• Title/Summary/Keyword: Cavity Length

Search Result 459, Processing Time 0.033 seconds

Surgical management of idiopathic bone cavity: case series of consecutive 27 patients

  • You, Myoung-Sang;Kim, Dong-Young;Ahn, Kang-Min
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
    • /
    • v.43 no.2
    • /
    • pp.94-99
    • /
    • 2017
  • Objectives: Idiopathic bone cavity (IBC) is an uncommon intra-osseous cavity of unknown etiology. Clinical features of IBC are not well known and treatment modalities of IBC are controversial. The purpose of this study was to investigate the clinical characteristics of 27 IBC patients who underwent surgical exploration. Materials and Methods: A total of 27 consecutive patients who underwent surgery due to a jaw bone cavity from April 2006 to February 2016 were included in this study. Nine male and 18 female patients were enrolled. Patients were examined retrospectively regarding primary site, history of trauma, graft material, radiographic size of the lesion, presence of interdental scalloping, erosion of the inferior border of the mandible, complications, results of bone graft, and recurrence. Results: Female dominance was found. Maxillary lesion was found in one patient, and bilateral posterior mandibular lesions were found in two patients. The other patients showed a single mandibular lesion. The posterior mandible (24 cases) was the most common site of IBC, followed by the anterior mandible (5 cases). Two patients with anterior mandibular lesion reported history of trauma due to car accident, while the others denied any trauma history. Radiographic cystic cavity length over 30 mm was found in 10 patients. Seven patients showed erosion of the mandibular inferior border. The operations performed were surgical exploration, curettage, and bone or collagen graft. One bilateral IBC patient showed recurrence of the lesion during follow-up. Grafted bone was integrated into the native mandibular bone without infection. One patient reported necrosis of the mandibular incisor pulp after operation. Conclusion: Differential diagnosis of IBC is difficult, and IBC is often confused with periapical cyst. Surgical exploration and bone graft are recommended for treating IBC. Endodontic treatment of involved teeth should be evaluated before operation. Bone graft is recommended to reduce the healing period.

The Susceptibility of Electronic Circuits inside the Cavity by HPEM(High Power Electromagnetics) Environment (금속 함체내부로 입사되는 고출력 전자기 펄스에 대한 전자회로의 민감성 분석)

  • Hwang, Sunl-Mook;Kwon, Hae-Ok;Huh, Chang-Su;Choi, Jin-Soo
    • The Transactions of The Korean Institute of Electrical Engineers
    • /
    • v.61 no.12
    • /
    • pp.1892-1897
    • /
    • 2012
  • Modern electronic circuits are of importance for the function of communication, traffic systems and security systems. An intentional threat to these systems could be of big casualties and economic disasters. This study has examined susceptibility of electronic circuits inside the cavity by HPEM(High Power Electromagnetics). The UWB measurements were done at an anechoic chamber using a RADAN voltage source, which can generate a transient impulse of about 200 kV. The HPEM wave penetrated inside the metal case appeared to the long damped ringwave of pulse length compared with the incident wave. In addition, the resonant frequency generated inside the metal case occurred primarily in the range of 1~3 GHz. The frequency band of 1~3 GHz was influenced on the electronic circuit, which was confirmed by an external antenna and an internal absorber. The electronic circuit was influenced by HPEM infiltrated into the cavity at the 86 kV/m out of the metal cases. Also in case of an absorber the susceptibility of an electronic circuit was smallest among other cases(aperture, antenna). It is considered that absorber has a function absorbing electromagnetic wave infiltrated into the cavity and simultaneously limiting resonance by varying a boundary condition inside the cavity. Based on the results, electronic equipment systems could be applied to protection that has suited system requirements.

