• Title/Summary/Keyword: lever

Search Result 412, Processing Time 0.028 seconds

Small Agricultural Skid-steer Loader Using Belt Clutch Power Transmission (벨트클러치 전동방식의 농업용 소형 스키드 스티어 로더)

  • 김상헌;신범수;정준모;김창식
    • Journal of Biosystems Engineering
    • /
    • v.21 no.2
    • /
    • pp.134-145
    • /
    • 1996
  • Since the skid-steer loader is able to work for excavating, lifting and transporting load even at the narrow space, they are widely used in the regular farm and the livestock farm. The skid-steer loader normally adopts the hydrostatic transmission because the power to move the machine backward and forward should be delivered independently on both sides of wheels. Contrast to the mechanical system such as chain and belt transmissions, however, the hydrostatic transmission is less efficient in the use of energy and more difficult in the maintenance. This study was intended to investigate the feasibility of using triangular-type belt clutch and V-belt transmission for the newly developed skid-steer loader in order to overcome the problems stated in the hydrostatic transmission. In the developed triangular-type belt clutch, the centers of driving, driven and idler sheaves are arranged in the triangular shape in a plane, and V-belts were loaded loosely on three sheaves. The power is transmitted by pressing the idler connected to a lever on the loosened V-belt. Contrast to the normal belt clutch using two sheaves, the newly developed belt clutch has the characteristics of small contact-angle of the driving sheave at no bucket load and increasing contact-angle at the time of power transmission. The results of research can be summarized as follows: 1) The developed triangular-type belt clutch adopted a spring-loaded slackside idler which could transmit more power than a fixed idler could by sacrificing the belt life. The life of V-belt used in the power transmission reached at 500 hours(6 months) when the engine power of 11.8 ㎾ was transmitted. Also, it was feasible to develop the large industrial skid-loader with the V-belt transmission by using the proper set of sheaves. 2) The developed skid-steer loader changed the rotating radius and speed with bucket loads as the conventional skid steer loader did. The rotating speed was 47 deg/s at the maximum bucket load of 2.74 kN when the minimum rotating radius was 1.5m. 3) The power required in turning at the bucket load of 2.74 kN was 4 ㎾ and the slippage of V-belt was less than 1%.

  • PDF

Growth Inhibition of E. coli O157:H7 and Salmonella typhimurium by Lactic Acid Bacteria and Bifidobacteria (젖산균과 비피더스균에 의한 Escherichia coli O157:H7과 Salmonella typhimurium의 생장억제)

  • 김현욱;안영태;신필기
    • Journal of Food Hygiene and Safety
    • /
    • v.12 no.3
    • /
    • pp.181-187
    • /
    • 1997
  • Lactobacillus acidophilus NCFM, Lactobacillus casei YIT 9018, Bifidobacterium longum 8001, and Bifidobacterium longum 8025 at the level of 106 cfu/$m\ell$ were cultured with 104 cfu/$m\ell$ of Escherichia coli O157:H7 KSC 109 or Salmonella typhimurium ATCC14028, in order to verify the effects of lactic acid bacteria and bifidobacteria on the growth of the pathogens. In the mixed culture of lactic acid bacteria with E. coli O157:H7 KSC 109, Growth inhibition and atypical microcolonies of E. coli O157:H7 KSC 109 were observed. The pathogens inoculated grew for 5 hors (pH 5.3), by the time L. acidophilus NCFM reached the exponential growth phase, and then the surviving pathogens were decreased to 101 cfu/$m\ell$ after 35 hours. When L. caseiYIT 9018 was grown with the pathogens, they grew for 10 hours (pH 4.6), by the time L. casei YIT 9018 reached the end of exponential growth phase, and then the surviving pathogens were decreased drastically. Up to the stationary growth phase of lactic acid bacteria, L. acidophilus NCFM exhibited stronger inhibition against the pathogens than L. casei YIT 9018 did, which might be attributed to its faster growth. Likewise bifidobacteria inhibited the growth of the pathogens tested, bifidobaceria was weaker in the inhibitory activity than lactic acid bacteria. When Bifidobacterium longum 8001 was cultured with the pathogens, E. coli O157:H7 KSC 109 was gradually ingibited at the stationary growth phase of bifidobacteria, atypical microcolonies were formed on Levine EMB medium after 48 hours, and Salmonella grew up to 106 dfu/$m\ell$, then was drastically ingibited at the exponential growth phage of Bifidobacterium longum 8001. But when Bifidobacteriuam longum 8025 was cultured with the pathogens, the pathogens grew to the same level of Bifidobacteriuam longum 8025 was cultured with the pathogens, the pathogens grew to the same lever of Bifidobacteriuam longum 8025 after 10 hours, then the surviving pathogens were decreased drastically.

