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.

Effects of substrate bed interior environments on mushroom qualities were investigated in oyster mushroom cultivation facilities in which either Reversible Air-Circulation Fans (RACF) blowing air in two directions (upwards and downwards) or customary Convection Fans (CF) with air blowing only upwards were operated throughout the cultivation period. Two days before harvest, the deviation ranges of the bed interior temperature and relative humidity in the facility using RACF were in the ranges of 1.0-1.3oC and 7.8-9.0% in the first growing cycle, and within 0.7-1.1oC and 10.0-11.4% in the second cycle. In the facility using CF, the ranges of variation in the indoor environment parameters (5.8-6.4oC and 21.3-23.1% in the first growing cycle, and 3.4-5.7oC and 14.6-18.3% in the second growing cycle) were much enlarged compared to those associated with RACF. These results strongly indicate that RACF significantly enhances air uniformity. Some mushroom qualities differed between growing cycles. For instance RACF in the first cycle gave somewhat better qualities than CF, but some qualities, like pileus diameter and stipe length, were slightly lower than those described for CF in the second cycle when the cultivation substrate weakened. The observation that some qualities worsened under RACF conditions, despite better air uniformity during the growing cycle, revealed the possibility that downward wind may exert a non-negligible negative effect on mushroom growth. Therefore in the future, making wind measurements on the interior and exterior of substrate beds is necessary to obtain insights into their influences on mushroom qualities. The RACF operation manual needs to be edited to convey this necessity.

목적: 본 연구의 목적은 운동심상 훈련이 심폐 기능에 미치는 효과를 확인하는 것이다. 방법: 본 연구는 20대 성인 남성 26명을 대상으로 실시하였다. 참가자는 각각 13명의 참가자를 고려하여 운동심상 훈련 군과 대조군으로 무작위로 할당되었다. 측정 방법으로는 트레드밀에서 심장부하 검사를 실시하였고, 최대산소섭취량, 운동 시간 및 회복 심박수를 측정하였다. 운동심상 훈련군은 일주일에 5번 운동심상 훈련을 적용하였다. 본 연구에서는 군 내 결과를 확인 하기 위하여 대응 t 검증을 하였고, 군간 비교를 위하여 독립 t검증을 실시하였다. 결과: 최대 산소 섭취량은 각 군의 전후 비교와 각 군 간의 비교에서 유의한 차이를 보였다. 운동심상 훈련군은 대조군에 비해 운동시간에 유의한 변화가 있었다. 회복 심박수에는 유의한 차이가 없었다. 결론: 본 연구에서는 운동심상 훈련군에서 최대산소섭취량 및 운동 시간을 개선하지만 회복 심박수에는 영향을 미치지 않는 것으로 나타났다. 따라서 운동심상 훈련은 심폐 기능 강화를 위한 프로그램으로 고려할 가치가 있다

국내 음식부산물 발생량은 연간 약 500만톤으로 그 중 70 %가량은 퇴비화 또는 사료화로 자원화되고 있다. 최근 비료공정규격상 음식부산물 건조분말(DFP)이 혼합유기질비료 및 유기복합비료의 원료로 사용할 수 있게 되었지만 아직 적정사용기준에 대한 설정이 미흡한 상태이다. 이에 본 연구는 수집 시기별 음식부산물 건조분말의 화학적 특성을 평가하고 음식부산물 건조분말이 혼합된 혼합유기질비료의 사용량에 따른 작물 및 토양화학성 변화에 대해 평가하고자 하였다. 처리구는 무처리(NF), 무기질비료처리구(NPK, N-P2O5-K2O=32-7.8-19.8 kg 10a-1), 음식부산물 건조분말 단독처리구(DFP), 시판혼합유기질비료(MOF), 음식부산물 건조분말 혼합유기질비료 처리구(DFPMOF)이며 DFPMOF 처리구는 100, 200, 400 및 600%로 구분하여 설정하였다. DFP, MOF 및 DFPMOF 처리구는 질소비료 사용량을 기준으로 하여 비료처리를 하여 작물 재배실험을 진행하였다. 음식부산물의 화학적 특성은 시기별에 따라서 유의적인 차이가 없었으며 중금속 함량 또한 기준에 적합한 수준이었다. 배추 생산량은 DFPMOF 처리구가 6,280 kg 10a-1로 NPK처리구(7,000 g kg-1)와 가장 유사하였으며 질소이용효율 또한 유사한 경향이었다. 토양 pH는 DFPMOF 사용량이 증가함에 따라 감소하는 경향이었으며, EC, OM 및 Ex. K는 DFPMOF 사용량이 증가함에 따라 감소하는 경향이었다. 이를 통해 DFPMOF 는 질소비료사용량 기준으로 처리하였을 때 가장 적합할것으로 판단되나, 적정사용기준을 설정하기 위해서는 장기간 연용시험을 통한 환경영향평가가 필요할 것으로 사료된다.

Probiotic strain is known to regulate the immune system by colonizing in the intestine and interact with intestinal cell receptors of lymphoid tissue. In this study, safety of Streptococcus thermophilus KCTC14471BP and silk fibroin coating effects was evaluated with respect to mucin binding abilities and immune system modulation. S. thermophilus KCTC14471BP was coated with silk fibroin by adding 1% water-soluble calcium and 0.1% silk fibroin. S. thermophilus KCTC14471BP showed the high activities of leucine arylamidase and β-galactosidase. Regarding the antibiotic resistance tests, S. thermophilus KCTC14471BP was susceptible to ampicillin, vancomycin, gentamicin, kanamycin, streptomycin, erythromycin, clindamycin, tetracycline, and chloramphenicol. S. thermophilus KCTC14471BP coated with silk fibroin showed the improved mucin binding ability from 16.1% to 71.3% and was confirmed to have no cytotoxicity against RAW 264.7 macrophage. S. thermophilus KCTC14471BP coated with silk fibroin showed dose-dependently significant increases in pro-inflammatory cytokines IL-1β, IL-6, and TNF-α. These results suggested that S. thermophilus KCTC14471BP can be expected as a promising probiotic bacteria for applications to food industries such as fermentation or functional foods.