Numerical Analysis on the Heat Transfer Characteristics of Benard Flow in a Magnetic Fluids (자성유체의 Benard 유동에서 열전달특성에 관한 수치적 연구)

  • Park, J.W.;;Seo, L.S.;Jun, C.H.;Kim, Y.S.
    • Journal of the Korean Magnetics Society
    • /
    • v.13 no.1
    • /
    • pp.41-46
    • /
    • 2003
  • This study deals with the Benard flow of magnetic fluids in a rectangular cavity. The ratio of height to length of the cavity is 1 : 4 and the bottom of the cavity is assumed to be a heating face while the other sides are to be cooling faces. When magnetic field was equally impressed, considering the internal rotation of the elementary ferromagnetic particle, we found the following result from the numerical analysis of the GSMAC algorithm applied to the equations for the magnetic fluid. Benard flow was controled by the intensity and the direction of magnetic fields, and a critical point was appeared when the magnetic field near H=-7000 was applied.

A Study of the Estimation Method for the Dielectric Properties of Dielectrics in Millimeter Wave Range using Bethe's Small Hole Coupling (Bethe's Small Hole Coupling을 이용한 유전체의 밀리미터파대 유전특성 평가방법에 관한 연구)

  • Lee, Hong-Yeol;Jun, Dong-Suk;Hahn, Jin-Woo;Lee, Sang-Seok
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2002.07b
    • /
    • pp.1136-1139
    • /
    • 2002
  • The circular cavity resonator which can measure the dielectric properties of dielectrics in the Ka-band(26.5GHz~40GHz) frequency range was designed and fabricated. A structure of the resonator is divided into two equal parts of the length and the dielectric plate sample is placed between two halves. Exciting and detecting of the resonator is performed by WR28 rectangular waveguides using Bethe's small hole coupling. The GaAs plate sample, whose permittivity is known to be 13 in millimeter wave range, was used for the verification of the performance of the fabricated circular cavity resonator. In the measurement of GaAs single crystal using that resonator, the resonant frequency of the dominant $TE_{011}$ mode, the permittivity and $Q{\times}f_0$ were measured as 26.69GHz, 12.9 and 124,000GHz, respectively.

  • PDF

Continuous variation characteristics of pulse width in short cavity dye laser (단공진기 색소레이저의 펄스폭 연속가변 특성)

  • 김용평
    • Korean Journal of Optics and Photonics
    • /
    • v.10 no.6
    • /
    • pp.512-517
    • /
    • 1999
  • Quenched dye laser (QDL), which operates with relaxation oscillation mode, is one of the most powerful source for ultra-short pulse light. In this paper, the output characteristics of QDL is theoretically analyzed by a computer simulation. The QDL is assumed that the laser dye is Rhodamine 6G which has the oscillation wavelength of 590 nrn and that the active length is 5 mm and that the pumping source is XeCllaser which has oscillation wavelength of 308 nm. It is revealed ilim the pulse width of short cavity dye laser reduced less than 1/100 than pumping pulse duration and has the linear relationship with spatial width of pumping beam approximately. In addition, it is revealed that the short cavity dye laser is a powerful candidate of pulse width variable light source, which is adjusted by spatial size of pumping beam_ beam_

  • PDF

A Study of the Estimation Method for the Dielectric Properties of Dielectrics in Millimeter Wave Range using Bethe's Small Hole Coupling (Bethe's Small Hole Coupling을 이용한 유전체의 밀리미터파대 유전특성 평가방법에 관한연구)

  • 이홍열;전동석;한진우;이상석
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.15 no.12
    • /
    • pp.1085-1089
    • /
    • 2002
  • The circular cavity resonator which can measure the dielectric properties of dielectrics in the Ka-band(26.5GHz∼400Hz) frequency range was designed and fabricated. A structure of the resonator is divided into two equal parts of the length and the dielectric plate sample is placed between two halves. Exciting and detecting of the resonator is Performed by WR28 rectangular waveguides using Bethe's small hole coupling. The GaAs plate sample, whose performance is known to be 13 in millimeter wave range, was used for the verification of the performance of the fabricated circular cavity resonator In the measurement of GaAs single crystal using that resonator, the resonant frequency of the dominant TE$\sub$011/ mode, the permittivity and Q${\times}$f$\sub$0/ were measured as 26.69GHz, 12.9 and 124,000GHz, respectively.

