• Title/Summary/Keyword: Air Pocket

Search Result 79, Processing Time 0.031 seconds

Resonant Frequency Recovery of Resonator for Magnetic Resonant Wireless Power Transfer Inserted into Dielectric Material (유전체에 삽입된 자기공진형 무선전력전송 공진기의 공진주파수 복원에 관한 연구)

  • Kang, Seok Hyon;Jung, Chang Won
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.29 no.12
    • /
    • pp.992-995
    • /
    • 2018
  • The wireless charging of body-embedded medical instruments and wireless power transfer to various inside dielectric-materials is still a future technology that has not yet been achieved. This paper proposes methods for controlling the capacitance of the resonators and installing air pockets on the top and bottom sides of the resonators for optimal design, which considered efficiency and resonant frequency in accordance with the electromagnetic characteristics of the dielectric medium. In future, the results of this research will be utilized as the basic research data to design and restore resonant frequency of resonators embedded in various dielectric environments.

A CLINICAL STUDY OF THE EFFECTS ON THE HEALING PROCESS OF ADMINISTRATION OF THE ZEA MAYS L. AFTER PERIODONTAL SURGERY (치주수술후 Zea Mays L. 투여가 치유과정에 미치는 영향에 대한 임상적 연구)

  • Kwon, Young-Hyuk;Lee, Man-Sup;Yang, Seung-Han;Kim, Young;Park, Joon-Bong
    • Journal of Periodontal and Implant Science
    • /
    • v.24 no.3
    • /
    • pp.649-660
    • /
    • 1994
  • The purpose of this study was to evaluate the effects of administration of Zea Mays L. on the healing process after periodontal surgery as adjuntives. Authors used 3 kinds of different clinical criteria, depth of periodontal pocket by using the Goldman Fox periodontal probe, degree, of tooth mobility by Periotest, and amount of occlusal force with electronic device. In this comparative clinical study, 30 patients who were divided into two group, 15 ZML administrated group and 15 placebo adminstrated group, were participated. All the examined teeth were isolated with gauze and air spray, and measured each clinical critera on the day of before surgery, 1, 2, 4, 8 weeks after surgery. The results were as follows. 1. The changes of the periodontal pocket depth, on the both of Zea Mays L. administrated group and placebo adminstrated group, revealed the decreasing tendency, and it was shown the time dependent tendency. But there was no statistically significant differences between the two group. 2. In the case of tooth mobility, both group showed the highest severe mobility on the 1 week after surgery. It was observed that experimental group had more effects on decreasing the mobility. But there was no statistically significant differences between the two group. 3. In the case of experimental group, the recovery trend of occlusal forces after periodontal surgery on the molar teeth revealed higher than the control group. But there was no statistically significant differences between the two group. In conclusion, Zea Mays L. may play a favorable role in the healing process after periodontal surgery. It was suggested that further study to evaluate the effects of selective administration on the patient who have systemic diseases should be needed.

  • PDF

A Study on the Actual Wearing Conditions of Korean Military Tank Driver's Clothing (전차병복 착용실태에 관한 연구)

  • Kwon, Seo-Yoon;Lim, Chae-Guen;Shin, Dong-Woo;Jung, Hyun-Mi
    • Fashion & Textile Research Journal
    • /
    • v.13 no.4
    • /
    • pp.582-589
    • /
    • 2011
  • The purpose of this study was to investigate problems of design, fitness, suitability for movement, and comfort in current Korean military tank driver's clothing through analysis of actual wearing condition by questionnaire and field evaluation and. to provide basic data for developing a improved design of Korean military tank driver's clothing. The survey was done for 477 military tank driver and the field evaluation was also done for evaluation. The overall satisfaction for design of military tank driver's clothing(3.25) was higher than that for the easiness in wearing and taking off(2.76). The military tank drivers evaluated that current coverall type of clothing is more suitable than two-piece type of clothing. The overall satisfaction for fitness of clothing was as a whole low(2.82~3.09), Especially, the satisfaction for fitness of from front and back rise length was the lowest one. In the satisfaction for clothing materials, the satisfaction for the breathability of material was the lowest, followed by clothing insulation and air permeability. The satisfaction for movement was low in bending waist and raising forward and aside. The part which surveyors think most dissatisfactory was also front and back rise length. The frequency in use of pocket was the highest in chest pocket, followed by waist and pants pockets. The satisfaction for opening easiness of hips opening part was very low(2.64).

