• 한국화재조사학회지
• /
• 제5권1호
• /
• pp.25-28
• /
• 2004

Since the very first use of optical systems in the process industries there has been a tacit assumption that, because they are not electrical, they do not present an ignition risk when used in flammable atmospheres. This paper describes about an optical ignition mechanism from experimental work carnied out by Sira Safety Services Limited(UK) and whether there is sufficient of an ignition risk for precautions to be advisable when optical systems are used in flammable atmospheres.

• 항공우주기술
• /
• 제4권1호
• /
• pp.239-246
• /
• 2005

본 논문에서는 추적레이다의 고출력 전자파에 의한 인체에 대한 영향(HERP)과 추적레이다 자체 장비에 대한 영향 및 동일한 C-Band 주파수 대역 사용으로 발생하는 기상레이다에 대한 전 자파 간섭(EMI) 분석을 실시하여 장비 설치 구역 내 통제가 가능한 인원(Controlled Personnel) 과 통제가 불가능한 인원(Uncontrolled Personnel)에 대한 최소 접근 제한거리를 산출하고 추적레이다 자체 장비에 대한 영향 및 동일한 주파수 대역 사용으로 발생하는 추적레이다와 기상레이다간의 전자파 간섭(EMI)을 해소하기 위한 방안을 제시하였다.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1998년도 하계학술대회 논문집 E
• /
• pp.1749-1751
• /
• 1998

Close to high power radio/radar transmitters there is a possibility that sparks may be occur at discontinuities in metallic structures. If these structures are in an area in which a flammable mixture may be present, there is a possibility that a fire or explosion may be caused by the sparking. A number of assessment procedures for quantification of the hazard have been produced. This paper reviews the bases of the British Standard covering ignition hazards by radio-frequency radiation and presents some ignition test apparatus to access these hazards.

• 한국전자파학회논문지
• /
• 제9권6호
• /
• pp.725-734
• /
• 1998

When the EED is exposed to the high power radiation, it is possible to verify systems survivability through measuring the induced current of EED. The usual method of performing a system level test is to replace the EED's with modified units from which the explosive charge has been removed and replaced with the fiber optic sensor. The thermal transient test was performed to obtain the temperature vs current characteristic curve for optical sensor installed in EED. The currents measured when the system is exposed to a known EME are compared to the proposed specfication about the EED and a decision is made on whether system is safe or not.

• Journal of Radiation Protection and Research
• /
• 제26권3호
• /
• pp.203-206
• /
• 2001

The mathematical processing (unfolding) of pulse height spectra from a scintillation detector helps to calculate the photon fluence rate energy distribution in a measured photon field. The data processing is based on the knowledge of detection system response function and directional dependence respectively. The experimental results of the photon fields measurements in the vicinity of the spent fuel temporary storage and inside the storage hall are presented. The containers Castor 440 are used for temporary storing of the burnt up fuel assemblies in the Czech nuclear power plant Dukovany. A set of periodical measurements was performed in order to get basic information on the time dependence of the photon fields spatial distributions and spectral characteristics in the temporary storage hall and its vicinity. The photon fields were measured by the scintillation system. The obtained photon fields spatial distributions and spectral characteristics present the information on the radiation hazard in the storage.

• Radiation Oncology Journal
• /
• 제35권4호
• /
• pp.359-367
• /
• 2017

Purpose: This study sought to identify potential candidates for adjuvant radiotherapy and patterns of regional failure in patients who underwent curative-intent surgery for gallbladder cancer. Materials and Methods: Records for 70 patients with gallbladder cancer who underwent curative resection at a single institution between 2000 and 2016 were analysed retrospectively. No patients received adjuvant radiotherapy. Initial patterns of failure were evaluated. Regional recurrence was categorized according to the definitions of lymph node stations suggested by the Japanese Society of Hepato-Biliary-Pancreatic Surgery. Results: Median follow-up was 23 months. Locoregional recurrence as any component of first failure occurred in 29 patients (41.4%), with isolated locoregional recurrence in 13 (18.6%). Regional recurrence occurred in 23 patients, and 77 regional recurrences were identified. Commonly involved regional stations were #13, #12a2, #12p2, #12b2, #16a2, #16b1, #9, and #8. Independent prognostic factors for locoregional recurrence were ${\geq}pT2$ disease (hazard ratio [HR], 5.510; 95% confidence interval [CI], 1.260-24.094; p = 0.023) and R1 resection (HR, 6.981; 95% CI, 2.378-20.491; p < 0.001). Conclusion: Patients with pT2 disease or R1 resection after curative surgery for gallbladder cancer may benefit from adjuvant radiotherapy. Our findings on regional recurrence may help physicians construct a target volume for adjuvant radiotherapy.

