Development of pellet-type artificial diet for insect was tried by using a twin screw extruder(TSE). Screws were arranged several times and two reverse screws were equipped on the foreparts of 2 axes of TSE. Pellet-type diet could be produced successfully under conditions of TSE set as the following. , 300 rpm of main motor speed, 228 rpm of feed motor speed, 75㎖/min of running water speed and 5 ㎜ of extrusion diameter. The optimum adding quantity of water to the manufactured diet was 1.2~1.5 times of dry diet. On the rearing results of beet armyworm, Spodoptera exigua and common cutworm, Spodoptera litura with the pellet-type diet, the final survival ratio (emergence rate) of these two species was over than 50%, and so it was concluded that the manufactured pellet-type artificial diet was sufficient dietetically to rear those insects.

High speed naval ships are configured with open shafts The shafts, bearings, and propellers are supported by shaft struts. Proper design of struts involves issues of structural, vibration, and hydrodynamic analysis and design. Strut arm cavitation in high speed occurs because of a misalignment of the strut arm with the local incident flow. Proper selection of the strut section can minimize the generation of cavitation. This paper describes issues in the design struts and notices based on the design of Patrol Craft and Amphibious Ship.

선박의 항행안전의 문제가 중요시됨에 따라 선박조종시뮬레이터를 이용한 운항훈련, 안전성 검토 등이 필요성이 중요하게 인식되고 있다. 또한 추진성능을 향상시킬 목적으로 다양한 선종이 출현되고 있고, 이에 따라 선박조종시뮬레이터의 개발에 있어서 선박의 데이터베이스는 필수적이라고 할 수 있다. 따라서 선종에 따른 수학모델을 각각 선박조종시뮬레이터에 적용시킴으로써 다양한 조종 시뮬레이션을 가능하게 할 수 있다. 본 논문에서는 우수한 추진성능을 목적으로 한 2축2타선박을 대상으로 조종운동 수학모델을 정식화하였다. 구체적으로 항만내에서의 저속시 조종운동을 구현할 수 있는 수학모델에 대해서 검토하였으며, 선체·프로펠러·타의 상호간섭에 대해서도 고려하였다. 또한, 수치시뮬레이션을 수행함으로써 2축2타선박의 기본적인 조종성능을 확인하였다.

Proximal femoral fractures are common in older adults. Zimmer natural nail (ZNN, Cephalomedulary Asia; Zimmer, Warsaw, IN, USA) known as useful in immobilizing the fractures of the proximal femoral fractures, have a critical complications like femoral head perforation and cut through in pelvic bone. We report a case that the femoral head perforation by the hip screw occured within 2 months of the operation, and 8 months after operation, the hip screw is completely separated from the metal body and cut through the pelvis.

This study was conducted to estimate the removal efficiency of algae by a mechanical Screw Brush Cone Filter in a lake. The device used a stainless steel cone-shaped filter with a screw brush. The ability of the developed device to remove algae larger than 20μm in Lake ChaSa, Gwangyang city was tested from August to September 2014. The results show that the removal rates for chlorophyll-a, suspended solids and volatile suspended solids were 44-87%(mean 61%), 35-54%(mean 40%), and 37-46%(mean 43%), respectively. This study also discusses equipment and device operation costs and device application problems, and suggests in situ. solutions to these problems.

The principle of treatment of type 2, 3 odontoid process fracture is controversial. The debate is in regard to which is effective between conservative treatment and surgery. We enrolled 41 patients with type 2, 3 odontoid process fracture from January 2007 to December 2011 at Chosun University Hospital. Patients in Group I (GI) received a halo vest and those in Group II (GII) underwent surgery by ant. screw fixation. The bone fusion was classified according to stable bone union, fibrous union, and unstable non-union. Patients in GI received halo vest for a mean period of 4.9 months and those in GII received a neck collar for a mean period of 3.8 months. Tweleve patients in GI and 17 patients in GII had stable bone union. Three patients in GI and two patients in GII had fibrous union. Five patients in GI and two patients in GII had non-union. The halo vest was a good conservative treatment for type 2, 3 odontoid process fracture : however, low bone fusion rate is a problem in particularly old age. However, ant. screw fixation is a better treatment in regard to short surgical time, short fusion time, and high bone fusion rate.

This study was performed to develop a reinforcing head method for steel pipe piles using screw type bending reinforcement, which can fix piles using nuts, and experimentally prove structural performances. In order to do so, steel pipe pile reinforcing head method test specimen using screw bending iron was produced and implemented to vertical tensile test, vertical compression test, and horizontal loading test. As a result, the test showed that it secured 1.28-3.62 times safety factors that are demanded from the design criteria for highway bridge.

본 연구는 조적조 치장벽체의 신축과 보강공사에 사용될 수 있는 나선형 긴결철물을 사용하여 내부벽체와 긴결된 치장벽체의 전단거동실험을 행하여 이 벽체의 구조적 성능을 검증하고 적절한 시공간격⋅형태 등을 제안하기 위한 실험연구이다. 본 연구를 통해 벽체의 Rocking거동에 있어서는 나선형 긴결철물을 사용한 벽체가 기존 시공법의 벽체보다 동일 간격에서는 우수한 전단저항능력을 나타내며, 간격이 30%정도 증가하여도 유사한 능력을 발휘한다. 짧은 간격에서의 긴결도는 기존 시공법보다 상당히 높음으로 고층건물의 치장벽체로 연와조 조적체의 적용가능성을 높일 수 있을 것으로 판단된다.

Mathematical model of maneuvering motion for a single-screw single-rudder ship is established and several applications to the special situations of maneuvering are attempted. While, the mathematical model for twin-screw twin-rudder ship is not presented so much, because that type of ship is not popular. Lee et al. have examined the characteristics of such ship by captive model tests in 1988, in Japan. This paper proposes new mathematical models for propeller effective wake (1 -Ωp) and effective neutral rudder angle deltaR in the case of twin-screw twin-rudder ship. And some maneuvering motionse are calculated with proposed models and compared with exact simulations.

In recent years, propellers with various blade configurations such as highly skewed propellers are often fitted to ships from the viewpoint of reduction of vibration and noise. In the design of such propellers, design charts based on methodical series tests are to be complemented by theoretical calculations for accurate estimation of propeller open-water characteristics. The author intended to develop a method to estimate propeller open-water characteristics based on Quasi -Vortex - Lattice Method originally developed by Lan for solving planar thin wings, The Quasi - Vortex - Lattice Method has the simplicity and flexibility of Vortex - Lattice Method. Its accuracy is comparable to that of the Vortex - Lattice Method. Converged solution can be obtained with a small number of control points and further, leading edge suction force can be calculated directly. In the present paper, a numerical method to estimate propeller open-water characteristics based on the Quasi - Vortex - Lattice Method is reviewed and its application to marine propellers is described in detail. Comparison of propeller open-water characteristics obtained by the present method with experimental data showed good agreement for a wide variety of propellers including highly skewed propellers.