• Title/Summary/Keyword: 나노과학

Search Result 972, Processing Time 0.038 seconds

Aromatic Agriculture: Volatile Compound-Based Plant Disease Diagnosis and Crop Protection (향기농업: 휘발성 물질을 이용한 식물병 진단과 방제)

  • Riu, Myoungjoo;Son, Jin-Soo;Oh, Sang-Keun;Ryu, Choong-Min
    • Research in Plant Disease
    • /
    • v.28 no.1
    • /
    • pp.1-18
    • /
    • 2022
  • Volatiles exist ubiquitously in nature. Volatile compounds produced by plants and microorganisms confer inter-kingdom and intra-kingdom communications. Autoinducer signaling molecules from contact-based chemical communication, such as bacterial quorum sensing, are relayed through short distances. By contrast, biogenic volatiles derived from plant-microbe interactions generate long-distance (>20 cm) alarm signals for sensing harmful microorganisms. In this review, we discuss prior work on volatile compound-mediated diagnosis of plant diseases, and the use of volatile packaging and dispensing approaches for the biological control of fungi, bacteria, and viruses. In this regard, recent developments on technologies to analyze and detect microbial volatile compounds are introduced. Furthermore, we survey the chemical encapsulation, slow-release, and bio-nano techniques for volatile formulation and delivery that are expected to overcome limitations in the application of biogenic volatiles to modern agriculture. Collectively, technological advances in volatile compound detection, packaging, and delivery provide great potential for the implementation of ecologically-sound plant disease management strategies. We hope that this review will help farmers and young scientists understand the nature of microbial volatile compounds, and shift paradigms on disease diagnosis and management to aromatic (volatile-based) agriculture.

Toxicity assessment of food additive(E171) in aquatic environments (식품첨가물 E171이 수생물에 미치는 독성 평가)

  • In-Gyu Song;Kanghee Kim;Hakwon Yoon;June-Woo Park
    • Korean Journal of Environmental Biology
    • /
    • v.41 no.1
    • /
    • pp.41-53
    • /
    • 2023
  • E171, a mixture of titanium dioxide, has been widely used as a food additive due to its whitening effect and low toxicity. However, it has been proven that E171 is no longer safe for public health. So far, there are insufficient studies on the toxic effects of E171 on organisms especially using standardized test methods. In this study, toxicity assessments of E171 to two aquatic species, water flea (Daphnia magna) and zebrafish (Danio rerio), were performed using modified standardized test methods based on the physicochemical properties of E171. The hydrodynamic diameter, polydispersity index, and turbiscan stability index (TSI) were measured to ensure the dispersion stability of E171 in exposure media during the test period. The EC50 for immobilization of water flea was 141.7 mg L-1 while zebrafish was not affected until 100 mg L-1 of E171. Measurements of reactive oxygen species (ROS) and antioxidant enzyme activities confirmed that E171 induced oxidative stress, leading to the activation of superoxide dismutase and catalase in both water flea and zebrafish, although the expression of antioxidant enzyme genes differed between species. These results suggested the potential risk of E171 to aquatic organisms and provided toxicological insights into the impacts of E171 on the environment.

Fabrication of Radar Absorbing Shells Made of Hybrid Composites and Evaluation of Radar Cross Section (하이브리드 복합재를 이용한 레이더 흡수 쉘의 제작 및 레이더 단면적 평가)

  • Jung, Woo-Kyun;Ahn, Sung-Hoon;Ahn, Bierng-Chearl;Park, Seoung-Bae;Won, Myung-Shik
    • Composites Research
    • /
    • v.19 no.1
    • /
    • pp.29-35
    • /
    • 2006
  • The avoidance of enemy's radar detection is very important issue in the modem electronic weapon system. Researchers have studied to minimize reflected signals of radar. In this research, two types of radar absorbing structure (RAS), 'C'-type shell and 'U'-type shell, were fabricated using fiber-reinforced composite materials and their radar cross section (RCS) were evaluated. The absorption layer was composed of glass fiber reinforced epoxy and nano size carbon-black, and the reflection layer was fabricated with carbon fiber reinforced epoxy. During their manufacturing process, undesired thermal deformation (so called spring-back) was observed. In order to reduce spring-back, the bending angle of mold was controlled by a series of experiments. The spring-back of parts fabricated by using compensated mold was predicted by finite element analysis (ANSYS). The RCS of RAS shells were measured by compact range and predicted by physical optics method. The measured RCS data was well matched with the predicted data.

