• 대한방사선기술학회지:방사선기술과학
• /
• 제44권1호
• /
• pp.39-46
• /
• 2021

This study confirmed the usefulness of the copper filter according to the mode change by comparing and analyzing the energy change according to the application of the copper filter and the change in effective dose and image quality according to the distance to the subject in the DR(Digital Radiography) system. The average energy increased when the copper filter was applied and the reduction rate by 50% of mAs was increased as the thickness of the copper filter increased according to the application of the 10 kVp rule in AEC mode. The effective dose decreased as the thickness increased when the copper filter was applied in AEC(Automatic Exposure Control) mode and manual mode according to the application of the 10 kVp rule, and the decrease rate decreased with increasing 10 kVp increments. As a result of analyzing the dicom images for AEC mode and manual mode with Image J. the PSNR(Peak Signal to Noise Ratio) values were approximate values of less than 30 dB for each mode and for each copper filter thickness. When the copper filter was applied, the average energy increased, so when the 10 kVp rule was applied, the mAs for each mode could be reduced, and the effective dose could also be reduced. However, as the distance and tube voltage increased, the reduction rate of mAs decreased, and the quality of the image was found to decrease when the copper filter was applied, but there was no difference in quality of the image when the copper filter thickness increased.

• Environmental Engineering Research
• /
• 제20권2호
• /
• pp.199-204
• /
• 2015

In this study, a novel phosphorus removal filter made of brass scrubber with higher porosity of over 96% was fabricated and evaluated. The brass scrubber was surface-modified to form copper hydroxide on the surface of the brass, which could be a phosphate removal filter for advanced wastewater treatment because the phosphates could be removed by the ion exchange with hydroxyl ions of copper hydroxide. The evaluation of phosphate removal was performed under the conditions of the batch type in wastewater and continuous type through filters. Filter recycling was also evaluated with retreatment of the surface modification process. The phosphate was rapidly removed within a very shorter contact time by the surface-modified brass scrubber filter, and the phosphate mass of 1.57 mg was removed per gram of the filter. The possibility of this surface-modified brass scrubber filter for phosphorus removal was shown without undesirable sludge production of existing chemical phosphorus removal techniques, and we feel that it would be very meaningful as a new wastewater treatment.

• 대한방사선기술학회지:방사선기술과학
• /
• 제44권6호
• /
• pp.607-613
• /
• 2021

Long-bone examination is mainly used for inspection of the lower extremities. Recently, a long length detector (FXRD-1751S, VIEWORKS, Korea) with three digital detectors attached has been developed. High energy X-rays are used because pelvic areas require high image quality. In this case, X-rays are transmitted a lot in thin areas such as an ankle, and it is not suitable for diagnosing an image. Therefore, this study use copper filters made with 3D printers to increase image quality in the Long-bone inspection. A copper filter was manufactured in consideration of the overall thickness of the lower part. The experiment was conducted in anterior-posterior (AP) and lateral (LAT) positions, depending on the presence or absence of the filter. 5x5 pixels of region of interest (ROI) were selected from the pelvis, knee, and ankle areas. X-rays were irradiated under the conditions of 70 kVp and 40 mAs for AP, 80 kVp, and 63 mAs for lat when without filters, 90 kVp and 80 mAs for AP, 90 kVp and 100 mAs for lat when with filters. signal to noise ratio(SNR) ratio and contrast to noise (CNR) values were measured 1106.38, 14.34 before applying the filter and 1189.32, 70.43 after the filter. For the knee area, 650.44, 97.61 before applying the filter, and 1013.17, 444.24 after applying the filter. For the ankle area, 206.65, 23.68 before applying the filter and 993.50, 136.11 after applying the filter. In the Long-bone examination, SNR and CNR were greatly measured when the filter was applied, confirmed the availability of using the copper additional filter.

• 상하수도학회지
• /
• 제33권2호
• /
• pp.131-140
• /
• 2019

This study used a packed column reactor and a horizontal flow mesh reactor to examine the removal of copper ions from aqueous solutions using pine bark, a natural adsorbent prepared from Korean red pine (Pinus densiflora). Both equilibrium and nonequilibrium adsorption experiments were conducted on copper ion concentrations of 10mg/L, and the removals of copper ions at equilibrium were close to 95%. Adsorption of copper ions could be well described by both the Langmuir and Freundlich adsorption isotherms. The bark was treated with nitric acid to enhance efficiency of copper removal, and sorption capacity was improved by about 48% at equilibrium; mechanisms such as ion exchange and chelation may have been involved in the sorption process. A pseudo second-order kinetic model described the kinetic behavior of the copper ion adsorption onto the bark. Regeneration with nitric acid resulted in extended use of spent bark in the packed column. The horizontal flow mesh reactor allowed approximately 80% removal efficiency, demonstrating its operational flexibility and the potential for its practical use as a bark filter reactor.