• Radiation Oncology Journal
• /
• 제29권1호
• /
• pp.44-52
• /
• 2011

목적: 본 연구는 근치적 절제술 후 병기 3의 비소세포성 폐암에서 방사선 치료의 결과와 이에 영향을 주는 예후 인자를 분석해 보고자 하였다. 대상 및 방법: 2000년부터 2007년까지 88명의 환자가 비소세포성 폐암으로 근치적 절제술 후 병기 3기로 진단받았고, 수술 후 방사선 치료를 시행 받았다 이중 80명의 환자가 병기 3A였으며, 8명의 환자가 병기 3B였다. 83명의 환자는 림프절 병기 N2였으며 이들 중 56명은 단일 부위(single-station)의 종격동 림프절 전이였다. 76명은 2차원, 12명은 3차원 입체조형치료로 수술 후 망사선 치료를 받았다. 총 선량은 30.6에서 63 Gy 였으며 중앙값은 54 Gy였다. 36명의 환자가 항암치료를 시행받았다. 결 과: 생존기간은 26~77개월이었다(중앙값, 54개월). 5년 생존율 및 무병생존율은 각각 45%, 38%였다. 전이된 림프절개수가 생존율에 영향을 미치는 인자로 분석되었다(hazard ratio, 1.037; p=0.040). 5년 국소제어율 및 원격 전이제어율은 각각 88%, 48%였다. 종격동 림프절 부위의 전이가 단일 부위(single-station)인 경우가 무병생존율(p=0.0014)과 원격전이제어율(p=0.0044)을 의미 있게 증가시켰다. 총 51명의 재발이 발생하였으며 국소구역 재발은 10명, 원격전이는 41명이었다. 10명의 국소구역 재발 중에 6명은 방사선 치료 범위 내에서 재발하였다. Radiation Therapy Oncology Group(RTOG) 2도의 방사선 폐렴은 3명의 환자에서 보였으며 증상은 진해성 약제만으로도 조절이 잘 되었다. CTCAE 2도의 방사선 식도염은 11명의 환자에서 관찰되었다. 수술 후 방사선 치료로 인한 3도 이상의 심각한 부작용은 관찰되지 않았다. 결 론: 본 연구에서 국소 진행 비소세포성 폐암에서 근치적 수술 후 방사선 치료는 안전하고 임상적으로 적용 가능한 치료법이며, 국소제어를 증가시킬 수 있는 것으로 분석되었다. 예후인자로는 전이된 림프절 개수와 종격동 림프절 부위가 생존율에 영향을 미치는 것으로 분석되었다. 또한 국소 진행 비소세포성 폐암의 대부분의 재발 형태인 원격 전이를 감소시키기 위한 추가적인 노력이 필요할 것으로 생각된다.

