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Biomimetic Analysis on the Spider Silk Apparatus for Designing the Nanofiber-spinning Nozzle (나노섬유 방사노즐 설계를 위한 거미 실크 방적장치의 생체모사 분석)

  • Moon, Myung-Jin;Kim, Hoon;Park, Jong-Gu
    • Applied Microscopy
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    • v.42 no.2
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    • pp.67-76
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    • 2012
  • The biomimetic approach on the cuticular spinning nozzles of the major ampullate silk glands in the golden-web spider Nephila calvata has been attempted using various visualizing techniques of light and electron microscopes to improve the design of spinning nozzle for producing synthetic nanofibers spun from electrospinning apparatus. The major ampullate spigot which has the most effective nozzle system to produce nanofibers for dragline silk with high strength and elasticity is connected via the bullet type spigot on anterior spinneret with flexible terminal segment. The excretory duct which transports the liquid silk feedstock from ampulla to spigot is divided into 3 limbs by loops back on itself to form an S-shape morphology that is bundled in connective tissue. Final diameter of the nanofibers at nozzle was dramatically reduced by gradual narrowing of duct cuticle less than 10 times comparing to its original size of funnel region. Moreover, the funnel has a characteristic cuticular organization with porous microstructure which seems to be related to water removal from feedstock of silk precursors. High magnification electron micrographs also reveal the presence of the spiral grooves on the surface of the cuticular intima near the valve which presumed to reduce friction during rapid flow of liquid silk.

The Effects of 'MEETING WITH SCIENTISTS' Program on the Fifth Graders' Physical Images of Scientists ('과학자와의 만남' 프로그램 적용이 초등학생의 과학자에 대한 신체적 이미지에 미치는 효과)

  • Kim, Sung-Kwan;Jang, Myoung-Duk;Jeong, Jin-Woo
    • Journal of The Korean Association For Science Education
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    • v.22 no.3
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    • pp.490-498
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    • 2002
  • This study investigated the effects of the 'Meeting With Scientists' program on children's stereotypical images of scientist. To do those, 36 children of a fifth grade class participated in the program for one month. The program consisted of two main activities:(l) participating in scientists' lectures and exchanging e-mail with them; and (2) visiting web sites about scientist and science, and exchanging e-mail with scientists at the sites. The results of the study can be summarized as follows: First, after participating in the program, children showed the significant decrease of several stereotypical items, such as facial growth of hair(bald hair beard), symbols of research, and age of the scientist. Second, the most popular source of the images was the visual media at the pretest but the source was changed to the visiting and participating scientist's lecture, and internet at the posttest. The latter items appeared a significant difference between the pretest and the posttest, The results indicate that the program is effective to decrease of children's stereotypical physical image of scientist.

Design Methods for Eccentrically Loaded Bolt Groups for the Single Plate Connections Considering Sloped Edge Distance (편심전단을 받는 단일판접합부의 경사연단거리를 고려한 볼트군의 설계법)

  • Choi, Sun Kyu;Yoo, Jung Han;Park, Jai Woo
    • Journal of Korean Society of Steel Construction
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    • v.26 no.1
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    • pp.43-53
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    • 2014
  • A single plate connection(SPC) consists of a plate welded to the columns and bolts connected to the beam web. The SPC is widely used for a simple shear connection of steel structure because it is easy-to-fabricated, easy-to-installed and economical. The conventional SPC is used for 2 to 12 bolts in a single vertical row. It is designed to limit the plate thickness by bolt diameter to obtain flexible and ductile connections. The design strength for eccentric shear shall be the lesser of the shear strength of bolts or bearing strength of plate and when the design strength is decided by edge distance failure, the results can be very conservative. Although the research on special solution for 'weak-plate/strong-bolt' model with 2 to 4 bolts has been conducted by L. S. Muir, and W. A. Thonton, 2004, study on generalized design procedures did not conduct. This study proposed design procedure for evaluation of the design strength of eccentric shear bolt groups on a single plate connection based on the actual edge distance and the direction of bolt reaction forces by using elastic vector method(EVM) and instantaneous center of rotation method(ICM).

