This study investigated the noise reduction effect according to the structure of the sound-absorption and insulating materials in order to maximize the noise reduction effect in various noise environments. For this purpose, the transmission loss according to the change in hole size of the performated plate in sound-absorption and insulating board was predicted using an CAE model. The sound-absorption and insulating board was modeled and the computation of the transmission loss was performed after applying the physical properties and boundary conditions. The pure sounds of 32Hz to 4,000Hz were generated, and the analysis was performed by changing the diameter and pitch of the perforated plate. It was confirmed that the influence of the diameter and pitch of the perforated plate is closely related to the structure that make up the sound-absorption and insulating material. In order to effectively reduce the variously changing noises, it is believed that a method of improving transmission loss for each frequency band of interest is needed by changing the structure of the sound-absorption and insulating material so that the diameter and pitch of the perforated plate can be changed.
해양공간계획(Marine spatial planning)은 해양의 합리적인 이용과 지속 가능한 해양 공간 활용을 위한 중요한 요소이다. 특히 어업활동 보호구역은 지속 가능한 어업을 위한 핵심 용도구역으로, 해양공간계획 경계 내에서 약 45.6%를 차지한다. 그러나, 현재 어업활동보호구역의 지정 과 평가는 미래 수요와 잠재적 가치를 충분히 반영하지 못하고 있으며, 중장기 계획 수립을 위한 보다 합리적인 평가 방법과 예측 도구가 필요한 상황이다. 이러한 문제를 해결하기 위해, 본 연구는 어업활동보호구역 내 주요 어종인 고등어, 갈치, 멸치, 참조기를 대상으로 어종 분포 예측을 시도하고, 현재 용도구역과의 비교를 통해 예측 도구의 가능성을 평가하였다. 한편, IPCC 6차 기후변화 시나리오(SSP1-2.6 및 SSP5-8.5)를 적용한 종분포 모델(MaxEnt)을 사용하여 미래 기후변화에 따른 어종의 이동 및 분포 변화를 분석한 결과, 고등어, 갈치, 참조기의 분포 면적은 현재보다 약 28~86% 증가했으나, 멸치의 분포 면적은 약 6~11% 감소했다. 이 결과를 바탕으로 주요 4종의 종풍부도 지도를 작성하였으며, 해양공간계획 경 계 내에서 ‘높음’으로 평가된 종풍부도 해역과 어업활동보호구역이 중복되는 비율은 약 15%, SSP1-2.6 시나리오에서 21%, SSP5-8.5 시나리오에서 34%로 증가하였다. 연구 결과는 향후 용도구역 평가나 유보구역 변경 시 과학적 근거로 활용될 수 있으며, 어종의 현재 종분포와 기후변화에 따 른 분포 예측을 통해 현재 용도구역 평가의 한계를 보완하고, 지속 가능한 유용 해양 자원의 이용을 위한 계획 수립에 기여할 것으로 판단된다.
기후변화는 연안지역에 심각한 영향을 미치고 있으며 그 영향이 점점 증가할 것이라고 예상되는 바, 최근 기후변화 적응 및 리스크 평가에 있어 많은 연구들이 취약성과 함께 회복탄력성 개념을 이용하고 있다. 본 연구의 목적은 기후변화 적응을 위한 연안재해 회복탄력성 측정 모형을 개발하는 것이다. 측정 모형 개발에 앞서 연안재해 회복탄력성에 대한 광범위한 문헌검토를 통해 취약성과 회복 탄력성에 대한 조작적 정의와 함께 여러 피드백 메커니즘이 포함된 개념적 프레임워크를 작성하였다. 연안재해 회복탄력성 측정 모형은 네 가지 측정값(MRV, LRV, RTSPV, ND)과 연안재해 회복탄력성 복합 지수(CRI)를 포함하고 있으며, 개발된 지수는 국내 연안침식 사례에 적용되었다. 또한 지수 등급에 따른 지역적 분석이 수행되었다. 연구 결과, 네 가지 회복탄력성 측정값을 통해 각 지점이 가지는 연안침식 회복탄력성의 다양한 특성을 파악할 수 있음을 확인하였다. 연안 회복탄력성 복합 지수의 매핑 결과 서해안 및 남해안 지역에 비해 동해 안 지역들은 연안침식 회복탄력성이 상대적으로 떨어지는 것으로 나타났다. 본 연구의 회복탄력성 측정 모형은 적응 이후의 이행전략에 대한 논의를 제공하는 도구로 활용될 수 있으며, 서로 다른 취약 지역 그룹 간 정책지원에 대한 우선순위를 결정하는 데 이용 가능하다.
