• Title/Summary/Keyword: Turning Characteristics

Search Result 506, Processing Time 0.03 seconds

Investigation on ground displacements induced by excavation of overlapping twin shield tunnels

  • Qi, Weiqiang;Yang, Zhiyong;Jiang, Yusheng;Yang, Xing;Shao, Xiaokang;An, Hongbin
    • Geomechanics and Engineering
    • /
    • v.28 no.5
    • /
    • pp.531-546
    • /
    • 2022
  • Ground displacements caused by the construction of overlapping twin shield tunnels with small turning radius are complex, especially under special geological conditions of construction. To investigate the ground displacements caused due to shield machines in the unique calcareous sand layers in Israel for the first time and determine the main factors affecting the ground displacements, field monitoring, laboratory geological analysis, theoretical calculations, and parameter studies were adopted. By using rod extensometers, inclinometers, total stations, and automatic segment-displacement monitors, subsurface tunneling-induced displacement, surface settlement, and displacement of the down-track tunnel segments caused by the construction of an up-track tunnel were analyzed. The up-track tunnel and the down-track tunnel pass through different stratum, resulting in different construction parameters and ground displacements. The laws of variation of thrust and torque, soil pressure in the chamber, excavated soil quantity, synchronous grouting pressure, and grout volume of the two tunnels from parallel to fully overlapping orientations were compared. The thrust and torque of the shield in the fine sand are larger than those in the Kurkar layer, and the grouting amount in fine sand is unstable. According to fuzzy statistics and Gaussian curve fitting of the shield tunneling speed, the tunneling speed in the Kurkar stratum is twice that in the fine-sand stratum.

Identification and Characterization of Diplodia parva and Diplodia crataegicola Causing Black Rot of Chinese Quince

  • Sungmun Kwon;Jungyeon Kim;Younmi Lee;Kotnala Balaraju;Yongho Jeon
    • The Plant Pathology Journal
    • /
    • v.39 no.3
    • /
    • pp.275-289
    • /
    • 2023
  • Fungal isolates from infected Chinese quince trees were found to cause black rot in Yeongcheon, Gyeongsangbuk Province, Korea. The quince leaves withered and turned reddish-brown and fruits underwent black mummification. To elucidate the cause of these symptoms, the pathogen was isolated from infected leaf and fruit tissues on potato dextrose agar and Levan media. Several fungal colonies forming a fluffy white or dark gray mycelium and two types of fungi forming an aerial white mycelium, growing widely at the edges, were isolated. Microscopic observations, investigation of fungal growth characteristics on various media, and molecular identification using an internal transcribed spacer, β-tubulin, and translation elongation factor 1-α genes were performed. The fungal pathogens were identified as Diplodia parva and Diplodia crataegicola. Pathogenicity tests revealed that the pathogen-inoculated fruits exhibited a layered pattern, turning brown rotting; leaves showed circular brown necrotic lesions. The developed symptoms were similar to those observed in the field. Fungal pathogens were reisolated to fulfill Koch's postulates. Apples were inoculated with fungal pathogens to investigate the host range. Strong pathogenicity was evident in the fruits, with browning and rotting symptoms 3 days after inoculation. To determine pathogen control, a fungicidal sensitivity test was conducted using four registered fungicides. Thiophanate-methyl, propineb, and tebuconazole inhibited the mycelial growth of pathogens. To the best of our knowledge, this is the first report on the isolation and identification of the fungal pathogens D. parva and D. crataegicola from infected fruits and leaves of Chinese quince, causing black rot disease in Korea.