QRAS-based Algorithm for Omnidirectional Sound Source Determination Without Blind Spots (사각영역이 없는 전방향 음원인식을 위한 QRAS 기반의 알고리즘)

  • Kim, Youngeon;Park, Gooman
    • Journal of Broadcast Engineering
    • /
    • v.27 no.1
    • /
    • pp.91-103
    • /
    • 2022
  • Determination of sound source characteristics such as: sound volume, direction and distance to the source is one of the important techniques for unmanned systems like autonomous vehicles, robot systems and AI speakers. There are multiple methods of determining the direction and distance to the sound source, e.g., using a radar, a rider, an ultrasonic wave and a RF signal with a sound. These methods require the transmission of signals and cannot accurately identify sound sources generated in the obstructed region due to obstacles. In this paper, we have implemented and evaluated a method of detecting and identifying the sound in the audible frequency band by a method of recognizing the volume, direction, and distance to the sound source that is generated in the periphery including the invisible region. A cross-shaped based sound source recognition algorithm, which is mainly used for identifying a sound source, can measure the volume and locate the direction of the sound source, but the method has a problem with "blind spots". In addition, a serious limitation for this type of algorithm is lack of capability to determine the distance to the sound source. In order to overcome the limitations of this existing method, we propose a QRAS-based algorithm that uses rectangular-shaped technology. This method can determine the volume, direction, and distance to the sound source, which is an improvement over the cross-shaped based algorithm. The QRAS-based algorithm for the OSSD uses 6 AITDs derived from four microphones which are deployed in a rectangular-shaped configuration. The QRAS-based algorithm can solve existing problems of the cross-shaped based algorithms like blind spots, and it can determine the distance to the sound source. Experiments have demonstrated that the proposed QRAS-based algorithm for OSSD can reliably determine sound volume along with direction and distance to the sound source, which avoiding blind spots.

A case study on the application of service design in a tertiary care hospital - Focusing on patient and Medical staff experience data at a Regional emergency medical center - (상급종합병원 서비스디자인 적용 단일 사례연구 -권역응급의료센터의 환자와 의료진 경험 데이터를 중심으로-)

  • Choi, Jugnmin;Ahn, Jinho
    • Journal of Service Research and Studies
    • /
    • v.13 no.4
    • /
    • pp.113-130
    • /
    • 2023
  • This study is a single case study of the application of service design in a regional emergency medical centre of a senior general hospital, focusing on the experiences of patients and medical staff. It aims to measure and improve the experience of healthcare services using service design techniques and to verify their effectiveness. A qualitative case study centred on ethnography and design workshops was conducted to collect in-depth experience data from patients and medical staff. The study identified key experiential differences between patients and healthcare workers, with a particular focus on the challenges faced in emergency medical services. The qualitative data collected through patient and healthcare worker interviews and design thinking workshops were analysed and incorporated into the design in order to understand the complex dynamics of the regional emergency medical centre environment. The results of the study highlighted the need to improve communication, manage patient flow, and improve the environment in three main aspects of the current state of design reflecting the needs of patients and medical staff. By analysing the differences in the specific needs of the two groups of patients and medical staff, a design-led implementation process can be applied to improve the services of the regional emergency medical centre. This study highlights the role and importance of design in healthcare and provides an efficient way to bridge the gap between theoretical research and practical design implementation. This will contribute to creating a faster, more effective, and more satisfying healthcare experience. It is hoped that this will be a new opportunity to see service design as a key to a new innovation process for the satisfaction of both patients and medical staff.

Improved Method of License Plate Detection and Recognition using Synthetic Number Plate (인조 번호판을 이용한 자동차 번호인식 성능 향상 기법)

  • Chang, Il-Sik;Park, Gooman
    • Journal of Broadcast Engineering
    • /
    • v.26 no.4
    • /
    • pp.453-462
    • /
    • 2021
  • A lot of license plate data is required for car number recognition. License plate data needs to be balanced from past license plates to the latest license plates. However, it is difficult to obtain data from the actual past license plate to the latest ones. In order to solve this problem, a license plate recognition study through deep learning is being conducted by creating a synthetic license plates. Since the synthetic data have differences from real data, and various data augmentation techniques are used to solve these problems. Existing data augmentation simply used methods such as brightness, rotation, affine transformation, blur, and noise. In this paper, we apply a style transformation method that transforms synthetic data into real-world data styles with data augmentation methods. In addition, real license plate data are noisy when it is captured from a distance and under the dark environment. If we simply recognize characters with input data, chances of misrecognition are high. To improve character recognition, in this paper, we applied the DeblurGANv2 method as a quality improvement method for character recognition, increasing the accuracy of license plate recognition. The method of deep learning for license plate detection and license plate number recognition used YOLO-V5. To determine the performance of the synthetic license plate data, we construct a test set by collecting our own secured license plates. License plate detection without style conversion recorded 0.614 mAP. As a result of applying the style transformation, we confirm that the license plate detection performance was improved by recording 0.679mAP. In addition, the successul detection rate without image enhancement was 0.872, and the detection rate was 0.915 after image enhancement, confirming that the performance improved.