In this study, we designed and manufactured a large angular contact ball bearing (LACBB) with low deformation using JIS-SUJ2 steel and analyzed changes in its structural characteristics and chemical composition upon heat treatment. The bearing was produced by hot forging and heat treatment including a quenching and tempering (Q/T) process, and its properties were analyzed using 4 mm thick specimens. A difference in the size distribution of the carbide in the outer and inner parts of the bearing was observed and it was confirmed that large and non-uniform carbide was distributed in the inner part of the bearing. After heat treatment, the hardness value of the outer part increased from 13.4 HRC to 61 HRC and the inner part increased from 8.0 HRC to 59.7 HRC. As a result of X-ray diffraction (XRD) measurements, the volume fraction of the retained austenite contained in the outer part was calculated to be 3.5~4.8 % and the inner part was calculated to be 3.6~5.0 %. The surface chemical composition and the content of chemical bonds were quantified through X-ray photoelectron spectroscopy (XPS), and a decrease in C=C bonds and an increase in Fe-C bonds were confirmed.
To improve usability of super sweet corn, extracts were prepared with hydrolytic enzyme and changes in physicochemical and antioxidant properties were analyzed. Soluble solids and reducing sugars contents were higher in all enzyme treatment groups than in the control. When enzyme treatment time increased, contents of soluble solids and reducing sugars were also increased. There was no significant difference in lightness between treatment groups, with redness showing the highest value in the control and yellowness showing the highest value in the invertase treatment group. Free sugar content in the control was the lowest. However free sugar content in the enzyme combination treatment group was increased by more than four times compared to that in the control. Contents of ascorbic acid, flavonoids and polyphenols were higher in the enzyme treatment group than in the control. In particular, the enzyme combination treatment group showed the highest content. DPPH and ABTS radical scavenging abilities were significantly higher in all enzyme treatment groups than in the control. Radical scavenging abilities of cellulase treatment group and enzyme combination treatment group showed high activity. The activity increased when enzyme treatment time increased. The combined enzyme treatment method for super sweet corn was suitable for food processing.
The key to invasive pest management lies in preemptive action. However, most current research using species distribution models is conducted after an invasion has occurred. This study modeled the potential distribution of the globally notorious sweet potato pest, the sweet potato weevil (Cylas formicarius), that has not yet invaded Korea using MaxEnt. Using global occurrence data, bioclimatic variables, and topsoil characteristics, MaxEnt showed high explanatory power as both the training and test areas under the curve exceeded 0.9. Among the environmental variables used in this study, minimum temperature in the coldest month (BIO06), precipitation in the driest month (BIO14), mean diurnal range (BIO02), and bulk density (BDOD) were identified as key variables. The predicted global distribution showed high values in most countries where the species is currently present, with a significant potential invasion risk in most South American countries where C. formicarius is not yet present. In Korea, Jeju Island and the southwestern coasts of Jeollanam-do showed very high probabilities. The impact of climate change under shared socioeconomic pathway (SSP) scenarios indicated an expansion along coasts as climate change progresses. By applying the 10th percentile minimum training presence rule, the potential area of occurrence was estimated at 1,439 km2 under current climate conditions and could expand up to 9,485 km2 under the SSP585 scenario. However, the model predicted that an inland invasion would not be serious. The results of this study suggest a need to focus on the risk of invasion in islands and coastal areas.
