• 제목/요약/키워드: X-ray methods

검색결과 2,175건 처리시간 0.027초

Investigating X-ray cavities and the environmental effects

  • Shin, Jaejin;Woo, Jong-Hak;Mulchaey, John S.
    • 천문학회보
    • /
    • 제41권1호
    • /
    • pp.34.2-34.2
    • /
    • 2016
  • X-ray cavities are typically detected as surface brightness depression in X-ray diffuse emission from hot gas in high resolution X-ray images (i.e., Chandra and XMM-Newton). Showing the coincidence of location with radio jets, X-ray cavities imply that the radio jets interact with interstellar/intergalactic medium. It is important to understand them since they can be a clue of understanding AGN feedback to their host galaxies. To understand the physics of the AGN feedback, X-ray cavity has been actively studied while there are only a few statistical studies on X-ray cavity based on small or incomplete samples. Hence, a systematic study with a large sample is needed. With the condition of sufficient X-ray photons to detect surface brightness depression, we constructed a large sample of 133 galaxy clusters, galaxy groups, and individual galaxies to investigate X-ray cavities. We detected 201 cavities from 94 objects using two detection methods (i.e., beta-modeling and unsharp masking method), and confirmed the cavity size-distance relation over a large dynamical range. The size-distance relation does not vary for different environments (i.e., galaxy cluster, groups, and individual galaxies), suggesting that there is little environmental effect on the formation of X-ray cavity.

  • PDF

3차원 X-ray 영상 기법을 이용한 전자부품 검사 기술 연구 (Study for Inspection Method of Electronic Components Using 3-D X-ray Imaging Technology)

  • 심혁훈;박기남;김종형;박희재
    • 한국공작기계학회논문집
    • /
    • 제16권5호
    • /
    • pp.157-161
    • /
    • 2007
  • There are technological changes to reduce the size and weight of electronic components and to accommodate multi-functions in them. To meet this trend, more complicated technological processes are required. To maintain the processes, more accurate inspection systems are also necessary. Therefore, new inspection methods are needed, which is differ from conventional inspection methods such as electrical test methods ICT(In-Circuit Test), FCT(Function Test) and visual test using optical equipments. One of the possible approaches is non-destructive test using X-ray. In this paper, an inspection method using X-ray is developed and applied to inspection of soldering state and internal defects of electronic components.

이동용 치과 X선 발생장치의 누설 및 산란 선량에 관한 연구 (Leakage and scattered radiation from hand-held dental x-ray unit)

  • 김은경
    • Imaging Science in Dentistry
    • /
    • 제37권2호
    • /
    • pp.65-68
    • /
    • 2007
  • Purpose: To compare the leakage and scattered radiation from hand-held dental X-ray unit with radiation from fixed dental X-ray unit. Materials and Methods: For evaluation we used one hand-held dental X-ray unit and Oramatic 558 (Trophy Radiologie, France), a fixed dental X-ray unit. Doses were measured with Unfors Multi-O-Meter 512L at the right and left hand levels of X-ray tube head part for the scattered and leakage radiation when human skull DXTTR III was exposed to both dental X-ray units. And for the leakage radiation only, doses were measured at the immediately right, left, superior and posterior side of the tube head part when air was exposed. Exposure parameters of handheld dental X-ray unit were 70 kVp, 3 mA, 0.1 second, and of fixed X-ray unit 70 kVp, 8 mA, 0.45 second. Results: The mean dose at the hand level when human skull DXTTR III was exposed with portable X-ray unit $6.39{\mu}Gy$, and the mean dose with fixed X-ray unit $3.03{\mu}Gy$ (p<0.001). The mean dose at the immediate side of the tube head part when air was exposed with portable X-ray unit was $2.97{\mu}Gy$ and with fixed X-ray unit the mean dose was $0.68{\mu}Gy$ (p<0.01). Conclusions: The leakage and scattered radiation from hand-held dental radiography was greater than from fixed dental radiography.

  • PDF

Comparative Studies on Cotton Seed Germinability with Tetrazolium Viability Test and X-ray Contrast Methods

  • Na, Young-Wang;Shim, Sang-In;Chung, Jung-Sung;Rho, Il-Rae;Kim, Seok-Hyeon
    • 한국작물학회지
    • /
    • 제59권2호
    • /
    • pp.188-193
    • /
    • 2014
  • Seed viability testing provides valuable information for assessing seed lot germinability. However, most testing methods require destruction of seed prior to test. Because the dissected seeds for viability test cannot be used further evaluation, the nondestructively X-ray photography technique that can be applied for the evaluation of seed quality has been developed. In order to know the validity and accuracy of X-ray photography technique in seed evaluation test that conducted to remove the abnormal seed from a seed lot, we have compared the results from tetrazolium viability test, germination test and X-ray contrast method in cotton. Metallic salts treatment increased the efficiency of X-ray photographic method by enhancing the penetration of X-ray in abnormal or damaged seeds rather than normal seeds that have strong and well-organized tissues in seed. Cotton seeds presoaked for 16 hr in distilled water followed by soaking into metallic salt solution (5% NaI in water) for 60 min were easily classified seeds into dead seed and viable seed based on the radiography images obtained by X-ray radiation. We concluded that soft X-ray photography was reliable to find out the various defective characters due to heat and mechanical damage of seeds.

