• Title/Summary/Keyword: Flow Properties

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A Study on the Evaluation of Distribution Stability of Refrigerated Rice Cake Using Natural Antibiotics (천연항균제를 사용한 냉장떡류의 유통 안정성 평가연구)

  • Yoo, Seung Jin;Chin, Jong-eon;Oh, Sung Hoon;Ryu, Min Jung;Hwang, Kwontack
    • Journal of Chitin and Chitosan
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    • v.23 no.4
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    • pp.244-255
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    • 2018
  • Natural extract in liquid phase was adjusted to 0, 0.25, 0.5, 1, 2, and 4% concentration to check microbial changes and to measure 4, 8, $12^{\circ}C$ for refrigeration temperature. In the case of grapefruit extract, the microbial safety was maintained at all the concentrations at $4^{\circ}C$ storage, but the antimicrobial activity was maintained at $12^{\circ}C$ storage and at $8^{\circ}C$ and 21 days storage. In the case of grape seed extract, only the 4% of the culture at $8^{\circ}C$ satisfied the requirement of safety of food distribution for the last 21 days, and the safety criterion was satisfied only at 4% concentration at $12^{\circ}C$ for 18 days. Complex Scutellaria baicalensis extract showed the total number of microbial cells treated by concentration. It was confirmed that microbial flow safety was maintained at low temperature ($4^{\circ}C$). However, at $8^{\circ}C$ and $12^{\circ}C$, Exceeded the distribution limit. When polylysine was applied to brown rice cake, it showed activity in all groups except $4^{\circ}C$, but these properties were not observed at $8^{\circ}C$ and $12^{\circ}C$. At a concentration of 0.5% or more of chitosan, the growth of the microorganism is suppressed by the 21st day very stably, and a similar tendency is observed at 8 and $12^{\circ}C$, so that it may be an antimicrobial material that inhibits microorganisms. At the first day, the distribution standards for general bacterial counts were exceeded.Ethyl-pyruvate showed that microorganism safety was maintained at $4^{\circ}C$ and 1% concentration, and food safety was stable even at 2 or 4%. Glycine showed very good and stable distribution stability at $4^{\circ}C$. However, at $8^{\circ}C$ and $12^{\circ}C$, the shelf life of 14 days could not be maintained as with the addition of other antimicrobial active substances.

Exploring Twitter Follower-Networks of Startup Companies Employing Social Network Analysis and Cluster Analysis (소셜네트워크 분석과 클러스터 분석 방법을 활용한 스타트업 회사의 트위터 팔로워 네트워크에 대한 탐색적 연구)

  • Yu, Seunghee
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.14 no.4
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    • pp.199-209
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    • 2019
  • The importance of business strategy for successful social media engagement has quickly increased as more businesses engage in social media. The importance is even greater for startup companies because startup companies are genuinely new to business, and they need to increase their presence in the market, and quickly access future customers. The objective of this paper lies in exploring key indicators of social media engagements by selected startup companies. The key indicators include two aspects of social media usages by the companies: i) overall social media activities, and ii) properties of network structure of the information flow platform provided by social media service. To better assess and evaluate the key indicators of social media usages by startup companies, the indicators will be compared with those of selected large established companies. Twitter is selected as a social media service for the analysis of this paper, and using Twitter REST API, data regarding the key indicators of overall Twitter activities and the Twitter follower-network of each company in the sample are collected. Then, the data are analyzed using social network analysis and hierarchical clustering analysis to examine the characteristics of the follower-network structures and to compare the characteristics between startup companies and established companies. The results show that most indicators are significantly different across startup companies and established companies. One key interesting finding is that the startup companies have proportionally more influencers in their follower-networks than the established companies have. Another interesting finding is that the follower-networks of startup companies in the sample have higher modularity and higher transitivity, suggesting that the startup companies tend to have a proportionally larger number of communities of users in their follower-networks, and the users in the networks are more tightly connected and cohesive internally. The key business implication for the future social media engagement efforts by startup companies in general is that startup companies may need to focus on getting more attention from influencers and promoting more cohesive communities in their follower-networks to appreciate the potential benefits of social media in the early stage of business of startup companies.

