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Sample records for dsa method

  1. Set-up for lifetime measurements with the DSA method

    Energy Technology Data Exchange (ETDEWEB)

    Avrigeanu, V.; Bucurescu, D.; Ivascu, M.; Osvath, E.; Popescu, D.; Stog, O.

    1975-01-01

    A set-up for the measurement of short nuclear lifetimes at the IAP U-120 cyclotron, by means of the Doppler shift attenuation method (DSAM) is described. A 100 mm diameter reaction chamber is used, with a transparent window which allows visualization of the beam spot on the target. The electronic block scheme is discussed. As a test measurement for this set-up the determination of the lifetime of the first 2/sup +/ state in /sup 30/Si by means of the /sup 27/Al(..cap alpha..,p..gamma..)/sup 30/Si reaction is presented. 5 figures.

  2. Reproducibility of Middle Cerebral Artery Stenosis Measurements by DSA: Comparison of the NASCET and WASID Methods.

    Directory of Open Access Journals (Sweden)

    Luguang Chen

    Full Text Available To evaluate the intra- and inter-observer variability of the North American Symptomatic Carotid Endarterectomy Trial (NASCET and Warfarin-Aspirin Symptomatic Intracranial Disease (WASID criteria for the evaluation of middle cerebral artery (MCA stenosis using digital subtraction angiography (DSA.DSA images of 114 cases with 131 stenotic MCAs were retrospectively analyzed. Two radiologists and a researcher measured the degree of MCA stenosis independently using both NASCET and WASID methods. To determine intra-observer agreement, all the observers reevaluated the degree of MCA stenosis 4 weeks later. The linear relation and coefficient of variation (CV between the measurements made by the two methods were assessed by correlation coefficient and multi-factor analysis of variance (ANOVA, respectively. Intra- and inter-observer variability of the two methods was evaluated by intraclass correlation coefficient (ICC, Spearman's R value, Pearson correlation coefficient and Bland-Altman plots.Despite the fact that the degree of MCA stenosis measured by NASCET was lower than measured using the WASID method, there was good linear correlation between the measurements made by the two methods (for the mean measurements of the 3 observers, NASCET% = 0.891 × WASID% - 1.89%; ICC, Spearman's R value and Pearson correlation were 0.874, 0.855, and 0.874, respectively. The CVs of both intra- and inter-observer measurements of MCA stenosis using WASID were significantly lower than that using NASCET confirmed by the multi-factor ANOVA results, which showed only the measurement methods of MCA stenosis had significant effects on the CVs both in intra- and inter-observer measurements (both P values < 0.001. Intra-observer measurements showed good or excellent agreement with respect to WASID and NASCET evaluation (ICC, 0.656 to 0.817 and 0.635 to 0.761, respectively. Good agreement for the WASID evaluation (ICC, 0.592 to 0.628 and for the NASCET evaluation (ICC, 0

  3. DSA Image Blood Vessel Skeleton Extraction Based on Anti-concentration Diffusion and Level Set Method

    Science.gov (United States)

    Xu, Jing; Wu, Jian; Feng, Daming; Cui, Zhiming

    Serious types of vascular diseases such as carotid stenosis, aneurysm and vascular malformation may lead to brain stroke, which are the third leading cause of death and the number one cause of disability. In the clinical practice of diagnosis and treatment of cerebral vascular diseases, how to do effective detection and description of the vascular structure of two-dimensional angiography sequence image that is blood vessel skeleton extraction has been a difficult study for a long time. This paper mainly discussed two-dimensional image of blood vessel skeleton extraction based on the level set method, first do the preprocessing to the DSA image, namely uses anti-concentration diffusion model for the effective enhancement and uses improved Otsu local threshold segmentation technology based on regional division for the image binarization, then vascular skeleton extraction based on GMM (Group marching method) with fast sweeping theory was actualized. Experiments show that our approach not only improved the time complexity, but also make a good extraction results.

  4. Digital subtaction angiography (DSA) in renal-related conditions

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    Kim, Dae Ho; Jeong, Seong Wook; Bae, Kwang Soo; Chung, Moo Chan; Kim, Ki Jeong [Soon Chun Hyang University College of Medicine, Asan (Korea, Republic of)

    1986-10-15

    DSA (Digital Subtraction Angiography) is a valuable diagnostic imaging method in many clinical fields, including renal-related conditions. Sixty four renal DSA examination were performed in 59 patients with renal-related diseases from Jan. 1984 to Dec. 1985. Summary of These were as follows: 1. Intraarterial(IA)-DSA is performed in 6 cases, intravenous(IV)-DSA in 58 cases. In 58 Examinations of IV-DSA, diagnostic image quality is obtained in 51 cases (88%). 2. In investigations of a possible renovascular etiology of hypertension, IV-DSA is a simple, safe, sensitive and accurate method. On screening for evaluation of renovascular hypertension, RSP should be replaced with IV-DSA, because IV-DSA is more sensitive and accurate and can detect not only anatomic change of renal artery but also functional hemodynamic change. 3. IV-DSA is valuable in diseases with morphologic changes of vessels. In characterization of a known renal mass, and evaluation of hematuria, suspected aneurysm and renal trauma, IV-DSA is very useful diagnostic imaging modality. 4. In evaluation of potential renal donors, IV-DSA is an accurate and safe method with 82.4% of accuracy. IV-DSA also is useful in follow-up of allograft recipients. 5. In investigation of diabetic nephropathy, glomerulonephritis, pyelonephritis, IV-DSA is little helpful. 6. The advantages of DSA are well known, particularly post-procedure process using computer program is helpful for obtaining information's of hemodynamic change or time-suquence-curve of density etc. More technical improvement with this modality is required for improvement of the image quality and resolution. And more accumulation of clinical experience is required in order to increase the diagnostic accuracy.

  5. Incorporating DSA in multipatterning semiconductor manufacturing technologies

    Science.gov (United States)

    Badr, Yasmine; Torres, J. A.; Ma, Yuansheng; Mitra, Joydeep; Gupta, Puneet

    2015-03-01

    Multi-patterning (MP) is the process of record for many sub-10nm process technologies. The drive to higher densities has required the use of double and triple patterning for several layers; but this increases the cost of the new processes especially for low volume products in which the mask set is a large percentage of the total cost. For that reason there has been a strong incentive to develop technologies like Directed Self Assembly (DSA), EUV or E-beam direct write to reduce the total number of masks needed in a new technology node. Because of the nature of the technology, DSA cylinder graphoepitaxy only allows single-size holes in a single patterning approach. However, by integrating DSA and MP into a hybrid DSA-MP process, it is possible to come up with decomposition approaches that increase the design flexibility, allowing different size holes or bar structures by independently changing the process for every patterning step. A simple approach to integrate multi-patterning with DSA is to perform DSA grouping and MP decomposition in sequence whether it is: grouping-then-decomposition or decomposition-then-grouping; and each of the two sequences has its pros and cons. However, this paper describes why these intuitive approaches do not produce results of acceptable quality from the point of view of design compliance and we highlight the need for custom DSA-aware MP algorithms.

  6. 2D-DSA与R-DSA及3D-DSA在脑动脉瘤诊疗中的应用%Comparision of 2D-DSA,R-DSA,3D-DSA in diagnosis and treatment of intracranial aneurysms

    Institute of Scientific and Technical Information of China (English)

    董富山; 翟水亭; 王子亮; 李天晓

    2008-01-01

    Objective To evaluate the advantages of 3D-DSA as compared to 2D-DSA,R-DSA in detecting the saccular size and neck size of the aneurysm and its relationship with parent vessels. Methods Forty-two patients with cerebral aneurysms underwent 3D-DSA,2D-DSA and R-DSA.After standard 2D-DSA3rotational DSA was performed,then R-DSA images were transined to the 3D-workstation.The volume-rendering images were created from the rotational-DSA data sets by the workstation.All images were assessed for overall image quality,presence of aneurysm,visualization of aneurysmal neck,and relationship to adiacent vessels.Statistical analysis was conducted for 50 aneurysms by endovaseular treatment. Results 1.The presence of aneurysm:Three aneurysms that were not detected at 2D-DSA were classified as uncertain on the basis of rotational-DSA.All aneurysms were classified as definitive presence on the basis of volume-rendering findings.2.Overall image quality of rotational-DSA and 3D-DSA was statistically inferior to that of the standard 2D-DSA for visualization of distal arteries.3.For detection of aneurysmal shape,visualization of aneurysmal neck and its relationship to neighboring arteries,volume-rendering images were significantly suDerior to 2D-DSA and R-DSA.Conclusion 3D-DSA is superior to the standard 2D-DSA and R-DSA in diagnosis of intracranial aneurysm,particularly visualization of aneurysmal neck,and this is very important for endovascular treatment of intracranial anerysm.%目的 通过对比2D-DSA、R-DSA与3D-DSA在显示脑动脉瘤瘤体的大小、瘤颈的宽窄及与毗邻血管的关系,说明3D-DSA优于2D-DSA及R-DSA.方法 42例资料完整的颅内动脉瘤患者均行2D-DSA、R-DSA及3D-DSA检查,常规2D-DSA检查后即行R-DSA检查,把R-DSA图像传送到3D工作站,由3D工作站生成容积再现图像(VR).通过图像在对脑动脉瘤瘤体的大小、形态、瘤颈的宽窄与毗邻血管的关系等方面显示评价分析.对50个行血管内栓塞治疗

  7. Fair Electronic Payment Scheme Based on DSA

    Institute of Scientific and Technical Information of China (English)

    WANG Shao-bin; HONG Fan; ZHU Xian

    2005-01-01

    We present a multi-signature scheme based on DSA and describes a fair electronic payment scheme based on improved DSA signatures. The scheme makes both sides in equal positions during the course of electronic transaction. A Trusted Third Party (TTP) is involved in the scheme to guarantee the fairness of the scheme for both sides. However, only during the course of registration and dispute resolution will TTP be needed. TTP is not needed during the normal payment stage.

  8. Effect of hierarchical deformable motion compensation on image enhancement for DSA acquired via C-ARM

    Science.gov (United States)

    Wei, Liyang; Shen, Dinggang; Kumar, Dinesh; Turlapati, Ram; Suri, Jasjit S.

    2008-02-01

    DSA images suffer from challenges like system X-ray noise and artifacts due to patient movement. In this paper, we present a two-step strategy to improve DSA image quality. First, a hierarchical deformable registration algorithm is used to register the mask frame and the bolus frame before subtraction. Second, the resulted DSA image is further enhanced by background diffusion and nonlinear normalization for better visualization. Two major changes are made in the hierarchical deformable registration algorithm for DSA images: 1) B-Spline is used to represent the deformation field in order to produce the smooth deformation field; 2) two features are defined as the attribute vector for each point in the image, i.e., original image intensity and gradient. Also, for speeding up the 2D image registration, the hierarchical motion compensation algorithm is implemented by a multi-resolution framework. The proposed method has been evaluated on a database of 73 subjects by quantitatively measuring signal-to-noise (SNR) ratio. DSA embedded with proposed strategies demonstrates an improvement of 74.1% over conventional DSA in terms of SNR. Our system runs on Eigen's DSA workstation using C++ in Windows environment.

  9. What promotes derected self assembly (DSA)?

    Science.gov (United States)

    Nakagawa, S. T.

    2016-09-01

    A low-energy electron beam (EB) can create self-interstitial atoms (SIA) in a solid and can cause directed self-assembly (DSA), e.g. {3 1 1}SIA platelets in c-Si. The crystalline structure of this planar defect is known from experiment to be made up of SIAs that form well aligned atomic rows on each (3 1 1) plane. To simulate the experiment we distributed Frenkel pairs (FP) randomly in bulk c-Si. Then making use of a molecular dynamic (MD) simulation, we have reproduced the experimental result, where SIAs are trapped at metastable sites in bulk. With increasing pre-doped FP concentration, the number of SIAs that participate in DSA tends to be increased but soon slightly supressed. On the other hand, when the FP concentration is less than 3%, a cooperative motion of target atoms was characterized from the long-range-order (LRO) parameter. Here we investigated the correlation between DSA and that cooperative motion, by adding a case of intrinsic c-Si. We confirmed that the cooperative motion slightly promote DSA by assisting migration of SIAs toward metastable sites as long as the FP concentration is less than 3%, however, it is essentially independent of DSA.

  10. DSA Image Fusion Based on Dynamic Fuzzy Logic and Curvelet Entropy

    Directory of Open Access Journals (Sweden)

    Guangming Zhang

    2009-06-01

    Full Text Available The curvelet transform as a multiscale transform has directional parameters occurs at all scales, locations, and orientations. It is superior to wavelet transform in image processing domain. This paper analyzes the characters of DSA medical image, and proposes a novel approach for DSA medical image fusion, which is using curvelet information entropy and dynamic fuzzy logic. Firstly, the image was decomposed by curvelet transform to obtain the different level information. Then the entropy from different level of DSA medical image was calculated, and a membership function based on dynamic fuzzy logic was constructed to adjust the weight for image subbands coefficients via entropy. At last an inverse curvelet transform was applied to reconstruct the image to synthesize one DSA medical image which could contain more integrated accurate detail information of blood vessels than any one of the individual source images. By compare, the efficiency of our method is better than weighted average, laplacian pyramid and traditional wavelet transform method.

  11. Application of image fusion techniques in DSA

    Science.gov (United States)

    Ye, Feng; Wu, Jian; Cui, Zhiming; Xu, Jing

    2007-12-01

    Digital subtraction angiography (DSA) is an important technology in both medical diagnoses and interposal therapy, which can eliminate the interferential background and give prominence to blood vessels by computer processing. After contrast material is injected into an artery or vein, a physician produces fluoroscopic images. Using these digitized images, a computer subtracts the image made with contrast material from a series of post injection images made without background information. By analyzing the characteristics of DSA medical images, this paper provides a solution of image fusion which is in allusion to the application of DSA subtraction. We fuse the images of angiogram and subtraction, in order to obtain the new image which has more data information. The image that fused by wavelet transform can display the blood vessels and background information clearly, and medical experts gave high score on the effect of it.

  12. ELECTROCHEMICAL OXIDATION OF THE HERBICIDE TEBUTHIURON USING DSA (R)-TYPE ELECTRODE

    OpenAIRE

    Alves, Suellen A.; Ferreira,Tanare C. R.; Lanza, Marcos Roberto Vasconcelos

    2013-01-01

    ELECTROCHEMICAL OXIDATION OF THE HERBICIDE TEBUTHIURON USING DSA (R)-TYPE ELECTRODE. Tebuthiuron (TBH) is a herbicide widely used in different cultures and known for its toxic effects. Electrochemical methods are promising for removing pollutants such as pesticides. This study showed the degradation of TBH using a DSA (R) anode operated at current densities of 50 to 200 mA cm(-2). Removal presented pseudo-first order kinetics while high-pressure liquid chromatography (UV detection) showed two...

  13. Influence of template fill in graphoepitaxy DSA

    Science.gov (United States)

    Doise, Jan; Bekaert, Joost; Chan, Boon Teik; Hong, SungEun; Lin, Guanyang; Gronheid, Roel

    2016-03-01

    Directed self-assembly (DSA) of block copolymers (BCP) is considered a promising patterning approach for the 7 nm node and beyond. Specifically, a grapho-epitaxy process using a cylindrical phase BCP may offer an efficient solution for patterning randomly distributed contact holes with sub-resolution pitches, such as found in via and cut mask levels. In any grapho-epitaxy process, the pattern density impacts the template fill (local BCP thickness inside the template) and may cause defects due to respectively over- or underfilling of the template. In order to tackle this issue thoroughly, the parameters that determine template fill and the influence of template fill on the resulting pattern should be investigated. In this work, using three process flow variations (with different template surface energy), template fill is experimentally characterized as a function of pattern density and film thickness. The impact of these parameters on template fill is highly dependent on the process flow, and thus pre-pattern surface energy. Template fill has a considerable effect on the pattern transfer of the DSA contact holes into the underlying layer. Higher fill levels give rise to smaller contact holes and worse critical dimension uniformity. These results are important towards DSA-aware design and show that fill is a crucial parameter in grapho-epitaxy DSA.

  14. Comparison between sol-gel derived and classic methods for the elaboration process of DSA Ta/IrO{sub 2} electrodes

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    Massot, L.; Palau, P.; Savall, A.; Taxil, P. [Paul-Sabatier Univ., Toulouse (France). Chemical Engineering Lab.

    2006-07-01

    This paper investigated the oxygen evolution of inert anodes in acidic media. The electrodes were composed of a tantalum (Ta) substrate with a catalyst coating of iridium oxide (IrO{sub 2}). Two methods were used to obtain the catalyst coating: (1) a Sol-Gel derived method using iridium acetylacetonate ([CH{sub 3}COCH=COCH{sub 3}]{sub 3}Ir) dissolved in an isopropanol-acetic acid mixture, and (2) iridium chloride (IrCl{sub 4}) dissolved in an ethanol-isopropanol mixture as an iridium oxide precursor. The electrodes were then characterized and compared using thermogravimetric measurements of the precursors. Results of the study showed that the new precursor derived from the Sol-Gel method was more reactive as the IrO{sub 2}3 formation temperature was lower. A higher amount of heat generated by cracking and combustion of the organic compounds was released during the decomposition of the Sol-Gel precursor salts. The enthalpy of conversion into the oxide measured by differential sweeping calorimetry was -15580 J/g in the case of the Sol-Gel derived method and -74.7 J/g in the case of the traditional method. However, the electrodes prepared by the Sol-Gel method were not stable, and the service lives of the electrodes were 4 times less significant than those of the electrodes prepared using the other method due to the low stability of metal iridium under polarization. It was also noted that the fine catalyst particles were less stable during a gaseous evolution. Results indicated that a rise in the thermal processing temperatures may facilitate the formation of iridium oxide, but would involve a more significant oxidation of the substrate. It was concluded that the Sol-Gel method is not suitable for the preparation of Ta/IrO{sub 2} electrodes when the oxidation number of the iridium oxide precursor is 3. 3 refs., 1 tab., 1 fig.

  15. An implementation of differential search algorithm (DSA) for inversion of surface wave data

    Science.gov (United States)

    Song, Xianhai; Li, Lei; Zhang, Xueqiang; Shi, Xinchun; Huang, Jianquan; Cai, Jianchao; Jin, Si; Ding, Jianping

    2014-12-01

    Surface wave dispersion analysis is widely used in geophysics to infer near-surface shear (S)-wave velocity profiles for a wide variety of applications. However, inversion of surface wave data is challenging for most local-search methods due to its high nonlinearity and to its multimodality. In this work, we proposed and implemented a new Rayleigh wave dispersion curve inversion scheme based on differential search algorithm (DSA), one of recently developed swarm intelligence-based algorithms. DSA is inspired from seasonal migration behavior of species of the living beings throughout the year for solving highly nonlinear, multivariable, and multimodal optimization problems. The proposed inverse procedure is applied to nonlinear inversion of fundamental-mode Rayleigh wave dispersion curves for near-surface S-wave velocity profiles. To evaluate calculation efficiency and stability of DSA, four noise-free and four noisy synthetic data sets are firstly inverted. Then, the performance of DSA is compared with that of genetic algorithms (GA) by two noise-free synthetic data sets. Finally, a real-world example from a waste disposal site in NE Italy is inverted to examine the applicability and robustness of the proposed approach on surface wave data. Furthermore, the performance of DSA is compared against that of GA by real data to further evaluate scores of the inverse procedure described here. Simulation results from both synthetic and actual field data demonstrate that differential search algorithm (DSA) applied to nonlinear inversion of surface wave data should be considered good not only in terms of the accuracy but also in terms of the convergence speed. The great advantages of DSA are that the algorithm is simple, robust and easy to implement. Also there are fewer control parameters to tune.

  16. 4D-DSA and 4D fluoroscopy: preliminary implementation

    Science.gov (United States)

    Mistretta, C. A.; Oberstar, E.; Davis, B.; Brodsky, E.; Strother, C. M.

    2010-04-01

    We have described methods that allow highly accelerated MRI using under-sampled acquisitions and constrained reconstruction. One is a hybrid acquisition involving the constrained reconstruction of time dependent information obtained from a separate scan of longer duration. We have developed reconstruction algorithms for DSA that allow use of a single injection to provide the temporal data required for flow visualization and the steady state data required for construction of a 3D-DSA vascular volume. The result is time resolved 3D volumes with typical resolution of 5123 at frame rates of 20-30 fps. Full manipulation of these images is possible during each stage of vascular filling thereby allowing for simplified interpretation of vascular dynamics. For intravenous angiography this time resolved 3D capability overcomes the vessel overlap problem that greatly limited the use of conventional intravenous 2D-DSA. Following further hardware development, it will be also be possible to rotate fluoroscopic volumes for use as roadmaps that can be viewed at arbitrary angles without a need for gantry rotation. The most precise implementation of this capability requires availability of biplane fluoroscopy data. Since the reconstruction of 3D volumes presently suppresses the contrast in the soft tissue, the possibility of using these techniques to derive complete indications of perfusion deficits based on cerebral blood volume (CBV), mean transit time (MTT) and time to peak (TTP) parameters requires further investigation. Using MATLAB post-processing, successful studies in animals and humans done in conjunction with both intravenous and intra-arterial injections have been completed. Real time implementation is in progress.

  17. Chronic thromboembolic pulmonary hypertension: diagnostic impact of multislice-CT and selective pulmonary-DSA; Chronische thromboembolische pulmonale Hypertonie: diagnostische Wertigkeit von Mehrschicht-CT und selektiver Pulmonalis-DSA

    Energy Technology Data Exchange (ETDEWEB)

    Pitton, M.B.; Kemmerich, G.; Herber, S.; Schweden, F.; Thelen, M. [Mainz Univ. (Germany). Klinik fuer Radiologie; Mayer, E. [Mainz Univ. (Germany). Klinik fuer Herz-, Thorax- und Gefaesschirurgie

    2002-04-01

    Purpose: To evaluate the diagnostic impact of multislice-CT and selective pulmonary DSA in chronic thromboembolic pulmonary hypertension (CTEPH). Methods: 994 vessel segments of 14 consecutive patients with CTEPH were investigated with multislice-CT (slice thickness 3 mm, collimation 2.5 mm, reconstruction intervall 2 mm) and selective pulmonary DSA posterior-anterior, 45 oblique, and lateral projection. Analysis was performed by 2 investigators independently for CT and DSA. Diagnostic criteria were occlusions and non-occlusive changes like webs and bands, irregularities of the vessel wall, diameter reduction and thromboembolic depositions at different levels from central pulmonary arteries to subsegmental arteries. Reference diagnosis was made by synopsis of CT and DSA by consensus. Results: Concerning patency CT and DSA showed concordant findings overall in 88.9%, 92.9% for segmental arteries and 85.4% for subsegmental arteries. Concerning any thromboembolic changes, multislice-CT was significantly inferior to selective DSA (concordance 67.0% overall, 70.4% for segments and 63.6% for subsegments). Non-occlusive changes of the vessels were significantly underdiagnosed by CT (concordance of CT versus DSA: 23.1%). Conclusion: Multislice-CT and selective pulmonary DSA are equivalent for diagnosis of vessel occlusions at the level of segmental and subsegmental arteries. However, for visualisation of the non-occlusive thromboembolic changes of the vessel wall selective pulmonary DSA is still superior compared to multislice-CT. Multislice-CT and selective pulmonary DSA are complementary tools for diagnosis and treatment planning of chronic thromboembolic pulmonary hypertension (CTEPH). (orig.) [German] Fragestellung: Ueberpruefung der diagnostischen Aussage der Mehrschicht-CT im Vergleich zur selektiven Pulmonalis-DSA bei sehwerer thromboembolischer pulmonaler Hypertonie (CTEPH). Material und Methoden: Bei 14 konsekutiven Patienten mit CTPH wurden ein Mehrschicht-CT (SD

  18. Quantitative flow and velocity measurements of pulsatile blood flow with 4D-DSA

    Science.gov (United States)

    Shaughnessy, Gabe; Hoffman, Carson; Schafer, Sebastian; Mistretta, Charles A.; Strother, Charles M.

    2017-03-01

    Time resolved 3D angiographic data from 4D DSA provides a unique environment to explore physical properties of blood flow. Utilizing the pulsatility of the contrast waveform, the Fourier components can be used to track the waveform motion through vessels. Areas of strong pulsatility are determined through the FFT power spectrum. Using this method, we find an accuracy from 4D-DSA flow measurements within 7.6% and 6.8% RMSE of ICA PCVIPR and phantom flow probe validation measurements, respectively. The availability of velocity and flow information with fast acquisition could provide a more quantitative approach to treatment planning and evaluation in interventional radiology.

  19. Advanced CD-SEM metrology for qualification of DSA patterns using coordinated line epitaxy (COOL) process

    Science.gov (United States)

    Kato, Takeshi; Konishi, Junko; Ikota, Masami; Yamaguchi, Satoru; Seino, Yuriko; Sato, Hironobu; Kasahara, Yusuke; Azuma, Tsukasa

    2016-03-01

    Directed self-assembly (DSA) applying chemical epitaxy is one of the promising lithographic solutions for next generation semiconductor device manufacturing. Especially, DSA lithography using coordinated line epitaxy (COOL) process is obviously one of candidates which could be the first generation of DSA applying PS-b-PMMA block copolymer (BCP) for sub-15nm dense line patterning . DSA can enhance the pitch resolutions, and can mitigate CD errors to the values much smaller than those of the originally exposed guiding patterns. On the other hand, local line placement error often results in a worse value, with distinctive trends depending on the process conditions. To address this issue, we introduce an enhanced measurement technology of DSA line patterns with distinguishing their locations in order to evaluate nature of edge placement and roughness corresponding to individual pattern locations by using images of CD-SEM. Additionally correlations among edge roughness of each line and each space are evaluated and discussed. This method can visualize features of complicated roughness easily to control COOL process. As a result, we found the followings. (1) Line placement error and line placement roughness of DSA were slightly different each other depending on their relative position to the chemical guide patterns. (2) In middle frequency area of PSD (Power Spectral Density) analysis graphs, it was observed that shapes were sensitively changed by process conditions of chemical stripe guide size and anneals temperature. (3) Correlation coefficient analysis using PSD was able to clarify characteristics of latent defect corresponding to physical and chemical property of BCP materials.

  20. Benign Prostatic Hyperplasia: Cone-Beam CT in Conjunction with DSA for Identifying Prostatic Arterial Anatomy.

    Science.gov (United States)

    Wang, Mao Qiang; Duan, Feng; Yuan, Kai; Zhang, Guo Dong; Yan, Jieyu; Wang, Yan

    2017-01-01

    Purpose To describe findings in prostatic arteries (PAs) at digital subtraction angiography (DSA) and cone-beam computed tomography (CT) that allow identification of benign prostatic hyperplasia and to determine the value added with the use of cone-beam CT. Materials and Methods This retrospective single-institution study was approved by the institutional review board, and the requirement for written informed consent was waived. From February 2009 to December 2014, a total of 148 patients (mean age ± standard deviation, 70.5 years ± 14.5) underwent DSA of the internal iliac arteries and cone-beam CT with a flat-detector angiographic system before they underwent prostate artery embolization. Both the DSA and cone-beam CT images were evaluated by two interventional radiologists to determine the number of independent PAs and their origins and anastomoses with adjacent arteries. The exact McNemar test was used to compare the detection rate of the PAs and the anastomoses with DSA and with cone-beam CT. Results The PA anatomy was evaluated successfully by means of cone-beam CT in conjunction with DSA in all patients. Of the 296 pelvic sides, 274 (92.6%) had only one PA. The most frequent PA origin was the common gluteal-pudendal trunk with the superior vesicular artery in 118 (37.1%), followed by the anterior division of the internal iliac artery in 99 (31.1%), and the internal pudendal artery in 77 (24.2%) pelvic sides. In 67 (22.6%) pelvic sides, anastomoses to adjacent arteries were documented. The numbers of PA origins and anastomoses, respectively, that could be identified were significantly higher with cone-beam CT (301 of 318 [94.7%] and 65 of 67 [97.0%]) than with DSA (237 [74.5%] and 39 [58.2%], P Cone-beam CT provided essential information that was not available with DSA in 90 of 148 (60.8%) patients. Conclusion Cone-beam CT is a useful adjunctive technique to DSA for identification of the PA anatomy and provides information to help treatment planning during

  1. Defect source analysis of directed self-assembly process (DSA of DSA)

    Science.gov (United States)

    Rincon Delgadillo, Paulina; Harukawa, Ryota; Suri, Mayur; Durant, Stephane; Cross, Andrew; Nagaswami, Venkat R.; Van Den Heuvel, Dieter; Gronheid, Roel; Nealey, Paul

    2013-03-01

    As design rule shrinks, it is essential that the capability to detect smaller and smaller defects should improve. There is considerable effort going on in the industry to enhance Immersion Lithography using DSA for 14 nm design node and below. While the process feasibility is demonstrated with DSA, material issues as well as process control requirements are not fully characterized. The chemical epitaxy process is currently the most-preferred process option for frequency multiplication and it involves new materials at extremely small thickness. The image contrast of the lamellar Line/Space pattern at such small layer thickness is a new challenge for optical inspection tools. In this investigation, the focus is on the capability for optical inspection systems to capture DSA unique defects such as dislocations and disclination clusters over the system and wafer noise. The study is also extended to investigate wafer level data at multiple process steps and determining contribution from each process step and materials using `Defect Source Analysis' methodology. The added defect pareto and spatial distributions of added defects at each process step are discussed.

  2. Clinical evaluation of stereoscopic DSA for vascular lesions

    OpenAIRE

    大川,元臣; 児島, 完治; 影山,淳一; 日野, 一郎; 高島, 均; 玉井,豊理; 田邉,正忠; 大本, 尭史; 植田, 清隆; 藤原, 敬

    1989-01-01

    Seventy-one series of stereoscopic DSA utilized on thirty-nine patients with intracranial vascular lesions were evaluated by comparison with subtracted magnified angiograms or independently. All stereoscopic series had good or fairly good stereoscopic quality. Stereoscopic DSA was useful in the preoperative stereoscopic vascular analysis of vascular lesions such as aneurysms, arteriovenous malformations, cartotid-cavernous fistulas, obstructive or stenotic vascular lesions and vascular elonga...

  3. Analysis of the self-assembling and the defect annihilation processes in DSA using meso-scale simulation

    Science.gov (United States)

    Morita, Hiroshi; Norizoe, Yuki

    2015-03-01

    Recently, directed self-assembly (DSA) method is focused on as a next generation lithography technique. We performed the DPD simulations to analyze the self-assembling process of block copolymer in DSA using OCTA (in detail, see http://octa.jp) system. Using DPD simulation, we can obtain the phase separated structures at each moment consisted by block copolymer chains. As those structures are consisted by polymer chains, an analysis can be done on those structures. In this paper, we study the dynamics of end particles in the defect annihilation process to understand the dynamics of self-assembling of block copolymer in DSA. From our analysis, the end particles moves in advance than the change of domain structure in the defect annihilation process.

  4. [Affine transformation-based automatic registration for peripheral digital subtraction angiography (DSA)].

    Science.gov (United States)

    Kong, Gang; Dai, Dao-Qing; Zou, Lu-Min

    2008-07-01

    In order to remove the artifacts of peripheral digital subtraction angiography (DSA), an affine transformation-based automatic image registration algorithm is introduced here. The whole process is described as follows: First, rectangle feature templates are constructed with their centers of the extracted Harris corners in the mask, and motion vectors of the central feature points are estimated using template matching technology with the similarity measure of maximum histogram energy. And then the optimal parameters of the affine transformation are calculated with the matrix singular value decomposition (SVD) method. Finally, bilinear intensity interpolation is taken to the mask according to the specific affine transformation. More than 30 peripheral DSA registrations are performed with the presented algorithm, and as the result, moving artifacts of the images are removed with sub-pixel precision, and the time consumption is less enough to satisfy the clinical requirements. Experimental results show the efficiency and robustness of the algorithm.

  5. Digital subtraction angiography - investigations concerning contrast medium dosage, radiation dose, and diagnostic value of DSA in pediatric cardiology

    Energy Technology Data Exchange (ETDEWEB)

    Pfefferkorn, J.R.; Hilgenberg, F.; Loeser, H.; Wehefritz, A.; Kronholz, H.L.

    1986-01-01

    The investigations reported have been carried out by application of an average radiation dose or sometimes of a higher dose. This allowed a high-contrast imaging for exact diagnosis of many vitium also with considerably reduced contrast medium. Further studies are planned in order to show the limits of radiation dose reduction for DSA. A dose reduction is expected to require an increase in contrast medium dosage. DSA is not expected to replace catheterized examination, but is shown to be a useful method for pediatric cardiology, especially for patients where morphological aspects have to be clarified, or contractility conditions. (orig./SHA).

  6. Template affinity role in CH shrink by DSA planarization

    Science.gov (United States)

    Tiron, R.; Gharbi, A.; Pimenta Barros, P.; Bouanani, S.; Lapeyre, C.; Bos, S.; Fouquet, A.; Hazart, J.; Chevalier, X.; Argoud, M.; Chamiot-Maitral, G.; Barnola, S.; Monget, C.; Farys, V.; Berard-Bergery, S.; Perraud, L.; Navarro, C.; Nicolet, C.; Hadziioannou, G.; Fleury, G.

    2015-03-01

    Density multiplication and contact shrinkage of patterned templates by directed self-assembly (DSA) of block copolymers (BCP) stands out as a promising alternative to overcome the limitations of conventional lithography. The main goal of this paper is to investigate the potential of DSA to address contact and via levels patterning with high resolution by performing either CD shrink or contact multiplication. Different DSA processes are benchmarked based on several success criteria such as: CD control, defectivity (missing holes) as well as placement control. More specifically, the methodology employed to measure DSA contact overlay and the impact of process parameters on placement error control is detailed. Using the 300mm pilot line available in LETI and Arkema's materials, our approach is based on the graphoepitaxy of PS-b-PMMA block copolymers. Our integration scheme, depicted in figure 1, is based on BCP self-assembly inside organic hard mask guiding patterns obtained using 193i nm lithography. The process is monitored at different steps: the generation of guiding patterns, the directed self-assembly of block copolymers and PMMA removal, and finally the transfer of PS patterns into the metallic under layer by plasma etching. Furthermore, several process flows are investigated, either by tuning different material related parameters such as the block copolymer intrinsic period or the interaction with the guiding pattern surface (sidewall and bottom-side affinity). The final lithographic performances are finely optimized as a function of the self-assembly process parameters such as the film thickness and bake (temperature and time). Finally, DSA performances as a function of guiding patterns density are investigated. Thus, for the best integration approach, defect-free isolated and dense patterns for both contact shrink and multiplication (doubling and more) have been achieved on the same processed wafer. These results show that contact hole shrink and

  7. Real-world experimentation of distributed DSA network algorithms

    DEFF Research Database (Denmark)

    Tonelli, Oscar; Berardinelli, Gilberto; Tavares, Fernando Menezes Leitão;

    2013-01-01

    such as a dynamic propagation environment, human presence impact and terminals mobility. This chapter focuses on the practical aspects related to the real world-experimentation with distributed DSA network algorithms over a testbed network. Challenges and solutions are extensively discussed, from the testbed design...... of the available spectrum by nodes in a network, without centralized coordination. While proof-of-concept and statistical validation of such algorithms is typically achieved by using system level simulations, experimental activities are valuable contributions for the investigation of particular aspects...... to the setup of experiments. A practical example of experimentation process with a DSA algorithm is also provided....

  8. The use of eDR-71xx for DSA defect review and automated classification

    Science.gov (United States)

    Pathangi, Hari; Van Den Heuvel, Dieter; Bayana, Hareen; Bouckou, Loemba; Brown, Jim; Parisi, Paolo; Gosain, Rohan

    2015-03-01

    The Liu-Nealey (LiNe) chemo-epitaxy Directed Self Assembly flow has been screened thoroughly in the past years in terms of defects. Various types of DSA specific defects have been identified and best known methods have been developed to be able to get sufficient S/N for defect inspection to help understand the root causes for the various defect types and to reduce the defect levels to prepare the process for high volume manufacturing. Within this process development, SEM-review and defect classification play a key role. This paper provides an overview of the challenges that DSA brings also in this metrology aspect and we will provide successful solutions in terms of making the automated defect review. In addition, a new Real Time Automated Defect Classification (RT-ADC) will be introduced that can save up to 90% in the time required for manual defect classification. This will enable a much larger sampling for defect review, resulting in a better understanding of signatures and behaviors of various DSA specific defect types, such as dislocations, 1-period bridges and line wiggling.

  9. Overview and development of EDA tools for integration of DSA into patterning solutions

    Science.gov (United States)

    Torres, J. Andres; Fenger, Germain; Khaira, Daman; Ma, Yuansheng; Granik, Yuri; Kapral, Chris; Mitra, Joydeep; Krasnova, Polina; Ait-Ferhat, Dehia

    2017-03-01

    Directed Self-Assembly is the method by which a self-assembly polymer is forced to follow a desired geometry defined or influenced by a guiding pattern. Such guiding pattern uses surface potentials, confinement or both to achieve polymer configurations that result in circuit-relevant topologies, which can be patterned onto a substrate. Chemo, and grapho epitaxy of lines and space structures are now routinely inspected at full wafer level to understand the defectivity limits of the materials and their maximum resolution. In the same manner, there is a deeper understanding about the formation of cylinders using grapho-epitaxy processes. Academia has also contributed by developing methods that help reduce the number of masks in advanced nodes by "combining" DSA-compatible groups, thus reducing the total cost of the process. From the point of view of EDA, new tools are required when a technology is adopted, and most technologies are adopted when they show a clear cost-benefit over alternative techniques. In addition, years of EDA development have led to the creation of very flexible toolkits that permit rapid prototyping and evaluation of new process alternatives. With the development of high-chi materials, and by moving away of the well characterized PS-PMMA systems, as well as novel integrations in the substrates that work in tandem with diblock copolymer systems, it is necessary to assess any new requirements that may or may not need custom tools to support such processes. Hybrid DSA processes (which contain both chemo and grapho elements), are currently being investigated as possible contenders for sub-5nm process techniques. Because such processes permit the re-distribution of discontinuities in the regular arrays between the substrate and a cut operation, they have the potential to extend the number of applications for DSA. This paper illustrates the reason as to why some DSA processes can be supported by existing rules and technology, while other processes

  10. Real-world experimentation of distributed DSA network algorithms

    DEFF Research Database (Denmark)

    Tonelli, Oscar; Berardinelli, Gilberto; Tavares, Fernando Menezes Leitão

    2013-01-01

    of the available spectrum by nodes in a network, without centralized coordination. While proof-of-concept and statistical validation of such algorithms is typically achieved by using system level simulations, experimental activities are valuable contributions for the investigation of particular aspects...... such as a dynamic propagation environment, human presence impact and terminals mobility. This chapter focuses on the practical aspects related to the real world-experimentation with distributed DSA network algorithms over a testbed network. Challenges and solutions are extensively discussed, from the testbed design......The problem of spectrum scarcity in uncoordinated and/or heterogeneous wireless networks is the key aspect driving the research in the field of flexible management of frequency resources. In particular, distributed dynamic spectrum access (DSA) algorithms enable an efficient sharing...

  11. Secure Order-Specified Multisignature Scheme Based on DSA

    Institute of Scientific and Technical Information of China (English)

    YANG Muxiang; SU Li; LI Jun; HONG Fan

    2006-01-01

    In multisignature schemes signers can sign either in a linear order or not in any specified order, but neither of them is adequate in some scenarios where require mixture using of orderless and ordered multisignature. Most order-specified multisignatures specified the orders as linear ones. In this paper, we proposed an order-specified multisignature scheme based on DSA secure against active insider attack. To our knowledge, it is the first order-specified multisignature scheme based on DSA signature scheme, in which signers can sign in flexible order represented by series-parallel graphs. In the multisignature scheme verification to both signers and signing order are available. The security of the scheme is proved by reduce to an identification scheme that is proved have some concrete security. The running time of verifying a signature is comparable to previous schemes while the running time of multisignature generation and the space needed is less than those schemes.

  12. Design strategy for integrating DSA via patterning in sub-7 nm interconnects

    Science.gov (United States)

    Karageorgos, Ioannis; Ryckaert, Julien; Tung, Maryann C.; Wong, H.-S. P.; Gronheid, Roel; Bekaert, Joost; Karageorgos, Evangelos; Croes, Kris; Vandenberghe, Geert; Stucchi, Michele; Dehaene, Wim

    2016-03-01

    In recent years, major advancements have been made in the directed self-assembly (DSA) of block copolymers (BCPs). As a result, the insertion of DSA for IC fabrication is being actively considered for the sub-7nm nodes. At these nodes the DSA technology could alleviate costs for multiple patterning and limit the number of litho masks that would be required per metal layer. One of the most straightforward approaches for DSA implementation would be for via patterning through templated DSA, where hole patterns are readily accessible through templated confinement of cylindrical phase BCP materials. Our in-house studies show that decomposition of via layers in realistic circuits below the 7nm node would require at least many multi-patterning steps (or colors), using 193nm immersion lithography. Even the use of EUV might require double patterning in these dimensions, since the minimum via distance would be smaller than EUV resolution. The grouping of vias through templated DSA can resolve local conflicts in high density areas. This way, the number of required colors can be significantly reduced. For the implementation of this approach, a DSA-aware mask decomposition is required. In this paper, our design approach for DSA via patterning in sub-7nm nodes is discussed. We propose options to expand the list of DSA-compatible via patterns (DSA letters) and we define matching cost formulas for the optimal DSA-aware layout decomposition. The flowchart of our proposed approach tool is presented.

  13. Comparison of remnant size in embolized intracranial aneurysms measured at follow-up with DSA and MRA

    Energy Technology Data Exchange (ETDEWEB)

    Serafin, Zbigniew; Strzesniewski, Piotr; Lasek, Wladyslaw [Nicolaus Copernicus University, Department of Radiology and Diagnostic Imaging, Collegium Medicum, Bydgoszcz (Poland); Beuth, Wojciech [University of Humanities and Economics in Wloclawek, Faculty of Health Sciences, Wloclawek (Poland)

    2012-12-15

    The possibility of recanalization and the need for retreatment are the most important limitations of intracranial aneurysm embolization. The purpose of the study was to compare the size of aneurysm remnants measured at follow-up with three-dimensional digital subtracted angiography (3D-DSA) and magnetic resonance angiography (MRA). Twenty-six aneurysms were found incompletely occluded in 72 consecutively examined patients at a follow-up after 3 months. The diameters and volume of aneurysm remnants were compared between 3D-DSA, time-of-flight MRA (TOF-MRA), contrast-enhanced TOF-MRA (CE-TOF-MRA), and contrast-enhanced MRA (CE-MRA) at 1.5 T. There was a significant correlation between remnant volumes calculated based on 3D-DSA and all MRA modalities. The intraobserver variability of the measurements ranged from 3.4 to 4.1 % and the interobserver variability from 5.8 to 7.3 %. There were no significant differences in the variability between the techniques. The mean residual filling volume ranged from 16.3 {+-} 19.0 mm{sup 3} in TOF-MRA to 30.5 {+-} 44.6 mm{sup 3} in 3D-DSA (P < 0.04). Significant differences were found in the volumes measured with 3D-DSA and CE-MRA as compared to TOF-MRA and CE-TOF-MRA (P < 0.01). There was a moderate significant correlation between the residual filling and the relative error of measurement in the case of TOF-MRA and CE-TOF-MRA. TOF-MRA seems to underestimate the size of aneurysm remnants detected at follow-up and should not be used as a sole imaging method to decide on re-embolization. (orig.)

  14. Evaluation of angiographic computed tomography in the follow-up after endovascular treatment of cerebral aneurysms - a comparative study with DSA and TOF-MRA

    Energy Technology Data Exchange (ETDEWEB)

    Buhk, Jan-Hendrik; Kallenberg, Kai [University of Goettingen, Department of Neuroradiology, Goettingen (Germany)]|[University of Goettingen, MR-Research in Neurology and Psychiatry, Goettingen (Germany); Mohr, Alexander; Knauth, Michael [University of Goettingen, Department of Neuroradiology, Goettingen (Germany); Dechent, Peter [University of Goettingen, MR-Research in Neurology and Psychiatry, Goettingen (Germany)

    2009-02-15

    Following coil embolization of intracranial aneurysms, many centers perform at least one digital subtraction angiography (DSA) continuing with time-of-flight magnetic resonance angiography (TOF-MRA). Angiographic computed tomography (ACT) provides high-resolution data from a rotational acquisition of a c-arm-mounted flat panel detector. This study evaluates possible advantages of applying ACT in aneurysm follow-up. In 22 patients DSA examinations with a rotational acquisition were performed. Rotational data were processed into an isotropic high-resolution volume. TOF-MRA was performed the day before DSA. Three experienced neuroradiologists performed a rating of the occlusion rate and a subjective method comparison. Weighted {kappa} statistics were calculated to assess the level of interobserver agreement. Compared to DSA, the diagnostic value of ACT as well as of TOF-MRA was rated to be inferior, although the sensitivity of detecting residual necks was higher with both techniques. Compared to TOF-MRA, ACT achieves favorable ratings only in aneurysms after stent-remodeling. Interobserver agreement was high for all techniques. Ratings of the occlusion rate correlated highly between all observers (r > 0.85, p < 0.001, respectively). In selected patients ACT can add valuable diagnostic information to DSA. TOF-MRA remains a highly sensitive method for aneurysm follow-up. (orig.)

  15. Diagnostic Value of 64-slice CTA in Detection of Intracranial Aneurysm in Patients with SAH and Comparison of the CTA Results with 2D-DSA and Intraoperative Findings

    Directory of Open Access Journals (Sweden)

    Elif Ergun

    2011-03-01

    Full Text Available Objective: To prospectively evaluate the diagnostic value of 64-slice CTA in detecting intracranial aneurysms and to compare it with 2D-DSA and/or intra-operative findings.Material and Methods: 37 cases with SAH according to unenhanced cranial CT were included in the study. A 64-slice CTA was performed to all cases immediately after the nonenhanced cranial CT. DSA was performed in 24-48 hours following CTA. CT images were reviewed by two radiologists experienced in CT vascular imaging. The DSA reader was the angiographer who performed the DSA. The results of the CTA were compared with the DSA results and/or intraoperative findings in order to determine the diagnostic efficacy of CTA in detecting intracranial aneurysms. Results: Sensitivity, specificity, positive predictive value, negative predictive value and accuracy of CTA in detecting aneurysms were 92.8%, 83.3%, 96.2%, 71.4% and 91.2% respectively. The diagnostic value of CTA in detecting intracranial aneurysms was found to be equal to DSA by Mcnemar test. Conclusion: CTA is invaluable in detecting intracranial aneurysms. It may be used as a first line modality in SAH, and DSA may be reserved for patients with negative or equivocal CTA results.

  16. Coincident high-velocity DSA lifetime measurements on excited states of Si isotopes and stopping power investigations

    NARCIS (Netherlands)

    Scherpenzeel, D.E.C.; Engelbertink, G.A.P.; Aarts, H.J.M.; Poel, C.J. van der; Arciszewski, H.F.R.

    1980-01-01

    Mean lives of low-lying states of 28Si, 29Si and 30Si have been measured with the coincident high-velocity DSA method by 28Si bombardment of 2H, 3H and 4He targets. The recoils with an initial velocity of about 0.048c are slowed down in Mg, Cu, Ag and Au. The emitted γ-ray Doppler patterns are obser

  17. DSA by means of fine-needle puncture for excluding vascular complications in haemodialysis shunts

    Energy Technology Data Exchange (ETDEWEB)

    Alart, I.P.; Merk, J.; Eichner, H.

    1985-06-01

    The article on hand presents the experience gained with examinations of Cimino haemodialysis shunts using digital substraction angiography (DSA). Angiographic results after arterial and venous fine-needle puncture show - particularly in arterial DSA - the advantage of excellent contrasting of the afferent arterial vessel, of the arterio-venous anastomosis and of the venous return while allowing safe diagnosis. This examination procedure is low in complications for the patient, is suitable for outpatients and has numerous advantages over transvenous shunt DSA.

  18. IV DSA in the diagnosis and follow-up of dissection of the thoracic aorta

    Energy Technology Data Exchange (ETDEWEB)

    Hendrickx, P.; Luska, G.; Laas, J.; Haverich, A.

    1986-05-01

    Intravenous DSA was performed in 53 patients with suspected dissection of the thoracic aorta and in 13 patients following surgery for aortic dissection. In 36 patients, the suspected diagnosis could be excluded definitely and, in 14 cases out of 17, a dissection was correctly diagnosed. All 11 type B dissections were correctly diagnosed. Of six type A dissections, only three were adequately demonstrated by IV DSA. In type B dissections, IV DSA is reliable, but in type A dissection with massive aortic insufficiency or pericardial tamponade the findings are not reliable. In all 13 patients who had surgery for dissection, IV DSA proved suitable for showing the anastomosis and progress of the disease.

  19. Calibration and application of a DSA Compact model for graphoepitaxy hole processes using contour-based metrology

    Science.gov (United States)

    Fenger, Germain; Burbine, Andrew; Torres, J. Andres; Ma, Yuansheng; Granik, Yuri; Krasnova, Polina; Vandenberghe, Geert; Gronheid, Roel; Bekaert, Joost

    2014-10-01

    Significant interest from the integrated circuit (IC) industry has been placed on directed selfassembly (DSA) for sub 10nm nodes. DSA is being considered as a cost reduction complementary process to multiple patterning (MP) and an enabler of new technology nodes. However, to realize the potential of this technology, it is essential to look holistically at the necessary infrastructure from the point of view of materials, hardware, software, process integration and design methodologies which enable its deployment in large volume manufacturing. One key aspect in enabling DSA processes is the ability to mirror functionality of full chip mask synthesis and verification methods of existing tools used in production. One of those critical components is the ability to accurately model the placement of the target phases in the DSA process with a given mask shape, as well as determining the conditions at which unwanted phase transitions start to occur. Self-consistent field theory and Monte Carlo1 simulators have the capability to probe and explore the mechanisms driving the different phases of a diblock copolymer system. While such methods are appropriate to study the nature of the self-assembly process, they are computationally expensive and they cannot be used to perform mask synthesis operations nor full chip verification. The nature of a compact model is to make a series of approximations allowing a simpler description of the problem in a way that the phenomena of interest can be sufficiently captured even if it is at the expense of its generality. In this case we focus our effort in establishing the minimum set of conditions that a compact model for the manufacture of contact holes using a grapho epitaxy process for a PS-PMMA diblock copolymer system needs. The processes uses etched short trenches as guiding patterns in which the vertical DSA cylinders are formed. By focusing in the phase of interest (i.e., cylinder forming conditions), it is possible to reformulate the

  20. Correlation of the Appearances of DSA with VEGF Expression and Its Clinical Significance in Patients with Primary Hepatocellular Carcinoma

    Institute of Scientific and Technical Information of China (English)

    CHEN Fangman; JIAO Xudong; DU Fang

    2006-01-01

    Objective: To investigate the relationship between the appearances of digital subtraction angiography (DSA) and the serum level of vascular endothelial growth factor (VEGF) in patients with primary hepatocellular carcinoma (HCC). Methods: 24 HCC patients, 30 times DSA were examined, serum VEGF level was measured with the quantitative enzyme linked immunosorbent assay (ELISA) in patients and healthy control subjects in this study. Results: Among DSA for 24 patients with HCC, 18 of 24 cases showed hepatic artery blood supply of tumor. Four of 24 cases showed portal vein blood supply of tumor,1 of 24 cases showed superior mesenteric artery blood supply of tumor and artery-venous shunt formation, and there was no blood supply to tumor in one case. Serum VEGF level in HCC[(χ+s)194.5±14.2] ng/L was significant elevated to those in patients comparing with those of the normal controls (132.4±47.9)ng/L and marked differences (P<0.01). Conclusion: During the cases for plenty blood supply or arteryvenous shunt formation in patients with HCC, serum VEGF level markedly elevated in the patients of HCC. VEGF expression was significantly related to intrahepatic dissemination, recurrence and metastasis in patients with HCC.

  1. 34 CFR 367.11 - What assurances must a DSA include in its application?

    Science.gov (United States)

    2010-07-01

    ...) and (b), and consistent with 34 CFR 364.28, the DSA will seek to incorporate into and describe in the... section 704 of the Act and subpart C of 34 CFR part 364; and (g) The applicant has been designated by the... 34 Education 2 2010-07-01 2010-07-01 false What assurances must a DSA include in its...

  2. SU-E-I-26: Estimation of Micro-Angiographic Fluoroscope (MAF) Gain Settings for Digital Subtraction Angiography (DSA) Based on the Fluoroscopic Exposure.

