutrition Assistance Program of the United States and the Agrifood Voucher of Korea were reviewed. Second, various terms used for describing the purpose of food assistance programs were comparatively reviewed and ‘food and nutrition security’, together with the corresponding Korean term, was proposed to be the most appropriate term for the purpose. Subsequently, the value and meaning of dietary management based on the Agrifood Voucher were presented as enhancing food and nutrition security of the vulnerable. Diverse education programs should be developed and implemented to improve the dietary management capacity of the Agrifood Voucher recipients in order to properly realize the meaning and value of dietary management based on the Agrifood Voucher in the future.

본 연구에서는 분리막을 이용하여 천일염내 미세플라스틱을 비롯한 불순물을 제거하는 분리막 공정 설계를 위한 연구이다. 천일염 염전에 적합한 분리막 재질, 공경 사이즈, 모듈을 선정하여 다양한 조건에서 실험을 진행하였다. 선정된 200 kDa, 4 kDa 한외여과막 그리고 3 kDa 나노여과막을 선정하였고, 실험은 실험실과 실제 염전에 파일롯 플랜트를 건설하 여 각각 실험하였다. 천일염내 불순물은 대부분 0.1 μm 이상의 크기를 가졌고 크기 분포는 0.1 μm에서 1 μm 사이 입자가 가장 많은 부분을 차지하였다. 그리고 성분 분석결과 불순물 내에 7종류 이상의 다양한 미세플라스틱이 검출되었다. 분리막 공정 이후 여과된 염전수 분석한 결과 미세플라스틱을 포함한 불순물이 검출되지 않았고 기존의 천일염과 분리막 여과수로 제작한 천일염의 성분 비교해본 결과 천일염 성분의 변화 없이 불순물만 효과적으로 제거됨을 확인하였다.

췌석은 만성췌장염에서 흔히 동반되는 소견으로 반복되는 복통과 췌장염의 원인이 될 수 있다. 췌석은 췌관 협착과 자주 동반되고 췌관내 박혀 있는 경우가 많아 바스켓을 이용하여 제거하기 어렵다. 체외충격파쇄석술(ESWL)로 치료하기도 하나 반복 시술이 필요하고 성공률도 높지 않았다. 최근에 개발된 SpyGlass™ DS II (Boston Scientific, Marlborough, MA, USA)는 직경이 3.5 mm로 가늘어 췌관이 확장되어 있을 때 안으로 삽입이 가능하게 되었다. 그리고 직접 췌석을 보면서 전기수압쇄석술(EHL)이나 레이저 유도 쇄석술(laser lithotripsy)를 시행하며 췌석을 제거해 볼 수 있게 되었다. 본고에서는 SpyGlass™ DS II와 EHL을 이용하여 10 mm 이상의 다발성 췌석을 제거하는 방법을 소개하고자 한다.

PURPOSES : The objective of this study was to evaluate the effectiveness of dust removal by dust removal vehicles by the measuring dust load and PM10 concentrations on the sidewalks of block pavements. METHODS : Field experiments were conducted to determine a dust removal method suitable for the sidewalk conditions, as identified through a literature review. Data collection was followed by the evaluation of the sidewalk dust load with removal vehicles and analysis of the PM10 content within a service road. Moreover, an economic analysis was conducted based on the social costs of dust reduction. RESULTS : When cleaning a sidewalk block by spraying water, the contaminants in small gaps in the block pavement could be reduced, providing a potential solution to void clogging. The dust on the surface of the sidewalk was suspended from a paved road with a high level of traffic volume. Using sidewalk dust removal vehicles with sweeping, spraying water, and inhalation reduced the dust load and PM10 contents by more than 2 and 0.07g/m2, respectively. CONCLUSIONS : According to the economic analysis of the development of dust removal vehicles for sidewalks, the cost-benefit analysis method shows an input effect of 0.4, but if the reduction amount of fine particles such as PM2.5, further experiments are necessary to address the atmospheric fine dust concentrations resulting from cleaning sidewalk block pavements.