Anti-inflammatory Effect of Heat-Killed Enterococcus faecalis, EF-2001 (열처리 사균체 엔테로코커스 패칼리스 EF-2001의 항염증 효과)

  • Choi, Moon-Suk;Chang, Sang-Jin;Chae, Yuri;Lee, Myung-Hun;Kim, Wan-Joong;Iwasa, Masahiro;Han, Kwon-Il;Kim, Wan-Jae;Kim, Tack-Joong
    • Journal of Life Science
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    • v.28 no.11
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    • pp.1361-1368
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    • 2018
  • Inflammation is the most common condition in the human body. Tissue damage triggers inflammation, together with vasodilation and increased blood flow at the inflamed site, resulting in edema. Inflammatory responses are also triggered by lipopolysaccharide (LPS), a Toll-like receptor Enterococcus faecalis, a gram-positive organism, has been reported to possess immunomodulatory and preventive activities; however, its use may present risks of sepsis and other systemic infections. Heat-killed Enterococcus faecalis (EF-2001) has been reported to induce antitumor activity, but its effects on inflammation are not known. In the present study, we investigated the effect of EF-2001 on LPS-induced macrophage inflammatory responses. EF-2001 treatment reduced nitric oxide (NO) production, indicating suppression of inflammatory reactions. EF-2001 showed no cytotoxicity in macrophages. Further investigation of the anti-inflammatory mechanism of EF-2001 indicated that EF-2001 reduced the LPS-induced expression of inducible nitric oxide synthase and cyclooxygenase-2. EF-2001 also reduced f the LPS induction of several inflammatory molecules involved in the nuclear factor-${\kappa}B$ ($NF-{\kappa}B$) and mitogen-activated protein kinase pathways, including ERK, JNK, and p38 phosphorylation, in a concentration-dependent manner. Additionally, EF-2001 inhibited Akt phosphorylation and increased the expression of the inhibitory ${\kappa}B$ ($I{\kappa}B$) protein, an inhibitor of $NF-{\kappa}B$. EF-2001 also inhibited the nuclear translocation of p65. These results suggest that EF-2001 has anti-inflammatory properties and may be useful for treating inflammatory diseases.

Study on the Lubricity Characteristics of Bio-heavy Oil for Power Generation by Various feedstocks (다양한 원료에 따른 발전용 바이오중유의 윤활 특성 연구)

  • Kim, Jae-Kon;Jang, Eun-Jung;Jeon, Cheol-Hwan;Hwang, In-Ha;Na, Byung-Ki
    • Journal of the Korean Applied Science and Technology
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    • v.35 no.4
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    • pp.985-994
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    • 2018
  • Bio-heavy oil for power generation is a product made by mixing animal fat, vegetable oil and fatty acid methyl ester or its residues and is being used as steam heavy fuel(B-C) for power generation in Korea. However, if the fuel supply system of the fuel pump, the flow pump, the injector, etc., which is transferred to the boiler of the generator due to the composition of the raw material of the bio-heavy oi, causes abrasive wear, it can cause serious damage. Therefore, this study evaluates the fuel characteristics and lubricity properties of various raw materials of bio-heavy oil for power generation, and suggests fuel composition of biofuel for power generation to reduce frictional wear of generator. The average value of lubricity (HFRR abrasion) for bio-heavy oil feedstocks for power generation is $137{\mu}m$, and it varies from $60{\mu}m$ to $214{\mu}m$ depending on the raw materials. The order of lubricity is Oleo pitch> BD pitch> CNSL> Animal fat> RBDPO> PAO> Dark oil> Food waste oil. The average lubricity for the five bio-heavy oil samples is $151{\mu}m$ and the distribution is $101{\mu}m$ to $185{\mu}m$. The order of lubricity is Fuel 1> Fuel 3> Fuel 4> Fuel 2> Fuel 5. Bio-heavy oil samples (average $151{\mu}m$) show lower lubricity than heavy oil C ($128{\mu}m$). It is believed that bio-heavy oil for power generation is composed of fatty acid material, which is lower in paraffin and aromatics content than heavy oil(B-C) and has a low viscosity and high acid value, resulting in inhibition of the formation of lubricating film by acidic component. Therefore, in order to reduce friction and abrasion, it is expected to increase the lubrication of fuel when it contains more than 60% Oleo pitch and BD pitch as raw materials of bio-heavy oil for power generation.