청말·민국 시기 중국 지리교과서는 한국 관련 서술이 풍부하여 당시 중국인들이 한국을 어떻게 인식했는지 연구하는 데 유용한 공적 자료이 다. 한·중 양국은 수천 년 동안 정치, 경제, 문화 등 많은 방면에서 교류 했으며, 19세기 말 이전까지 한국은 중국 주도 하의 중화질서에서 가장 중요한 일원으로서 중국의 전통 지리 문헌에서 항상 ‘소중화’와 ‘예의지 방’으로 높은 명성을 누렸다. 그러나 20세기 들어 중국 지리교과서 속 한국의 이미지는 이전과는 확연히 달라졌다. 본 논문은 청말·민국 시기 중국의 교육 근대화 이후 편찬된 일련의 신식 지리교과서에 나타난 한국 의 개화기 및 일제강점기 관련 서술과 인식을 비교연구로 하였다. 19세 기 말 이후 한·중 양국 관계는 불평등에서 평등으로, 상하급에서 동반자 로 전환되었고 이에 따라 청말·민국시기 중국 지리교과서에 나타난 한국 의 이미지도 대체로 ‘소중화’에서 ‘후진국’으로, 그리고 다시 ‘동반자’로 바뀌는 과정을 거쳤다. 중국 지리교과서 속 한국의 이미지는 시기별로 중국이 직면한 여러 가지 현실적인 곤경에 영향을 받아 변화해 왔다. 대 중의 지리 지식과 타국 인식을 양성하는 주요 매체인 지리교과서에 대한 연구를 통해 당시 중국 정부와 교과서 편찬자가 자라나는 후속세대에게 한국을 어떻게 인식시키려고 했는지를 살펴보았다. 그리고 견문록, 신문 잡지 등 사적 자료를 연구 내용으로 한 기존의 선행 연구와 상호 검증과 보완의 관계를 형성할 수 있기를 기대한다.
Many changes in the scale and structure of the Korean rice cropping system have been made over the past few decades. Still, insufficient research has been conducted on the sustainability of this system. This study analyzed changes in the Korean rice cropping system’s sustainability from a system ecology perspective using an emergy approach. For this purpose, an emergy table was created for the Korean rice cropping system in 2011, 2016, and 202, and an emergy-based indicator analysis was performed. The emergy analysis showed that the total emergy input to the rice cropping system decreased from 10,744E+18 sej year-1 to 8,342E+18 sej year-1 due to decreases in paddy field areas from 2011 to 2021, and the proportion of renewable resources decreased by 1.4%. The emergy input per area (ha) was found to have decreased from 13.13E+15 sej ha-1 year-1 in 2011 to 11.89E+15 sej ha-1 year-1 in 2021, and the leading cause was a decrease in nitrogen fertilizer usage and working hours. The amount of emergy used to grow 1 g of rice stayed the same between 2016 and 2021 (specific emergy: 13.3E+09 sej g-1), but the sustainability of the rice cropping system (emergy sustainability index, ESI) continued to decrease (2011: 0.107, 2016: 0.088, and 2021: 0.086). This study provides quantitative information on the emergy input structure and characteristics of Korean rice cropping systems. The results of this study can be used as a valuable reference in establishing measures to improve the ecological sustainability of the Korean rice cropping system.