A New Short Stem, Lodging Resistance and High Yielding Peanut Variety "Pungan" (단경 내도복 다수성 땅콩 "풍안")

  • Pae, Suk-Bok;Hwang, Chung-Dong;Lee, Myung-Hee;Ha, Tae-Joung;Han, Sang-Ik;Shim, Kang-Bo;Cheong, Young-Keun;Park, Chang-Hwan;Park, Keum-Yong;Ahn, Jin-Gon
    • Korean Journal of Breeding Science
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    • v.41 no.4
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    • pp.635-639
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    • 2009
  • A new peanut variety "Pungan"(Arachis hypogaea ssp. hypogaea L.) was developed at the Department of Functional Crop, NICS(National Institute of Crop Science), in Milyang in 2008. It was developed from the cross between the high-yielding cultivar "Saedl" and the very short stem cultivar "Satonoka". "Pungan", a Virginia palnt type, has 20 branches with long ellipseshaped large grains. The 100 grain weight was 88 g, 7 g heavier than the check variety Daekwang. This variety is more resistant to late leaf spot and web blotch compared to Daekwang, a check variety. Moreover, it is lodging resistant owing to its short stem. "Pungsan" outyielded the check variety by 16% with 4.67 MT/ha in regional yield trials.

A New Short Stem, Disease Resistance and High Yielding Peanut "Pungsan" (단경 내병 다수성 땅콩 품종 "풍산")

  • Pae, Suk-Bok;Cheong, Young-Keun;Park, Chang-Hwan;Lee, Myung-Hee;Hwang, Chung-Dong;Shim, Kang-Bo;Jung, Chan-Sik;Jung, Churl-Whan;Park, Keum-Yong;Park, Chung-Beam;Choi, Gyu-Hwan;Lee, Jae-Chul;Kim, In-Jae;Kim, Je-Kyu
    • Korean Journal of Breeding Science
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    • v.40 no.2
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    • pp.173-177
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    • 2008
  • A new peanut variety "Pungsan" (Arachis hypogaea ssp. hypogaea L.) was developed at the Yeongnam Agricultural Research Institute, NICS, in Milyang in 2007. It was derived from a cross between a short stem cultivar "Satonoka" and a high-yielding local cultivar "Yecheon". "Pungsan" is the Virginia plant type. It has 18 branches per plant and 40 cm of main stem height. Each pod with long-ellipse shaped large kernel has two grains with light-brown testa and 100 seed weight was 95g in the regional yield trials (RYT). "Pungsan" showed more resistant to web blotch compared with check variety. In the regional yield trials "Pungsan" was outyielded in grain yield to the check variety by 16% with 4.45 MT/ha for grain.

A New Short Stem, Lodging Resistance and High Yielding Peanut "Charmpyeong" (단경 내도복 다수성 땅콩 품종 "참평")

  • Pae, Suk Bok;Cheong, Young-Keun;Shim, Kang-Bo;Hwang, Chung-Dong;Lee, Myung-Hee;Jung, Chan-Sik;Kang, Churl-Whan;Park, Keum-Yong;Park, Chung-Bean;Choi, Gyu-Hwan;Lee, Jae-Chul;Kim, In-Jae;Kim, Je-Kyu
    • Korean Journal of Breeding Science
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    • v.40 no.2
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    • pp.168-172
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    • 2008
  • A new peanut variety "Charmpyeong" (Arachis hypogaea ssp. hypogaea L.) was developed at the Yeongnam Agricultural Research Institute, NICS, in Milyang in 2007. It was developed from the cross between the high-yielding cultivar "Shindaekwang" and the very short stem cultivar "ICGV94216". This Virginia plant typed "Charmpyeong" has 33 cm stem height and 18 branch number Each pod with ellipse-shaped large kernel has two grains with brown testa and 100 seed weight was 88 g in the regional yield trials (RYT). This variety also showed more resistant to web blotch compared with check one. Especially it has resistance to lodging until harvesting owing to short stem. In the regional yield trials "Charmpyeong" was outyielded than check variety by 13% with 4.35 MT/ha for grain.

