• Title/Summary/Keyword: Science box

Search Result 1,419, Processing Time 0.033 seconds

Uplift Bearing Capacity of Spiral Steel Peg for the Single Span Greenhouse (온실용 나선철항의 인발저항력 검토)

  • Lee, Bong Guk;Yun, Sung Wook;Choi, Man Kwon;Lee, Si Young;Moon, Sung Dong;Yu, Chan;Yoon, Yong Cheol
    • Journal of Bio-Environment Control
    • /
    • v.23 no.2
    • /
    • pp.109-115
    • /
    • 2014
  • This study examined the uplift bearing capacity of spiral steel pegs according to the degree of soil compaction and embedded depth in a small-scaled lab test. As a result, their uplift bearing capacity increased according to the degree of soil compaction and embedded depth. The uplift bearing capacity under the ground condition of 85% compaction rate especially recorded 48.9 kgf, 57.9 kgf, 86.2 kgf and 116.6 kgf at embedded depth of 25 cm, 30 cm, 35 cm and 40 cm, respectively, being considerably higher than under other ground conditions. There were huge differences in the uplift bearing capacity of spiral steel pegs according to the compaction conditions of ground. Their maximum uplift bearing capacity was 116.6 kgf under the ground condition of 85% compaction rate and at embedded depth of 40 cm, and it is very high considering the data of spiral steel pegs. It is thus estimated that wind damage can be effectively reduced by careful maintenance of ground condition surrounding spiral steel pegs. In addition, spiral steel pegs will be able to make a contribution to greenhouse structural stability if proper installation methods are provided including the number and interval according to the types of greenhouse as well as fixation of plastic film. The findings of the study indicate that the optimal effects of spiral steel pegs for greenhouse can be achieved at embedded depth of more than 35cm and compaction degree of more than 85%. The relative density of the model ground in the test was 67% at compaction rate of 85%.

Overview of Real-time Visibility System for Food (Livestock Products) Transportation Systems on HACCP Application and Systematization (축산물 유통단계의 HACCP 적용과 체계화를 위한 실시간 관제시스템에 대한 현황)

  • Kim, Hyoun-Wook;Lee, Joo-Yeon;Hong, Wan-Soo;Hwang, Sun-Min;Lee, Victor;Rhim, Seong-Ryul;Paik, Hyun-Dong
    • Food Science of Animal Resources
    • /
    • v.30 no.6
    • /
    • pp.896-904
    • /
    • 2010
  • HACCP is a scientific and systematic program that identifies specific hazards and gives measurements in order to control them and ensure the safety of foods. Transportation of livestock and its products is one of the vulnerable sectors regarding food safety in Korea, as meats are transported by truck in the form of a carcass or packaged meat in a box. HACCP application and its acceleration of distribution, in particular transportation, are regarded as important to providing consumers with ultimately safe livestock products. To achieve this goal, practical tools for HACCP application should be developed. Supply chain management (SCM) is a holistic and strategic approach to demand, operations, procurement, and logistics process management. SCM has been beneficially applied to several industries, notably in vehicle manufacture and the retail trade. HACCP-based real-time visibility system using wireless application (WAP) of the livestock distribution is centralized management system that enables control of temperature and HACCP management in real-time for livestock transportation. Therefore, the application of HACCP to livestock distribution (transportation, storage, and sale) can be activated. Using this system, HACCP management can be made easier, and distribution of safe livestock products can be achieved.

Optimum Packaging Design of Packaging Tray and Cushion Pad of Korean Pears for Exporting using FEA Simulation (FEA 시뮬레이션 기법을 이용한 수출용 한국 배 포장 트레이 및 완충패드 최적 포장설계)