Analysis of Navigation Error According to Rotational Motions of Rotational Inertial Navigation for Designing Optimal Rotation Sequence (최적 회전 절차 설계를 위한 회전형 관성항법장치의 회전 동작별 항법 오차 분석)

  • Jae-Hyuck Cha;Chan-Gook Park;Seong-Yun Cho;Min-Su Jo;Chan-Ju Park
    • The Journal of the Korea institute of electronic communication sciences
    • /
    • v.19 no.2
    • /
    • pp.445-452
    • /
    • 2024
  • This paper analyzes the navigation error for each rotational motion in order to design an optimal rotation sequence, which is a key technology in the rotational inertial navigation. Rotational inertial navigation system is designed to cancel out navigation errors caused by inertial sensor errors by periodically rotating the inertial measurement unit. A properly sequenced rotational motion cancels out the maximum amount of navigation error and is known as an optimal rotation sequence. To design such an optimal turning procedure, this paper identifies the feasible rotational motions that can be implemented in a rotational inertial navigation system and analyzes the navigation error introduced by each rotational motion. In addition, by analyzing the characteristics of the navigation error generated during a rotation sequence in combination, this paper presents the conditions for designing an optimal rotation sequence.

Comparison study between recovered carbon black and commercial carbon black filled epoxy conductive materials

  • Huai M. Ooi;Pei L. Teh;Cheow K. Yeoh;Wee C. Wong;Chong H. Yew;Xue Y. Lim;Kai K. Yeoh;Nor A. Abdul Rahim;Chun H. Voon
    • Advances in materials Research
    • /
    • v.13 no.3
    • /
    • pp.221-232
    • /
    • 2024
  • Waste tire management and recycling have grown to be significant issues because they bring up a global environmental concern. Thus, turning recycled waste tires into useful products may help tackle the environmental issue. This research aims to study and compare the effect of recycled carbon black (rCB) and commercial carbon black (CB) at certain 15 vol. % of filler loading on the mechanical, thermal, morphology and electrical properties of epoxy/CB composites. For this project, epoxy resin, diethyltoluenediamine (DETDA), recovered carbon black (rCB) and commercial carbon black (CB) graded N330, N550, N660 and N774 were mixed and compared accordingly to the formulation determined. The CB content was dispersed in the epoxy matrix using the mechanical mixing technique. The distribution and dispersion of CB in the epoxy matrix affect the characteristics of the conductive composites. rCB content at 15 vol% was selected at fixed content for comparison purposes due to the optimum value in electrical conductivity results. The flexural strength results followed the sequence of rCB>N774>N660>N550>N330. As for electrical conductivity results, epoxy/N330 exhibited the highest conductivity value, while the others achieved a magnitude of X10-3 due to the highest external surface area of N330. In terms of thermal stability, epoxy/N330 and epoxy/N774 were slightly more stable than epoxy/rCB.

A field investigation on an expansive soil slope supported by a sheet-pile retaining structure

  • Zhen Zhang;Yu-Liang Lin;Hong-Ri Zhang;Bin He;Guo-Lin Yang;Yong-Fu Xu
    • Structural Engineering and Mechanics
    • /
    • v.91 no.3
    • /
    • pp.315-324
    • /
    • 2024
  • An expansive soil in 4970 special railway line in Dangyang City, China, has encountered a series of landslides due to the expansion characteristics of expansive soil over the past 50 years. Thereafter, a sheet-pile retaining structure was adopted to fortify the expansive soil slope after a comprehensive discussion. In order to evaluate the efficacy of engineering measure of sheet-pile retaining structure, the field test was carried out to investigate the lateral pressure and pile bending moment subjected to construction and service conditions, and the local daily rainfall was also recorded. It took more than 500 days to carry out the field investigation, and the general change laws of lateral pressure and pile bending moment versus local daily rainfall were obtained. The results show that the effect of rainfall on the moisture content of backfill behind the wall decreases with depth. The performance of sheet-pile retaining structure is sensitive to the intensity of rainfall. The arching effect is reduced significantly by employing a series of sheet behind piles. The lateral pressure behind the sheet exhibits a single-peak distribution. The turning point of the horizontal swelling pressure distribution is correlated with the self-weight pressure distribution of soil and the variation of soil moisture content. The measured pile bending moment is approximately 44% of the ultimate pile capacity, which indicates that the sheet-pile retaining structure is in a stable service condition with enough safety reserve.