Reduction of headache intensity and frequency with maxillary stabilization splint therapy in patients with temporomandibular disorders-headache comorbidity: a systematic review and meta-analysis

  • Manrriquez, Salvador L.;Robles, Kenny;Pareek, Kam;Besharati, Alireza;Enciso, Reyes
    • Journal of Dental Anesthesia and Pain Medicine
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    • v.21 no.3
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    • pp.183-205
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    • 2021
  • This systematic review and meta-analysis aimed to analyze the effectiveness of maxillary stabilization splint (SS) therapy to reduce headache (HA) intensity and HA frequency in patients with temporomandibular disorders (TMD)-HA comorbidity. Randomized controlled trials (RCTs) using full-arch coverage, hard resin, and maxillary SS therapy were included. Electronic databases, including Cochrane Library, MEDLINE through PubMed, Web of Science, and EMBASE, were searched. The risk of bias was analyzed based on Cochrane's handbook. The search yielded 247 references up to January 28, 2020. Nine RCTs were included at a high risk of bias. The comparison groups included other splints, counseling, jaw exercises, medications, neurologic treatment, and occlusal equilibration. Four studies reported a statistically significant reduction in HA intensity, and five studies reported significant improvement in HA frequency from baseline at 2-12 months in patients with TMD-HA comorbidity treated with a full-arch hard maxillary SS. HA frequency in tension-type HA (TTH) comorbid with TMD diagnoses of myofascial pain (MFP) or capsulitis/synovitis improved significantly with SS than that with full-arch maxillary non-occluding splint (NOS) in two studies. Comparison groups receiving hard partial-arch maxillary splint nociceptive trigeminal inhibition (NTI) showed statistically significant improvements in HA intensity in patients with mixed TMD phenotypes of MFP and disc displacement comorbid with "general HA." Comparison groups receiving partial-arch maxillary resilient/soft splint (Relax) showed significant improvements in both HA intensity and frequency in patients with HA concomitant with MFP. The meta-analysis showed no statistically significant difference in the improvement of pain intensity at 2-3 months with comparison of the splints (partial-arch soft [Relax], hard [NTI], and full-arch NOS) or splint use compliance at 6-12 months with comparison of the splints (partial-arch Relax and full-arch NOS) versus the SS groups in patients with various TMD-HA comorbidities. In conclusion, although SS therapy showed a statistically significant decrease in HA intensity and HA frequency when reported, the evidence quality was low due to the high bias risk and small sample size. Therefore, further studies are required.

Assessing the Habitat Potential of Eurasian Otter (Lutra lutra) in Cheonggye Stream Utilizing the Habitat Suitability Index (서식지 적합성 지수를 이용한 청계천 수달의 서식지 평가)

  • In-Yoo Kim;Kwang-Hun Choi;Dong-Wook W. Ko
    • Korean Journal of Environment and Ecology
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    • v.37 no.2
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    • pp.140-150
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    • 2023
  • The Eurasian otter (Lutra lutra) is an apex predator of the riparian ecosystem. It is a keystone and an indicator species; consequently, its presence suggests a sustainable water environment. Otter is a keystone species as a predator at the top of the food web in the aquatic environment and an indicator species representing the health of the aquatic environment. Although Eurasian otters disappeared from the Han River urban water system because of anthropogenic activities like habitat destruction, poaching, and environmental pollution in the 1980s, the species were sighted in the Cheonggye Stream, Jungrang Stream, and Seongnae Stream, which are urban sections of the Han River, in 2016 and 2021. Therefore, it is pertinent to assess the habitat potential in the area for conservation and management measures to ensure its permanent presence. However, existing studies on otter habitats focused on natural rivers and reservoirs, and there is a limit to applying them to habitats artificially confined habitats in narrow spaces such as tributaries in urban areas of the Han River. This study selected the Cheonggye Stream, an artificially restored urban stream, to evaluate its potential as a habitat for Eurasian otters in urban water environments using the habitat suitability index (HSI). The HSI was calculated with selected environment attributes, such as the cover, food, and threat, that best describe the L. lutra habitat. According to the results, the confluence area of Seongbuk Stream and Cheonggye Stream and the confluence area of Cheonggye Stream and Jungnang Stream were suitable otter habitats, requiring appropriate conservation efforts. The HSI model suggests a valuable method to assess the habitat quality of Eurasian otters in urban water environments. The study is crucial as it can help rehabilitate the species' populations by identifying and managing potential Eurasian otter habitats in highly urbanized areas of the Han River basin and its tributaries.