    Science.gov (United States)

    Ionita, C; Loughran, B; Nagesh, S Setlur; Jain, A; Bednarek, D; Rudin, S

    2012-06-01

    The MAF is a new high-resolution detector which is being clinically evaluated in neuro-vascular procedures. The detector contains a large-dynamic-range, high-sensitivity light image intensifier with variable gain. Since the MAF is a research prototype only partially integrated with the clinical system, x-ray technique parameters must be set manually. To improve workflow we developed an automatic method to estimate and set the proper LII voltage (MAF gain) for DSA acquisition based on the fluoroscopic parameters. The detector entrance exposure (XD) can be written as the x-ray tube output exposure (Xo) times an object attenuation factor and an inverse-square correction. If the object attenuation, scatter and distances are unchanged and the effect of x-ray kVp changes are neglected, then the DSA XD can be expressed as the ratio of Xo(DSA)/Xo(Fluoroscopy) multiplied with XD(fluoroscopy). We measured Xo for fluoroscopy and DSA for mAs and kVp ranges appropriate to neuro- vascular interventions and fit the data with a 2D function. To estimate the XD(Fluoroscopy) we derived a curve of XD versus LII-voltage for a mid- dynamic-range average pixel gray-level. Since the MAF system during clinical fluoroscopy automatically adjusts the LII voltage until the desired gray-level value is achieved, by reading that voltage we can estimate the XD(Fluoroscopy). Using the 2D-fit function, Xo(DSA) is automatically calculated for the kVp and mA values set and XD(DSA) can be estimated using the relation above. Using the inverse LII calibration curve, the proper LII-voltage can be determined for the desired average gray-level. The algorithm was implemented and evaluated in thirty-two in-vivo DSA runs on rabbits. The proper LII voltage was selected in all cases with no failures. Using the fluoroscopic LII gain setting to determine the appropriate DSA setting can greatly improve the workflow in clinical evaluations of the MAF. NIH Grants R01-EB008425, R01-EB002873 and an equipment grant from

  3. DSA template optimization for contact layer in 1D standard cell design

    Science.gov (United States)

    Xiao, Zigang; Du, Yuelin; Tian, Haitong; Wong, Martin D. F.; Yi, He; Wong, H.-S. Philip

    2014-03-01

    At the 7 nm technology node, the contact layers of integrated circuits (IC) are too dense to be printed by single exposure lithography. Block copolymer directed self-assembly (DSA) has shown its advantage in contact/via patterning with high throughput and low cost. To pattern contacts with DSA, guiding templates are usually printed first with conventional lithography, e.g., 193 nm immersion lithography (193i) that has a coarser pitch resolution. Contact holes are then patterned with DSA process. The guiding templates play the role of controlling the DSA patterns inside, which have a finer resolution than the templates. The DSA contact pitch depends on the chemical property of block copolymer and it can be adjusted within a certain range under strong lateral confinement to deviate from the natural pitch. As a result, different patterns can be obtained through different parameters. Although the guiding template shapes can be arbitrary, the overlay accuracy of the contact holes patterned are different and largely depend on the templates. Thus, the guiding templates that have tolerable variations are considered as feasible, and those have large overlays are considered as infeasible. To pattern the contact layer in a layout with DSA technology, we must ensure that all the DSA templates in the layout are feasible. However, the original layout may not be designed in a DSA-friendly way. Moreover, the routing process may introduce contacts that can only be patterned by infeasible templates. In this paper, we propose an optimization algorithm that optimize the contact layer for DSA patterning in 1D standard cell design. In particular, the algorithm modifies the layout via wire permutation technique to redistribute the contacts such that the use of infeasible templates is avoided and the feasible patterns that with better overlay control are favored. The experimental result demonstrate the ability of the proposed algorithm in helping to reduce the design and manufacturing

  4. Comparative imaging study in ultrasound, MRI, CT, and DSA using a multimodality renal artery phantom

    Energy Technology Data Exchange (ETDEWEB)

    King, Deirdre M.; Fagan, Andrew J.; Moran, Carmel M.; Browne, Jacinta E. [Medical Ultrasound Physics and Technology Group, School of Physics, Dublin Institute of Technology, Dublin 8 (Ireland); Centre for Advanced Medical Imaging (CAMI), St James' s Hospital, Dublin 8 (Ireland); Department of Medical Physics, University of Edinburgh, Edinburgh EH16 4TJ (United Kingdom); Medical Ultrasound Physics and Technology Group, School of Physics, Dublin Institute of Technology, Dublin 8 (Ireland)

    2011-02-15

    Purpose: A range of anatomically realistic multimodality renal artery phantoms consisting of vessels with varying degrees of stenosis was developed and evaluated using four imaging techniques currently used to detect renal artery stenosis (RAS). The spatial resolution required to visualize vascular geometry and the velocity detection performance required to adequately characterize blood flow in patients suffering from RAS are currently ill-defined, with the result that no one imaging modality has emerged as a gold standard technique for screening for this disease. Methods: The phantoms, which contained a range of stenosis values (0%, 30%, 50%, 70%, and 85%), were designed for use with ultrasound, magnetic resonance imaging, x-ray computed tomography, and x-ray digital subtraction angiography. The construction materials used were optimized with respect to their ultrasonic speed of sound and attenuation coefficient, MR relaxometry (T{sub 1},T{sub 2}) properties, and Hounsfield number/x-ray attenuation coefficient, with a design capable of tolerating high-pressure pulsatile flow. Fiducial targets, incorporated into the phantoms to allow for registration of images among modalities, were chosen to minimize geometric distortions. Results: High quality distortion-free images of the phantoms with good contrast between vessel lumen, fiducial markers, and background tissue to visualize all stenoses were obtained with each modality. Quantitative assessments of the grade of stenosis revealed significant discrepancies between modalities, with each underestimating the stenosis severity for the higher-stenosed phantoms (70% and 85%) by up to 14%, with the greatest discrepancy attributable to DSA. Conclusions: The design and construction of a range of anatomically realistic renal artery phantoms containing varying degrees of stenosis is described. Images obtained using the main four diagnostic techniques used to detect RAS were free from artifacts and exhibited adequate contrast

  5. CT angiography with three-dimensional techniques for the early diagnosis of intracranial aneurysms. Comparison with intra-arterial DSA and the surgical findings

    Energy Technology Data Exchange (ETDEWEB)

    Karamessini, Maria T.; Kagadis, George C.; Petsas, Theodore; Karnabatidis, Dimitrios; Konstantinou, Dimitrios; Sakellaropoulos, George C.; Nikiforidis, George C.; Siablis, Dimitrios E-mail: siablis@med.upatras.gr

    2004-03-01

    Introduction: Cerebral CT angiography (CTA) is an established method applied to both the detection and treatment planning of intracranial aneurysms. The aim of our study was to compare CTA and digital subtraction angiography (DSA) findings with the surgical results mainly in patients with acute SAH and to evaluate the clinical usefulness of CTA. Materials and methods: During the last 2 years, 82 consecutive patients were admitted under clinical symptoms and signs suggestive of harboring an intracranial aneurysm. CT angiography performed immediately afterwards the plain CT, while DSA was performed within the first 48 h of admission. All aneurysms detected were confirmed during surgery or endovascular embolization. Repeat DSA was performed in all patients having both the initial CTA and the DSA 15 days after the onset of symptoms negative. CT angiograms and conventional angiographies were studied by a consensus of two radiologists for each technique, who performed aneurysm detection, morphological features characterization and evaluation of the technique. Results: Surgical or/and endovascular treatment was performed in 45 patients and 53 aneurysms were confirmed. Using 3D-CT angiography, we detected 47 aneurysms in 42 patients. Conventional angiography depicted 43 aneurysms in 39 patients. The sensitivity of CTA for the detection of all aneurysms versus surgery was 88.7%, the specificity 100%, the positive predictive value (PPV) 100%, the negative predictive value (NPV) 80.7% and the accuracy 92.3%. Accordingly, the sensitivity of DSA was 87.8%, the specificity 98%, the PPV 97.7%, the NPV 89.1% and the accuracy 92.9%. Considering aneurysms {>=}3 mm, CTA showed a sensitivity ranging from 93.3 to 100%, equal to that of DSA. Conclusion: Cerebral CT angiography has an equal sensitivity to DSA in the detection of intracranial aneurysms >3 mm. It has also 100% detection rate in AcoA and MCA bifurcation aneurysms, while some locations, like posterior communicating artery

  6. DSA patterning options for FinFET formation at 7nm node

    Science.gov (United States)

    Liu, Chi-Chun C.; Franke, Elliott; Lie, Fee Li; Sieg, Stuart; Tsai, Hsinyu; Lai, Kafai; Truong, Hoa; Farrell, Richard; Somervell, Mark; Sanders, Daniel; Felix, Nelson; Guillorn, Michael; Burns, Sean; Hetzer, David; Ko, Akiteru; Arnold, John; Colburn, Matthew

    2016-03-01

    Several 27nm-pitch directed self-assembly (DSA) processes targeting fin formation for FinFET device fabrication are studied in a 300mm pilot line environment, including chemoepitaxy for a conventional Fin arrays, graphoepitaxy for a customization approach and a hybrid approach for self-aligned Fin cut. The trade-off between each DSA flow is discussed in terms of placement error, Fin CD/profile uniformity, and restricted design. Challenges in pattern transfer are observed and process optimization are discussed. Finally, silicon Fins with 100nm depth and on-target CD using different DSA options with either lithographic or self-aligned customization approach are demonstrated.

  7. Survey of DSA-certified digital repositories : Report on the findings in a survey of all DSA-certified digital repositories on investments in and benefits of acquiring the Data Seal of Approval (DSA)

    NARCIS (Netherlands)

    Waterman, Kees-Jan; Sierman, Barbara

    2016-01-01

    The Data Seal of Approval (DSA) has been in use as a certification instrument for trustworthy digital repositories (TDRs) since 2010. By March 2016 some 50 repositories had applied successfully for the seal. Whereas some organizations and repositories have published about their own experiences in th

  8. 3D-CTA、DSA对颅内动脉瘤诊疗价值的对比%Comparative study of 3D-CTA and DSA in the diagnosis and treatment of intracranial aneurysms

    Institute of Scientific and Technical Information of China (English)

    李祥; 于如同; 范月超; 郭克勤

    2009-01-01

    Objective To compare the clinical value of three-dimensional digital subtraction angiography(3D-DSA), three-dimensional computed tomographic angiography (3D-CTA) and conventional DSA(2D-DSA) in the diagnosis and treatment of Intracranial aneurysms. Methods The data of 3D-DSA, 3D-CTA, 2D-DSA and operation of 32 patients with Intracranial aneurysms were reviewed, retrospectively. Results 35 aneurysms were detected by 3D-DSA and correlated well with microsurgical findings. The shape of the aneurysms, their neck size and their relationships to the parent vessels and other branches were depicted clearly, especially compared with images obtained by 3D-CTA and 2D-DSA. 33 aneurysms were detected by 3D-CTA. 32 aneurysms were detected by 2D-DSA. Aneurysms' body, neck, parent artery and the relationship between the aneurysms and surrounding structures (bone) were clearly and surely displayed by 3D-CTA. Conclusion 3D-CTA is a sensitivity and rapid and noninvasive method for detecting aneurysms. 3D-CTA can be the first choice for diagnosing Intracranial aneurysms without performing 2D-DSA. During CT for ruptured aneurysms, a negative 3D-CTA should be investigated further by 3D-DSA. 3D-DSA should be performed in cases of multiple intracranial aneurysms with complex shapes or very small size. 3D-DSA should be the "gold standard" for detecting intracranial aneurysms.%目的 评价3D-DSA、3D-CTA、2D-DSA在颅内动脉瘤诊疗中的作用.方法 回顾性分析32例动脉瘤患者3D-DSA、3D-CTA、2D-DSA和手术资料.结果 32例患者共35个动脉瘤(有3例患者为多发动脉瘤).3D-DSA能清楚显示所有动脉瘤的形态,准确判断3例多发动脉瘤中破裂的动脉瘤且手术顺利夹闭;3D-CTA检出33个,遗漏1个前交通动脉瘤及1个颈内动脉瘤;2D-DSA检出32个,遗漏2个前交通动脉瘤和1个大脑中动脉瘤.3D-DSA及3D-CTA在显示瘤颈上明显优于2D-DSA,3D-CTA可准确显示动脉瘤与相邻骨质结构关系.结论 3D~CTA是检查颅

  9. Electrochemical cell design for the impedance studies of chlorine evolution at DSA(®) anodes.

    Science.gov (United States)

    Silva, J F; Dias, A C; Araújo, P; Brett, C M A; Mendes, A

    2016-08-01

    A new electrochemical cell design suitable for the electrochemical impedance spectroscopy (EIS) studies of chlorine evolution on Dimensionally Stable Anodes (DSA(®)) has been developed. Despite being considered a powerful tool, EIS has rarely been used to study the kinetics of chlorine evolution at DSA anodes. Cell designs in the open literature are unsuitable for the EIS analysis at high DSA anode current densities for chlorine evolution because they allow gas accumulation at the electrode surface. Using the new cell, the impedance spectra of the DSA anode during chlorine evolution at high sodium chloride concentration (5 mol dm(-3) NaCl) and high current densities (up to 140 mA cm(-2)) were recorded. Additionally, polarization curves and voltammograms were obtained showing little or no noise. EIS and polarization curves evidence the role of the adsorption step in the chlorine evolution reaction, compatible with the Volmer-Heyrovsky and Volmer-Tafel mechanisms.

  10. [2011 Shanghai customer satisfaction report of DSA/X-ray equipment's after-service].

    Science.gov (United States)

    Li, Bin; Qian, Jianguo; Cao, Shaoping; Zheng, Yunxin; Xu, Zitian; Wang, Lijun

    2012-11-01

    To improve the manufacturer's medical equipment after-sale service, the fifth Shanghai zone customer satisfaction survey was launched by the end of 2011. The DSA/X-ray equipment was setup as an independent category for the first time. From the survey we can show that the DSA/X-ray equipment's CSI is higher than last year, the customer satisfaction scores of preventive maintenance and service contract are lower than others, and CSI of local brand is lower than imported brand.

  11. The Experimental Research on the Frameless Registration of DSA/CT Images

    Institute of Scientific and Technical Information of China (English)

    HUANG Yong-feng; LI Wen; ZENG Pei-feng; ZHAO Jun

    2006-01-01

    DSA images show vessels with clarity and CT images show bones distinctly. In this paper, we present an experimental research on the frameless registration of DSA/CT images based on localization algorithm. With four external markers, the vessels and bones in human brain can be integrated. The mean accuracy of simulated experiment is about 2.0 mm. The experiment proved that the 3D images composed cerebral anatomy and vasculature could help neurosurgeons perform accurate diagnosis and make right operation planning.

  12. The analysis of cerebro-vascular circulation time using digital subtraction angiography (DSA)

    Energy Technology Data Exchange (ETDEWEB)

    Han, D. G.; Kim, D. H.; Lee, H. K.; Kwon, K. H.; Kim, K. J. [Soonchunhyang University College of Medicine, Asan (Korea, Republic of)

    1986-10-15

    We analyzed the cerebral arterio-venous circulation time of 141 cases of cranial DSA in 136 patients, for the assessment of cerebral circulatory dynamics. IV-DSA was 111 cases, IA-DSA 30 cases. The results were as follows: 1. There was no significant difference in arterio-venous circulation time between IA-DSA and IV-DSA, if the disease pattern was not considered (P > 0.1). 2. Prolongation of arterio-venous circulation time was noted in the cases of cerebral (cerebellar) hemorrhage, subarachnoid hemorrhage, intracranial hematoma, brain abscess, acute stage of cerebra-vascular occlusive disease, acute stage of postoperative follow up, and acute stage of cerebral contusion (p > 0.05). 3. Compared the chronic stage of cerebra-vascular occlusive disease, postoperative follow up, and cerebral contusion with acute stage, significant decrement of arterio-venous circulation time was resulted (p > 0.05). 4. DSA was a useful modality for the assessment of circulatory dynamics, including measurement of arterio-venous circulation time.

  13. Clinical application of three-dimensional DSA combined with roadmap technique in diagnosis of cerebral vascular diseases%3D-DSA联合roadmap技术在脑血管疾病介入诊治中的应用价值

    Institute of Scientific and Technical Information of China (English)

    陈建华; 贺雄军; 段传志; 刘亚杰; 张炘; 彭志康; 刘亚洪; 汪求精; 何旭英; 黎凯锋

    2015-01-01

    Objective To discuss the application value of three-dimensional digital subtraction angiography(3D-DSA) combined with roadmap technology in diagnosis and therapy for cerebral vascular disease. Methods A total of 169 patients with cerebral vascular disease were enrolled, which included 73 males and 57 females;aged 6-81 years old with mean age of 49.31 years old. All of them were performed by DSA and endovascular treatment, and divided into 2 groups accorded to treatment process. The first group(n=104) received 3D-DSA and 2D-DSA examination which combined with roadmap treatment to identify features of aneurysm, arteriovenous malformations(AVM) and artery stenosis in image exposure of 3D-DSA, and compared results with those of 2D-DSA. The second group (n=65) was received 2D-DSA examination and interventional treatment, which also combined with roadmap treatment to compare with 3D-DSA examination combined roadmap treatment in first group. Results In aneurysmal neck detection rate, the accurate rate of 3D-DSA aneurysm was higher 16.3 %(7/43) than that of 2D-DSA, the exposure of aneurysmal neck was higher 48.2%than that of 2D-DSA. There were significant statistic differences in blood flow pattern of AVM artery and vascular malformation construction(P<0.05). The exposure of intravascular plaque by 3D-DSA was higher 30.7%than that of 2D-DSA, and accurate measurement of blood vessels stenosis of 3D-DSA was higher 42.3%than that of 2D-DSA. In treatment, there was significant statistic difference(P<0.05) in operation time and X-ray exposure time between 3D-DSA combined with roadmap technology and 2D-DSA combined with roadmap technology. And there were significant statistic differences between 3D-DSA and 2D-DSA in roadmap image times, image volume dose and X-ray radiation dosage( P<0.05). Conclusion It is demonstrated that compared with traditional 2D-DSA, the 3D-DSA combined with roadmap techniquein cerebrovascular disease has more important application value in diagnosis and

  14. Just in Time DSA the Hanford Nuclear Safety Basis Strategy

    Energy Technology Data Exchange (ETDEWEB)

    JACKSON, M.W.

    2002-06-01

    The U.S. Department of Energy, Richland Operations Office (RL) is responsible for 30 hazard category 2 and 3 nuclear facilities that are operated by its prime contractors, Fluor Hanford, Incorporated (FHI), Bechtel Hanford, Incorporated (BHI) and Pacific Northwest National Laboratory (PNNL). The publication of Title 10, Code of Federal Regulations, Part 830, Subpart B, Safely Basis Requirements (the Rule) in January 2001 requires that the Documented Safety Analyses (DSA) for these facilities be reviewed against the requirements of the Rule. Those DSAs that do not meet the requirements must either be upgraded to satisfy the Rule, or an exemption must be obtained. RL and its prime contractors have developed a Nuclear Safety Strategy that provides a comprehensive approach for supporting RL's efforts to meet its long-term objectives for hazard category 2 and 3 facilities while also meeting the requirements of the Rule. This approach will result in a reduction of the total number of safety basis documents that must be developed and maintained to support the remaining mission and closure of the Hanford Site and ensure that the documentation that must be developed will support: Compliance with the Rule; A ''Just-In-Time'' approach to development of Rule-compliant safety bases supported by temporary exemptions; and Consolidation of safety basis documents that support multiple facilities with a common mission (e.g. decontamination, decommissioning and demolition [DD&D], waste management, surveillance and maintenance). This strategy provides a clear path to transition the safety bases for the various Hanford facilities from support of operation and stabilization missions through DD&D to accelerate closure. This ''Just-In-Time'' Strategy can also be tailored for other DOE Sites, creating the potential for large cost savings and schedule reductions throughout the DOE complex.

  15. Clean Slate Environmental Remediation DSA for 10 CFR 830 Compliance

    Energy Technology Data Exchange (ETDEWEB)

    James L. Traynor, Stephen L. Nicolosi, Michael L. Space, Louis F. Restrepo

    2006-08-01

    Clean Slate Sites II and III are scheduled for environmental remediation (ER) to remove elevated levels of radionuclides in soil. These sites are contaminated with legacy remains of non-nuclear yield nuclear weapons experiments at the Nevada Test Site, that involved high explosive, fissile, and related materials. The sites may also hold unexploded ordnance (UXO) from military training activities in the area over the intervening years. Regulation 10 CFR 830 (Ref. 1) identifies DOE-STD-1120-98 (Ref. 2) and 29 CFR 1910.120 (Ref. 3) as the safe harbor methodologies for performing these remediation operations. Of these methodologies, DOE-STD-1120-98 has been superseded by DOE-STD-1120-2005 (Ref. 4). The project adopted DOE-STD-1120-2005, which includes an approach for ER projects, in combination with 29 CFR 1910.120, as the basis documents for preparing the documented safety analysis (DSA). To securely implement the safe harbor methodologies, we applied DOE-STD-1027-92 (Ref. 5) and DOE-STD-3009-94 (Ref. 6), as needed, to develop a robust hazard classification and hazards analysis that addresses non-standard hazards such as radionuclides and UXO. The hazard analyses provided the basis for identifying Technical Safety Requirements (TSR) level controls. The DOE-STD-1186-2004 (Ref. 7) methodology showed that some controls warranted elevation to Specific Administrative Control (SAC) status. In addition to the Evaluation Guideline (EG) of DOE-STD-3009-94, we also applied the DOE G 420.1 (Ref. 8) annual, radiological dose, siting criterion to define a controlled area around the operation to protect the maximally exposed offsite individual (MOI).

  16. Electrochemical degradation of reactive dyes at different DSA compositions

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Rodrigo G. da; Aquino Neto, Sydney; Andrade, Adalgisa R. de, E-mail: ardandra@ffclrp.usp.b [Universidade de Sao Paulo (FFCLRP/USP), Ribeirao Preto, SP (Brazil). Fac. de Filosofia Ciencias e Letras. Dept. de Quimica

    2011-07-01

    This paper investigates the electrochemical oxidation of the reactive dyes reactive blue 4 (RB-4) and reactive orange 16 (RO-16) on RuO{sub 2} dimensionally stable anode (DSA) electrodes. Electrolysis was achieved under galvanostatic control as a function of supporting electrolyte and electrode composition. The electrolyses, performed in either the presence or absence of NaCl, were able to promote efficient color removal; moreover, at low chloride concentration (0.01 mol L{sup -1}), total color removal was obtained after just 10 min of electrolysis, and a significant increase in total dye combustion was achieved for all the studied anodes in chloride medium (reaching ca. 80% - chemical oxygen demand - COD removal). No significant enhancement in dye color removal or mineralization was observed upon increasing chloride concentration. The influence of oxide composition on dye elimination seems to be significant in both media (with or without chloride), being Ti/Ru{sub 0.30}Ti{sub 0.70}O{sub 2}, the most active material for organic compound oxidation. The oxygen evolution reaction was shown to be a limiting reaction in both supporting electrolytes; i.e., NaCl and Na{sub 2}SO{sub 4}, and its competition with organic compound oxidation remained an obstacle. The adsorbable organo halogens formation study revealed that there is slight consumption of the undesirable species formed within the first minutes of the electrolysis, being Ti/(RuO{sub 2}){sub 0.70}(Ta{sub 2}O{sub 5}){sub 0.30} the most environmentally friendly composition. Both anode composition and chloride concentration affect the formation of these undesirable compounds. (author)

  17. Electrical study of DSA shrink process and CD rectification effect at sub-60nm using EUV test vehicle

    Science.gov (United States)

    Chi, Cheng; Liu, Chi-Chun; Meli, Luciana; Guo, Jing; Parnell, Doni; Mignot, Yann; Schmidt, Kristin; Sanchez, Martha; Farrell, Richard; Singh, Lovejeet; Furukawa, Tsuyoshi; Lai, Kafai; Xu, Yongan; Sanders, Daniel; Hetzer, David; Metz, Andrew; Burns, Sean; Felix, Nelson; Arnold, John; Corliss, Daniel

    2017-03-01

    In this study, the integrity and the benefits of the DSA shrink process were verified through a via-chain test structure, which was fabricated by either DSA or baseline litho/etch process for via layer formation while metal layer processes remain the same. The nearest distance between the vias in this test structure is below 60nm, therefore, the following process components were included: 1) lamella-forming BCP for forming self-aligned via (SAV), 2) EUV printed guiding pattern, and 3) PS-philic sidewall. The local CDU (LCDU) of minor axis was improved by 30% after DSA shrink process. We compared two DSA Via shrink processes and a DSA_Control process, in which guiding patterns (GP) were directly transferred to the bottom OPL without DSA shrink. The DSA_Control apparently resulted in larger CD, thus, showed much higher open current and shorted the dense via chains. The non-optimized DSA shrink process showed much broader current distribution than the improved DSA shrink process, which we attributed to distortion and dislocation of the vias and ineffective SAV. Furthermore, preliminary defectivity study of our latest DSA process showed that the primary defect mode is likely to be etch-related. The challenges, strategies applied to improve local CD uniformity and electrical current distribution, and potential adjustments were also discussed.

  18. Multifunctional hardmask neutral layer for directed self-assembly (DSA) patterning

    Science.gov (United States)

    Guerrero, Douglas J.; Hockey, Mary Ann; Wang, Yubao; Calderas, Eric

    2013-03-01

    Micro-phase separation for directed self-assembly (DSA) can be executed successfully only when the substrate surface on which the block co-polymer (BCP) is coated has properties that are ideal for attraction to each polymer type. The neutral underlayer (NUL) is an essential and critical component in DSA feasibility. Properties conducive for BCP patterning are primarily dependent on "brush" or "crosslinked" random co-polymer underlayers. Most DSA flows also require a lithography step (reflection control) and pattern transfer schemes at the end of the patterning process. A novel multifunctional hardmask neutral layer (HM NL) was developed to provide reflection control, surface energy matching, and pattern transfer capabilities in a grapho-epitaxy DSA process flow. It was found that the ideal surface energy for the HM NL is in the range of 38-45 dyn/cm. The robustness of the HM NL against exposure to process solvents and developers was identified. Process characteristics of the BCP (thickness, bake time and temperature) on the HM NL were defined. Using the HM NL instead of three distinct layers - bottom anti-reflective coating (BARC) and neutral and hardmask layers - in DSA line-space pitch tripling and contact hole shrinking processes was demonstrated. Finally, the capability of the HM NL to transfer a pattern into a 100-nm spin-on carbon (SOC) layer was shown.

  19. Electrochemical cell design for the impedance studies of chlorine evolution at DSA anodes

    Science.gov (United States)

    Silva, J. F.; Dias, A. C.; Araújo, P.; Brett, C. M. A.; Mendes, A.

    2016-08-01

    A new electrochemical cell design suitable for the electrochemical impedance spectroscopy (EIS) studies of chlorine evolution on Dimensionally Stable Anodes (DSA®) has been developed. Despite being considered a powerful tool, EIS has rarely been used to study the kinetics of chlorine evolution at DSA anodes. Cell designs in the open literature are unsuitable for the EIS analysis at high DSA anode current densities for chlorine evolution because they allow gas accumulation at the electrode surface. Using the new cell, the impedance spectra of the DSA anode during chlorine evolution at high sodium chloride concentration (5 mol dm-3 NaCl) and high current densities (up to 140 mA cm-2) were recorded. Additionally, polarization curves and voltammograms were obtained showing little or no noise. EIS and polarization curves evidence the role of the adsorption step in the chlorine evolution reaction, compatible with the Volmer-Heyrovsky and Volmer-Tafel mechanisms.

  20. Application of DSA and ultrasonic blood rheography (Doppler) to benign paroxysmal positional vertigo

    Energy Technology Data Exchange (ETDEWEB)

    Fujita, Nobuya; Wada, Yoshiro; Suzumura, Shigeo; Matsunaga, Takashi (Nara Medical Univ., Kashihara (Japan))

    1990-03-01

    Fourteen cases of benign paroxysmal positional vertigo (BPPV) were studied with cervical circulation using DSA and Doppler. DSA study showed 7 abnormal cases out of 10 cases of BPPV. The abnormal findings included 5 cases of stenosis and 5 cases of coiling and kinking in cervical vertebral arteries. Doppler study showed that vertebral a. and also carotid a. had low volume and high laterality of cervical blood circulation in parameter of flow and velocity. These findings suggest the cervical circulation disorder was one of background factors in pathogenesis of BPPV. (author).

  1. The protection of radioactive nuclide and nursing management in DSA room%DSA室应用放射性核素的防护与护理管理

    Institute of Scientific and Technical Information of China (English)

    张桂敏

    2009-01-01

    探讨DSA室核素的防护与护理管理.方法 回顾应用放射性核素~(125)I粒子防护上作及护理管理情况.结果 建立核素防护DSA室规范性管理,主要管理模式有人员管理、业务技能专业化管理、放射性药品及废弃物的管理、做好术前健康宣教等.结论 使患者在DSA室接受良好的核素治疗,在得到良好治疗的同时,也保护了工作环境,培养了一批专业护理人员.%Objective To discuss the protection of radioactive nuclide and nursing management in DSA room. Methods The clinical state of the protection of radioactive ~(131)I nuclide and nursing management in DSA room was retrospectively summarized. Results The standard management for the protection of radioactive nuclide in DSA room was established. The main management schemas included the management of personnel, the management of professional skills and, specialty, the management of radioactive drugs and abandoned odds and ends, preoperative health education, etc. Conclusion The standard management can ensure that the patients get a good radionuclide therapy in DSA room, and, at the same time, the working environment can be effectively protected and the professional nursing staff can be well trained.

  2. Comparative study on hepatic artery CO2-DSA and conventional-DSA in patients with liver cancer after iodine%肝癌患者经肝动脉 CO2-DSA 和常规碘-DSA诊断的对照研究

    Institute of Scientific and Technical Information of China (English)

    秦伟; 胡天刚; 赵景昊; 姜扬; 鲁云伟; 王海英; 漆素兰

    2014-01-01

    Objective To investigate the clinical efficacy and safety in patients with hepatocellular carcinoma after hepatic artery CO2-DSA and conventionaliodine-DSA ,for clinical use of CO2-DSA technology for the liver cancer patients for further diagnosis provides the reference value .Methods A total of 282 cases of hepatocellular carcinoma patients in our hospitaloncology and were divided into observation group (150 cases) and control group (132 cases) by transcatheter arterial CO2-DSA ,the control group using conventionaliodine-DSA via hepatic artery ,compared with two groups of portal vein tumor thrombus in the portal vein display ,display rate of fistula ,arteriovenous differences ,diag-nosis the image quality ,the adverse reaction rate index .Results To observe the image quality group for level 1 of the 139 cases ,98 cases were significantly higher than control group ,quality level 3 in 3 cases was less than 13 cases in the control group ,statistically significant 3 level two groups of image quality difference (P<0 .05);observation group (4 .6 ± 0 .4) portal vein was showed significantly higher scores in the control group (3 .8 ± 0 .7) ,observation group (2 .7 ± 0 .3) contour display scores were higher than those in the control group was (2 .1 ± 0 .6) ,the adverse reactions observed score was 1 .2 ± 0 .4 ,significantly lower than the control group (2 .8 ± 0 .9) ,with statistical significance of the a-bove index difference between the two groups (P<0 .05) .For observation group ,the hepatic artery and portal vein fistula ,hepatic artery hepatic vein fistula ,portal vein tumor thrombus was showed 63 (42% ) , 35 (23 .33% ) , 25 (16 .67% ) was significantly higher than that in control group 38 (28 .79% ) ,17 (12 .88% ) ,11 (8 .33% ) ,more than two sets of each index statistics difference was statistically significance (P<0 .05) .Conclusion It can improve the diagnostic image quality ,improve the accuratediagnosis rate ,reduce the adverse reaction occurred via

  3. IV-DSA of vertigo patients. Asymmetry of cervical vertebral arteries

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, Hiromi; Ito, Masatoshi; Takita, Kimio; Matsuzawa, Taiju.

    1988-04-01

    With IV-DSA(Intra-Venous Digital Subtraction Angiography), we examined the relations between vertigo or dizziness and asymmetries of cervical vertebral arteries. In this time, as the asymmetries we chose next three; hemi-stenosis, hemi-occulusion and hemi-strong tortuosity. In the appearance of the asymmetries, there was no differance between those who complain vertigo or dizziness and others.

  4. MRA Versus DSA for Follow-Up of Coiled Intracranial Aneurysms: A Meta-Analysis

    NARCIS (Netherlands)

    Amerongen, M.J. van; Boogaarts, H.D.; Vries, J. de; Verbeek, A.L.M.; Meijer, F.J.A.; Prokop, M.; Bartels, R.H.M.A.

    2014-01-01

    SUMMARY: MR angiography is proposed as a safer and less expensive alternative to the reference standard, DSA, in the follow-up of intracranial aneurysms treated with endovascular coil occlusion. We performed a systematic review and meta-analysis to evaluate the accuracy of TOF-MRA and contrast-enhan

  5. Contrast Staining on CT after DSA in Ischemic Stroke Patients Progresses to Infarction and Rarely Hemorrhages

    Science.gov (United States)

    Amans, Matthew R.; Cooke, Daniel L.; Vella, Maya; Dowd, Christopher F.; Halbach, Van V.; Higashida, Randall T.; Hetts, Steven W.

    2014-01-01

    Summary Contrast staining of brain parenchyma identified on non-contrast CT performed after DSA in patients with acute ischemic stroke (AIS) is an incompletely understood imaging finding. We hypothesize contrast staining to be an indicator of brain injury and suspect the fate of involved parenchyma to be cerebral infarction. Seventeen years of AIS data were retrospectively analyzed for contrast staining. Charts were reviewed and outcomes of the stained parenchyma were identified on subsequent CT and MRI. Thirty-six of 67 patients meeting inclusion criteria (53.7%) had contrast staining on CT obtained within 72 hours after DSA. Brain parenchyma with contrast staining in patients with AIS most often evolved into cerebral infarction (81%). Hemorrhagic transformation was less likely in cases with staining compared with hemorrhagic transformation in the cohort that did not have contrast staining of the parenchyma on post DSA CT (6% versus 25%, respectively, OR 0.17, 95% CI 0.017 – 0.98, p = 0.02). Brain parenchyma with contrast staining on CT after DSA in AIS patients was likely to infarct and unlikely to hemorrhage. PMID:24556308

  6. Detection and characterization of unruptured intracranial aneurysms: Comparison of 3T MRA and DSA.

    Science.gov (United States)

    Mine, Benjamin; Pezzullo, Martina; Roque, Gonçalo; David, Philippe; Metens, Thierry; Lubicz, Boris

    2015-06-01

    To compare magnetic resonance angiography (MRA) at 3 Tesla (3T) and digital subtraction angiography (DSA) for the detection and characterization of unruptured intracranial aneurysms (UIA). This study has been approved by our local ethical committee. From February to August 2010, 40 consecutive patients with UIA contemporarily underwent MRA at 3T including time-of-flight (TOF-MRA) and contrast enhanced (CE-MRA) techniques and DSA. MR images were independently reviewed by 3 radiologists and DSA images were reviewed by 2 radiologists together. Interobserver and intertechnique agreements were assessed for aneurysm detection and characterization including maximal diameter, neck width and the presence of a bleb or a branch arising from the sac. DS angiography revealed 56 aneurysms. Mean sensitivity and positive predictive value of MRA were 91.4% and 93.4% respectively. For UIA measurement of UIA maximal diameter (mean κ, 0.607 and 0.601 respectively) and were moderate and fair for neck width measurement respectively (mean κ, 0.456 and 0.285 respectively). For bleb detection, intertechnique and interobserver agreements were fair and slight respectively (mean κ, 0.312 and 0.116 respectively) whereas both were slight for detection of branches arising from the sac (mean κ, 0.151 and 0.070 respectively). MR angiography at 3T has a high sensitivity for the detection of UIA. However, it remains significantly inferior to DSA for morphological characterization of UIA. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  7. Skeleton-based OPC application for DSA full chip mask correction

    Science.gov (United States)

    Schneider, L.; Farys, V.; Serret, E.; Fenouillet-Beranger, C.

    2015-09-01

    Recent industrial results around directed self-assembly (DSA) of block copolymers (BCP) have demonstrated the high potential of this technique [1-2]. The main advantage being cost reduction thanks to a reduced number of lithographic steps. Meanwhile, the associated correction for mask creation must account for the introduction of this new technique, maintaining a high level of accuracy and reliability. In order to create VIA (Vertical Interconnect Layer) layer, graphoepitaxy DSA can be used. The technique relies on the creation of a confinement guides where the BCP can separate into distinct regions and resulting patterns are etched in order to obtain an ordered series of VIA contact. The printing of the guiding pattern requires the use of classical lithography. Optical proximity correction (OPC) is applied to obtain the best suited guiding pattern allowing to match a specific design target. In this study, an original approach for DSA full chip mask optical proximity correction based on a skeleton representation of a guiding pattern is proposed. The cost function for an OPC process is based on minimizing the Central Placement Error (CPE), defined as the difference between an ideal skeleton target and a generated skeleton from a guiding contour. The high performance of this approach for DSA OPC full chip correction and its ability to minimize variability error on via placement is demonstrated and reinforced by the comparison with a rigorous model. Finally this Skeleton approach is highlighted as an appropriate tool for Design rules definition.

  8. DSA-WDS Common Requirements: Developing a New Core Data Repository Certification

    Science.gov (United States)

    Minster, J. B. H.; Edmunds, R.; L'Hours, H.; Mokrane, M.; Rickards, L.

    2016-12-01

    The Data Seal of Approval (DSA) and the International Council for Science - World Data System (ICSU-WDS) have both developed minimally intensive core certification standards whereby digital repositories supply evidence that they are trustworthy and have a long-term outlook. Both DSA and WDS applicants have found core certification to be beneficial: building stakeholder confidence, enhancing the repository's reputation, and demonstrating that it is following good practices; as well as stimulating the repository to focus on processes and procedures, thereby achieving ever higher levels of professionalism over time.The DSA and WDS core certifications evolved independently serving initially different communities but both initiatives are multidisciplinary with catalogues of criteria and review procedures based on the same principles. Hence, to realize efficiencies, simplify assessment options, stimulate more certifications, and increase impact on the community, the Repository Audit and Certification DSA-WDS Partnership Working Group (WG) was established under the umbrella of the Research Data Alliance (RDA). The WG conducted a side-by-side analysis of both frameworks to unify the wording and criteria, ultimately leading to a harmonized Catalogue of Common Requirements for core certification of repositories—as well as a set of Common Procedures for their assessment.This presentation will focus on the collaborative effort by DSA and WDS to establish (1) a testbed comprising DSA and WDS certified data repositories to validate both the new Catalogue and Procedures, and (2) a joint Certification Board towards their practical implementation. We will describe:• The purpose and methodology of the testbed, including selection of repositories to be assessed against the common standard.• The results of the testbed, with an in-depth look at some of the comments received and issues highlighted.• General insights gained from evaluating the testbed results, the subsequent

  9. Toward sub-20nm pitch Fin patterning and integration with DSA

    Science.gov (United States)

    Sayan, Safak; Marzook, Taisir; Chan, BT; Vandenbroeck, Nadia; Singh, Arjun; Laidler, David; Sanchez, Efrain A.; Leray, Philippe; R. Delgadillo, Paulina; Gronheid, Roel; Vandenberghe, Geert; Clark, William; Juncker, Aurelie

    2016-03-01

    Directed Self Assembly (DSA) has gained increased momentum in recent years as a cost-effective means for extending lithography to sub-30nm pitch, primarily presenting itself as an alternative to mainstream 193i pitch division approaches such as SADP and SAQP. Towards these goals, IMEC has excelled at understanding and implementing directed self-assembly based on PS-b-PMMA block co-polymers (BCPs) using LiNe flow [1]. These efforts increase the understanding of how block copolymers might be implemented as part of HVM compatible DSA integration schemes. In recent contributions, we have proposed and successfully demonstrated two state-of-the-art CMOS process flows which employed DSA based on the PS-b-PMMA, LiNe flow at IMEC (pitch = 28 nm) to form FinFET arrays via both a `cut-last' and `cut-first' approach [2-4]. Therein, we described the relevant film stacks (hard mask and STI stacks) to achieve robust patterning and pattern transfer into IMEC's FEOL device film stacks. We also described some of the pattern placement and overlay challenges associated with these two strategies. In this contribution, we will present materials and processes for FinFET patterning and integration towards sub-20 nm pitch technology nodes. This presents a noteworthy challenge for DSA using BCPs as the ultimate resolution for PS-b-PMMA may not achieve such dimensions. The emphasis will continue to be towards patterning approaches, wafer alignment strategies, the effects of DSA processing on wafer alignment and overlay.

  10. DSA辅助超声引导下PICC导管置入的临床研究%Clinical study of DSA PICC catheter placement assisted ultrasound guidance

    Institute of Scientific and Technical Information of China (English)

    孔娟; 贾春怡; 陈艳霞

    2016-01-01

    目的:探讨数字减影血管造影机(DSA)辅助超声引导在PICC置管患者中的临床应用价值。方法在DSA室采用超声引导结合改良塞丁格技术进行穿刺成功后,在DSA的Roadmap功能下沿血管鞘注入1:1浓度的非离子型碘对比剂形成血管走行途径,在DSA监视下置入PICC导管至上腔静脉中下1/3处。结果21例患者中除一例乳癌健侧手臂无名静脉闭塞的患者改股静脉置管外,其余均顺利置管。结论将DSA及超声有效的结合起来应用于PICC导管置入技术中,既提高了穿刺成功率,又可对导管异位进行及时有效的处理,从而使PICC导管置入过程快速、安全,同时减少了相应并发症的发生,值得临床推广应用。%Objective To investigate the clinical application value of digital subtraction angiography (DSA) in patients with PICC catheter placement assisted ultrasound guidance.MethodsIn DSA room with ultrasound guidance combined with modified seldinger technique of successful puncture, 1:1 concentration of non-ionic iodine contrast agent was injected under DSA roadmap function along the vascular sheath to form the vascular route. PICC catheter was placed in superior vena cava inferior 1/3 under DSA monitoring.Results In 21 patients, except for one case of breast cancer, the patients with no other side of the arm were occluded by the femoral vein.Conclusion The combination of DSA and ultrasound is effective in the treatment of PICC catheter placement. It can improve the success rate of puncture with timely and effective treatment, so that the process of PICC catheter placement is fast and safe, and it can reduce the occurrence of complications.

  11. Neuro DSA CT颈动脉造影对诊断颈动脉狭窄的价值

    Institute of Scientific and Technical Information of China (English)

    陈小宇; 陈进军; 梁宇豪; 梁洪生; 马关华; 欧剑扬

    2016-01-01

    目的:探讨Neuro DSA CT颈动脉造影在诊断颈动脉狭窄中的价值.方法:选择41例拟诊缺血性脑梗塞患者行Neuro DSA CT颈动脉造影及数字减影血管造影(DSA).Neuro DSA CT颈动脉造影应用三维处理后,测量颅内外血管狭窄程度,并与DSA比较.结果:Neuro DSA CT与DSA对颈内动脉狭窄程度分级判断的一致性为79.2%(Kappa =0.71,P< 0.01),Neuro DSA CT颈动脉造影对颈内动脉各级狭窄诊断的灵敏度,特异度均较高.结论:Neuro DSA CT颈动脉造影可以清晰显示颈动脉狭窄程度,有较高的准确性,可以作为颈动脉狭窄性病变的筛选方法.

  12. Transvenous digital subtraction angiography (DSA) of the thoracic aorta after surgical correction of aortic coarctation

    Energy Technology Data Exchange (ETDEWEB)

    Arlart, I.P.; Hamann, H.; Stenz, R.

    1985-01-01

    25 patients (normotensive n = 19, hypertensive n = 6) underwent DSA control following corrective surgery of a coarcatation of the thoracic aorta to exclude vascular complications. Simultaneously pressure gradients were determined between upper and lower extremities using the doppler-sonography. DSA was diagnostic in all patients. 2 cases showed a patch-dependent dilatation, in 1 case an anastomotic aneurysm could be demonstrated. In 6 patients with hypoplastic aortic arch and 2 patients with a slight reduction of the diameter in the anastomotic region a pathological pressure-gradient was measured. In these patients the ratio of aortic arch rsp. anastomosis/descending aorta was reduced in diameter (< 0,66) and area (< 44). Hypertension could not be related to pressure gradients or vascular disorders.

  13. Minimally Invasive Monitoring of Chronic Central Venous Catheter Patency in Mice Using Digital Subtraction Angiography (DSA.

    Directory of Open Access Journals (Sweden)

    Giovanna Figueiredo

    Full Text Available Repetitive administration of medication or contrast agents is frequently performed in mice. The introduction of vascular access mini-ports (VAMP for mice allows long-term vascular catheterization, hereby eliminating the need for repeated vessel puncture. With catheter occlusion being the most commonly reported complication of chronic jugular vein catheterization, we tested whether digital subtraction angiography (DSA can be utilized to evaluate VAMP patency in mice.Twenty-three mice underwent catheterization of the jugular vein and subcutaneous implantation of a VAMP. The VAMP was flushed every second day with 50 μL of heparinized saline solution (25 IU/ml. DSA was performed during injection of 100 μL of an iodine based contrast agent using an industrial X-ray inspection system intraoperatively, as well as 7±2 and 14±2 days post implantation.DSA allowed localization of catheter tip position, to rule out dislocation, kinking or occlusion of a microcatheter, and to evaluate parent vessel patency. In addition, we observed different ante- and retrograde collateral flow patterns in case of jugular vein occlusion. More exactly, 30% of animals showed parent vessel occlusion after 7±2 days in our setting. At this time point, nevertheless, all VAMPs verified intravascular contrast administration. After 14±2 days, intravascular contrast injection was verified in 70% of the implanted VAMPs, whereas at this point of time 5 animals had died or were sacrificed and in 2 mice parent vessel occlusion hampered intravascular contrast injection. Notably, no occlusion of the catheter itself was observed.From our observations we conclude DSA to be a fast and valuable minimally invasive tool for investigation of catheter and parent vessel patency and for anatomical studies of collateral blood flow in animals as small as mice.

  14. Non-contrast-enhanced MRA of renal artery stenosis: validation against DSA in a porcine model

    Energy Technology Data Exchange (ETDEWEB)

    Bley, T.A. [University of Wuerzburg, Department of Diagnostic and Interventional Radiology, Wuerzburg (Germany); University of Wisconsin, Department of Radiology, Madison, WI (United States); Francois, C.J.; Schiebler, M.L. [University of Wisconsin, Department of Radiology, Madison, WI (United States); Wieben, O.; Del Rio, A.M.; Grist, T.M. [University of Wisconsin, Department of Radiology, Madison, WI (United States); University of Wisconsin, Department of Medical Physics, Madison, WI (United States); Takei, N. [GE Healthcare, MR Applied Sciences Laboratory, Tokyo (Japan); Brittain, J.H. [University of Wisconsin, Department of Radiology, Madison, WI (United States); GE Healthcare, MR Applied Sciences Laboratory, Madison, WI (United States); Reeder, S.B. [University of Wisconsin, Department of Radiology, Madison, WI (United States); University of Wisconsin, Department of Medical Physics, Madison, WI (United States); University of Wisconsin, Department of Biomedical Engineering, Madison, WI (United States); University of Wisconsin, Department of Medicine, Madison, WI (United States); University of Wisconsin, Department of Emergency Medicine, Madison, WI (United States)

    2016-02-15

    To compare 3D-inversion-recovery balanced steady-state free precession (IR-bSSFP) non-contrast-enhanced magnetic resonance angiography (MRA) with 3D-contrast-enhanced MRA (CE-MRA) for assessment of renal artery stenosis (RAS) using digital subtraction angiography (DSA) as the reference standard. Bilateral RAS were surgically created in 12 swine. IR-bSSFP and CE-MRA were acquired at 1.5 T and compared to rotational DSA. Three experienced cardiovascular radiologists evaluated the IR-bSSFP and CE-MRA studies independently. Linear regression models were used to calibrate and assess the accuracy of IR-bSSFP and CE-MRA, separately, against DSA. The coefficient of determination and Cohen's kappa coefficient were also generated. Calibration of the three readers' RAS grading revealed R{sup 2} values of 0.52, 0.37 and 0.59 for NCE-MRA and 0.48, 0.53 and 0.71 for CE-MRA. Inter-rater agreement demonstrated Cohen's kappa values ranging from 0.25 to 0.65. Distal renal artery branch vessels were visible to a significantly higher degree with NCE-MRA compared to CE-MRA (p < 0.001). Image quality was rated excellent for both sequences, although image noise was higher with CE-MRA (p < 0.05). In no cases did noise interfere with image interpretation. In a well-controlled animal model of surgically induced RAS, IR-bSSFP based NCE-MRA and CE-MRA accurately graded RAS with a tendency for stenosis overestimation, compared to DSA. (orig.)

  15. DSA三维导航技术在颅内动脉瘤介入治疗中的应用%Application of DSA three-dimensional navigation technology in the interventional treatment of intracranial aneurysms

    Institute of Scientific and Technical Information of China (English)

    吴奇华; 曾勇明

    2012-01-01

    目的 探讨数字减影血管造影(DSA)三维导航技术在颅内动脉瘤介入治疗中的价值.方法 应用三维导航技术,评价86例颅内动脉瘤介入治疗患者DSA三维导航技术的应用效果.结果 86例颅内动脉瘤患者均行旋转DSA,在三维导航技术引导下,84例完成颅内动脉瘤的栓塞治疗;2例定位失败,未完成治疗,成功率为97.67%.结论 三维导航技术能提高颅内动脉瘤介入治疗成功率,缩短治疗时间,降低辐射剂量,是一种有效的介入治疗辅助技术.%Objective To explore the value of digital subtraction angiography(DSA) three-dimensional navigation technology in the interventional treatment of intracranial aneurysms. Methods Three-dimensional navigation technology was applied to 86 patients with intracranial aneurysms who accepted interventional treatment,and application effect of DSA three-dimensional navigation technology was evaluated. Results All 86 patients with intracranial aneurysms were subjected to rotational DSA. Under the guidance of three-dimensional navigation technology, 84 of them complete the embolization of intracranial aneurysms, and 2 of them failed to location and did not complete the treatment, with the success rate of 97. 6%. Conclusion Three-dimensional navigation technology is an effective assistive technology of intervention treatment, which can improve the success rate of intracranial aneurysms treatment,shorten the treatment duration,decrease the radiation dose.

  16. Application of DSA and CT perfusion imaging for cerebral rerascularization in treatment of unilateral moyamoya disease%DSA 及 CT 灌注成像在单侧烟雾病脑血管重建术中的应用

    Institute of Scientific and Technical Information of China (English)

    张亚男; 薛静; 高培毅

    2014-01-01

    Objectire:To explore the clinical value of DSA and CT perfusion imaging (CTPI)for cerebral revascula-rization of unilateral moyamoya disease.Methods:The clinical and imaging data of 51 patients with unilateral moyamoya di-sease undergone cerebral revascularization were analyzed restrospectively.Of 51 cases,49 and 13 cases with superficial tem-poral artery to middle cerebral artery (STA-MCA)bypass underwent pre-and post-surgery DSA respectively,all cases un-derwent CTPI before operation,33 and 13 cases underwent short-or long-term postoperative CTPI respectively.According to the DSA data,degree of cerebrovascular stenosis,classification of collateral vessel and stage of internal carotid artery (ICA)disease were analyzed.On the CTPI parameter maps (including CBF,CBV,MTT and TTP)quantitative measure-ment of five ROIs was performed,and pre-infarction stage and perfusion state after operation were evaluated.Paired t test or signed rank sum test was used for statistic analysis.Results:①Preoperative DSA showed that MCA was involved in all ca-ses,71.4% (35/49 )of which were single MCA involvement;ICA stages of 40.8% (20/49 )patients were in stage Ⅳ;moyamoya vessels at the base of the brain were existed in 49 cases,and collateral vessels originated from PCA were existed in 31 cases.In the postoperative evaluation,21 cases underwent cerebrovascular examinations after STA-MCA bypass and the patency rate of bypasses was 95.2% (20/21 );Of 21 cases,13 cases underwent DSA before and after STA-MCA by-pass,and 9 cases showed that net-like vessels at the base of brain decreased or disappeared after operation (69.2%).②pre-operative CTPI of 51 cases showed that the ipsilateral value of CBV,MTT and TTP in the MCA territory,basal ganglia and PCA territory and MTT in the ACA territory all increased,CBF in the MCA territory decreased,with statistic difference all when compared with those of the contralateral side (P <0.05 ).In addition,a qualitative evaluation showed that 66

  17. Evaluation of DSA effects on SA516-Gr. 70 steel for reactor coolant piping elbow material. (Dynamic and quasi-static J-R curve characteristics.)

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Bong Sang; Hong, Jun Hwa; Yoon, Ji Hyun; Oh, Jong Myung; Kim, Jin Won [Korea Atomic Energy Reserach Institute, Taejon (Korea, Republic of)

    1997-11-01

    Dynamic and quasi-static J-R curve tests for RCS piping elbow material (SA516-Gr.70) were performed by DCPD method at various temperatures (25 deg C - 316 deg C). The objective of this project was to qualify that DSA would not affect the design safety margin for LBB analysis in the normal operating temperature region. This report describes the effects of temperature and loading rate on J-R characteristics of SA516-Gr. 70 steel for reactor coolant piping elbow material. 13 refs., 3 tabs., 9 figs. (author)

  18. Clinical application of venography with DSA in lower extremity%DSA在下肢深静脉造影中的临床应用

    Institute of Scientific and Technical Information of China (English)

    胡可明; 孙志先; 张毅; 汪志超; 陈康海; 汪长胜

    2012-01-01

    Objective To explore the clinical value of venography with DSA in lower extremity. Methods 28 patients(33 limbs) with lower extremity venous disease were examined by anterograde or retrograde venography with DSA. 3 patients of them received catheterization venography by percutaneous popliteal vein. Results The various venous diseases of lower extremity were classified according to the main X-ray appearances as follows: there were only superficial venous valve insufficiency in 5 limbs(15%) , communicating venous valve insufficiency in 22 limbs (67 %) , primary deep venous valve insufficiency in 17 limbs (52%) , deep venous thrombosis in 8 limbs(24%) and sequelae of deep venous thrombosis in 3 limbs (9%). According to severity of the reflux , there were grade Ⅰ in 5 vessels, grade Ⅱ in 7 vessels, grade Ⅲ in 3 vessels, grade Ⅳ in 1 vessel. Conclusion The venography with DSA in lower extremity can display the location,shape and extent of venous lesions, and provide reliable evidence in the selection of therapeutic methods. It is worth popularizing clinically.%目的 探讨DSA 在下肢深静脉造影中的临床应用.方法 28例(33条)下肢静脉疾病的患者在DSA下行下肢深静脉顺、逆行造影,其中3例行经皮穿刺腘静脉插管造影.结果 根据主要X线表现将下肢静脉疾病分为:单纯性浅静脉瓣膜功能不全5条(15%),交通静脉瓣膜功能不全22条(67%),原发性深静脉瓣膜功能不全17条(52%),深静脉血栓形成8条(24%)和深静脉血栓形成后遗症3条(9%).根据深静脉逆流程度分为:Ⅰ级5条,Ⅱ级7条,Ⅲ级3条,Ⅳ级1条.结论 在DSA下行下肢深静脉造影能清楚地显示病变的部位、形态和范围,为临床治疗方案的选择提供可靠依据,值得推广.