Semantic Interpretation of the Nu-Jeong Cultural Landscape During the 16~18th Century at Youngnam and Honam Area -Focusing on the Designated Cultural Properties- (16~18세기 영·호남 누정에 깃든 문화경관의 의미론적 해석 - 지정 문화재를 중심으로 -)

  • Lee, Hyun Woo
    • Korean Journal of Heritage: History & Science
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    • v.45 no.1
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    • pp.190-217
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    • 2012
  • This research has studied the building awareness of Nu-Jeong that a view of nature and aesthetic consciousness to unite the nature are inherent by considering Nu-Jeong of scholars who left fame and wealth behind and retired to hermitage in the backwoods in the 16~18 Century. This is to clarify correlation with leaving nature as it is, namely, an ideal state that scholars at the time would enjoy, through landscape awareness accepted into Nu-Jeong literature. In addition, this research has tracked the ideologic flow that acts on space formation by clarifying Korean unique meanings inherent to Nu-Jeong's cultural landscape. As a suggestion for this, the interpretation through 'Pungsu location Nu-Jeong name's analysis Nu-Jeong literature analysis', etc. was tried, so its integrated conclusion is as follows. It is not a chance that scholars of Joseon have left numerous literature works singing the nature. They already had huge interest and knowledge on the nature, and achieved active poetic exchange by sublimating the praise of nature as literature. Nu-Jeong, which was a place of exchange like this, had cleanliness of the nature and ideological purity as an oppositional space on turbid political realities. The Nu-Jeong literature drew the nature into a literature space as it is, without doing abstraction or ideation on the nature. The owner of Nu-Jeong exclusively possessed such natural landscape in grim and independent postures, so it provided a clue of Nu-Jeong cultural landscape that this research aimed to discuss. Scholars who aimed to raise wide and large vigor filled in between the sky and earth got to convince that people are born from the nature, grow in the nature and finally return to the nature. What people are born from the nature and finally return to the nature is just consistent with Taoistic and Zhua-ngzi thoughts denying human work, and leaving nature as it is or nature itself remained intact which is an ideal state. The construction at the time is a vessel containing the spirit of the times of the era. This thesis has proved that the Nu-Jeong culture of scholars located on the central line of Korean landscape was the flower of Joseon's scholar culture by interpreting it semantically.

Coarse Woody Debris (CWD) Respiration Rates of Larix kaempferi and Pinus rigida: Effects of Decay Class and Physicochemical Properties of CWD (일본잎갈나무와 리기다소나무 고사목의 호흡속도: 고사목의 부후등급과 이화학적 특성의 영향)

  • Lee, Minkyu;Kwon, Boram;Kim, Sung-geun;Yoon, Tae Kyung;Son, Yowhan;Yi, Myong Jong
    • Journal of Korean Society of Forest Science
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    • v.108 no.1
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    • pp.40-49
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    • 2019
  • Coarse woody debris (CWD), which is a component of the forest ecosystem, plays a major role in forest energy flow and nutrient cycling. In particular, CWD isolates carbon for a long time and is important in terms of slowing the rate of carbon released from the forest to the atmosphere. Therefore, this study measured the physiochemical characteristics and respiration rate ($R_{CWD}$) of CWD for Larix kaempferi and Pinus rigida in temperate forests in central Korea. In summer 2018, CWD samples from decay class (DC) I to IV were collected in the 14 forest stands. $R_{CWD}$ and physiochemical characteristics were measured using a closed chamber with a portable carbon dioxide sensor in the laboratory. In both species, as CWD decomposition progressed, the density ($D_{CWD}$) of the CWD decreased while the water content ($WC_{CWD}$) increased. Furthermore, the carbon concentrations did not significantly differ by DC, whereas the nitrogen concentration significantly increased and the C/N ratio decreased. The respiration rate of L. kaempferi CWD increased significantly up to DC IV, but for P. rigida it increased to DC II and then unchanged for DC II-IV. Accordingly, except for carbon concentration, all the measured characteristics showed a significant correlation with $R_{CWD}$. Multiple linear regression showed that $WC_{CWD}$ was the most influential factor on $R_{CWD}$. $WC_{CWD}$ affects $R_{CWD}$ by increasing microbial activity and is closely related to complex environmental factors such as temperature and light conditions. Therefore, it is necessary to study their correlation and estimate the time-series pattern of CWD moisture.

