• Title/Summary/Keyword: Mass changes

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Study on magnetorheological damper stiffness shift

  • Jafarkarimi, Mohammad H.;Ghorbanirezaei, Shahryar;Hojjat, Yousef;Sabermand, Vahid
    • Smart Structures and Systems
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    • v.25 no.3
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    • pp.279-284
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    • 2020
  • Electrical current is usually used to change the damping force of Magnetorheological Dampers (MRDs). However, changing the electrical current could shift the stiffness of the system, the phenomenon that was not considered carefully. This study aims to evaluate this shift. A typical MRD was designed, optimized, and fabricated to do some accurate and detailed experimental tests to examine the stiffness variation. The damper is equipped with a circulating system to prevent the deposition of particles when it is at rest. Besides that, a vibration setup was developed for the experimental study. It is capable of generating vibration with either constant frequency or frequency sweep and measure the amplitude of vibration. The damper was tested by the vibrating setup, and it was concluded that with a change in electrical current from 0 to 1.4 A, resonant frequency would change from 13.8 Hz to 16 Hz. Considering the unchanging mass of 85.1 kg, the change in resonant frequency translates as a shift in stiffness, which changes from 640 kN/m to 860 kN/m.

Proteome Analysis of Escherichia coli after High-dose Radiation

  • Lim, Sangyong;Lee, Misong;Joe, Minho;Song, Hyunpa;Kim, Dongho
    • Journal of Radiation Industry
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    • v.5 no.1
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    • pp.1-5
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    • 2011
  • Since proteomics can be employed to compare changes in the expression levels of many proteins under particular genetic and environmental conditions, using mass spectrometry to establish radiation stimulon, we performed two-dimensional gel electrophoresis and identified E. coli proteins whose expressions are affected by high dose of ionizing radiation. After exposure to 3 kGy, it was found that 6 proteins involved in carbon and energy metabolism were reduced. Although 4 of 7 protein spots showing a significant increase in expression level were neither identified nor classified, uridine phosphorylase (Udp), superoxide dismutase (SodB), and thioredoxin-dependent thiol peroxidase (Bcp) were proven to be up-regulated after irradiation. This suggests that E. coli subjected to high doses of radiation (3 kGy) may operate a defense system that is able to detoxify reactive oxygen species and stimulate the salvage pathway of nucleotide synthesis to replenish damaged DNA.

A Study on the Hydrostatic Mooring Stability of Submerged Floating Ellipsoidal Habitats

  • Pak, Sang-Wook;Lee, Han-Seok;Park, Jin
    • Journal of Navigation and Port Research
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    • v.43 no.5
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    • pp.328-334
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    • 2019
  • Underwater architecture in providing a comfortable living space underwater is mandated to survive prevailing environmental loads, especially hydrostatic ambient water pressure exerted on the structure of individual habitat hulls at depth and hydrodynamic fluctuation of external forces that perturb the postural equilibrium and mooring stability of the underwater housing system, for which the design including the hull shape and mooring system constraint the responses. In this study, the postural stability of a proposed underwater floating housing system with three vertically connected ellipsoidal-shape habitat hulls of different sizes are theorized and calculated for hydrostatic stability, using MATLAB in the volumetric integration of a hull and the weight of operational loads under assumed scenarios. The assumptions made in the numerical method to estimate the stability of the habitat system include the fixed weight of the hulls, and their adjustable loads within operational limits for the set meteorological oceanic conditions. The purpose of this study was to numerically manipulate a) The buoyancy and b) The adjusted center of mass of the system within the range of designed external and internal load changes, by which the effective mooring system capability and postural equilibrium requirements were argued with the quantitative analysis.

A Study of Relationship between Clothing and Shoes in the 20th Century Fashion (20세기 의복 스타일과 신발의 관계분석)

  • 오현아;배수정
    • Korean Journal of Human Ecology
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    • v.6 no.2
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    • pp.67-81
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    • 2003
  • This study is for analyzing relationship between clothing and shoes design in the 20th century fashion through studying changes of fashion style. At the beginning of the 20th century, the length of skirts became shorten, so that shoes can be shown. For the result of that. shoes has been developed rapidly in its shape, color, material and ornament with having relations with clothes. The 1st World War made fashion to change into economical style. According to that, shoes also changed with regarding its activities and economical efficiency. In the middle of the 20th century. according to the development of mass media. the stars fashion influenced on the trends of clothes and shoes. As young generation. who leads fashion trends, prefer easy and active clothes, shoes also changed into easy style, sneakers were worn widely and platform sole was applied into various shoes. As a result of this study, shoes design was dynamically changed according to fashion style. The study on its functional efficiency is actively studied now however. the study of shoes design is not. When regarding shoes were always worn with clothes, it is impossible to think shoes and clothes are two things. and also I hope the study on relations between clothes and shoes can be more active and consistently implemented.