• 한국콘텐츠학회논문지
• /
• 제12권8호
• /
• pp.233-239
• /
• 2012

본 연구는 본원에서 사용 중인 DR 장비에 내장되어 있는 구리필터를 이용하여 골반전후방향 촬영 시 영상의 화질을 저하시키지 않으면서 환자의 피폭선량을 줄이고자 실시하였다. 동일 조사선량으로 none filter, 0.1mmCu, 0.2mmCu, 0.3mmCu로 변화시켜 선량을 측정하고 PCXMC 프로그램으로 장기선량을 산출하였다. 결과는 고환과 방광에서 높은 선량이 검출 되었으며 필터 두께가 증가할수록 선량이 감소하였고 감소폭은 0.1mmCu 일 때 가장 크게 나타났다. 또한 촬영된 영상을 3명의 영상의학과 전문의에게 의뢰하여 평가해 본 결과 0.1mmCu를 사용한 영상이 none filter시와 가장 동일한 진단적 가치가 있는 영상으로 평가 되었고 이때 골반부 입사표면선량은 0.895mGy로 none filter 대비 47%의 선량을 줄일 수 있었다. 따라서 골반전후방향 촬영 시 0.1mmCu를 사용하여 촬영하면 환자의 피폭선량을 효과적으로 감소시킬 수 있을 것이다.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2006년도 하계학술대회 논문집 Vol.7
• /
• pp.396-397
• /
• 2006

The novel urine-activated microbatteries have been successfully demonstrated. In this microbattery, a magnesium (Mg) layer and copper chloride (CuCl) in the filter paper are used as the anode and the cathode, respectively. A stack consisting of a Mg layer, CuCl-doped filter paper and a copper (Cu) layer sandwiched between two plastic layers is hot-pressed into the microbatteries at $100^{\circ}C$. The microbatteries can be activated by adding a droplet of human urine. The experimental results show that the microbattery can deliver a maximum voltage of 1.4 V and maximum power of 1.96 mW for the $1\;k{\Omega}$ load resistor.

• 대한방사선기술학회지:방사선기술과학
• /
• 제7권1호
• /
• pp.23-33
• /
• 1984

In the present study, we determined reduction value of radiation on chest film by film method and made a reduction curves. The reduction radio in exposure to radiation was induced by comparative investigation of characteristic curves and reduction one. Basing on these result, we could reduce a radiation dose on body surface in 50% at the time of chest radiography, if 17.8mm aluminium or 0.87mm copper filter were used in addition to conventional filter at 140KV tube voltage. The present study further revealed that the additional use of the aluminium or copper filter at the time of high voltage radiography in chest facilitates to identify an image of some pathologic focus overlapping wist clavicle and ribs.

• 한국지반환경공학회 논문집
• /
• 제3권1호
• /
• pp.27-36
• /
• 2002

본 연구는 동제련슬래그를 지반개량재로써 활용하기 위하여 배수에 대한 적용가능성을 평가한 것이다. 모래말뚝의 모래 대체재로써의 동제련슬래그 활용방안을 검토하였고, 동제련슬래그의 재료특성, 동제련슬래그말뚝이 설치된 복합지반에서의 압밀배수 특성, 배수 필터재로써의 특성 등을 파악하였다. 연구결과, 동제련슬래그는 일반적으로 쓰여지는 모래와 유사한 연직배수효과를 나타내었으므로, 모래말뚝의 모래 대체재로써의 적용은 충분히 가능할 것으로 판단된다. 더욱, 분사현상에 대한 안정성 및 입자 유실에 대한 내적안정성을 검토한 결과, 일반적인 사질토에 비해 한계동수경사가 크게 나타나고, 내적안정성이 우수하게 평가되었다. 따라서 동제련슬래그는 지반조건에 따라 배수 필터기능을 충분히 발휘할 수 있으며, 내적으로도 안정된 배수 필터재로써 사용이 가능한 것으로 판단된다.

• 한국산업정보학회논문지
• /
• 제29권1호
• /
• pp.107-116
• /
• 2024

Copper Filter Dryer(CFD)는 냉동 및 냉방 시스템에서 냉매의 순환 시 불순물을 제거하여 깨끗한 냉매를 유지하는 역할을 하며, CFD의 결함은 냉동 및 냉방 시스템의 누수, 수명 저하 등 제품의 결함으로 이어질 수 있어 품질보증이 필수적이다. 기존에는 품질 검사 단계에서 작업자가 검사하고 결함을 판단하는 방법이 주로 사용되었으나, 이러한 방법은 주관적으로 판단하기 때문에 정확하지 못하다. 본 논문에서는 CFD 축관 및 용접 공정 과정에서 발생하는 결함을 검출하고 기존의 품질 검사를 대체하기 위해 YOLOv7 객체 감지 알고리즘을 사용하여 결함을 검출했고, F1-Score 0.954, 0.895의 검출 성능을 확인하였다. 또한, 결함 이미지의 Timestamp에 해당하는 센서 데이터 분석을 통해 용접 과정 중 발생하는 결함의 원인을 분석하였다. 본 논문은 CFD 공정 중 발생하는 결함을 검출하고 원인을 분석함으로써 제조 품질보증과 개선 방안을 제시한다.

• 한국방사선학회논문지
• /
• 제11권6호
• /
• pp.459-466
• /
• 2017

본 연구는 부가 여과판의 재질로 구리와 니켈을 선정하여 각 물질에 따라 선량과 화질의 차이를 비교 평가하였다. 먼저, 선량에 대한 실험은 흡수선량 측정으로 란도 팬텀을 이용하여 구리 및 니켈의 부가 여과판을 None, 0.1 mm, 0.2 mm, 0.3 mm로 변화시켜 설치하고 120 kVp, 6.3 mAs의 조건으로 조사하였다. 두 번째로, 관전압 변화와 노출지수 변화에 따라 부가 여과판 두께별로 얻은 영상을 Image J 프로그램을 이용하여 SNR과 CNR값을 구하여 영상을 평가 하였다. 흡수선량 측정은 니켈이 구리보다 높게 나왔으며, 두께가 증가할수록 흡수선량은 감소하였다(p<0.05). 관전압이 증가와 노출지수 변화에 대해서도 두 영상에서 유의한 차이를 보이지 않았다(p>0.05). 결론적으로 본 연구는 부가 여과판에서 니켈은 기존의 구리에 비해 피폭선량을 감소하면서도 현재의 영상의 질을 유지할 수 있는 물질임을 알 수 있다.