Analyze of I-V Characteristics and Amorphous Sturcture by XRD Patterns (XRD 패턴에 의한 비정질구조와 I-V 특성분석)

  • Oh, Teresa
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.7
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    • pp.16-19
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    • 2019
  • A thinner film has superior electrical properties and a better amorphous structure. Amorphous structures can be effective in improving conductivity through a depletion effect. Research is needed on the Schottky contact, where potential barriers are formed, as a way to identify these characteristics. $SiO_2/SnO_2$ thin films were prepared to examine the amorphous structure and Schottky contact, $SiO_2$ thin films were prepared using Ar = 20 sccm. $SnO_2$ thin films were deposited using mixed gas with a flow rate of argon and oxygen at 20 sccm, and $SnO_2$ thin films were added by magnetron sputtering and treated at $100^{\circ}C$ and $150^{\circ}C$. To identify the conditions under which the amorphous structure was constructed, the XRD patterns were investigated and C-V and I-V measurements were taken to make Al electrodes and perform electrical analysis. The depletion layer was formed by the recombination of electrons and holes through the heat treatment process. $SiO_2/SnO_2$ thin films confirmed that the pores were well formed when heat treated at $100^{\circ}C$ and an electric current was applied over the micro area. An amorphous $SiO_2/SnO_2$ thin film with heat treatment at $100^{\circ}C$ showed no reflection at $33^{\circ}\;2{\theta}$ in the XRD pattern, and a reflection at $44^{\circ}2\;{\theta}$. The macroscopic view (-30 V

An Historical and Cultural Analysis on the Eastern and Western Moat (동·서양 해자(垓字)의 역사와 문화적 해석)

  • Jung, Yong-Jo;Sim, Woo-Kyung
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.29 no.1
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    • pp.105-120
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    • 2011
  • A moat is a pond or waterway paved on the outside of a fortress that is one of the facilities to prevent enemy from approaching the fortress wall or classify it as the boundary space, moats had existed in Europe, Asia and the America from ancient times to medieval times. however it is has been disappeared in modem society. In addition, a moat is a great value in historical and cultural sense such as offering a variety of cultural activities and habitats for animals, but unfortunately there is little consideration of its restoration plan. This research is aimed to investigate historical and cultural meaning and significance of moats which had been existing from ancient times to medieval times in the Eastern and Western. For this purpose, this research analyzed concepts and functions in consideration with times and ideological backgrounds of moats in Korea, China, and Japan. Results were as follows: 1. Moats in Korea existed not only in the castle towns of Goguryeo but also in ancient castle towns of Baekje and Silla. Natural moats and artificial moats existed around castles that were built to prevent and disconnect accessibility of enemies In Goryeo Dynasty and Chosun Dynasty, moats were also used as a defensive function. 2. A moat was generally installed by digging in the ground deep and wide at regular intervals from the ramparts, A moat was installed not only around a castle but also in its interiors. Moats outside castles played an important role in stomping the ground hard besides enhancing its defensive power. In addition, water bodies around a facility often discouraged people's access and walls or fences segregated space physically, but a moat with its open space had an alert and defensive means while pertaining its visual characteristics. 3. The moat found at Nagan Eupseong rumor has it that a village officials' strength was extremely tough due to strong energy of the blue dragon[Dongcheon] in Pungsujiri aspects, so such worries could be eliminated by letting the stream of the blue dragon flow in the form of 'S'. 4. The rampart of the Forbidden City of China is 7.9 meters high, and 3,428 meters long in circumference. It was built with 15 layers of bricks which were tamped down after being mixed with glutinous rice and earth, so it is really solid. The moat of the Forbidden City is 52 meters in width and 6 meters in depth, which surrounds the rampart of the Forbidden City, possibly blocking off enemies' approach. 5. Japan moats functioned as waterways due to their location in cities, further, with the arrangement of leisure facilities nearby, such as boating, fishing from boats, and restaurants, it helped relieve city dwellers' stress and functions as a lively city space. 6. Korean moats are smaller in scale than those of the Forbidden City of China, and Edo, and Osaka castles in Japan, Moats were mostly installed to protect royal palaces or castles in the Eastern Asia whereas moats were installed to protect kings, lords, or properties of wealthy people in the west.

Knowledge graph-based knowledge map for efficient expression and inference of associated knowledge (연관지식의 효율적인 표현 및 추론이 가능한 지식그래프 기반 지식지도)

