• Title/Summary/Keyword: Compound bow

Search Result 4, Processing Time 0.017 seconds

Kinematic Analysis of Levering Systems in Compound Bows (컴파운더 보우 지레 시스템의 기구학적 해석)

  • Lee, Yong-Sung;Kim, Hong Seok;Cheong, Seong-Kyun;Choi, Ung-Jae;Kim, Young-Keun;Park, Kyung-Rea;Shin, Ki-Hoon
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.37 no.1
    • /
    • pp.55-60
    • /
    • 2013
  • Compound bows use levering systems consisting of cables and cam pulleys to bend limbs that are much stiffer than those of recurve bows, thus storing more energy while requiring less force for the archer to hold the bow at a fully drawn position. Many patents have thus far been proposed to improve the efficiency and performance of compound bows through empirical methods, whereas only a few analytical methods have been proposed. In this light, this paper presents a method for the kinematic analysis of levering systems in compound bows so that a designer can easily predict the effects of changes in the cam profiles and limb materials.

A Study on the Corrosion Loss of Zinc Anodes of the Underwater Shell Plate (선저 아연판의 부식에 관한 연구)

  • Kim, Min-Suck;Lee, Jong-Mun;Kim, Jong-Hwa;Kang, Il-Kwon;Kim, Dong-Soo
    • Journal of Fisheries and Marine Sciences Education
    • /
    • v.19 no.1
    • /
    • pp.129-136
    • /
    • 2007
  • The component parts of the shell plate of a ship are steel. but the screw propeller or the bow thruster is a compound of bronze, nickel and aluminum. On account of the these different components between metals of the shell plate, the screw propeller and the bow thruster, which are underwater, the shell plate of a ship is corroded by the action of ionization. Authors investigated the corrosion loss of the zinc anodes which were attached to the bottom shell of the training ship Kaya for about two years. The obtained results were as follows:1. In case of the shell plate the difference of the corrosion loss according to port and starboard was almost nothing. But the corrosion loss of the forward part was more than that of the aftward part.2. There was little difference in the corrosion loss between the forward and the aftward part on the bilge keel.3. The corrosion loss of the fore, midship and aft part on the false keel were 24.7%, 22.4% and 23.9% respectively.4. The corrosion loss of the fore and the aft part on the false keel was more than that of the midship part.5. The corrosion loss of the bow thruster was greater than any other parts.6. The nearer the zinc anode to the screw propeller the more the corrosion loss on the stern frame, and the situation was also same as on the rudder.

AN EXPERIMENTAL STUDY ON THE ACCURACY OF INTEROCCLUSAL RECORDING MATERIALS (교합관계 기록 재료의 정확성에 관한 임상적 비교 연구)

  • Park, Hong Yul;Chang, Ik Tae;Kim, Kwang Nam
    • The Journal of Korean Academy of Prosthodontics
    • /
    • v.28 no.2
    • /
    • pp.91-108
    • /
    • 1990
  • The purpose of this study was to compare the maganitude of the discrepancies of the mounting errors in according to the states of dentitions, and to the superoinferior, anteroposterior, and rightleft driecetions. GROUP I. : Fourteen patients 22 to 26 years of age with a full complement of teeth, were used in the study. The criteria fro patient selection were a complete dentition, sparse restorarive treatment, and adequate posterior and anterior occlusan stops. And they had no sign and sympton at TMG area. GROUPII. : Eigth patients 37 to 62 years of age with bilateral free ends. The criteria for patient selection were Kennedy classification class 1 cases, and adequate posterior and anterior stops. And the opposite dentitions were a full complement of teeth. Irreversible hydrocolloid impresiion of each arch was taken of each patient. These were immediatel poured in stone and mounted on a Denar Mark II. Articulator with the arbitrary slidematic face-bow. With hand articulation th e mandibular cast was mounted to the maxillary cast in centric occlusion. Five types of interocclusal records were taken of each patient : (1) aluwax (2) baseplate wax; (3) znic oxide-eugenol pasts; (4) polyether (Ramitec); (5) modeling compound. All measurement of the five selected recording materials were compared with those of the hand-articulated full arch models in centric occlusion or maximum interdigitation. The results were as follows; 1. There were statistical differences in amount of devitation in according to the materials and the states of dentition. The amount of deviation of compound was the largest. 2. There were statistical differences in amount of deviation in complete dentition at all directions. The amount of diviation of compound was the largest. And at the right-left direction the amount of znic oxide-eugenol paste was larger than that of baseplate wax. 3. There was a statistical difference in amount of diviations in partial edentulous dentition at the superoinferior direction. The amount of deviation of compound was larger than that of znic oxide-eugenol paste. 4. There was as statistical difference in amount of deviations in partial edentulous dentition at the right-left direction. The amount of deviation of baseplate wax was larger that tnat of polyether. 5. There was not a statistical difference in amount of diviation in partial edentulous dentition at the anteroposterior direction.

  • PDF