본문은 일상적인 대화에서 화자가 청자에게 전달하는 구문 내용은 크게 ‘사건정보’ 와 ‘화자정보’로 나누어지며, 청자가 두 가지 정보를 모두 이해하면서 완전한 의사소 통이 이루어진다고 보았다. 또 ‘능원동사(조동사)’가 표현하는 의미에는 ‘화자정보’의 요소가 더 많이 함유되어 있기에, ‘사건정보’를 중심으로 한 어법기능이나 품사분류 에서 모호한 성분으로 남을 수밖에 없다고 판단하였다. 지금까지 연구에서는 ‘사건정 보’를 기반으로 한 어법관계를 통해서 능원동사의 어법기능을 파악하고자 하였고, 또 양태의미를 통한 의미영역의 분석에서도 개별 능원동사의 ‘다의성(多义性)’만을 제시 했을 뿐이다. 그래서 본문은 ‘사건정보’보다는 ‘화자정보’의 측면에서 능원동사의 의 미정보가 서로 다른 언어환경에서 어떻게 변화하는지를 고찰하고자 하였다.

Coffee is the most popular beverage in the world and various pollutants, including volatile organic compounds (VOCs), are emitted from the coffee manufacturing workplace (roasting process). In this study, we analyzed the characteristics of VOCs emissions from roasted Arabica coffee bean powder using a VOCs emission chamber with a PTR-ToF-MS. The emission test was maintained under constant temperature (20 ± 2oC) and humidity (50 ± 5%) conditions. As a result of the emission test, most of the target compounds had a high concentration in the initial period, and decreased emissions as time lapsed. Acetaldehyde showed the highest concentration and was initially 78 ppm during the test period. Acetaldehyde was followed by propionic acid at 61 ppm, propanal at 51 ppm, and isobutanal at 50 ppm. As a result of comparing the occupational exposure limits (OELs) of individual VOC emitted during the coffee roasting process, the OELs of four substances, including acetaldehyde, propionic acid, acetic acid, and pyridine were identified. Of all four substances, only pyridine exceeded the OELs, and the other compounds had levels of 10% to 30% of the OELs.

Mushroom production in Korea is concentrated on five major mushroom types. To create a new source of income for farmers, it is necessary to establish new mushroom production and marketing systems. This study was conducted to evaluate the marketability of and establish a marketing strategy for Pleurotus nebrodensis variety 'Uram'. The evaluation of distributors showed that it was necessary to cultivate mushrooms of uniform shape and size, to compensate for their low storability, and to sell them in small packages. The consumer evaluation showed that the texture of P. nebrodensis had the highest level of satisfaction for quality, but the levels of satisfaction for size and shape were low. In the consumer evaluation, as in the distributor evaluation, improvements in cultivation were found to be necessary, as the storage time is short due to a high moisture content. An evaluation of the market gave the following results regarding the marketing strategy. It was found to be necessary to consider the production of mushrooms of a uniform shape and size and sell them in small packages in the range of 150 to 300 g. The price of the mushrooms should be set using a high-end strategy for high-end sales. The mushrooms should be introduced to local food and eco-friendly stores in the early stages of production. Subsequently, if farmhouse production increases, shipments should be made to wholesale markets through a regular contract. Finally, considering that P. nebrodensis is an unfamiliar mushroom to consumers, it is necessary to promote it by increasing the accessibility of consumers through tasting events and experience groups.

This study was conducted to investigate the optimum supplementation ratio when replacing cotton seed meal with rapeseed meal for cultivating oyster mushrooms. The chemical properties among the treatments were pH 4.5~4.7, total carbon content was 46.3~46.5%, total nitrogen content was 1.6~1.7%, and carbon-nitrogen ratio was 27.0~27.8. These did not differ significantly from the control. Mycelial growth was 85.1 mm (Heuktari), and 72.8 mm (Suhan-1Ho) in medium containing 5% rapeseed meal, with no significant difference in mycelial density between cultivars. Fruiting body characteristics are as follows: In 'Heuktari', the color of the pileus was darker than control with an L value of 32.5, and pileus thickness and diameter were 3.2 mm and 27.6 mm, respectively. Stipe length and diameter were 86.0 mm and 9.1 mm, respectively. Valid stipe number per bottle (1,100 cc) was 25.9, and a yield of 189.7 g/1,100 cc was recorded in mixed medium containing 5% rapeseed meal (higher than control). In mixed medium containing 10% rapeseed meal, the yield was 184.5 g/1,100 cc (comparable to control). In 'Suhan-1Ho', supplemented with 5% rapeseed meal, pileus color was darker than control color, with an L value of 28.8. Pileus thickness was 4.5 mm. Stipe diameter was 12.3 mm (higher than control), and yield was 145.5 g/1,100 cc (comparable to control).