  19. Investigation of Clinical Application Using Fusion Imaging Combined CTA with DSA-DYNA-CT in the Endovascular Prosthesis for Abdominal Aortic Aneurysm%CTA与DSA-DYNA-CT融合图像在腹主动脉瘤腔内修复术中的应用

    Institute of Scientific and Technical Information of China (English)

    侯凯; 饶圣祥; 顾君英; 曾蒙苏

    2012-01-01

    目的:评价利用CTA与DSA-DYNA-CT的融合图像作为腹主动脉瘤腔内修复术中的三维血管路径图的可行性.方法:腹主动脉瘤腔内修复术患者15例,术前行胸腹主动脉CTA检查,术中在腹主动脉瘤部位行数字平板DSA结合旋转断层重组技术所获得的CT样图像(DSA-DYNA-CT)的数据采集,在工作站中利用“syngo inspace 3D-fusion”功能进行两者图像融合,作为实时透视过程中的三维血管路径图.结果:CTA与DSA-DYNA-CT在融合过程中,10例骨性错位<2 mm,余5例手动调节后均骨性对位满意;肾动脉融合图像与实时透视的图像的位移较大,其中46.7%(7/15)的患者上下位移>2 mm),66.7%(10/15)的患者左右位移>2 mm.结论:将CTA与DSA-DYNA CT的融合图像作为大血管的DSA三维血管路径图,在不用造影剂的情况下,可以在术中多角度观察导丝及支架与周围血管的位置关系.%Objective:To evaluate the DSA 3D-roadmap in the endovascular prosthesis for abdominal aortic aneurysm with the fusion image of CT angiography(CTA) and DSA-DYNA-CT. Methods: Fifteen patients with abdominal aortic aneurysm were enrolled in the study. Aortic CTA and DSA-DYNA-CT imaging were performed to the fusion imaging in the workstation with the software of syngo inspace 3D fusion for the abdominal aortic aneurysm without contrast medium administration. Then the fusion image was used as the 3D-roadmap in the process of real-time fluoroscopy. Results: In the fusion process of CTA and DYNA-CT, osseous paraposition were 2 mm in 5 cases, but the osseous registration can be satisfied with the manual adjustment ?2mm). Due to the influence of the stent delivery devices, the abdominal aorta has marked displacement. Displacement was more than 2 mm between up and down in 7 cases (7/15,46. 7%), and displacement was greater than 2 mm between left and right in 10 patients (10/15,66. 7%). Conclusions: Without contrast medium administration,the 3D-roadmap, can be

  20. Application of stepping DSA technique in lower limb venography anterograde%步进式DSA技术在下肢顺行性静脉造影中的应用

    Institute of Scientific and Technical Information of China (English)

    陈燕; 黄健

    2011-01-01

    目的 评价步进式DSA技术在下肢顺行性静脉造影中的应用价值.方法 将要求行下肢静脉造影患者40例随机分为2组:研究组20例行步进式DSA造影,对照组20例行传统分段式DSA造影.由介入科主治以上医生及技师共同将图像满意率、造影耗时、吸收辐射剂量(DAP)、造影剂用量等进行比较评价.结果 步进式DSA造影与传统分段式DSA造影相比较,2种方法造影图像质量相仿,但步进式DSA造影对观察由下而上血流的连续性,血流动态流向,判断静脉的解剖形态及病理血管血流状况,图像更加富有整体性,一次性成功率85%(17/20).其次吸收辐射剂量,造影剂用量,总体检查时间均明显减少.结论 对下肢静脉病变,步进式DSA造影较传统分段式DSA造影环节更为简化,图像整体观及实用性强,对下肢静脉病变介入治疗方案的决策以及外科手术有很重要的客观指引作用.%Objective To investigate the value of the application of step - DSA in lower extremity venography anterograde. Methods Forty patients of lower limb venography were randomly divided into two groups: the research group of 20 cases using step - DSA and the compared group of 20 using the traditional sub - type DSA. Then the attending doctors and technicians in Invasive Technology Department had a comparison and assessment in the aspects of the image satisfaction rate, DSA time -consuming, dose area product(DAP) , dosage of contrast agent and so on. Results The DSA image quality of the two methods was similar, but compared with the traditional sub - type DSA, the stepping DSA has a better image and success rate of 85% (17/20) at the first treatment through observing the continuity of bottom - up bloodstream, dynamic flow of blood and determining the venous anatomical form and pathological blood flow conditions. Furthermore, with stepping DSA, the absorbed radiation dose, dosage of contrast agent and the total inspection time have

  1. Sensitivity evaluation of DSA-based parametric imaging using Doppler ultrasound in neurovascular phantoms

    Science.gov (United States)

    Balasubramoniam, A.; Bednarek, D. R.; Rudin, S.; Ionita, C. N.

    2016-03-01

    An evaluation of the relation between parametric imaging results obtained from Digital Subtraction Angiography (DSA) images and blood-flow velocity measured using Doppler ultrasound in patient-specific neurovascular phantoms is provided. A silicone neurovascular phantom containing internal carotid artery, middle cerebral artery and anterior communicating artery was embedded in a tissue equivalent gel. The gel prevented movement of the vessels when blood mimicking fluid was pumped through it to obtain Colour Doppler images. The phantom was connected to a peristaltic pump, simulating physiological flow conditions. To obtain the parametric images, water was pumped through the phantom at various flow rates (100, 120 and 160 ml/min) and 10 ml contrast boluses were injected. DSA images were obtained at 10 frames/sec from the Toshiba C-arm and DSA image sequences were input into LabVIEW software to get parametric maps from time-density curves. The parametric maps were compared with velocities determined by Doppler ultrasound at the internal carotid artery. The velocities measured by the Doppler ultrasound were 38, 48 and 65 cm/s for flow rates of 100, 120 and 160 ml/min, respectively. For the 20% increase in flow rate, the percentage change of blood velocity measured by Doppler ultrasound was 26.3%. Correspondingly, there was a 20% decrease of Bolus Arrival Time (BAT) and 14.3% decrease of Mean Transit Time (MTT), showing strong inverse correlation with Doppler measured velocity. The parametric imaging parameters are quite sensitive to velocity changes and are well correlated to the velocities measured by Doppler ultrasound.

  2. A Tabu Search DSA Algorithm for Reward Maximization in Cellular Networks

    OpenAIRE

    Kamal, Hany; Coupechoux, Marceau; Godlewski, Philippe

    2010-01-01

    International audience; In this paper, we present and analyze a Tabu Search (TS) algorithm for DSA (Dynamic Spectrum Access) in cellular networks. We study a mono-operator case where the operator is providing packet services to the end-users. The objective of the cellular operator is to maximize its reward while taking into account the trade-off between the spectrum cost and the revenues obtained from end-users. These revenue are modeled here as an increasing function of the achieved throughp...

  3. Gadofosveset-enhanced MR angiography of the pedal arteries in patients with diabetes mellitus and comparison with selective intraarterial DSA

    Energy Technology Data Exchange (ETDEWEB)

    Roehrl, Boris; Kunz, Rainer Peter; Oberholzer, Katja; Pitton, Michael Bernhard; Dueber, Christoph; Kreitner, Karl-Friedrich [Johannes Gutenberg University Mainz, Department of Diagnostic and Interventional Radiology, Mainz (Germany); Neufang, Achim [Johannes Gutenberg University Mainz, Department of Cardiothoracic and Vascular Surgery, Mainz (Germany)

    2009-12-15

    To compare gadofosveset-enhanced magnetic resonance angiography (MRA) of the pedal vasculature with selective intraarterial DSA. Eighteen patients with PAOD and type II diabetes were prospectively examined at 1.5 T. For contrast enhancement, 0.03 mmol/kg body weight gadofosveset was used. MR imaging consisted of dynamic and of high-resolution steady-state imaging. Selective digital subtraction angiography (DSA) was performed within 5 days and served as standard of reference. Image analysis was done by two observers. There were no differences between MRA and DSA regarding overall image quality. First-pass MRA detected significantly more patent vessel segments than did DSA (P < 0.001, kappa = 0.46). Interobserver agreement of MRA was very good with respect to the detection of patent vessel segments and the assessment of hemodynamically relevant stenoses (kappa = 0.97 and 0.89, respectively). Steady-state imaging depicted significantly more patent metatarsal arteries than did dynamic imaging, and delineated inflammatory complications including osteomyelitis, soft-tissue abscesses, and fistulas related to the diabetic foot. Gadofosveset-enhanced MRA of the pedal vasculature proved to be superior to DSA. It offered a long imaging time window, and allowed for better depiction of the pedal outflow. Steady-state imaging delineated inflammatory complications associated with the diabetic foot. (orig.)

  4. Flow modification in canine intracranial aneurysm model by an asymmetric stent: studies using digital subtraction angiography (DSA) and image-based computational fluid dynamics (CFD) analyses

    Science.gov (United States)

    Hoi, Yiemeng; Ionita, Ciprian N.; Tranquebar, Rekha V.; Hoffmann, Kenneth R.; Woodward, Scott H.; Taulbee, Dale B.; Meng, Hui; Rudin, Stephen

    2006-03-01

    An asymmetric stent with low porosity patch across the intracranial aneurysm neck and high porosity elsewhere is designed to modify the flow to result in thrombogenesis and occlusion of the aneurysm and yet to reduce the possibility of also occluding adjacent perforator vessels. The purposes of this study are to evaluate the flow field induced by an asymmetric stent using both numerical and digital subtraction angiography (DSA) methods and to quantify the flow dynamics of an asymmetric stent in an in vivo aneurysm model. We created a vein-pouch aneurysm model on the canine carotid artery. An asymmetric stent was implanted at the aneurysm, with 25% porosity across the aneurysm neck and 80% porosity elsewhere. The aneurysm geometry, before and after stent implantation, was acquired using cone beam CT and reconstructed for computational fluid dynamics (CFD) analysis. Both steady-state and pulsatile flow conditions using the measured waveforms from the aneurysm model were studied. To reduce computational costs, we modeled the asymmetric stent effect by specifying a pressure drop over the layer across the aneurysm orifice where the low porosity patch was located. From the CFD results, we found the asymmetric stent reduced the inflow into the aneurysm by 51%, and appeared to create a stasis-like environment which favors thrombus formation. The DSA sequences also showed substantial flow reduction into the aneurysm. Asymmetric stents may be a viable image guided intervention for treating intracranial aneurysms with desired flow modification features.

  5. L’ICF-CY per la progettazione inclusiva per gli alunni con DSA

    Directory of Open Access Journals (Sweden)

    Marina Chiaro

    2013-09-01

    Full Text Available Il lavoro presenta i principali risultati di una ricerca a carattere teorico-esplorativo, finalizzata a valutare quanto lo strumento dell’International Classification of Functioning, Disability and Health for Children and Youth (ICF-CY sia conosciuto ed utilizzato nei diversi contesti educativi per l’osservazione degli allievi e del loro “funzionamento” in senso dinamico-evolutivo, in interazione con i fattori ambientali, e finalizzato ad una progettazione educativo-didattica significativamente orientata alla prospettiva inclusiva. A tal fine sono stati intervistati gli insegnanti delle scuole di ogni ordine e grado del Lazio iscritti al Master in Didattica e Psicopedagogia per gli alunni con Disturbi Specifici di Apprendimento (DSA presso l’Università degli Studi di Roma Tre. La scelta è coerente con la direttiva MIUR del 2012 dove viene considerato rilevante ai fini della individuazione dei Bisogni Educativi Speciali dell’alunno, ed in particolare degli allievi con DSA, l’apporto, anche sul piano culturale del modello diagnostico ICF-CY che considera la persona nella sua totalità, in una prospettiva bio-psico-sociale.

  6. Production and contribution of hydroxyl radicals between the DSA anode and water interface

    Institute of Scientific and Technical Information of China (English)

    Guoting Li; Meiya Zhu; Jing Chen; Yunxia Li; Xiwang Zhang

    2011-01-01

    Hydroxyl radicals play the key role during electrochemical oxidation and photoelectrochemical oxidation. The production and effect of hydroxyl radicals on the interface between DSA anode and water was investigated by examining the quenching effect of iso-propanol on Orange Ⅱ decolorization. We observed that with an increase in electrode potential from 4 to 12 V across electrodes at pH 7.0, the contribution percentage of hydroxyl radicals increased dramatically. More OH radicals were produced in acidic and alkaline conditions than at neutral conditions. At electrode potential of 4 V, the contribution percentage of hydroxyl radicals was obviously higher at near neutral pH conditions, while removal efficiency of Orange Ⅱ achieved was the lowest concurrently. Finally, for photocatalytic oxidation,electrochemical oxidation, and photoelcctrochemical oxidation using the same DSA electrode, the effect of hydroxyl radicals proved to be dominant in photocatalytic oxidation but the contribution of hydroxyl radicals was not dominant in electrochemical oxidation,which implies the necessity of UV irradiation for electrochemical oxidation during water treatrnent.

  7. Challenges in LER/CDU metrology in DSA: placement error and cross-line correlations

    Science.gov (United States)

    Constantoudis, Vassilios; Kuppuswamy, Vijaya-Kumar M.; Gogolides, Evangelos; Pret, Alessandro V.; Pathangi, Hari; Gronheid, Roel

    2016-03-01

    DSA lithography poses new challenges in LER/LWR metrology due to its self-organized and pitch-based nature. To cope with these challenges, a novel characterization approach with new metrics and updating the older ones is required. To this end, we focus on two specific challenges of DSA line patterns: a) the large correlations between the left and right edges of a line (line wiggling, rms(LWR)

  8. WDS/DSA Certification - International collaboration for a trustworthy research data infrastructure

    Science.gov (United States)

    Mokrane, Mustapha; Hugo, Wim; Harrison, Sandy

    2016-04-01

    , German Institute for Standardization (DIN) standard 31644, Trustworthy Repositories Audit and Certification (TRAC) criteria and the International Organization for Standardization (ISO) standard 16363. In addition, the Data Seal of Approval (DSA) and WDS have set up core certification mechanisms for trusted digital repositories in 2009, which are increasingly recognized as de facto standards. While DSA emerged in Europe in the Humanities and Social Sciences, WDS started as an international initiative with historical roots in the Earth and Space Sciences. Their catalogues of requirements and review procedures are based on the same principles of openness, transparency. A unique feature of the DSA and WDS certification is that it strikes a balance between simplicity, robustness and the effort required to complete. A successful international cross-project collaboration was initiated between WDS and DSA under the umbrella of the Research Data Alliance (RDA), an international initiative started in 2013 to promote data interoperability which provided a useful and neutral forum. A joint working group was established in early 2014 to reconcile and simplify the array of certification options and improve and stimulate core certification for scientific data services. The outputs of this collaboration are a Catalogue of Common Requirements (https://goo.gl/LJZqDo) and a Catalogue of Common Procedures (https://goo.gl/vNR0q1) which will be implemented jointly by WDS and DSA.

  9. Mask free intravenous 3D digital subtraction angiography (IV 3D-DSA) from a single C-arm acquisition

    Science.gov (United States)

    Li, Yinsheng; Niu, Kai; Yang, Pengfei; Aagaard-Kienitz, Beveley; Niemann, David B.; Ahmed, Azam S.; Strother, Charles; Chen, Guang-Hong

    2016-03-01

    Currently, clinical acquisition of IV 3D-DSA requires two separate scans: one mask scan without contrast medium and a filled scan with contrast injection. Having two separate scans adds radiation dose to the patient and increases the likelihood of suffering inadvertent patient motion induced mis-registration and the associated mis-registraion artifacts in IV 3D-DSA images. In this paper, a new technique, SMART-RECON is introduced to generate IV 3D-DSA images from a single Cone Beam CT (CBCT) acquisition to eliminate the mask scan. Potential benefits of eliminating mask scan would be: (1) both radiation dose and scan time can be reduced by a factor of 2; (2) intra-sweep motion can be eliminated; (3) inter-sweep motion can be mitigated. Numerical simulations were used to validate the algorithm in terms of contrast recoverability and the ability to mitigate limited view artifacts.

  10. The value of three-dimensional DSA in diagnosis and interventional treatment of Budd-Chiari syndrome caused by the obstruction of the inferior vena cava%三维DSA在腔静脉闭塞型布加综合征诊断和介入治疗中的价值

    Institute of Scientific and Technical Information of China (English)

    张庆桥; 陈雪荣; 闵继忠; 祖茂衡; 徐浩; 顾玉明; 李国均; 魏宁; 许伟; 刘洪涛; 崔艳峰

    2008-01-01

    目的 评价三维DSA(3D DSA)在腔静脉闭塞型布加综合征诊断和介入治疗中的价值.方法21例下腔静脉(IVC)闭塞情况复杂的布加综合征患者经二维DSA(2D DSA)后前位检查确诊后,加做3D DSA检查.由2名介入放射专业主任医师采用双盲法分别阅读2D DSA和3D DSA图像以评价IVC解剖结构,并采用x2检验比较两者对血管的显示情况.根据2D和3D DSA检查结果施行IVC球囊扩张术或支架置入术.结果 所有患者3D DSA均能准确显示IVC闭塞端位置、形态、侧支血管开口及其空间位置关系,检出侧支血管起源于闭塞端9例;2D DSA能显示闭塞端位置、形态、侧支血管开口及其空间关系7例,检出侧支血管起源于闭塞端2例,两者比较差异均有统计学意义(x2值分别为12.07和5.14,P<0.05).仿真血管内镜成像显示IVC内游离血栓3例、附壁血栓1例.全部患者均治疗成功,1例并发IVC破裂出血,无其他并发症.结论3D DSA在IVC闭塞的诊断中能提供有价值信息,对腔静脉闭塞型布加综合征介入治疗有指导意义.%Objective To investigate the value of three-dimensional digital subtraction angiography (3D-DSA)in the diagnosis and interventional treatment of Budd-Chiari syndrome caused by the obstruction of inferior vena cava(IVC).Methods Twenty-one patients with complex Budd-Chiari syndrome caused by the obstruction of IVC underwent 3D-DSA after two-dimensional-DSA(2D-DSA)was performed with posterior-anterior view.The images of 2D-DSA and 3D-DSA were independently reviewed by two senior interventional radiologists iu a double-blinded way.Percutaneous transluminal angioplasty or stent placement of IVC were performed according to the results of 2D-DSA and 3D-DSA.Results Different aspects of the IVC in all patients were demonstrated on the 3D-DSA images,including the mowhology and the location of obstructions,the origins of collateral vessels and their relationships to the IVC.Collateral vessels

  11. Superior diagnostic strength of combined contrast enhanced MR-angiography and MR-imaging compared to intra-arterial DSA in liver transplantation candidates

    NARCIS (Netherlands)

    Boeve, WJ; Kok, T; Haagsma, EB; Slooff, MJH; Sluiter, WJ; Kamman, RL

    2001-01-01

    To evaluate the diagnostic value of combined contrast enhanced MRA (ce-MRA) and MRI compared to that of intra-arterial DSA (i.a.DSA) in liver transplantation, transjugular porto-systemic (TIPSS) and spleno-renal shunt candidates. 50 patients in the workup for liver transplantation underwent ce-MRA/M

  12. Theoretical investigation of electronic structure and charge transport property of 9,10-distyrylanthracene (DSA) derivatives with high solid-state luminescent efficiency.

    Science.gov (United States)

    Wang, Lijuan; Xu, Bin; Zhang, Jibo; Dong, Yujie; Wen, Shanpeng; Zhang, Houyu; Tian, Wenjing

    2013-02-21

    The electronic structure and charge transport property of 9,10-distyrylanthracene (DSA) and its derivatives with high solid-state luminescent efficiency were investigated by using density functional theory (DFT). The impact of substituents on the optimized structure, reorganization energy, ionization potential (IP) and electronic affinity (EA), frontier orbitals, crystal packing, transfer integrals and charge mobility were explored based on Marcus theory. It was found that the hole mobility of DSA was 0.21 cm(2) V(-1) s(-1) while the electron mobility was 0.026 cm(2) V(-1) s(-1), which were relatively high due to the low reorganization energies and high transfer integrals. The calculated results showed that the charge transport property of these compounds can be significantly tuned via introducing different substituents to DSA. When one electron-withdrawing group (cyano group) was introduced into DSA, DSA-CN exhibited hole mobility of 0.14 cm(2) V(-1) s(-1) which was on the same order of that of DSA. However, the electron mobility of DSA-CN decreased to 8.14 × 10(-4) cm(2) V(-1) s(-1) due to the relatively large reorganization energy and disadvantageous transfer integral. The effect of electron-donating substituents was investigated by introducing methoxy group and tertiary butyl into DSA. DSA-OCH(3) and DSA-TBU showed much lower charge mobility than DSA resulting from the steric hindrance of substituents. On the other hand, both of them exhibited balanced transport properties (for DSA-OCH(3), the hole and electron mobility was 0.0026 and 0.0027 cm(2) V(-1) s(-1); for DSA-TBU, the hole and electron mobility was 0.045 and 0.012 cm(2) V(-1) s(-1)) because of their similar transfer integrals for both hole and electron. DSA and its derivatives were supposed to be one of the most excellent emissive materials for organic electroluminescent applications because of their high charge mobility and high solid-state luminescent efficiency.

  13. Just in Time DSA-The Hanford Nuclear Safety Basis Strategy

    Energy Technology Data Exchange (ETDEWEB)

    Olinger, S. J.; Buhl, A. R.

    2002-02-26

    The U.S. Department of Energy, Richland Operations Office (RL) is responsible for 30 hazard category 2 and 3 nuclear facilities that are operated by its prime contractors, Fluor Hanford Incorporated (FHI), Bechtel Hanford, Incorporated (BHI) and Pacific Northwest National Laboratory (PNNL). The publication of Title 10, Code of Federal Regulations, Part 830, Subpart B, Safety Basis Requirements (the Rule) in January 2001 imposed the requirement that the Documented Safety Analyses (DSA) for these facilities be reviewed against the requirements of the Rule. Those DSA that do not meet the requirements must either be upgraded to satisfy the Rule, or an exemption must be obtained. RL and its prime contractors have developed a Nuclear Safety Strategy that provides a comprehensive approach for supporting RL's efforts to meet its long term objectives for hazard category 2 and 3 facilities while also meeting the requirements of the Rule. This approach will result in a reduction of the total number of safety basis documents that must be developed and maintained to support the remaining mission and closure of the Hanford Site and ensure that the documentation that must be developed will support: compliance with the Rule; a ''Just-In-Time'' approach to development of Rule-compliant safety bases supported by temporary exemptions; and consolidation of safety basis documents that support multiple facilities with a common mission (e.g. decontamination, decommissioning and demolition [DD&D], waste management, surveillance and maintenance). This strategy provides a clear path to transition the safety bases for the various Hanford facilities from support of operation and stabilization missions through DD&D to accelerate closure. This ''Just-In-Time'' Strategy can also be tailored for other DOE Sites, creating the potential for large cost savings and schedule reductions throughout the DOE complex.

  14. The clinical value of the special functions of DSA in interventional embolization for uterine fibroids%DSA特殊功能在子宫肌瘤栓塞治疗中的价值

    Institute of Scientific and Technical Information of China (English)

    何玉圣; 鲁东; 吕维富; 张劲松

    2009-01-01

    目的 评价DSA特殊功能在子宫肌瘤栓塞治疗中的价值.方法 46例子宫肌瘤栓塞中26例应用DSA特殊功能:3D-DSA、最佳工作体位、路图技术,20例采用常规DSA造影,对两种方法的对比剂用量、介入手术时间和透视时间进行比较和分析.结果 术中应用DSA特殊功能与常规DSA组比较,对比剂用量和透视时间明显减少(P0.05).结论 DSA特殊功能在子宫肌瘤栓塞中的应用能缩短手术时间,降低手术风险.可视化三维重建技术对介入手术操作具有重要指导意义.%Objective To evaluate the special functions of DSA in interventional embolization therapy for uterine fibroids. Methods The special functions of DSA, including 3D-DSA, the optimal working position and road-mapping technique, were utilized in performing interventional embolization therapy for uterine fibroids in twenty-six cases (experimental group). Routine DSA angiography was employed in twenty cases (control group). The volume of contrast media used, the time of completing the interventional procedure and the total fluoroscopic time in two groups were compared and the results were analyzed. Results The difference in the volume of contrast agent used and in the total fluoroscopic time between two groups was statistically significant (P 0.05). Conclusion In treating uterine fibroids with interventional embolization, the use of the special functions of DSA can reduce the manipulation time and lower the operation risk. Moreover, the technique of visible 3D reconstruction image is of great significance in guiding the procedure.

  15. The Fuzzy Logic Method for Simpler Forecasting

    Directory of Open Access Journals (Sweden)

    Jeffrey E. Jarrett

    2011-08-01

    Full Text Available Fildes and Makridakis (1998, Makridakis and Hibon (2000, and Fildes (2001 indicate that simple extrapolative forecasting methods that are robust forecast equally as well or better than more complicated methods, i.e. Box-Jenkins and other methods. We study the Direct Set Assignment (DSA extrapolative forecasting method. The DSA method is a non-linear extrapolative forecasting method developed within the Mamdani Development Framework, and designed to mimic the architecture of a fuzzy logic control system. We combine the DSA method Winters' Exponential smoothing. This combination provides the best observed forecast accuracy in seven of nine subcategories of time series, and is the top three in terms of observed accuracy in two subcategories. Hence, fuzzy logic which is the basis of the DSA method often is the best method for forecasting.

  16. DSA应用于颅内复杂动脉瘤介入杂交手术中的临床价值%Clinical Value of DSA in Interventional Hybrid Operation of Intracranial Complex Aneurysms

    Institute of Scientific and Technical Information of China (English)

    杜希剑; 余开湖; 章凯敏; 于加省

    2016-01-01

    Objective To investigate the effects of interventional hybrid operation in the treatment of intracranial complex aneurysms and to observe the evaluation value of digital subtraction angiography (DSA) before and after surgical treatment.Methods 17 patients (23 aneurysms) with intracranial aneurysms were treated with SolitaireAB stent assisted coil embolization. The differences in the detection rate of intracranial aneurysms between 2D digital subtraction angiography (2D-DSA) and 3D digital subtraction angiography (3D-DSA) were compared.Results Among the 17 patients with pathologically confirmed intracranial aneurysms, 16 patients were detected by 2D-DSA. 1 case of small bleeding blister like wide carotid aneurysm was missed diagnosed because the lesion was too small and the accuracy rate was 94.12%. All were detected by 3D-DSA and the accuracy rate was 100.0%. However, there was no significant difference between the two detection methods (t=1.030, P=0.310). 15 cases of wide carotid aneurysms reached tight embolization during operation; 2 patients with large wide carotid aneurysms without ruptured internal carotid artery were given relatively looser packing. 1 patient with wide carotid aneurysm in bilateral middle cerebral artery was treated with craniotomy for removing hematoma and decompressive craniectomy after embolotherapy because of preoperative massive hemorrhage. There were no deaths in the whole group. The patients were followed up for 3-30 months after operation. 16 patients returned to work and 1 patients were in persistent coma (treated for 3 months). DSA reexamination found that 16 cases of aneurysms disappeared and there still was blood perfusion in tumor cavity of 1 patients with wide internal carotid aneurysms treated with loose packing but the aneurysm was not enlarged.Conclusion Stent assisted coil embolization technique can effectively improve the success rate of embolotherapy for treating intracranial complex wide carotid aneurysms. It can

  17. Multidetector CT and DSA research of beagle′s celiac artery anatomy%比格犬腹腔动脉解剖的多层螺旋 CT和 DSA 研究

    Institute of Scientific and Technical Information of China (English)

    迪里木拉提·巴吾冬; 巴哈提·哈立亚; 别克木拉提·马合木提; 赵建卿

    2013-01-01

    Objective To assess the anatomical features of beagle′s celiac artery by multidetector CT angi-ography (MDCTA) and digital subtraction angiography (DSA) .Methods 15 adult beagles were examined by multidetector CT (MDCT ) .Celiac artery was catheterized via a superficial branch access of femoral ar-tery and performed selective angiography .Results MDCT and angiography were performed successfully in all animals ,with a success rate of 100% (15/15) .Beagle′s celiac artery anatomy is very similar to the hu-man′s .Similarities between the beagle′s and human celiac artery anatomy revealed by MSCT and DSA in-clude:(1) The celiac artery arises from the aorta at the same level ;(2) After arising from the anterior wall of the aorta ,the celiac artery runs forwardly and gives branches ;(3) Although Left gastric artery ari-ses from the proximal splenic artery in beagle ,it is still a branch of the celiac artery ,therefore ,three branches of celiac artery ,the hepatic artery ,splenic artery and left gastric artery were the same with hu-man′s .The differences are :(1) Left gastric artery arise from the proximal splenic artery ;(2) Gastroduo-denal artery arise at the liver hilar .The proper hepatic artery is very short or absent .In 3 dogs ,right he-patic artery rises before the gastroduodenal artery (20% ) .Conclusion The study confirms anatomical similarity between the beagle′s celiac artery and the human celiac artery .It has broad application prospects in animal interventional studies of the liver ,spleen ,pancreas ,stomach and other organs .%目的:采用多层螺旋CT血管造影(MDCTA)和数字减影血管造影(DSA)评价比格犬腹腔动脉及其主要分支的解剖学特点。方法成年比格犬15只,分别进行多层螺旋C T (M DC T )检查和在直视下行经股动脉浅表分支选择性腹腔动脉插管及DSA造影术,观察腹腔干其主要分支的起源和走行并测量直径和长度。结果15只比格犬15条股动脉

  18. Single-session combined therapy with chemoembolization and DSA-CT guided radiofrequency ablation in hepatocellular carcinoma larger than 5 cm:A primary clinical study%肝动脉化疗栓塞联合同步DSA-CT引导下射频消融治疗大肝癌的临床研究

    Institute of Scientific and Technical Information of China (English)

    王志军; 王茂强; 段峰; 宋鹏; 刘凤永; 常中飞; 王燕; 阎洁羽; 李凯

    2014-01-01

    ObjectiveTo assess the safety and efifcacy of single-session combined therapy with transcatheter arterial chemoembolization (TACE) and DSA-CT guided radiofrequency ablation (RFA) in hepatocellular carcinoma (HCC) larger than 5 cm.Methods A total of 21 patients were treated with TACE immediately followed by DSA-CT-guided RFA. Rate of technical success, local-regional tumor response, recurrence-free survival time, survival rate and complications were evaluated at follow-up images and AFP (α-fetoprotein).Results Technical success was achieved in all 25 visible HCC. No major complications was observed in any patient. Nineteen patients were complete response (CR) and 2 were partial response (PR) after the 1st months. Coagulation necrosis was the major appearance. CR occupied 90.48% (19/21). PR occupied 9.52% (2/21). Local-regional tumor response in solitary nodular lesions (17/17, 100%) was superior to multiple nodular lesions (2/4, 50.00%;P=0.034). During follow-up period, mean recurrence-free survival time was 11.8±6.0 months in 19 cases with CR. The estimated overall survival rate at 6, 12 months and 18 months was 100%.Conclusions Single-session combined therapy with TACE and DSA-CT guided RFA in large hepatocellular carcinoma was safe and effective, especially for solitary nodular lesions.%目的:评估肝动脉化疗栓塞(TACE)联合同步DSA-CT引导下射频消融(RFA)治疗大肝癌(肿瘤最大直径≥5 cm)的安全性和疗效。方法2010年1月~2012年3月21例原发性肝细胞癌患者接受同步联合治疗。术后定期进行影像学检查并复查甲胎蛋白,评估联合技术成功率、局部肿瘤治疗反应、无疾病复发时间、患者存活情况和技术相关并发症。结果技术成功率100%,无重要并发症发生。介入术后1个月复查,病灶完全缓解19例(19/21,90.48%)、部分缓解2例(2/21,9.52%)。肿瘤坏死以凝固性坏死为主。在局部灭活肿瘤方面,

  19. DSA对颅内动脉瘤形态与体积的诊断价值%The diagnosis of morphology and volume in intracranial aneurysms by DSA

    Institute of Scientific and Technical Information of China (English)

    李慧; 何文龙; 常祖宽

    2016-01-01

    目的:探讨DSA对颅内动脉瘤的形态与体积的诊断,统计各型颅内动脉瘤的检出率,为手术及血管内介入治疗提供直观依据。方法回顾性分析2009-01—2015-01我院120例经CTA、MRA、DSA确诊的颅内动脉瘤患者,CTA、M RA确诊者再行DSA检查,根据颅内动脉瘤形态学特点及大小,总结各型的检出率。结果根据颅内动脉瘤形态学特点分型:囊状动脉瘤(包括圆形、椭圆形、球形、葫芦形、漏斗形、哑铃型、分叶形、多角形、腊肠形、不规则形)检出率94.0%,梭形动脉瘤检出率4.2%,夹层动脉瘤检出率0.8%。根据颅内动脉瘤大小:小动脉瘤(直径<0.5 cm )检出率47.9%,一般动脉瘤(0.5 cm≤直径<1.5 cm )检出率42.2%,大型动脉瘤(1.5 cm≤直径<2.5 cm )检出率7.7%,巨型动脉瘤(直径≥2.5 cm )检出率2.2%。结论 DSA对动脉瘤形态与体积作出准确诊断与直观显现,为手术及血管内介入治疗提供依据。%Objective To investigate the diagnosis of intracranial aneurysms by DSA ,and the detection rate of intracra‐nial aneurysms. Methods A retrospective analysis was made on 120 patients with intracranial aneurysms from January 2009 to January 2015 in our hospital by the CTA ,MRA ,and DSA. Patient was given DSA diagnosis after CTA ,MRA confirmed.We summed up the detection rate of each type according to intracranial aneurysms characteristic morphological characteristics and size. Results According to the morphological characteristics of intracranial aneurysms ,the detection rate of saccular an‐eurysm (including circular ,oval ,spherical ,gourd-shaped ,funnel-shaped ,dumbbell-shaped ,sub-leaf ,polygonal ,sausage-shaped ,irregular-shaped) accounted for 94.0% ,spindle aneurysm accounted for 4.2% ,dissecting aneurysm accounted for 0.8%. According to the size of intracranial aneurysm ,the detection rate of small aneurysm (diameter<0.5 cm) was 47

  20. Comparative Study in the Diagnosis of Intracranial Aneurysms with 64 Slice CTA-and 3D DSA%64层CTA-MIP、CTA-VR与3D-DSA对颅内动脉瘤诊断价值的对比研究

    Institute of Scientific and Technical Information of China (English)

    刘善平

    2012-01-01

    目的 对比评价64层螺旋CT最大密度投影(CTA-MIP),CTA容积再现(CTA-VR)与三维数字血管造影(3D-DSA)对颅内动脉瘤(CA)的诊断价值.资料与方法 回顾性分析32例经手术及DSA确诊的CA 64层CT血管成像资料,并与DSA进行对照.结果 32例共40个动脉瘤,CTA-MIP发现35个动脉瘤,CTA-VR发现37个动脉瘤,3D-DSA发现39个动脉瘤.40个动脉瘤中11个位于后交通动脉,16个位于大脑中动脉,4个位于基底动脉,1个位于椎动脉,2个位于大脑前动脉,3个位于大脑后动脉,3个位于颈内动脉.3 D-DSA与CTA比较,差异无统计学意义.结论 在CA影像学诊断上,CTA-MIP、CTA-VR和3D-DSA各有优势,CTA可作为外科治疗或介入治疗的筛选方法.%Objective To evaluate the role of 64 slice computed tomography angiography maximum intensity projection (CTA,MIP) , computed tomography angiography volume rendering (CTA,VR) and 3 dimensional digital subtraction angiogtaphy(3D-DSA) ) in the diagnosis of intracranial aneurysms. Materials and Methods The CT and DSA imaging findings of 32 patients with aneurysms were retrospectively analyzed and compared. Results 40 aneurysms in 32 patients were found by DSA and/or operation. 35 aneurysms were found by CTA MIP. 37 aneurysms were found by CTA VR. 39 aneurysms were found by DSA. 11 aneurysms were at posterior communicating artery, 16 aneurysms at middle cerebral artery, 4 aneurysms at basilar artery, 1 aneurysms at vertebary artery, 2 aneurysms at anterior cerebral artery, 3 aneurysms at posterior cerebral artery, 3 aneurysms at internal carotid artery. There was no significant difference in detecting aneurysms between CTA and 3D DSA. Conclusion CTA MIP, CTA VR and 3D-DSA examination have their own advantage in diagnosis of intracranial aneurysms. CTA can be used as the method in screening intracranial aneurysms for surgery and interventional therapy.

  1. B$_{s}^{0}$ --> D$_{s}^{-}$a$_{1}^{+}$ decay channel in the B$_{s}^{0}$-mixing studies

    CERN Document Server

    Bannikov, A V; Silagadze, Z K

    1995-01-01

    The usefulness of the B_s^0 \\to D_s^-a_1^+, D_s^- \\to \\phi \\pi^- \\to K^+K^-\\pi^-, a_1^+ \\to \\rho^0 \\pi^+ \\to \\pi^+ \\pi^- \\pi^+ decay chain is investigated for the B_s-reconstruction in the future ATLAS B_s-mixing experiment. It is shown that this decay channel is almost as suitable for this purpose as previously studied B_s^0 \\to D_s^-\\pi^+.

  2. Clinical Application of MRI and DSA in the Diagnosis of TOBS%MRI联合DSA在基底动脉尖综合征诊断中的临床应用

    Institute of Scientific and Technical Information of China (English)

    周勇; 徐树军; 朱淼; 白海涛

    2011-01-01

    目的 探讨MRI联合DSA在基底动脉尖综合征(top of the basilar syndrome,TOBS)诊断及治疗中的应用价值.方法 回顾性分析21例TOBS患者的MRI和DSA检查资料,观察MRI显示病变的分布范围和DSA显示椎基底动脉血管结构.结果 梗死灶分布于两侧丘脑、中脑、小脑、枕叶、颞叶.呈对称性病变13例,单侧分布8例.76.2%(16/21)的患者中存在椎动脉和基底动脉形态异常,23.8%(5/21)椎、基底动脉DSA检查未见明显异常.结论 MRI联合DSA检查为临床提供较为完整的诊断信息,可以作为TOBS筛选和首选的诊断方法.%Objective To explore the diagnosis and treatment application of MRl and DSA of TOBS.Methods 21 cases with TOBS using MRI and DSA inspection data were retrospectively analyzed so as to observe the distribution range of pathological change,the void flow of vertebral or basilar artery and the structure of vertebral or basilar artery.Results The infarction lies in the both sides of the thalamus,midbrain,cerebellum ,occipital lobe,and temporal lobe.There were 13 cases with symmetrical infraction and 8 cases with unilateral infarction.76.2% (16/2l)of the survivals showed abnormal performance in vertebral and basilar artery,23.8% (5/21)had no significant abnormalities in vertebral and basilar artery after DSA examination.Conclusion The joint inspection of MRI and DSA provides comprehensive clinical information,which can be used as the preferred TOBS screening and diagnostic methods.

  3. Clnical Study of the Treatment of Patients with a Metastatic Spinal Tumor by Percutaneous Vertebroplasty under the Guidance of DSA

    Institute of Scientific and Technical Information of China (English)

    Zuozhang Yang; Yanbin Xiao; Ming Peng; Yu Li; Li Luan; Jianbo Xu; Congguo Jin; Pengiie Liu; Tao Yuan; Baosheng Qian; Jinyu Zhang; Wengzhong Li; Jianlin Li

    2005-01-01

    OBJECTIVE To explore the clinical effect in patients with metastatic spinal tumors treated by percutaneous vertebroplasty (PVP) under the guidance of digital subtraction angiography (DSA).METHODS A total of 110 cases with a metastatic spinal tumor were divided into 55 cases in the treatment group (group A ) and 55 cases in the control group (group B ). The general clinical data were statistically analyzed before treatment with the parameters showing no differences.Group A was treated by PVP and chemotherapy as well. Group B was treated by the regular chemotherapy and regular radiation therapy. The same chemotherapy program was used for the same type of disease. All cases were provided with a follow-up survey for 12 months. During the follow-up survey, changes in the quality of life, in evaluation of bone pain and in vertebral column stability as well as adverse reactions were observed.RESULTS The statistics showed a significant difference between the 2 groups, specifically changes in the quality of life and evaluation of bone pain (P<0.05, t1=2.74, t2=9.02). During the follow-up survey, 5 cases in group A died of other organ complilcations, the death rate being 9.1% (5out of 55), but all survived more than 3 months following PVP. The vertebrai columns of the survivors were kept stable, with no pathological fractures occurring in the vertebral bodies filled with bone cement, there were no obvious adverse reactions, and no paraplegia occurred. Thirteen cases died in group B with a death rate of 23.6% (13 out of 55). Pathological compression fractures in the vertebral bodies occurred in 30 cases, and 12 cases of complicated paraplegia were noted. The incident rate of paraplegia was 21.8% (12 out of 55).CONCLUSION PVP is a simple operation causing only small wounds and few complications. It can effectively alleviate pain of metastatic spinal tumors in patients, improve quality of life and reduce the incidence rate of paraplegia.

  4. Projected discrete ordinates methods for numerical transport problems

    Energy Technology Data Exchange (ETDEWEB)

    Larsen, E.W.

    1985-01-01

    A class of Projected Discrete-Ordinates (PDO) methods is described for obtaining iterative solutions of discrete-ordinates problems with convergence rates comparable to those observed using Diffusion Synthetic Acceleration (DSA). The spatially discretized PDO solutions are generally not equal to the DSA solutions, but unlike DSA, which requires great care in the use of spatial discretizations to preserve stability, the PDO solutions remain stable and rapidly convergent with essentially arbitrary spatial discretizations. Numerical results are presented which illustrate the rapid convergence and the accuracy of solutions obtained using PDO methods with commonplace differencing methods.

  5. Microsurgical anatomy and DSA research about venous anastomosis of superficial cerebral veins%大脑浅静脉吻合静脉的显微解剖与数字减影血管造影观察

    Institute of Scientific and Technical Information of China (English)

    顾英豪; 宋薇; 孙虎

    2015-01-01

    目的 探讨正常成人大脑浅静脉吻合静脉的分布情况及其临床意义.方法 回顾性分析50例正常成人数字减影血管造影(DSA)静脉相片,并观察测量大脑浅静脉吻合静脉形态.同时对15具(30侧)经血管内灌注染料的成人尸头的大脑浅静脉吻合静脉显微镜下解剖观察.结果 上吻合静脉(Trolard静脉)和下吻合静脉(Labbe静脉)是大脑浅静脉的主要吻合静脉,50侧DSA静脉相共发现Trolard静脉55条,左侧27条,右侧28条,经显微解剖的30侧大脑半球共发现Trolard静脉34条,左侧18条,右侧16条.50侧DSA静脉相共发现Labbe静脉51条,左侧25条,右侧26条,30侧大脑半球共发现Labbe静脉31条,左侧15条,右侧16条.结论 大脑浅静脉吻合静脉变异较大,DSA静脉相显示与显微解剖发现基本相符,术前DSA检查有利于术中大脑浅静脉吻合静脉的保护.%Objective To investigate the distribution and clinical significance about venous anastomosis of superficial cerebral vein in normal adult.Methods The digital subtraction angiography (DSA) images of the venous phase from 50 normal adults were retrospectively analyzed,and the morphology of venous anastomosis of superficial cerebral veins was observed and measured.While venous anastomosis of superficial cerebral veins of 15 (30 sides) cadaveric heads was observed through blood vessel perfusion.Results Trolard vein and Labbe vein were the main venous anastomosis of superficial cerebral veins.A total of 55 Trolard veins were found out of 50 sides DSA venous phase images,including left 27,right 28;34 Trolard veins,left 18,right 16,were found from the 30 sides of the brain hemispheres.51 Labbe veins,left 25,right 26,were found from the 50 sides DSA venous phase images,and 31 Labbe veins,left 15,right 16,were found from the 30 sides of the brain hemispheres.Condasions Venous anastomosis of superficial cerebral veins is variable.The DSA venous phase image is consistent with the microscopic

  6. Inflammatory aortic arch syndrome: contrast-enhanced, three-dimensional MR - angiography in stenotic lesions; Entzuendliches Aortenbogensyndrom: Stenosediagnostik mittels kontrastmittelverstaerkter 3D-MR-Angiographie im Vergleich mit der DSA

    Energy Technology Data Exchange (ETDEWEB)

    Both, M.; Mueller-Huelsbeck, S.; Biederer, J.; Heller, M.; Reuter, M. [Universitaetsklinikum Schleswig-Holstein, Kiel (Germany). Klinik fuer Diagnostische Radiologie; Reinhold-Keller, E.; Gross, W.L. [Rheumaklinik Bad Bramstedt GmbH (Germany)

    2004-01-01

    Purpose: To determine the value of contrast-enhanced, three-dimensional MR angiography for the evaluation of stenotic and occlusive vascular lesions in inflammatory aortic arch syndrome. Materials and Methods: 14 patients with inflammatory aortic arch syndrome (giant cell arteritis: n = 8, Takayasu arteritis: n = 4, ankylosing spondylitis: n = 1 sarcoidosis: n = 1) underwent MR angiography of the aortic arch and the supra-aortic vessels (n = 15,2 patients were examined twice) and of the abdominal aorta (n = 2). MRA was performed using a 3D-FLASH sequence (TR/TE 4.6/1.8 ms, flip angle 30 ) on a 1.5T system. MRA imaging was compared with the findings of DSA, which served as gold standard. Results: In a total of 467 examined vascular territories, DSA revealed 50 stenoses and 35 occlusions. All lesions were detected by MRA. In 23 segments, the degree of stenosis was overestimated by MRA. Sensitivity and specificity of MRA were 100% and 94,3%, positive and negative predictive values were 73.6 and 100%, and the accuracy was 95,1%. Conclusions: Despite a tendency to overestimate stenoses, contrast-enhanced three-dimensional MR angiography is a valid, non-invasive technique in the assessment of inflammatory aortic arch syndrome. (orig.) [German] Ziel: Bestimmung der Aussagekraft der kontrastmittelverstaerkten 3D-Magnetresonanzangiographie bei der Bewertung stenosierender und okkludierender Gefaessveraenderungen im Rahmen des entzuendlichen Aortenbogensyndroms. Material und Methoden: Bei 14 Patienten mit entzuendlichem Aortenbogensyndrom (Arteriitis temporalis: n = 8, Takayasu-Arteriitis: n = 4, Morbus Bechterew: n = 1, Sarkoidose: n = 1) erfolgte eine MRA des Aortenbogens und der supraaortalen Aeste (n = 15, darunter zwei Doppeluntersuchungen) sowie der Aorta abdominalis (n = 2). Zur Anwendung kam eine kontrastmittelverstaerkte 3D-FLASH-Sequenz (TR/TE 0,4/1,8 ms, Flipwinkel 30 ) an einem 1,5 Tesla-System. Die Befunde der MRA wurden mit der DSA als Referenzmethode

  7. ECG-triggered non-contrast-enhanced MR angiography (TRANCE) versus digital subtraction angiography (DSA) in patients with peripheral arterial occlusive disease of the lower extremities

    Energy Technology Data Exchange (ETDEWEB)

    Gutzeit, Andreas [Cantonal Hospital Winterthur, Department of Radiology, Winterthur (Switzerland); Paracelsus Medical University Salzburg, Department of Radiology, Salzburg (Austria); Sutter, Reto [Cantonal Hospital Winterthur, Department of Radiology, Winterthur (Switzerland); University Hospital Balgrist, Department of Radiology, Zurich (Switzerland); Froehlich, Johannes M.; Roos, Justus E.; Sautter, Thomas; Schoch, Erik; Giger, Barbara; Weymarn, Constantin von; Binkert, Christoph A. [Cantonal Hospital Winterthur, Department of Radiology, Winterthur (Switzerland); Wyss, Michael [University and ETH Zurich, Institute for Biomedical Engineering, Zurich (Switzerland); Graf, Nicole [University Hospital of Zurich, Clinical Trials Center, Center for Clinical Research, Zurich (Switzerland); Jenelten, Regula [Cantonal Hospital Winterthur, Department of Angiology, Winterthur (Switzerland); Hergan, Klaus [Paracelsus Medical University Salzburg, Department of Radiology, Salzburg (Austria)

    2011-09-15

    To prospectively determine the diagnostic value of electrocardiography-triggered non-contrast-enhanced magnetic resonance angiography (TRANCE) of the lower extremities including the feet versus DSA. All 43 patients with symptomatic peripheral arterial occlusive disease (PAOD) underwent TRANCE before DSA. Quality of MRA vessel depiction was rated by two independent radiologists on a 3-point scale. Arterial segments were graded for stenoses using a 4-point scale (grade 1: no stenosis; grade 2: moderate stenosis; grade 3: severe stenosis; grade 4: occlusion). Findings were compared with those of DSA. In the 731 vessel segments analysed, intra-arterial DSA revealed 283 stenoses: 33.6% moderate, 16.6% severe and 49.8% occlusions. TRANCE yielded a mean sensitivity, specificity, positive and negative predictive value and diagnostic accuracy to detect severe stenoses or occlusions of 95.6%, 97.4%, 87.2%, 99.2%, 97.1% for the thigh segments and 95.2%, 87.5%, 83.2%, 96.6%, 90.5% for the calf segments. Excellent overall image quality was observed for TRANCE in 91.4% versus 95.7% (DSA) for the thigh and in 60.7% versus 91.0% for the calves, while diagnostic quality of the pedal arteries was rated as insufficient. TRANCE achieves high diagnostic accuracy in the thigh and calf regions, whereas the pedal arteries showed limited quality. (orig.)

  8. Application of Combination of MRI with DSA in Diagnosis of TOBS%MRI联合DSA在基底动脉尖综合征诊断中的价值

    Institute of Scientific and Technical Information of China (English)

    朱正庭; 张玥玥; 高娟; 郑玲

    2012-01-01

    目的:探讨分析核磁共振(MRI)联合数字减影脑血管造影(DSA)在基底动脉尖综合征(TOBS)诊断及治疗中的应用价值.方法:对某院自2009年3月至2011年6月收治的30例TOBS患者的MRI和DSA检查资料进行回顾性分析,观察MRI显示的痛变部位的分布范围和DSA显示的推-基底动脉血管结构.结果:梗死部位主要有中脑、丘脑、枕叶、脑桥、颞叶内侧面、胼胝体压部、基底节、侧脑室旁等.其中23例出现3处及以上病灶(23/30,76.7%),7例出现2处病灶(7/30,23.3%);20例出现双侧病灶(20/30,66.7%),10例为单侧病灶(10/30,33.3%).DSA检查显示椎-基底动脉血管异常,多表现为基底动脉(BA)、大脑后动脉(PCA)、椎动脉(VA)、小脑后下动脉(SCA)的狭窄或未显影.结论:MRI联合DSA检查可以为临床提供较为完整的诊断信息,能够作为TOBS筛选的诊断方法.%Objective To explore the diagnosis and treatment application of MRI and DSA on top of the basilar syndrome (TOBS). Methods Thirty TOBS cases accepted since March 2009 to June 2011 were chosen to undergo MRI and DSA inspection. Data were retrospectively analyzed so as to observe the distribution range of pathological change, the void flow of vertebral or basilar artery and the structure of vertebral of basilar artery. Results The infarction laid in such parts as midbrain, thalamus, occipital lobe, pons, medial temporal lobe, corpus callosum, basal ganglia, lateral side, etc. Twenty -three cases showed three or more infractions and 7 cases showed two infractions. There were 20 cases with symmetrical infraction (20/30, 66.7%) and 7 cases with unilateral infarction (10/30, 33.3%). DSA indicated the abnormal performance in vertebral and basilar artery, in which most were the stenosis or undeveloped of basikr artery(BA), posterior cerebral artery (PCA), vertebral artery (VA) and posterior inferior cerebellar artery (SCA). Conclusion The combined inspection by MRI and DSA may provide

  9. Clinical evaluation and design of network live broadcast system of DSA video streaming%DSA视频流网络直播系统的设计与临床评价

    Institute of Scientific and Technical Information of China (English)

    王斌杰; 张和平; 靳海英; 张帆; 李波

    2008-01-01

    Objective To evaluate the clinical feasibility of network live broadcast of digital subtraction angiography(DSA)video streaming.Methods DSA video streaming was captured by an advanced image capture board.MPEG-4 and Directshow framework were used for data compression and transmission.Data of DSA video streaming could be transmitted easily from server sender filter to client receiver filter according to TCP and UDP protocols.Images of 24 cases were captured,which were compared with images of DSA workstation by experienced doctors.The subiective evaluation criteria included the manifestition of normal and pathological blood vessels,and sharpness,contrast degree and real time efficiency of images.Results The delay time of live broadcast was less than one second in 100 M LAN.Among 24 cases,excellent imaging quality was got in 17 cases,good in 5 cases and midst in 2 cases.Conclusion Excellent images and synchronism of DSA video are achieved in this system.which can meet clinical requirements of diagnosis and synchronism.%目的 探讨DSA视频流网络直播临床应用的可行性.方法 DSA视频流由高性能的图像采集卡进行采集,利用动态图像专家组标准4(MPEG-4)压缩,结合微软的流媒体处理开发包DirectShow框架技术,通过服务器端的发送过滤器(filter)和客户端的接收filter,再利用网络传输层的传输控制协议(TCP)和用户数据报协议(UDP),实现DSA视频流的网络直播.对24例图像进行采集直播,由有经验的医师对客户端与DSA工作站的视频图像进行对比分析,主观评价每例图像的血管、病变影像特征的显示情况,以及图像的清晰度、对比度、实时有效性.结果 在100 M的局域网中,该方案直播的图像延迟时间≤1 s,24例视频图像中图像品质评价优17例,良5例,中2例.结论 该方案直播DSA视频流,图像清晰度好,延迟时间短,能够达到临床诊断与实时性要求.

  10. Renal Transplant Patients Biopsied for Cause and Tested for C4d, DSA, and IgG Subclasses and C1q: Which Humoral Markers Improve Diagnosis and Outcomes?

    Science.gov (United States)

    Cicciarelli, James C.; Chang, Youngil; Koss, Michael; Hacke, Katrin; Kasahara, Noriyuki; Burns, Kevin M.; Min, David I.; Naraghi, Robert; Shah, Tariq

    2017-01-01

    The association between donor specific antibodies (DSA) and renal transplant rejection has been generally established, but there are cases when a DSA is present without rejection. We examined 73 renal transplant recipients biopsied for transplant dysfunction with DSA test results available: 23 patients diffusely positive for C4d (C4d+), 25 patients focally positive for C4d, and 25 patients negative for C4d (C4d−). We performed C1q and IgG subclass testing in our DSA+ and C4d+ patient group. Graft outcomes were determined for the C4d+ group. All 23 C4d+ patients had IgG DSA with an average of 12,500 MFI (cumulative DSA MFI). The C4d− patients had average DSA less than 500 MFI. Among the patients with C4d+ biopsies, 100% had IgG DSA, 70% had C1q+ DSA, and 83% had complement fixing IgG subclass antibodies. Interestingly, IgG4 was seen in 10 of the 23 recipients' sera, but always along with complement fixing IgG1, and we have previously seen excellent function in patients when IgG4 DSA exists alone. Cumulative DSA above 10,000 MFI were associated with C4d deposition and complement fixation. There was no significant correlation between graft loss and C1q positivity, and IgG subclass analysis seemed to be a better correlate for complement fixing antibodies in the C4d+ patient group.

  11. Evaluation of angiographic delayed vasospasm due to ruptured aneurysm in comparison with cerebral circulation time measured by IA-DSA

    Energy Technology Data Exchange (ETDEWEB)

    Okada, Yoshikazu; Shima, Takeshi; Nishida, Masahiro; Yamane, Kanji; Okita, Shinji; Hatayama, Takashi; Yoshida, Akira; Naoe, Yasutaka; Shiga, Naoko (Chugoku Rosai Hospital, Hiroshima (Japan))

    1994-05-01

    Delayed vasospasm due to ruptured aneurysm has been basically evaluated by angiographic changes in contrast to clinical features such as delayed ischemic neurological deficits (DIND). However, the discrepancies between angiographic and clinical findings have been pointed out. In this study, angiographic changes and cerebral circulation time in ruptured aneurysms were simultaneously investigated with IA-DSA. Thirty-two patients, who had ruptured aneurysms at the anterior circle of Willis and neck clippings at the acute stage, were investigated. Carotid angiogram was performed with IA-DSA on the 7-13th day after the attack. Angiographic changes were evaluated by Fischer's classification and circulation time was calculated in the following way. A time-density curve was obtained at the two ROI's: the C3-C4 portion and the rolandic vein. Circulation time was defined by the difference between the time showing peak optical density at the carotid and the venous portion. The control value of this circulation time obtained from 20 cases with non-rupture aneurysm and epilepsy was 3.4 sec (53 year old) on the average. X-ray CT scan examination was performed at the same time and clinical features were observed every day. Angiographically, 3 cases were free from vasospasm, 18 cases were found to present slight to moderate vasospasm, and 11 cases showed severe vasospasm. Circulation time in patients with no spasm was 3.6 seconds, in patients with slight to moderate vasospasm it was 4.3 seconds and in patients with severe vasospasm it was 6.8 seconds. Ten patients showing cerebral infarction on CT scans demonstrated significantly long circulation time, 7.0 seconds on the average. And all patients having severe vasospasm with circulation time more than 6 seconds presented DIND such as hemiparesis. (author).