Characteristic of Seasonal Dynamics of Planktonic Ciliates at Four Major Ports (Busan, Ulsan, Gwangyang and Incheon), Korea (한국의 4개 주요항만(부산, 울산, 광양, 인천)에 분포하는 섬모충 플랑크톤의 계절동태 특성)

  • Yang, Seung-Woo;Lee, Joon-Baek;Kim, Young-Ok
    • Korean Journal of Environmental Biology
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    • v.36 no.2
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    • pp.217-231
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    • 2018
  • Planktonic ciliates play an important role in the food web of marine ecosystem as well as a bio-indicator for invasive species from ballast waters or from changing flow of ocean currents due to climate changes. This study was carried out to find some evidences for introduction of such invasive species using ciliate plankton in four major international ports of Korea. We surveyed the seasonal species composition of planktonic ciliate to find out the evidence for the invasive species at Busan, Ulsan, Gwangyang and Incheon ports from February 2007 to November 2008. A total of 45 ciliates species, belonging to 15 genera, were identified during the study period: 33 species occurred at Busan, 31 at Gwangyang, 30 at Ulsan, 18 at Incheon. The abundance of naked ciliates ranged from 566 to $65,151cells\;L^{-1}$ and that of tintinnids 10 to $5,973cells\;L^{-1}$. Based on vector species of ciliates reported from Coos Bay in Oregon, 13 vector species of tinitinnids were identified as follows, Eutintinnus lususundae, E. tubulosus, Favella ehrenbergii, F. taraikaensis, Helicostomella subulata, Stenosemella nivalis, Tintinnopsis ampla, T. beroidea, T. cylindrica, T. directa, T. lohmanni, T. radix, T. rapa. All vector species occurred at Gwangyang port. Most tintinnids were mainly neritic species throughout the survey, while warm water species occurred only in short period at Busan, Ulsan and Gwangyang ports that might be affected seasonally by Tsushima warm current.

Quantitative Microbial Risk Assessment Model for Staphylococcus aureus in Kimbab (김밥에서의 Staphylococcus aureus에 대한 정량적 미생물위해평가 모델 개발)

  • Bahk, Gyung-Jin;Oh, Deog-Hwan;Ha, Sang-Do;Park, Ki-Hwan;Joung, Myung-Sub;Chun, Suk-Jo;Park, Jong-Seok;Woo, Gun-Jo;Hong, Chong-Hae
    • Korean Journal of Food Science and Technology
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    • v.37 no.3
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    • pp.484-491
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    • 2005
  • Quantitative microbial risk assessment (QMRA) analyzes potential hazard of microorganisms on public health and offers structured approach to assess risks associated with microorganisms in foods. This paper addresses specific risk management questions associated with Staphylococcus aureus in kimbab and improvement and dissemination of QMRA methodology, QMRA model was developed by constructing four nodes from retail to table pathway. Predictive microbial growth model and survey data were combined with probabilistic modeling to simulate levels of S. aureus in kimbab at time of consumption, Due to lack of dose-response models, final level of S. aureus in kimbeb was used as proxy for potential hazard level, based on which possibility of contamination over this level and consumption level of S. aureus through kimbab were estimated as 30.7% and 3.67 log cfu/g, respectively. Regression sensitivity results showed time-temperature during storage at selling was the most significant factor. These results suggested temperature control under $10^{\circ}C$ was critical control point for kimbab production to prevent growth of S. aureus and showed QMRA was useful for evaluation of factors influencing potential risk and could be applied directly to risk management.