  • Choi, Dong-Soo;Son, Jae-Yong;Kim, Jin-Se;Kim, Yong-Hoon;Park, Chun-Wan;Jung, Hyun-Mo;Hwang, Sung-Wook
    • Journal of the Korean Society of Industry Convergence
    • /
    • v.23 no.5
    • /
    • pp.843-852
    • /
    • 2020
  • Among the many packaging materials used in cushion packaging, there is a lack of optimum design for packaging trays and cushion pads used in pear packaging for export and domestic distribution. It causes over-packaging due to excessive material input, and can be solved by applying various parameters needed to optimize the design of the packaging tray and cushion pad considering the packaging material and the number of pears in the box. In the case of a cushion pad for pears, the economic efficiency of material and thickness should be considered. Therefore, it is possible to design a packaging tray and cushion pad depending on eco-friendly packaging materials (PLA, PET) used by applying appropriate design parameters. The static characteristics of the materials used for the packaging of pears were analyzed using FEA (finite element analysis) simulation technique to derive the optimal design parameters. In this study, we analyzed the contact stress and deformation of PET, PLA tray (0.1, 0.5 1.0, 1.5 and 2 mm) and PET foam (2.0, 3 .0 and 4.0 mm) with pears to derive appropriate cushion packaging design factors. The contact stress between the pear and PET foam pad placed on PLA, PET trays were simulated by FEA considering the bioyield strength (192.54±28 kPa) of the pears and safety factor (5) of packaging design, which is the criterion of damage to the pears. For the combination of PET tray and PET foam buffer pad, the thickness of the PET foam is at least 3 mm, the thickness of the PET foam is at least 1.0 mm, the thickness of the foam is at least 2 mm, and if the thickness of the PET tray is at least 1.5 mm, the thickness of the foam is at least 1 mm, suitable for the packaging design. In addition, for the combination of PLA tray and PET foam pad, the thickness of the PET foam was not less than 2 mm if the thickness of the PLA tray was 0.5 mm, and 1 mm or more if the thickness of the PLA tray was not less than 1.0 mm, the thickness of the PET foam was suitable for the packaging design.

Physical Modeling of Horizontal Force on the Inland Vertical Structure by Tsunami-like Waves (육상의 직립구조물에 미치는 지진 해일에 의한 수평 파력 및 파압에 대한 수리모형실험)

  • Park, Hyongsu;Cox, Daniel;Shin, Sungwon
    • Journal of Korean Society of Coastal and Ocean Engineers
    • /
    • v.29 no.6
    • /
    • pp.363-368
    • /
    • 2017
  • The tsunami flood the coastal cities and damage the land structures. The study on wave pressure and force on land structures is one of the important factors in designing the stability of inland structures. In this study, two - dimensional wave flume tests on the horizontal wave force and pressure of tsunamis on a simplified box-type structure was conducted. Vertical distribution and wave power of horizontal wave pressure over time were measured by pressure sensors and force transducer. Also, those were measured from the different wave breaking types. The vertical distribution of horizontal wave pressure was uniform at the moment when the horizontal wave force to the structure was maximum under the breaking wave condition. A surf similarity parameter was employed in order to figure out the relationship between the maximum horizontal wave force on the structure as a function of various incident wave conditions. As a result, the non - dimensionalized horizontal wave force tends to decrease exponentially as the surf similarity parameter increases.

A Study on the Reorganization of Design by means of a Theme and a Style -for the Establishment of the Identity of Product Design- (테마와 스타일에 의한 디자인의 범주화 연구 -제품디자인의 정체성 확립을 위하여-)

  • 신완식
    • Archives of design research
    • /
    • v.16 no.3
    • /
    • pp.111-122
    • /
    • 2003
  • We must not consider a culture as means of economy. Specially, it is not possible that is supposed to incorporate a cultural identity in a shape of product, but also international competitiveness can not be raised by it. Because an identify is based on the system of symbol such as language, it can be understood only in a same cultural area. While, the value-in-use of technology can be accepted universally as a formative language of international style. Therefore, the competitiveness of design will say as a special quality that can be acquired in connection with technology. For instance, that Korean mobile telephone could be recognized worldwide is not because it has the Koreanized shape but has a high technology. The public have only a superficial understanding about design. Because that is limited in the visual aspect of product, so called 'the pretty design', which exclude the value-in-use and the organic correlation of form and function in general, it may be a cause of socio-ethical dysfunction. It is providing an elbowroom for making a mistake that can regard the product design as an artistic experiment and try to raise the international competitiveness simply with the visual aspect. And the distorted understanding about design has been diffused rapidly owing to spread of black box products because the over-designed shape is known to the public as a proper result of designing. That reorganize the design category will do as a starting point that can get rid of such a misunderstanding, and do to achieve an ideological role of design for human and society. And it will be a warning to the moral slackening that is due to regarding a style as means of competitiveness and the blindness due to thinking culture as means of economy, and we may expect to offer a basic understanding about design which can prevent products from being visualized.