본 연구는 독일어권의 사물인터넷을 이용한 데이터 거래와 블록체인 기술로 인한 사회혁신을 조망하고자 한다. 먼저, 독일어권 국가에서의 빅 데이터와 블록체인 기술의 활용을 조사하기 위해 문헌 연구 및 선행 연 구 검토가 수행되었다. 또한, 데이터레이드(Datarade)와 같은 독일의 데 이터 회사 및 정부의 데이터 경제 관련 프로젝트(GAIA-X)에 대한 사례 연구가 진행되었다. 이를 통해 독일에서의 데이터 및 블록체인 활용 현 황을 파악하고, 각 산업 분야에서의 적용 사례를 식별하였다. 금융 산업 에서는 블록체인 기술을 활용하여 계좌 번호 및 구매 세부 정보를 안전 하게 저장하고 있으며, 부동산 산업에서는 임대 계약, 임대료 결제 확인 등을 블록체인을 통해 효율적으로 관리하고 있다. 특히 교육 부문에서 블록체인 기술의 활용에 대한 현지 사례 및 연구 결과를 종합하여 분석 하였다. 블록체인의 보안이라는 장점을 살려 학습자의 학습 성과나 평가, 성적 증명, 학습낙오자나 성적부진자의 학습활동 추적, 부정행위 방지, 스마트 계약을 통한 과제 관리, 평생학습증 및 학습이력부 제공 등의 방 식으로 이미 독일은 교육계에 혁신을 이루어나가고 있다. 교육 부문에서 의 이러한 조사 방법을 통해 독일에서의 기술 혁신 및 사회적 변화에 대 한 종합적인 이해를 제공하고자 한다. 이러한 결과들은 독일정부 주도의 데이터거래와 블록체인 분야의 기술혁신의 효과를 입증하기에 한국정부 의 산업혁신에도 활용할 수 있는 중요한 통찰을 제공할 것이다.
This study was conducted to analyze the effects of stand density on fire fuel (FF) changes in a Chamaecyparis obtusa forest. The study site was located in Mt. Munsu in Jeollabuk-do and consisted of a control, 30% thinning treatment (LT), and 50% thinning treatment (HT). Three-year-old seedlings were planted at a density of 3,000 trees ha-1 in 1976, and thinning was carried out in 2000. FF production was measured every 2 months by installing 3 circular litter traps 1.2 m above the ground. Litter bags containing 5 g of each leaf and branch were made and buried in the organic layer to investigate the FF decomposition rate. The decay constant was calculated after 18 months. FF accumulation was measured by collecting dry-weight organic matter from each plot using a square frame (0.09 m2) in September 2018. The FF production in LT and HT was significantly lower than that of the control (P<0.001). The leaf decay constant for HT was significantly lower than that of the control (P<0.05). The FF accumulation in HT was significantly lower than that of the control (P<0.01), but LT was not significantly different from the control. The results of this study showed that thinning decreased FF production.
Captive breeding and reintroduction are crucial strategies for conserving endangered species populations. However, fish raised in predator-free environments, show a lack of recognition of predationrelated stimuli such as chemical and visual signals. It is critical to recognize chemical signals from injured conspecifics, also known as alarm signals, and the order or shape of predators to indicate the spread of predation risk in the habitat. We conducted a laboratory experiment to determine and adjust the optimal exposure period to induce appropriate anti-predator behavior response to different types of stimuli (Chemical, Visual and Chemical+Visual) for the endangered species Microphysogobio rapidus. Our results demonstrate that predator avoidance behavior varies depending on the types of stimuli and the duration of predation risk exposure. First, the results showed captive-breed M. rapidus show lack of response against conspecific alarm signal (Chemical cue) before the predation risk exposure period and tend to increase response over predation risk exposure time. Second, response to predator (visual cue) tend to peak at 48 hours cumulative exposure, but show dramatic decrease after 72 hours cumulative exposure. Finally, response to the mixed cue (Chemical+visual) tend to peak prior to the predation risk exposure period and show reduced response during subsequent exposure periods. This experiment confirms the lack of responsiveness to conspecific alarm signals in captive-bred M. rapidus and the need for an optimal nature behavior enhancement program prior to release of endangered species. Furthermore, responsiveness to predator visual signal peak at 48 hours cumulative exposure, suggest an optimal predation risk exposure period of up to 48 hours. Key words: predator cognition, captive breeding, chemical signal, visual signal, endangered
This study aimed to investigate the dietary changes among adults living alone during the COVID-19 pandemic in the Republic of Korea. An online survey was conducted to examine dietary changes before (in 2019) and during (in 2021) the pandemic. The data from 337 adults living alone who responded to the survey were used for analysis. The proportion of the respondents reporting frequent food consumption at convenience stores (≥3 times/week) increased during the pandemic (p=0.024), and the proportion of those frequently eating ready-to-eat and ready-to-cook food (≥3 times/week) was more than doubled (p<0.001). Additionally, the proportion of those frequently consuming delivered food (≥3 times/week) increased by 2.5 times (p<0.001). In conclusion, the dietary habits of adults living alone changed significantly during the COVID-19 pandemic, which may have a negative impact on their health. Therefore, the development of customized nutrition management programs to improve the dietary habits of adults living alone during emergencies like a pandemic is deemed necessary. This study can serve as a foundation for understanding the dietary changes of adults living alone in prolonged crisis.