Physicochemical properties of dried Saururus chinensis and the antioxidative activities of water and 70% ethanol extracts (덖음온도를 달리하여 전저리한 삼백초 건조물의 이화학적 특성 및 물과 70% 에탄올 추출물의 항산화효과)

  • Kang, Myung-Hwa;An, Su-Mi;Kim, Do-Hee
    • Journal of Nutrition and Health
    • /
    • v.52 no.4
    • /
    • pp.399-407
    • /
    • 2019
  • Purpose: This study was conducted to evaluate the physicochemical properties of different batches of Saururus chinensis using different roasting temperature that were dried at different using different roasting temperatures and their were determined the antioxidative activities of water and 70% ethanol extracts. Methods: Extracts were examined for the total phenolic acid content, the and flavonoids contents and the antioxidant properties, including DPPH radical scavenging activity, ABTs scavenging activity and, the reducing power. Results: Moisture content was significantly higher in the LSC and the crude ash content was significantly higher in the HSC. The crude protein content was higher in the LSC (although not significantly), and the crude fat and carbohydrate contents were higher in the HSC (although not significantly). The total phenolic content was lower in the samples extracted with water, but there was no significant difference. However, the extracts extracted with 70% ethanol at a high drying temperature were significantly higher. The low temperature and high drying temperature batches of Saururus chinensis were significantly higher in the samples extracted with 70% ethanol than those extracted with 70% ethanol. The total phenolic acid content, the total flavonoid content and the electron donating ability were highest in the ethanol extract of Saururuschinensis treated at a high temperature. However, the ABTs radical activity was highest in the water extracted, high-temperature treated Saururuschinensis. The 70% ethanol extract of high temperature roasted Saururuschinensis had the highest antioxidative activities of all the Saururuschinensis batches. Conclusion: The total phenolic acid contents, total flavonoid contents, electron donating activity and reducing power activity were highest in all the 70% ethanol extraction batches of the high-temperature treated samples.

The Role of ROS-NF-κB Signaling Pathway in Enhancement of Inflammatory Response by Particulate Matter 2.5 in Lipopolysaccharide-stimulated RAW 264.7 Macrophages (RAW 264.7 대식세포에서 지질 다당류에 의한 미세먼지(PM2.5) 유발 염증 반응 증진에 미치는 ROS-NF-κB 신호 전달 경로의 역할)

  • Kwon, Da Hye;Kim, Da Hye;Kim, Min Yeong;Hwangbo, Hyun;Ji, Seon Yeong;Park, Seh-Kwang;Jeong, Ji-Won;Kim, Mi-Young;Lee, Hyesook;Cheong, JaeHun;Nam, Soo-Wan;Hwang, Hye-Jin;Choi, Yung Hyun
    • Journal of Life Science
    • /
    • v.31 no.12
    • /
    • pp.1110-1119
    • /
    • 2021
  • The purpose of this study was to investigate whether the inflammatory response in lipopolysaccharide (LPS)-treated RAW 264.7 macrophages could be promoted by particulate matter 2.5 (PM2.5) stimulation. To this end, the levels of inflammatory parameters, reactive oxygen species (ROS) and inflammation-regulating genes were investigated in RAW 264.7 cells treated with PM2.5 in the presence or absence of LPS. Our results showed that the production levels of pro-inflammatory mediators (nitric oxide and prostaglandin E2) and cytokines (interleukin-6 and -1β) were significantly increased by PM2.5 stimulation in LPS-treated RAW 264.7 cells, which was correlated with increased expression genes involved in their production. In addition, when LPS-treated RAW 264.7 cells were exposed to PM2.5, nuclear factor-kappaB (NF-κB) expression was further increased in the nucleus, and the expression of inhibitor of NF-κB as well as NF-κB in the cytoplasm was decreased. These results suggest that the co-treatment of PM2.5 and LPS further increases the activation of the NF-κB signaling pathway compared to each treatment alone, thereby contributing to the promotion of transcriptional activity of inflammatory genes. Furthermore, although the generation of ROS was greatly increased by PM2.5 in LPS-treated RAW 264.7 cells, the NF-κB inhibitor did not reduce the generation of ROS. In addition, when the generation of ROS was artificially suppressed, the production of inflammatory mediators and the activation of NF-κB were both abolished. Therefore, our results suggest that the increase in the NF-κB-mediated inflammatory response induced by PM2.5 in LPS-treated RAW 264.7 macrophages was a ROS generation-dependent phenomenon.