마이크로 포커스 X-ray CT를 이용한 콘크리트 손상균열의 정량적 평가 (Quantitative Evaluation of Concrete Damage by X-ray CT Methods)

  • 정자혜
    • 지질공학
    • /
    • 제28권3호
    • /
    • pp.455-463
    • /
    • 2018
  • 본 연구에서는 치핑작업중에 콘크리트에 발생할 수 있는 손상균열을 정량분석하기 위해 X-ray CT 이미지를 이용하는 방법을 제안하고자 한다. 이를 위해 치핑작업을 수행한 후, 균열이 발생한 콘크리트 블록을 코어링하여 직경 50 mm, 길이 100 mm의 시편을 준비하였다. 그 후 마이크로 포커스 X-ray CT 촬영을 하여 얻은 이미지를 3D 이미지로 재구성(reconstruction)하였다. 이렇게 얻어진 3D CT 이미지에 3DMA (3 Dimensional Medial axis Analysis)법을 적용하여, 손상 평가 파라메타로 시편의 위치에 따라 균열의 성질을 평가하여 손상을 분석하였다. 분석결과 치핑에 의한 손상은 치핑 표면으로부터 3 cm 깊이까지 발생한 것으로 나타났다. 또한 CT이미지 공간분석법에서 사용되는 여러 파라메타 중 공극률 지표(Porosity index), Burn number 그리고 Medial axis 의 파라메타를 이용해 치핑표면 근처의 손상 분석이 가능하다는 것이 확인되었다. 이 방법은 내부구조에 변화가 발생한 암석을 대상으로 한 연구에서도 비파괴 상태로 내부의 균열 평가, 가시화에 적용가능하다.

수완부골의 X-ray 영상 및 종골의 초음파 영상에서 측정한 골연령을 통한 소아성장에 관한 임상연구 (A Clinical Study on Growth and Development of Children Based on Their Bone Age Measured by Hand's X-ray Image and Calcaneus's Ultrasonic Image)

  • 윤혜진;서정민;강미선;백정한
    • 대한한방소아과학회지
    • /
    • 제22권2호
    • /
    • pp.155-170
    • /
    • 2008
  • Objectives : The purpose of this study was to have better data and to make efficient clinical reviews about children's growth based on two methods; X-ray of hand, and ultrasound of calcaneus. Methods : The study was composed of 100 patients(50 of boys and 50 of girls) who visited in department of pediatrics, O O university oriental hospital considering growth and their development. Bone age was measured by the TW3 method's RUS score in simple X-ray image of hand and bone density through ultrasonic image of calcaneus. To predict children's estimated height, their parent's height, bone age, and present height's percentile was measured. Results and Conclusions : 1. The bone age results from X-ray image of hand and ultrasonic image of calcaneus were correlated. Younger children have older bone age from hand's X-ray than the one from calcaneus's ultrasound. Older children have older bone age from calcaneus's ultrasound than one from hand's X-ray. 2. Predicted adult height by bone age(BH) of hand's X-ray and BH of calcaneus's ultrasound were correlated, but predicted adult height by inheritance(IH) was not correlated with others. 3. Bone age and predicted adult height were correlated with age, height, weight, BMI, and especially with age and height. 4. Measuring bone age by X-ray image of hand and ultrasonic image of calcaneus was simple and effective way of estimating children's growth and development.

  • PDF

단순 방사선 영상 검사를 통한 추나의학적 진단 방법 - 척추.골반변위 명명체계를 중심으로 - (Diagnostic X-ray from the Perspective of Chuna Manual Medicine, Based on the Listing System of Spinal and Pelvic Subluxation)

  • 이진현;김창곤;조동찬;문수정;박태용;고연석;남항우;이정한
    • 척추신경추나의학회지
    • /
    • 제9권1호
    • /
    • pp.1-14
    • /
    • 2014
  • Objective : The purpose of this study is to offer a new approach to diagnostic X-ray in perspective of Chuna manual medicine for clinical application. Methods : Characteristics of each malposition in X-ray were analyzed comprehensively, based on the listing system. By verifying these results, find out the methods of X-ray diagnosis according to the each malposition. Results : 1. Vertebral malposition can be explained by alignment and relative position of vertebral body in the X-ray. To obtain more accurate estimation of subluxation, features of other structures should be considered, such as spinous process, intervertebral foramen and disc space. 2. Pelvic malposition can be determined by relative location of anterior superior iliac spine (ASIS) and posterior superior iliac spine (PSIS) in the X-ray. Also other pelvic parameters should be utilized to make a diagnosis of sacral malposition. Conclusions : Diagnostic X-ray should be applied to many clinicians for reasonable Chuna manual medicine application. And further studies are needed to use the diagnostic X-ray in the perspective of Chuna manual medicine.