Sensory and Mechanical Characteristics of Fish Patties according to the Addition of Soybean Powder (대두 분말 첨가량에 따른 어육 패티의 관능적.텍스쳐 특성)

  • Choi, Soo-Keun;Kim, Soo-Hee;Kim, Dong-Seok
    • Culinary science and hospitality research
    • /
    • v.15 no.2
    • /
    • pp.84-92
    • /
    • 2009
  • Fish patty is a product spotlighted recently in the application area of functional food because its main ingredients are soybean and fish with various functions which make it highly digestible, tasty, rich with protein and calcium, and with low fat. Thus, in order to optimize fish patties, this study analyzed their water content, colors, texture and sensory characteristics according to the addition of soybean powder. As a result, water content and lightness decreased with the increase of the addition of soybean powder while hardness, elasticity, chewiness, and gumminess increased with the increase of the addition of soybean powder. Among sensory characteristics, taste, chewiness and texture were highest in S2, and in general evaluation, S2 received the highest score. Thus, S2 was found the most appropriate addition of soybean powder in making fish patties. Based on the results of this study, if fish patties to which soybean powder is added can be used in hamburgers and other food products for the diversity, functionality, and high quality of processed food products using soybean and fish, people's appreciation of hamburgers will be changed, and this will bring a new turning point to the consumption of hamburgers. Furthermore, it is believed that the development of healthy patty-type soybean powder products may resolve worries about fast food and quality-related and health-related problems in hamburger patties.

  • PDF

A Study on dress and its Ornaments for farm-music (농악복식(農樂服飾)에 관한 연구(硏究))

  • Suh, Ok-Kyu
    • Journal of the Korean Society of Costume
    • /
    • v.12
    • /
    • pp.9-23
    • /
    • 1988
  • This study is on the costumes for Korean traditional play, Nong-ak(farm music), and intends to analyze their aesthetic features, laying emphasis on Pilbong Nong-ak, Im sil, Chollanam-do. About its origin there are many kinds of theories; for example, the theory of hoping stability, the theory of it being related with Buddhism, the theory of martial music, etc. Shamanic, Buddhist, and martical fators that support these theories are expressed through flags, bells, drums, Deograe (half-coats), Cheonrips (sang-mo, felf hats), go-kkals(peaked hats), colored lines called 'ga-sa', which are used in Nong-ak. The characteristic of the costumes used in Pilbong Nong-ak is that it keeps its conservativeness and the costumes of its members are various and splendid. For example, leader groups' black half coats, Changbu's and Hwa-dong's red and bule over coats are remarkable. Particpants wear gok-kal or cheonrip, trousers and half coats which are the basic costumes of Korean Hanbok, and wear blak half coats or blue vests and put blue, red, and yellow lines around them. The colors and knotting methods of those lines in this region are the same with those of chollawoo-do and Kyongi province, but different form those of Kongwon and Kyong-sang province using green, red, and yellow colors. This comparison of colors shows each region's preference of peculiar colors and those colors coincide with colors used in flags. The research on the aesthetic characteristics of Nong-ak clothes through each region's clothes tells us that these can be linear clothes which have expressiveness as stage clothes used in Madangori, the play which is performed in the field, and modern spatial formativeness. Those characteristics are as follows; 1. The expressions of a rhythmical and daring round line by turning a long line of sang-mo. 2. Various rhythms according to the attaching methods. 3. The expressions of thick, simple, and daring color lines. 4. Natural beauty of materials. 5. The popular simplicity and non-technicality 6. The beauty of five-direction colors, Oriental ideal colors Consequently in this study our national consciousness of beauty are examined through clothes. It is suggested that the aesthetic characteristics of Nong-ak clothes and ornaments should be effectively expressed, for this purpose. interests in participants' clothes should be increased in order to prevent the confusion of each region's features. Also it is necessary to improve color lines, their length, width, and knotting methods, and beautify instrument. Finally this study intends to bring the reappraisal about the art of Nong-ak clothes and its re-establishment in view of modern aesthetic consciousness.