Probiotic Effects of Lactobacillus plantarum Strains Isolated from Kimchi (김치에서 분리한 Lactobacillus plantarum 균주들의 프로바이오틱 효과)

  • Lee, Xue-Mei;Lee, Hyun Ah;Kweon, Meera;Park, Eui-Seong;Park, Kun-Young
    • Journal of the Korean Society of Food Science and Nutrition
    • /
    • v.45 no.12
    • /
    • pp.1717-1724
    • /
    • 2016
  • Probiotic effects of Lactobacillus plantarum pF1 NITE-P1462 (Lp-pF1), L. plantarum KCCM 11352P (Lp-PNU), L. plantarum CBT LP3 KCTC 10782BP (Lp-CB), and L. plantarum KCTC 3099 (Lp-3099) isolated from kimchi and Lactococcus lactis KFCC 11510P (L-lactis) isolated from Doenjang were studied. Resistance to gastric and bile acid, adhesion to intestines in colon cells, thermal stability, and antioxidative and in vitro anticancer effects in HT-29 cancer cells were evaluated. L. plantarum strains showed improved tolerance of gastric and bile acids than L-lactis. Lp-pF1 had better adhesion ability in the intestine than Lp-PNU, Lp-3099, and L-lactis. Lp-pF1 also showed better heat resistance at $50^{\circ}C$, $70^{\circ}C$, and $80^{\circ}C$ than Lp-CB, Lp-3099, and L-lactis. In addition, Lp-pF1 exhibited greater antioxidant activity by scavenging DPPH radicals or hydroxyl radicals and anticancer effects in MTT assay than others. Taken together, these results suggest that L. plantarum isolated from kimchi showed higher probiotic activities with antioxidant and anticancer properties than Lac. lactis isolated from Doenjang. Lp-pF1 revealed the best probiotic activities among L. plantarum and could be used as a promising potential probiotics.

Performance Evaluation of Fabric Sensors for Movement-monitoring Smart Clothing: Based on the Experiment on a Dummy (동작 모니터링 스마트 의류를 위한 직물 센서의 성능 평가: 더미 실험을 중심으로)

  • Cho, Hyun-Seung;Park, Sun-Hyeong;Kang, Da-Hye;Lee, Kang-Hwi;Kang, Seung-Jin;Han, Bo-Ram;Oh, Jung-Hoon;Lee, Hae-Dong;Lee, Joo-Hyeon;Lee, Jeong-Whan
    • Science of Emotion and Sensibility
    • /
    • v.18 no.4
    • /
    • pp.25-34
    • /
    • 2015
  • TThis study explored the requirement of fabric sensor that can measure the motion of the joint effectively by measuring and analyzing the variation in electric resistance of a sensor in accordance with bending and stretching motion of the arm by the implementation of a motion sensor utilizing conductive fabric. For this purpose, on both sides of two kinds of knitted fabric, namely 'L' fabric and 'W' fabric Single Wall Carbon Nano-Tube(SWCNT) was coated, fabric sensor was developed by finishing them in a variety of ways, and the sensor was attached to the arm band. The fabric sensor consisted of total 48 cases, namely background fabric for coating, the method of sensor attachment, the number of layer of sensors, the length of sensor, and the width of sensor. The performance of fabric motion sensors in terms of a dummy arm, that is, a Con-Trex MJ with 48 arm bands around it was evaluated. For each arm band, a total of 48, fastened around the dummy arm, it was adjusted to repeat the bending and stretching at the frequency : 0.5Hz, ROM : $20^{\circ}{\sim}120^{\circ}$, the voltage was recorded for each case after conducting three sets of repeat measurement for a total of 48 cases. As a result of the experiment, and as a consequences of the evaluation and analysis of the voltage based on the uniformity of the base line of the peak-to-peak voltage(Vp-p), the uniformity of Vp-p within the same set, and the uniformity of the Vp-p among three sets, the fabric sensors that have been configured in SWCNT coated 'L' fabric / welding / two layers / $50{\times}5mm$, $50{\times}10mm$, $100{\times}10mm$, and SWCNT coated 'W' fabric / welding / two layers / $50{\times}10mm$ exhibited the most uniform and stable signal value within 5% of the total variation rate. Through all these results of the experiment, it was confirmed that SWCNT coated fabric was suitable for a sensor that can measure the human limb operation when it was implemented as a fabric sensor in a variety of forms, and the optimal sensor types were identified.