  12. Mesa redonda: Argentina en proyectos globales de investigaciones espaciales y astronómicas. Uso científico de la Antena de Espacio Profundo DSA 3

    Science.gov (United States)

    Colazo, M.

    2016-08-01

    Argentine has 10 percent of the operative time available for the DSA 3 Antenna of the European Space Agency, installed in Malargüe, Mendoza. Here we present the history of the project and the current activities for the scientific use of the antenna.

  13. Follow-up of intracranial aneurysms treated by a WEB flow disrupter: a comparative study of DSA and contrast-enhanced MR angiography.

    Science.gov (United States)

    Mine, Benjamin; Tancredi, Illario; Aljishi, Ali; Alghamdi, Faisal; Beltran, Margarita; Herchuelz, Maxime; Lubicz, Boris

    2016-06-01

    To compare contrast-enhanced MR angiography (CE-MRA) and DSA for the follow-up of intracranial aneurysms (IAs) treated with the Woven EndoBridge embolization system DL (WEB DL; Sequent Medical, Aliso Viejo, California, USA). We retrospectively identified all patients treated with a WEB DL between November 2010 and February 2013 in 2 hospitals. The IA occlusion was graded on follow-up CE-MRA and DSA by 4 independent readers and by 2 readers reaching a consensus, respectively. Interobserver agreement for MRA and intertechnique agreement was evaluated by calculating linear weighted κ. Fifteen patients with 16 IAs were included. Mean delay between MRA and DSA was 2 months (range 0-16 months). Interobserver agreement for MRA was substantial to almost perfect (κ=0.686-0.921; mean κ=0.809). Intertechnique agreement was moderate to substantial (κ=0.579-0.724; mean κ=0.669). Only three out of five inadequately occluded IAs were detected by MRA. CE-MRA is a useful tool for the follow-up of IAs treated with a WEB DL. However, early follow-up with DSA remains mandatory to detect inadequately occluded IAs. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  14. The Velues of CTA in Diagnosing Intracranial Aneurysms and Collating Analysis with DSA%CTA诊断颅内动脉瘤的价值及与DSA对照分析

    Institute of Scientific and Technical Information of China (English)

    梁满球; 郑晓林; 陈妙玲; 肖利华; 朱纯生

    2014-01-01

    目的:探讨CTA诊断颅内动脉瘤的价值和提高诊断的敏感性。方法回顾性分析126例拟诊为颅内动脉瘤CTA表现,对颅内动脉瘤的部位及大小进行分组观察,与DSA对照,统计CTA对颅内动脉瘤的正确检出率,对漏诊、误诊病例进行分析。结果颅内动脉瘤共124例,共152个。CTA正确检出113例,正确率为91.1%;正确检出动脉瘤140个,正确率为92.1%。12个动脉瘤漏诊,其中多发性、<3mm和3-5mm组别动脉瘤CTA漏诊数较高,与DSA比较,检出率较低,具有统计学意义。结论 CTA诊断颅内动脉瘤的正确率较高,但多发性、较小的动脉瘤较DSA漏诊率高,如在诊断中加以注意,能提高CTA诊断动脉瘤的敏感性。%Objective To evaluate values and sensitivity of CTA diagnosing intracranial aneurysms. Methods The CTA manifestations of dubiously intracranial aneurysms in 126 cases were retrospectively analysed and location and size of intracranial aneurysms were grouped and observed. Collating with DSA, correct rate of CTA diagnosing intracranial aneurysms were accounted and the cases leaked and mistaked were analysed. Results In 124 cases suffered from intracranial aneurysms including 152 lesions, 113 cases and 140 lesions were detected by CTA which correct rate was respectively 91.1% and 92.1%. Twelve lesions of intracranial aneurysms weren'nt detected by CTA in which multi-lesions, sizes of <3mm and 3-5mm intracranial aneurysms were main leaked part. The detceted rate of CTA was lower than of DSA and it had statistical significance. Conclusions The correct rate of CTA diagnosing intracranial aneurysms was high but leaked rate of CTA in multi-lesions, small sizes was high by compared DSA. If more notice in some aspect, sensitivity of CTA diagnosing intracranial aneurysms can be promoted.

  15. Hepatic Arterial Configuration in Relation to the Segmental Anatomy of the Liver; Observations on MDCT and DSA Relevant to Radioembolization Treatment

    Energy Technology Data Exchange (ETDEWEB)

    Hoven, Andor F. van den, E-mail: a.f.vandenhoven@umcutrecht.nl; Leeuwen, Maarten S. van, E-mail: m.s.vanleeuwen@umcutrecht.nl; Lam, Marnix G. E. H., E-mail: m.lam@umcutrecht.nl; Bosch, Maurice A. A. J. van den, E-mail: mbosch@umcutrecht.nl [University Medical Center Utrecht, Department of Radiology and Nuclear Medicine (Netherlands)

    2015-02-15

    PurposeCurrent anatomical classifications do not include all variants relevant for radioembolization (RE). The purpose of this study was to assess the individual hepatic arterial configuration and segmental vascularization pattern and to develop an individualized RE treatment strategy based on an extended classification.MethodsThe hepatic vascular anatomy was assessed on MDCT and DSA in patients who received a workup for RE between February 2009 and November 2012. Reconstructed MDCT studies were assessed to determine the hepatic arterial configuration (origin of every hepatic arterial branch, branching pattern and anatomical course) and the hepatic segmental vascularization territory of all branches. Aberrant hepatic arteries were defined as hepatic arterial branches that did not originate from the celiac axis/CHA/PHA. Early branching patterns were defined as hepatic arterial branches originating from the celiac axis/CHA.ResultsThe hepatic arterial configuration and segmental vascularization pattern could be assessed in 110 of 133 patients. In 59 patients (54 %), no aberrant hepatic arteries or early branching was observed. Fourteen patients without aberrant hepatic arteries (13 %) had an early branching pattern. In the 37 patients (34 %) with aberrant hepatic arteries, five also had an early branching pattern. Sixteen different hepatic arterial segmental vascularization patterns were identified and described, differing by the presence of aberrant hepatic arteries, their respective vascular territory, and origin of the artery vascularizing segment four.ConclusionsThe hepatic arterial configuration and segmental vascularization pattern show marked individual variability beyond well-known classifications of anatomical variants. We developed an individualized RE treatment strategy based on an extended anatomical classification.

  16. Direct finite element computation software CSR-DSA of China Classification Society%中国船级社有限元直接计算软件CSR-DSA

    Institute of Scientific and Technical Information of China (English)

    刘玉川; 金立明; 王丽荣; 章伟星

    2010-01-01

    鉴于国际船级社协会(International Association of Classification Societies,IACS)2006年推出的散货船、双壳油船共同结构规范CSR-BC/OT的复杂性,为减小用人工方法施加载荷、处理结果和扣除腐蚀等的工作量,降低出错率,中国船级社(China Classification Society,CCS)开发出有限元直接计算软件CSR-DSA.该软件以MSC Patran为平台,并使用PCL开发实现自动扣除腐蚀,施加载荷,校核屈服、屈曲、疲劳和细化网格等功能,覆盖CSR-BC/OT的大部分直接强度分析要求.CSR-DSA已得到广泛应用,很大程度上解决该规范带来的工作量大和计算易出错等问题,可以大大缩短船舶设计和审图的工作周期、提高计算准确性.

  17. Analysis of the anatomical relationship between the uterine artery and the bony landmarks in cesarean scar pregnancy by CT angiography and digital subtraction angiography%剖宫产瘢痕妊娠子宫动脉开口位置与骨性标志关系的 CT 血管成像与DSA 研究

    Institute of Scientific and Technical Information of China (English)

    熊浪; 王进华; 孙进; 邓美香; 郑伟增; 肖新兰

    2015-01-01

    目的:利用 CTA 与 DSA 技术,采用骶髂垂直分段定位法探讨剖宫产术后子宫瘢痕妊娠(CSP)患者子宫动脉开口位置与骨性解剖标志的关系。方法回顾性分析2013年10月—2014年6月浙江大学医学院附属妇产科医院收治的91例 CSP 患者的临床资料和 CTA、DSA 影像学资料。患者年龄23~44岁,平均(32.7±4.2)岁。在骶髂关节骶骨面中,以骶骨的最高点(如左侧 A 点)与髂骨左右两侧的最低点(a、b)为骨盆骨性解剖标志。采用骶髂垂直分段定位法连接 a、b 两点做一水平线 ab,从 A 点向 ab 水平线做一垂线,交点为 D 点,B、C 等分 AD,将骶髂垂直等分为 AB、BC、CD 和 D点远端4段,在患者 CTA 与 DSA 图片上,观察统计患者双侧子宫动脉开口位置在各段的分布情况。结果91例182支子宫动脉中,3支子宫动脉已结扎,CTA 与 DSA 均未见其显示;179支子宫动脉显影,子宫动脉开口位置左侧低于右侧,左侧在 AB、BC、CD 及 D 点远端的比例为0%(0)、3.3%(3/90)、70.0%(63/90)及26.7%(24/90),右侧的比例为0%(0)、11.2%(10/89)、85.4%(76/89)及3.4%(3/89),左右两侧均以 CD 段所占比例最多,两侧在各段分布构成情况差异有统计学意义(χ2=22.618,P <0.01)。结论 CSP 患者子宫动脉开口位置在骶髂各段中分布具有一定的特征,当 CSP患者子宫动脉栓塞治疗无法准确判断子宫动脉开口位置时,利用骶髂垂直分段定位法可为介入治疗提供新的影像学指导和参考。%Objective To investigate the anatomical relationship between the uterine artery and the adjacent bony landmarks in cesarean scar pregnancy ( CSP ) with the method of sacroiliac vertical segmentation localization using CT angiography ( CTA ) and digital subtraction angiography ( DSA ). Methods From October 2013 to June 2014, 91 patients of CSP were examined by CTA and DSA in Department of Radiology of the Women′s Hospital of Medicine Zhejiang University. The

  18. Brain arteriovenous malformation diagnosis: value of time-resolved contrast-enhanced MR angiography at 3.0T compared to DSA

    Energy Technology Data Exchange (ETDEWEB)

    Machet, A.; Kadziolka, K.; Robin, G.; Lanoix, O.; Pierot, L. [Maison Blanche Hospital, University of Reims, Department of Radiology, Reims (France); Portefaix, C. [Maison Blanche Hospital, University of Reims, Department of Radiology, Reims (France); University of Reims, CReSTIC SIC EA3804, Reims (France)

    2012-10-15

    This study was conducted in order to evaluate the value of time-resolved contrast-enhanced magnetic resonance angiography (TR-CE-MRA) with a 3.0-T magnetic field compared to digital subtraction angiography (DSA) as the reference standard for the diagnosis of brain arteriovenous malformation (bAVM). Nineteen patients with 19 angiographically confirmed untreated bAVM were investigated with both DSA and TR-CE-MRA for the initial diagnosis. Examinations were compared by two independent readers. Interobserver agreement and intermodality agreement with respect to nidus size, arterial feeders, and venous drainage were determined using the K statistic test. Also, the quality of the TR-CE-MRA images was evaluated. Seventeen of the 19 bAVM (89.5%) detected with DSA were diagnosed with TR-CE-MRA. Interobserver agreement for TR-CE-MRA was good for nidus size, venous drainage, and arterial feeders (K = 0.75, 95% CI 0.50-1.00; K = 0.77, 95% CI 0.54-1.00; and K = 0.80, 95% CI 0.59-1.00 respectively). Intermodality agreement was good for nidus size and venous drainage (K = 0.75, 95% CI 0.49-1.00 and K = 0.77, 95% CI 0.54-1.00, respectively) and moderate for arterial feeders (K = 0.44, 95% CI 0.17-0.70). TR-CE-MRA at 3.0 T has a good sensitivity for bAVM detection and good agreement with DSA for determining nidus size and the type of venous drainage, suggesting that TR-CE-MRA is potentially a reliable tool for the diagnosis and assessment of bAVMs. However, it still suffers from low spatial resolution and vessel superposition, making differentiation of the arterial feeders of the nidus difficult at times. (orig.)

  19. Brain arteriovenous malformation diagnosis: value of time-resolved contrast-enhanced MR angiography at 3.0T compared to DSA.

    Science.gov (United States)

    Machet, A; Portefaix, C; Kadziolka, K; Robin, G; Lanoix, O; Pierot, L

    2012-10-01

    This study was conducted in order to evaluate the value of time-resolved contrast-enhanced magnetic resonance angiography (TR-CE-MRA) with a 3.0-T magnetic field compared to digital subtraction angiography (DSA) as the reference standard for the diagnosis of brain arteriovenous malformation (bAVM). Nineteen patients with 19 angiographically confirmed untreated bAVM were investigated with both DSA and TR-CE-MRA for the initial diagnosis. Examinations were compared by two independent readers. Interobserver agreement and intermodality agreement with respect to nidus size, arterial feeders, and venous drainage were determined using the K statistic test. Also, the quality of the TR-CE-MRA images was evaluated. Seventeen of the 19 bAVM (89.5%) detected with DSA were diagnosed with TR-CE-MRA. Interobserver agreement for TR-CE-MRA was good for nidus size, venous drainage, and arterial feeders (K = 0.75, 95% CI 0.50-1.00; K = 0.77, 95% CI 0.54-1.00; and K = 0.80, 95% CI 0.59-1.00 respectively). Intermodality agreement was good for nidus size and venous drainage (K = 0.75, 95% CI 0.49-1.00 and K = 0.77, 95% CI 0.54-1.00, respectively) and moderate for arterial feeders (K = 0.44, 95% CI 0.17-0.70). TR-CE-MRA at 3.0 T has a good sensitivity for bAVM detection and good agreement with DSA for determining nidus size and the type of venous drainage, suggesting that TR-CE-MRA is potentially a reliable tool for the diagnosis and assessment of bAVMs. However, it still suffers from low spatial resolution and vessel superposition, making differentiation of the arterial feeders of the nidus difficult at times.

  20. The comparison of MSCTA and 3D-DSA reconstruction imaging in diagnosis of internal carotid artery aneurysm%多层螺旋CT与三维DSA重建成像对颈内动脉瘤构型分析的比较研究

    Institute of Scientific and Technical Information of China (English)

    刘军; 王霞; 王兆华; 王浩洲; 李庆民

    2014-01-01

    Objective To investigate the diagnosis and treatment values of MSCTA and 3D-DSA reconstruction imaging in the internal carotid artery aneurysm patients. Methods A retrospective analysis of 91 patients with the clinical data and imaging data of suspected intracranial aneurysms. All patients were underwent MSCTA and 3D-DSA examination. It was mainly show the three-dimensional conformation of the internal carotid artery aneurysm, mainly study of the location and shape of the carotid artery aneurysms and the connecting mode of internal carotid aneurysm neck opening with the parent artery and the classification of the internal carotid artery aneurysm. Study the sensitivity, specificity and accuracy of MSCTA in the diagnosis of carotid artery aneurysms using 3D-DSA as standard and the consistency of MSCTA reconstruction and 3D-DSA reconstruction using Kappa analysis. Study the positive rate of MSCTA and 3D-DSA in the diagnosis of double bubble and foam type internal carotid artery aneurysm using the chi-squared test analysis. Results Using 3D-DSA reconstruction 78 patients were found with internal carotid artery aneurysms, in which the single bubble patients were 59 cases, multiple bubble patients were 19 cases, 108 internal carotid artery aneurysm were found; the internal carotid artery aneurysm can be divided into three categories:(1) Single bubble type aneurysm were 74 cases accounting for 68.52%. (2) Double bubble and foam type aneurysm were 19 cases accounting for 17.92%. (3) Shuttle type aneurysm was 1 case, accounting for 0.93%. Using MSCTA reconstruction 77 patients with internal carotid artery aneurysms were detected, the solitary cases were 58, multiple cases were 19, 106 internal carotid artery aneurysms were found, in which the single bubble type were 86 cases, double bubble and foam type were 19 cases, aortic dissecting aneurysm was 1 case. From another perspective, according to 3D-DSA reconstruction all internal carotid artery aneurysm can be divided into

  1. CTA与3D-DSA检测颅内动脉瘤的图像质量分析%Analysis of image quantity of CTA and 3D-DSA in detection of aneurysm

    Institute of Scientific and Technical Information of China (English)

    佟丹; 华树成; 王大伟; 李艳

    2008-01-01

    目的:研究CT血管造影(CTA)与三维数字减影血管造影(3D-DSA)检测颅内动脉瘤(AN)的图像质量.方法:对CTA最大密度投影(MIP)、CTA容积再现(VR)和3D-DSA VR检测的AN图像,按瘤体形态显示、瘤体三维关系、瘤体光滑度和血管显示级别评估标准进行质量评估,均按显示程度进行评分.结果;①瘤体形态显示,CTA-VR及3D-DSA VR图像质量评分均高于CTA-MIP(P0.05);②瘤体三维关系,CTA-MIP、CTA-VR及3D-DSA VR图像质量评分差异均无显著性(P>0.05);③瘤体光滑度,CTA-VR及3D-DSA VR图像质量评分均高于CTA-MIP(P0.05);④血管显示级别,3D-DSA VR图像质量评分高于CTA-MIP及CTA-VR(P0.05);⑤总体,CTA-VR及3D-DSA VR图像质量评分均高于CTA-MIP(P0.05).结论:CTA-MIP、CTA-VR和3D-DSA VR图像均可达到AN诊断要求,CTA-MIP结合CTA-VR图像观察有利于AN诊断.

  2. Assessment and treatment planning of lateral intracranial dural arteriovenous fistulas in 3 T MRI and DSA: A detailed analysis under consideration of time-resolved imaging of contrast kinetics (TRICKS) and ce-MRA sequences

    Energy Technology Data Exchange (ETDEWEB)

    Ertl, L.; Brueckmann, H.; Patzig, M.; Brem, C.; Forbrig, R.; Fesl, G. [Ludwig-Maximilians-University, Grosshadern Campus, Department of Neuroradiology, Institute of Clinical Radiology, Munich (Germany); Kunz, M. [Ludwig-Maximilians-University, Grosshadern Campus, Department of Neurosurgery, Munich (Germany)

    2016-12-15

    The current gold standard in the assessment of lateral intracranial dural arteriovenous fistulas (LDAVF) is digital subtraction angiography (DSA). However, magnetic resonance imaging (MRI) is a non-invasive emerging tool for the evaluation of such lesions. The aim of our study was to compare the DSA to our 3 T MR-imaging protocol including a highly spatial resolved (ce-MRA) and a temporal resolved (''time-resolved imaging of contrast kinetics'', TRICKS) contrast-enhanced MR angiography to evaluate if solely DSA can remain the gold-standard imaging modality for the treatment planning of LDAVF. We retrospectively reviewed matched pairs of DSA and 3 T MRI examinations of 24 patients with LDAVF (03/2008-04/2014) by the same list of relevant criteria for an endovascular LDAVF treatment planning. In particular, we determined intermodality agreement for the Cognard classification, the identifeication of arterial feeders, and the detailed assessment of each venous drainage pattern. Intermodality agreement for the Cognard classification was excellent (k = 1.0). Whereas MRI failed in identifying small arterial feeders, it was superior to the DSA in the assessment of the sinus and the venous drainage pattern. The combination of MRI and DSA is the new gold standard in LDAVF treatment planning. (orig.)

  3. 磁共振血管造影与数字减影血管造影在颅内动脉瘤术后检查中的价值比较%Comparison of MRA and DSA in examination after intracranial aneurysm surgery

    Institute of Scientific and Technical Information of China (English)

    周明利; 冯骏; 屈天荣

    2013-01-01

    Objective To compare the clinical value of digital subtraction angiography (DSA) and magnetic resonance angiography (MRA) in grading intracranial aneurysm postoperation. Methods The study recruitcd 72 patients after surgery for intracranial aneurysm. The grading of intracranial aneurysm postoperation and follow-up for three months was performed by DSA and MRA. Results Grading by DSA and TOF-MRA of intracranial aneurysm after follow-up for three months did not differ significantly ( χ2 =0. 95, P>0.05). The sensitivity of Class I intracranial aneurysm postoperation detected by MRA and DSA was 94. 3% and 97. 1% while the specificity was 91.9% and 89.2%, respectively, without significant difference (P>0.05). The grading of intracranial aneurysm postoperation and follow-up increased with the incidence of high blood pressure ( χ2=7.82, P0.05). Conclusion MRA and DSA can be used in follow-up of intracranial aneurysm surgery. The former is a non-invasive means of examination, thus deserving wide clinical application.%目的 探讨磁共振血管造影(MRA)和数字减影血管造影(DSA)两种技术对颅内动脉瘤术后分级的临床价值.方法 对72例颅内动脉瘤术后患者使用DSA和MRA技术检测颅内动脉瘤术后及随访3个月的分级情况,并对比检查结果.结果 DSA与TOF MRA对颅内动脉瘤随访3个月分级的比较差异无统计学意义(x2=0.95,P>0.05);MRA和DSA检测术后颅内动脉瘤1级的灵敏度分别为94.3%、97.1%,特异度分别为91.900、89.2%,两种方法检测差异无统计学意义(P>0.05);术后随访颅内动脉瘤分级的增加随高血压的发生率而增加(x2= 7.82,P<0.05),与高血压成正相关(r=0.47,P<0.05);MRA和DSA检测术后颅内动脉瘤患者脑血管平均分支数差异无统计学意义(P>0.05).结论 MRA与DSA均可应用于随访术后颅内动脉瘤残留瘤的分级,MRA还有无创性检查的优势,值得临床推广.

  4. Comparison between 3D-CTA with volume reconstruction and 3D-DSA in diagnosis of acute rupture of minute cerebral aneurysms%容积重建成像3D-CTA与3D-DSA在诊断急性破裂性颅内微小动脉瘤的研究

    Institute of Scientific and Technical Information of China (English)

    曾少建; 舒航; 陈光忠; 李昭杰; 詹升全; 林晓风; 周东

    2010-01-01

    Objective To evaluate the diagnostic value of three dimensional computed tomographic angiog-raphy (3D-CTA) with volume reconstruction (VR) and 3D digital subtraction angiography (3D-DSA) in diagnosis of minimal cerebral aneurysms. Method A total of 174 patients in Guangdong General Hospital, May 2007 to November 2008, of subarachnoid hemorrhage were checked upon the original imaging obtained by GE' s Light Speed Plus 64 volume spiral CT scanner at first, and then by the means of using Volume rendering (VR) three dimen-sional reconstruction and assisting the use of multiple planar reconstruction (MPR) to complete the 3D-DSA imag-ing at last. The volume rendering (VR) was assessed. Results Eleven very small cerebral aneurysms in 174 pa-tients with subarachnoid hemorrhage were diagnosed by CTA and 10 of them by 3D-DSA. Finally, all of 11 patients were confirmed by intracranial operations. The 3D-CTA (VR) clearly showed the shape and size of the intracranial aneurysms and their relationship to adjacent structures as well. There was no significant difference in the diagnosis of very small cerebral aneurysms between 3D-DSA and 3D-CTA(VR). Conclusions The 3D-CTA (VR) is a re-liable and rapid non-invasive diagnostic device for very small intracranial aneurysms. For the emergency operation,3D-CTA (VR) can provide more detailed imaging information to help the development of treatment strategy.%目的 对比研究容积重建成像三维CT血管造影与三维DSA(3D-DSA)在颅内微小动脉瘤诊疗中的临床应用价值.方法 对广东省人民医院2007年5月至2008年11月收治的174例蛛网膜下腔出血患者首先采用采用GE公司的Light Speed Plus 64排容积螺旋CT机获得原始图像,采用容积重建成像技术(VR)进行三维重建.并辅助运用多轴面重建(MPR),然后再行全脑血管造影术,并行3D-DSA成像.结果 本组174例蛛网膜下腔出血患者诊断为颅内微小动脉瘤11例,均经开颅手术证实;其中CTA诊断11例,3D

  5. Young and middle-aged and elderly patients with cerebral infarction DSA analysis of the distribution of cerebral artery stenosis%中青年与老年脑梗死患者脑动脉狭窄分布的 DSA 分析

    Institute of Scientific and Technical Information of China (English)

    曾德华

    2016-01-01

    Objective to compare the young and middle-aged and elderly patients with cerebral infarction, cerebral artery stenosis of the distribution of digital subtraction angiography (DSA) as a result, analyzing the characteristic of the distribution of cerebral artery stenosis. Methods will our hospital 100 cases of cerebral infarction patients, according to the different age groups, divided into young group of 60 cases with elderly group, 40 cases were performed DSA examination, on two groups of patients with cerebral artery disease incidence, degree of stenosis vascular stenosis, distribution and attack part feature compar-ison. Results in patients with elderly group, the procyclic stenosis of extracranial artery disease incidence is significantly higher than in areas such as the young and middle-aged group of patients, and intracranial artery, posterior circulation narrow lesions were significantly lower than in areas such as the young and middle-aged group of patients, there is statistical significance dif-ference; Two groups of patients with vascular stenosis degree is given priority to with severe stenosis or occlusion, were signifi-cantly higher than in the same group the incidence of mild, moderate stenosis, the difference was statistically significant, and the outbreak of the main parts of vertebral artery opening, the incidence of vertebral artery open two groups of patients were signifi-cantly higher than that of group of middle cerebral artery MI incidence, as well as the internal carotid artery, the difference was statistically significant. Conclusion middle-aged and young cerebral infarction patients with senile cerebral infarction there was some difference of distribution of cerebral artery stenosis, the former is common with intracranial cerebral artery lesions, the latter is given priority to with cranial outside brain artery vascular lesions, but occurs in vertebral artery opening, and the degree of stenosis were severe or occlusion.%目的:比较中

  6. Application Value Analysis of DSA Image Measurement Technique in Interventional Neuroradiology%分析介入神经放射学中DSA图像测量技术的应用价值

    Institute of Scientific and Technical Information of China (English)

    彭晓芳

    2014-01-01

    目的:探讨介入神经放射学中DSA图像测量技术的应用价值。方法:统计分析2014年1-4月收治的100例接受介入神经放射学检查或治疗的患者的临床资料。结果:100例狭窄血管患者中,95例测量结果精确,3例测量数值偏大0.1~0.3 mm,2例测量数值偏小0.1~0.2 mm,分别占总数的95%、3%、2%。误差发生的原因为图像缺乏清晰的边缘、后者参照物和被测量目标血管或病变未在同一平面上。结论:介入神经放射学中DSA图像测量技术能够有效指导其检查和治疗,介入操作医师应该对支架、保护过滤伞、弹簧圈等材料的种类、型号进行合理的选择。%To investigate the application value of DSA image measurement technique in interventional neuroradiology.Method:The clinical data of 100 patients undergoing interventional neuroradiology examination or treatment from January to April 2014 were statistically analyzed. Result:Among the 100 patients with vascular stenosis, the measurement results of 95 cases were accurate,too large 0.1-0.3 mm had 3 cases,too small 0.1-0.2 mm had 2 cases, accounting for 95%,3%and 2%of the total respectively. The reason for the error occurred were images lack sharp edges, the latter reference and target vessel or lesion to be measured which had no on the same plane.Conclusion:DSA image measurement technique in interventional neuroradiology can effectively guide the examination and treatment,physicians should choose the operation stand,umbrella protection filters,coils and other materials,type,model reasonable.

  7. DSA以及栓塞术在治疗消化道出血中的临床价值分析%A Study of Clinical Value of DSA and Embolization in the Treatment of Gastrointestinal Bleeding

    Institute of Scientific and Technical Information of China (English)

    赵年; 李春华; 李德秀; 张维珍

    2016-01-01

    目的:分析DSA检查及栓塞治疗在临床诊断和治疗急性消化道大出血的效果。方法本次研究的对象是随机选取了2014年6月-2015年6月我院收治的30例消化道出血的患者,进行腹腔动脉、肠系膜上下动脉造影,对可能出血的部位进行选择性插管造影,其中17例患者明确诊断并行栓塞治疗。结果30例患者中20例造影阳性(66.7%),10例阴性(33.3%)。18例接受了栓塞治疗,16例出血停止,一个月内无复发出血;1例栓塞后次日死亡;1例栓塞三天后复发出血,进行外科手术后痊愈。结论 DSA检查对急性消化道大出血具有较好的诊断价值,栓塞介入治疗对消化道出血止血效果优良,值得临床深入研究。%Objective To analyze the clinical effect of DSA and embolization therapy in acute gastrointestinal hemorrhage.Methods The study object, 30 cases with gastrointestinal bleeding, were randomly selected from June 2014 to June 2015 in our hospital, all of them had celiac artery and mesenteric angiography, and have selective catheterization to the possible bleeding sites, including 17 patients with definite diagnosis who had embolization. Results Twenty cases of angiography in 30 patients were positive (66.7%) and 10 (33.3%) were negative. 18 cases underwent embolization, and 16 cases stopped bleeding after embolization, with no recurrence of bleeding for a month. One case died the next day after embolization, one case had the recurrence of bleeding after three days of embolism, but recovered after surgery.Conclusion DSA examination has good diagnostic value of acute digestive tract hemorrhage. The hemostatic effect of embolization in interventional therapy for gastrointestinal bleeding is good and worthy of clinical research.

  8. Non-contrast-enhanced MR angiography in the diagnosis of Budd-Chiari syndrome (BCS) compared with digital subtraction angiography (DSA): Preliminary results.

    Science.gov (United States)

    Yang, Chun; Li, Ceng; Zeng, Mengsu; Lu, Xin; Li, Jingjing; Wang, Jiali; Sami, Muhammad Umair; Xu, Kai

    2017-02-01

    Non-CE MRA techniques (true steady-state free-precession, SSFP) have been used effectively for the selective visualization of the portal venous system and inferior vena cava. Budd-Chiari Syndrome (BCS) encompasses a number of conditions that cause the obstruction of the hepatic outflow tract from the small hepatic veins to the junction of the inferior vena cava (IVC) and right atrium. The purpose of this study was to diagnose BCS with IVC obstruction using respiratory triggered three-dimensional (3D) true SSFP with T-SLIP and compare to digital subtraction angiography (DSA). The image acquisition of 3D true SSFP scans was successfully performed in 108 patients (≧2 score). The mean and SDs of the relative SNR and CNR were 55.96±2.32 and 30.72±1.56, respectively. Intergroup agreement for the detection of the 4 types (membranous obstruction, segmental occlusion, and membranous obstruction with a hole and segmental stenosis) of BCS with IVC obstruction was excellent between the Time-SLIP and the DSA. In conclusion, Time-SLIP for the detection of IVC obstruction BCS does not require the use of contrast. This procedure can achieve a high success rate, high accuracy rate and fine image quality for the diagnosis of IVC obstruction BCS. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Acute Antibody-Mediated Rejection in Presence of MICA-DSA and Successful Renal Re-Transplant with Negative-MICA Virtual Crossmatch.

    Directory of Open Access Journals (Sweden)

    Yingzi Ming

    Full Text Available The presence of donor-specific alloantibodies (DSAs against the MICA antigen results in high risk for antibody-mediated rejection (AMR of a transplanted kidney, especially in patients receiving a re-transplant. We describe the incidence of acute C4d+ AMR in a patient who had received a first kidney transplant with a zero HLA antigen mismatch. Retrospective analysis of post-transplant T and B cell crossmatches were negative, but a high level of MICA alloantibody was detected in sera collected both before and after transplant. The DSA against the first allograft mismatched MICA*018 was in the recipient. Flow cytometry and cytotoxicity tests with five samples of freshly isolated human umbilical vein endothelial cells demonstrated the alloantibody nature of patient's MICA-DSA. Prior to the second transplant, a MICA virtual crossmatch and T and B cell crossmatches were used to identify a suitable donor. The patient received a second kidney transplant, and allograft was functioning well at one-year follow-up. Our study indicates that MICA virtual crossmatch is important in selection of a kidney donor if the recipient has been sensitized with MICA antigens.

  10. 腰椎关节突关节毗邻动脉的解剖及数字减影造影的观察%Observation of lumbar zygapophyseal joints adjacent arterials by anatomy and DSA

    Institute of Scientific and Technical Information of China (English)

    程艳; 孙兆忠; 李瑞; 房清敏; 王光林; 任佳彬

    2015-01-01

    Objective To investigate the arterials adjacent to the lumbar zygapophyseal joints by anatomy and DSA and aimed to provide a safe operation way for the lumbar back and posterolateral surgery by reducing operative hemorrhage in clinical treatment.Methods We selected 20 adult corpse lumbar departments and discovered the lumbar lateral artery and lumbar transverse process artery.Using anatomical microscope to observe the lumber transverse process artery and dosal artery of 1-4 lumber arteries from the lumbar spine 1/2-4/5.We also selected 20 patients without lumbar disease and used DSA to research their lumbar arteries and the starting,mutation or branch line of other artery sources in vivo.Results The anatomy and DSA results showed that the original location of dorsal branch usually at the anterosuperior of L1/2-4/5 foramen intervertebrale outlet area,then distributed to the outside and backside of ZJ.Anterior branch of transverse process sent out and branch into ascending and descending muscle branch.The ascending branch distributed to the below root of upper ZJ and sent out zygapophyseal branches which were distributing to the back of ZJ.The descending branch distributed to the upper root of below ZJ and sent out several muscle branches which were going into muscles in the front.And there were no statistically significant difference between left and right in the body.Conclusions The routes of arteries adjacent to ZJ and the relationship between them showed obvious regularity.Mastering its anatomical characteristics could effectively reduce the posterior surgical bleeding,make the operation easier,reduce the important tissue damage and then avoided the postoperative hematoma complications.%目的 对腰椎关节突关节(ZJ)及其毗邻血管进行解剖学及数字减影造影技术(DSA)观测,为腰椎后侧、后外侧手术入路提供解剖学依据.方法 选取20具成人尸体腰段标本,显露腰椎侧方及横突前方动脉,解剖

  11. DSA cone beam reconstruction algorithm based on backprojection weight FDK%基于FDK反投影权重的锥束DSA重建算法

    Institute of Scientific and Technical Information of China (English)

    杨宏成; 高欣; 张涛

    2013-01-01

    To solve the problem of cone beam artifacts resulting from the large cone angle in cone beam digital subtraction angiography of DSA, a novel backprojection weight reconstruction algorithm based on the frame work of FDK(BPW-FDK) was proposed. The cause of the cone beam artifacts away from the rotating track was analyzed. To solve the data deficiency in Randon space, a new backprojection weight function based on distance was designed and incorporated into the original FDK algorithm as a constraint condition for data compensation in the region far away from the rotating track to expand the reconstruction region. The reconstructing experiments were conducted on the images from simulated projections with noise or without noise and the real projections from a self-development DSA scanner. The results show that the proposed algorithm has obvious superiority over the Parker-FDK algorithm in suppression of cone beam artifacts for large cone angle projections. Compared with the Parker-FDK, the normalized mean square distance criterion and the normalized mean absolute distance criterion of the proposed algorithm are decreased by 5%.%针对锥束数字减影血管造影成像系统(DSA)锥角增大而导致锥束伪影严重的问题,提出了一种基于FDK的反投影权重锥束DSA重建算法.分析了圆扫描轨迹远端伪影的成因,针对短扫描阴影区域导致的Radon空间数据缺失,提出了一种距离变量的反投影权重函数,并将其作为约束条件引入到FDK算法中,实现扫描轨迹远端区域的数据补偿,扩大图像重建区域.应用该算法对无噪声和有噪声的模拟投影数据,及自行研发的锥束DSA的实际扫描数据分别进行了重建试验.结果表明,文中算法较FDK类算法(Parker-FDK)对大锥角投影数据可明显抑制锥角伪影,其归一化均方距离判据和归一化平均绝对距离判据比Parker-FDK均降低了5%.

  12. Quantitative analysis of artifacts in 4D DSA: the relative contributions of beam hardening and scatter to vessel dropout behind highly attenuating structures

    Science.gov (United States)

    Hermus, James; Szczykutowicz, Timothy P.; Strother, Charles M.; Mistretta, Charles

    2014-03-01

    When performing Computed Tomographic (CT) image reconstruction on digital subtraction angiography (DSA) projections, loss of vessel contrast has been observed behind highly attenuating anatomy, such as dental implants and large contrast filled aneurysms. Because this typically occurs only in a limited range of projection angles, the observed contrast time course can potentially be altered. In this work, we have developed a model for acquiring DSA projections that models both the polychromatic nature of the x-ray spectrum and the x-ray scattering interactions to investigate this problem. In our simulation framework, scatter and beam hardening contributions to vessel dropout can be analyzed separately. We constructed digital phantoms with large clearly defined regions containing iodine contrast, bone, soft issue, titanium (dental implants) or combinations of these materials. As the regions containing the materials were large and rectangular, when the phantoms were forward projected, the projections contained uniform regions of interest (ROI) and enabled accurate vessel dropout analysis. Two phantom models were used, one to model the case of a vessel behind a large contrast filled aneurysm and the other to model a vessel behind a dental implant. Cases in which both beam hardening and scatter were turned off, only scatter was turned on, only beam hardening was turned on, and both scatter and beam hardening were turned on, were simulated for both phantom models. The analysis of this data showed that the contrast degradation is primarily due to scatter. When analyzing the aneurysm case, 90.25% of the vessel contrast was lost in the polychromatic scatter image, however only 50.5% of the vessel contrast was lost in the beam hardening only image. When analyzing the teeth case, 44.2% of the vessel contrast was lost in the polychromatic scatter image and only 26.2% of the vessel contrast was lost in the beam hardening only image.

  13. 兔Vx2肝癌改良模型的建立及其DSA影像分析%Vx2 carcinoma model and its DSA imagining features in rabbits

    Institute of Scientific and Technical Information of China (English)

    曹玮; 王执民; 张洪新; 王义清; 郭卫平; 李文献; 倪代会; 梁志会; 齐连君

    2001-01-01

    AIM To establish suitable metastatic rabbit Vx2 liver tumor model for experimental study, probe into different tumor transplanted methods and analyze the DSA (digital substract angiography) imagining features of the liver tumor. METHODS 60 male New Zealand white rabbits were divided into 3 groups at random, 20 in each group. 5×107 Vx2 carcinoma cells were injected via hepatic artery, pecutaneous into liver by syringe needle in the different 2 groups (control groups); the 3rd group (retrofit group) were transplanted tumor tissue mass (about 106~108 carcinoma cells) into liver. Then we observed: ①the success rate of implanting tumor; ②the volume change of tumor by ultrasonograpy (the growth rate of tumor was calculated); ③the biological features of tumor (histopathology and electronic microscope photographs); ④the DSA imagining features of tumor. RESULTS The success rates of transplanting tumor of 3 groups were 7/20, 10/20, 19/20; the retrofit group was the highest of 3 groups (P<0.05). The tumor grew as exponential curve. Histopathology and electronic microscope photographs indicated that tumor grew in the liver tissue and infiltrated into the normal liver tissue, and that it had the similar biological features of squamous cell carcinoma transplanted in other sites of rabbits. The DSA imagining of tumor indicated that the carcinoma had liberal blood vessels. CONCLUSION A retrofit metastatic rabbit Vx2 liver carcinoma model has successfully been set up, The success rate of the method by which tumor tissue mass transplanted is obviously higher than the other two methods. This makes it possible to gain a reliable mature large tumor animal model for study.%目的 建立可供实验研究的稳定的兔Vx2移植性肝癌模型,探讨不同植瘤方式的成功率,并分析该肿瘤的DSA影像特征. 方法 新西兰白兔60只,随机分3组,每组20只. 将Vx2瘤细胞(5×107个)经肝动脉或经肝包膜分别接种于2组兔的肝

  14. Left ventricular volume determined from scintigraphy and digital angiography by a semi-automated geometric method

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    Seldin, D.W.; Esser, P.D.; Nichols, A.B.; Ratner, S.J.; Alderson, P.O.

    1983-12-01

    The utility of a semi-automatic method of measuring left ventricular (LV) volume geometrically from gated blood-pool studies and digital subtraction angiography (DSA) was investigated using computerized edge detection and spatial calibration algorithms. LAO LV volumes determined from gated blood-pool studies were compared to volumes obtained from contrast left ventriculograms in 21 patients and the applicability of this method to DSA was evaluated in 25 additional patients who also had conventional left ventriculography. There was excellent correlation between the two, both for radionuclide studies and for DSA. Computer-based geometric determinations of LV volume appear to be rapid, accurate, and less dependent on subjective operator decisions than previously reported geometric approaches.

  15. Based on DSA discusses high homocysteine hypertension and the correlation of the intracranial artery stenosis%基于DSA探讨中青年H型高血压与颅内外动脉狭窄的相关性

    Institute of Scientific and Technical Information of China (English)

    肖业; 梁辉

    2013-01-01

    Objective Based on DSA discusses high homocysteine hypertension and the correlation of the intracranial artery stenosis.Methods Through the DSA examination, Get a cerebrovascular stenosis of Young and middle-aged patients in 72 cases, the inspection 42 patients with no stenosis patients as control group. Narrow group according to the degree of stenosis and divided into light, medium and heavy. Record the patient's Risk fac-tors for age, family history, hypertension, diabetes, blood lipid and smoking, and rick in hospital after fasting ex-traction of venous blood of all the subjects, By high performance liquid chromatography determination of serum homocysteine levels. Hcy≥10 μmol/L as standard of high homocysteine levels. With HHcy as H-hypertension. Results 1. there was no statistically significant difference between normal group and narrow aboat high blood pressure and HH c y, Except H-hypertension.2. The narrow set of rate compared with statistical significance. Conclusion Confirmed that H-hypertension may be independent risk factors for outside cause of intracranial artery stenosis.%目的:基于DSA探讨高同型半胱氨酸型高血压( H 型高血压)与颅内外动脉狭窄的相关性。方法:经DSA检查,纳入有脑血管狭窄的中青年患者72例,同期检查无狭窄的中青年患者42例作为对照组,并将狭窄组根据狭窄程度分为轻、中、重度。记录患者的年龄、高血压、糖尿病、血脂和家族史及是否吸烟等危险因素。于住院后次晨空腹抽取所有受试者的静脉血,采用高效液相色谱法测定血清同型半胱氨酸(Hcy)水平。以 Hcy≥10μmol/L作为高同型半胱氨酸血症( HHcy)的标准,高血压伴 HHcy 者为 H 型高血压。结果:1.对照组与狭窄组高血压、HHcy患者比较差异无统计学意义,两组H型高血压患者比较P<0.05,差异有统计学意义。2.轻度狭窄组、中度狭窄组及重度狭窄组患

  16. DSA引导下背根节脉冲射频治疗带状疱疹后神经痛的疗效及安全性%Dosal root ganglion pulsed radiofrequency guided by DSA for postherpetic neuralgia

    Institute of Scientific and Technical Information of China (English)

    黄乔东; 宫庆娟; 薄存菊; 刘晓明; 陈金生; 卢振和; 高崇荣

    2012-01-01

    目的:观察DSA引导下背根节脉冲射频治疗带状疱疹后神经痛的疗效及其安全性.方法:60例带状疱疹后神经痛患者(VAS≥4.0),随机分为A、B两组,每组30例:A组使用加巴喷丁、阿米替林、奥施康定等药物治疗;B组在上述药物治疗的基础上.联合DSA引导下背根节脉冲射频进行治疗.观察患者射频治疗前,治疗后1、7、30、90、180 d的疼痛视觉模拟评分(VAS)、奥施康定使用量、药物副作用、治疗并发症等情况.结果:A组患者射频治疗前,治疗后1、7、30、90、180 d VAS分别为:(8.2±1.7)、(6.3±1.8)、(4.1±1.4)、(3.2 ±1.5)、(3.1 ±1.2)和(2.6 ±1.1)分.奥施康定使用量分别为:(28.8±5.5)、(35.6±8.5)、(42.3±8.9)、(18.6 ±4.3)、(10.7 ±2.4)和(8.1 ±1.6)mg.B组患者治疗前,治疗后1、7、30、90、180 d VAS分别为:(8.1 ±1.6)、(4.5 ±1.6)、(3.0 ±1.2)、(2.1±1.1)、(1.8±0.9)和(1.5±0.9)分.奥施康定使用量分别为:(29.1±5.8)、(17.6 ±5.4)、(12.4 ±3.8)、(5.1 ±1.6)、(6.0 ±1.3)和(4.2±0.9)mg,组间比较有显著差异(P<0.05),B组药物副作用减轻,无严重并发症.结论:DSA引导下背根节脉冲射频术能迅速减轻疼痛,降低镇痛药使用量并减少其相关副作用.是带状疱疹后神经痛的一种安全、有效的治疗方法.%Objective To observe the efficacy and safety of dosal root ganglion (DRG) pulsed radiofrequency for treating postherpetic neuralgia (PHN) guided by digital subtraction angiography (DSA). Methods 60 patients with PHN were randomly divided into two groups (each n= 30). Patients in Group A were treated with gabapentin, amitriptyline, and oxycodone, and patients in Group B were treated with DRG pulsed radiofrequency guided by DSA along with the same medicines used in Group A. VAS and oxycodone dosage before and 1d, 7 d, 30 d, 90 d, and 180 d after treatment, and side effects and complications during the treatment in the two groups were recorded. Results The VAS of patients in

  17. Diagnostic accuracy of colour Doppler ultrasonography, CT angiography and blood-pool-enhanced MR angiography in assessing carotid stenosis: a comparative study with DSA in 170 patients.

    Science.gov (United States)

    Anzidei, M; Napoli, A; Zaccagna, F; Di Paolo, P; Saba, L; Cavallo Marincola, B; Zini, C; Cartocci, G; Di Mare, L; Catalano, C; Passariello, R

    2012-02-01

    This study was undertaken to prospectively evaluate the diagnostic performance of colour Doppler ultrasonography (CDUS), first-pass (FP) and steady-state (SS) contrast-enhanced magnetic resonance angiography (MRA) and computed tomography angiography (CTA) of the carotid arteries using digital subtraction angiography (DSA) as the reference standard. A total of 170 patients with previous cerebrovascular events and suspected carotid artery stenoses underwent CDUS, blood-pool MRA, CTA and DSA. Accuracy, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated for CDUS, FP MRA, SS MRA and CTA. The McNemar and Wilcoxon tests and receiver operating characteristic (ROC) curve analysis were used to determine significant differences (p<0.05) between the diagnostic performances of the four modalities, and the degree of stenosis was compared using linear regression. A total of 336 carotid bifurcations were studied. The area under the curve (AUC) for degree of stenosis was: CDUS 0.85±0.02, FP MRA 0.982±0.005, SS MRA 0.994±0.002 and CTA 0.997±0.001. AUC analysis showed no statistically significant difference between CTA and MRA (p=0.0174) and a statistically significant difference between CDUS and the other techniques (p<0.001). Plaque morphology analysis showed no significant difference between CTA and SS MRA; a significant difference was seen between CTA and SS MRA versus FP MRA (p=0.04) and CDUS (p=0.038). Plaque ulceration analysis showed a statistically significant difference between MRA and CTA (0.04< p<0.046) versus CDUS (p=0.019). CTA is the most accurate technique for evaluating carotid stenoses, with a slightly better performance than MRA (97% vs. 95% for SS MRA and 92% for FP MRA) and a greater accuracy than CDUS (97% vs. 76%). Blood-pool contrast-enhanced SS sequences offer improved evaluation of degree of stenosis and plaque morphology with accuracy substantially identical to CTA.

  18. MRI与DSA影像融合联合电生理监测对脑动静脉畸形伴癫痫手术的价值%Value of MRI and 3D-DSA images fusion combined with intraoperative neuro-electrophysiological technique to surgery for intracranial arteriovenous malformation associated with epilepsy

    Institute of Scientific and Technical Information of China (English)

    孙荣辉; 徐国政; 杜浩; 宋健; 黄河; 赵曰圆; 马廉亭

    2015-01-01

    目的:探讨MRI与3D-DSA三维影像融合联合电生理监测在脑动静脉畸形伴癫痫显微手术中的应用价值。方法将1例脑动静脉畸形合并癫痫患者的MRI与3D-DSA影像数据输入神经导航进行影像融合,对病灶进行精准定位,联合术中电生理监测,完成脑动静脉畸形及致痫灶显微切除术。结果本例通过MRI与3D-DSA影像融合,精确定位显示病灶范围,术中实时导航找到主要供血动脉及引流静脉,成功切断主要供血动脉,完整切除畸形血管团,同时结合术中神经电生理技术定位脑功能区及致痫灶,术后患者无神经功能缺损,复查DSA示畸形无残留,脑电监测颅内未见异常放电。结论MRI与3D-DSA影像融合结合术中电生理监测联合应用,可以既能完全切除脑动静脉畸形病灶,又能同时清除致痫灶,保护脑重要功能区,为重要功能区脑动静脉畸形继发癫痫的治疗提供了一种安全有效的新方法。%Objective To investigate the value of MRI and 3D-DSA images fusion combined with intraoperative neuro-electrophysiological technique to the surgery for intracranial arteriovenous malformation (AVM) associated with epilepsy. Methods MRI and 3D-DSA images fusion was performed in 1 patient with epilepsy induced by AVM, in whom, AVM and epileptogenic zone were resected by neuronavigator-assisted surgery under eletroophysiological monitoring. Results The lesion was exactly located by MRI and 3D-DSA images fusion. The main arteries supplying blood to AVM and veins dainaging from AVM were found by the real-time navigation and then were ligated and cut off. AVM was totally resected. The epileptogenic zone and the functional cortex were accurately located by intraoperative eletrophysiological technique. The epileptogenic zone were successfully resected without neurological functional deficits. Conclusions MRI and 3D- DSA images fusion technology, which can clearly show

  19. Clinical observation of anesthetic effect of parecoxib- assisted propofol on the patients with cerebrovascular disease during DSA period%帕瑞昔布钠辅助异丙酚对脑血管造影静脉麻醉效果的临床观察

    Institute of Scientific and Technical Information of China (English)

    阮剑辉; 甘国胜; 张燕辉; 王庆利; 胡明; 唐京华; 李军明

    2011-01-01

    Objective To observe the anesthetic effect of parecoxib-assisted propofol on the patients with cerebrovascular disease during DSA period and its safety. Methods One hundred and twenty cerebrovascular disease patients with ASA grade Ⅰ ~ Ⅱ (age range, 17-65 years) were divided into group A and group B. In the patients of group A parecoxib sodium 40 mg were intravenously injected and in the patients of group B the equal volume of physiological saline were intravenously injected 15~20 min before the cerebral angiography. Anesthesia was maintained with a continuous infusion of propofol in the patients of both the groups during DSA period. Heart rate (HR), mean arterial pressure (MAP), SpO2 and respiratory rate (RR) were recorded before anesthesia (T1), when the femoral artery being punctured(T2), and 20 min after the beginning of the angiography (T3), and the time from stopping infusion of propofol to patients' revival (T) was observed. The propofol dose per kilogram of body weight was calculated. The Bruggmann comfort scale (BCS) after DSA and coagulation function before and after DSA were determined and compared between both the groups. Results BCS score in group B was significantly lower than in group A (P<0.05). T was significantly longer and the dose of propofol was significantly higher in group B than those in group A. There were insignificant differences in HR, MAP, SpO2 and RR at T1, T2 and T3 and coagulation function between the two groups. Conclusion Parecoxib sodium can reduce the dose of propofol, increase BCS score and does not affect the coagulation function in the patients undergoing cerebral angiography.%目的 探讨帕瑞昔布钠辅助异丙酚对脑血管造影者的麻醉效果及安全性.方法 选择120例美国麻醉医师协会分级Ⅰ~Ⅱ级的患者行脑血管造影术.这些患者分为A、B两组,每组60例,其中A组术前15~20 min静脉注射帕瑞昔布钠40 mg,B组术前静脉注射等量生理盐水.两组患者术中

  20. Comparison of contrast-enhanced MR angiography of the aortoiliac vessels using a 1.0 molar contrast agent at 1.0T with intra-arterial digital subtraction angiography; Ergebnisse der kontrastverstaerkten MR-Angiographie der aortoiliakalen Gefaesse mit einem 1-molaren Kontrastmittel bei 1,0 T; Vergleich zur i.a. DSA

    Energy Technology Data Exchange (ETDEWEB)

    Mohrs, O.K. [Klinik und Poliklinik fuer Radiologie, Johannes Gutenberg-Univ. Mainz (Germany); Cardioangiologisches Centrum Bethanien, Frankfurt/Main (Germany); Oberholzer, K.; Bernhard, S.; Kalden, P.; Thelen, M.; Kreitner, K.F. [Klinik und Poliklinik fuer Radiologie, Johannes Gutenberg-Univ. Mainz (Germany); Krummenauer, F. [Inst. fuer Med. Biometrie, Epidemiologie und Informatik, Johannes Gutenberg-Univ. Mainz (Germany); Neufang, A. [Klinik fuer Herz- und Thoraxchirurgie, Johannes Gutenberg-Univ. Mainz (Germany)

    2004-07-01

    Purpose: To evaluate the diagnostic accuracy of contrast-enhanced MR angiography (CE-MRA) using a 1.0 molar contrast agent at 1.0 T for the diagnosis of abdominal aortic aneurysms and stenoses of renal or iliac arteries in comparison to intraarterial digital subtraction angiography (DSA). Materials and Methods: A total of 19 patients with the suspicion of abdominal aortic aneurysm or stenosis of renal or iliac arteries were examined with CE-MRA at 1.0 T. Intra-arterial DAS served as reference in all cases. After test bolus tracking, 10 or 8 ml of the 1.0 molar contrast agent Gadobutrol corresponding to a dose of 0.1-0.15 mmol/kg bw were injected and imaging performed using a FLASH-3D sequence. To evaluate the interobserver-variability, the blinded images were analyzed by two radiologists. Besides the rating of overall image quality on a 4-point-scale, the images were evaluated for aneurysms and arteriosclerotic lesions with a stenosis of < 50% or > 50% or occlusion. Results: A total of 144 segments were analyzed. The mean value of the CE-MRA image quality was 3.4 on a 4-point scale. The sensitivity of CE-MRA in depicting relevant pathological findings was 96% and the specifity 99%. The positive predictive value was 96% and the negative predictive value 99%. Inter-observer variability was low with a kappa value of 0.82. Conclusion: CE-MRA using a 1.0 molar contrast agent at 1.0 Tenables an excellent diagnosis or exclusion of pathologies of the aortoiliac vessels. (orig.) [German] Ziel: Vergleich der MR-Angiographie (ce-MRA) der aortoiliakalen Gefaesse unter Verwendung eines 1-molaren, paramagnetischen Kontrastmittels bei 1,0 T zur intraarteriellen digitalen Subtraktionsangiographie (i.a. DSA). Material und Methoden: Es wurden 19 Patienten mit Verdacht auf ein infrarenales Aortenaneurysma bzw. eine Stenose der Nieren- oder Iliakalarterien untersucht. Die Messungen erfolgten bei 1,0 T unter Verwendung des 1-molaren, paramagnetischen Kontrastmittels Gadobutrol

  1. VCT 640 Layer 4 d- DSA in the Diagnosis of Liver Portal Vein Disease%640层VCT 4D-DSA对肝癌门静脉病变的诊断

    Institute of Scientific and Technical Information of China (English)

    李波; 王凯; 王金珠; 姜涛; 葛欣然; 齐宏伟; 王勇

    2016-01-01

    目的:探讨640层容积CT 4D-DSA技术评价肝癌门静脉病变异及的应用价值。方法回顾分析2012年5月—2015年5月该院确诊的80例肝癌患者640层容积CT 4D-DSA技术检查影像资料。将获得的所有容积数据导入后处理工作站,选择肝门静脉显示最佳的图像分析肝癌门静脉病变。选择80名患者三期肝脏增强扫描后所受辐射剂量进行对比。结果共有80例图像质量符合标准,存在门静脉双重供血动脉4例,80例患者中门静脉病变的36例,单纯肝动脉-门静脉瘘6例(占16.6%),单纯门静脉癌栓7例(占19.4%),肝动脉-门静脉瘘合并门静脉癌栓18例(占50%),门静脉闭塞5例(占13.8%),门静脉癌栓阻塞合并门静脉海绵样变3(占8.3%)。两种检查序列辐射剂量的有效剂量ED分别为10.539 mSv、23.159 mSv,对比结果,差异具有统计学意义P<0.05。结论640层容积CT的低辐射剂量、高清晰模仿DSA图像能应用与肝癌门静脉病变的诊断,并有助于治疗方案和预后的评价。%Objective To explore the application value of 640 slice volume 4D-DSA CT technique in the evaluation of hepatic portal vein disease variation Methods A retrospective analysis of 80 cases of hepatocellular carcinoma in our hospital from May 2012 to May 2015 was diagnosed by 640 slice volume 4D-DSA CT technique. Male 41 cases, female 39 cases, age 40~72 years old, average age (58.5±5.9) years old. All the volume data were imported into the post pro-cessing station, and the data were processed according to the time order. Selection of hepatic portal vein to display the best image analysis of hepatic portal vein lesion. The radiation doses were compared between 80 patients with stage three liver enhancement scan. Results A total of 80 patients with image quality conforms to the standard, there portal double blood supply artery in 4 cases. Including 36 patients with portal vein diseases, simple hepatic artery portal vein fistula in 6 cases (16

  2. X-ray MSCTA and DSA Imaging Analysis of Diabetic Foot%糖尿病足的X线、MSCTA和DSA影像分析

    Institute of Scientific and Technical Information of China (English)

    沈家亮; 刘毅生; 李晚君; 吴美仙; 谭志坚

    2014-01-01

    目的 探讨糖尿病足的X线、多层螺旋CT血管造影(MSCTA)和数字减影血管造影(DSA)表现,以提高其诊断能力.方法 80例采用数字化X线摄影进行足部正位、斜位照片,2 3例行双下肢动脉MSCTA检查,15例行患侧下肢动脉DSA检查.分析所见的影像征象.结果 65例骨质疏松、骨质吸收,29例骨干萎缩,8例Charcot 氏关节,5例骨质增生硬化,65例软组织病变,3例足部平片小血管钙化.38例下肢动脉粥样硬化、管腔不规则狭窄.结论 影像学检查是诊断糖尿病足的重要方法,影像学检查能很好地评价糖尿病足的骨质、血管及软组织病变,有助于糖尿病的临床治疗工作.