  • PDF

Culture characteristics and genetic relationship of morel mushroom (Morchella spp.) isolates from Korea and other countries (곰보버섯 (Morchella spp.) 수집균주의 배양적특성 및 유전적 유연관계)

  • Min, Gyeong-Jin;Park, Hye-sung;Lee, Eun-ji;Lee, Chan-Jung
    • Journal of Mushroom
    • /
    • v.18 no.1
    • /
    • pp.100-106
    • /
    • 2020
  • Eight morel mushroom species were collected from Korea and other countries. The culture characteristics, genetic relationships, and beta-glucan content of the strains were analyzed. The mycelia of Morchella species exhibited optimal growth when cultured in dark at 25 ℃ in media with pH 7. The mycelia had a distinctive mycelial scent and characteristically changed color, being white initially, and then turning dark yellow to dark brown as it grew. The mycelia were classified into five types based on morphology. The isolates were identified as Morchella conica, two M. sextelata, M. importuna, M. esculenta, and three M. crassipes, based on ITS-rDNA sequences. PCR polymorphisms were variably produced within Morchella spp. using Universal Fungal Fingerprinting Primers (UFPF) and classified into four groups at the intra and inter species level. The strains, KMCC04971 and KMCC04407, showed the same banding pattern as M. conica and M. sextelata, respectively; however, these results were different from those of ITS analysis. Glucan content analysis by strain showed that the KMCC 04973 strain of M. importuna had the highest alpha- and beta-glucan content, at 16.4 g and 33.1 g per 100 g, respectively.

The Relationship between the Behavioral Characteristics of Elderly and Fatal Pedestrian Accidents (고령보행자의 행동특성과 보행사망사고의 관계)

  • Ju Seok Oh;In Seok Kim;Soon Chul Lee
    • Korean Journal of Culture and Social Issue
    • /
    • v.16 no.1
    • /
    • pp.1-18
    • /
    • 2010
  • This study examines the characteristics of traffic accidents involving elderly pedestrians by analyzing relevant data vis-à-vis fatal pedestrian accidents and proposes solutions to reduce such accidents. We analyzed 3,853 cases of fatal accidents involving elderly pedestrians and 1,786 cases involving younger pedestrian (these cases reflect accidents that occurred from 2005 to 2008). The results show that accidents involving the elderly occur more frequently in rural areas than urban areas, especially in autumn; this condition applies even in situations where the elderly exhibit compensation behaviors such as walking on safer roads. We found that elderly pedestrians exhibit a defective behavior in crossing roads, especially in complicated road conditions where intersections and turning/reversing vehicles represent a menacing threat. These characteristics could be explained by the degenerated physical/mental ability of the elderly and by psychological factors such as reduced level of self-confidence.

  • PDF

A study on Female user's in automobiles design -focusing on inter design of automobiles (자동차디자인에 있어서 여성유저에 관한연구 - 실내편의장치 디자인을 중심으로 -)

  • Park, Eok-Chul;Yoon, Myung-Han
    • Archives of design research
    • /
    • v.19 no.5 s.67
    • /
    • pp.363-372
    • /
    • 2006
  • The aim of this study is to shed light on the importance of female drivers, study their characteristics and needs, and create automobile designs in accordance with the study. The power of female consumers is greatly increasing in a modern society, To the extent that women became the core consumers. Companies are now turning their attention to female consumers in order to survive the fierce competition in the saturated markets. Moreover, it is becoming imperative for companies to actively develop products and services in female perspectives to meet the diversified needs of consumers. It is forecasted that vigorous research, analysis and understanding of the unique culture of women will be increasingly important now that women are emerging as core consumers. Only the companies that makes such efforts consistently can dominate the market. The automobile industry is not an exception. The world's major automobile companies including Volvo and Ford Motor Co. are keenly focusing on automobile exterior and interior designs for women. Korean companies are also designing cars that cater to women, starting with Lanos and Juliet of Daewoo Motors in 1998, yet specific and systematic research on the subject has not been made. This study aims to emphasize the power of female users, make a research and analysis on their needs and characteristics, and suggest car interior designs that cater to them.

  • PDF