PURPOSES : Demonstrated performance degradation of LiDAR for vehicle and pedestrian dummy in rainy and foggy road conditions. METHODS : In real-scale rain and fog road conditions, adjust the distance between LiDAR and the measurement target from 10m to 70m (in 10m interval), measure LiDAR NPC (number of point cloud) and intensity, and compare the resulting numerical values. RESULTS : LiDAR's NPC and Intensity showed statistically significant differences by overall weather condition (normal, rain, fog), and the values were found to be larger in the order of normal>rainfall>fog. In the case of vehicles, sunder rain conditions, NPC and intensity are recognized even at 70m as in normal conditions, but under fog conditions, NPC and intensity are measured only up to 30m. In the case of pedestrians, the reflective area size is smaller than that of vehicles, so they are recognized only up to 30m in rainy conditions, and NPC and intensity are measured only up to 20m in fog conditions. CONCLUSIONS : It was confirmed that LiDAR performance deteriorates in rain and fog compared to normal.
이 연구 논문은 기후 변화에 대한 전 세계적인 우려와 온실 가스 배출 감소를 위한 필수적인 요구에 대응하여 마 이크로기공 고분자(PIM-1)의 이용을 탐구한 것이다. 연구는 PIM-1 막을 이산화탄소(CO2) 가스 분리 막으로 사용하는 현대적 인 소재로서의 응용에 집중하고 있다. 연구는 PIM-1 막의 합성, 분자량 제어, 그리고 제각각의 특성 분석 기술을 통해 포괄적 인 통찰을 제공하며, 이러한 특성 분석 기술을 통해 PIM-1의 고유한 교차결합 및 강성 구조에서 비롯된 내재적 다공성이 특 히 이산화탄소의 선택적 투과에 활용되고 있다. 논문은 PIM-1의 가교된 구조로부터 비롯된 내재적 다공성이 특히 이산화탄 소의 선택적 투과에 활용되고 있다. 논문은 PIM-1의 튜닝 가능한 화학적 특성을 강조하며, 가스 분리 막의 맞춤 및 최적화를 가능케 하는 특성에 대한 이해를 제시하고 있다. 분자량을 통제함으로써 고분자량(H-PIM-1) 막은 낮은 분자량 대비 더 뛰어 난 CO2 투과성과 선택성을 나타내며, 이를 통해 PIM-1 막의 특성을 조절하는 데 분자량의 중요성을 강조하고 있다. 연구 결 과는 PIM-1 막 특성을 조절하는 데 분자량이 중요한 역할을 하는 것을 강조하며, 이는 기후 변화의 긴급한 글로벌 도전에 대 응하기 위한 효율적이고 선택적인 CO2 포집을 위한 차세대 막 기술의 발전에 기여하고 있다.