A Linearly Polarized Long-Cavity Yb:YAG Laser with a Variable-Reflectivity Output Coupler (반사도 가변형 출력경을 갖는 긴 공진기형 선편광 Yb:YAG 레이저의 출력 특성 연구)

  • Kim, Hyun Chul;Lim, Han Bum;Kim, Hyun Su
    • Korean Journal of Optics and Photonics
    • /
    • v.26 no.1
    • /
    • pp.38-43
    • /
    • 2015
  • We propose a linearly polarized long-cavity Yb:YAG laser with a variable-reflectivity output coupler and investigate its output characteristics. The variable output coupler consists of a polarized beam splitter and a quarter-wave plate. The linearly polarized laser has a long cavity length of about 3.7 m. The slope efficiency of the proposed laser is 19%, and the beam quality ($M^2$) is about 1.2.

The Limitation and Applicabilitity of Helmholtz Resonator, Regarding as Equivalent Single-Degree of Vibration System (1자유도 등가 진동계로 이해하는 헬름홀츠 공명기 특성의 한계점과 응용)

  • 하상태;김양한
    • Journal of KSNVE
    • /
    • v.4 no.2
    • /
    • pp.209-219
    • /
    • 1994
  • Classical method calculates the resonance frequency of Helmholtz resonator by postulating that there is a moving mass in neck and a stiffness which expresses the compressibility of cavity. This has been widely accepted as reasonable to determine the resonant frequency, provided that the wave length of interest is longer that any length scale of resonater. Nevertheless, it has been often recognized that this classical method sometimes does not well predict the resonant frequency. This paper decribes the way in which the dynamics of resonator very often does care about the detail geometries of resonator; location of the neck, diameter ratio of the neck to that of cavitty, length of resonator compared with that of neck, etc. This rather unexpected observations have been proved theoretically; 3 dimensional analysis of acoustic wave equation, as well as experimentally by comparing the resonant frequencies, transmission loss, and insertion loss of resonator.

  • PDF

Effects of Wavelength Dependent Birefringence inside a Fiber Cavity on the Fiber Laser Output Characteristics with a Nonlinear Amplifying Loop Mirror

  • Kim, Ho-Young;Kim, Kyong-Hon;Lee, El-Hang
    • Journal of the Optical Society of Korea
    • /
    • v.2 no.2
    • /
    • pp.64-73
    • /
    • 1998
  • We have theoretically analyzed and experimentally observed the effects of wavelength dependent birefringence inside a laser cavity on the output characteristics of fiber lasers with a figure eight geometry. The spectral and polarization characteristics of fiber lasers are found to be very susceptible to the resultant birefringence composed of the intrinsically existing wavelength dependent birefringence and the externally induced birefringences inside the fiber. For the variation of twist-induced birefringence inside the nonlinear amplifying loop mirror, the laser output power and center wave-length of continuous wave lasers change periodically, but the polarization characteristics remains nearly unchanged. The changes of the birefringence inside the linear loop has little effect on the spectral characteristics but changes the polarization properties such as the polarization direction.

High speed machining of cavity pattern in prehardened mold using the small size tool (소경 공구를 이용한 고경도 패턴 금형의 고속 가공)

  • Im, Pyo;Jang, Dong-Kyu;Lee, Hee-Kwan;Yang, Kyun-Eui
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.21 no.1
    • /
    • pp.133-139
    • /
    • 2004
  • High speed machining (HSM) can reduce machining time with the high metal removal rate by high speed spindle and feedrate. This paper supports HSM technology using the small size tool with the optimal tool path generation and modification of tool change. The optimum tool path is generated to reduce cutting length of cavity pattern and change the cutting tool for preventing the tool breakage by wear. The tool path is modified with the experiment data of tool wear and breakage to support tool change on reasonable time. The result can contribute to HSM technology of high hardness materials using the small size end-mill.