A Light Incident Angle Stimulated Memristor Based on Electrochemical Process on the Surface of Metal Oxide

  • Park, Jin-Ju;Yong, Gi-Jung
    • Proceedings of the Korean Vacuum Society Conference
    • /
    • 2014.02a
    • /
    • pp.174-174
    • /
    • 2014
  • Memristor devices are one of the most promising candidate approaches to next-generation memory technologies. Memristive switching phenomena usually rely on repeated electrical resistive switching between non-volatile resistance states in an active material under the application of an electrical stimulus, such as a voltage or current. Recent reports have explored the use of variety of external operating parameters, such as the modulation of an applied magnetic field, temperature, or illumination conditions to activate changes in the memristive switching behaviors. Among these possible choices of signal controlling factors of memristor, photon is particularly attractive because photonic signals are not only easier to reach directly over long distances than electrical signal, but they also efficiently manage the interactions between logic devices without any signal interference. Furthermore, due to the inherent wave characteristics of photons, the facile manipulation of the light ray enables incident light angle controlled memristive switching. So that, in the tautological sense, device orienting position with regard to a photon source determines the occurrence of memristive switching as well. To demonstrate this position controlled memory device functionality, we have fabricated a metal-semiconductor-metal memristive switching nanodevice using ZnO nanorods. Superhydrophobicity employed in this memristor gives rise to illumination direction selectivity as an extra controlling parameter which is important feature in emerging. When light irradiates from a point source in water to the surface treated device, refraction of light ray takes place at the water/air interface because of the optical density differences in two media (water/air). When incident light travels through a higher refractive index medium (water; n=1.33) to lower one (air; n=1), a total reflection occurs for incidence angles over the critical value. Thus, when we watch the submerged NW arrays at the view angles over the critical angle, a mirror-like surface is observed due to the presence of air pocket layer. From this processes, the reversible switching characteristics were verified by modulating the light incident angle between the resistor and memristor.

  • PDF

Dynamic Wave Pressure Study on a Recurved Offshore Structure (곡면 해양구조물에 작용하는 동파력 고찰)

  • Jo, Cheol-Hui
    • Journal of Ocean Engineering and Technology
    • /
    • v.9 no.2
    • /
    • pp.149-155
    • /
    • 1995
  • This study is to investigate the dynamic pressure caused by breaking waves on a recurved offshore structure. A physical modelling was performed in a two-dimensional wave flume. The measuments from the physical modelling were compared with several known equations. The shock and secondary pressures were found to be dependent on water depth, breaking wave height and the size of the air pocket. The maximum pressure was recorded near the still water level and the secondary pressures near the recurved the recurved structure were found to be less than those experienced in a vertical offshore structure.

  • PDF

Development of FEA Custom Application System for Thermal Stress Evaluation of Skirt Type Joint Pressure Vessel (압력용기 Skirt부의 열응력 평가를 위한 유한요소해석 전문가시스템 개발)

  • Ye, Gyoo-Hyeon;Park, Dong-Sung;Choi, Kyeong-Ho
    • Journal of the Korean Society of Manufacturing Process Engineers
    • /
    • v.2 no.1
    • /
    • pp.51-56
    • /
    • 2003
  • A custom application system, which was based on the finite element analysis, for stress on the head-skirt junction of a hot pressure vessel was developed. This is useful computer-based analysis system which designed to provide an analysis technique and knowledge conveniently available to other people. It was found the evaluation of thermal stress of several typed skirt joint of a pressure vessel could be performed early using this system.