Purpose: This study aimed to gain an in-depth understanding by analyzing and exploring the work experience of infection control nurses (ICNs) in response to the prolonged COVID-19 pandemic. Methods: Data were collected from 14 ICNs, (two in in-depth interviews and 12 in groups of six) from February 19, 2021, to March 20, 2021, and were analyzed according to the content. Results: In the prolonged COVID-19 pandemic, ICNs took the lead in responding to infectious diseases, where they felt pressure in doing everything. In addition, they were confused by a lack of workforce and undetailed job plans. ICNs have been exhausted by insufficient support and system, such as the lack of support in the hospital, communication with health authorities, and difficulties with patients and visitors. However, ICNs settle with the help and encouragement of those around them. For example, pride in the work that only ICN can do, change in the cooperation of hospitals, and development of ICNs’ unique method of perseverance. Conclusion: During the COVID-19 pandemic, ICNs experienced structural, physical, and mental difficulties at work. Nevertheless, the study found that a driving force enabled ICNs to endure, and that to efficiently respond to new infectious diseases in the future, it is necessary to secure ICNs and strengthen them.

필로티 공간은 일반적인 건축부재와 달리 부재가 외기와 접해 있고 실내에서 발생 가능한 화재와 가연물의 종류 및 배치 등이 달라 다양한 화재의 위험으로부터 노출되어 있다. 필로티 구조는 기둥으로만 이루어진 사방이 트인 구조로 인해 화 재가 발생할 경우 화재피해를 입은 기둥은 강도 및 강성이 저감되고 부재의 저항성이 저하되므로 단시간 안에 온도가 상승하여 구조체에 영향을 미친다. 이러한 문제점이 발생한다면 건축물 파손으로 인해 피난로를 차단당하여 많은 인명피해가 일어날 것 으로 사료된다. 본 연구에서는 다가구주택의 필로티 공간에서 화재 발생으로 인해 철근콘크리트 기둥에 미치는 화재영향을 확 인하고자, 기둥 국부화재실험을 통해 보강재에 따른 RC 기둥의 온도분포 및 파괴양상을 검토하였다.

This study was conducted to examine the dry matter yield and weed control of alfalfa according to postemergence herbicides treatment during spring seeding alfalfa. The seeding time of alfalfa was April 21, 2021, the seeding amount was 20 kg/ha, and the seeding method was by 20 cm wide. The alfalfa harvest was carried out at the early bloom stage (10% of flowering), and the harvest date was June 29, 2021. The test treatments were non herbicide (NH), hand weeding (HW), herbicide 1 (Trifluralin, H1), herbicide 2 (S-metolachlor, H2), herbicide 3 (Alachlor, H3), and herbicide 4 (Pendimethalin, H4). Alfalfa plant height was significantly highest in H2 (62.1±1.4 cm) followed by H3 (61.7±1.6 cm), HW (58.5±1.0 cm), H1 (57.2±1.3 cm), H4 (56.1±1.3 cm), and NH (54.1±1.2 cm) (p<0.05). Based on HW, H2 and H3 were high and H1 and H4 were short, but NH was significantly shorter than HW and H1~H4 (p<0.05). The dry matter yield of alfalfa in NH, HW, H1, H2, H3, and H4 were 717.2±94.2, 2,613.8±254.1, 1,667.8±94.1, 2,498.3±120.2, 2,435.0±118.3, and 1,793.7±354.3 kg/ha. HW is the highest among them (p<0.05). The feed composition of alfalfa was 22~24% of the dry matter yield, and the CP content were significantly higher in NH (23.6 %) (p<0.05). The NH had higher (p<0.05) NDF and ADF, but RFV was lower (p<0.05). The weed plant height was NH 98.0±3.3cm, HW 73.3±1.7 cm, H1 91.9±1.5 cm, H2 53.3±5.8 cm, H3 81.4±3.5 cm and H4 96.6±2.2 cm, and H2 was significantly smallest in the group (p<0.05). The weed dry matter yield was NH 4,770.4±232.5 kg/ha, HW 316.3±91.9 kg/ha, H1 2,353.4±173.7 kg/ha, H2 114.5±10.2 kg/ha, H3 752.7±440.6 kg/ha and H4 2,220.6±775.6 kg/ha. The weed control value was HW 94.1%, H1 53.5%, H2 98.2%, H3 84.9%, H4 48.7%, the weed value of H2 is similar to weed control value of HW. Considering the above results, postemergence herbicide treatment controlled weeds by more than 50% compared with no treatment, and among herbicides, H2 (S-metolachlor) was found to be on a similar level to hand weeding.

Conventionally, metal materials are produced by subtractive manufacturing followed by melting. However, there has been an increasing interest in additive manufacturing, especially metal 3D printing technology, which is relatively inexpensive because of the absence of complicated processing steps. In this study, we focus on the effect of varying powder size on the synthesis quality, and suggest optimum process conditions for the preparation of AlCrFeNi high-entropy alloy powder. The SEM image of the as-fabricated specimens show countless, fine, as-synthesized powders. Furthermore, we have examined the phase and microstructure before and after 3D printing, and found that there are no noticeable changes in the phase or microstructure. However, it was determined that the larger the powder size, the better the Vickers hardness of the material. This study sheds light on the optimization of process conditions in the metal 3D printing field.