  3. La Lavagna Interattiva Multimediale a supporto degli studenti disabili e con DSA all’Università di Modena e Reggio Emilia

    Directory of Open Access Journals (Sweden)

    Giacomo Guaraldi

    2013-03-01

    Full Text Available Negli ultimi anni l’introduzione delle moderne tecnologie ha consentito agli studenti con disabilità di raggiungere un maggior grado di autonomia e ha favorito un mutamento nella didattica che è diventata sempre più una «didattica inclusiva», incentrata sui bisogni educativi speciali di tali soggetti e soprattutto sulle potenzialità nascoste in essi. I software per l’apprendimento, le sintesi vocali, le lavagne interattive multimediali (LIM, i netbook, i tablets, gli Ipad creano una «rete integrata» che permette, grazie a linguaggi diversi e multimodali, di accrescere l’autostima dei soggetti con disabilità e favorire la loro autonomia. La lavagna è uno strumento che stimola l’apprendimento, in quanto utilizza un linguaggio più vicino alla modalità comunicativa delle nuove generazioni, riducendo così la distanza docente e discente. Questo è tanto più importante nel caso di studenti con disabilità o con disturbo specifico dell’apprendimento: il disabile sensoriale può utilizzare la modalità comunicativa residua, il disabile motorio può «sfogliare» un testo, farselo leggere, prendere appunti, il ragazzo con DSA può usufruire della sintesi vocale per la lettura e/o per il supporto alla scrittura.

  4. DSA设备安装与导管室建设要点分析%Principles in DSA installation and catheter room construction

    Institute of Scientific and Technical Information of China (English)

    韩浙; 潘教成; 宋建华; 周水晶

    2016-01-01

    目的:利用有限的资源进行数字减影血管造影(digital substract angiology,DSA)设备机房建设和安装,使其发挥最大功效.方法:抓住DSA设备机房和导管室建设中规划选址、机房装修、设备安装、验收使用等主要环节进行机房规划、流程设计.结果:保证了机房建设和设备安装的质量,满足了不同介入手术科室的要求.结论:对机房的周全设计和设备的严谨安装,有利于延长设备的使用寿命,提高设备的使用效率.

  5. TRICKS Magnetic Resonance Angiography at 3-Tesla for Assessing Whole Lower Extremity Vascular Tree in Patients with High-Grade Critical Limb Ischemia: DSA and TASC II Guidelines Correlations

    Directory of Open Access Journals (Sweden)

    Sheung-Fat Ko

    2012-01-01

    Full Text Available The entire vascular tree of 58 lower extremities with high-grade critical limb ischemia (CLI was assessed with three-station time resolved imaging of contrast kinetics (TRICKS magnetic resonance angiography (T-MRA and correlated with digital subtraction angiography (DSA examinations and Trans-Atlantic Inter-Society Consensus II (TASC II guidelines. Kappa (κ statistics were utilized to evaluate the agreement of stenosis scores (5-point scale; 0 normal to 4 occlusion based on T-MRA and DSA. With DSA as the standard, significant stenosis instances (stenosis score ≥2 among vascular segments were compared. The κ-statistics of image quality (4-point scale; 1 nondiagnostic to 4 excellent of T-MRA and TASC II classification assessed by a radiologist and a vascular surgeon were also evaluated. Among 870 vascular segments, excellent agreement was observed between T-MRA and DSA (mean κ = 0.883 in revealing stenosis (mean stenosis score, 2.1  ±  1.3 versus 2.0  ±  1.3. T-MRA harbored overall high sensitivity (99.5%, specificity (93.6%, positive predictive value (95.4%, negative predictive value (99.6%, and accuracy (97.7% in depicting significant stenosis. Excellent interobserver agreement (mean κ = 0.818 of superb image quality (mean score = 3.5–3.6 of T-MRA and outstanding agreement of TASC II classification of aortoiliac and femoral-popliteal lesions (κ = 0.912–0.917 between two raters further verified the clinical feasibility of T-MRA for treatment planning.

  6. Preliminary experience with MRA in evaluating the degree of carotid stenosis and plaque morphology using high-resolution sequences after gadofosveset trisodium (Vasovist) administration: comparison with CTA and DSA.

    Science.gov (United States)

    Anzidei, M; Napoli, A; Geiger, D; Cavallo Marincola, B; Zini, C; Zaccagna, F; Di Paolo, P; Catalano, C; Passariello, R

    2010-06-01

    The authors performed a preliminary study with blood-pool contrast-enhanced magnetic resonance angiography (MRA) in evaluating the degree of carotid artery stenosis and plaque morphology, comparing the diagnostic performance of first-pass (FP) and steady-state (SS) acquisitions with 64-slice computed tomography angiography (CTA) and using digital subtraction angiography (DSA) as the reference standard. Twenty patients with >or=50% carotid artery stenosis at Doppler sonography underwent blood-pool contrast-enhanced MRA, CTA and DSA. Two independent radiologists evaluated MRA and CTA examinations to assess the degree of stenosis and characterise plaque morphology. Accuracy, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated for FP, SS and CTA. The McNemar and Wilcoxon tests were used to determine significant differences (p0.05). Blood-pool contrast-enhanced MRA with SS sequences allow improved diagnostic evaluation of the degree of carotid stenosis and plaque morphology compared with FP and is substantially equal to CTA and DSA.

  7. Phenol removal from wastewaters by electrochemical oxidation using boron doped diamond (BDD) and Ti/Ti{sub 0.7}Ru{sub 0.3}O{sub 2} DSA Registered-Sign electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Britto-Costa, P.H.; Ruotolo, L.A.M., E-mail: pluis@ufscar.br [Universidade Federal de Sao Carlos (UFSCAR), SP (Brazil). Dept. de Engenharia Quimica

    2012-10-15

    Industrial wastewater containing non-biodegradable organic pollutants consists of highly toxic effluents whose treatment is necessary due to environmental and economical restrictions. In order to treat these effluents, an electrochemical process using a dimensionally stable anode (DSA Registered-Sign ) and boron-doped diamond (BDD) electrode was studied. The performance of these electrodes for COD removal from aqueous phenol solution was evaluated in the absence and presence of different chloride concentrations. The results showed that DSA Registered-Sign could be successfully used to remove COD when high chloride concentration (3035 mg L{sup -1}Cl{sup -}) and mild current density are employed (50 mA cm{sup -2}). On the other hand, the presence of chloride did not have the same significant effect on the COD depletion rate using BDD; however, under mild conditions (50 mA cm{sup -2}, 0.190 m s{sup -1}), the addition of 607 mg L{sup -1} Cl{sup -} improved the COD removal by approximately 52% after 8 hours of electrolysis. The effect of current density (i) and flow velocity (v) were also studied, and it was verified that they have an important role on the process performance, especially when DSA Registered-Sign is used. (author)

  8. Oxidação eletroquímica do herbicida tebutiuron utilizando eletrodo do tipo DSA

    Directory of Open Access Journals (Sweden)

    Suellen A. Alves

    2012-01-01

    Full Text Available Tebuthiuron (TBH is a herbicide widely used in different cultures and known for its toxic effects. Electrochemical methods are promising for removing pollutants such as pesticides. This study showed the degradation of TBH using a DSA® anode operated at current densities of 50 to 200 mA cm-2. Removal presented pseudo-first order kinetics while high-pressure liquid chromatography (UV detection showed two peaks, ascribed to degradation intermediates. The maximum percentage of total organic carbon removed was 12.9%. Ion chromatography revealed that higher concentrations of nitrate and nitrite ions formed with increasing current density.

  9. Volumetric gas monitoring through a DSA laser network for the estimation of the gas emission flux by surface sources: methods and simulation results

    Science.gov (United States)

    Cuccoli, Fabrizio; Facheris, Luca; Lupo, Roberto; Berna, Tommaso

    2007-10-01

    A measurement approach for estimating the emission flux by a surface-distributed source, based on the use of IR laser measurements over optical links and atmospheric diffusion models is presented. An ad hoc disposition of the optical links close to the emission area allows to measure gas concentration over a closed surface corresponding to an air volume that covers the whole emission area. The real time concentration measurements over this closed surface, associated to suitable diffusion models, allow us to estimate the emission flux of the area under exam. The diffusion model to be applied strictly depends on the current atmospheric conditions, therefore it requires the knowledge of the main atmospheric parameters. In this paper we present some simulation results about a system for the surface flux monitoring assuming the faces of a parallelepiped the surfaces interested by laser measurements. The closed surface is therefore defined by 5 of its sides, while the 6th is the emission surface. We discuss some estimation results using diffusion models where the air diffusion and transportation phenomena are due mainly to the wind strength.

  10. Use of sequential infiltration synthesis to improve the pattern transfer of PS-b-PLA DSA (Conference Presentation)

    Science.gov (United States)

    Evangelio Araujo, Laura; Fernández-Regúlez, Marta; Chevalier, Xavier; Nicolet, Célia; Cayrefourcq, Ian; Navarro, Christophe; Fleury, Guillaume; Pérez-Murano, Francesc

    2017-03-01

    Directed self-assembly of block copolymers is considered one of the candidates to fulfill the requirements of the next technological nodes [1,2]. Polymer domains are aligned by using a chemical and/or a topographical pre-pattern in which preferential surfaces to one of the two blocks or neutral wetting areas are created. In particular, polystyrene-block-polymetylmethacrylate (PS-b-PMMA) has been extensively studied during the last years showing strong capabilities to define periodic nanostructures. However, the relatively low Flory-Huggins parameter and, the resulting low segregation strength of PS-b-PMMA systems, limit their achievable resolution to around 11 nm [3]. The application of block copolymer on sub-10 nm technologies requires the development of the new block copolymer generation known as high- block copolymers. Additionally, an important requirement for their integration on the lithography roadmap is the capability of selectively remove one of the two blocks. The etch contrast between the two domains is typically low due to their organic chemistry. In this sense, selective sequential infiltration synthesis by ALD into one of the blocks can be used in order to incorporate an inorganic material. The formed organic/inorganic blend sustains better the plasma etching to remove the non-infiltrated organic block. In this contribution, we show the use of high- polystyrene-b-polylactide acid (PS-b-PLA) lamellar block copolymer for line/space applications. PS-b-PLA has a larger Flory-Huggins parameter (=0.218 at room temperature[4]) compared with PS-b-PMMA, allowing the size reduction of the self-assembled domains. The method to control the orientation of the polymer domains is similar to the one typically used for PS-b-PMMA. Chemical contrast and the subsequent alignment of the polymer domains are achieved by the definition of a chemical pre-pattern on a random copolymer PS-r-PMMA (48% of PS) (figure 1). The polymer brush is grafted on the substrate and then

  11. Doppler-shift attenuation method lifetime measurements in {sup 115}Sb and {sup 117}Sb

    Energy Technology Data Exchange (ETDEWEB)

    Bucurescu, D.; Cata-Danil, I.; Ilas, G.; Ivascu, M.; Stroe, L.; Ur, C.A. [Institute of Atomic Physics, P.O. Box MG-6, Bucharest 76900 (Romania)

    1995-08-01

    The lifetimes of several low-lying excited levels in {sup 115}Sb and {sup 117}Sb have been measured by using the DSA method in the {sup 115,117}Sn({ital p},{ital n}{gamma}){sup 115,117}Sb reactions, respectively. The structure of these nuclei is discussed in the frame of the interacting boson-fermion model.

  12. 仿真三维DSA血管内镜成像在颅内动脉狭窄诊治中的作用%Effect of virtual vascular 3D-DSA endoscopic imaging in the diagnosis and treatment of intracranial arterial stenosis

    Institute of Scientific and Technical Information of China (English)

    段鸿洲; 莫大鹏; 张扬; 伊志强; 李良; 张家涌; 鲍圣德

    2011-01-01

    目的:探讨仿真三维DSA血管内镜成像在颅内动脉狭窄诊治中的价值.方法 回顾性分析76例颅内动脉狭窄患者的三维DSA血管内镜成像资料,其中11例患者行颅内动脉支架置入术,并应用三维血管内镜随访其支架置入后血管腔内情况.三维旋转数字图像由脑血管造影机球管和影像增强器的同步2次240°旋转获得,应用Volume Viewer软件对原始三维图像进行重建,固定密度值并选取感兴趣区,用Navigator软件进行三维血管内镜成像,观察血管腔内的结构情况.结果 ①76例患者三维DSA血管内镜成像清晰,共114处血管狭窄,内膜形态光滑87处,不光滑27处;斑块偏心81处,基本不偏心33处.②对11例患者行颅内动脉支架置入术,技术成功率100%,术后残余狭窄率均<30%,预后良好.③三维DSA血管内镜随访支架置入的患者11例,术后6个月时7例患者的支架被内膜覆盖完全、光滑;术后12个月时10例患者的支架被内膜覆盖完全;术后18个月时1例患者的支架仍未被内膜完全覆盖.结论 仿真三维DSA血管内镜成像是一种安全有效的评估颅内动脉管腔结构的方法,并可用于指导支架置入后抗血小板聚集药物的个体化治疗.%Objective To investigate the value of virtual vascular 3D-DSA endoscopic imaging in the diagnosis and treatment of intracranial arterial stenosis. Methods The data of 3D-DSA endoscopic imaging in 76 patients with intracranial arterial stenosis were analyzed retrospectively. Eleven of the patients underwent intracranial artery stenting and a 3D vascular endoscopy was used to follow up its endovascular conditions after stenting. The 3D rotate pictures were obtained by the twice synchronized rotation of bulb and an image enhancer for 240° rotation. The original 3D images were reconstructed using the Volume Viewer software. The density value was fixed and the region of interest was selected. Navigator software was used for 3D

  13. DSA在颈动脉体瘤术前诊断中的价值%Diagnostic value of DSA in preoperative carotid body tumor

    Institute of Scientific and Technical Information of China (English)

    任勇军; 杨林; 翟昭华; 缪南东; 邓进

    2010-01-01

    目的 回顾性分析颈动脉体瘤(CBT)的数字减影血管造影(DSA)表现,探讨DSA在CBT术前诊断中的价值.方法 收集并分析11例(12个)CBT患者的临床资料和DSA表现.结果 11例CBT临床均表现为颈部无痛性肿块,肿块呈椭圆形、圆形,质较硬,实性,边界清楚,无压痛,其中颈部闻及血管杂音2例;肿物可前后推动而不能上下移动.DSA显示所有患侧颈动脉分叉夹角增大,颈内外动脉移位;所有CBT肿瘤血供丰富,肿瘤染色明显,瘤体与血管的关系清晰,主要供血动脉起源于颈外动脉.DSA显示瘤体位于颈总动脉分叉内3个,9个瘤体呈偏心性生长并包绕颈内动脉或颈总动脉分叉.瘤体直径3.0~9.0 cm,平均约(4.5±1.5)cm.DSA显示右侧6例,左侧4例,双侧1例.肿瘤定性、定位以及与邻近血管的关系与外科手术、病理检查结果相符.结论 大多数CBT临床表现不典型,易于误诊,但具有特殊的DSA表现.DSA能清晰显示瘤体与颈部血管关系,为外科手术或栓塞治疗提供了可靠的依据.DSA诊断CBT准确率100%.

  14. Clinical Value of MSCT Neuro-DSA in the Diagnosis of Carotid Artery Stenosis%多层螺旋CT时间减影血管造影在颈部动脉狭窄诊断中的应用

    Institute of Scientific and Technical Information of China (English)

    冯爱平; 蒲艳军; 屈先凤; 朱力; 郭笑寒

    2015-01-01

    目的 探讨多层螺旋CT时间减影血管造影(Neuro-DSA)在颈动脉狭窄诊断中的应用价值.方法 回顾性分析30例疑似颈动脉病变患者的Neuro-DSA图像,以颈动脉数字减影血管造影(DSA)结果作为对照,分析并比较两种方法诊断血管狭窄程度的一致性.结果 ①Neuro-DSA与DSA对30例患者180支血管的检出结果比较,差异无统计学意义(x2 =1.11,P>0.05).②以DSA为金标准,Neuro-DSA诊断血管无狭窄、轻度、中度、重度狭窄和闭塞的准确度分别为94.4%、94.4%、92.2%、97.8%和100.0%.Neuro-DSA与DSA诊断一致性的Kappa值为0.65(P <0.01).③Neuro-DSA有效剂量(2.58±0.27) mSv低于DSA(330.00±20.00) mSv(P <0.01).结论 Neuro-DSA能较清楚、直观地显示颈动脉狭窄位置、程度,尤其在诊断血管重度狭窄和闭塞方面具一定优势.

  15. 颈内动脉动脉瘤3D-DSA重建成像的构型分析%Configuration analysis of 3D-DSA reconstruction imagings of internal carotid artery (ICA)aneurysm

    Institute of Scientific and Technical Information of China (English)

    刘军; 王霞; 王浩洲; 王琳; 李吉贞; 张明然; 王莲

    2013-01-01

    目的 分析颈内动脉(ICA)动脉瘤在3D-DSA中的三维构型特点,探讨其指导临床的意义.方法 回顾性总结77例ICA动脉瘤患者3D-DSA的影像资料,对77例107个动脉瘤应用Syngo Inspace软件任务卡进行重建成像,显示其三维容积及三维形态结构,研究动脉瘤形态与ICA及其分支动脉开口的结构关系.结果 按ICA Bouthillier分段,动脉瘤在C4~C5段4个,C6~C7段(床突上段)103个.动脉瘤以类圆形鼓泡状形态自ICA凸起,其形态可分为单泡型74个(69.2%)、双泡型21个(19.6%)、多泡型12个(11.2%),双泡型及多泡型动脉瘤以圆泡连体的方式沿颈动脉轴线排列,不会横向排列.其中单泡型动脉瘤又分为单泡漏斗型、单泡水泡型、单泡窄颈型及单泡宽颈型.根据动脉瘤瘤颈开口与ICA及其分支动脉开口的关系,又可将动脉瘤分为分支无关型、分支相关型和分支泡上发出型,分别有51个、37个和19个.结论 根据3D-DSA可了解ICA动脉瘤的部位、形态结构,尤其是动脉瘤开口与ICA及其分支动脉开口的结构关系,对临床选择治疗方法,以及对治疗过程中容易产生的问题、术后疗效的判断都具有重要的指导意义.%Objective To study the three-dimensional configuration characteristic of internal carotid artery (ICA) aneurysms in 3D-DSA reconstruction imaging,and to discusses its guiding meaning for clinical teeatment of ICA aneurysm.Methods Retrospective analysis of 77 patients with ICA aneurysms.There were 107 aneurysms in 77 cases.Syngo Inspace software was used to reconstruct imaging to display three-dimensional volume and structure of the carotid artery aneurysm,and to study the space structure relationship of aneurysm with the ICA and branch artery.Results According to the Bouthillier segmentation of ICA.There were 4 aneurysms occurred in C4 ~ C5,and 103 in C6 ~ C7 (supraclinoidal segment).The aneurysms protrude from ICA with a series of circular bubble

  16. Application of rotational DSA dual volume technology in the displaying of intracranial artery stent and its effective analysis%颅内动脉支架的旋转DSA双容积显示方法及效果分析

    Institute of Scientific and Technical Information of China (English)

    沈正林; 胡克琦; 闻宏斌; 李秀荣; 常丽英

    2016-01-01

    合显示技术能较好地表现血管内的支架情况。%Objective To investigate the implementation and application of rotational DSA dual volume technology in displaying the intracranial artery stent.Methods Firstly,the “stent opacity”single volume technology was used to display 5 types of stent which were released in 7 cases of pure intracranial artery stenting and 12 cases of stent-assisted aneurysm embolization.Then we applied “vessel translucent”and “vessel opacity”single volume technology to display corresponding vessel segments.Finally,by coalescing the single volume imaging of stent and vessel,the “vessel opacity + stent opacity”dual volume image and “vessel translucent+ stent opacity”dual volume image were performed.We compared the effects of two kinds of dual volume imaging and assessed the imaging characteristics and influencing factors of each method.Results (1)On the “stent opacity”single volume display mode,in 7 cases of pure intracranial artery stenting,the display effect of two Pipeline stents and three Apollo stents belongs to level 1,the display effect of two Enterprise stents belongs to level 2;In 12 cases of stent-assisted aneurysm embolization,in the stent segments which weren’t influenced by artifacts,the display effect of two LEVIS stents belongs to level 1,the display effects of 5 Enterprise stents and 2 Solitaire AB stents belongs to level 2;While in the stent segments which were influenced by the artifact of spring coil and bone,the display effect significantly reduced, three pieces of Enterprise stents were even unable to identify.(2)On the “vessel opacity”single volume display mode,1 9 cases of vessel segment at the stent completed opacity display.The surface structure of vessel was very clear,but the structure under the surface was completely being covered.On the “vessel translucent”single volume display mode,the surface structure of 19 cases of vessel segment at the stent displayed clear at the tangential position.The vessel

  17. Synthesis of tetramethyl ammonium hydroxide by cell diaphragm electrolytic method

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Under the conditions of tetramethyl ammonia chloride (TMAC) used as starting material, Ti-based Dimensionally Stable Anode (DSA), stainless steel used as cathode and Nafion 900 cation membrane as cell diaphragm, this paper studies the synthesis of tetramethyl ammonium hydroxide (TMAH) by cell diaphragm electrolytic method, examining not only the effects of current density, concentration of starting material and cell temperature, on the product purity and current efficiency, but also the effects of electrolyte circulation rate on the service life of Ti-based DSA.The experiment puts forward an optimum processing condition, and experimental findings show that preparing TMAH by using this technique can obtain a current efficiency 74.7 % and get product with a purity greater than 99.9%.

  18. Extension of moment projection method to the fragmentation process

    Science.gov (United States)

    Wu, Shaohua; Yapp, Edward K. Y.; Akroyd, Jethro; Mosbach, Sebastian; Xu, Rong; Yang, Wenming; Kraft, Markus

    2017-04-01

    The method of moments is a simple but efficient method of solving the population balance equation which describes particle dynamics. Recently, the moment projection method (MPM) was proposed and validated for particle inception, coagulation, growth and, more importantly, shrinkage; here the method is extended to include the fragmentation process. The performance of MPM is tested for 13 different test cases for different fragmentation kernels, fragment distribution functions and initial conditions. Comparisons are made with the quadrature method of moments (QMOM), hybrid method of moments (HMOM) and a high-precision stochastic solution calculated using the established direct simulation algorithm (DSA) and advantages of MPM are drawn.

  19. Extension of moment projection method to the fragmentation process

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Shaohua [Department of Mechanical Engineering, National University of Singapore, Engineering Block EA, Engineering Drive 1, 117576 (Singapore); Yapp, Edward K.Y.; Akroyd, Jethro; Mosbach, Sebastian [Department of Chemical Engineering and Biotechnology, University of Cambridge, New Museums Site, Pembroke Street, Cambridge, CB2 3RA (United Kingdom); Xu, Rong [School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive, 637459 (Singapore); Yang, Wenming [Department of Mechanical Engineering, National University of Singapore, Engineering Block EA, Engineering Drive 1, 117576 (Singapore); Kraft, Markus, E-mail: mk306@cam.ac.uk [Department of Chemical Engineering and Biotechnology, University of Cambridge, New Museums Site, Pembroke Street, Cambridge, CB2 3RA (United Kingdom); School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive, 637459 (Singapore)

    2017-04-15

    The method of moments is a simple but efficient method of solving the population balance equation which describes particle dynamics. Recently, the moment projection method (MPM) was proposed and validated for particle inception, coagulation, growth and, more importantly, shrinkage; here the method is extended to include the fragmentation process. The performance of MPM is tested for 13 different test cases for different fragmentation kernels, fragment distribution functions and initial conditions. Comparisons are made with the quadrature method of moments (QMOM), hybrid method of moments (HMOM) and a high-precision stochastic solution calculated using the established direct simulation algorithm (DSA) and advantages of MPM are drawn.

  20. Comparison of effects of transcranial Doppler sonography and transcranial color Doppler ultrasonography on diagnosis of Moyamoya disease with that of DSA%经颅多普勒及彩色经颅多普勒超声与DSA对烟雾病诊断的比较分析

    Institute of Scientific and Technical Information of China (English)

    张小征; 莫雪红; 华莎; 杨铭; 陈刚; 马廉亭

    2011-01-01

    Objectives To summarize the experiences in diagnosing Moyamoya disease by transcranial color Doppler ultrasonography (TCCD) and to evaluate the clinical value of TCCD to noninvasive diagnosis of Moyamoya disease. Methods Of 137 patients with Moyamoa disease diagnosed as by DSA, 24 received transcranial Doppler (TCD) examination and 113 did TCCD. The outcomes of TCD and TCCD examination were compared to that DSA which was performed in all the patients. Results The diagnosis of Moyamoya disease was definitely made by TCD in 22, Moyamoya disease was highly suspected in 1 and Moyamoya disease was not detected in 1 of the 24 patients with Moyamoya disease receiving TCD. The positive detected rate of Moyamoya disease by TCD was 95.8%. The diagnosis of Moyamoya disease was definitely made by TCCD in 102, Moyamoya disease was highly suspected in 8 and TCCD examination failed of success in 3 because there were not bone windows through which the sound passed. Conclusions The vessels in the brain bases and changes in their hemodynamics can dynamically be observed in real time by TCD and TCCD. TCCD is more helpful to estimating the occlusion and light stenosis of the intracranial vessels and it is of higher value to diagnosing Moyamoya disease than TCD because it is more sensitive to the blood flow in the stenosed vessels. TCD and TCCD, which are noninvasive methods, should be firstly selected for diagnosing and following up in the patients with Moyamoya disease.%目的 探讨经颅多普勒(TCD)及彩色经颅多普勒超声(TCCD)对烟雾病诊断的临床应用价值.方法 采用TCD及TCCD探测137例烟雾病患者颅内血管血流动力学的改变,并与其DSA结果比较分析.结果 TCD探测24例,明确诊断22例,高度怀疑1例,阴性者1例,与DSA比较诊断符合率为96%.TCCD探测113例,明确诊断102例,高度怀疑8例,因无透声窗检测失败3例,与DSA比较诊断符合率为97%.结论 TCD及TCCD均能实时动态地观察颅底血管血流动力

  1. Effect and Therapeutic Outcome of Biplane DSA and its C-arm Cone-beam CT Imaging in the Treatment of Ozone Injection Therapy for Lumbar Disc Herniation%双平板DSA引导下经皮穿刺臭氧消融术治疗腰椎间盘突出症的临床疗效观察(附37例报告)

    Institute of Scientific and Technical Information of China (English)

    杨超; 倪才方; 陈珑; 李智; 张帅

    2013-01-01

    Objective To observe the effect of biplane DSA and its C-arm cone-beam CT imaging in the treatment of ozone injection therapy for the lumbar disc herniation and to evaluate its therapeutic outcome. Meth-ods Retrospective analysis of 37 cases with lumbocrural pain or numbness patients, the mean age is (49.38±13.05) years, forty-four intervertebral discs were treated, CT or MRI conifrmed lumbar disc herniation. We perfomed ozone injection therapy under biplane DSA machine, during the procedure, 4 to 25 mL (mean 13.82±3.62 mL) ozone was injected in each lesion disc, and 0~15 mL was injected around the nerve root, then a total of 5mL tri-amcinolone acetonide was also injected in the disc and paraspinal. Then we observe the changes of lumbocrural pain pre-procedure, and 1 week, 1 month, 3 months, 6 months, 1 year after it. Besides, the intraoperative and post-operative complications were also recorded. Results In 37 patients, 34 cases got VAS score decrease in the lumbo-crural pain, and the pain relief time lasted more than 1 year. The total efifciency of modiifed Macnab evaluation is 91.89%, 3 cases with no obvious pain relief, including 1 case of intervertebral disc infection. Conclusion By the use of biplane DSA and its C-arm cone-beam CT imaging, ozone injection therapy for the lumbar disc herniation brings less trauma, less complications, and better analgesic effect.%目的:观察双平板DSA及其类CT功能在经皮穿刺臭氧消融术治疗腰椎间盘突出症中的应用及临床疗效。方法回顾性分析37例腰腿疼痛或麻木患者,平均年龄(49.38±13.05)岁,共44个病变椎间盘,经CT或MRI证实为腰椎间盘突出症,在双平板DSA设备透视引导下行经皮穿刺臭氧消融术,术中每个椎间盘内注射臭氧4~25 mL(平均13.82±3.62 mL),盘外神经根周围注射臭氧0~15 mL(平均7.73±2.87 mL),并于盘内外注射曲安奈德水针共5 mL。观察术前及术后1周、1个月、3个月、6

  2. Time-video density curve of indirect portal vein DSA:its value in assessing the liver function condition%间接性门静脉DSA的时间-视频密度曲线对肝功能状态的评估价值

    Institute of Scientific and Technical Information of China (English)

    吴廷创

    2011-01-01

    目的 初步探讨肝门静脉DSA的时间-视频密度曲线(TVDC)参数对肝功能状态评估的价值.方法 收集2007年7月-2008年10月进行介入诊疗的肝癌(HCC)患者42例,其中男35例,女7例,平均年龄56岁(28~76岁),肿块平均10.38 cm(5.5~15.5 cm).按肝功能Child-Pugh分级将患者分成A组(24例)、B组(11例)和C组(7例).其中35例经脾动脉插管、7例经肠系膜上动脉插管行间接性肝门静脉造影.利用DSA图像处理软件选定兴趣区(ROI),生成TVDC,取得并对比各参数值(PV、KmaxU、KmaxD、PT).结果 随肝功能分级增加,PV、KmaxU、KmaxD逐渐降低,PT逐渐增加,但三组间PV差异无统计学意义(P > 0.05),A组与B组、A组与C组间的KmaxU差异有统计学意义(P < 0.01),但在B组与C组间差异无统计学意义(P > 0.05).A组与B组及C组间的KmaxD差异有统计学意义(P < 0.01),B组与C组间差异亦有统计学意义(0.01 < P < 0.05).结论 肝门静脉DSA的TVDC参数可以反映肝功能的变化.%Objective To preliminary evaluate the various parameters of the time-video density curve ( TVDC ) obtained by indirect portal vein DSA in assessing the liver function condition. Methods A total of 42 patients with hepatocellular carcinoma (35 males and 7 females with a mean age of 56 years),encountered in author's hospital during the period from July 2007 to Oct. 2008 , were enrolled in this study.Based on the Child-Pugh hepatic function classification, the patients were divided into group A (n = 24), group B (n = 11 ) and group C (n =7 ). Indirect portal vein angiography was performed in all patients via splenic artery ( n = 35 ) or superior mesenteric artery ( n = 7 ) catheterization. Region of interest ( ROI ) was selected with the help of DSA image processing software, and the TVDC was obtained. Various parameter values, including PV, KmaxU , KmaxD and PT, were determined. A paired t'-test was used for statistical analysis. The results were analyzed and

  3. Determination of Dopamine in the Presence of Ascorbic Acid on the IrO2-Ta2O5 Type DSA Electrode

    Institute of Scientific and Technical Information of China (English)

    Yang LIU; Zhi Ying LI; Jing Hong LI

    2005-01-01

    . IrO2/Ta2O5 (70%: 30%, molar ratio) electrodes (ITEs) were prepared by the thermal decomposition method. Typical "mud-cracked" surface and surface enrichment of Ta were observed. The determination of dopamine (DA) was carried out in the presence of ascorbic acid (AA). The detection limit of DA was 5×10-5 mol/L without the interference of AA.

  4. 双源 CT 双能量 CTA 与常规 CTA-DSA 技术在头颈部血管成像的效果比较

    Institute of Scientific and Technical Information of China (English)

    唐永洪; 贾玉柱; 呙登俊

    2014-01-01

    目的:探讨双源CT双能量CTA与常规CTA-DSA 技术在头颈部血管成像中的应用效果。方法将48例行双源CT头颅CTA的临床怀疑头颈部血管病变患者按影像号码单,双号平均分为DE-CTA组和Neuro-DSA组。比较两组血管图像质量、辐射剂量。结果 DE-CTA组与Neuro-DSA组血管颅外段,颈动脉管段图像质量差异无统计学意义(P>0.05),但虹吸段颅底部去骨的效果Neuro-DSA优于DE-CTA (P<0.05);DE-CTA组辐射剂量为(20.56±0.05)mGy,低于Neuro-DSA组的(25.64±0.08)mGy(t=-0.036,P<0.05)。结论头颈部血管DE-CTA与Neuro-DSA成像对比DE-CTA辐射小,成像质量效果较好,但虹吸段颅底去骨效果欠佳,技术亟需改进。

  5. Evaluate the ability of CTA to help detect and quantify intracranial stenosis and occlusion compared with DSA%颅内动脉粥样硬化性狭窄CTA与DSA检查的对比分析

    Institute of Scientific and Technical Information of China (English)

    陈晓东

    2010-01-01

    目的:探讨CT血管成像(CTA)与数字减影血管造影(DSA)在诊断颅内动脉粥样硬化狭窄中的应用价值.方法:选取缺血性脑血管病患者42例,先行CTA检查,按照狭窄程度的不同,将病变血管分为基本正常(0%~9%),轻度狭窄(10%~49%),中度狭窄(30%~69%)和重度狭窄(70%~100%).其后根据DSA检查作为标准,比较CTA对脑血管狭窄程度的敏感性和特异性.结果:42例患者中CTA发现狭窄血管249条.将CTA诊断结果与DAS结果比较,显示CTA在诊断基本正常、轻度、中度及重度血管狭窄的敏感性和特异性分别为98%和100%、96%和96%、94%和98%、100%和100%.结论:CTA对诊断脑内动脉狭窄具有较高的敏感性和特异性,可作为颅内动脉粥样硬化性狭窄筛选的常规检查方法.

  6. DSA介入诊疗旁散射分布的快速蒙特卡罗模拟研究%Monte Carlo simulation based side-scatter distribution of DSA interventional diagnosis and therapy

    Institute of Scientific and Technical Information of China (English)

    赵旭东; 刘鸿祥

    2016-01-01

    目的:根据X线散射平滑特性,提出一种面向数字减影血管造影(digital substract angiology,DSA)介入诊疗旁散射分布的快速蒙特卡罗(Monte Carlo,MC)模拟.方法:基于MC模拟算法进行X线光子模拟,并且针对旁散射模拟效率过低导致信号噪声过大的问题,提出一种基于泊松统计分布的投影平滑去噪方法,从而快速准确地计算出旁散射的信号图像.结果:在仿真实验中,当β值为0.020时,噪声平滑抑制后的信噪比相对于噪声抑制前提升了6.8 dB,同时均方根误差相比去噪前下降了27.18.在真实机器数据实验中,散射强度强的区域,当B值为0.02时,均方根误差比噪声平滑抑制前平均提升了5.20,旁散射模拟的时间从270 min缩短到3 min.结论:该方法有较好的去噪效果,同时也能保留有用信息,能够实现快速准确地模拟旁散射图像.

  7. method

    Directory of Open Access Journals (Sweden)

    L. M. Kimball

    2002-01-01

    Full Text Available This paper presents an interior point algorithm to solve the multiperiod hydrothermal economic dispatch (HTED. The multiperiod HTED is a large scale nonlinear programming problem. Various optimization methods have been applied to the multiperiod HTED, but most neglect important network characteristics or require decomposition into thermal and hydro subproblems. The algorithm described here exploits the special bordered block diagonal structure and sparsity of the Newton system for the first order necessary conditions to result in a fast efficient algorithm that can account for all network aspects. Applying this new algorithm challenges a conventional method for the use of available hydro resources known as the peak shaving heuristic.

  8. Method

    Directory of Open Access Journals (Sweden)

    Xixin Wang

    2012-01-01

    Full Text Available ZrO2 nanotube arrays were prepared by anodization method in aqueous electrolyte containing (NH42SO4 and NH4F. The morphology and structure of nanotube arrays were characterized through scanning electron microscope, X-ray diffraction, and infrared spectra analysis. The zirconia nanotube arrays were used as catalyst in esterification reaction. The effects of calcination temperature and electrolyte concentration on catalytic esterification activity have been investigated in detail. Experiments indicate that nanotube arrays have highest catalytic activity when the concentration of (NH42SO4 is 1 mol/L, the concentration of NH4F is 1 wt%, and the calcination temperature is 400°C. Esterification reaction yield of as much as 97% could be obtained under optimal conditions.

  9. Method

    Directory of Open Access Journals (Sweden)

    Andrey Gnatov

    2015-01-01

    Full Text Available Recently repair and recovery vehicle body operations become more and more popular. A special place here is taken by equipment that provides performance of given repair operations. The most interesting things are methods for recovery of car body panels that allow the straightening without disassembling of car body panels and damaging of existing protective coating. Now, there are several technologies for repair and recovery of car body panels without their disassembly and dismantling. The most perspective is magnetic-pulse technology of external noncontact straightening. Basics of magnetic-pulse attraction, both ferromagnetic and nonferromagnetic thin-walled sheet metal, are explored. Inductor system calculation models of magnetic-pulse straightening tools are presented. Final analytical expressions for excited efforts calculation in the tools under consideration are introduced. According to the obtained analytical expressions, numerical evaluations of excited forces were executed. The volumetric epures of the attractive force radial distributions for different types of inductors were built. The practical testing of magnetic-pulse straightening with research tools is given. Using the results of the calculations we can create effective tools for an external magnetic-pulse straightening of car body panels.

  10. Assessment of New Calculation Method for Toxicological Sums-of-Fractions for Hanford Tank Farm Wastes

    Energy Technology Data Exchange (ETDEWEB)

    Mahoney, Lenna A.

    2006-10-18

    The toxicological source terms used for potential accident assessment in the Hanford Tank Farms DSA are based on toxicological sums-of-fractions (SOFs) that were calculated based on the Best Basis Inventory (BBI) from May 2002, using a method that depended on thermodynamic equilibrium calculations of the compositions of liquid and solid phases. The present report describes a simplified SOF-calculation method that is to be used in future toxicological updates and assessments and compares its results (for the 2002 BBI) to those of the old method.

  11. Comparison of RF spectrum prediction methods for dynamic spectrum access

    Science.gov (United States)

    Kovarskiy, Jacob A.; Martone, Anthony F.; Gallagher, Kyle A.; Sherbondy, Kelly D.; Narayanan, Ram M.

    2017-05-01

    Dynamic spectrum access (DSA) refers to the adaptive utilization of today's busy electromagnetic spectrum. Cognitive radio/radar technologies require DSA to intelligently transmit and receive information in changing environments. Predicting radio frequency (RF) activity reduces sensing time and energy consumption for identifying usable spectrum. Typical spectrum prediction methods involve modeling spectral statistics with Hidden Markov Models (HMM) or various neural network structures. HMMs describe the time-varying state probabilities of Markov processes as a dynamic Bayesian network. Neural Networks model biological brain neuron connections to perform a wide range of complex and often non-linear computations. This work compares HMM, Multilayer Perceptron (MLP), and Recurrent Neural Network (RNN) algorithms and their ability to perform RF channel state prediction. Monte Carlo simulations on both measured and simulated spectrum data evaluate the performance of these algorithms. Generalizing spectrum occupancy as an alternating renewal process allows Poisson random variables to generate simulated data while energy detection determines the occupancy state of measured RF spectrum data for testing. The results suggest that neural networks achieve better prediction accuracy and prove more adaptable to changing spectral statistics than HMMs given sufficient training data.

  12. A moment projection method for population balance dynamics with a shrinkage term

    Science.gov (United States)

    Wu, Shaohua; Yapp, Edward K. Y.; Akroyd, Jethro; Mosbach, Sebastian; Xu, Rong; Yang, Wenming; Kraft, Markus

    2017-02-01

    A new method of moments for solving the population balance equation is developed and presented. The moment projection method (MPM) is numerically simple and easy to implement and attempts to address the challenge of particle shrinkage due to processes such as oxidation, evaporation or dissolution. It directly solves the moment transport equation for the moments and tracks the number of the smallest particles using the algorithm by Blumstein and Wheeler (1973) [41]. The performance of the new method is measured against the method of moments (MOM) and the hybrid method of moments (HMOM). The results suggest that MPM performs much better than MOM and HMOM where shrinkage is dominant. The new method predicts mean quantities which are almost as accurate as a high-precision stochastic method calculated using the established direct simulation algorithm (DSA).

  13. A moment projection method for population balance dynamics with a shrinkage term

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Shaohua [Department of Mechanical Engineering, National University of Singapore, Engineering Block EA, Engineering Drive 1, 117576 (Singapore); Yapp, Edward K.Y.; Akroyd, Jethro; Mosbach, Sebastian [Department of Chemical Engineering and Biotechnology, University of Cambridge, New Museums Site, Pembroke Street, Cambridge, CB2 3RA (United Kingdom); Xu, Rong [School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive, 637459 (Singapore); Yang, Wenming [Department of Mechanical Engineering, National University of Singapore, Engineering Block EA, Engineering Drive 1, 117576 (Singapore); Kraft, Markus, E-mail: mk306@cam.ac.uk [Department of Chemical Engineering and Biotechnology, University of Cambridge, New Museums Site, Pembroke Street, Cambridge, CB2 3RA (United Kingdom); School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive, 637459 (Singapore)

    2017-02-01

    A new method of moments for solving the population balance equation is developed and presented. The moment projection method (MPM) is numerically simple and easy to implement and attempts to address the challenge of particle shrinkage due to processes such as oxidation, evaporation or dissolution. It directly solves the moment transport equation for the moments and tracks the number of the smallest particles using the algorithm by Blumstein and Wheeler (1973) . The performance of the new method is measured against the method of moments (MOM) and the hybrid method of moments (HMOM). The results suggest that MPM performs much better than MOM and HMOM where shrinkage is dominant. The new method predicts mean quantities which are almost as accurate as a high-precision stochastic method calculated using the established direct simulation algorithm (DSA).

  14. A novel method to assess pial collateralization from stroke perfusion MRI: subdividing T{sub max} into anatomical compartments

    Energy Technology Data Exchange (ETDEWEB)

    Potreck, Arne; Seker, Fatih; Hoffmann, Angelika; Pfaff, Johannes; Bendszus, Martin; Heiland, Sabine; Pham, Mirko [Heidelberg University Hospital, Department of Neuroradiology, Heidelberg (Germany); Nagel, Simon [Heidelberg University Hospital, Department of Neurology, Heidelberg (Germany)

    2017-02-15

    To develop and validate a quantitative and observer-independent method to evaluate pial collateral circulation by DSC-perfusion MRI and test whether this novel method delivers diagnostic information which is redundant to or independent from conventional penumbra imaging by the mismatch approach. We retrospectively identified 47 patients with M1 occlusion who underwent MR diffusion/perfusion imaging and mechanical thrombectomy at our facility. By automated registration and segmentation, T{sub max} delays were attributed specifically to the pial, cortical and parenchymal compartments. The resulting pial volumes at delay were defined as the pial T{sub max} map-assessed collateral score (TMACS) and correlated with gold standard digital subtraction angiography (DSA). Mismatch ratio was assessed by conventional penumbra defining MRI criteria. Strong correlation was found between TMACS and angiographically assessed collateral score (Pearson ρ = -0.74, p < 0.001). In multiple logistic regression, both good collaterals according to TMACS [OR 4.3 (1.1-19, p = 0.04)] and mismatch ratio ≥ 3.5 [OR 12.3 (1.88-249, p = 0.03)] were independent predictors of favourable clinical outcome. Perfusion delay in the pial compartment, as evaluated by TMACS, closely reflects the extent of pial collaterals in gold-standard DSA. TMACS and mismatch ratio were found to be complementary predictors of a favourable clinical outcome, each adding independent predictive information. (orig.)

  15. Follow-up after embolization of ruptured intracranial aneurysms: A prospective comparison of two-dimensional digital subtraction angiography, three-dimensional digital subtraction angiography, and time-of-flight magnetic resonance angiography

    Energy Technology Data Exchange (ETDEWEB)

    Serafin, Zbigniew; Strzesniewski, Piotr; Lasek, Wladyslaw [Nicolaus Copernicus University, Collegium Medicum, Department of Radiology and Diagnostic Imaging, Bydgoszcz (Poland); Beuth, Wojciech [Nicolaus Copernicus University, Collegium Medicum, Department of Neurosurgery and Neurotraumatology, Bydgoszcz (Poland)

    2012-11-15

    To prospectively compare of the diagnostic value of digital subtraction angiography (DSA) and time-of-flight magnetic resonance angiography (TOF-MRA) in the follow-up of intracranial aneurysms after endovascular treatment. Seventy-two consecutive patients were examined 3 months after the embolization. The index tests included: two-dimensional DSA (2D-DSA), three-dimensional DSA (3D-DSA), and TOF-MRA. The reference test was a retrospective consensus between 2D-DSA images, 3D-DSA images, and source rotational DSA images. The evaluation included: detection of the residual flow, quantification of the flow, and validity of the decision regarding retreatment. Intraobserver agreement and interobserver agreement were determined. The sensitivity and specificity of residual flow detection ranged from 84.6 % (2D-DSA and TOF-MRA) to 92.3 % (3D-DSA) and from 91.3 % (TOF-MRA) to 97.8 % (3D-DSA), respectively. The accuracy of occlusion degree evaluation ranged from 0.78 (2D-DSA) to 0.92 (3D-DSA, Cohen's kappa). The 2D-DSA method presented lower performance in the decision on retreatment than 3D-DSA (P < 0.05, ROC analysis). The intraobserver agreement was very good for all techniques ({kappa} = 0.80-0.97). The interobserver agreement was moderate for TOF-MRA and very good for 2D-DSA and 3D-DSA ({kappa} = 0.72-0.94). Considering the invasiveness of DSA and the minor difference in the diagnostic performance between 3D-DSA and TOF-MRA, the latter method should be the first-line modality for follow-up after aneurysm embolization. (orig.)

  16. The oxidation of formaldehyde on high overvoltage DSA type electrodes

    Directory of Open Access Journals (Sweden)

    Motheo Artur J.

    2000-01-01

    Full Text Available The electrochemical oxidation of formaldehyde is studied on dimensionally stable anodes prepared by thermal decomposition of precursors (the corresponding chlorides. The working electrodes used were: Ti/Ir0.3Ti0.7O2, Ti/Ru0.3Ti0.7O2 and Ti/Ir0.2Ru0.2Ti0.6O2. The electrolyses were performed galvanostatically in a filter press cell with 0.5 mol L-1 H2SO4 solutions with initial formaldehyde concentration equal to 100 mmol L-1. The concentration of formaldehyde decreases fast with the electrolysis time, with the ternary anode (Ir + Ru + Ti presenting the best performance for this step. The anode containing only Ir, despite presenting the higher superficial charge, is the one with the lowest electrocatalytic activity. For the formic acid oxidation step, the presence of iridium in the anode composition does not promote the process, the anode containing only ruthenium being the most effective for this step.

  17. Benefits of blended acquisition with dispersed source arrays (DSA)

    NARCIS (Netherlands)

    Caporal, M.; Blacquiere, G.

    2015-01-01

    In blended data acquisition, the recorded wave field is incoherent. Nevertheless blended source units in the arrays are historically chosen to be equal. We propose to abandon this constraint. This allows us to suggest the exploitation of inhomogeneous blended sources, together representing a Dispers

  18. A road map for wireless mesh routing with DSA

    CSIR Research Space (South Africa)

    Maliwatu, R

    2016-09-01

    Full Text Available the University of California Berkeley. Her research looks at the design, deployment, and uptake of new information technologies in the context of socio-economic development. 5GHz WiFi UHF TVWS 2.4GHz WiFi Southern Africa Telecommunication Networks...

  19. [Study on the methods for establishing virtual three-dimensional models of cerebral arteries with the three-dimensional moulding software].

    Science.gov (United States)

    Wei, Xin; Xie, Xiaodong; Wang, Chaohua

    2007-12-01

    This study was conducted to establish the methods of virtual three-dimensional cerebral arteries models by use of three-dimensional moulding software. The virtual models of the cerebral arteries were established using the three-dimensional moulding software of 3D Studio MAX R3 with 46 cases of normal cerebral DSA image as the original. The results showed there was similarity in appearance between the virtual cerebral arteries and DSA image. This is of benefit to understanding the vascular three-dimensional spatial relation in visual sense. Several models of different variant anatomy could be easily established on the copy files of the virtual cerebral arteries model. The virtual model could help learners to create and increase the three-dimensional space concept of arteries and aneurysms in clinical teaching. The results indicated that the virtual three-dimensional cerebral arteries models could display the three-dimensional spatial relation of the cerebral arterial system distinctly, and could serve as a morphologic foundation in the researches on vascular disease.

  20. Manifestations of hepatic cavernous hemangioma in carbon dioxidedigital subtraction angiography

    Institute of Scientific and Technical Information of China (English)

    LU Wei; LI Yan-ha0; HE Xiao-feng; CHEN Yong; ZENG Qing-le

    2002-01-01

    Objective: To describe the characteristic appearance of cavernous hemangioma of the liver (CHL)presented in carbon dioxide digital subtraction angiography (CO2-DSA) and to evaluate the significance of CO2-DSA in the diagnosis of CHL. Methods: Both CO2-DSA and iodinated contrast DSA (IC-DSA) were performed in all 16 patients with CHL, and the angiographic manifestations in the same patients were compared. The image quality was rated by three experienced angiographers, and the complications were also assessed. Results; There was good correlation between angiographers on image quality (R=0. 73). Diagnostic images were obtained with both CO2-DSA and IC-DSA in all CHL patients. No difference was noted between IC-DSA and CO2-DSA in visualizing the proper hepatic arteries and its branches (P>0. 05). CO2-DSA produced better images that clearly described the tumor size, shape and margination than those by IC-DSA (P<0. 05), but both demonstrated characteristic appearances of early opacification and persistent contrast enhancement of the tumors. The portal vein branches near the tumors were constantly demonstrated by CO2-DSA in 15 cases (15/16) but only in 2 cases (2/16) by IC-DSA. Conclusion: CO2-DSA is sensitive in CHL diagnosis, and in patients with contraindications to IC or with unsatisfactory imaging results by IC-DSA,CO2-DSA is a good alternative. As show in most cases by CO2-DSA, the portal veins might act as the main drainage vein of CHLs.

  1. Study on preparing DSA by sol-gel method of rare earth Gd doping SnO2%溶胶-凝胶法制备稀土Gd掺杂SnO2电催化电极的实验研究

    Institute of Scientific and Technical Information of China (English)

    王静; 冯玉杰

    2005-01-01

    本实验采用溶胶-凝胶法,以无机盐SnCl4·5H2O、Sb2O3、Gd(NO3)3为前驱体,制备稀土(Gd)掺杂Sn、Sb溶胶,以钛电极为基材利用该溶胶制备稀土(Gd)掺杂SnO2涂层电极.优化了溶胶-凝胶法制备稀土Gd掺杂SnO2涂层电极的实验条件,研究了在不同加水量、柠檬酸量、pH值等条件下所制备的电极以苯酚为目标有机物的电化学降解特性,对所获得的电极进行了TOC测试及SEM、XRD和XPS等表征,分析并讨论了稀土掺杂对SnO2电极性能的影响机理.结果表明,溶胶-凝胶法制备稀土掺杂SnO2涂层电极是可行的,稀土Gd的掺杂有利于SnO2电极电催化性能的提高,而且不同的加水量、柠檬酸量、pH值对电极性能有一定的影响.本实验条件下,加水量(水与前驱体总量摩尔比)R为36、柠檬酸加入量(柠檬酸与前驱体总量之摩尔比)N为1.0、溶胶pH值为2时所制备的电极降解效果最好,电极最稳定.所获得的电极为纳米涂层电极,其表面涂层中SnO2、Gd2O3等催化活性物质的含量均较高,对苯酚的降解有较好的效果.