  • Yoo, Keedong
    • Journal of Intelligence and Information Systems
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    • v.27 no.4
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    • pp.49-71
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    • 2021
  • Users who intend to utilize knowledge to actively solve given problems proceed their jobs with cross- and sequential exploration of associated knowledge related each other in terms of certain criteria, such as content relevance. A knowledge map is the diagram or taxonomy overviewing status of currently managed knowledge in a knowledge-base, and supports users' knowledge exploration based on certain relationships between knowledge. A knowledge map, therefore, must be expressed in a networked form by linking related knowledge based on certain types of relationships, and should be implemented by deploying proper technologies or tools specialized in defining and inferring them. To meet this end, this study suggests a methodology for developing the knowledge graph-based knowledge map using the Graph DB known to exhibit proper functionality in expressing and inferring relationships between entities and their relationships stored in a knowledge-base. Procedures of the proposed methodology are modeling graph data, creating nodes, properties, relationships, and composing knowledge networks by combining identified links between knowledge. Among various Graph DBs, the Neo4j is used in this study for its high credibility and applicability through wide and various application cases. To examine the validity of the proposed methodology, a knowledge graph-based knowledge map is implemented deploying the Graph DB, and a performance comparison test is performed, by applying previous research's data to check whether this study's knowledge map can yield the same level of performance as the previous one did. Previous research's case is concerned with building a process-based knowledge map using the ontology technology, which identifies links between related knowledge based on the sequences of tasks producing or being activated by knowledge. In other words, since a task not only is activated by knowledge as an input but also produces knowledge as an output, input and output knowledge are linked as a flow by the task. Also since a business process is composed of affiliated tasks to fulfill the purpose of the process, the knowledge networks within a business process can be concluded by the sequences of the tasks composing the process. Therefore, using the Neo4j, considered process, task, and knowledge as well as the relationships among them are defined as nodes and relationships so that knowledge links can be identified based on the sequences of tasks. The resultant knowledge network by aggregating identified knowledge links is the knowledge map equipping functionality as a knowledge graph, and therefore its performance needs to be tested whether it meets the level of previous research's validation results. The performance test examines two aspects, the correctness of knowledge links and the possibility of inferring new types of knowledge: the former is examined using 7 questions, and the latter is checked by extracting two new-typed knowledge. As a result, the knowledge map constructed through the proposed methodology has showed the same level of performance as the previous one, and processed knowledge definition as well as knowledge relationship inference in a more efficient manner. Furthermore, comparing to the previous research's ontology-based approach, this study's Graph DB-based approach has also showed more beneficial functionality in intensively managing only the knowledge of interest, dynamically defining knowledge and relationships by reflecting various meanings from situations to purposes, agilely inferring knowledge and relationships through Cypher-based query, and easily creating a new relationship by aggregating existing ones, etc. This study's artifacts can be applied to implement the user-friendly function of knowledge exploration reflecting user's cognitive process toward associated knowledge, and can further underpin the development of an intelligent knowledge-base expanding autonomously through the discovery of new knowledge and their relationships by inference. This study, moreover than these, has an instant effect on implementing the networked knowledge map essential to satisfying contemporary users eagerly excavating the way to find proper knowledge to use.

Development of Summer Leaf Vegetable Crop Energy Model for Rooftop Greenhouse (옥상온실에서의 여름철 엽채류 작물에너지 교환 모델 개발)

  • Cho, Jeong-Hwa;Lee, In-Bok;Lee, Sang-Yeon;Kim, Jun-Gyu;Decano, Cristina;Choi, Young-Bae;Lee, Min-Hyung;Jeong, Hyo-Hyeog;Jeong, Deuk-Young
    • Journal of Bio-Environment Control
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    • v.31 no.3
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    • pp.246-254
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    • 2022
  • Domestic facility agriculture grows rapidly, such as modernization and large-scale. And the production scale increases significantly compared to the area, accounting for about 60% of the total agricultural production. Greenhouses require energy input to create an appropriate environment for stable mass production throughout the year, but the energy load per unit area is large because of low insulation properties. Through the rooftop greenhouse, one of the types of urban agriculture, energy that is not discarded or utilized in the building can be used in the rooftop greenhouse. And the cooling and heating load of the building can be reduced through optimal greenhouse operation. Dynamic energy analysis for various environmental conditions should be preceded for efficient operation of rooftop greenhouses, and about 40% of the solar energy introduced in the greenhouse is energy exchange for crops, so it should be considered essential. A major analysis is needed for each sensible heat and latent heat load by leaf surface temperature and evapotranspiration, dominant in energy flow. Therefore, an experiment was conducted in a rooftop greenhouse located at the Korea Institute of Machinery and Materials to analyze the energy exchange according to the growth stage of crops. A micro-meteorological and nutrient solution environment and growth survey were conducted around the crops. Finally, a regression model of leaf temperature and evapotranspiration according to the growth stage of leafy vegetables was developed, and using this, the dynamic energy model of the rooftop greenhouse considering heat transfer between crops and the surrounding air can be analyzed.