서예의 미적 패러다임은 근본적으로 사회적 변화에 기초한 다. 현대의 서예는 현상적 측면에서 볼 때 창작의 영역에서 전 통과 다른 풍모와 특징을 나타내고 있다. 특히 인간만의 영역 이었던 서예 예술의 탄생 과정이 AI 서예 로봇이 등장하면서 혼란을 맞고 있다. 현재로선 AI의 서예 창작을 예술로 인정하 기 힘든 분위기지만 급변하는 과학기술의 발전은 미래의 서예 에 대한 추세를 예측하기 힘든 실정이다. 21세기의 서예는 현 대화를 추구하는 과정에서 과학은 물론 사회학적 요소가 매우 강조되고 있다. 이는 과거의 전통 서예와 다른 형식의 미학적 메커니즘이 새로운 패러다임으로 전환되고 있기 때문이다. 현 대 서예의 가장 큰 특징은 다원적 시각화 경향이다. 이 이면에 는 서예 미학에 대한 인식의 변화 및 새로운 창작의 형식과 관 련된 문제들이 존재한다. 현대 서예의 창작적 성향은 과거보다 더욱 실험적인 양상으로 전개되고 있다. 이에 서예의 심미적 가치 기준이나 그 미학적 특색을 가름하기는 쉽지 않다. 본고에서는 현대 서예의 변화 과정을 좀 더 체계적으로 규명 하기 위해 서예학 분야의 새로운 패러다임(Paradigm)을 제시하 였다. 현대 서예의 발전과 변화는 결코 서예 예술 내부의 자율 성만으로는 설명할 수 없다. 새로운 미적 패러다임의 발생은 필연적으로 사람이 중심이 되는 예술사회학의 각도에서 탐구해 야 한다. 진정한 의미의 현대성이란 시간의 개념이 아니라 현 대의 서예가 고대와 다른 새로운 미학적 규범의 전환을 의미한 다. 다만 오늘날 서예의 현대화 과정에서 대두되는 시각적 경 향은 이미 많은 대중들에게 환영을 받고 있지만, 아직까지는 서예계의 공통된 신념으로 정착되었다고 단언할 수 없다.
To investigate the impact of forestry projects on the carbon stocks of forests, we estimated the carbon stock change of above-ground and soil before and after forestry projects using forest type maps, forestry project information, and soil information. First, we selected six map sheet with large areas and declining age class based on forest type map information. Then, we collected data such as forest type maps, growth coefficients, soil organic matter content, and soil bulk density of the estimated areas to calculate forest carbon storage. As a result, forest carbon stocks decreased by about 34.1~70.0% after forestry projects at all sites. In addition, compared to reference studies, domestic forest soils store less carbon than the above-ground, so it is judged that domestic forest soils have great potential to store more carbon and strategies to increase carbon storage are needed. It was estimated that the amount of carbon stored before forestry projects is about 1.5 times more than after forestry projects. The study estimated that it takes about 27 years for forests to recover to their pre-thinning carbon stocks following forestry projects. Since it takes a long time for forests to recover to their original carbon stocks once their carbon stocks are reduced by physical damage, it is necessary to plan to preserve them as much as possible, especially for highly conservative forests, so that they can maintain their carbon storage function.
The characteristics and spore production of Gonji7ho, Bunhong, and Sunjung fruiting bodies were assessed at different growth stages. The shape of the Pleurotus species fruiting body starts out short and small, then takes on a typical mushroom shape as it grows. Gonji7ho has a long stalk, Bunhong has a short stalk and a wide cap, and Sunjung's cap and stalk dimensions are intermediate. Each variety displayed deep color at the beginning of growth but became steadily lighter with continued growth. The shape of the linkage between the mushroom stalk and cap changed from an initial central position to a lateral position after the growing stage. Gonji7ho cap diameter increased 7-fold from 15.5 mm (5 days of growth) to 37.9 mm (9 days of growth). Growth rates for each growth day measured using the growth percentage of the previous day were 285.5% (5 → 6th day), 182.2% (6 → 7th day), 129.4% (7 → 8th day), and 103.8% (8 → 9th day). This trend was also observed in Bunhong and Sunjung, but Bunhong’s growth rate was more rapid (4.9 fold on day 6, 2.7 fold on day 7) and continued to increase through day 9. Harvest yield, which is of greatest interest to farmers, displayed a similar trend spanning the growth period, as did cap diameter. Gonji7ho harvest yield increased rapidly until day 7 of growth (more than 177%), then growth slowed down beginning around day 8, and further decreased on day 9 (98%). Similar trends were observed in Bunhong and Sunjung. Bunhong showed characteristic rapid growth in harvest yield (4.9 fold compared to the previous day on day 6 and 2.7 fold on day 7), and the increase continued through day 9. A decrease in mushroom harvest yield commonly seen in the late growth stage is thought to be due to the death of some mushrooms and decomposition of cap tissue. Basidiospore content increased with number of growth days but decreased after day 8. Gonji7ho yielded the highest production on day 7 of growth, coinciding with harvest time, with 209,000,000 spores. This trend was also observed in Bunhong and Sunjung. These results will provide researchers with basal data and guide farmers in selecting the optimal harvest day.