  2. The Combined Application of Double-guiding Method and Seldinger Puncture on PCN%双导引与Seldinger技术在PCN中的联合应用

    Institute of Scientific and Technical Information of China (English)

    尹君

    2013-01-01

    目的:回顾性研究超声联合DSA双导引与Seldinger 穿刺法在经皮肾造瘘术(PCN)中的应用,分析其技术成功率与并发症的发生率。方法247例接受 PCN的泌尿系梗阻患者,其中急性梗阻48例,慢性梗阻199例,两组均先在超声导引下采取Seldinger技术穿刺积水肾盂,成功后移至 DSA下操作。结果两组均无严重并发症发生,无操作相关死亡病例;普通并发症两组间仅出血发生率有显著性差异(P=0.019)。结论超声联合DSA双导引与Seldinger 穿刺法应用于PCN中,操作简单,成功率高,并发症少且无严重并发症,值得在临床工作中推广应用。%ObjectiveTo study the combined application of the Seldinger puncture under the ultrasound and DSA on percutaneous nephrostomy (PCN) technique, and to analysis the success rate and the incidence of complications. Materials and Methods Of 247 patients with urinary tract obstruction, 48 cases of acute and 199 chronic obstruction were al underwent PCN by Seldinger puncture under ultrasound and DSA. Results In both groups no serious complications occurred, and no dead cases did;in common complications , only incidence of hematuria between the two groups have significant dif erence (P=0.019). Conclusion PCN by Seldinger puncture under ultrasound and DSA, has the features of the simple operation,high success rate,less complications and no serious complications, worthy of popularization in clinical practice.

  3. Assessment of New Calculation Method for Toxicological Sums-of-Fractions for Hanford Tank Wastes

    Energy Technology Data Exchange (ETDEWEB)

    Mahoney, Lenna A.

    2006-09-26

    The toxicological source terms used for potential accident assessment in the Tank Farms DSA are based on toxicological sums-of-fractions (SOFs) that were calculated in fiscal years 2002 and 2003 based on the Best Basis Inventory (BBI) from May 2002, using the method described by Cowley et al. (2003). The present report describes a modified SOF-calculation method that is to be used in future toxicological updates and assessments and compares its results (for the 2002 BBI) to those of the old method. The new method generally calculated different (usually larger) SOFs than the old. The dominant reason was the more conservative way in which the new method represents concentration variability, in that it uses the waste layer with the maximum SOF to represent the tank SOF. The old method had used a tank-average waste composition and SOF. Differences between thermodynamically modeled and BBI solubilities were the next most common reason for differences between old (modeled) and new (BBI) SOFs, particularly in the liquid phase. The solubility-related changes in SOF were roughly equally distributed between increases and decreases. Changes in the effective toxicities of TOC and lead, which resulted from changes in the compounds in which these analytes were considered to be present, were the third most common reason. These toxicity changes increased SOFs and therefore were in a conservative direction.

  4. Weather data for simplified energy calculation methods. Volume I. Eastern United States: TRY data

    Energy Technology Data Exchange (ETDEWEB)

    Olsen, A.R.; Moreno, S.; Deringer, J.; Watson, C.R.

    1984-08-01

    The objective of this report is to provide a source of weather data for direct use with a number of simplified energy calculation methods available today. Complete weather data for a number of cities in the United States are provided for use in the following methods: degree hour, modified degree hour, bin, modified bin, and variable degree day. This report contains sets of weather data for 23 cities in the continental United States using Test Reference Year (TRY) source weather data. The weather data at each city has been summarized in a number of ways to provide differing levels of detail necessary for alternative simplified energy calculation methods. Weather variables summarized include dry bulb and wet bulb temperature, percent relative humidity, humidity ratio, wind speed, percent possible sunshine, percent diffuse solar radiation, total solar radiation on horizontal and vertical surfaces, and solar heat gain through standard DSA glass. Monthly and annual summaries, in some cases by time of day, are available. These summaries are produced in a series of nine computer generated tables.

  5. Weather data for simplified energy calculation methods. Volume II. Middle United States: TRY data

    Energy Technology Data Exchange (ETDEWEB)

    Olsen, A.R.; Moreno, S.; Deringer, J.; Watson, C.R.

    1984-08-01

    The objective of this report is to provide a source of weather data for direct use with a number of simplified energy calculation methods available today. Complete weather data for a number of cities in the United States are provided for use in the following methods: degree hour, modified degree hour, bin, modified bin, and variable degree day. This report contains sets of weather data for 22 cities in the continental United States using Test Reference Year (TRY) source weather data. The weather data at each city has been summarized in a number of ways to provide differing levels of detail necessary for alternative simplified energy calculation methods. Weather variables summarized include dry bulb and wet bulb temperature, percent relative humidity, humidity ratio, wind speed, percent possible sunshine, percent diffuse solar radiation, total solar radiation on horizontal and vertical surfaces, and solar heat gain through standard DSA glass. Monthly and annual summaries, in some cases by time of day, are available. These summaries are produced in a series of nine computer generated tables.

  6. Weather data for simplified energy calculation methods. Volume IV. United States: WYEC data

    Energy Technology Data Exchange (ETDEWEB)

    Olsen, A.R.; Moreno, S.; Deringer, J.; Watson, C.R.

    1984-08-01

    The objective of this report is to provide a source of weather data for direct use with a number of simplified energy calculation methods available today. Complete weather data for a number of cities in the United States are provided for use in the following methods: degree hour, modified degree hour, bin, modified bin, and variable degree day. This report contains sets of weather data for 23 cities using Weather Year for Energy Calculations (WYEC) source weather data. Considerable overlap is present in cities (21) covered by both the TRY and WYEC data. The weather data at each city has been summarized in a number of ways to provide differing levels of detail necessary for alternative simplified energy calculation methods. Weather variables summarized include dry bulb and wet bulb temperature, percent relative humidity, humidity ratio, wind speed, percent possible sunshine, percent diffuse solar radiation, total solar radiation on horizontal and vertical surfaces, and solar heat gain through standard DSA glass. Monthly and annual summaries, in some cases by time of day, are available. These summaries are produced in a series of nine computer generated tables.

  7. A novel method of defective vascular reconstruction using 2-octyl-cyanoacrylate and homemade prosthetic component

    Institute of Scientific and Technical Information of China (English)

    Liang Xiangdang; Cai Hongfei; Sun Geng; Liu Zihao; Chen Wen; Tang Peifu

    2014-01-01

    Background Currently,adhesive technique is popular in vascular repair but not widely used for defective vessels.This study aimed to determine the feasibility and effectiveness of repairing defective vessels with 2-octyl-cyanoacrylate and a homemade prosthetic component.Methods Homemade prosthetic component consisting of expanded polytetrofluoroethylene (ePTFE),terylene film,and homemade soluble hollow stent mixed with adhesive can replace autologous graft and suture in repairing defective vessels,can fix vessels better using the stent without occlusive bleeding.Forty male mongrel dogs were used,20 for biomechanical tests and 20 for animal experiments.In the biomechanical test,dogs were randomly divided into two groups (n=10 each),one group repaired on the two sides of the carotid arteries with 2-octyl-cyanoacrylate and homemade component and another group repaired with suture and ePTFE.Of the 40 specimens,10 were used for adhesive and 10 for suture specimens for tension strength test,whereas the remaining specimens were used for bursting pressure test.In animal experiments,dogs were also divided into adhesive and suture groups (n=10),only of the left carotid artery.Recording the operational time,bleeding or not.Vessels were tested using color Doppler ultrasound,the inner diameter was measured,and the degree of stenosis at 8 weeks was evaluated digital subtraction angiography (DSA) were also performed.Specimens were then analyzed histologically.Results In the adhesive and suture groups,the specimens could afford atension strength of (23.80±1.51) N versus (24.60±1.08) N (P >0.05),the bursting pressure was (52.03±.2.43) kPa versus (50.04±3.51) kPa (P >0.05),and the mean time of anastomosis was (15.20±0.55) minutes versus (25.97±0.58) minutes (P <0.05).One dog in the adhesive group was bleeding from the suture.One dog from each group presented with thrombosis at 1 week.After measuring using ultrasound,the stenosis degree of all dogs were no more than 30

  8. CT Angiographic Analysis of Carotid Artery Stenosis: Comparison of Manual Assessment, Semiautomatic Vessel Analysis, and Digital Subtraction Angiography

    National Research Council Canada - National Science Library

    Silvennoinen, H.M; Ikonen, S; Soinne, L; Railo, M; Valanne, L

    2007-01-01

    ...) in detection and grading of carotid artery bifurcation stenosis. METHODS: Consecutive patients with sonography evidence of a marked internal carotid artery stenosis underwent both carotid CTA and DSA...

  9. Perturbation methods

    CERN Document Server

    Nayfeh, Ali H

    2008-01-01

    1. Introduction 1 2. Straightforward Expansions and Sources of Nonuniformity 23 3. The Method of Strained Coordinates 56 4. The Methods of Matched and Composite Asymptotic Expansions 110 5. Variation of Parameters and Methods of Averaging 159 6. The Method of Multiple Scales 228 7. Asymptotic Solutions of Linear Equations 308 References and Author Index 387 Subject Index 417

  10. Use of complement binding assays to assess the efficacy of antibody mediated rejection therapy and prediction of graft survival in kidney transplantation.

    Science.gov (United States)

    Ramon, Daniel S; Huang, Yihung; Zhao, Lili; Rendulic, TrisAnn; Park, Jeong M; Sung, Randall S; Samaniego, Milagros

    2017-02-01

    The Luminex® single antigen bead assay (SAB) is the method of choice for monitoring the treatment for antibody-mediated rejection (AMR). A ⩾50% reduction of the dominant donor-specific antibody (IgG-DSA) mean fluorescence intensity (MFI) has been associated with improved kidney allograft survival, and C1q-fixing DSA activity is associated with poor outcomes in patients with AMR. We aimed to investigate if C1q-DSA can be used as a reliable predictor of response to therapy and allograft survival in patients with biopsy-proven AMR. We tested pre- and post-treatment sera of 30 kidney transplant patients receiving plasmapheresis and low-dose IVIG for biopsy-proven AMR. IgG-DSA and C1q-DSA MFI were measured and correlated with graft loss or survival. Patients were classified as nonresponders (NR) when treatment resulted in <50% reduction in MFI of IgG-DSA and/or C1q-DSA was detectable following therapy. Differences in the percentage of patients deemed NR depended upon the end-point criterion (73% by reduction in IgG-DSA MFI vs. 50% by persistent C1q-DSA activity). None of the seven patients with <50% reduction of IgG-DSA but non-detectable C1q-DSA-fixing activity after therapy experienced graft loss, suggesting that C1q-DSA activity may better correlate with response. Reduction of C1q-DSA activity predicted graft survival better than IgG-DSA in the univariate Cox analysis (20.1% vs. 5.9% in NR; log-rank P-value=0.0147). A rapid reduction of DSA concentration below the threshold required for complement activation is associated with better graft survival, and C1q-DSA is a better predictor of outcomes than IgG-DSA MFI reduction. Copyright © 2016 American Society for Histocompatibility and Immunogenetics. Published by Elsevier Inc. All rights reserved.

  11. Clinical validation and performance evaluation of enhancement methods acquired from interventional C-ARM x-ray

    Science.gov (United States)

    Wei, Liyang; Kumar, Dinesh; Khemka, Animesh; Turlapati, Ram; Suri, Jasjit S.

    2008-03-01

    Digital Subtraction Angiography (DSA) is a well-established powerful modality for the visualization of stenosis and blood vessels in general. This paper presents two novel approaches which address image quality. In the first approach we combine anisotropic diffusion with nonlinear normalization. The second approach consists of an introduction of a regularization strategy followed by a classification procedure to improve the enhancement. The performances of two strategies are evaluated based on a database of 73 subjects using SNR, CNR and Tenengrad's metric. Compared with conventional DSA, Eigen's diffusion embedded nonlinear enhancement strategies can improve image quality 95.25% in terms of SNR. The regularization embedded linear enhancement strategy can also improve SNR 51.46% compared with conventional DSA. Similar results are obtained by CNR and Tenengrad's metric measurements. Our system runs on a PC-based workstation using C++ in Windows environment.

  12. Nanoimprint, DSA, and multi-beam lithography: patterning technologies with new integration challenges

    Science.gov (United States)

    Landis, S.; Teyssedre, H.; Claveau, G.; Servin, I.; Delachat, F.; Pourteau, M. L.; Gharbi, A.; Pimenta Barros, P.; Tiron, R.; Nouri, L.; Possemé, N.; May, M.; Brianceau, P.; Barnola, S.; Blancquaert, Y.; Pradelles, J.; Essomba, P.; Bernadac, A.; Dal'zotto, B.; Bos, S.; Argoud, M.; Chamiot-Maitral, G.; Sarrazin, A.; Tallaron, C.; Lapeyre, C.; Pain, L.

    2017-04-01

    In the lithography landscape, EUV technology recovered some credibility recently. However, its large adoption remains uncertain. Meanwhile, 193nm immersion lithography, with multiple-patterning strategies, supports the industry preference for advanced-node developments. In this landscape, lithography alternatives maintain promise for continued R&D. Massively parallel electron-beam and nano-imprint lithography techniques remain highly attractive, as they can provide noteworthy cost-of-ownership benefits. Directed self-assembly lithography shows promising resolution capabilities and appears to be an option to reduce multi-patterning strategies. Even if large amount of efforts are dedicated to overcome the lithography side issues, these solutions introduce also new challenges and opportunities for the integration schemes.

  13. Electrochemical degradation of diuron in chloride medium using DSA Registered-Sign based anodes

    Energy Technology Data Exchange (ETDEWEB)

    Pipi, Angelo R. F.; Aquino Neto, Sidney; Andrade, Adalgisa R. de, E-mail: ardandra@ffclrp.usp.br [Departamento de Quimica, Faculdade de Filosofia Ciencias e Letras de Ribeirao Preto, Universidade de Sao Paulo, Ribeirao Preto-SP (Brazil)

    2013-07-15

    This work presents a study of the electrochemical degradation of the herbicide diuron using Ti/Ru{sub x}Ti{sub (1-x)}O{sub 2} and Ti/Ir{sub x}Ti{sub (1-x)}O{sub 2} (x 0.3, 0.5 and 0.7) anodes. The investigation of the degradation was conducted in the presence and in the absence of chloride. The study of the herbicide removal as a function of the current density in the absence of chloride yielded 41 and 49% COD (chemical oxygen demand) removals and 10 and 14% TOC (total organic carbon) removal at 100 mA cm{sup -2}, respectively. By keeping the electrolysis time constant (4 h), Ti/Ru{sub 0.7}Ti{sub 0.3}O{sub 2} anode composition was determined as the most active for removal of diuron and its byproduct. The maximum removal value achieved after 4 h was 58%. Addition of chloride doubled the removal ratio, and 100% COD removal was obtained for Ti/Ru{sub 0.3}Ti{sub 0.7}O{sub 2} . High-performance liquid chromatography (HPLC) analysis confirmed the total removal of the herbicide in chloride medium and indicated the formation of byproducts. The generated byproducts presented as function of the applied current density and the anode composition. Ir-based anodes promoted milder oxidation and furnished more byproducts in aqueous medium. (author)

  14. 东芝DSA mA过低故障维修1例

    Institute of Scientific and Technical Information of China (English)

    夏钢伟

    2006-01-01

    @@ 机型 INFINIX-VCI 故障现象在做F-mA ADJUST(SF/MF/LF时,发现较高的HEAT DATA出来的NE-mA/ACT-mA很低,并且在做calculate时出现"calculate error"提示,在作R-mA adjust时NE-mA/ACT-MA也比工厂提供的数据低很多,但在做calculate时不出错,但heat data曲线很高.正常界面下曝光不出错.

  15. Procedures for imaging of hemodialysis fistulas with particular reference to digital subtraction angiography (DSA)

    Energy Technology Data Exchange (ETDEWEB)

    Neufang, K.F.R.; Erasmi-Koerber, H.; Wimmer, G.

    1983-05-01

    All angiographic procedures established for imaging of hemodialysis fistulas, such as direct venous angiography, intravenous subtraction angiography and arteriography by direct puncture of the brachial artery by Seldinger's transfemoral technique, can also be effected with digital image processing. Depending on the angiographic technique, the use of digital subtraction angiography has several advantages: lower doses and concentrations of the contrast agent, lower risk of complications (thrombosis of the fistula, vasospasm) and freedom from pain. In addition, there is a marked reduction of examination time and film cost.

  16. Identification of a Unique Ganglioside Binding Loop within Botulinum Neurotoxins C and D-SA

    Energy Technology Data Exchange (ETDEWEB)

    Karalewitz, Andrew P.-A.; Kroken, Abby R.; Fu, Zhuji; Baldwin, Michael R.; Kim, Jung-Ja P.; Barbieri, Joseph T. (MCW); (Missouri)

    2010-09-22

    The botulinum neurotoxins (BoNTs) are the most potent protein toxins for humans. There are seven serotypes of BoNTs (A-G) based on a lack of cross antiserum neutralization. BoNTs utilize gangliosides as components of the host receptors for binding and entry into neurons. Members of BoNT/C and BoNT/D serotypes include mosaic toxins that are organized in D/C and C/D toxins. One D/C mosaic toxin, BoNT/D-South Africa (BoNT/D-SA), was not fully neutralized by immunization with BoNT serotype C or D, which stimulated this study. Here the crystal structures of the receptor binding domains of BoNT/C, BoNT/D, and BoNT/D-SA are presented. Biochemical and cell binding studies show that BoNT/C and BoNT/D-SA possess unique mechanisms for ganglioside binding. These studies provide new information about how the BoNTs can enter host cells as well as a basis for understanding the immunological diversity of these neurotoxins.

  17. Privacy for Semantic Web Mining using Advanced DSA – Spatial LBS Case Study in mining

    Directory of Open Access Journals (Sweden)

    S.Nagaprasad Sri

    2010-09-01

    Full Text Available The Web Services paradigm promises to enable rich flexible and dynamic interoperation of highly distributed, heterogeneous network enabled services. The idea of Web Services Mining that it makes use of the findings in the field of data mining and applies them to the world of Web Services. The emerging concept of Semantic Web Services aims at more sophisticated Web Services technologies: on basis of Semantic Description Frameworks, Intelligent mechanisms are envisioned for Discovery, Composition, and contracting of Web Services. The aim of semantic web is not only to support to access information on the web but also to support its usage. Geospatial Semantic Web is an augmentation to the Semantic Web that adds geospatial abstractions, as well as related reasoning, representation and query mechanisms. Web Service Security represents a key requirement for today’s distributed interconnected digital world and for the new generations, Web 2.0 and Semantic Web. To date, the problem of security has been investigated very much in the context of standardization efforts; Personal judgments are made usually based on the sensitivity of the information and the reputation of the party to which the information is to be disclosed. On the privacy front, this means that privacy invasion would net more quality and sensitive personal information. In this paper, we had implemented a case study on integrated privacy issues of Spatial Semantic Web Services Mining. Initially we improved privacy of Geospatial Semantic Layer. Finally, we implemented a Location Based System and improved its digital signature capability, using advanced Digital Signature standards.

  18. Privacy for Semantic Web Mining using Advanced DSA – Spatial LBS Case Study

    Directory of Open Access Journals (Sweden)

    Dr.D.Sravan Kumar,

    2010-05-01

    Full Text Available The Web Services paradigm promises to enable rich flexible and dynamic interoperation of highly distributed, heterogeneous network enabled services. The idea of Web Services Mining that it makes use of the findings in the field of data mining and applies them to the world of Web Services. The emerging concept of Semantic Web Services aims at more sophisticated Web Services technologies: on basis of Semantic Description Frameworks, Intelligent mechanisms are envisioned for Discovery, Composition, and contracting of Web Services. The aim of semantic web is not only to support to access information on the web but also to support its usage. Geospatial Semantic Web is an augmentation to the Semantic Web that adds geospatial abstractions, as well as related reasoning, representation and query mechanisms. Web Service Security represents a key requirement for today’s distributed interconnected digital world and for the new generations, Web 2.0 and Semantic Web. To date, the problem of security has been investigated very much in the context of standardization efforts; Personal judgments are made usually based on the sensitivity of the information and the reputation of the party towhich the information is to be disclosed. On the privacy front,this means that privacy invasion would net more quality and sensitive personal information. In this paper, we had implemented a case study on integrated privacy issues of Spatial Semantic Web Services Mining. Initially we improved privacy of Geospatial Semantic Layer. Finally, we implemented a Location Based System and improved its digital signature capability, using advanced Digital Signature standards.

  19. Vortex methods

    Energy Technology Data Exchange (ETDEWEB)

    Chorin, A.J. [California Univ., Berkeley, CA (United States). Dept. of Mathematics]|[Lawrence Berkeley Lab., CA (United States)

    1993-06-01

    Vortex methods originated from the observation that in incompressible inviscid flow vorticity (or, more accurately, circulation) is a conserved quantity, as can be readily deduced from the absence of tangential stresses. Thus, if the vorticity is known at time t=0, one can find the flow at a later time by simply following the vorticity. In this narrow context, a vortex method is a numerical method that follows vorticity. The author restricts himself in these lectures to a special class of numerical vortex methods, those that are based on a Lagrangian transport of vorticity in hydrodynamics by smoothed particles (blobs) and those whose analysis contributes to the understanding of blob methods. Blob methods started in the 1930`s.

  20. Mining Method

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young Shik; Lee, Kyung Woon; Kim, Oak Hwan; Kim, Dae Kyung [Korea Institute of Geology Mining and Materials, Taejon (Korea, Republic of)

    1996-12-01

    The reducing coal market has been enforcing the coal industry to make exceptional rationalization and restructuring efforts since the end of the eighties. To the competition from crude oil and natural gas has been added the growing pressure from rising wages and rising production cost as the workings get deeper. To improve the competitive position of the coal mines against oil and gas through cost reduction, studies to improve mining system have been carried out. To find fields requiring improvements most, the technologies using in Tae Bak Colliery which was selected one of long running mines were investigated and analyzed. The mining method appeared the field needing improvements most to reduce the production cost. The present method, so-called inseam roadway caving method presently is using to extract the steep and thick seam. However, this method has several drawbacks. To solve the problems, two mining methods are suggested for a long term and short term method respectively. Inseam roadway caving method with long-hole blasting method is a variety of the present inseam roadway caving method modified by replacing timber sets with steel arch sets and the shovel loaders with chain conveyors. And long hole blasting is introduced to promote caving. And pillar caving method with chock supports method uses chock supports setting in the cross-cut from the hanging wall to the footwall. Two single chain conveyors are needed. One is installed in front of chock supports to clear coal from the cutting face. The other is installed behind the supports to transport caved coal from behind. This method is superior to the previous one in terms of safety from water-inrushes, production rate and productivity. The only drawback is that it needs more investment. (author). 14 tabs., 34 figs.

  1. Projection Methods

    DEFF Research Database (Denmark)

    Wagner, Falko Jens; Poulsen, Mikael Zebbelin

    1999-01-01

    When trying to solve a DAE problem of high index with more traditional methods, it often causes instability in some of the variables, and finally leads to breakdown of convergence and integration of the solution. This is nicely shown in [ESF98, p. 152 ff.].This chapter will introduce projection...... methods as a way of handling these special problems. It is assumed that we have methods for solving normal ODE systems and index-1 systems....

  2. Computing methods

    CERN Document Server

    Berezin, I S

    1965-01-01

    Computing Methods, Volume 2 is a five-chapter text that presents the numerical methods of solving sets of several mathematical equations. This volume includes computation sets of linear algebraic equations, high degree equations and transcendental equations, numerical methods of finding eigenvalues, and approximate methods of solving ordinary differential equations, partial differential equations and integral equations.The book is intended as a text-book for students in mechanical mathematical and physics-mathematical faculties specializing in computer mathematics and persons interested in the

  3. The Indoor Localization and Tracking Estimation Method of Mobile Targets in Three-Dimensional Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Zixi Jia

    2015-11-01

    Full Text Available Indoor localization is a significant research area in wireless sensor networks (WSNs. Generally, the nodes of WSNs are deployed in the same plane, i.e., the floor, as the target to be positioned, which causes the sensing signal to be influenced or even blocked by unpredictable obstacles, like furniture. However, a 3D system, like Cricket, can reduce the negative impact of obstacles to the maximum extent and guarantee the sensing signal transmission by using the line of sight (LOS. However, most of the traditional localization methods are not available for the new deployment mode. In this paper, we propose the self-localization of beacons method based on the Cayley–Menger determinant, which can determine the positions of beacons stuck in the ceiling; and differential sensitivity analysis (DSA is also applied to eliminate measurement errors in measurement data fusion. Then, the calibration of beacons scheme is proposed to further refine the locations of beacons by the mobile robot. According to the robot’s motion model based on dead reckoning, which is the process of determining one’s current position, we employ the H ∞ filter and the strong tracking filter (STF to calibrate the rough locations, respectively. Lastly, the optimal node selection scheme based on geometric dilution precision (GDOP is presented here, which is able to pick the group of beacons with the minimum GDOP from all of the beacons. Then, we propose the GDOP-based weighting estimation method (GWEM to associate redundant information with the position of the target. To verify the proposed methods in the paper, we design and conduct a simulation and an experiment in an indoor setting. Compared to EKF and the H ∞ filter, the adopted STF method can more effectively calibrate the locations of beacons; GWEM can provide centimeter-level precision in 3D environments by using the combination of beacons that minimizes GDOP.

  4. The Indoor Localization and Tracking Estimation Method of Mobile Targets in Three-Dimensional Wireless Sensor Networks.

    Science.gov (United States)

    Jia, Zixi; Wu, Chengdong; Li, Zhao; Zhang, Yunzhou; Guan, Bo

    2015-11-24

    Indoor localization is a significant research area in wireless sensor networks (WSNs). Generally, the nodes of WSNs are deployed in the same plane, i.e., the floor, as the target to be positioned, which causes the sensing signal to be influenced or even blocked by unpredictable obstacles, like furniture. However, a 3D system, like Cricket, can reduce the negative impact of obstacles to the maximum extent and guarantee the sensing signal transmission by using the line of sight (LOS). However, most of the traditional localization methods are not available for the new deployment mode. In this paper, we propose the self-localization of beacons method based on the Cayley-Menger determinant, which can determine the positions of beacons stuck in the ceiling; and differential sensitivity analysis (DSA) is also applied to eliminate measurement errors in measurement data fusion. Then, the calibration of beacons scheme is proposed to further refine the locations of beacons by the mobile robot. According to the robot's motion model based on dead reckoning, which is the process of determining one's current position, we employ the H∞ filter and the strong tracking filter (STF) to calibrate the rough locations, respectively. Lastly, the optimal node selection scheme based on geometric dilution precision (GDOP) is presented here, which is able to pick the group of beacons with the minimum GDOP from all of the beacons. Then, we propose the GDOP-based weighting estimation method (GWEM) to associate redundant information with the position of the target. To verify the proposed methods in the paper, we design and conduct a simulation and an experiment in an indoor setting. Compared to EKF and the H∞ filter, the adopted STF method can more effectively calibrate the locations of beacons; GWEM can provide centimeter-level precision in 3D environments by using the combination of beacons that minimizes GDOP.

  5. Method 59

    DEFF Research Database (Denmark)

    Kjellsson, G.

    1994-01-01

    OCDE/GD(94)41. Er supplerende rapport til rapport: The OECD Workshop on Methods for Monitoring Organisms in the Environment, Ottawa 14-17 September 1992. Environment Monograph 90.......OCDE/GD(94)41. Er supplerende rapport til rapport: The OECD Workshop on Methods for Monitoring Organisms in the Environment, Ottawa 14-17 September 1992. Environment Monograph 90....

  6. Method Mixins

    DEFF Research Database (Denmark)

    Ernst, Erik

    2005-01-01

    , where traditional invocation is optimized for as-is reuse of existing behavior. Tight coupling reduces flexibility, and traditional invocation tightly couples transfer of information and transfer of control. Method mixins decouple these two kinds of transfer, thereby opening the doors for new kinds......The world of programming has been conquered by the procedure call mechanism, including object-oriented method invocation which is a procedure call in context of an object. This paper presents an alternative, method mixin invocations, that is optimized for flexible creation of composite behavior...

  7. Method Mixins

    DEFF Research Database (Denmark)

    Ernst, Erik

    2002-01-01

    invocation is optimized for as-is reuse of existing behavior. Tight coupling reduces flexibility, and traditional invocation tightly couples transfer of information and transfer of control. Method mixins decouple these two kinds of transfer, thereby opening the doors for new kinds of abstraction and reuse......The procedure call mechanism has conquered the world of programming, with object-oriented method invocation being a procedure call in context of an object. This paper presents an alternative, method mixin invocations, that is optimized for flexible creation of composite behavior, where traditional...

  8. Dosimetry methods

    DEFF Research Database (Denmark)

    McLaughlin, W.L.; Miller, A.; Kovacs, A.;

    2003-01-01

    Chemical and physical radiation dosimetry methods, used for the measurement of absorbed dose mainly during the practical use of ionizing radiation, are discussed with respect to their characteristics and fields of application.......Chemical and physical radiation dosimetry methods, used for the measurement of absorbed dose mainly during the practical use of ionizing radiation, are discussed with respect to their characteristics and fields of application....

  9. Ensemble Methods

    Science.gov (United States)

    Re, Matteo; Valentini, Giorgio

    2012-03-01

    Ensemble methods are statistical and computational learning procedures reminiscent of the human social learning behavior of seeking several opinions before making any crucial decision. The idea of combining the opinions of different "experts" to obtain an overall “ensemble” decision is rooted in our culture at least from the classical age of ancient Greece, and it has been formalized during the Enlightenment with the Condorcet Jury Theorem[45]), which proved that the judgment of a committee is superior to those of individuals, provided the individuals have reasonable competence. Ensembles are sets of learning machines that combine in some way their decisions, or their learning algorithms, or different views of data, or other specific characteristics to obtain more reliable and more accurate predictions in supervised and unsupervised learning problems [48,116]. A simple example is represented by the majority vote ensemble, by which the decisions of different learning machines are combined, and the class that receives the majority of “votes” (i.e., the class predicted by the majority of the learning machines) is the class predicted by the overall ensemble [158]. In the literature, a plethora of terms other than ensembles has been used, such as fusion, combination, aggregation, and committee, to indicate sets of learning machines that work together to solve a machine learning problem [19,40,56,66,99,108,123], but in this chapter we maintain the term ensemble in its widest meaning, in order to include the whole range of combination methods. Nowadays, ensemble methods represent one of the main current research lines in machine learning [48,116], and the interest of the research community on ensemble methods is witnessed by conferences and workshops specifically devoted to ensembles, first of all the multiple classifier systems (MCS) conference organized by Roli, Kittler, Windeatt, and other researchers of this area [14,62,85,149,173]. Several theories have been

  10. Statistical methods

    CERN Document Server

    Szulc, Stefan

    1965-01-01

    Statistical Methods provides a discussion of the principles of the organization and technique of research, with emphasis on its application to the problems in social statistics. This book discusses branch statistics, which aims to develop practical ways of collecting and processing numerical data and to adapt general statistical methods to the objectives in a given field.Organized into five parts encompassing 22 chapters, this book begins with an overview of how to organize the collection of such information on individual units, primarily as accomplished by government agencies. This text then

  11. Sieve methods

    CERN Document Server

    Halberstam, Heine

    2011-01-01

    Derived from the techniques of analytic number theory, sieve theory employs methods from mathematical analysis to solve number-theoretical problems. This text by a noted pair of experts is regarded as the definitive work on the subject. It formulates the general sieve problem, explores the theoretical background, and illustrates significant applications.""For years to come, Sieve Methods will be vital to those seeking to work in the subject, and also to those seeking to make applications,"" noted prominent mathematician Hugh Montgomery in his review of this volume for the Bulletin of the Ameri

  12. Spectral Methods

    CERN Document Server

    Shen, Jie; Wang, Li-Lian

    2011-01-01

    Along with finite differences and finite elements, spectral methods are one of the three main methodologies for solving partial differential equations on computers. This book provides a detailed presentation of basic spectral algorithms, as well as a systematical presentation of basic convergence theory and error analysis for spectral methods. Readers of this book will be exposed to a unified framework for designing and analyzing spectral algorithms for a variety of problems, including in particular high-order differential equations and problems in unbounded domains. The book contains a large

  13. Statistical methods

    CERN Document Server

    Freund, Rudolf J; Wilson, William J

    2010-01-01

    Statistical Methods, 3e provides students with a working introduction to statistical methods offering a wide range of applications that emphasize the quantitative skills useful across many academic disciplines. This text takes a classic approach emphasizing concepts and techniques for working out problems and intepreting results. The book includes research projects, real-world case studies, numerous examples and data exercises organized by level of difficulty. This text requires that a student be familiar with algebra. New to this edition: NEW expansion of exercises a

  14. Digital subtraction angiography and intraarterial contrast medium injection for coronary examinations

    Energy Technology Data Exchange (ETDEWEB)

    Tobio, R.; Kallmeyer, C.; Castello, J.

    1985-01-01

    Digital subtraction angiography (DSA) is an established method of vasography, most extensively used as i.v. DSA. Intraarterial injection, however, applying selective or non-selective contrast medium injection, seems to be at least as important a technique although it has not yet met with corresponding interest. The article explains advantages of the technique for angiographic examinations, in particular of coronary angiography.

  15. Equine deep stromal abscesses (51 cases - 2004-2009) - part 1

    DEFF Research Database (Denmark)

    de Linde Henriksen, Michala; Andersen, Pia H; Thomsen, Preben D;

    2014-01-01

    OBJECTIVE: To study the equine deep stromal abscesses (DSA) with focus on the duration of the corneal disease, medical treatment, season of presentation, clinical appearance, and the degree of corneal vascularization. MATERIAL AND METHODS: Equine DSA diagnosed, biopsied, and surgically treated...

  16. Digital Methods

    NARCIS (Netherlands)

    Rogers, R.

    2013-01-01

    In Digital Methods, Richard Rogers proposes a methodological outlook for social and cultural scholarly research on the Web that seeks to move Internet research beyond the study of online culture. It is not a toolkit for Internet research, or operating instructions for a software package; it deals wi

  17. Characterization methods

    Energy Technology Data Exchange (ETDEWEB)

    Glass, J.T. [North Carolina State Univ., Raleigh (United States)

    1993-01-01

    Methods discussed in this compilation of notes and diagrams are Raman spectroscopy, scanning electron microscopy, transmission electron microscopy, and other surface analysis techniques (auger electron spectroscopy, x-ray photoelectron spectroscopy, electron energy loss spectroscopy, and scanning tunnelling microscopy). A comparative evaluation of different techniques is performed. In-vacuo and in-situ analyses are described.

  18. Radiofluorination method

    DEFF Research Database (Denmark)

    2014-01-01

    A method of conducting radiofluorination of a substrate, comprising the steps of: (a) contacting an aqueous solution of [18F] fluoride with a polymer supported phosphazene base for sufficient time for trapping of [18F] fluoride on the polymer supported phosphazene base; and (b) contacting...

  19. Contraceptive Methods.

    Science.gov (United States)

    Colquitt, Charlie W; Martin, Tonya S

    2017-02-01

    The prevention of pregnancy remains an important part of the practice of medicine. Contraception can occur at a number of points in the basic reproductive biological process and through a number of contraceptive product options. Pharmacists are health care providers appropriately positioned to assist patients in suitable contraceptive product selection based on their personal situations and lifestyles. This article provides an overview of available products for prevention of pregnancy and associated risks and benefits. Contraceptive products are categorized by their hormonal content and method of action. Hormonal options include oral contraceptive pills, contraceptive patch, implants, injection, intravaginal, and intrauterine devices. Barrier products prevent pregnancy by creating a physical obstacle to the successful fertilization of an egg by sperm. All products and methods are associated with benefits and potential complications that must be considered as patients, and health care providers select the most satisfactory option.

  20. Numerical methods

    CERN Document Server

    Dahlquist, Germund

    2003-01-01

    ""Substantial, detailed and rigorous . . . readers for whom the book is intended are admirably served."" - MathSciNet (Mathematical Reviews on the Web), American Mathematical Society.Practical text strikes fine balance between students' requirements for theoretical treatment and needs of practitioners, with best methods for large- and small-scale computing. Prerequisites are minimal (calculus, linear algebra, and preferably some acquaintance with computer programming). Text includes many worked examples, problems, and an extensive bibliography.

  1. Evaluation of the methods in assessment of intracranial collateral pathways for safe surgery of the carotid artery%颈动脉手术围术期预测脑侧支循环的方法评价

    Institute of Scientific and Technical Information of China (English)

    张志愿; 郑家伟; 范新东

    2005-01-01

    To prediet the pateney of the cirele of Willis and cerebral ischemia during earotid artery surgery (ligation, resection, revascularization) is of rtmost importance both for the surgeons and the patients. Many methods have been proposed in the literature as simple and accurate means of evaluation the adequacy of cullateral hemispheric blood flow to compensate for a potentially resectable earoted artery. including Matas test, DSA, intraoperative measurement of stump pressure or back pressure, preoperative and intraoperative EEC monitoring, ocular plethysmograph (OPG),temporary balloon neelusion (TBO) alone or with single photon emission computerized tomography (SPECT). venon-enhanced computed tomography cerebral blood flow (Xe/CT CBF), and transcranial color Doppler (TCD). However, there is no single review and elinical studies showed that the combination of preoperative TBO and SPECT cerebral blood flow imaging significantly increases the safety of ICA/CCA resection, which can be used rontinely to predict the patients'tolerance for earotid artery sacrifiee sithout developing neurologie deficits. Supported by Research Fund of the Ministry of Public Health (Grant No.96-1-340) and Sustentation Plan for Excellent Aeademic Leader of Shanghai Munieipality (Grant No.96XD14013).

  2. C1Q Assay Results in Complement-Dependent Cytotoxicity Crossmatch Negative Renal Transplant Candidates with Donor-Specific Antibodies: High Specificity but Low Sensitivity When Predicting Flow Crossmatch

    Directory of Open Access Journals (Sweden)

    José M. Arreola-Guerra

    2016-01-01

    Full Text Available The aim of the present study was to describe the association of positive flow cross match (FXM and C1q-SAB. Methods. In this observational, cross-sectional, and comparative study, patients included had negative AHG-CDC-XM and donor specific antibodies (DSA and were tested with FXM. All pretransplant sera were tested with C1q-SAB assay. Results. A total of 50 donor/recipient evaluations were conducted; half of them had at least one C1q+ Ab (n=26, 52%. Ten patients (20.0% had DSA C1q+ Ab. Twenty-five (50% FXMs were positive. Factors associated with a positive FXM were the presence of C1q+ Ab (DSA C1q+ Ab: OR 27, 2.80–259.56, P=0.004, and no DSA C1q+ Ab: OR 5, 1.27–19.68, P=0.021 and the DSA LABScreen-SAB MFI (OR 1.26, 95% CI 1.06–1.49, P=0.007. The cutoff point of immunodominant LABScreen SAB DSA-MFI with the greatest sensitivity and specificity to predict FXM was 2,300 (sensitivity: 72% and specificity: 75%. For FXM prediction, DSA C1q+ Ab was the most specific (95.8%, 85–100 and the combination of DSA-MFI > 2,300 and C1q+ Ab was the most sensitive (92.0%, 79.3–100. Conclusions. C1q+ Ab and LABScreen SAB DSA-MFI were significantly associated with FXM. DSA C1q+ Ab was highly specific but with low sensitivity.

  3. Diagnosis of carotid body tumor by digital subtraction angiography

    Institute of Scientific and Technical Information of China (English)

    戚跃勇; 邹利光; 孙清荣; 徐健; 周政; 谭颖徽

    2004-01-01

    Objective: To make a further understanding of the features of the carotid body tumor (CBT) by digital subtraction angiography (DSA) so as to explore the clinical value of DSA diagnosis and interventional therapy for CBT. Methods: DSA data from 12 cases of CBT were analyzed retrospectively. A consensus interpretation of the DSA appearances in all of the patients was reached after dynamic observation by 2 experienced radiologists in a double-blind manner. Results: Definite diagnosis in all cases could be made by DSA. The DSA features of the CBT included bigger bifurcation angles of the internal and external carotid arteries, displacement of internal and external carotid arteries, CBT supplied by external carotid arteries in most cases and the significant increase of tumor blood vessels in bifurcation. Invasion of internal or external carotid arteries was found in 6 cases. Smaller stained area of the tumor and significantly reduced intraoperative bleeding were found after embolization of the supplying arteria in 2 cases. Conclusion: DSA is the effective method for the diagnosis and preoperative assessment of CBT. Preoperative embolization of CBT may contribute to the reduced intraoperative bleeding.

  4. Birth Control Methods

    Science.gov (United States)

    ... Home A-Z Health Topics Birth control methods Birth control methods > A-Z Health Topics Birth control methods ... To receive Publications email updates Enter email Submit Birth control methods Birth control (contraception) is any method, medicine, ...

  5. The clinical method and the scientific method

    Directory of Open Access Journals (Sweden)

    José Arteaga Herrera

    2010-12-01

    Full Text Available This paper is the chapter dedicated to the scientific method and the clinical method in the authors’ Handbook “Teaching of Clinics”. Philosophycal principles of the scientific method and its stages are presented as well as the clinical method as a scientific one and its stages. A relationship between the clinical method and the medical record is established, the role of technology in the clinical method is stated and the most frequent mistakes when applying it in clinical practice are provided. Finally, the teaching of the clinical method and the appropriate settings to do it are discussed.

  6. FY1998 survey on IEA international cooperation project on demonstration and survey of new load leveling methods (participation in the IEA/DSM task VI); 1998 nendo fuka heijunka shinshuho jissho chosa IEA kokusai kyoryoku jigyo 'IEA/DSM task 6 eno sanka ni tsuite' chosa hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-01

    It is intended to participate in the IEA international cooperation project related to DSA, exchange items of information, and promote demonstration and survey of new load leveling methods. The existing and newly proposed DSM mechanisms as the achievement of the previous tasks were put into order. The arena of information exchange and discussions was prepared through use of the Internet homepage for the IEA/DSM implementation agreement. Necessary official policies were also made available. Points of precautions when the mechanisms of other countries are used in Japan: the key to the success depends on social or cultural situations that work as the base; therefore, comparisons and analyses are necessary on such elements as customers as the object, energy projects and governments; compatibility of the situation and pattern of the demand side with the DSM technologies governs the reasonability thereof; the types of the mechanisms are narrowed down by size of the customer division, consumption pattern, electric power quality and safety, and needs on the flexibility; proliferation levels of the DSM technologies determine the appropriate mechanisms; and how the DSM is conceived against the final consumption is governed by the conception by both of the customers and the government. (NEDO)

  7. Time-of-flight MR angiography at 3 T versus digital subtraction angiography in the imaging follow-up of 51 intracranial aneurysms treated with coils

    Energy Technology Data Exchange (ETDEWEB)

    Ferre, Jean-Christophe [Department of Neuroradiology, Hopital Pontchaillou, University Hospital Rennes, 2 rue Henri Le Guilloux, 35000 Rennes (France)], E-mail: jean-christophe.ferre@chu-rennes.fr; Carsin-Nicol, Beatrice [Department of Neuroradiology, Hopital Pontchaillou, University Hospital Rennes, 2 rue Henri Le Guilloux, 35000 Rennes (France); Morandi, Xavier [Department of Neurosurgery, Hopital Pontchaillou, University Hospital Rennes, 2 rue Henri Le Guilloux, 35000 Rennes (France); Carsin, Michel [Department of Neuroradiology, Hopital Pontchaillou, University Hospital Rennes, 2 rue Henri Le Guilloux, 35000 Rennes (France); Kersaint-Gilly, Axel de [Department of Neuroradiology, Hopital Laennec, University Hospital Nantes, Boulevard Jacques Monod, 44800 Saint-Herblain (France); Gauvrit, Jean-Yves [Department of Neuroradiology, Hopital Pontchaillou, University Hospital Rennes, 2 rue Henri Le Guilloux, 35000 Rennes (France); Desal, Hubert-Armand [Department of Neuroradiology, Hopital Laennec, University Hospital Nantes, Boulevard Jacques Monod, 44800 Saint-Herblain (France)

    2009-12-15

    Objective: To compare 3D time-of-flight MR angiography (TOF-MRA) at 3 Tesla (3 T) with digital subtraction angiography (DSA) for the evaluation of intracranial aneurysm occlusion after endovascular coiling. Methods: In a prospective study, 51 consecutive patients (25 females, 26 males; median age, 51 years) with 51 saccular aneurysms treated with endovascular coiling underwent simultaneous DSA and 3 T TOF-MRA at follow-up. DSA and TOF-MRA images were analyzed independently by two senior neuroradiologists. Findings were assigned to 1 of 3 categories in the Raymond classification: complete obliteration, residual neck or residual aneurysm. Agreement between observers and techniques was evaluated using {kappa} statistics. Results: DSA images were not interpretable for one patient. Interobserver agreement was determined as excellent for DSA ({kappa} = 0.86) and TOF-MRA ({kappa} = 0.80). After reaching a consensus, DSA follow-up showed 26 (51%) complete obliterations, 20 (39%) residual necks and 4 (8%) residual aneurysms. TOF-MRA showed 23 (45%) complete obliterations, 22 (43%) residual necks and 6 (12%) residual aneurysms. Comparison between TOF-MRA and DSA showed excellent agreement between the techniques ({kappa} = 0.86). In the four cases that were misclassified, TOF-MRA findings were assigned to a higher class than for DSA. Conclusion: TOF-MRA at 3 T is at least as efficient as DSA for the evaluation of intracranial aneurysm occlusion after endovascular treatment with detachable coils. We suggest that TOF-MRA at 3 T might be used as the primary method for imaging follow-up of coiled intracranial aneurysms.

  8. Comparison of 16-row multislice CT angiography with conventional angiography for detection and evaluation of intracranial aneurysms

    Energy Technology Data Exchange (ETDEWEB)

    Donmez, Halil; Serifov, Elman; Kahriman, Guven [University of Erciyes, School of Medicine, Department of Radiology, Kayseri (Turkey); Mavili, Ertugrul, E-mail: ertmavili@yahoo.com [University of Erciyes, School of Medicine, Department of Radiology, Kayseri (Turkey); Durak, Ahmet Candan [University of Erciyes, School of Medicine, Department of Radiology, Kayseri (Turkey); Menkue, Ahmet [University of Erciyes, School of Medicine, Department of Neurosurgery, Kayseri (Turkey)

    2011-11-15

    Purpose: The aim of this study is to compare the diagnostic performance of 16-row computed tomographic angiography (MDCTA) with digital subtraction angiography (DSA) for the detection and characterization of intracranial aneurysms in patients with nontraumatic subarachnoid hemorrhages (SAH). Materials and methods: One-hundred and twelve consecutive patients with suspected intracranial aneurysm underwent both 16-row MDCTA and DSA. The MDCT angiograms were interpreted in a blinded fashion by using combination with VRI, MIP and MPR techniques. Sensitivity specificity and accuracy were calculated for the CTA and DSA. The results were compared with each other. The DSA reader's interpretation was accepted as the reference standard. Results: A total of 164 aneurysms were detected at DSA in 112 patients, no aneurysms were detected by DSA and MDCTA in 16 patients. Eight aneurysms were missed by MDCTA. The overall sensitivity, specificity, and accuracy of MDCTA on a per-aneurysm basis were 95.1%, 94.1%, and 95%, respectively. According to the size of the aneurysm less than 3 mm; sensitivity, specificity and diagnostic accuracy of MDCTA were 86.1%, 94.1%, 88.6%, respectively. Conclusion: This study suggests that MDCTA is equally as sensitive as DSA in the detection of intracranial aneurysms of greater than 3 mm, and it also reveals 100% detection rate for ruptured aneurysms.

  9. Inter- and intra-rater agreement in the assessment of the vascularity of spinal metastases using digital subtraction angiography tumor blush

    DEFF Research Database (Denmark)

    Clausen, Caroline; Dahl, Benny; Christiansen Frevert, Susanne;

    2016-01-01

    Background: Preoperative embolization is based on the preoperative digital subtraction angiography (DSA) tumor blush, and as such is considered the “gold standard” for determining tumor vascularity. However, to our knowledge reliability studies evaluating vascularity ratings of DSA tumor blush...... in spinal metastases have not been published previously. Purpose: To evaluate inter- and intra-rater agreement in the assessment of the vascularity of spinal metastases using DSA tumor blush. Material and Methods: This reliability study included 46 patients with symptomatic metastatic spinal cord...

  10. Spinal angioma demonstration using the DVI-2 system

    Energy Technology Data Exchange (ETDEWEB)

    Becker, H.; Vogelsang, H.

    1984-01-01

    If the myelogramme suggests a pathological vessel structure, intravenous digital substraction angiography (DSA) can be used for screening. However, spinal angiomas without large-volume vessels and slow contrast medium flow may elude detection. We think DSA to be a particularly valuable method in terms of follow-up after embolization or operation of spinal angiomas in order to check therapeutic success. However, intravenous DSA does not allow identification of the arteries supplying the angioma. Spinal arteriography continues to be required for any planning of operation or embolization.

  11. Diagnosis of a perforating aneurysm of the aorta as late complication of patch aortoplasty by central venous DSA

    Energy Technology Data Exchange (ETDEWEB)

    Zitzmann, A.; Kreuzer, E.; Huber, R.M.; Kenn, R.W.; Pfeifer, K.J.

    1988-06-01

    11 years after patch aortoplasty due to coarctation of the aorta a 33 year-old-patient experienced two spontaneous haemoptyses. A centralvenous digital subtraction angiography demonstrated a large aneurysm of the proximal descending aorta penetrating the left upper lobe of the lung. The successful emergency surgical treatment consisted of implantation of a dacron-prothesis.

  12. Feasibility of magnetic resonance angiography (MRA) follow-up as the primary imaging modality after coiling of intracranial aneurysms

    Energy Technology Data Exchange (ETDEWEB)

    Bakker, Nicolaas A.; Metzemaekers, Jan D. M.; Dijk, J. Marc C. van; Mooij, Jan Jakob A.; Groen, Rob J. M. (Dept. of Neurosurgery, Univ. Medical Center Groningen, Univ. of Groningen, Groningen (Netherlands)), e-mail: r.j.m.groen@nchir.umcg.nl; Westerlaan, Henriette E.; Eshghi, Omid S. (Dept. of Radiology, Univ. Medical Center Groningen, Univ. of Groningen, Groningen (Netherlands))

    2010-03-15

    Background: Digital subtraction angiography (DSA) is still regarded as the gold standard for detecting residual flow in treated aneurysms. Recent reports have also shown excellent results from magnetic resonance angiography (MRA) imaging. This is an important observation, since DSA is associated with a risk of medical complications, is time consuming, and is more expensive. Purpose: To determine whether MRA could replace conventional DSA and serve as the primary postinterventional imaging modality in patients with coiled intracranial aneurysms. Material and Methods: We studied a prospectively enrolled cohort of 190 patients treated endovascularly for a first-ruptured and/or unruptured intracranial aneurysm between January 2004 and December 2008. The imaging protocol included a 1.5T time-of-flight (TOF) MRA and a DSA at 3 months (on the same day) and, depending on comparability, a 1.5T TOF-MRA or DSA 1 year after treatment. All images were evaluated by a multidisciplinary panel. Results: In 141/190 patients, both an MRA and DSA were performed after 3-month follow-up. In 2/141 patients (1.4%), (small) neck remnants gave false-negative MRA results. In one patient (0.7%), this led to additional neurosurgical clipping of the aneurysm. In 25/141 patients, future follow-up (>3 months) consisted of DSA because of various reasons. In 24/25 of these patients, primary MRA images alone would invariably have led to additional DSA imaging. Conclusion: The present study shows that 1.5T TOF-MRA is a feasible primary follow-up modality after coiling of intracranial aneurysms. Given our data, we now suggest that, in every patient with a coiled intracranial aneurysm, the first follow-up, 3 months after coiling, should be an MRA study. Only when this MRA is inconclusive (e.g., because of coil artifacts), or in the case of suspicion of recanalization, should DSA be performed additionally

  13. Four-dimensional computed tomography angiographic evaluation of cranial dural arteriovenous fistula before and after embolization

    Energy Technology Data Exchange (ETDEWEB)

    Tian, Bing, E-mail: bing.tian@hotmail.com; Xu, Bing, E-mail: aishanli0102@126.com; Lu, Jianping, E-mail: tianbing2003@163.com; Liu, Qi, E-mail: liuqimd@126.com; Wang, Li, E-mail: wangli_changhai@163.com; Wang, Minjie, E-mail: cjr.wangminjie@vip.163.com

    2015-06-15

    Highlights: • 4D CTA showed excellent agreement with DSA with regard to identification of feeding arteries and drainage veins. • The most important finding was 4D CTA in determining the impact of DAVF treatment with transarterial embolization. • 4D CTA provides images similar to those obtained with DSA both before and after treatment. - Abstract: Purpose: This study aimed to evaluate the usefulness of four-dimensional CTA before and after embolization treatment with ONYX-18 in eleven patients with cranial dural arteriovenous fistulas, and to compare the results with those of the reference standard DSA. Patients and Methods: Eleven patients with cranial dural arteriovenous fistulas detected on DSA underwent transarterial embolization with ONYX-18. Four-dimensional CTA was performed an average of 2 days before and 4 days after DSA. Four-dimensional CTA and DSA images were reviewed by two neuroradiologists for identification of feeding arteries and drainage veins and for determining treatment effects. Interobserver and intermodality agreement between four-dimensional CTA and DSA were assessed. Results: Forty-two feeding arteries were identified for 14 fistulas in the 11 patients. Of these, 36 (85.71%) were detected on four-dimensional CTA. After transarterial embolization, one patient got partly embolized, and the fistulas in the remaining 10 patients were completely occluded. The interobserver agreement for four-dimensional CTA and intermodality agreement between four-dimensional CTA and DSA were excellent (κ = 1) for shunt location, identification of drainage veins, and fistula occlusion after treatment. Conclusion: Four-dimensional CTA images are highly accurate when compared with DSA images both before and after transarterial embolization treatment. Four-dimensional CTA can be used for diagnosis as well as follow-up of cranial dural arteriovenous fistulas in clinical settings.

  14. Rapid Measurement of Food Adulteration with Minimal Sample Preparation and No Chromatography Using Ambient Ionization Mass Spectrometry.

    Science.gov (United States)

    Dalmia, Avinash

    2017-03-01

    A rapid method, with minimal sample preparation and no chromatography, was developed for analyzing food samples such as olive oil and pomegranate juice to measure adulteration with cheaper ingredients using the novel Direct Sample Analysis™ (DSA) ion source in conjunction with a time-of-flight (TOF)-MS. In less than 30 s, with minimal sample preparation and method development, adulteration of olive oil and pomegranate juice with cheaper seed oils and fruit juices, respectively, was measured with DSA/TOF-MS.

  15. An Inexact Halley's Method

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    An inexact Halley's method-Halley-PCG(preconditioned conjugate gradient) method is proposed for solving the systems of linear equations for improved Halley method either by Cholesky factorization exactly or by preconditioned conjugate gradient method approximately. The convergence result is given and the efficiency of the method compared to the improved Halley's method is shown.