This study was conducted to diversify the cultivation of mushroom items and develop a competitive variety of Hypsizigus marmoreus. We focused on developing Hypsizigus marmoreus with lower bitterness, likable shape, and high yield. We have collected and tested characteristics of genetic resources from domestic and abroad since 2019. Breeding (2019), characterization (2020), productivity test (2021), and farm demonstration test (2021) have been sequentially conducted. We bred the new variety ‘Yunseul’ with unique traits. The optimal temperature for mycelial and fruit body growth were 22–25oC and 15– 18oC, respectively. It was similar to the control variety (Mangadak-2Ho) in the pileus form (hemispherical shape) and the cultivation period. However, it was thinner and longer than the control variety with the pileus diameter, thickness, stipe diameter, and length being 19.9 mm, 7.0 mm, 9.4 mm, and 86.3 mm, respectively. The effective number of fruit bodies was 47.8 in bottle cultivation, which was more than that of the control variety. The yield was 197.4 g/bottle (1,100 cc), which was 30% higher than the yield of the control variety, 151.9 g/bottle (1,100 cc). The parent and control varieties were also incubated alongside the new variety. The somatic incompatibility line was distinct. The band pattern in the mycelial DNA PCR reaction was different from that of the parent and control varieties, confirming the hybrid species.

This study was conducted to reduce the phenomenon of biased cultivation and to pursue the diversification of mushroom items. We focused on developing Sparassis latifolia varieties with a short cultivation period, stable pinheading, and a high yield. We have collected and determined the characteristics of genetic resources domestically and abroad since 2016. We bred the unique domestic variety, “Hanyeoul” and the results of this study are as follows. The optimal temperatures for mycelial growth and fruit body growth were 22~25oC and 19~21oC, respectively. The color of the pileus was pale-yellowish white, which was similar to the color of the control variety, “Neoul”. The number of days required for cultivation was 125 for bottle cultivation and 98~102 for bag cultivation, which was shorter than the number of days required for the control variety. Bottle cultivation took 39 days shorter for the new variety than the control variety. The fruiting body of the new variety was similar in size or larger than that of the control variety. The pinheading rate was more than 90% in bottle cultivation and bag cultivation, which was more stable than pinheading in the control variety. The yield was 79.1 g/bottle (1,100 cc) for bottle cultivation, which was 22.6% higher than the yield of the control variety, and 641.1~689.5 g/bag (2.6 kg) for bag cultivation, which 5.8~10.4% higher than yield of the control variety.

This study is to explore and analyze three current English teachers’ thoughts and attitudes on their TEE practices in elementary English classroom settings. Adopting a qualitative approach, data were collected through interviews, teachers’ journals, and informal communications from the three elementary school English teachers. The analysis of data revealed three main themes: 1) thoughts on effective TEE classes, 2) factors affecting TEE classes, 3) the difficulties of conducting TEE classes. The participants presented their views on effective TEE classes. They also expressed their opinion on the timing and usage of TEE. The teachers said TEE classes are influenced by teachers’ English communication ability and willingness to use English as the instructional language, students’ English proficiency and the class atmosphere. Finally, the participants said that TEE classes were difficult due to the same factors influencing TEE class effectiveness. This study has implications for the direction of TEE implementation in elementary education.