  • PDF

Through Knee Amputation: Technique Modifications and Surgical Outcomes

  • Albino, Frank P.;Seidel, Rachel;Brown, Benjamin J.;Crone, Charles G.;Attinger, Christopher E.
    • Archives of Plastic Surgery
    • /
    • v.41 no.5
    • /
    • pp.562-570
    • /
    • 2014
  • Background Knee disarticulations (KD) are most commonly employed following trauma or tumor resection but represent less than 2% of all lower extremity amputations performed in the United States annually. KDs provide enhanced proprioception, a long lever arm, preservation of adductor muscle insertion, decreased metabolic cost of ambulation, and an end weight-bearing stump. The role for KDs in the setting of arterial insufficiency or overwhelming infection is less clear. The purpose of this study is to describe technique modifications and report surgical outcomes following KDs at a high-volume Limb Salvage Center. Methods A retrospective study of medical records for all patients who underwent a through-knee amputation performed by the senior author (C.E.A.) between 2004 and 2012 was completed. Medical records were reviewed to collect demographic, operative, and postoperative information for each of the patients identified. Results Between 2004 and 2012, 46 through-knee amputations for 41 patients were performed. The mean patient age was 68 and indications for surgery included infection (56%), arterial thrombosis (35%), and trauma (9%). Postoperative complications included superficial cellulitis (13%), soft tissue infection (4%), and flap ischemia (4%) necessitating one case of surgical debridement (4%) and four transfemoral amputations (9%). 9 (22%) patients went on to ambulate. Postoperative ambulation was greatest in the traumatic cohort and for patients less than 50 years of age, P<0.05. Alternatively, diabetes mellitus and infection reduced the likelihood of postoperative ambulation, P<0.01. Conclusions Knee disarticulations are a safe and effective alternative to other lower extremity amputations when clinically feasible. For patient unlikely to ambulate, a through-knee amputation maximizes ease of transfers, promotes mobility by providing a counterbalance, and eliminates the potential for knee flexion contracture with subsequent skin breakdown.

Multi-camera System Calibration with Built-in Relative Orientation Constraints (Part 1) Theoretical Principle

  • Lari, Zahra;Habib, Ayman;Mazaheri, Mehdi;Al-Durgham, Kaleel
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
    • /
    • v.32 no.3
    • /
    • pp.191-204
    • /
    • 2014
  • In recent years, multi-camera systems have been recognized as an affordable alternative for the collection of 3D spatial data from physical surfaces. The collected data can be applied for different mapping(e.g., mobile mapping and mapping inaccessible locations)or metrology applications (e.g., industrial, biomedical, and architectural). In order to fully exploit the potential accuracy of these systems and ensure successful manipulation of the involved cameras, a careful system calibration should be performed prior to the data collection procedure. The calibration of a multi-camera system is accomplished when the individual cameras are calibrated and the geometric relationships among the different system components are defined. In this paper, a new single-step approach is introduced for the calibration of a multi-camera system (i.e., individual camera calibration and estimation of the lever-arm and boresight angles among the system components). In this approach, one of the cameras is set as the reference camera and the system mounting parameters are defined relative to that reference camera. The proposed approach is easy to implement and computationally efficient. The major advantage of this method, when compared to available multi-camera system calibration approaches, is the flexibility of being applied for either directly or indirectly geo-referenced multi-camera systems. The feasibility of the proposed approach is verified through experimental results using real data collected by a newly-developed indirectly geo-referenced multi-camera system.