  16. M-AMST: an automatic 3D neuron tracing method based on mean shift and adapted minimum spanning tree.

    Science.gov (United States)

    Wan, Zhijiang; He, Yishan; Hao, Ming; Yang, Jian; Zhong, Ning

    2017-03-29

    Understanding the working mechanism of the brain is one of the grandest challenges for modern science. Toward this end, the BigNeuron project was launched to gather a worldwide community to establish a big data resource and a set of the state-of-the-art of single neuron reconstruction algorithms. Many groups contributed their own algorithms for the project, including our mean shift and minimum spanning tree (M-MST). Although M-MST is intuitive and easy to implement, the MST just considers spatial information of single neuron and ignores the shape information, which might lead to less precise connections between some neuron segments. In this paper, we propose an improved algorithm, namely M-AMST, in which a rotating sphere model based on coordinate transformation is used to improve the weight calculation method in M-MST. Two experiments are designed to illustrate the effect of adapted minimum spanning tree algorithm and the adoptability of M-AMST in reconstructing variety of neuron image datasets respectively. In the experiment 1, taking the reconstruction of APP2 as reference, we produce the four difference scores (entire structure average (ESA), different structure average (DSA), percentage of different structure (PDS) and max distance of neurons' nodes (MDNN)) by comparing the neuron reconstruction of the APP2 and the other 5 competing algorithm. The result shows that M-AMST gets lower difference scores than M-MST in ESA, PDS and MDNN. Meanwhile, M-AMST is better than N-MST in ESA and MDNN. It indicates that utilizing the adapted minimum spanning tree algorithm which took the shape information of neuron into account can achieve better neuron reconstructions. In the experiment 2, 7 neuron image datasets are reconstructed and the four difference scores are calculated by comparing the gold standard reconstruction and the reconstructions produced by 6 competing algorithms. Comparing the four difference scores of M-AMST and the other 5 algorithm, we can conclude that

  17. The value of three-dimension digital subtraction angiography in cerebro-vascular diseases%3D-DSA在脑血管疾病诊断中的应用价值

    Institute of Scientific and Technical Information of China (English)

    刘康; 缪南东; 任勇军; 徐浩; 闵旭立; 杨林; 张小明

    2015-01-01

    Objective:To study the value of three-dimension digital subtraction angiography (3D-DSA) in cerebrovascular dis-eases. Methods:A retrospective analysis of 208 patients who underwent both 2D-DSA and 3D-DSA for evaluation of previously untreat-ed cerebrovascular diseases was conducted. The data of 2D-DSA and 3D-DSA images were analyzed. Results:Among the 208 patients, there are 128 patients with artery aneurysm,and 29 with artery stenosis or obstruction,22 with AVM,10 with moyamoya disease and 4 intracranial tumors. The detection rate of 2D-DSA is 80. 3%,while the rate of 3D-DSA is 92. 8%. This difference was significant in sta-tistics ( P< 0. 05 ) . Conclusion:Three-dimension DSA plays an important role in diagnosis and treatment of cerebrovascular diseases, and is an optimized and complemental imaging technique of 2D-DSA.%目的::探讨三维数字减影血管造影(three-dimension digital subtraction angiography,3D-DSA)在脑血管疾病诊断中的应用价值。方法:对临床怀疑脑血管疾病患者208例,同时进行常规DSA(2D-DSA)和3D-DSA检查,并对结果进行对比分析。结果:208例中,检出动脉瘤128例,脑动脉狭窄或闭塞29例,动静脉畸22例,烟雾病10例,脑肿瘤4例。2D-DSA病变检出率80.3%(167/208);3D-DSA病变检出率92.8%(193/208);两组检出率差异具有统计学意义(P<0.05)。结论:3D-DSA在脑血管疾病诊断中具有重要的应用价值,是2D-DSA的优化和补充。

  18. Meshless Methods Coupled with Other Numerical Methods

    Institute of Scientific and Technical Information of China (English)

    Y.T.GU; G.R.LIU

    2005-01-01

    Meshless or mesh-free (or shorten as MFree) methods have been proposed and achieved remarkable progress over the past few years. The idea of combining MFree methods with other existing numerical techniques such as the finite element method (FEM) and the boundary element method (BEM), is naturally of great interest in many practical applications. However, the shape functions used in some MFree methods do not have the Kronecker delta function property. In order to satisfy the combined conditions of displacement compatibility, two numerical techniques, using the hybrid displacement shape function and the modified variational form, are developed and discussed in this paper. In the first technique, the original MFree shape functions are modified to the hybrid forms that possess the Kronecker delta function property. In the second technique, the displacement compatibility is satisfied via a modified variational form based on the Lagrange multiplier method. Formulations of several coupled methods are presented. Numerical examples are presented to demonstrate the effectiveness of the present coupling methods.

  19. From Method to Post Method: A Panacea!

    Science.gov (United States)

    Masouleh, Nima Shakouri

    2012-01-01

    The foundation of language teaching has undergone many changes. The rise and fall of language teaching methods depends upon a variety of factors extrinsic to a method itself and often reflects the influence of profit-seekers and promoters, as well as the forces of the intellectual marketplace. There was always a source of contention among people…

  20. The Multidimensional WKB Method.

    Science.gov (United States)

    Knudson, Stephen K.; Noid, D. W.

    1989-01-01

    Discusses a new method for determining the eigenvalues of the Schroedinger equation when the potential energy function does not have a simple form. Describes the mathematical methods and provides an application. Lists limitations to the method. (MVL)

  1. ANALYSIS OF MULTISCALE METHODS

    Institute of Scientific and Technical Information of China (English)

    Wei-nan E; Ping-bing Ming

    2004-01-01

    The heterogeneous multiscale method gives a general framework for the analysis of multiscale methods. In this paper, we demonstrate this by applying this framework to two canonical problems: The elliptic problem with multiscale coefficients and the quasicontinuum method.

  2. Ensemble Data Mining Methods

    Data.gov (United States)

    National Aeronautics and Space Administration — Ensemble Data Mining Methods, also known as Committee Methods or Model Combiners, are machine learning methods that leverage the power of multiple models to achieve...

  3. Simplifications of CQC method and CCQC method

    Institute of Scientific and Technical Information of China (English)

    Yu Ruifang; Zhou Xiyuan

    2007-01-01

    The response-spectrum mode superposition method is widely used for seismic response analyses of linear systems. In using this method, the complete quadratic combination (CQC) is adopted for classically damped linear systems and the complex complete quadratic combination (CCQC) formula is adopted for non-classically damped linear systems.However, in both cases, the calculation of seismic response analyses is very time consuming. In this paper, the variation of the modal correlation coefficients of displacement, velocity and displacement-velocity with frequency and damping ratios of two modes of interest are studied, Moreover, the calculation errors generated by using CQC and square-root-of-the-sum-of-the-squares (SRSS) methods (or CCQC and CSRSS methods) for different damping combinations are compared. In these analyses,some boundary lines for classically and non-classically damped systems are plotted to distinguish the allowed minimum frequency ratio at given geometric mean of the damping ratios of both modes if their relativity is neglected. Furthermore,the simplified method, which is a special mode quadratic combination method considering only relativity of adjacent modes in CQC method and named simplified CQC or partial quadratic combination (PQC) method for classically damped linear system, is proposed to improve computational efficiency, and the criterion for determination of how many correlated modes should be adopted is proposed. Similarly, the simplified CCQC or complex partial quadratic combination (CPQC) method for the non-classically damped linear system and the corresponding criterion are also deduced. Finally, a numerical example is given to illustrate the applicability, computational accuracy and efficiency of the PQC and CPQC methods.

  4. Super-Selective Mesenteric Embolization Provides Effective Control of Lower GI Bleeding

    OpenAIRE

    Toan Pham; Bob Anh Tran; Kevin Ooi; Marcus Mykytowycz; Stephen McLaughlin; Matthew Croxford; Iain Skinner; Ian Faragher

    2017-01-01

    Introduction. We aimed to assess the efficacy and safety of digital subtraction angiography (DSA) and super-selective mesenteric artery embolization (SMAE) in managing lower GI bleeding (LGIB). Method. A retrospective case series of patients with LGIB treated with SMAE in our health service. Patients with confirmed active LGIB, on either radionuclide scintigraphy (RS) or contrast-enhanced multidetector CT angiography (CE-MDCT), were referred for DSA +/− SMAE. Data collected included patient c...

  5. Clinical value of three-dimensional digital subtraction angiography in the endovascular treatment of intracranial aneurysms

    Institute of Scientific and Technical Information of China (English)

    Tianxiao Li; Dengwei Zong

    2006-01-01

    BACKGROUND: The endovascular treatment of intracranial aneurysms requires clearly displayed anatomic structures of the aneurysm and the reference image of the aneurysm neck, the images of the form and struc ture of the aneurysm and the three-dimensional (3D) intracranial vascular structure are very important for the diagnosis and treatment of cerebral aneurysms. OBJECTIVE: To investigate the value of 3D digital subtraction angiography (3D DSA) in diagnosing intracra nial aneurysm, and compare the reliability with two-dimensional (2D) DSA in evaluating the intracranial aneurysm suitable for the endovascular occlusion: DESIGN: A double-blind case observation. SETTING: Department of Interventional Radiology, Henan People's Hospital. PARTICIPANTS: The patients, who were suspected to have intracranial aneurysms, were examined with 2D DSA and 3D DSA in Henan People's Hospital from October 2004 to October 2005. Fifty intracranial aneurysms were detected in 44 patients (19 males and 25 females) of 30-75 years, with an average of 51 years, including 5 cases were multiple aneurysms, including 2 aneurysms in 4 cases and 3 aneurysms in 1 case. The aneurysms located respectively at internal carotid artery (n =19), anterior cerebral artery (n =16), middle cerebral artery (n =8), basilar artery (n =6), and posterior inferior cerebellar artery (n =1 ). METHODS: The 50 ruptured intracranial aneurysms were examined with 2D DSA and 3D DSA. The method of volume reconstruction was applied to reconstruct the 3D DSA images, and the automatically generated images could be shifted, rotated and magnified, besides, the corresponding processing could also be performed, including resecting the unnecessary structure and sharpening margin of the images. Observations: ① Display of aneurysm neck: The site and range of the aneurysm neck, and the involvement of branches originated from the aneurysm arteries; ② Display of aneurysm form: The displays of aneurysm form and with or without arteries

  6. Simulations using meshfree methods

    CERN Document Server

    P, Kirana Kumara

    2015-01-01

    In this paper, attempt is made to solve a few problems using the Polynomial Point Collocation Method (PPCM), the Radial Point Collocation Method (RPCM), Smoothed Particle Hydrodynamics (SPH), and the Finite Point Method (FPM). A few observations on the accuracy of these methods are recorded. All the simulations in this paper are three dimensional linear elastostatic simulations, without accounting for body forces.

  7. The use of neurovascular ultrasound versus digital subtraction angiography in acute ischemic stroke

    Directory of Open Access Journals (Sweden)

    Marcos C. Lange

    2015-03-01

    Full Text Available Cervical and intracranial arterial evaluation is an important issue for acute ischemic stroke (IS. Objective Compare the use of the neurovascular ultrasound examination (NVUE to digital subtraction angiography (DSA in acute IS patients for diagnosing significant extracranial and intracranial arteriopathy. Method Nonconsecutive patients with IS or transient ischemic attack admitted within 12 hours of the onset of symptoms were evaluated retrospectively. Standardized NVUE and DSA were done in all patients within the first 120 hours of hospital admission. Results Twenty-four patients were included in the study. Compared to DSA, the NVUE demonstrated 94.7% sensitivity and 100% specificity for identifying symptomatic extracranial and/or intracranial arteriopathy. Conclusion The standardized NVUE technique demonstrated high sensitivity and specificity compared to DSA for diagnosing arterial abnormalities in acute IS patients.

  8. Numerical Methods for Multilattices

    CERN Document Server

    Abdulle, Assyr; Shapeev, Alexander V

    2011-01-01

    Among the efficient numerical methods based on atomistic models, the quasicontinuum (QC) method has attracted growing interest in recent years. The QC method was first developed for crystalline materials with Bravais lattice and was later extended to multilattices (Tadmor et al, 1999). Another existing numerical approach to modeling multilattices is homogenization. In the present paper we review the existing numerical methods for multilattices and propose another concurrent macro-to-micro method in the homogenization framework. We give a unified mathematical formulation of the new and the existing methods and show their equivalence. We then consider extensions of the proposed method to time-dependent problems and to random materials.

  9. Inflow Turbulence Generation Methods

    Science.gov (United States)

    Wu, Xiaohua

    2017-01-01

    Research activities on inflow turbulence generation methods have been vigorous over the past quarter century, accompanying advances in eddy-resolving computations of spatially developing turbulent flows with direct numerical simulation, large-eddy simulation (LES), and hybrid Reynolds-averaged Navier-Stokes–LES. The weak recycling method, rooted in scaling arguments on the canonical incompressible boundary layer, has been applied to supersonic boundary layer, rough surface boundary layer, and microscale urban canopy LES coupled with mesoscale numerical weather forecasting. Synthetic methods, originating from analytical approximation to homogeneous isotropic turbulence, have branched out into several robust methods, including the synthetic random Fourier method, synthetic digital filtering method, synthetic coherent eddy method, and synthetic volume forcing method. This article reviews major progress in inflow turbulence generation methods with an emphasis on fundamental ideas, key milestones, representative applications, and critical issues. Directions for future research in the field are also highlighted.

  10. Advanced differential quadrature methods

    CERN Document Server

    Zong, Zhi

    2009-01-01

    Modern Tools to Perform Numerical DifferentiationThe original direct differential quadrature (DQ) method has been known to fail for problems with strong nonlinearity and material discontinuity as well as for problems involving singularity, irregularity, and multiple scales. But now researchers in applied mathematics, computational mechanics, and engineering have developed a range of innovative DQ-based methods to overcome these shortcomings. Advanced Differential Quadrature Methods explores new DQ methods and uses these methods to solve problems beyond the capabilities of the direct DQ method.After a basic introduction to the direct DQ method, the book presents a number of DQ methods, including complex DQ, triangular DQ, multi-scale DQ, variable order DQ, multi-domain DQ, and localized DQ. It also provides a mathematical compendium that summarizes Gauss elimination, the Runge-Kutta method, complex analysis, and more. The final chapter contains three codes written in the FORTRAN language, enabling readers to q...

  11. Consumer Behavior Research Methods

    DEFF Research Database (Denmark)

    Chrysochou, Polymeros

    2017-01-01

    emphasizes the discussion of primary research methods. Based on the nature of the data primary research methods are further distinguished into qualitative and quantitative. The chapter describes the most important and popular qualitative and quantitative methods. It concludes with an overall evaluation......This chapter starts by distinguishing consumer behavior research methods based on the type of data used, being either secondary or primary. Most consumer behavior research studies phenomena that require researchers to enter the field and collect data on their own, and therefore the chapter...... of the methods and how to improve quality in consumer behavior research methods....

  12. Theoretical and experimental comparison of image signal and noise for dual-energy subtraction angiography and conventional x-ray angiography

    Science.gov (United States)

    Burton, Christiane S.; Mayo, John R.; Cunningham, I. A.

    2015-03-01

    Cardiovascular disease is currently the leading cause of mortality worldwide. Digital subtraction angiography (DSA) is widely used to enhance the visibility of small vessels and vasculature obscurred by overlying bone and lung fields by subtracting a mask and contrast image. However, motion between these mask and contrast images can introduce artifacts that can render a study non-diagnostic. This makes DSA particularly unsuccessful for cardiac imaging. A method called dual-energy, or energy subtraction angiography (ESA), was proposed in the past as an alternative for vascular imaging, however it was not pursued because experimental results suggested that image quality was deemed as poor and inferior to DSA. Image quality for angiography comes down to iodine signal and noise. In this paper we investigate the fundamental iodine signal and noise analysis of ESA and compare it to DSA. Method: We developed a polyenergetic and monoenergetic theoretical model for iodine signal and noise for both ESA and DSA. We validated our polyenergetic model by experiment where ESA and DSA images of a vascular phantom were acquired using an x-ray system with a flat panel CsI Xmaru1215CF-MPTM (Rayence Co., Ltd., Republic of Korea) detector. For ESA low and high applied tube voltages of 50 kV and 120 kV (2.5 mmCu), respectively, and for DSA the applied tube voltage was 80 kV. Iodine signal-to-noise ratio (SNR) per entrance exposure was calculated for each iodine concentration for both ESA and DSA. Results: Our measured iodine SNR agreed well with theoretical calculations. Iodine SNR for ESA was relatively higher than DSA for low iodine mass loadings, and as iodine mass loading increases iodine SNR decreases. Conclusions: We have developed a model for iodine SNR for both DSA and ESA. Our model was validated with experiment and showed excellent agreement. We have shown that there is potential for obtaining iodine-specific images using ESA that are similar to DSA.

  13. Quality Control Analytical Methods: Method Validation.

    Science.gov (United States)

    Klang, Mark G; Williams, LaVonn A

    2016-01-01

    To properly determine the accuracy of a pharmaceutical product or compounded preparation, tests must be designed specifically for that evaluation. The procedures selected must be verified through a process referred to as method validation, an integral part of any good analytical practice. The results from a method validation procedure can be used to judge the quality, reliability, and consistency of analytical results. The purpose of this article is to deliver the message of the importance of validation of a pharmaceutical product or compounded preparation and to briefly discuss the results of a lack of such validation. Copyright© by International Journal of Pharmaceutical Compounding, Inc.

  14. Standardized Volume Rendering for Magnetic Resonance Angiography Measurements in the Abdominal Aorta

    Energy Technology Data Exchange (ETDEWEB)

    Persson, A.; Brismar, T.B.; Lundstroem, C.; Dahlstroem, N.; Othberg, F.; Smedby, Oe. [Linkoeping Univ. Hospital (Sweden). Center for Medical Image Science and Visualization (CMIV)

    2006-03-15

    Purpose: To compare three methods for standardizing volume rendering technique (VRT) protocols by studying aortic diameter measurements in magnetic resonance angiography (MRA) datasets. Material and Methods: Datasets from 20 patients previously examined with gadolinium-enhanced MRA and with digital subtraction angiography (DSA) for abdominal aortic aneurysm were retrospectively evaluated by three independent readers. The MRA datasets were viewed using VRT with three different standardized transfer functions: the percentile method (Pc-VRT), the maximum-likelihood method (ML-VRT), and the partial range histogram method (PRH-VRT). The aortic diameters obtained with these three methods were compared with freely chosen VRT parameters (F-VRT) and with maximum intensity projection (MIP) concerning inter-reader variability and agreement with the reference method DSA. Results: F-VRT parameters and PRH-VRT gave significantly higher diameter values than DSA, whereas Pc-VRT gave significantly lower values than DSA. The highest interobserver variability was found for F-VRT parameters and MIP, and the lowest for Pc-VRT and PRH-VRT. All standardized VRT methods were significantly superior to both MIP and F-VRT in this respect. The agreement with DSA was best for PRH-VRT, which was the only method with a mean error below 1 mm and which also had the narrowest limits of agreement (95% of cases between 2.1 mm below and 3.1 mm above DSA). Conclusion: All the standardized VRT methods compare favorably with MIP and VRT with freely selected parameters as regards interobserver variability. The partial range histogram method, although systematically overestimating vessel diameters, gives results closest to those of DSA.

  15. Applied Bayesian Hierarchical Methods

    CERN Document Server

    Congdon, Peter D

    2010-01-01

    Bayesian methods facilitate the analysis of complex models and data structures. Emphasizing data applications, alternative modeling specifications, and computer implementation, this book provides a practical overview of methods for Bayesian analysis of hierarchical models.

  16. Dissolution Methods Database

    Data.gov (United States)

    U.S. Department of Health & Human Services — For a drug product that does not have a dissolution test method in the United States Pharmacopeia (USP), the FDA Dissolution Methods Database provides information on...

  17. Dissolution Methods Database

    Data.gov (United States)

    U.S. Department of Health & Human Services — For a drug product that does not have a dissolution test method in the United States Pharmacopeia (USP), the FDA Dissolution Methods Database provides information on...

  18. Simulated floating zone method

    OpenAIRE

    Ozawa, Ryo; Kato, Yasuyuki; Motome, Yukitoshi

    2016-01-01

    This paper provides the simulated floating zone (SFZ) method that is an efficient simulation technique to obtain thermal equilibrium states, especially useful when domain formation prevents the system from reaching a spatially-uniform stable state. In the SFZ method, the system is heated up locally, and the heated region is steadily shifted, similar to the floating zone method for growing a single crystal with less lattice defect and impurity in experiments. We demonstrate that the SFZ method...

  19. Mixed methods research.

    Science.gov (United States)

    Halcomb, Elizabeth; Hickman, Louise

    2015-04-08

    Mixed methods research involves the use of qualitative and quantitative data in a single research project. It represents an alternative methodological approach, combining qualitative and quantitative research approaches, which enables nurse researchers to explore complex phenomena in detail. This article provides a practical overview of mixed methods research and its application in nursing, to guide the novice researcher considering a mixed methods research project.

  20. Geobacteraceae strains and methods

    Science.gov (United States)

    Lovley, Derek R.; Nevin, Kelly P.; Yi, Hana

    2015-07-07

    Embodiments of the present invention provide a method of producing genetically modified strains of electricigenic microbes that are specifically adapted for the production of electrical current in microbial fuel cells, as well as strains produced by such methods and fuel cells using such strains. In preferred embodiments, the present invention provides genetically modified strains of Geobacter sulfurreducens and methods of using such strains.

  1. Numerical methods using Matlab

    CERN Document Server

    Gupta, Abhishek

    2015-01-01

    Numerical Methods with MATLAB provides a highly-practical reference work to assist anyone working with numerical methods. A wide range of techniques are introduced, their merits discussed and fully working MATLAB code samples supplied to demonstrate how they can be coded and applied. Numerical methods have wide applicability across many scientific, mathematical, and engineering disciplines and are most often employed in situations where working out an exact answer to the problem by another method is impractical. Numerical Methods with MATLAB presents each topic in a concise and readable

  2. The Generalized Sturmian Method

    DEFF Research Database (Denmark)

    Avery, James Emil

    2011-01-01

    generations of researchers were left to work out how to achieve this ambitious goal for molecular systems of ever-increasing size. This book focuses on non-mainstream methods to solve the molecular electronic Schrödinger equation. Each method is based on a set of core ideas and this volume aims to explain...... these ideas clearly so that they become more accessible. By bringing together these non-standard methods, the book intends to inspire graduate students, postdoctoral researchers and academics to think of novel approaches. Is there a method out there that we have not thought of yet? Can we design a new method...

  3. Mimetic discretization methods

    CERN Document Server

    Castillo, Jose E

    2013-01-01

    To help solve physical and engineering problems, mimetic or compatible algebraic discretization methods employ discrete constructs to mimic the continuous identities and theorems found in vector calculus. Mimetic Discretization Methods focuses on the recent mimetic discretization method co-developed by the first author. Based on the Castillo-Grone operators, this simple mimetic discretization method is invariably valid for spatial dimensions no greater than three. The book also presents a numerical method for obtaining corresponding discrete operators that mimic the continuum differential and

  4. Detecting hepatic nodules and identifying feeding arteries of hepatocellular carcinoma:efifcacy of cone-beam computed tomography in transcatheter arterial chemoembolization

    Institute of Scientific and Technical Information of China (English)

    Yasuhiro Ushijima; Tsuyoshi Tajima; Akihiro Nishie; Yoshiki Asayama; Kousei Ishigami; Masakazu Hirakawa; Daisuke Kakihara; Daisuke Okamoto; Hiroshi Honda

    2016-01-01

    Aim: To evaluate the effectiveness of using cone-beam computed tomography (CBCT) in transcatheter arterial chemoembolization (TACE) to detect hapatocelular carcinoma (HCC) nodules and their feeding arteries.Methods: Twenty-four patients with HCCs who underwent TACE using CBCT in addition to conventional digital subtraction angiography (DSA) were enroled. After both conventional DSA and CBCT through the hepatic artery were acquired, TACE were performed. The nodules were deifned as an HCC when dense accumulation of iodized oil was found within the nodule on CT obtained 2 weeks after the TACE. The number of detected nodules and identiifed feeding arteries, and their correlations with anatomical locations were assessed.Results: A total of 39 HCC nodules (tumor diameter, 7-40 mm; mean, 17.4 ± 7.9 mm) were detected. Thirty-one nodules were detected by DSA alone but 8 nodules were additionaly detected by adding CBCT to DSA. There were 53 feeding arteries associated with the 39 HCC nodules. Among these arteries, 21 were identiifed by DSA alone; however, 47 were identiifed by combining CBCT with DSA. Additional feeding arteries, especialy for the nodules located at the right and caudate lobes, were identiifed by CBCT. On the other hand, there was no difference in detection of nodules between the anatomical locations by CBCT.Conclusion: The use of CBCT in addition to DSA offers potential for increasing the number of detected nodules, and the number of their feeding arteries at the right and caudate lobes. CBCT might improve the quality of TACE procedure for HCC than DSA alone.

  5. Inspection of directed self-assembly defects

    Science.gov (United States)

    Ito, Chikashi; Durant, Stephane; Lange, Steve; Harukawa, Ryota; Miyagi, Takemasa; Nagaswami, Venkat; Rincon Delgadillo, Paulina; Gronheid, Roel; Nealey, Paul

    2014-03-01

    Directed Self-Assembly (DSA) is considered as a potential patterning solution for future generation devices. One of the most critical challenges for translating DSA into high volume manufacturing is to achieve low defect density in the DSA patterning process. The defect inspection capability is fundamental to defect reduction in any process, particularly the DSA process, as it provides engineers with information on the numbers and types of defects. While the challenges of other candidates of new generation lithography are well known (for example, smaller size, noise level due to LER etc.), the DSA process causes certain defects that are unique. These defects are nearly planar and in a material which produces very little defect scattering signal. These defects, termed as "dislocation" and "disclination" have unique shapes and have very little material contrast. While large clusters of these unique defects are easy to detect, single dislocation and disclination defects offer considerable challenge during inspection. In this investigation, etching the DSA pattern into a silicon (Si) substrate structure to enhance defect signal and Signal-to-Noise Ratio (SNR) is studied. We used a Rigorous Coupled-Wave Analysis (RCWA) method for solving Maxwell's equations to simulate the DSA unique defects and calculate inspection parameters. Controllable inspection parameters include various illumination and collection apertures, wavelength band, polarization, noise filtering, focus, pixel size, and signal processing. From the RCWA simulation, we compared SNR between "Post-SiN etch" and "Post-SiN+Si-substrate etch" steps. The study is also extended to investigate wafer-level data at post etch inspection. Both the simulations and inspection tool results showed dramatic signal and SNR improvements when the pattern was etched into the SiN+Si substrate allowing capture of DSA unique defect types.

  6. Methods for assessing geodiversity

    Science.gov (United States)

    Zwoliński, Zbigniew; Najwer, Alicja; Giardino, Marco

    2017-04-01

    The accepted systematics of geodiversity assessment methods will be presented in three categories: qualitative, quantitative and qualitative-quantitative. Qualitative methods are usually descriptive methods that are suited to nominal and ordinal data. Quantitative methods use a different set of parameters and indicators to determine the characteristics of geodiversity in the area being researched. Qualitative-quantitative methods are a good combination of the collection of quantitative data (i.e. digital) and cause-effect data (i.e. relational and explanatory). It seems that at the current stage of the development of geodiversity research methods, qualitative-quantitative methods are the most advanced and best assess the geodiversity of the study area. Their particular advantage is the integration of data from different sources and with different substantive content. Among the distinguishing features of the quantitative and qualitative-quantitative methods for assessing geodiversity are their wide use within geographic information systems, both at the stage of data collection and data integration, as well as numerical processing and their presentation. The unresolved problem for these methods, however, is the possibility of their validation. It seems that currently the best method of validation is direct filed confrontation. Looking to the next few years, the development of qualitative-quantitative methods connected with cognitive issues should be expected, oriented towards ontology and the Semantic Web.

  7. Design Methods in Practice

    DEFF Research Database (Denmark)

    Jensen, Torben Elgaard; Andreasen, Mogens Myrup

    2010-01-01

    The paper challenges the dominant and widespread view that a good design method will guarantee a systematic approach as well as certain results. First, it explores the substantial differences between on the one hand the conception of methods implied in Pahl & Beitz’s widely recognized text book...... subject to change; The goals of methods are less stable than assumed. The paper finally suggests that ethnomethodology and similar approaches direct our attention to the fact that method use is always a situated and socially interactive affair. It is crucial to attend to these dimensions of method use...... on engineering design, and on the other hand the understanding of method use, which has emerged from micro-sociological studies of practice (ethnomethodology). Second, it reviews a number of case studies conducted by engineering students, who were instructed to investigate the actual use of design methods...

  8. Consensus theoretic classification methods

    Science.gov (United States)

    Benediktsson, Jon A.; Swain, Philip H.

    1992-01-01

    Consensus theory is adopted as a means of classifying geographic data from multiple sources. The foundations and usefulness of different consensus theoretic methods are discussed in conjunction with pattern recognition. Weight selections for different data sources are considered and modeling of non-Gaussian data is investigated. The application of consensus theory in pattern recognition is tested on two data sets: 1) multisource remote sensing and geographic data and 2) very-high-dimensional remote sensing data. The results obtained using consensus theoretic methods are found to compare favorably with those obtained using well-known pattern recognition methods. The consensus theoretic methods can be applied in cases where the Gaussian maximum likelihood method cannot. Also, the consensus theoretic methods are computationally less demanding than the Gaussian maximum likelihood method and provide a means for weighting data sources differently.

  9. Experience with intravenous digital subtraction angiography following shunting in 4 cases of congenital heart diseases

    Energy Technology Data Exchange (ETDEWEB)

    Higashidate, Masafumi; Konno, Susumu; Sumitomo, Naokata; Ito, Sango; Kobayashi, Hiroshi

    1985-01-01

    Intravenous digital subtraction angiography (IV-DSA) was performed in two patients with Fallot's tetralogy who underwent Blalock-Taussing operation, a patient with coarctation of the aortic arch who underwent extra-anastomic bypass between the ascending aorta and the descending aorta, and a patient with stenosis of the tricuspid valve who underwent Fontan type operation (anastomosis between the right atrium and the pulmonary artery). The conventional cardiac angiography was also performed for the comparison with IV-DSA in all patients. IV-DSA revealed the thickness of the subclavian artery anastomosed by Blaloch-Taussing operation, but failed to determine the accurate thickness of the pulmonary artery required for PA-index for radical surgery in cases of Fallot's tetralogy. Bypass from the ascending aorta to the descending aorta was well visualized by IV-DSA because the heart did not overlap on the image. In cases of Fontan type operation, IV-DSA permitted the visualization of blood flow from the right atrium to the pulmonary artery and the shape of the pulmonary artery. It is concluded that IV-DSA is a less invasive, simple technique to evaluate patients' condition following shunting for congenital heart diseases, as compared to the conventional method. (Namekawa, K.).

  10. A LabVIEW Platform for Preclinical Imaging Using Digital Subtraction Angiography and Micro-CT.

    Science.gov (United States)

    Badea, Cristian T; Hedlund, Laurence W; Johnson, G Allan

    2013-01-01

    CT and digital subtraction angiography (DSA) are ubiquitous in the clinic. Their preclinical equivalents are valuable imaging methods for studying disease models and treatment. We have developed a dual source/detector X-ray imaging system that we have used for both micro-CT and DSA studies in rodents. The control of such a complex imaging system requires substantial software development for which we use the graphical language LabVIEW (National Instruments, Austin, TX, USA). This paper focuses on a LabVIEW platform that we have developed to enable anatomical and functional imaging with micro-CT and DSA. Our LabVIEW applications integrate and control all the elements of our system including a dual source/detector X-ray system, a mechanical ventilator, a physiological monitor, and a power microinjector for the vascular delivery of X-ray contrast agents. Various applications allow cardiac- and respiratory-gated acquisitions for both DSA and micro-CT studies. Our results illustrate the application of DSA for cardiopulmonary studies and vascular imaging of the liver and coronary arteries. We also show how DSA can be used for functional imaging of the kidney. Finally, the power of 4D micro-CT imaging using both prospective and retrospective gating is shown for cardiac imaging.

  11. Methods of Software Verification

    Directory of Open Access Journals (Sweden)

    R. E. Gurin

    2015-01-01

    Full Text Available This article is devoted to the problem of software verification (SW. Methods of software verification designed to check the software for compliance with the stated requirements such as correctness, system security and system adaptability to small changes in the environment, portability and compatibility, etc. These are various methods both by the operation process and by the way of achieving result. The article describes the static and dynamic methods of software verification and paid attention to the method of symbolic execution. In its review of static analysis are discussed and described the deductive method, and methods for testing the model. A relevant issue of the pros and cons of a particular method is emphasized. The article considers classification of test techniques for each method. In this paper we present and analyze the characteristics and mechanisms of the static analysis of dependencies, as well as their views, which can reduce the number of false positives in situations where the current state of the program combines two or more states obtained both in different paths of execution and in working with multiple object values. Dependences connect various types of software objects: single variables, the elements of composite variables (structure fields, array elements, the size of the heap areas, the length of lines, the number of initialized array elements in the verification code using static methods. The article pays attention to the identification of dependencies within the framework of the abstract interpretation, as well as gives an overview and analysis of the inference tools.Methods of dynamic analysis such as testing, monitoring and profiling are presented and analyzed. Also some kinds of tools are considered which can be applied to the software when using the methods of dynamic analysis. Based on the work a conclusion is drawn, which describes the most relevant problems of analysis techniques, methods of their solutions and

  12. Performative Schizoid Method

    DEFF Research Database (Denmark)

    Svabo, Connie

    2016-01-01

    A performative schizoid method is developed as a method contribution to performance as research. The method is inspired by contemporary research in the human and social sciences urging experimentation and researcher engagement with creative and artistic practice. In the article, the method...... is presented and an example is provided of a first exploratory engagement with it. The method is used in a specific project Becoming Iris, making inquiry into arts-based knowledge creation during a three month visiting scholarship at a small, independent visual art academy. Using the performative schizoid...... method in Becoming Iris results in four audio-visual and performance-based productions, centered on an emergent theme of the scholartist as a bird in borrowed feathers. Interestingly, the moral lesson of the fable about the vain jackdaw, who dresses in borrowed peacock feathers and becomes a castout...

  13. Exoplanet Detection Methods

    CERN Document Server

    Wright, Jason T

    2012-01-01

    This chapter reviews various methods of detecting planetary companions to stars from an observational perspective, focusing on radial velocities, astrometry, direct imaging, transits, and gravitational microlensing. For each method, this chapter first derives or summarizes the basic observable phenomena that are used to infer the ex- istence of planetary companions, as well as the physical properties of the planets and host stars that can be derived from the measurement of these signals. This chapter then outlines the general experimental requirements to robustly detect the signals us- ing each method, by comparing their magnitude to the typical sources of measurement uncertainty. This chapter goes on to compare the various methods to each other by outlining the regions of planet and host star parameter space where each method is most sensitive, stressing the complementarity of the ensemble of the methods at our disposal. Finally, there is a brief review of the history of the young exoplanet field, from the f...

  14. Phenomenographic Research Method

    Directory of Open Access Journals (Sweden)

    Erdem ÇEKMEZ

    2012-12-01

    Full Text Available Phenomenography, an approach to educational research, emerged from the studies carried out by Ference Marton and his colleagues at the University of Göteborg, Sweden, in the early 1970s. Phenomenography is the empirical study of the different ways in which people experience, perceive, apprehend, understand, conceptualize various phenomena in the world around them. Not only this method has been used much in educational researches in Turkey, but also the books about research methods do not provide detailed information about this method in details. This study explains the aim, characteristics, historical background and how to ensure the generalization, validity and reliability of phenomenographic research outcomes, besides mentions to the studies in which phenomenographic research method was used. In addition, the differences and similarities between this method and methods similar to phenomenology are explained.

  15. The Schwinger Variational Method

    Science.gov (United States)

    Huo, Winifred M.

    1995-01-01

    Variational methods have proven invaluable in theoretical physics and chemistry, both for bound state problems and for the study of collision phenomena. For collisional problems they can be grouped into two types: those based on the Schroedinger equation and those based on the Lippmann-Schwinger equation. The application of the Schwinger variational (SV) method to e-molecule collisions and photoionization has been reviewed previously. The present chapter discusses the implementation of the SV method as applied to e-molecule collisions.

  16. Applied iterative methods

    CERN Document Server

    Hageman, Louis A

    2004-01-01

    This graduate-level text examines the practical use of iterative methods in solving large, sparse systems of linear algebraic equations and in resolving multidimensional boundary-value problems. Assuming minimal mathematical background, it profiles the relative merits of several general iterative procedures. Topics include polynomial acceleration of basic iterative methods, Chebyshev and conjugate gradient acceleration procedures applicable to partitioning the linear system into a "red/black" block form, adaptive computational algorithms for the successive overrelaxation (SOR) method, and comp

  17. Well testing: interpretation methods

    Energy Technology Data Exchange (ETDEWEB)

    Bourdarot, G. [Elf Aquitaine, 92 - Courbevoie (France)

    1998-12-31

    This book presents the different methods to use for interpreting well tests: conventional methods, type curves, derivative, according to the type of reservoir limits (faults, channels, secant faults, constant pressure limits, closed reservoir) and the well configuration (partial penetration, inclined, fractured, horizontal or injection well). It indicates the method to be used in the case of more complex reservoirs (fissured reservoirs, two-layered reservoirs), interference tests or pulse tests and when fluid produced is gas or polyphasic. (authors) 60 refs.

  18. Well testing: interpretation methods

    Energy Technology Data Exchange (ETDEWEB)

    Bourdarot, G. (Elf Aquitaine, 92 - Courbevoie (France))

    1998-01-01

    This book presents the different methods to use for interpreting well tests: conventional methods, type curves, derivative, according to the type of reservoir limits (faults, channels, secant faults, constant pressure limits, closed reservoir) and the well configuration (partial penetration, inclined, fractured, horizontal or injection well). It indicates the method to be used in the case of more complex reservoirs (fissured reservoirs, two-layered reservoirs), interference tests or pulse tests and when fluid produced is gas or polyphasic. (authors) 60 refs.

  19. The Box Method

    DEFF Research Database (Denmark)

    Nielsen, Peter Vilhelm

    The velocity level in a room ventilated by jet ventilation is strongly influenced by the supply conditions. The momentum flow in the supply jets controls the air movement in the room and, therefore, it is very important that the inlet conditions and the numerical method can generate a satisfactor...... description of this momentum flow. The Box Method is a practical method for the description of an Air Terminal Device which will save grid points and ensure the right level of the momentum flow....

  20. Methods of inventory control.

    Science.gov (United States)

    Lindley, C; Mackowiak, J

    1985-01-01

    Various methods for controlling inventory are described, and the advantages and disadvantages of each are discussed. The open-to-buy (OTB) budget method limits purchases to a specific amount of funds available for purchasing pharmaceuticals during a specified period. The emphasis of the OTB method is financial control of the pharmacy inventory. Although it is useful in monitoring and adjusting the dollar value of the inventory, it should be combined with other methods for a total inventory control system. The primary emphasis of the short-list method is to provide accurate and timely inventory information to the person responsible for order placement. The short list identifies the items that are in short supply. It is the most common feedback and control mechanism in use, but it is best suited for settings where duplicate or reserve stock is maintained and monitored by more rigorous methods. The main objective of the minimum and maximum method is to determine when and how much to order of each item. It also provides limited dollar control. The major disadvantage of this method is the time it requires to establish the minimum and maximum levels and to update them regularly to reflect changes in demand. The stock record card method is used to record information on the movement of goods in and out of the storage area. Stock cards can also be used to monitor inventory levels and facilitate order initiation. It is probably the optimum method to be used alone. The most effective system of inventory control is one employing a combination of these methods tailored to meet the institution's needs and available resources.

  1. Methods for data classification

    Science.gov (United States)

    Garrity, George; Lilburn, Timothy G.

    2011-10-11

    The present invention provides methods for classifying data and uncovering and correcting annotation errors. In particular, the present invention provides a self-organizing, self-correcting algorithm for use in classifying data. Additionally, the present invention provides a method for classifying biological taxa.

  2. DISCOURSE ON METHODS.

    Science.gov (United States)

    BOUCHER, JOHN G.

    THE AUTHOR STATES THAT BEFORE PRESENT FOREIGN LANGUAGE TEACHING METHODS CAN BE DISCUSSED INTELLIGENTLY, THE RESEARCH IN PSYCHOLOGY AND LINGUISTICS WHICH HAS INFLUENCED THE DEVELOPMENT OF THESE METHODS MUST BE CONSIDERED. MANY FOREIGN LANGUAGE TEACHERS WERE BEGINNING TO FEEL COMFORTABLE WITH THE AUDIOLINGUAL APPROACH WHEN NOAM CHOMSKY, IN HIS 1966…

  3. Noise-Measuring Method

    DEFF Research Database (Denmark)

    Diamond, J. M.

    1965-01-01

    A noise-measuring method based on the use of a calibrated noise generator and an output meter with a special scale is described. The method eliminates the effect of noise contributions occurring in the circuits following the device under test....

  4. Method of forming nanodielectrics

    Science.gov (United States)

    Tuncer, Enis [Knoxville, TN; Polyzos, Georgios [Oak Ridge, TN

    2014-01-07

    A method of making a nanoparticle filled dielectric material. The method includes mixing nanoparticle precursors with a polymer material and reacting the nanoparticle mixed with the polymer material to form nanoparticles dispersed within the polymer material to form a dielectric composite.

  5. Soybean allergen detection methods

    DEFF Research Database (Denmark)

    Pedersen, Mona H; Holzhauser, Thomas; Bisson, Caroline

    2008-01-01

    Soybean containing products are widely consumed, thus reliable methods for detection of soy in foods are needed in order to make appropriate risk assessment studies to adequately protect soy allergic patients. Six methods were compared using eight food products with a declared content of soy...

  6. The Method of Archimedes.

    Science.gov (United States)

    Del Grande, John

    1993-01-01

    Describes the method that Archimedes utilized to calculate the volumes of spheres and other solids. The method found the volume of a sphere by comparing the mass of parallel slices of a sphere and a cone with that of a cylinder of known mass. (MDH)

  7. Research Methods in Education

    Science.gov (United States)

    Check, Joseph; Schutt, Russell K.

    2011-01-01

    "Research Methods in Education" introduces research methods as an integrated set of techniques for investigating questions about the educational world. This lively, innovative text helps students connect technique and substance, appreciate the value of both qualitative and quantitative methodologies, and make ethical research decisions.…

  8. METHOD FOR MAKING CHEESE

    DEFF Research Database (Denmark)

    2010-01-01

    The present invention relates to a method for making Cheddar type and Continental type cheese with an adjunct culture comprising a Lactobacillus helveticus strain.......The present invention relates to a method for making Cheddar type and Continental type cheese with an adjunct culture comprising a Lactobacillus helveticus strain....

  9. Improved nonlinear prediction method

    Science.gov (United States)

    Adenan, Nur Hamiza; Md Noorani, Mohd Salmi

    2014-06-01

    The analysis and prediction of time series data have been addressed by researchers. Many techniques have been developed to be applied in various areas, such as weather forecasting, financial markets and hydrological phenomena involving data that are contaminated by noise. Therefore, various techniques to improve the method have been introduced to analyze and predict time series data. In respect of the importance of analysis and the accuracy of the prediction result, a study was undertaken to test the effectiveness of the improved nonlinear prediction method for data that contain noise. The improved nonlinear prediction method involves the formation of composite serial data based on the successive differences of the time series. Then, the phase space reconstruction was performed on the composite data (one-dimensional) to reconstruct a number of space dimensions. Finally the local linear approximation method was employed to make a prediction based on the phase space. This improved method was tested with data series Logistics that contain 0%, 5%, 10%, 20% and 30% of noise. The results show that by using the improved method, the predictions were found to be in close agreement with the observed ones. The correlation coefficient was close to one when the improved method was applied on data with up to 10% noise. Thus, an improvement to analyze data with noise without involving any noise reduction method was introduced to predict the time series data.

  10. Data center cooling method

    Energy Technology Data Exchange (ETDEWEB)

    Chainer, Timothy J.; Dang, Hien P.; Parida, Pritish R.; Schultz, Mark D.; Sharma, Arun

    2015-08-11

    A method aspect for removing heat from a data center may use liquid coolant cooled without vapor compression refrigeration on a liquid cooled information technology equipment rack. The method may also include regulating liquid coolant flow to the data center through a range of liquid coolant flow values with a controller-apparatus based upon information technology equipment temperature threshold of the data center.

  11. Studying Aid: Some Methods

    NARCIS (Netherlands)

    D.R. Gasper (Des)

    2003-01-01

    textabstractINVESTIGATING IDEAS, IDEOLOGIES AND PRACTICES This paper presents some methods for trying to make sense of international aid and of its study.1 Some of the methods may be deemed ethnographic; the others are important partners to them, but rather different. In the course of discussing q

  12. Research Methods in Education

    Science.gov (United States)

    Check, Joseph; Schutt, Russell K.

    2011-01-01

    "Research Methods in Education" introduces research methods as an integrated set of techniques for investigating questions about the educational world. This lively, innovative text helps students connect technique and substance, appreciate the value of both qualitative and quantitative methodologies, and make ethical research decisions.…

  13. METHODS OF MAGNETOTELLURIC ANALYSIS

    Science.gov (United States)

    Magnetotelluric prospecting is a method of geophysical exploration that makes use of the fluctuations in the natural electric and magnetic fields...function of the conductivity structure of the earth’s substrata. This report describes some new methods for analyzing and interpreting magnetotelluric

  14. Methods in Modern Biophysics

    CERN Document Server

    Nölting, Bengt

    2006-01-01

    Incorporating recent dramatic advances, this textbook presents a fresh and timely introduction to modern biophysical methods. An array of new, faster and higher-power biophysical methods now enables scientists to examine the mysteries of life at a molecular level. This innovative text surveys and explains the ten key biophysical methods, including those related to biophysical nanotechnology, scanning probe microscopy, X-ray crystallography, ion mobility spectrometry, mass spectrometry, proteomics, and protein folding and structure. Incorporating much information previously unavailable in tutorial form, Nölting employs worked examples and 267 illustrations to fully detail the techniques and their underlying mechanisms. Methods in Modern Biophysics is written for advanced undergraduate and graduate students, postdocs, researchers, lecturers and professors in biophysics, biochemistry and related fields. Special features in the 2nd edition: • Illustrates the high-resolution methods for ultrashort-living protei...

  15. Adaptive method of lines

    CERN Document Server

    Saucez, Ph

    2001-01-01

    The general Method of Lines (MOL) procedure provides a flexible format for the solution of all the major classes of partial differential equations (PDEs) and is particularly well suited to evolutionary, nonlinear wave PDEs. Despite its utility, however, there are relatively few texts that explore it at a more advanced level and reflect the method''s current state of development.Written by distinguished researchers in the field, Adaptive Method of Lines reflects the diversity of techniques and applications related to the MOL. Most of its chapters focus on a particular application but also provide a discussion of underlying philosophy and technique. Particular attention is paid to the concept of both temporal and spatial adaptivity in solving time-dependent PDEs. Many important ideas and methods are introduced, including moving grids and grid refinement, static and dynamic gridding, the equidistribution principle and the concept of a monitor function, the minimization of a functional, and the moving finite elem...

  16. Fast Distributed Gradient Methods

    CERN Document Server

    Jakovetic, Dusan; Moura, Jose M F

    2011-01-01

    The paper proposes new fast distributed optimization gradient methods and proves convergence to the exact solution at rate O(\\log k/k), much faster than existing distributed optimization (sub)gradient methods with convergence O(1/\\sqrt{k}), while incurring practically no additional communication nor computation cost overhead per iteration. We achieve this for convex (with at least one strongly convex,) coercive, three times differentiable and with Lipschitz continuous first derivative (private) cost functions. Our work recovers for distributed optimization similar convergence rate gains obtained by centralized Nesterov gradient and fast iterative shrinkage-thresholding algorithm (FISTA) methods over ordinary centralized gradient methods. We also present a constant step size distributed fast gradient algorithm for composite non-differentiable costs. A simulation illustrates the effectiveness of our distributed methods.

  17. Cooperative method development

    DEFF Research Database (Denmark)

    Dittrich, Yvonne; Rönkkö, Kari; Eriksson, Jeanette;

    2008-01-01

    research is not easily combined with the improvement orientation of an engineering discipline. During the last 6 years, we have applied an approach we call `cooperative method development', which combines qualitative social science fieldwork, with problem-oriented method, technique and process improvement....... The action research based approach focusing on shop floor software development practices allows an understanding of how contextual contingencies influence the deployment and applicability of methods, processes and techniques. This article summarizes the experiences and discusses the further development......The development of methods tools and process improvements is best to be based on the understanding of the development practice to be supported. Qualitative research has been proposed as a method for understanding the social and cooperative aspects of software development. However, qualitative...

  18. Engaging with mobile methods

    DEFF Research Database (Denmark)

    Jensen, Martin Trandberg

    2014-01-01

    This chapter showcases how mobile methods are more than calibrated techniques awaiting application by tourism researchers, but productive in the enactment of the mobile (Law and Urry, 2004). Drawing upon recent findings deriving from a PhD course on mobility and mobile methods it reveals...... the conceptual ambiguousness of the term ‘mobile methods’. In order to explore this ambiguousness the chapter provides a number of examples deriving from tourism research, to explore how mobile methods are always entangled in ideologies, predispositions, conventions and practice-realities. Accordingly......, the engagements with methods are acknowledged to be always political and contextual, reminding us to avoid essentialist discussions regarding research methods. Finally, the chapter draws on recent fieldwork to extend developments in mobilities-oriented tourism research, by employing auto-ethnography to call...

  19. Methods for age estimation

    Directory of Open Access Journals (Sweden)

    D. Sümeyra Demirkıran

    2014-03-01

    Full Text Available Concept of age estimation plays an important role on both civil law and regulation of criminal behaviors. In forensic medicine, age estimation is practiced for individual requests as well for request of the court. In this study it is aimed to compile the methods of age estimation and to make recommendations for the solution of the problems encountered. In radiological method the epiphyseal lines of the bones and views of the teeth are used. In order to estimate the age by comparing bone radiographs; Greulich-Pyle Atlas (GPA, Tanner-Whitehouse Atlas (TWA and “Adli Tıpta Yaş Tayini (ATYT” books are used. Bone age is found to be 2 years older averagely than chronologic age, especially in puberty, according to the forensic age estimations described in the ATYT book. For the age estimation with teeth, Demirjian method is used. In time different methods are developed by modifying Demirjian method. However no accurate method was found. Histopathological studies are done on bone marrow cellularity and dermis cells. No correlation was found between histopathoogical findings and choronologic age. Important ethical and legal issues are brought with current age estimation methods especially in teenage period. Therefore it is required to prepare atlases of bone age compatible with our society by collecting the findings of the studies in Turkey. Another recommendation could be to pay attention to the courts of age raising trials of teenage women and give special emphasis on birth and population records

  20. STATISTICAL METHODS IN HISTORY

    Directory of Open Access Journals (Sweden)

    Orlov A. I.

    2016-01-01

    Full Text Available We have given a critical analysis of statistical models and methods for processing text information in historical records to establish the times when there were certain events, ie, to build science-based chronology. There are three main kinds of sources of knowledge of ancient history: ancient texts, the remains of material culture and traditions. The specific date of the extracted by archaeologists objects in most cases can not be found. The group of Academician A.T. Fomenko has developed and applied new statistical methods for analysis of historical texts (Chronicle, based on the intensive use of computer technology. Two major scientific results were: the majority of historical records that we know now, are duplicated (in particular, chronicles, describing the so-called "Ancient Rome" and "Middle Ages", talking about the same events; the known historical chronicles tell us about real events, separated from the present time for not more than 1000 years. It was found that chronicles describing the history of "ancient times" and "Middle Ages" and the chronicle of Chinese history and the history of various European countries do not talk about different, but about the same events. We have the attempt of a new dating of historical events and restoring the true history of human society based on new data. From the standpoint of statistical methods of historical records and images of their fragments – they are special cases of non-numeric objects of nature. Therefore, developed by the group of A.T. Fomenko computer-statistical methods are the part of non-numerical statistics. We have considered some methods of statistical analysis of chronicles applied by the group of A.T. Fomenko: correlation method of maximums; dynasties method; the method of attenuation frequency; questionnaire method codes. New chronology allows us to understand much of the battle of ideas in modern science and mass consciousness. It becomes clear the root cause of cautious

  1. Classification-based summation of cerebral digital subtraction angiography series for image post-processing algorithms

    Energy Technology Data Exchange (ETDEWEB)

    Schuldhaus, D; Spiegel, M; Polyanskaya, M; Hornegger, J [Pattern Recognition Lab, University Erlangen-Nuremberg (Germany); Redel, T [Siemens AG Healthcare Sector, Forchheim (Germany); Struffert, T; Doerfler, A, E-mail: martin.spiegel@informatik.uni-erlangen.de [Department of Neuroradiology, University Erlangen-Nuremberg (Germany)

    2011-03-21

    X-ray-based 2D digital subtraction angiography (DSA) plays a major role in the diagnosis, treatment planning and assessment of cerebrovascular disease, i.e. aneurysms, arteriovenous malformations and intracranial stenosis. DSA information is increasingly used for secondary image post-processing such as vessel segmentation, registration and comparison to hemodynamic calculation using computational fluid dynamics. Depending on the amount of injected contrast agent and the duration of injection, these DSA series may not exhibit one single DSA image showing the entire vessel tree. The interesting information for these algorithms, however, is usually depicted within a few images. If these images would be combined into one image the complexity of segmentation or registration methods using DSA series would drastically decrease. In this paper, we propose a novel method automatically splitting a DSA series into three parts, i.e. mask, arterial and parenchymal phase, to provide one final image showing all important vessels with less noise and moving artifacts. This final image covers all arterial phase images, either by image summation or by taking the minimum intensities. The phase classification is done by a two-step approach. The mask/arterial phase border is determined by a Perceptron-based method trained from a set of DSA series. The arterial/parenchymal phase border is specified by a threshold-based method. The evaluation of the proposed method is two-sided: (1) comparison between automatic and medical expert-based phase selection and (2) the quality of the final image is measured by gradient magnitudes inside the vessels and signal-to-noise (SNR) outside. Experimental results show a match between expert and automatic phase separation of 93%/50% and an average SNR increase of up to 182% compared to summing up the entire series.

  2. Classification-based summation of cerebral digital subtraction angiography series for image post-processing algorithms

    Science.gov (United States)

    Schuldhaus, D.; Spiegel, M.; Redel, T.; Polyanskaya, M.; Struffert, T.; Hornegger, J.; Doerfler, A.

    2011-03-01

    X-ray-based 2D digital subtraction angiography (DSA) plays a major role in the diagnosis, treatment planning and assessment of cerebrovascular disease, i.e. aneurysms, arteriovenous malformations and intracranial stenosis. DSA information is increasingly used for secondary image post-processing such as vessel segmentation, registration and comparison to hemodynamic calculation using computational fluid dynamics. Depending on the amount of injected contrast agent and the duration of injection, these DSA series may not exhibit one single DSA image showing the entire vessel tree. The interesting information for these algorithms, however, is usually depicted within a few images. If these images would be combined into one image the complexity of segmentation or registration methods using DSA series would drastically decrease. In this paper, we propose a novel method automatically splitting a DSA series into three parts, i.e. mask, arterial and parenchymal phase, to provide one final image showing all important vessels with less noise and moving artifacts. This final image covers all arterial phase images, either by image summation or by taking the minimum intensities. The phase classification is done by a two-step approach. The mask/arterial phase border is determined by a Perceptron-based method trained from a set of DSA series. The arterial/parenchymal phase border is specified by a threshold-based method. The evaluation of the proposed method is two-sided: (1) comparison between automatic and medical expert-based phase selection and (2) the quality of the final image is measured by gradient magnitudes inside the vessels and signal-to-noise (SNR) outside. Experimental results show a match between expert and automatic phase separation of 93%/50% and an average SNR increase of up to 182% compared to summing up the entire series.

