There are two beamlines (BLs), 4C1 and 4C2, at the Pohang Accelerator Laboratory that are dedicated to small angle X-ray scattering (SAXS). The 4C1 BL was constructed in early 2000 and is open to public users, including both domestic and foreign researchers. In 2003, construction of the second SAXS BL, 4C2, was complete and commissioning and user support were started. The 4C2 BL uses the same bending magnet as its light source as the 4C1 BL. The 4C1 BL uses a synthetic double multilayer monochromator, whereas the 4C2 BL uses a Si(111) double crystal monochromator for both small angle and wide angle X-ray scattering. In the 4C2 BL, the collimating mirror is positioned behind the monochromator in order to enhance the beam flux and energy resolution. A toroidal focusing mirror is positioned in front of the monochromator to increase the beam flux and eliminate higher harmonics. The 4C2 BL also contains a digital cooled charge coupled detector, which has a wide dynamic range and good sensitivity to weak scattering, thereby making it suitable for a range of SAXS and wide angle X-ray scattering experiments. The general performance of the 4C2 BL was initially tested using standard samples and further confirmed by the experience of users during three years of operation. In addition, several grazing incidence X-ray scattering measurements were carried out at the 4C2 BL.
As semiconductor devices are scaled down for better performance and more functionality, the Cu-based interconnects suffer from the increase of the resistivity of the Cu wires. The resistivity increase, which is attributed to the electron scattering from grain boundaries and interfaces, needs to be addressed in order to further scale down semiconductor devices [1]. The increase in the resistivity of the interconnect can be alleviated by increasing the grain size of electroplating (EP)-Cu or by modifying the Cu surface [1]. Another possible solution is to maximize the portion of the EP-Cu volume in the vias or damascene structures with the conformal diffusion barrier and seed layer by optimizing their deposition processes during Cu interconnect fabrication, which are currently ionized physical vapor deposition (IPVD)-based Ta/TaN bilayer and IPVD-Cu, respectively. The use of in-situ etching, during IPVD of the barrier or the seed layer, has been effective in enlarging the trench volume where the Cu is filled, resulting in improved reliability and performance of the Cu-based interconnect. However, the application of IPVD technology is expected to be limited eventually because of poor sidewall step coverage and the narrow top part of the damascene structures. Recently, Ru has been suggested as a diffusion barrier that is compatible with the direct plating of Cu [2-3]. A single-layer diffusion barrier for the direct plating of Cu is desirable to optimize the resistance of the Cu interconnects because it eliminates the Cu-seed layer. However, previous studies have shown that the Ru by itself is not a suitable diffusion barrier for Cu metallization [4-6]. Thus, the diffusion barrier performance of the Ru film should be improved in order for it to be successfully incorporated as a seed layer/barrier layer for the direct plating of Cu. The improvement of its barrier performance, by modifying the Ru microstructure from columnar to amorphous (by incorporating the N into Ru during PVD), has been previously reported [7]. Another approach for improving the barrier performance of the Ru film is to use Ru as a just seed layer and combine it with superior materials to function as a diffusion barrier against the Cu. A RulTaN bilayer prepared by PVD has recently been suggested as a seed layer/diffusion barrier for Cu. This bilayer was stable between the Cu and Si after annealing at
The increasing functional needs of top-quality printing papers and packaging paperboards, and especially the rapid developments in electronic printing processes and various computer printers during past few years, set new targets and requirements for modern paper quality. Most of these paper grades of today have relatively high filler content, are moderately or heavily calendered , and have many coating layers for the best appearance and performance. In practice, this means that many of the traditional quality assurance methods, mostly designed to measure papers made of pure. native pulp only, can not reliably (or at all) be used to analyze or rank the quality of modern papers. Hence, introduction of new measurement techniques is necessary to assure and further develop the paper quality today and in the future. Paper formation , i.e. small scale (millimeter scale) variation of basis weight, is the most important quality parameter of paper-making due to its influence on practically all the other quality properties of paper. The ideal paper would be completely uniform so that the basis weight of each small point (area) measured