Phương pháp phát nhiễu đồng bộ chống thu bức xạ kênh kề phát ra từ màn hình máy tính dựa trên công nghệ FPGA

Tóm tắt— Đã từ lâu, phương pháp phát nhiễu được sử dụng trong việc chống thu bức xạ điện từ trường từ các thiết bị điện tử. Có hai phương pháp chính thường được sử dụng: phát nhiễu dải rộng và phát nhiễu đồng bộ. Phương pháp phát nhiễu đồng bộ có nhiều ưu điểm hơn so với phương pháp phát nhiễu trên dải rộng. Bài báo này trình bày về phương pháp phát nhiễu chống thu bức xạ đồng bộ từ màn hình máy tính. Nội dung tập trung vào đặc điểm bức xạ cơ bản của tín hiệu video trong màn hình máy tính. Từ đó, chứng minh tín hiệu bức xạ có phổ liên quan chặt chẽ với các tín hiệu đồng bộ sử dụng trong màn hình; phân tích đặc điểm của một số loại cổng video thông dụng; thực hiện việc tìm chế độ và tạo các tín hiệu đồng bộ cho các loại màn hình có cổng video VGA trên một kit FPGA.Abstract— Jamming method have long been used in preventing electromagnetic emanation compromising from electronic devices. Existing two jamming methods, boardband jamming and Synchronization jamming. Synchronization jamming has advantages over broadband jamming. In this article, we present a synchronized technique for preventing evasdropping on the radiation of computer monitors. This paper presents the basic radiation characteristics of video signals from the computer monitor. Demonstration of spectrum signals is closely related to the synchronized signals used in the screen. Analyzing the characteristics of some common types video port and performs mode search and synchronization for VGA monitor video on an FPGA platform.

The hidden risk of ionizing radiation in the operating room: A survey among 258 orthopaedic surgeons in Brazil

Background: This study aims to assess orthopedic surgeon knowledge in Brazil about ionizing radiation and its health implications on surgical teams and patients. Methods: A 15-question survey on theoretical and practical concepts of ionizing radiation was administered during the 23rd Brazilian Orthopaedic Trauma Association annual meeting. The survey addressed issues within orthopedic surgery, such as radiation safety concepts, protection, exposure, as well as the participant gender.Participants were either orthopedic surgeons or orthopedic surgery residents working at institutions in Brazil. Results: One thousand surveys weredistributed,and 258 were answered completely (25.8% response rate).Only 5.8% of participants used basic radiation protection equipment (apron, thyroid shield, and radiation protection glasses); 47.3% used a dosimeter; 2.7% reached the annual maximum permissible radiation dose; 10.5% knew the period of increased risk to fetal gestation; 5.8% knew the maximum permissible radiation dose during pregnancy; 58.5% knew that the hands, eyes, and thyroid are the most exposed areas and at greater risk of radiation-related lesions; 25.2% knew the safe distance from a radiation-emitting tube is 3 meters or more; 44.2% knew the safest positioning of the radiation-emitting tube; 25.2% knew that smaller tubes emit greater radiation at the entrance dose to magnify the image; and 55.4% knew that the surgery team receives more scattered radiation in surgical procedures performed on obese patients. Conclusion: This study revealed inadequate theoretical and practical knowledge about radiation exposureamong orthopaedic surgeons in Brazil. Only a minority of orthopaedic surgeons used basic radiation protection equipment (apron, thyroid shield, and radiation protection glasses). No significant differences in knowledge were found when comparing all orthopedic surgery specialties. Our findings indicate an urgent need for education to increase knowledge among orthopaedic surgeons about the hazards of ionizing radiation. Personal protection and implementation of the ALARA (as low as reasonably achievable) protocol in daily practice are important behaviors to prevent the harmful effects of ionizing radiation.

Ionizing radiation: the silent enemy

Background This study aims to assessment the Brazilian orthopedic surgeon’s knowledge about ionizing radiation and its implications over the health of the surgical team and the patients. Methods A Cross-sectional study was performed using a questionnaire of fifteen questions about theoretical and practical concepts regarding ionizing radiation, during the 23 rd Brazilian Orthopaedic Trauma Association Annual meeting. The participant needed to be an orthopedic surgeon or an orthopedic surgery resident in a Brazilian institution, in order to be included in the study. The questionnaire addressed the specialty within orthopedic surgery, issues such as radiation protection use and safety concepts, participants’ children gender and exposition to radiation. Results 258 questionnaires were fully answered. Only 5.8% of the participants use the three basic radiation protection equipment (apron, thyroid shield, and radiation protection glasses); 47.3% use the dosimeter; 2.7% hit the acceptable annual maximum radiation dose; 10.5% knew the gestation period of greater risk to the fetus and 5.8%, the acceptable maximum radiation dose during pregnancy; 58.5% got right that the hands, the eyes and the thyroid are the most exposed and at greater risk of radiation related lesions; 25.2% knew that the distance of 3 meters or more from the radiation-emitting tube is safe; 44.2% knew the safest positioning of the radiation-emitting tube; 25.2% got right that smaller tubes emit greater entrance dose to magnify the image and, therefore, emit more radiation; and 55.4% knew that the surgery team receives more scattered radiation in surgical procedures performed in obese patients. Conclusion It is needed an immediate educational overall plan to orthopedic surgeons and orthopedic surgery residents, so that surgical staff and patients may be less exposed and, therefore, less vulnerable to harmful effects of ionizing radiation.

Use of RESRAD-Onsite 7.2 Code to Assess Environmental Risk around Tudor Shaft Mine Tailing Sites

The RESRAD-onsite 7.2 code has been used to assess the total dose rate in Tudor shaft site contaminated over an area of 10 km2. The risk analysis simulation was span over a period of 1.0E+3 years. The maximum total dose of 1.64 mSv/yr was obtain at t = 8.17 ± 0.02 years. The total peak dose at time t = 0 yr. is 1.63 ± 1.0 mSv/yr for all pathways. This value is 6.53 times higher compare to the basic radiation dose limit of 2.5E-01 mSv/yr. The evaluated excess cancer risk was 3.46E-3 and is 10 times higher compared to the recommended limit of WHO. A cover layer depth of 1.25 m was simulated using the code and a total maximum peak dose for all pathways was 2.52E-01 mSv/yr at t = 5.0E+2 ± 1.0 years.