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A Study on the Change of Heavy Snow Strength by SST in Influence of Continental Polar Air Mass

  • Park, Geon-Young;Ryu, Chan-Su
    • Journal of Integrative Natural Science
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    • v.7 no.1
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    • pp.39-44
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    • 2014
  • The results of the synoptic meteorological analysis showed that when the cold and dry continental high pressure was extended, heavy snow occurred at dawn when the upper atmosphere cooled. In particular, when the continental high pressure was extended and the upper pressure trough passed through, heavy snow occurred due to the convergence region formed in the west coast area, sometimes in the inland of the Honam area. In addition, it was verified that the changes in the humidity coefficients in the upper and lower layers are important data for the determination of the probability, start/end and intensity of heavy snow. However, when the area was influenced by the middle-latitude low pressure, the heavy snow was influenced by the wind in the lower layer (925 hPa and 850 hPa), the equivalent potential temperature, the convergence field, the moisture convergence and the topography. In Case 2010 (30 December 2010), OSTIA had the best numerical simulation with diverse atmospheric conditions, and the maximum difference in the numerically simulated snowfall between NCEP/NCAR SST and OSTIA was 20 cm. Although there was a regional difference in the snowfall according to the difference in the SST, OSTIA and RTG SST numerical tests, it was not as significant as in the previous results. A higher SST led to the numerical simulation of larger snowfall, and the difference was greatest near Buan in the west coast area.

An Experimental Study on the Effects of Contact Angle on a Falling Liquid Film (접촉각이 유하액막 특성에 미치는 영향에 관한 실험적 연구)

  • Kim, Kyung-Hee;Kang, Byung-Ha;Lee, Dae-Young
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.18 no.11
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    • pp.867-873
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    • 2006
  • Vertical falling liquid film is extensively used in heat and mass transfer processes of many applications, such as evaporative coolers, cooling towers, and absorption chillers. In such cases, it is required that the falling film spreads widely in the surface forming thin liquid film to enlarge contact surface. An addition of surface active agent to a falling liquid film or hydrophilic surface treatment affects the fluid physical properties of the film. Surfactant addition not only decreases contact angle between the liquid and solid surface but also changes the surface from hydrophobicity to hydrophilicity. In this study, the effects of contact angle on falling film characteristics over a vertical surface have been investigated experimentally. The contact angle is varied either by an addition of surfactant to the liquid or by hydrophilic surface treatment. It is found that the wetted area is increased and film thickness is decreased by the hydrophilic treatment as compared with those of other surfaces. With this hydrophilic treatment, the falling liquid film spreads out widely in the surface. As surfactant concentration is increased, wetted area is also increased and the film thickness is substantially decreased.

Green Entrepreneurship: A Study for Developing Eco-Tourism in Indonesia

  • RAHMAWATI, Rahmawati;SUPRAPTI, Anastasia Riani;PINTA, Sarah Rum Handayani;SUDIRA, Putu
    • The Journal of Asian Finance, Economics and Business
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    • v.8 no.5
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    • pp.143-150
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    • 2021
  • This study aims to determine (1) the inhibiting factors and solutions in the development of eco-tourism, and (2) how green entrepreneurship can be used for eco-tourism development. The increasing issue of global warming is pushing awareness of environmental preservation. This condition changes the people's paradigm in traveling from the concept of mass-tourism to the concept of eco-tourism. The development of eco-tourism has consequences for entrepreneurial activities which is known as green entrepreneurship. This study is applied research conducted in East Lombok, one of the regions in Indonesia. The sampling technique used is purposive sampling covering a total of 34 informants. Data collection methods are carried out through interviews, observation, and documentation studies. Based on the data analysis, the findings of this study show that (a) inhibiting factors of eco-tourism development are limitation of eco-tourism knowledge, lack of awareness in environmental preservation, and absence of supporting government policy; and (b) solution for eco-tourism development discovered in this research is divided into five factors i.e., condition, demand, related industry and support, strategy, government. Besides, for applying the green entrepreneurship model i.e., developing the spirit of green entrepreneurship, training in making products and services that are environmentally friendly is needed.