  • PDF

Gas Sensing Characteristics of $SnO_{2}$ added with $TiO_{2},\;Pd,\;Pt$ and in for Trimethylamine Gas (Trimethylamine Gas 측정을 위한 $TiO_{2},\;Pd,\;Pt$ 및 In이 첨가된 $SnO_{2}$가스 센서의 특성)

  • Lee, Chang-Seop;Jung, Soon-Boon;Jun, Jae-Mok;Lee, In-Sun;Lee, Hyeong-Rag;Park, Young-Ho;Choi, Sung-Woo
    • Journal of the Korean Institute of Gas
    • /
    • v.11 no.1 s.34
    • /
    • pp.29-33
    • /
    • 2007
  • This study investigates the use of $TiO_{2},\;Pd,\;Pt$, and In which greatly improves a sensitivity to trimethylamine gas. The metal-$SnO_{2}$ thick films were prepared by screen-printing method onto $Al_{2}O_{3}$ substrates with platinum electrode. The sensing characteristics were investigated by measuring the electrical resistance of each sensor in a test box as a function of detecting gas concentration. This was then used to detect trimethylamine, dimethylamine, and ammonia vapours within the concentration range of 100-1000ppm. The gas sensing properties of metal-$SnO_{2}$ mixed thick films depended on the content and variety of metal. It was found that sensitivity and selectivity of the films dopped with 1 wt% Pd and 10 wt% $TiO_{2}$ for trimethylamin gas showed the best result at $250^{\circ}C$.

  • PDF

Performance-tests of honeybee queens(Apis mellifera) in Korea (여왕봉(女王蜂)의 능력검정(能力檢定)에 관(關)한 연구(硏究))

  • Choi, Kwang Soo;Park, Hang Kyun;Song, Dou Jun
    • Current Research on Agriculture and Life Sciences
    • /
    • v.7
    • /
    • pp.99-107
    • /
    • 1989
  • The study was conducted to obtain some basic information to establish the system of performance-tests and selection of honeybee queens(Apis mellifera) under Korean circumstances, Colony performances were tested with thirty colonies of Apis mellifera at two apiaries in Taegu, Korea from September, 1988 to August 1989. The results of performance-testing on the colonies are summarized as follows : The colony weight measured before wintering was averaged $23.6{\pm}1.90kg$ and the colony weight was decreased by $2.9{\pm}0.82kg$ in average during winter season. Thirteen colonies were entered in two story hive from thirty single box colonies from April 17 to May 5, 1989 with increase of bee population and, consequently, the ability of enter-supers of the colonies apperared to be low. The ability of collecting pollen was measured to be $14.8{\pm}2.15gr$ per colony during 24 hours in April, and the number of swarm cells was counted $12.5{\pm}3.43$ cells per colony in aveage. Tendency to use propolis appeared to be moderate, and the number of returning foragers for a minute per colony was counted $108.7{\pm}18.31$ bees in average. Brood area was measured $2,464{\pm}628,67cm^2$ per colony in the post nectar flow season of acasia, and 30.8 percent of the colonies appeared to be infected with chalkbrood disease, The amount of honey production was $14.9{\pm}8.49kg$ per colony, which was harvested two times during the main nectar flow season of acasia.