would be the same. In practice, of course, this is not possible because there always exists relatively large local variations in paper. However, these small scale basis weight variations are the major reason for many other quality problems, including calender blacking uneven coating result, uneven printing result, etc. The traditionally used visual inspection or optical measurement of the paper does not give us a reliable understanding of the material variations in the paper because in modern paper making process the optical behavior of paper is strongly affected by using e.g. fillers, dye or coating colors. Futhermore, the opacity (optical density) of the paper is changed at different process stages like wet pressing and calendering. The greatest advantage of using beta transmission method to measure paper formation is that it can be very reliably calibrated to measure true basis weight variation of all kinds of paper and board, independently on sample basis weight or paper grade. This gives us the possibility to measure, compare and judge papers made of different raw materials, different color, or even to measure heavily calendered, coated or printed papers. Scientific research of paper physics has shown that the orientation of the top layer (paper surface) fibers of the sheet paly the key role in paper curling and cockling , causing the typical practical problems (paper jam) with modern fax and copy machines, electronic printing , etc. On the other hand, the fiber orientation at the surface and middle layer of the sheet controls the bending stiffness of paperboard . Therefore, a reliable measurement of paper surface fiber orientation gives us a magnificent tool to investigate and predict paper curling and coclking tendency, and provides the necessary information to finetune, the manufacturing process for optimum quality. many papers, especially heavily calendered and coated grades, do resist liquid and gas penetration very much, bing beyond the measurement range of the traditional instruments or resulting invonveniently long measuring time per sample . The increased surface hardness and use of filler minerals and mechanical pulp make a reliable, nonleaking sample contact to the measurement head a challenge of its own. Paper surface coating causes, as expected, a layer which has completely different permeability characteristics compared to the other layer of the sheet. The latest developments in sensor technologies have made it possible to reliably measure gas flow in well controlled conditions, allowing us to investigate the gas penetration of open structures, such as cigarette paper, tissue or sack paper, and in the low permeability range analyze even fully greaseproof papers, silicon papers, heavily coated papers and boards or even detect defects in barrier coatings ! Even nitrogen or helium may be used as the gas, giving us completely new possibilities to rank the products or to find correlation to critical process or converting parameters. All the modern paper machines include many on-line measuring instruments which are used to give the necessary information for automatic process control systems. hence, the reliability of this information obtained from different sensors is vital for good optimizing and process stability. If any of these on-line sensors do not operate perfectly ass planned (having even small measurement error or malfunction ), the process control will set the machine to operate away from the optimum , resulting loss of profit or eventual problems in quality or runnability. To assure optimum operation of the paper machines, a novel quality assurance policy for the on-line measurements has been developed, including control procedures utilizing traceable, accredited standards for the best reliability and performance.
본 연구의 목적은 뇌 자기공명영상에서 확산강조 검사에 대한 SE-EPI 기법과 SSH - TSE 기법에 대한 영상의 질을 알아보고자 한다. MRDWI 검사를 시행한 환자를 무작위로 선정한 PACS 전송 데이터 35명 중 정상 남자 12명, 정상 여자 13명, 뇌경색 10명 중 남자 5 여자 5, 평균나이 68 ± 7.32를 대상으로 데이터를 분석하였다. 사용된 장비는 Ingenia CX 3.0T을 사용하였고 데이터 획득을 위하여 SSH-TSE, SE-EPI 펄스시퀀스와 32 Channel Head Coil를 이용하였다. 영상평가는 paired t-test와 Wilcoxon 검정을 하였으며 p 값이 0.05 이하 일 때 유의성이 있는 것으로 간주하였다. DWI 영상에 대한 SNR대한 정량적 분석 결과 ADC(s/mm2), Diffusion b=0, 1000영상에서 4 부위(WM, GM, BG, Cerebellum)의 평균 및 표준편차 값이 SE-EPI기법(ADC:120.50 ± 40, b=0: 54.50 ± 35.91, b=1000: 91.61 ± 36.63)이 SSH-TSE(ADC:99.69 ± 31.10, b=0: 43.52 ± 25.00 , b=1000: 60.74 ± 24.85) 보다 높게 나타났다(p<0.05). GM-WM, BG-WM 부위에 대한 CNR 값 또한 SE-EPI기법(ADC:116.08 ± 43.30 , b=0: 27.23 ± 09.10 , b=1000: 78.50 ± 16.56)이 SSH-TSE(ADC:101.08 ± 36.81, b=0: 23.96 ± 07.79 , b=1000: 74.30 ± 14.22) 보다 높게 나타났다(p<0.05). 관찰자의 시각적 평가로서 SSH-TSE, SE-TSE에 대한 Ghost 인공물 자화율 인공물, 전반적인 영상의질 모두 SSH-TSE 기법이 높은 결과를 얻었다(ADC:3.6 ± 0.1, 2.8 ± 0.2, b=0: 4.3 ± 0.3, 3.4 ± 0.1 b=1000: 4.3 ± 0.2, 3.5 ± 0.2, p=0.000). 결론적으로, SSH-TSE, SE-EPI를 사용한 SNR, CNR 측정에서 SE-EPI 기법이 우위의 결과를 얻었다. 정성적 분석에서는 펄스시퀀스 특성에 따라 SSH-TSE 펄스시퀀스가 높은 결과를 얻었다.