This experiment investigated the effects of feed additives of Sasa quelpaertensis Nakai (SQN) extract on Landrace pigs on economic traits such as the quality, physiological characteristics, and productivity. Sixteen pigs with an average age of 154 days were selected as experimental subjects. The experiment was conducted by dividing the group into eight pigs for the supplementation group, feeding with SQN extract, and another eight for the control group feeding without SQN extract. Water was fed ad libitum. On the 30th day, there was no significant difference between meat quality and productivity. However, the glucose and thyroxine were statistically lower with the supplementation group than with the control group (p<0.05). Also, the levels of creatinine difference between 1.18 ± 0.12 ㎎/㎗ with the supplementation group and 0.70 ± 0.06 ㎎/㎗ with the control group (p<0.05). However, all serum biochemistry values were within a normal range, with no health problems. The present study will help solve the problem of reducing the diversity of plant species in Halla Mountain by increasing the availability of the SQN as a pig feed additive.
Mushrooms have a unique taste and aroma, so in the processing of mushroom products with other ingredients, a separate pre-processing step is often taken to eliminate the mushroom aroma. In this study, we analyzed the changes in the concentration of volatile compounds according to drying conditions to promote the activation of processing using the fruiting bodies of yellow oyster mushrooms(Pleurotus citrinopileatus) and pink oyster mushrooms(P. djamor). The caps and stipes of yellow oyster and pink oyster mushrooms were separated and freeze-dried at -70oC for 120 hours. Subsequently, they were hot air-dried at temperatures of 40, 50, 60, and 70oC for 24, 24, 16, and 12 hours, respectively. The dried samples were pulverized and quantitatively analyzed by SPME-GC-MS. In the case of yellow oyster mushrooms, the concentration of t-2-nonenal in caps and stipes during freeze-drying was 164.43 g/g d.w. and 174.80 g/g d.w., respectively, whereas during hot air-drying, it significantly decreased to 0.35~3.41 g/g d.w. and 0.98~59.88 g/g d.w. In a similar manner, for pink oyster mushrooms, the concentration of 1-octen-3-ol during freeze-drying in caps and stipes was 31.05 g/g d.w. and 176.17 g/g d.w., respectively, whereas during hot air-drying, it significantly decreased to 1.59~9.66 g/g d.w. and 1.96~15.77 g/g d.w. Furthermore, most volatile compounds showed a tendency to decrease in concentration as the temperature during hot air-drying increased.
This study was performed to investigate immune changes by comparing the proportion and function of immune cells in the blood under high-temperature period and convalescence temperature period in Holstein dairy cows. The experiment was conducted using Holstein dairy cows of five animals per group (60 ± 20 months old, 175 ± 78 non-day) from the National Institute of Animal Science at high-temperature period (THI: 76 ± 1.2) and convalescence temperature period (THI: 66 ± 1.3). Complete blood count results showed no change in the number of immune cells between groups. In the analysis using Flow Cytometry of PBMCs, no significant differences were observed among B cells, Helper T cells, cytotoxic T cells, and γδ T cells between groups. However, there was an increase in Th17 cells producing IL-17a, while Th1 cells decreased during the convalescence temperature period. The results of gene expression analysis using qRT-PCR in PBMCs revealed an increase in IL-10 during the convalescence temperature period, while a decrease in HSP70 and HSP90 was observed. In conclusion, the increased expression of IL-10 and the decrease in HSP expression suggest the possibility of a weak recovery from heat stress. However, the lack of observed changes in B cells, T cells, and other immune cells indicates incomplete recovery from heat stress during the convalescence temperature period.