  • PDF

Analysis of Producing of Thermostable Alkaline Protease using Thermoactinomyces sp. E79 (Thermoactinomyces sp. E79를 이용한 내열성 Alkaline 단백질 분해효소 생산:환경인자의 영향)

  • 정상원;박성식;박용철;오태광
    • Microbiology and Biotechnology Letters
    • /
    • v.28 no.3
    • /
    • pp.167-171
    • /
    • 2000
  • Analysis of Production of Thermostable Alkaline Protease using Thermoactinomyces sp. E79. Jung, Sang Won, Sung-Sik Park, Yong-Cheol Park" Tae Kwang Oh2, and Jin-Ho Seo*, Department of Food Science and Technology, Seoul National University, Suwon 441-744, Korea, 1lnterdisciplinary program [or Biochemical Engineering & Biotechnology, Seoul National Univer5it}~ Seoul 151 "7421 Koreal 2Microbial Enzyme RU, Korea Research Institute of Bioscience & Biotechnology, Po. Box 1151 Yusong, Taejon 305"6001 Korea - This research was undertaken to analyze fermentation properties of Thermoactinomyces sp. E79 for production of a thermostable alkaline protease, which is able to specifically hydrolyze defatted soybean meal (DSM) to amino acids. TIle optimum pH for cell growth and protease production was pH 6.7, Thermoactinomyces sp. E79 did not grow at pHlO Among carbon sources tested, soluble starch was the best for protease production, while glucose repressed protease production. Tryptone was found to be the best nitrogen source for cell growth and soytone was good tor protease production. Oxygen transfer rate played an important role in producing thermostable alkaline protease. Ma'<..imum values of 6.58 glL of dry cell weight and 43.0 UJmL of protease activity were obtained in a batch fermentation using a 2.5 L jar fermentor at 1.93 X 102 hr-l of volumetric oxygen transfer coeff'jcient (kLa). Addition of 200 mgIL humic acid to the growth medium resulted in 1.64 times higher protease activity and 1.77 times higher cell growth than the case without humic acid addition.

  • PDF

An Experimental Study on Loll (음의 복원력에 의한 횡경사 실험 연구)

  • You, Su-Yeon;Pag, Chong-Lyong;Jung, Dae-Deug
    • Journal of the Korean Society of Marine Environment & Safety
    • /
    • v.22 no.6
    • /
    • pp.654-659
    • /
    • 2016
  • Recently, the passenger ship 'Sewol' capsized with an abrupt inclination while she was making a small angle alteration. It is very important to fully understand the concepts, causes and relevant corrections for a ship's transverse inclination, which is classified into heel, list and loll. In this study, the concept, development and calculation of loll were well considered and the actual magnitude of the angle of loll was simulated in a box-shaped model-ship experiment. The experimental values and its development according to different values of negative stability were compared with calculated values. In the results, experimental values for the angle of loll coincided closely with calculated values and the model inclined symmetrically on both port and starboard sides indicating an outstanding feature of loll. This study is expected to expand the concept of loll and help in the analysis of capsize incidents with unknown causes. Further experimental research or case studies concerning the risk of inappropriate correction for loll arising from misunderstandings will be needed.

A Study on the Fabrication of Uranium-Cadmium Alloy and its Distillation Behavior (우라늄-카드뮴 합금의 제조 및 증류거동에 대한 연구)

  • Kim, Ji-Yong;Ahn, Do-Hee;Kim, Kwang-Rag;Paek, Seung-Woo;Kim, Si-Hyung
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
    • /
    • v.8 no.4
    • /
    • pp.261-267
    • /
    • 2010
  • The pyrometallurgical nuclear fuel recycle process, called pyroprocessing, has been known as a promising nuclear fuel recycling technology. Pyroprocessing technology is crucial to advanced nuclear systems due to increased nuclear proliferation resistance and economic efficiency. The basic concept of pyroprocessing is group actinide recovery, which enhances the nuclear proliferation resistance significantly. One of the key steps in pyroprocessing is "electrowinning" which recovers group actinides with lanthanide from the spent nuclear fuels. In this study, a vertical cadmium distiller was manufactured. The evaporation rate of pure cadmium in vertical cadmium distiller varied from 12.3 to $40.8g/cm^2/h$ within a temperature range of 773 923 K and pressure below 0.01 torr. Uranium - cadmium alloy was fabricated by electrolysis using liquid cadmium cathode in a high purity argon atmosphere glove box. The distillation behavior of pure cadmium and cadmium in uranium - cadmium alloy was investigated. The distillation behavior of cadmium from this study could be used to develop an actinide recovery process from a liquid cadmium cathode in a cadmium distiller.