본 연구의 목적은 다양한 생분해성 멀칭필름을 사용한 콩 재배지에서 작물 생육, 수량, 필름 분해율, 토양 화학성 및 물리성 등을 조사하여 안전하게 사용할 수 있는지를 알아보고자 수행하였다. 2022년과 2023년 콩의 초장, 분지수 및 엽록소 함량은 조사 시기에 상관없이 PE필름과 생분해성 멀칭필름 간에 유의적인 차이가 없었다. 또한 콩 수량구성 요소 및 수량은 시험기간(2022, 2023)에 상관없이 PE필름과 생분해성 멀칭필름 간에 유의적인 차이가 없었다. 생분해성 멀칭필름의 투광율은 콩 이식 후 112일에 6.4~15.8%를 보였고, 2022년보다는 2023년에 높았다. 2022년과 2023년 생분해성 멀칭필름의 붕괴정도는 콩 이식 후 20일부터 시작하였고, 시간이 경과할수록 증가하였다. 또한 콩 수확 후 포장에 잔재한 생분해성 멀칭필름은 수확 후 50일에 대부분 붕괴되었다. 콩 이식 후 112일에 생분해성 멀칭필름의 분해율의 경우 2022년에는 9.8~26.7%를 보였고, 2023년에는 13~36%을 보였다. 토양 pH와 EC는 조사 연도와 조사 시기에 따라 차이를 보였지만, 전반적으로 생분해성 멀칭필름과 PE필름 간에 유의적인 차이가 없었다. 토양 유기물, 질산태질소와 치환성양이온 함량은 생분해 필름 종류에 상관없이 PE필름과 유의적인 차이를 보이지 않았다. 그러나 유효인산 함량은 E, S 및 T 생분해성 멀칭필름이 PE필름에 비해 유의적으로 높았다. 토양 물리성(토성, 용적 밀도, 공극률 등)도 생분해성 멀칭필름과 PE필름 간의 유의적인 차이가 없었다. 2022년과 2023년 토양온도와 수분은 생분해성 멀칭필름과 PE필름 간에 차이가 없으나, 토양 온도는 무멀칭에 비해 2℃ 정도 상승하였고, 토양수분은 5~15% 정도 증가하였다. 생분해성 필름을 사용한 콩 재배지 토양에 후작물 보리 재배 시 생육에는 영향을 미치지 않았다. 따라서 본 연구에 사용된 생분해성 멀칭필름은 콩의 생육, 수량 및 토양환경에 부정적인 영향 없이 안전하게 사용할 수 있을 것으로 판단되었다.
The wall shear stress in the vicinity of end-to end anastomoses under steady flow conditions was measured using a flush-mounted hot-film anemometer(FMHFA) probe. The experimental measurements were in good agreement with numerical results except in flow with low Reynolds numbers. The wall shear stress increased proximal to the anastomosis in flow from the Penrose tubing (simulating an artery) to the PTFE: graft. In flow from the PTFE graft to the Penrose tubing, low wall shear stress was observed distal to the anastomosis. Abnormal distributions of wall shear stress in the vicinity of the anastomosis, resulting from the compliance mismatch between the graft and the host artery, might be an important factor of ANFH formation and the graft failure. The present study suggests a correlation between regions of the low wall shear stress and the development of anastomotic neointimal fibrous hyperplasia(ANPH) in end-to-end anastomoses. 30523 T00401030523 ^x Air pressure decay(APD) rate and ultrafiltration rate(UFR) tests were performed on new and saline rinsed dialyzers as well as those roused in patients several times. C-DAK 4000 (Cordis Dow) and CF IS-11 (Baxter Travenol) reused dialyzers obtained from the dialysis clinic were used in the present study. The new dialyzers exhibited a relatively flat APD, whereas saline rinsed and reused dialyzers showed considerable amount of decay. C-DAH dialyzers had a larger APD(11.70
The wall shear stress in the vicinity of end-to end anastomoses under steady flow conditions was measured using a flush-mounted hot-film anemometer(FMHFA) probe. The experimental measurements were in good agreement with numerical results except in flow with low Reynolds numbers. The wall shear stress increased proximal to the anastomosis in flow from the Penrose tubing (simulating an artery) to the PTFE: graft. In flow from the PTFE graft to the Penrose tubing, low wall shear stress was observed distal to the anastomosis. Abnormal distributions of wall shear stress in the vicinity of the anastomosis, resulting from the compliance mismatch between the graft and the host artery, might be an important factor of ANFH formation and the graft failure. The present study suggests a correlation between regions of the low wall shear stress and the development of anastomotic neointimal fibrous hyperplasia(ANPH) in end-to-end anastomoses. 30523 T00401030523 ^x Air pressure decay(APD) rate and ultrafiltration rate(UFR) tests were performed on new and saline rinsed dialyzers as well as those roused in patients several times. C-DAK 4000 (Cordis Dow) and CF IS-11 (Baxter Travenol) reused dialyzers obtained from the dialysis clinic were used in the present study. The new dialyzers exhibited a relatively flat APD, whereas saline rinsed and reused dialyzers showed considerable amount of decay. C-DAH dialyzers had a larger APD(11.70