Post Covid-19, Directions and Challenges of Agri-food Distribution (코로나 이후(Post Covid-19) 농식품유통의 방향과 과제 - 전북지역 통합마케팅조직을 중심으로 -)

  • Back, Seoung-Woo;Kim, Su-Hyeon
    • Korean Journal of Organic Agriculture
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    • v.29 no.1
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    • pp.1-23
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    • 2021
  • The form of agri-food transaction has taken a rapid change from the existing method since Covid-19. In response to changes in the market environment such as Covid-19, the integrated marketing organization in Jeollabuk-do was diagnosed from the point of view of innovation, and the future direction was examined. In order to improve the distribution structure of the production area, an integrated marketing organization was fostered, and both quantitative and qualitative growth were brought about. However, some regions still lack willingness to participate and lack of expertise. In particular, there is no infrastructure and strategy to prepare for the increase in non-face-to-face transactions post Covid-19. Online transactions also require economies of scale, so non-face-to-face transaction capabilities must be reinforced by adding a separate organization and experts in charge of online transaction functions within the integrated marketing organization. In the future, online sales are highly likely to expand not only to transactions between producers and individual consumers (C to C), but also to mass consumer (B to B) transactions. It will be an opportunity. In addition, it is necessary to efficiently use production area distribution facilities such as sorting and packaging. Since the non-contact transaction method will increase after Corona 19, it is necessary to strengthen marketing capabilities such as expansion of utilization rate, order placement, settlement, and customer management, and reorganization of specialized organizations.

Air Quality Changes in a Museum Damaged by a Tsunami - Whale and Sea Museum, Iwate, Japan -

  • MATSUI, Toshiya;KAWASAKI, Emi;Huttmann, Imme
    • Journal of Conservation Science
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    • v.35 no.1
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    • pp.51-60
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    • 2019
  • This paper provides quantitative data that describes the evolution of the air quality in the Whale and Sea Museum, located in the Iwate prefecture, collected after the 2011 Great East Japan Earthquake and tsunami. The museum was damaged significantly by the disaster, and restoration works continued for over six years. The air quality in the temporary storage facility and museum was monitored during the rehabilitation process. Evaluation of air quality is carried out by gas chromatography- mass spectrometry, ion chromatography and high-performance liquid chromatography. The results showed that the characteristics of the chemical components differed depending on the measurement locations inside the building. The museum atmosphere tended to be alkaline as the airtightness increased because of the maintenance works at the entrance. It was also determined that it was necessary to study the intake/exhaust routes and to clean them according to the contamination degree. In Japan, there are recommended museum air quality standards for acetic acid, formic acid, alkali, and aldehydes. The results indicated that these standards should not be used as a reference for damaged museums. Furthermore, at the temporary storage facilities for to store the collections during the rehabilitation of the museum, solvents such as ethyl benzene, toluene, and xylene are initially abundant, although they can be reduced by ventilation, while other components such as 2E1H was confirmed in this case are likely to remain.

Surgical Treatment of Chronic Lateral Ankle Instability: Repair versus Reconstruction (만성 족관절 외측 불안정성의 수술적 치료: 봉합술과 재건술의 비교)

  • Kim, Keun Soo;Park, Young Uk
    • Journal of Korean Foot and Ankle Society
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    • v.23 no.1
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    • pp.1-5
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    • 2019
  • Surgical treatment to restore stability in the ankle and hindfoot and prevent further degenerative changes may be necessary in cases in which conservative treatment has failed. Anatomical direct repair using native ligament remnants with or without reinforcement of the inferior retinaculum is the so-called gold standard operative strategy for the treatment of lateral ankle instability. Non-anatomical lateral ligament reconstruction typically involves the use of the adjacent peroneus brevis tendon and applies only those with poor-quality ligaments. On the other hand, anatomic reconstruction and anatomic repair provide better functional outcomes after the surgical treatment of chronic ankle instability patients compared to a non-anatomic reconstruction. Anatomical reconstruction using an autograft or allograft applies to patients with insufficient ligament remnants to fashion direct repair, failed previous lateral ankle repair, high body mass index, or generalized ligamentous laxity. These procedures can provide good-to-excellent short-term outcomes. Arthroscopic ligament repair is becoming increasingly popular because it is minimally invasive. Good-to-excellent clinical outcomes have been reported after short and long-term follow-up, despite the relatively large number of complications, including nerve damage, reported following the procedure. Therefore, further investigation will be needed before widespread adoption is advocated.