  • PDF

앉은 자세 상지 X-ray 검사(Sitting Position Upper Extremity X-ray Examinations)에서 피폭선량 저감화 연구 (A Study on the Gonads Exposure Dose of Upper Extremity Examinations in Sitting Position)

  • 조평곤
    • 대한방사선기술학회지:방사선기술과학
    • /
    • 제34권3호
    • /
    • pp.189-193
    • /
    • 2011
  • 상지 검사(upper extremity X-ray examinations, UEX) 시 환자 위치 잡이로 가장 많이 활용되고 있는 앉은 자세 상지 X-ray 검사(sitting position upper extremity X-ray examinations, SUEX) 시 방사선에 민감한 생식샘과 목적장기 이외 부위에 대한 피폭이 크다고 판단되어 의료기관 별 SUEX 시 납 앞치마(Apron) 착용 유무와 생식샘 및 목적장기 이외 부위에 대한 방사선 피폭과 피폭선량 감소 방안에 대한 연구 결과 거리가 멀어 질수록, 조사야 조절장치를 가능한 목적장기 부위로 제한 조절할수록, 피사체의 두께가 얇을수록 방사선에 의한 피폭은 감소하였고, 생식샘 차폐 유무에 따른 피폭은 생식샘을 차폐했을 때 약 10~50%의 저감화효과를 얻을 수 있었다. 또한 검사 시 apron 착용 유무에 대한 조사에서는 대부분의 경우 apron을 착용하지 않은 것으로 조사되어 시급히 시정되어야 될 것으로 생각된다.

A Copper Shield for the Reduction of X-γ True Coincidence Summing in Gamma-ray Spectrometry

  • Byun, Jong-In
    • Journal of Radiation Protection and Research
    • /
    • 제43권4호
    • /
    • pp.137-142
    • /
    • 2018
  • Background: Gamma-ray detectors having a thin window of a material with low atomic number can increase the true coincidence summing effects for radionuclides emitting X-rays or gamma-rays. This effect can make efficiency calibration or spectrum analysis more complicated. In this study, a Cu shield was tested as an X-ray filter to neglect the true coincidence summing effect by X-rays and gamma-rays in gamma-ray spectrometry, in order to simplify gamma-ray energy spectrum analysis. Materials and Methods: A Cu shield was designed and applied to an n-type high-purity germanium detector having an $X-{\gamma}$ summing effect during efficiency calibration. This was tested using a commercial, certified mixed gamma-ray source. The feasibility of a Cu shield was evaluated by comparing efficiency calibration results with and without the shield. Results and Discussion: In this study, the thickness of a Cu shield needed to avoid true coincidence summing effects due to $X-{\gamma}$ was tested and determined to be 1 mm, considering the detection efficiency desired for higher energy. As a result, the accuracy of the detection efficiency calibration was improved by more than 13% by reducing $X-{\gamma}$ summing. Conclusion: The $X-{\gamma}$ summing effect should be considered, along with ${\gamma}-{\gamma}$ summing, when a detection efficiency calibration is implemented and appropriate shielding material can be useful for simplifying analysis of the gamma-ray energy spectra.

X-선상(線像) 배수혈 진단을 통한 요각통의 침구(鍼灸) 치험 3례(例) (A Case Report of Three Yogaktong(腰脚痛) Patients Treated with Acupuncture and Moxibustion Treatment by Analysing Su-point(背兪穴) compared with X-ray measuring)

  • 홍승원;이용섭
    • Korean Journal of Acupuncture
    • /
    • 제23권2호
    • /
    • pp.79-88
    • /
    • 2006
  • X-선상(線像) 배수혈 진단을 통한 요각통의 침구(鍼灸) 치험 3례(例)로 다음과 같은 지견을 얻었다. 1. 요배통의 치료에 단순 x-ray 영상을 한의학적으로 활용할 수 있다. 2. 단순 x-ray 영상의 척추분절 극돌기의 아탈구(subluxation)는 해당되는 배수혈 및 경락의 병변으로 진단될 수 있다. 3. 아탈구(subluxation)된 극돌기의 배수혈에 해당되는 경락의 합혈과 원혈을 사용할 경우 진단된 배수혈 수준의 척추분절이 교정될 수 있다.

  • PDF