• Radiation Oncology Journal
• /
• 제35권3호
• /
• pp.257-267
• /
• 2017

Purpose: Pulmonary toxicities, including infectious pneumonia (IP) and idiopathic pneumonia syndrome (IPS), are serious side effects of total body irradiation (TBI) used for myeloablative conditioning. This study aimed to evaluate clinical factors associated with IP and IPS following TBI. Materials and Methods: Fifty-eight patients with hematologic malignancies who underwent TBI before allogeneic hematopoietic stem cell transplantation between 2005 and 2014 were reviewed. Most patients (91%) received 12 Gy in 1.5 Gy fractions twice a day. Pulmonary toxicities were diagnosed based on either radiographic evidence or reduced pulmonary function, and were subdivided into IP and IPS based on the presence or absence of concurrent infection. Results: Pulmonary toxicities developed in 36 patients (62%); 16 (28%) had IP and 20 (34%) had IPS. IP was significantly associated with increased treatment-related mortality (p = 0.028) and decreased survival (p = 0.039). Multivariate analysis revealed that the risk of developing IPS was significantly higher in patients who received stem cells from a matched unrelated donor than from a matched sibling donor (p = 0.021; hazard ratio [HR] = 12.67; 95% confidence interval [CI], 1.46-110.30). Combining other conditioning agents with cyclophosphamide produced a higher tendency to develop IP (p = 0.064; HR = 6.19; 95% CI, 0.90-42.56). Conclusion: IP and IPS involve different risk factors and distinct pathogeneses that should be considered when planning treatments before and after TBI.

• Radiation Oncology Journal
• /
• 제29권4호
• /
• pp.243-251
• /
• 2011

Purpose: To evaluate the prognostic value of metabolic tumor volume (MTV) and maximum standardized uptake value (SUVmax) on initial positron emission tomography-computed tomography (PET-CT) and investigate the clinical value of SUVmax for early detection of locoregional recurrent disease after postoperative radiotherapy in patients with locally advanced head and neck squamous cell carcinoma (HNSCC). Materials and Methods: A total of 100 patients with locally advanced HNSCC received primary tumor excision and neck dissection followed by adjuvant radiotherapy with or without chemotherapy. The MTV and SUVmax were measured from primary sites and neck nodes. The prognostic value of MTV and SUVmax were assessed using initial staging PET/CT (study A). Follow-up PET/CT scan available after postoperative concurrent chemoradiotherapy or radiotherapy were evaluated for the SUVmax value and correlated with locoregional recurrence (study B). A receiver operating characteristic (ROC) curve analysis was used to define a threshold value of SUVmax with the highest accuracy for recurrent disease assessment. Results: High MTV (>41 mL) is negative prognostic factor for disease free survival (p = 0.041). Postradiation SUVmax was significantly correlated with locoregional recurrence (hazard ratio, 1.812; 95% confidence interval, 1.361 to 2.413; P < 0.001). A cutoff value of 5.38 from follow-up PET/CT was identified as having maximal accuracy for detecting locoregional recurrence by ROC analysis. Conclusion: MTV at staging work-up was significantly associated with disease free survival. The SUVmax value from follow-up PET/CT showed high diagnostic accuracy for the detection of locoregional recurrence in postoperatively irradiated HNSCC.

• Nuclear Engineering and Technology
• /
• 제56권1호
• /
• pp.207-215
• /
• 2024

This study focuses on measuring the levels of naturally occurring radioactivity in the soil of Swabi, Khyber Pakhtunkhwa, Pakistan, as well as the associated health hazard. Thirty (30) soil samples were collected from various locations and analyzed for ²²⁶Ra, ²³²Th, and ⁴⁰K radioactivity levels using a High Purity Germanium detector (HPGe) gamma-ray spectrometer with a photo-peak efficiency of approximately 52.3%. The average values obtained for these radionuclides are 35.6 ± 5.7 Bqkg^-1, 47 ± 12.5 Bqkg^-1, and 877 ± 153 Bqkg^-1, respectively. The level of ²³²Th is slightly higher and ⁴⁰K is 2.2 times higher than the internationally recommended limit of 30 Bqkg^-1 and 400 Bqkg^-1, respectively. Various parameters were calculated based on the results obtained, including Radium Equivalent (Ra_eq), External Hazard (H_ex), Absorbed Dose Rate (D), Annual Gonadal Equivalent Dose (AGDE), Annual Effective Dose Rate, and Excess Lifetime Cancer Risk (ELCR), which are 170.3 ± 24 Bqkg^-1, 0.46 ± 0.06 Bqkg^-1, 81.4 ± 2.04 nGy h^-1, 582 ± 78.08 µSvy^-1, 99.8 ± 13.5 µSv Gy^-1, and 0.349 ± 0.04, respectively. These values are below the limits recommended by the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) in 2002. This study highlights the potential radiation threats associated with natural radioactivity levels in the soil of Swabi and provides valuable information for public health and safety.