The Development of the Program Using Virtual Reality Environment to Treat the Stress Disorder after Car Accident (가상현실을 이용한 교통사고 후유장애 치료 프로그램 개발)

  • 김형래;이상호;노주선;김현택;김지혜;고희동
    • Science of Emotion and Sensibility
    • /
    • v.4 no.2
    • /
    • pp.33-38
    • /
    • 2001
  • This analysis has been projected as a preliminary analysis to develop the therapy program for people who is suffering from stress disorder after car accident such as sense of fear or anxiety using virtual reality. The analysis verified the effect of driving scenario which is core technology of stress disorder program and of anxiety reduction training such as relaxation training through clients. The relaxation training has been tested to 8 people; 7 normal and 1 sufferer from car accident presenting them 3 different types of driving scenarios. As a result, relaxation training was effective but, it was not statistically good enough although it showed incensement of uneasiness by each different driving scenario. In spite of normal clients, it is interesting that anxiety lever after relaxation training using VR is lowered, but this result need to verify to client suffering real car accident.

  • PDF

Automatic Control of the Comnbine(I) -Automatic guidance control of the head-feed combine- (콤바인의 자동제어에 관한 연구(I) -자탈형(自脱型) 콤바인의 주행방향제어(走行方向制御)-)

  • Chung, Chang-Joo;Kim, Seong-Ok;Kim, Soo-Sung
    • Journal of Biosystems Engineering
    • /
    • v.13 no.2
    • /
    • pp.38-45
    • /
    • 1988
  • This study was intended to develop the system automatically controlling travel direction of combine by means of sensing paddy rows. The control system was composed of three detecting levers having different length, micro-switch, microcomputer and electro-hydraulic control system. Sensor and control system developed was tested to estimate optimum design values and its actual performance as installed in combine. The computer simulation and performance test at simulated and actual field were conducted to test for possibility of practical use. The results of the study arc summarized. as follows: 1. The travel traces of combine hiving the conventional sensor with 2 levers and the new sensor detecting the slope of paddy rows were compared through computer simulation. Turning frequency of combine having new sensor was fewer than that of conventional sensor, but the rate of turning for the combine with new sensor was much greater than that of conventional sensor. 2. As sensor was established behind the tip of divider, the sensor itself well followed paddy rows but the tip of divider did not, resulting in divider being deviated from paddy rows. It was analyzed that the sensor should be attached closer to the tip of divider to have a better performance of the control system. 3. The greater the length of sensor lever for given location of sensor attachment and combine forward speed, the higher sensitivity of turning in control system. Moreover, increasing combine speed resulted in a worse performance of control system following paddy rows. Consequently, it was necessary that an optimum length of sensor attachment and for the range of combine operational speed. 4. Field test of combine installed with the sensor and electro-hydraulic system developed in this study showed that it may be operated smoothly and well behaved to paddy rows to 4th gear of combine speed which was 59cm/s. Consequently. it was concluded that the combine with the guidance control system developed in this study may be successfully used for paddy combining.

  • PDF

Application and Evaluation of the Sheet Flow Channel for Water Quality Improvement in the Stream (하천 내 수질 개선을 위한 박층류 하도의 적용 및 평가)

  • Lee, Du Han;Kim, Myounghwan;Gu, Jung-Eun;Kim, Won
    • Ecology and Resilient Infrastructure
    • /
    • v.6 no.4
    • /
    • pp.208-216
    • /
    • 2019
  • This study investigated design factors and removal efficiencies of a sheet flow channel as natural type water improvement techniques in the stream. The channel was designed considering the design factors, then constructed and monitored in the test bed of the Osan stream's floodplain. Water lever, velocity, discharge, T-P, T-N, and NO3-N were monitored and the removal efficiencies and design formula were suggested. Overall efficiencies of T-P, T-N, and NO3-N range 10 - 20%, and they show consistent relations with residence times. Minimum velocity requirement is also suggested from the relation of algae conditions and velocities. Relation formula of residence time and removal efficiency will be applicable in the design and operation process of a sheet flow channel.