  • PDF

Intralobar Pulmonary Sequestration: A Case Report (Intralobar Pulmonary Sequestration: 수술 1예 보고)

  • 양기민;안긍환;김용일
    • Journal of Chest Surgery
    • /
    • v.4 no.1
    • /
    • pp.55-58
    • /
    • 1971
  • Intralobar pulmonary sequestration is rare congenital lung disease, in which systemic artery supplies a congenitally cystic portion of the lung. Patient was 19 years old male whose complaints were fever, chest pain and sputum. Chest film showed a round homogenous density and air-fluid level at the left lower lung field and on bronchogram, contrast materials did not enter the abscess pocket. By operation multiple lung abscess pockets at the lower lobe were noted. An aberrant artery, measuring 0.4cm. in diameter and 2 cm. in length, arised from the aorta just above the diaphragm and entered the pusterior basal segment of left lower lobe. After division of the artery, left lower lobectomy was done ana postoperative hospital course was uneventful. Pathologic findings were multiple lung cysts which were not connected to the left lower lobe bronchi and an aberrant artery which showed elastic lamillation and mild sclerotic change.

  • PDF

An Study on the Non-Exposure Waterproofing Method Laminated Twist Glass Fiber Mesh on Self Adhesion Butyl Rubber Sheet (자착식 부틸고무시트에 다발형 유리섬유직포를 적층한 비노출방수공법에 관한 연구)

  • Bang, Myung-Jin;Park, Jin-Sang;Kang, Hyo-Jin;Oh, Sang-Keun
    • Proceedings of the Korean Institute of Building Construction Conference
    • /
    • 2007.04a
    • /
    • pp.133-136
    • /
    • 2007
  • It has been applied the self adhesion waterproofing sheet which is developed from exist asphalt waterproofing sheet by heat and torch in domestic construction field. However, the problem of waterproofing have constantly happened due to air pocket condition and defect of joint part in waterproofing construction. Therefore, in this study, we would like to analyze the field application as testing in side of materials and construction method of self adhesion butyl rubber sheet and study of the materials performance.

  • PDF

Design and evaluations of Tonpilz Transducers with self noise suppressing structures (저소음 Tonpilz 트랜스듀서의 설계방안 연구)

  • 임종인
    • Proceedings of the Acoustical Society of Korea Conference
    • /
    • 1996.06a
    • /
    • pp.1-3
    • /
    • 1996
  • 수중 트랜스듀서는 진동하는 물체위에 설치되어 다양한 외부 소음원이 유입되는 환경에 노출되어 있다. 외부 소음원으로는 선체 진동. 프로펠러 소음, 그리고 유동 유기 소음들을 들 수 있고, 트랜스듀서의 실제 작동시 이들의 레벨이 상당히 높아서 센서의 정확한 작동에 장애가 되고 있다. 본 논문에서는 외부 소음원에 무관한 고 정밀, 저 소음 특성을 지닌 음향센서를 개발하기 위하여 유한요소법 (FEN)을 사용하여 소음 전달 특성을 분석하고, air pocket과 음향 감쇠층의 다양한 조합으로 이루어진 구조를 개선한 음향센서의 설계 및 내소음성 평가를 하였다. 또한 사용한 음향 감쇠층의 최적 물성을 제시하고자 한다. 그 결과 센서 측면 하단부에 소음원이 위치할 경우 가장 큰 잡음 신호로 작용하며, 구조를 변경한 결과 기존 음향센서에 비해 55% 이상 내 소음성을 증진 시켰다. 그리고 음향 감쇠층의 최적 음향 임피던슨는 1 Mrayl 이하 혹은 4mrayl 이상으로 분석되었다.

  • PDF

Characteristics of sloshing load and flow inside a tank with cylinder structures (실린더 구조물을 설치한 탱크 내부의 슬로싱 하중과 유동 특성)

  • Ki Jong Kim;Hyun-Duk Seo;Daegyoum Kim
    • Journal of the Korean Society of Visualization
    • /
    • v.21 no.1
    • /
    • pp.31-39
    • /
    • 2023
  • Sloshing of the fluid having a free surface produces an impact force on a tank wall subjected to external excitation. This paper investigates the effect of cylindrical structures in a rectangular sloshing tank under translational harmonic excitations. By varying the number of installed cylinders in the tank, the characteristics of the free-surface deformation is experimentally observed, and the peak pressure on the tank wall is extracted by threshold values. To predict the peak pressure, the numerical simulation is also conducted using smoothed particle hydrodynamics (SPH), and the peak values are compared with the experimental results. Furthermore, pressure and velocity fields in the tank and free-surface shape are analyzed at the moment of impact.