Lightweight steel is a crucial material that is being actively studied because of increased carbon emissions, tightening regulations regarding fuel efficiency, and the emergence of UAM, all of which have been recently labeled as global issues. Hence, new strategies concerning the thickness and size reduction of steel are required. In this study, we manufacture lightweight steel of the Fe-Mn-Al-C system, which has been recently studied using the DED process. By using 2.8 wt.% low-Mn lightweight steel, we attempt to solve the challenge of joining steel parts with a large amount of Mn. Among the various process variables, the laser scan power is set at 600 and 800W, and the laser scan speed is fixed at 16.67 mm/s before the experiments. Several pores and cracks are observed under both conditions, and negligibly small pores of approximately 0.5 μm are observed.

The effect of the laser beam diameter on the microstructure and hardness of 17-4 PH stainless steel manufactured via the directed energy deposition process is investigated. The pore size and area fraction are much lower using a laser beam diameter of 1.0 mm compared with those observed using a laser beam diameter of 1.8 mm. Additionally, using a relatively larger beam diameter results in pores in the form of incomplete melting. Martensite and retained austenite are observed under both conditions. A smaller width of the weld track and overlapping area are observed in the sample fabricated with a 1.0 mm beam diameter. This difference appears to be mainly caused by the energy density based on the variation in the beam diameter. The sample prepared with a beam diameter of 1.0 mm had a higher hardness near the substrate than that prepared with a 1.8 mm beam diameter, which may be influenced by the degree of melt mixing between the 17-4 PH metal powder and carbon steel substrate.

In this study, additive manufacturing of a functionally graded material (FGM) as an alternative to joining dissimilar metals is investigated using directed energy deposition (DED). FGM consists of five different layers, which are mixtures of austenitic stainless steel (type 316 L) and low-alloy steel (LAS, ferritic steel) at ratios of 100:0 (A layer), 75:25 (B layer), 50:50 (C layer), 25:75 (D layer), and 0:100 (E layer), respectively, in each deposition layer. The FGM samples are successfully fabricated without cracks or delamination using the DED method, and specimens are characterized using optical and scanning electron microscopy to monitor their microstructures. In layers C and D of the sample, the tensile strength is determined to be very high owing to the formation of ferrite and martensite structures. However, the elongation is high in layers A and B, which contain a large fraction of austenite.

The plastic deformation behavior of additively manufactured anisotropic structures are analyzed using the finite element method (FEM). Hill’s quadratic anisotropic yield function is used, and a modified return-mapping method based on dual potential is presented. The plane stress biaxial loading condition is considered to investigate the number of iterations required for the convergence of the Newton-Raphson method during plastic deformation analysis. In this study, incompressible plastic deformation is considered, and the associated flow rule is assumed. The modified returnmapping method is implemented using the ABAQUS UMAT subroutine and effective in reducing the number of iterations in the Newton-Raphson method. The anisotropic tensile behavior is computed using the 3-dimensional FEM for two tensile specimens manufactured along orthogonal additive directions.

본 연구에서는 경기도내 유통매장 및 온라인에서 유통 중인 과일류 18품목과 박과과채류 2품목 114건의 시료를 구입하였다. 과피와 과육을 분리한 후 GC-NPD, GC-ECD, GC-MSMS, LC-MSMS를 이용하여 341종 잔류농약 분석 을 진행했다. 과일 전체(과피+과육)를 분석했을 때 48건의 시료에서 검출이 되었고 부적합은 없었으며 0.0025- 0.1663 mg/kg의 검출범위를 나타냈다. 과피에서는 85건에 서 0.0026-4.7185 mg/kg의 검출범위를 보이며 분리 전과 비교했을 때 높은 검출량을 보였다. 과육에서는 8건의 검 출이 있었으며 검출범위는 0.0021-0.0993 mg/kg 로 나타났 다. 대부분의 과피에서 농산물의 잔류허용기준 이하의 농 약이 검출되었고 키위 과피에서 기준 0.05 mg/kg인 deltamethrin이 0.1020 mg/kg의 검출량을 보였다. 잔류허용 기준은 과일 전체에 대한 기준이기 때문에 섭취에 부적합 한 것은 아니지만 더욱 안전하고 건강한 과피 섭취를 위 해 세척 후 과일 그대로를 섭취할 것을 권장하며 과피와 과육에 대한 지속적인 모니터링이 필요한 것으로 보여진다