Phototaxis of Fish (3) - Response of Rock bream and Grass Puffer to the Colored lights - (어류의 주광성에 관한 연구 (3) - 어광의 돌돔과 복섬의 반응 -)

  • 양용림
    • Journal of the Korean Society of Fisheries and Ocean Technology
    • /
    • v.16 no.1
    • /
    • pp.37-42
    • /
    • 1980
  • The purpose of the present study is to find the color induced maximum gathering rate and to observed'the trend of the - gathering rate by using two species of commercial fishes: rock bream, Oplegnathus fasciatus (Temminet et Schlegel) and 'grass puffer, Fugu niphobles (Jordan et Snyder). An experimental tank($360L{\times}50W{\times}55H cm$) was set up in a dark room. An illumination system was attached to the two end of tank to fix horizontal light intensity by co~bination c' one light bulb(20W) and four filters (red, blue, yellow, white) and the five regulating filters in order to fix light intensity. During the experiment water depth was maintained 50 cm lever in the tank. The tank was marked into six longitudinal sections each being 60 em long to observe the distribution of fish. The fish were acclimatized in dark condition for 40 minutes prior to the main experiment. Upon turning on the light, the number of fish in each section was counted 40 times every 30 seconds, and the gathering rates ,were obtain from the average number of fish in each secion. The color induced maximum gathering rate of rock bream appeared to be red, blue yellow and white color orderly.However, that of grass puffer appeared to be blue, white, yellow and red color orderly. Trend of the gathering rate in illumination time showed the remarkable fluctuation in the rock bream and little difference at the two color light sources. However, trend of the gathering rate in illumination time showed the little fluctuation in grass puffer and much difference at the two color light sources.

  • PDF

An Examination of the Minimum Reinforcement Ratio for Reinforced Concrete Flexural Members (철근콘크리트 휨부재의 최소철근비에 대한 고찰)

  • Choi, Seung-Won
    • Journal of the Korea institute for structural maintenance and inspection
    • /
    • v.21 no.6
    • /
    • pp.35-43
    • /
    • 2017
  • The minimum reinforcement ratio is an important design factor to prevent a brittle failure in RC flexural members. A minimum reinforcement ratio is presented by assuming an effective depth of cross-section and moment arm lever in CDC and KHBDC. In this study, it suggests that a rational method for minimum reinforcement ratio is calculated by material model and force equilibrium. As results, a minimum reinforcement ratio using a p-r curve in KHBDC is evaluated about 52~80% of recent design code's value and it induces an economical design. And also, a ductility capacity in case of placing this minimum reinforcement amount is evaluated about 89% of recent design code's value, but ductility in a member is 7 or more, so it has a sufficient ductility capacity. Therefore, it is judged that a minimum reinforcement ratio using p-r curve has a theoretical rationality, safety and economy in a flexural member design.

A Study on the Spatial Composition Characteristics of Elderly Housing facilities in Korea (한국 노인주거시설의 공간계획 특성에 관한 연구)

  • Oh Hye Kyung;Hong Yi Kyung;Him Hyun Jee
    • Journal of Families and Better Life
    • /
    • v.22 no.6 s.72
    • /
    • pp.133-142
    • /
    • 2004
  • The purpose of this study was to investigate the spatial composition characteristics of elderly housing facilities in Korea, in order to refer them in establishing the basic plan for elderly housing in Korea. The case study performed in this study from October 16 to October 31 is based on ten housing facilities for the elderly in KOREA. During the site visits, the interview with the custodians, survey of the space, picture taking and diagram gathering were carried out. The results of this study were as follows; 1. The type of floor plan was classified into ㅁ type, L type, and ㅡ type. And they hadn't an outside space called a garden(courtyard). 2. The kinds of common spaces could be grouped as the space for basic living, for leisure, and for convenient living. Also it was all common that the housing facility had common diningroom laundry room once, and activity room. The type of the common spaces was categorized into three types, the centralized type where the shared space was located at the center of the housing facilities, the distributed type, depending on the degree of separation between common spaces and units, and another each building type. 3. The kinds of units was classified into studio, oneroom, one bedroom and two bedroom. 4. Elevator, safety grab bar, emergency bell, and the door handle of lever or bar type were placed in these facilities.