  3. Classification-based summation of cerebral digital subtraction angiography series for image post-processing algorithms.

    Science.gov (United States)

    Schuldhaus, D; Spiegel, M; Redel, T; Polyanskaya, M; Struffert, T; Hornegger, J; Doerfler, A

    2011-03-21

    X-ray-based 2D digital subtraction angiography (DSA) plays a major role in the diagnosis, treatment planning and assessment of cerebrovascular disease, i.e. aneurysms, arteriovenous malformations and intracranial stenosis. DSA information is increasingly used for secondary image post-processing such as vessel segmentation, registration and comparison to hemodynamic calculation using computational fluid dynamics. Depending on the amount of injected contrast agent and the duration of injection, these DSA series may not exhibit one single DSA image showing the entire vessel tree. The interesting information for these algorithms, however, is usually depicted within a few images. If these images would be combined into one image the complexity of segmentation or registration methods using DSA series would drastically decrease. In this paper, we propose a novel method automatically splitting a DSA series into three parts, i.e. mask, arterial and parenchymal phase, to provide one final image showing all important vessels with less noise and moving artifacts. This final image covers all arterial phase images, either by image summation or by taking the minimum intensities. The phase classification is done by a two-step approach. The mask/arterial phase border is determined by a Perceptron-based method trained from a set of DSA series. The arterial/parenchymal phase border is specified by a threshold-based method. The evaluation of the proposed method is two-sided: (1) comparison between automatic and medical expert-based phase selection and (2) the quality of the final image is measured by gradient magnitudes inside the vessels and signal-to-noise (SNR) outside. Experimental results show a match between expert and automatic phase separation of 93%/50% and an average SNR increase of up to 182% compared to summing up the entire series.

  4. The Prescribed Velocity Method

    DEFF Research Database (Denmark)

    Nielsen, Peter Vilhelm

    The- velocity level in a room ventilated by jet ventilation is strongly influenced by the supply conditions. The momentum flow in the supply jets controls the air movement in the room and, therefore, it is very important that the inlet conditions and the numerical method can generate a satisfactory...... description of this momentum flow. The Prescribed Velocity Method is a practical method for the description of an Air Terminal Device which will save grid points close to the opening and ensure the right level of the momentum flow....

  5. Methods in mummy research

    DEFF Research Database (Denmark)

    Lynnerup, Niels

    2009-01-01

    Mummies are human remains with preservation of non-bony tissue. Many mummy studies focus on the development and application of non-destructive methods for examining mummies, including radiography, CT-scanning with advanced 3-dimensional visualisations, and endoscopic techniques, as well as minima......Mummies are human remains with preservation of non-bony tissue. Many mummy studies focus on the development and application of non-destructive methods for examining mummies, including radiography, CT-scanning with advanced 3-dimensional visualisations, and endoscopic techniques, as well...... as minimally-destructive chemical, physical and biological methods for, e.g., stable isotopes, trace metals and DNA....

  6. Modern diffraction methods

    CERN Document Server

    Mittemeijer, E J

    2013-01-01

    The role of diffraction methods for the solid-state sciences has been pivotal to determining the (micro)structure of a material. Particularly, the expanding activities in materials science have led to the development of new methods for analysis by diffraction. This book offers an authoritative overview of the new developments in the field of analysis of matter by (in particular X-ray, electron and neutron) diffraction. It is composed of chapters written by leading experts on 'modern diffraction methods'. The focus in the various chapters of this book is on the current forefront of research on

  7. Methods in Bioengineering

    CERN Document Server

    Jayaraman, Arul

    2009-01-01

    This volume provides a detailed look at the two main aspects of systems biology: the design of sophisticated experimental methods and the development of complex models to analyze the data. Focusing on methods that are being used to solve current problems in biomedical science and engineering, this comprehensive, richly illustrated resource shows you how to design of state-of-the art methods for analyzing biological systems, implement experimental approaches for investigating cellular behavior in health and disease, use algorithms and modeling techniques for quantitatively describing biomedical

  8. Montessori Method and ICTs

    Directory of Open Access Journals (Sweden)

    Athanasios Drigas

    2016-03-01

    Full Text Available This article bridges the gap between the Montessori Method and Information and Communication Technologies (ICTs in contemporary education. It reviews recent research works which recall the Montessori philosophy, principles and didactical tools applying to today’s computers and supporting technologies in children’s learning process. This article reviews how important the stimulation of human senses in the learning process is, as well as the development of Montessori materials using the body and the hand in particular, all according to the Montessori Method along with recent researches over ICTs. Montessori Method within information society age acquires new perspectives, new functionality and new efficacy.

  9. Numerical methods using Matlab

    CERN Document Server

    Lindfield, George

    2012-01-01

    Numerical Methods using MATLAB, 3e, is an extensive reference offering hundreds of useful and important numerical algorithms that can be implemented into MATLAB for a graphical interpretation to help researchers analyze a particular outcome. Many worked examples are given together with exercises and solutions to illustrate how numerical methods can be used to study problems that have applications in the biosciences, chaos, optimization, engineering and science across the board. Numerical Methods using MATLAB, 3e, is an extensive reference offering hundreds of use

  10. Methods of flash sintering

    Energy Technology Data Exchange (ETDEWEB)

    Raj, Rishi; Cologna, Marco; Francis, John S.

    2016-05-10

    This disclosure provides methods of flash sintering and compositions created by these methods. Methods for sintering multilayered bodies are provided in which a sintered body is produced in less than one minute. In one aspect, each layer is of a different composition, and may be constituted wholly from a ceramic or from a combination of ceramic and metallic particles. When the body includes a layer of an anode composition, a layer of an electrolyte composition and a layer of a cathode composition, the sintered body can be used to produce a solid oxide fuel cell.

  11. Structural Reliability Methods

    DEFF Research Database (Denmark)

    Ditlevsen, Ove Dalager; Madsen, H. O.

    of structural reliability, including the theoretical basis for these methods. Partial safety factor codes under current practice are briefly introduced and discussed. A probabilistic code format for obtaining a formal reliability evaluation system that catches the most essential features of the nature......The structural reliability methods quantitatively treat the uncertainty of predicting the behaviour and properties of a structure given the uncertain properties of its geometry, materials, and the actions it is supposed to withstand. This book addresses the probabilistic methods for evaluation...

  12. Generalized subspace correction methods

    Energy Technology Data Exchange (ETDEWEB)

    Kolm, P. [Royal Institute of Technology, Stockholm (Sweden); Arbenz, P.; Gander, W. [Eidgenoessiche Technische Hochschule, Zuerich (Switzerland)

    1996-12-31

    A fundamental problem in scientific computing is the solution of large sparse systems of linear equations. Often these systems arise from the discretization of differential equations by finite difference, finite volume or finite element methods. Iterative methods exploiting these sparse structures have proven to be very effective on conventional computers for a wide area of applications. Due to the rapid development and increasing demand for the large computing powers of parallel computers, it has become important to design iterative methods specialized for these new architectures.

  13. Ensemble Data Mining Methods

    Science.gov (United States)

    Oza, Nikunj C.

    2004-01-01

    Ensemble Data Mining Methods, also known as Committee Methods or Model Combiners, are machine learning methods that leverage the power of multiple models to achieve better prediction accuracy than any of the individual models could on their own. The basic goal when designing an ensemble is the same as when establishing a committee of people: each member of the committee should be as competent as possible, but the members should be complementary to one another. If the members are not complementary, Le., if they always agree, then the committee is unnecessary---any one member is sufficient. If the members are complementary, then when one or a few members make an error, the probability is high that the remaining members can correct this error. Research in ensemble methods has largely revolved around designing ensembles consisting of competent yet complementary models.

  14. Adaptive Algebraic Multigrid Methods

    Energy Technology Data Exchange (ETDEWEB)

    Brezina, M; Falgout, R; MacLachlan, S; Manteuffel, T; McCormick, S; Ruge, J

    2004-04-09

    Our ability to simulate physical processes numerically is constrained by our ability to solve the resulting linear systems, prompting substantial research into the development of multiscale iterative methods capable of solving these linear systems with an optimal amount of effort. Overcoming the limitations of geometric multigrid methods to simple geometries and differential equations, algebraic multigrid methods construct the multigrid hierarchy based only on the given matrix. While this allows for efficient black-box solution of the linear systems associated with discretizations of many elliptic differential equations, it also results in a lack of robustness due to assumptions made on the near-null spaces of these matrices. This paper introduces an extension to algebraic multigrid methods that removes the need to make such assumptions by utilizing an adaptive process. The principles which guide the adaptivity are highlighted, as well as their application to algebraic multigrid solution of certain symmetric positive-definite linear systems.

  15. Methods for cellobiosan utilization

    Energy Technology Data Exchange (ETDEWEB)

    Linger, Jeffrey; Beckham, Gregg T.

    2017-07-11

    Disclosed herein are enzymes useful for the degradation of cellobiosan in materials such a pyrolysis oils. Methods of degrading cellobiosan using enzymes or organisms expressing the same are also disclosed.

  16. Compressive Spectral Renormalization Method

    CERN Document Server

    Bayindir, Cihan

    2016-01-01

    In this paper a novel numerical scheme for finding the sparse self-localized states of a nonlinear system of equations with missing spectral data is introduced. As in the Petviashivili's and the spectral renormalization method, the governing equation is transformed into Fourier domain, but the iterations are performed for far fewer number of spectral components (M) than classical versions of the these methods with higher number of spectral components (N). After the converge criteria is achieved for M components, N component signal is reconstructed from M components by using the l1 minimization technique of the compressive sampling. This method can be named as compressive spectral renormalization (CSRM) method. The main advantage of the CSRM is that, it is capable of finding the sparse self-localized states of the evolution equation(s) with many spectral data missing.

  17. Iii. Sleep assessment methods.

    Science.gov (United States)

    Sadeh, Avi

    2015-03-01

    Sleep is a complex phenomenon that could be understood and assessed at many levels. Sleep could be described at the behavioral level (relative lack of movements and awareness and responsiveness) and at the brain level (based on EEG activity). Sleep could be characterized by its duration, by its distribution during the 24-hr day period, and by its quality (e.g., consolidated versus fragmented). Different methods have been developed to assess various aspects of sleep. This chapter covers the most established and common methods used to assess sleep in infants and children. These methods include polysomnography, videosomnography, actigraphy, direct observations, sleep diaries, and questionnaires. The advantages and disadvantages of each method are highlighted.

  18. Stochastic optimization methods

    CERN Document Server

    Marti, Kurt

    2005-01-01

    Optimization problems arising in practice involve random parameters. For the computation of robust optimal solutions, i.e., optimal solutions being insensitive with respect to random parameter variations, deterministic substitute problems are needed. Based on the distribution of the random data, and using decision theoretical concepts, optimization problems under stochastic uncertainty are converted into deterministic substitute problems. Due to the occurring probabilities and expectations, approximative solution techniques must be applied. Deterministic and stochastic approximation methods and their analytical properties are provided: Taylor expansion, regression and response surface methods, probability inequalities, First Order Reliability Methods, convex approximation/deterministic descent directions/efficient points, stochastic approximation methods, differentiation of probability and mean value functions. Convergence results of the resulting iterative solution procedures are given.

  19. Methods for euclidean geometry

    CERN Document Server

    Byer, Owen; Smeltzer, Deirdre L

    2010-01-01

    Euclidean plane geometry is one of the oldest and most beautiful topics in mathematics. Instead of carefully building geometries from axiom sets, this book uses a wealth of methods to solve problems in Euclidean geometry. Many of these methods arose where existing techniques proved inadequate. In several cases, the new ideas used in solving specific problems later developed into independent areas of mathematics. This book is primarily a geometry textbook, but studying geometry in this way will also develop students' appreciation of the subject and of mathematics as a whole. For instance, despite the fact that the analytic method has been part of mathematics for four centuries, it is rarely a tool a student considers using when faced with a geometry problem. Methods for Euclidean Geometry explores the application of a broad range of mathematical topics to the solution of Euclidean problems.

  20. Methods in Modern Biophysics

    CERN Document Server

    Nölting, Bengt

    2010-01-01

    Incorporating recent dramatic advances, this textbook presents a fresh and timely introduction to modern biophysical methods. An array of new, faster and higher-power biophysical methods now enables scientists to examine the mysteries of life at a molecular level. This innovative text surveys and explains the ten key biophysical methods, including those related to biophysical nanotechnology, scanning probe microscopy, X-ray crystallography, ion mobility spectrometry, mass spectrometry, proteomics, and protein folding and structure. Incorporating much information previously unavailable in tutorial form, Nölting employs worked examples and about 270 illustrations to fully detail the techniques and their underlying mechanisms. Methods in Modern Biophysics is written for advanced undergraduate and graduate students, postdocs, researchers, lecturers, and professors in biophysics, biochemistry and related fields. Special features in the 3rd edition: Introduces rapid partial protein ladder sequencing - an important...

  1. Concrete compositions and methods

    Science.gov (United States)

    Chen, Irvin; Lee, Patricia Tung; Patterson, Joshua

    2015-06-23

    Provided herein are compositions, methods, and systems for cementitious compositions containing calcium carbonate compositions and aggregate. The compositions find use in a variety of applications, including use in a variety of building materials and building applications.

  2. Monte Carlo methods

    OpenAIRE

    Bardenet, R.

    2012-01-01

    ISBN:978-2-7598-1032-1; International audience; Bayesian inference often requires integrating some function with respect to a posterior distribution. Monte Carlo methods are sampling algorithms that allow to compute these integrals numerically when they are not analytically tractable. We review here the basic principles and the most common Monte Carlo algorithms, among which rejection sampling, importance sampling and Monte Carlo Markov chain (MCMC) methods. We give intuition on the theoretic...

  3. Business forecasting methods

    OpenAIRE

    Skribans, V.

    2002-01-01

    The paper comprises three parts: description of the forecasting conception, classification of forecasting methods, and the general forecasting model. The first part deals with the definition of business forecasting, the second classifies and deals in more detail with the most frequently practiced forecasting methods and comes up with recommendations how to apply them in specific situations. The third part present the analysis of newly established forecasting model.

  4. Bidirectional beam propagation method

    Science.gov (United States)

    Kaczmarski, P.; Lagasse, P. E.

    1988-05-01

    A bidirectional extension of the beam propagation method (BPM) to optical waveguides with a longitudinal discontinuity is presented. The algorithm is verified by computing a reflection of the TE(0) mode from a semiconductor laser facet. The bidirectional BPM is applicable to other configurations such as totally reflecting waveguide mirrors, an abruption transition in a waveguide, or a waveguide with many discontinuities generating multiple reflections. The method can also be adapted to TM polarization.

  5. Method of treating depression

    Energy Technology Data Exchange (ETDEWEB)

    Henn, Fritz

    2013-04-09

    Methods for treatment of depression-related mood disorders in mammals, particularly humans are disclosed. The methods of the invention include administration of compounds capable of enhancing glutamate transporter activity in the brain of mammals suffering from depression. ATP-sensitive K.sup.+ channel openers and .beta.-lactam antibiotics are used to enhance glutamate transport and to treat depression-related mood disorders and depressive symptoms.

  6. Method of treating depression

    Science.gov (United States)

    Henn, Fritz [East Patchogue, NY

    2012-01-24

    Methods for treatment of depression-related mood disorders in mammals, particularly humans are disclosed. The methods of the invention include administration of compounds capable of enhancing glutamate transporter activity in the brain of mammals suffering from depression. ATP-sensitive K.sup.+ channel openers and .beta.-lactam antibiotics are used to enhance glutamate transport and to treat depression-related mood disorders and depressive symptoms.

  7. On Danish Legal Method

    DEFF Research Database (Denmark)

    Schaumburg-Müller, Sten

    2014-01-01

    On the basis on 1) the Danish legal writer A.S.Ørsted (1778-1860) and 2) an enquete among present day Danish legal scholars, the contribution deals with special traits in Danish legal method......On the basis on 1) the Danish legal writer A.S.Ørsted (1778-1860) and 2) an enquete among present day Danish legal scholars, the contribution deals with special traits in Danish legal method...

  8. Methods for polymer synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Allen, Scott D.; Simoneau, Christopher A.; Keefe, William D.; Conuel, Jeff R.

    2016-12-06

    The present invention provides methods for reducing induction periods in epoxide-CO.sub.2 copolymerizations. In certain embodiments, the methods include the step of contacting an epoxide with CO.sub.2 in the presence of two catalysts: an epoxide hydrolysis catalyst and an epoxide CO.sub.2 copolymerization catalyst. In another aspect, the invention provides catalyst compositions comprising a mixture of an epoxide hydrolysis catalyst and an epoxide CO.sub.2 copolymerization catalyst.

  9. Modern Methods in Marketing

    OpenAIRE

    Jandová, Pavlína

    2007-01-01

    Traditional marketing methods are losing their effectiveness and credibility. It has been worse and worse to communicate with customers, and marketers are therefore looking for new techniques and way how to appeal buyers. They turn to the use of modern marketing methods, which typical features are possibility of accurate targeting and low costs, and, also, the fact that they are still not considered being a classic promotion. In the theoretical part of the diploma thesis the alternative marke...

  10. Painful Bile Extraction Methods

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    It was only in the past 20 years that countries in Asia began to search for an alternative to protect moon bears from being killed for their bile and other body parts. In the early 1980s, a new method of extracting bile from living bears was developed in North Korea. In 1983, Chinese scientists imported this technique from North Korea. According to the Animals Asia Foundation, the most original method of bile extraction is to embed a latex catheter, a narrow rubber

  11. [Unproven methods in oncology].

    Science.gov (United States)

    Jallut, O; Guex, P; Barrelet, L

    1984-09-08

    As in some other chronic diseases (rheumatism, multiple sclerosis, etc.), unproven methods of diagnosis and treatment have long been current in cancer. Since 1960 the American Cancer Society has published an abundant literature on these "unproven methods", which serves as a basis for a historical review: some substances (Krebiozen, Laetrile) have enjoyed tremendous if shortlived success. The present trend is back to nature and "mild medicine". The proponents of this so-called natural medicine are often disciples of a pseudoscientific religion using irrational arguments. Direct attacks on these erroneous theories and their public refutation fail to convince the adepts, who trust in these methods and are not amenable to a scientific approach. Study of their psychological motivations reveals that in fact they seek something more reassuring than plain medical explanation which is aware of its limits. They feel reassured by theories which often bear some resemblance to the old popular medicine. To protect patients against these dangerous methods and all the disillusionment they entail, the Swiss Society of Oncology and the Swiss Cancer League have decided to gather information and draw up a descriptive list of the commonest unproven methods in Switzerland (our File No. 2, "Total anti-cancer cure", is given as an example). The files are published in French, German and English and are available to physicians, nursing teams, and also patients who wish to have more objective information on these methods.

  12. Multicriteria identification sets method

    Science.gov (United States)

    Kamenev, G. K.

    2016-11-01

    A multicriteria identification and prediction method for mathematical models of simulation type in the case of several identification criteria (error functions) is proposed. The necessity of the multicriteria formulation arises, for example, when one needs to take into account errors of completely different origins (not reducible to a single characteristic) or when there is no information on the class of noise in the data to be analyzed. An identification sets method is described based on the approximation and visualization of the multidimensional graph of the identification error function and sets of suboptimal parameters. This method allows for additional advantages of the multicriteria approach, namely, the construction and visual analysis of the frontier and the effective identification set (frontier and the Pareto set for identification criteria), various representations of the sets of Pareto effective and subeffective parameter combinations, and the corresponding predictive trajectory tubes. The approximation is based on the deep holes method, which yields metric ɛ-coverings with nearly optimal properties, and on multiphase approximation methods for the Edgeworth-Pareto hull. The visualization relies on the approach of interactive decision maps. With the use of the multicriteria method, multiple-choice solutions of identification and prediction problems can be produced and justified by analyzing the stability of the optimal solution not only with respect to the parameters (robustness with respect to data) but also with respect to the chosen set of identification criteria (robustness with respect to the given collection of functionals).

  13. [Barrier methods of contraception].

    Science.gov (United States)

    Goldsmith, A; Edelman, D A

    1982-01-01

    Vaginal methods of contraception were the earliest types used and some references to them date back to antiquity. Most of the vaginal contraceptive agents identified by the ancient Greeks, Indians, Japanese, and Chinese have been found in modern laboratory tests to have spermicidal properties, but it is doubtful that the methods were fully reliable or were used by many people. During the 19th century the condom, vaginal spermicides, and diaphragm became available. The development of nonoxynol-9 and other nonirritating but effective spermicidal agents improved vaginal contraceptives greatly by the 1950s, but starting in the 1960s newer methods began to replace the vaginal methods. Interest in barrier methods has been reawakened somewhat by concern about the health effects of hormonal methods. At present all barrier methods leave something to be desired. Failure rates of 3-30% for barrier methods in general have been estimated, but the higher rates are believed due to incorrect or inconsistent use. Theoretical failure rates of condoms and diaphragms have been estimated at 3/100 women-years, but in actual use failure rates may reach 15 for condoms and 13 for diaphragms used with spermicides. Use-effectiveness rates are greatly influenced by motivation. For a variety of reasons, the acceptability of barrier methods is low, especially in developing countries. New developments in spermicidal agents include sperm inhibitors, which impede the fertilizing capacity of sperm rather than attempting a spermicidal effect; a number of such agents have been studied and have proven more effective in animal tests than conventional spermicides. Neosampoon, a new spermicidal foam, has attracted an increasing number of users, especially in developing countries. A new condom, made of thin polymers and containing a standard dose of nonoxynol-9, has been designed to dissolve in the vaginal fluid. Further studies are needed of its acceptability, efficacy, and side effects before it becomes

  14. The ICARE Method

    Science.gov (United States)

    Henke, Luke

    2010-01-01

    The ICARE method is a flexible, widely applicable method for systems engineers to solve problems and resolve issues in a complete and comprehensive manner. The method can be tailored by diverse users for direct application to their function (e.g. system integrators, design engineers, technical discipline leads, analysts, etc.). The clever acronym, ICARE, instills the attitude of accountability, safety, technical rigor and engagement in the problem resolution: Identify, Communicate, Assess, Report, Execute (ICARE). This method was developed through observation of Space Shuttle Propulsion Systems Engineering and Integration (PSE&I) office personnel approach in an attempt to succinctly describe the actions of an effective systems engineer. Additionally it evolved from an effort to make a broadly-defined checklist for a PSE&I worker to perform their responsibilities in an iterative and recursive manner. The National Aeronautics and Space Administration (NASA) Systems Engineering Handbook states, engineering of NASA systems requires a systematic and disciplined set of processes that are applied recursively and iteratively for the design, development, operation, maintenance, and closeout of systems throughout the life cycle of the programs and projects. ICARE is a method that can be applied within the boundaries and requirements of NASA s systems engineering set of processes to provide an elevated sense of duty and responsibility to crew and vehicle safety. The importance of a disciplined set of processes and a safety-conscious mindset increases with the complexity of the system. Moreover, the larger the system and the larger the workforce, the more important it is to encourage the usage of the ICARE method as widely as possible. According to the NASA Systems Engineering Handbook, elements of a system can include people, hardware, software, facilities, policies and documents; all things required to produce system-level results, qualities, properties, characteristics

  15. VALUATION METHODS- LITERATURE REVIEW

    Directory of Open Access Journals (Sweden)

    Dorisz Talas

    2015-07-01

    Full Text Available This paper is a theoretical overview of the often used valuation methods with the help of which the value of a firm or its equity is calculated. Many experts (including Aswath Damodaran, Guochang Zhang and CA Hozefa Natalwala classify the methods. The basic models are based on discounted cash flows. The main method uses the free cash flow for valuation, but there are some newer methods that reveal and correct the weaknesses of the traditional models. The valuation of flexibility of management can be conducted mainly with real options. This paper briefly describes the essence of the Dividend Discount Model, the Free Cash Flow Model, the benefit from using real options and the Residual Income Model. There are a few words about the Adjusted Present Value approach as well. Different models uses different premises, and an overall truth is that if the required premises are real and correct, the value will be appropriately accurate. Another important condition is that experts, analysts should choose between the models on the basis of the purpose of valuation. Thus there are no good or bad methods, only methods that fit different goals and aims. The main task is to define exactly the purpose, then to find the most appropriate valuation technique. All the methods originates from the premise that the value of an asset is the present value of its future cash flows. According to the different points of view of different techniques the resulted values can be also differed from each other. Valuation models and techniques should be adapted to the rapidly changing world, but the basic statements remain the same. On the other hand there is a need for more accurate models in order to help investors get as many information as they could. Today information is one of the most important resources and financial models should keep up with this trend.

  16. Molecular methods for biofilms

    KAUST Repository

    Ferrera, Isabel

    2014-08-30

    This chapter deals with both classical and modern molecular methods that can be useful for the identification of microorganisms, elucidation and comparison of microbial communities, and investigation of their diversity and functions. The most important and critical steps necessary for all molecular methods is DNA isolation from microbial communities and environmental samples; these are discussed in the first part. The second part provides an overview over DNA polymerase chain reaction (PCR) amplification and DNA sequencing methods. Protocols and analysis software as well as potential pitfalls associated with application of these methods are discussed. Community fingerprinting analyses that can be used to compare multiple microbial communities are discussed in the third part. This part focuses on Denaturing Gradient Gel Electrophoresis (DGGE), Terminal Restriction Fragment Length Polymorphism (T-RFLP) and Automated rRNA Intergenic Spacer Analysis (ARISA) methods. In addition, classical and next-generation metagenomics methods are presented. These are limited to bacterial artificial chromosome and Fosmid libraries and Sanger and next-generation 454 sequencing, as these methods are currently the most frequently used in research. Isolation of nucleic acids: This chapter discusses, the most important and critical steps necessary for all molecular methods is DNA isolation from microbial communities and environmental samples. Nucleic acid isolation methods generally include three steps: cell lysis, removal of unwanted substances, and a final step of DNA purification and recovery. The first critical step is the cell lysis, which can be achieved by enzymatic or mechanical procedures. Removal of proteins, polysaccharides and other unwanted substances is likewise important to avoid their interference in subsequent analyses. Phenol-chloroform-isoamyl alcohol is commonly used to recover DNA, since it separates nucleic acids into an aqueous phase and precipitates proteins and

  17. New oligosaccharyltransferase assay method.

    Science.gov (United States)

    Kohda, Daisuke; Yamada, Masaki; Igura, Mayumi; Kamishikiryo, Jun; Maenaka, Katsumi

    2007-11-01

    We developed a new in vitro assay for oligosaccharyltransferase (OST), which catalyzes the transfer of preassembled oligosaccharides on lipid carriers onto asparagine residues in polypeptide chains. The asparagine residues reside in the sequon, Asn-X-Thr/Ser, where X can be any amino acid residue except Pro. We demonstrate the potency of our assay using the OST from yeast. In our method, polyacrylamide gel electrophoresis is used to separate the glycopeptide products from the peptide substrates. The substrate peptide is fluorescently labeled and the formation of glycopeptides is analyzed by fluorescence gel imaging. Two in vitro OST assay methods are now widely used, but both the methods depend on previous knowledge of the oligosaccharide moiety: One method uses lectin binding as the separation mechanism and the other method uses biosynthetically or chemoenzymatically synthesized lipid-linked oligosaccharides as donors. N-linked protein glycosylation is found in all three domains of life, but little is known about the N-glycosylation in Archaea. Thus, our new assay, which does not require a priori knowledge of the oligosaccharides, will be useful in such cases. Indeed, we have detected the OST activity in the membrane fraction from a hyperthermophilic archaeon, Pyrococcus furiosus.

  18. Methods for Neutron Spectrometry

    Science.gov (United States)

    Brockhouse, Bertram N.

    1961-01-09

    The appropriate theories and the general philosophy of methods of measurement and treatment of data neutron spectrometry are discussed. Methods of analysis of results for liquids using the Van Hove formulation, and for crystals using the Born-von Karman theory, are reviewed. The most useful of the available methods of measurement are considered to be the crystal spectrometer methods and the pulsed monoenergetic beam/time-of-flight method. Pulsed-beam spectrometers have the advantage of higher counting rates than crystal spectrometers, especially in view of the fact that simultaneous measurements in several counters at different angles of scattering are possible in pulsed-beam spectrometers. The crystal spectrometer permits several valuable new types of specialized experiments to be performed, especially energy distribution measurements at constant momentum transfer. The Chalk River triple-axis crystal-spectrometer is discussed, with reference to its use in making the specialized experiments. The Chalk River rotating crystal (pulsed-beam) spectrometer is described, and a comparison of this type instrument with other pulsed-beam spectrometers is made. A partial outline of the theory of operation of rotating-crystal spectrometers is presented. The use of quartz-crystal filters for fast neutron elimination and for order elimination is discussed. (auth)

  19. The lod score method.

    Science.gov (United States)

    Rice, J P; Saccone, N L; Corbett, J

    2001-01-01

    The lod score method originated in a seminal article by Newton Morton in 1955. The method is broadly concerned with issues of power and the posterior probability of linkage, ensuring that a reported linkage has a high probability of being a true linkage. In addition, the method is sequential, so that pedigrees or lod curves may be combined from published reports to pool data for analysis. This approach has been remarkably successful for 50 years in identifying disease genes for Mendelian disorders. After discussing these issues, we consider the situation for complex disorders, where the maximum lod score (MLS) statistic shares some of the advantages of the traditional lod score approach but is limited by unknown power and the lack of sharing of the primary data needed to optimally combine analytic results. We may still learn from the lod score method as we explore new methods in molecular biology and genetic analysis to utilize the complete human DNA sequence and the cataloging of all human genes.

  20. Fashion, Mediations & Method Assemblages

    DEFF Research Database (Denmark)

    Sommerlund, Julie; Jespersen, Astrid Pernille

    , respectively. The paper thus takes on aesthetics and the social in a manner closely related to a core argument of STS - namely that the scientific fact, and the social processes of constructing, distributing, and using that fact, are co-constructed (Callon, 1986; Latour, 1993). The paper thus contributes......, it is an important ambition of this paper to go into a methodological discussion of how "that which effectively happens" can be approached. To this end, the paper will combine Hennion's term of the "mediator" with John Laws methodological term of "method assemblages". Method assemblages is a suggested as a way...... of handling multiple, fluid realities with multiple, fluid methods. Empirically, the paper works with mediation in fashion - that is efforts the active shaping of relations between producer and consumer through communication, marketing and PR. Fashion mediation is by no means simple, but organise complex...

  1. Cytoskeleton - Methods and Protocols

    Directory of Open Access Journals (Sweden)

    CarloAlberto Redi

    2010-03-01

    Full Text Available Cytoskeleton - Methods and ProtocolsSecond edition, 2010; Ray H. Gavin (Ed; Springer Protocols methods in molecular biology, vol. 586 Humana press, Totowa, New Jersey (USA; Pages: 390; €95.44; ISBN: 978-1-60761-375-6Ray H. Gavin, from the Brooklyn College of The City University of New York, Brooklyn, NY, USA, wrote a few line as preface of this book. This is quite understandable: there is not a great need of words when there are facts that sustain and favour the dissemination of a cultural product. This is the case of the second edition of Cytoskeleton - Methods and Protocols, which appears just ten years after the first edition...

  2. Geostatistical Methods in R

    Directory of Open Access Journals (Sweden)

    Adéla Volfová

    2012-10-01

    Full Text Available Geostatistics is a scientific field which provides methods for processing spatial data.  In our project, geostatistics is used as a tool for describing spatial continuity and making predictions of some natural phenomena. An open source statistical project called R is used for all calculations. Listeners will be provided with a brief introduction to R and its geostatistical packages and basic principles of kriging and cokriging methods. Heavy mathematical background is omitted due to its complexity. In the second part of the presentation, several examples are shown of how to make a prediction in the whole area of interest where observations were made in just a few points. Results of these methods are compared.

  3. Robust iterative methods

    Energy Technology Data Exchange (ETDEWEB)

    Saadd, Y.

    1994-12-31

    In spite of the tremendous progress achieved in recent years in the general area of iterative solution techniques, there are still a few obstacles to the acceptance of iterative methods in a number of applications. These applications give rise to very indefinite or highly ill-conditioned non Hermitian matrices. Trying to solve these systems with the simple-minded standard preconditioned Krylov subspace methods can be a frustrating experience. With the mathematical and physical models becoming more sophisticated, the typical linear systems which we encounter today are far more difficult to solve than those of just a few years ago. This trend is likely to accentuate. This workshop will discuss (1) these applications and the types of problems that they give rise to; and (2) recent progress in solving these problems with iterative methods. The workshop will end with a hopefully stimulating panel discussion with the speakers.

  4. Energy methods in dynamics

    CERN Document Server

    Le, Khanh Chau

    2012-01-01

    The above examples should make clear the necessity of understanding the mechanism of vibrations and waves in order to control them in an optimal way. However vibrations and waves are governed by differential equations which require, as a rule, rather complicated mathematical methods for their analysis. The aim of this textbook is to help students acquire both a good grasp of the first principles from which the governing equations can be derived, and the adequate mathematical methods for their solving. Its distinctive features, as seen from the title, lie in the systematic and intensive use of Hamilton's variational principle and its generalizations for deriving the governing equations of conservative and dissipative mechanical systems, and also in providing the direct variational-asymptotic analysis, whenever available, of the energy and dissipation for the solution of these equations. It will be demonstrated that many well-known methods in dynamics like those of Lindstedt-Poincare, Bogoliubov-Mitropolsky, Ko...

  5. Energy methods in dynamics

    CERN Document Server

    Le, Khanh Chau

    2014-01-01

    Energy Methods in Dynamics is a textbook based on the lectures given by the first author at Ruhr University Bochum, Germany. Its aim is to help students acquire both a good grasp of the first principles from which the governing equations can be derived, and the adequate mathematical methods for their solving. Its distinctive features, as seen from the title, lie in the systematic and intensive use of Hamilton's variational principle and its generalizations for deriving the governing equations of conservative and dissipative mechanical systems, and also in providing the direct variational-asymptotic analysis, whenever available, of the energy and dissipation for the solution of these equations. It demonstrates that many well-known methods in dynamics like those of Lindstedt-Poincare, Bogoliubov-Mitropolsky, Kolmogorov-Arnold-Moser (KAM), Wentzel–Kramers–Brillouin (WKB),  and Whitham are derivable from this variational-asymptotic analysis.   This second edition includes the solutions to all exercises as w...

  6. Sampling system and method

    Energy Technology Data Exchange (ETDEWEB)

    Decker, David L.; Lyles, Brad F.; Purcell, Richard G.; Hershey, Ronald Lee

    2017-03-07

    In one embodiment, the present disclosure provides an apparatus and method for supporting a tubing bundle during installation or removal. The apparatus includes a clamp for securing the tubing bundle to an external wireline. In various examples, the clamp is external to the tubing bundle or integral with the tubing bundle. According to one method, a tubing bundle and wireline are deployed together and the tubing bundle periodically secured to the wireline using a clamp. In another embodiment, the present disclosure provides an apparatus and method for coupling conduit segments together. A first pump obtains a sample and transmits it through a first conduit to a reservoir accessible by a second pump. The second pump further conducts the sample from the reservoir through a second conduit. In a specific example, one or more clamps are used to connect the first and/or second conduits to an external wireline.

  7. Grid generation methods

    CERN Document Server

    Liseikin, Vladimir D

    2017-01-01

    This new edition provides a description of current developments relating to grid methods, grid codes, and their applications to actual problems. Grid generation methods are indispensable for the numerical solution of differential equations. Adaptive grid-mapping techniques, in particular, are the main focus and represent a promising tool to deal with systems with singularities. This 3rd edition includes three new chapters on numerical implementations (10), control of grid properties (11), and applications to mechanical, fluid, and plasma related problems (13). Also the other chapters have been updated including new topics, such as curvatures of discrete surfaces (3). Concise descriptions of hybrid mesh generation, drag and sweeping methods, parallel algorithms for mesh generation have been included too. This new edition addresses a broad range of readers: students, researchers, and practitioners in applied mathematics, mechanics, engineering, physics and other areas of applications.

  8. Method of treating wells

    Energy Technology Data Exchange (ETDEWEB)

    Knox, J.A.; Lasater, R.M.

    1966-11-22

    Chemical compositions and methods are provided for treating underground formations to render their surfaces water-repellent or preferentially oil-wettable. Previous methods have provided only temporary water-repellency because they do not actually act chemically with the reservoir rock. This improvement is obtained by using a treating agent which does not form a precipitate upon hydrolysis with water, such as a liquid organo-halogen- silane or its ester. A water-soluble anhydrous solvent which is nonreactive with the silane is used as a carrier. This method may be used for treating non-oil-bearing aquifers for increasing the flow rate of water, such as in water supply wells, or in water input rate, such as in water disposal wells. (10 claims)

  9. Methods for RNA Analysis

    DEFF Research Database (Denmark)

    Olivarius, Signe

    of the transcriptome, 5’ end capture of RNA is combined with next-generation sequencing for high-throughput quantitative assessment of transcription start sites by two different methods. The methods presented here allow for functional investigation of coding as well as noncoding RNA and contribute to future......While increasing evidence appoints diverse types of RNA as key players in the regulatory networks underlying cellular differentiation and metabolism, the potential functions of thousands of conserved RNA structures encoded in mammalian genomes remain to be determined. Since the functions of most...... RNAs rely on interactions with proteins, the establishment of protein-binding profiles is essential for the characterization of RNAs. Aiming to facilitate RNA analysis, this thesis introduces proteomics- as well as transcriptomics-based methods for the functional characterization of RNA. First, RNA...

  10. Model Correction Factor Method

    DEFF Research Database (Denmark)

    Christensen, Claus; Randrup-Thomsen, Søren; Morsing Johannesen, Johannes

    1997-01-01

    The model correction factor method is proposed as an alternative to traditional polynomial based response surface techniques in structural reliability considering a computationally time consuming limit state procedure as a 'black box'. The class of polynomial functions is replaced by a limit...... statebased on an idealized mechanical model to be adapted to the original limit state by the model correction factor. Reliable approximations are obtained by iterative use of gradient information on the original limit state function analogously to previous response surface approaches. However, the strength...... of the model correction factor method, is that in simpler form not using gradient information on the original limit state function or only using this information once, a drastic reduction of the number of limit state evaluation is obtained together with good approximations on the reliability. Methods...

  11. Splines and variational methods

    CERN Document Server

    Prenter, P M

    2008-01-01

    One of the clearest available introductions to variational methods, this text requires only a minimal background in calculus and linear algebra. Its self-contained treatment explains the application of theoretic notions to the kinds of physical problems that engineers regularly encounter. The text's first half concerns approximation theoretic notions, exploring the theory and computation of one- and two-dimensional polynomial and other spline functions. Later chapters examine variational methods in the solution of operator equations, focusing on boundary value problems in one and two dimension

  12. Nonparametric statistical methods

    CERN Document Server

    Hollander, Myles; Chicken, Eric

    2013-01-01

    Praise for the Second Edition"This book should be an essential part of the personal library of every practicing statistician."-Technometrics  Thoroughly revised and updated, the new edition of Nonparametric Statistical Methods includes additional modern topics and procedures, more practical data sets, and new problems from real-life situations. The book continues to emphasize the importance of nonparametric methods as a significant branch of modern statistics and equips readers with the conceptual and technical skills necessary to select and apply the appropriate procedures for any given sit

  13. METHOD OF ROLLING URANIUM

    Science.gov (United States)

    Smith, C.S.

    1959-08-01

    A method is described for rolling uranium metal at relatively low temperatures and under non-oxidizing conditions. The method involves the steps of heating the uranium to 200 deg C in an oil bath, withdrawing the uranium and permitting the oil to drain so that only a thin protective coating remains and rolling the oil coated uranium at a temperature of 200 deg C to give about a 15% reduction in thickness at each pass. The operation may be repeated to accomplish about a 90% reduction without edge cracking, checking or any appreciable increase in brittleness.

  14. Electrorheological fluids and methods

    Energy Technology Data Exchange (ETDEWEB)

    Green, Peter F.; McIntyre, Ernest C.

    2015-06-02

    Electrorheological fluids and methods include changes in liquid-like materials that can flow like milk and subsequently form solid-like structures under applied electric fields; e.g., about 1 kV/mm. Such fluids can be used in various ways as smart suspensions, including uses in automotive, defense, and civil engineering applications. Electrorheological fluids and methods include one or more polar molecule substituted polyhedral silsesquioxanes (e.g., sulfonated polyhedral silsesquioxanes) and one or more oils (e.g., silicone oil), where the fluid can be subjected to an electric field.

  15. Tautomerism methods and theories

    CERN Document Server

    Antonov, Liudmil

    2013-01-01

    Covering the gap between basic textbooks and over-specialized scientific publications, this is the first reference available to describe this interdisciplinary topic for PhD students and scientists starting in the field. The result is an introductory description providing suitable practical examples of the basic methods used to study tautomeric processes, as well as the theories describing the tautomerism and proton transfer phenomena. It also includes different spectroscopic methods for examining tautomerism, such as UV-VIs, time-resolved fluorescence spectroscopy, and NMR spectrosc

  16. Unorthodox theoretical methods

    Energy Technology Data Exchange (ETDEWEB)

    Nedd, Sean [Iowa State Univ., Ames, IA (United States)

    2012-01-01

    The use of the ReaxFF force field to correlate with NMR mobilities of amine catalytic substituents on a mesoporous silica nanosphere surface is considered. The interfacing of the ReaxFF force field within the Surface Integrated Molecular Orbital/Molecular Mechanics (SIMOMM) method, in order to replicate earlier SIMOMM published data and to compare with the ReaxFF data, is discussed. The development of a new correlation consistent Composite Approach (ccCA) is presented, which incorporates the completely renormalized coupled cluster method with singles, doubles and non-iterative triples corrections towards the determination of heats of formations and reaction pathways which contain biradical species.

  17. Exploring Monte Carlo methods

    CERN Document Server

    Dunn, William L

    2012-01-01

    Exploring Monte Carlo Methods is a basic text that describes the numerical methods that have come to be known as "Monte Carlo." The book treats the subject generically through the first eight chapters and, thus, should be of use to anyone who wants to learn to use Monte Carlo. The next two chapters focus on applications in nuclear engineering, which are illustrative of uses in other fields. Five appendices are included, which provide useful information on probability distributions, general-purpose Monte Carlo codes for radiation transport, and other matters. The famous "Buffon's needle proble

  18. Method through motion

    DEFF Research Database (Denmark)

    Steijn, Arthur

    2016-01-01

    Contemporary scenography often consists of video-projected motion graphics. The field is lacking in academic methods and rigour: descriptions and models relevant for the creation as well as in the analysis of existing works. In order to understand the phenomenon of motion graphics in a scenographic...... construction as a support to working systematically practice-led research project. The design model is being developed through design laboratories and workshops with students and professionals who provide feedback that lead to incremental improvements. Working with this model construction-as-method reveals...

  19. Methods of visualizing graphs

    Science.gov (United States)

    Wong, Pak C.; Mackey, Patrick S.; Perrine, Kenneth A.; Foote, Harlan P.; Thomas, James J.

    2008-12-23

    Methods for visualizing a graph by automatically drawing elements of the graph as labels are disclosed. In one embodiment, the method comprises receiving node information and edge information from an input device and/or communication interface, constructing a graph layout based at least in part on that information, wherein the edges are automatically drawn as labels, and displaying the graph on a display device according to the graph layout. In some embodiments, the nodes are automatically drawn as labels instead of, or in addition to, the label-edges.

  20. Methods of Multivariate Analysis

    CERN Document Server

    Rencher, Alvin C

    2012-01-01

    Praise for the Second Edition "This book is a systematic, well-written, well-organized text on multivariate analysis packed with intuition and insight . . . There is much practical wisdom in this book that is hard to find elsewhere."-IIE Transactions Filled with new and timely content, Methods of Multivariate Analysis, Third Edition provides examples and exercises based on more than sixty real data sets from a wide variety of scientific fields. It takes a "methods" approach to the subject, placing an emphasis on how students and practitioners can employ multivariate analysis in real-life sit

  1. Methods for pretreating biomass

    Science.gov (United States)

    Balan, Venkatesh; Dale, Bruce E; Chundawat, Shishir; Sousa, Leonardo

    2017-05-09

    A method for pretreating biomass is provided, which includes, in a reactor, allowing gaseous ammonia to condense on the biomass and react with water present in the biomass to produce pretreated biomass, wherein reactivity of polysaccharides in the biomass is increased during subsequent biological conversion as compared to the reactivity of polysaccharides in biomass which has not been pretreated. A method for pretreating biomass with a liquid ammonia and recovering the liquid ammonia is also provided. Related systems which include a biochemical or biofuel production facility are also disclosed.

  2. Apoptosis - Methods and Protocols

    Directory of Open Access Journals (Sweden)

    CarloAlberto Redi

    2010-03-01

    Full Text Available Apoptosis - Methods and ProtocolsSecond edition, 2009; Peter Erhardt and Ambrus Toth (Eds; Springer Protocols - Methods in molecular biology, vol. 559; Humana press, Totowa, New Jersey (USA; Pages: 400; €88.35; ISBN: 978-1-60327-016-8The editors rightly begin the preface telling us that: “The ability to detect and quantify apoptosis, to understand its biochemistry and to identify its regulatory genes and proteins is crucial to biomedical research”. Nowadays this is a grounding concept of biology and medicine. What is particularly remarkable...

  3. Practical methods of optimization

    CERN Document Server

    Fletcher, R

    2013-01-01

    Fully describes optimization methods that are currently most valuable in solving real-life problems. Since optimization has applications in almost every branch of science and technology, the text emphasizes their practical aspects in conjunction with the heuristics useful in making them perform more reliably and efficiently. To this end, it presents comparative numerical studies to give readers a feel for possibile applications and to illustrate the problems in assessing evidence. Also provides theoretical background which provides insights into how methods are derived. This edition offers rev

  4. Essential numerical computer methods

    CERN Document Server

    Johnson, Michael L

    2010-01-01

    The use of computers and computational methods has become ubiquitous in biological and biomedical research. During the last 2 decades most basic algorithms have not changed, but what has is the huge increase in computer speed and ease of use, along with the corresponding orders of magnitude decrease in cost. A general perception exists that the only applications of computers and computer methods in biological and biomedical research are either basic statistical analysis or the searching of DNA sequence data bases. While these are important applications they only scratch the surface

  5. Analogue computing methods

    CERN Document Server

    Welbourne, D

    1965-01-01

    Analogue Computing Methods presents the field of analogue computation and simulation in a compact and convenient form, providing an outline of models and analogues that have been produced to solve physical problems for the engineer and how to use and program the electronic analogue computer. This book consists of six chapters. The first chapter provides an introduction to analogue computation and discusses certain mathematical techniques. The electronic equipment of an analogue computer is covered in Chapter 2, while its use to solve simple problems, including the method of scaling is elaborat

  6. Making Methods Choices.

    Science.gov (United States)

    Patton, Michael Quinn

    1980-01-01

    Methodological paradigms in evaluation research are discussed. This article is a response to the attacks on paradigmatic perspectives made by Reichardt and Cook in the opening chapter of their edited book, "Qualitative and Quantitative Methods in Evaluation Research." (Author/GK)

  7. communication method and apparatus

    DEFF Research Database (Denmark)

    2005-01-01

    The present invention relates to a non-lingual communication method and apparatus, wherein a physical or physiological signal consciously created by a first subject (1) is detected and converted into a transmitted output signal presented to a second subject (7) in order to communicate information...

  8. METHOD OF CENTRIFUGE OPERATION

    Science.gov (United States)

    Cohen, K.

    1960-05-10

    A method of isotope separation is described in which two streams are flowed axially of, and countercurrently through, a cylindrical centrifuge bowl. Under the influence of a centrifugal field, the light fraction is concentrated in a stream flowing through the central portion of the bowl, whereas the heavy fraction is concentrated in a stream at the periphery thereof.

  9. Ferrari's Method and Technology

    Science.gov (United States)

    Althoen, Steve

    2005-01-01

    Some tips that combine knowledge of mathematics history and technology for adapting Ferrar's method to factor quintics with a TI-83 graphing calculator are presented. A demonstration on the use of the root finder and regression capabilities of the graphing calculator are presented, so that the tips can be easily adapted for any graphing calculator…

  10. The Mnemonic Keyword Method.

    Science.gov (United States)

    Pressley, Michael; And Others

    1982-01-01

    Available experimental evidence is reviewed concerning the keyword method, a two-stage procedure for remembering materials having an associative component. The review examines subjects' memory for definitions, given vocabulary words; subjects' learning of other aspects of vocabulary, given definitions; group-administered keyword studies; and…

  11. Modern Reduction Methods

    CERN Document Server

    Andersson, Pher G

    2008-01-01

    With its comprehensive overview of modern reduction methods, this book features high quality contributions allowing readers to find reliable solutions quickly and easily. The monograph treats the reduction of carbonyles, alkenes, imines and alkynes, as well as reductive aminations and cross and heck couplings, before finishing off with sections on kinetic resolutions and hydrogenolysis. An indispensable lab companion for every chemist.

  12. Analysis of numerical methods

    CERN Document Server

    Isaacson, Eugene

    1994-01-01

    This excellent text for advanced undergraduates and graduate students covers norms, numerical solution of linear systems and matrix factoring, iterative solutions of nonlinear equations, eigenvalues and eigenvectors, polynomial approximation, and other topics. It offers a careful analysis and stresses techniques for developing new methods, plus many examples and problems. 1966 edition.

  13. The Method of "Currere."

    Science.gov (United States)

    Pinar, William Frederick

    In this presentation the author paints a conceptual portrait of his evolving relationships to his formal studies and thereby describes a method by which educators can reconceptualize the meaning of curriculum. By taking oneself and one's existential experience as a data source and using the psychoanalytical technique of free association, one can…

  14. Universal Image Steganalytic Method

    Directory of Open Access Journals (Sweden)

    V. Banoci

    2014-12-01

    Full Text Available In the paper we introduce a new universal steganalytic method in JPEG file format that is detecting well-known and also newly developed steganographic methods. The steganalytic model is trained by MHF-DZ steganographic algorithm previously designed by the same authors. The calibration technique with the Feature Based Steganalysis (FBS was employed in order to identify statistical changes caused by embedding a secret data into original image. The steganalyzer concept utilizes Support Vector Machine (SVM classification for training a model that is later used by the same steganalyzer in order to identify between a clean (cover and steganographic image. The aim of the paper was to analyze the variety in accuracy of detection results (ACR while detecting testing steganographic algorithms as F5, Outguess, Model Based Steganography without deblocking, JP Hide and Seek which represent the generally used steganographic tools. The comparison of four feature vectors with different lengths FBS (22, FBS (66 FBS(274 and FBS(285 shows promising results of proposed universal steganalytic method comparing to binary methods.

  15. Methods Evolved by Observation

    Science.gov (United States)

    Montessori, Maria

    2016-01-01

    Montessori's idea of the child's nature and the teacher's perceptiveness begins with amazing simplicity, and when she speaks of "methods evolved," she is unveiling a methodological system for observation. She begins with the early childhood explosion into writing, which is a familiar child phenomenon that Montessori has written about…

  16. Method card design dimensions

    DEFF Research Database (Denmark)

    Wölfel, Christiane; Merritt, T.

    2013-01-01

    . The card-based tools are explained in terms of five design dimensions including the intended purpose and scope of use, duration of use, methodology, customization, and formal/material qualities. Our analysis suggests three design patterns or archetypes for existing card-based design method tools...

  17. Statistical methods in astronomy

    OpenAIRE

    Long, James P.; de Souza, Rafael S.

    2017-01-01

    We present a review of data types and statistical methods often encountered in astronomy. The aim is to provide an introduction to statistical applications in astronomy for statisticians and computer scientists. We highlight the complex, often hierarchical, nature of many astronomy inference problems and advocate for cross-disciplinary collaborations to address these challenges.

  18. Methods of materiality

    DEFF Research Database (Denmark)

    Aagaard, Jesper; Matthiesen, Noomi

    2016-01-01

    , and the method of participant observation is suggested as a viable approach to achieve this end. An empirical example of how authority is produced in a parent-teacher conference, not only through language but also through material objects and embodied being, is then presented. The article concludes by suggesting...

  19. Research Methods in Sociolinguistics

    Science.gov (United States)

    Hernández-Campoy, Juan Manuel

    2014-01-01

    The development of Sociolinguistics has been qualitatively and quantitatively outstanding within Linguistic Science since its beginning in the 1950s, with a steady growth in both theoretical and methodological developments as well as in its interdisciplinary directions within the spectrum of language and society. Field methods in sociolinguistic…

  20. Ergonomics research methods

    Science.gov (United States)

    Uspenskiy, S. I.; Yermakova, S. V.; Chaynova, L. D.; Mitkin, A. A.; Gushcheva, T. M.; Strelkov, Y. K.; Tsvetkova, N. F.

    1973-01-01

    Various factors used in ergonomic research are given. They are: (1) anthrometric measurement, (2) polyeffector method of assessing the functional state of man, (3) galvanic skin reaction, (4) pneumography, (5) electromyography, (6) electrooculography, and (7) tachestoscopy. A brief summary is given of each factor and includes instrumentation and results.

  1. A method for sintering

    DEFF Research Database (Denmark)

    2012-01-01

    The present invention provides a method for sintering, comprising in the following order the steps of: providing a body in the green state or in the pre-sintered state on a support; providing a load on at least one spacer on the support such that the load is located above said body in the green...

  2. Biomass treatment method

    Science.gov (United States)

    Friend, Julie; Elander, Richard T.; Tucker, III; Melvin P.; Lyons, Robert C.

    2010-10-26

    A method for treating biomass was developed that uses an apparatus which moves a biomass and dilute aqueous ammonia mixture through reaction chambers without compaction. The apparatus moves the biomass using a non-compressing piston. The resulting treated biomass is saccharified to produce fermentable sugars.

  3. Truth and Methods.

    Science.gov (United States)

    Dasenbrock, Reed Way

    1995-01-01

    Examines literary theory's displacing of "method" in the New Historicist criticism. Argues that Stephen Greenblatt and Lee Paterson imply that no objective historical truth is possible and as a result do not give methodology its due weight in their criticism. Questions the theory of "truth" advanced in this vein of literary…

  4. Software specification methods

    CERN Document Server

    Habrias, Henri

    2010-01-01

    This title provides a clear overview of the main methods, and has a practical focus that allows the reader to apply their knowledge to real-life situations. The following are just some of the techniques covered: UML, Z, TLA+, SAZ, B, OMT, VHDL, Estelle, SDL and LOTOS.

  5. Progress in variational methods

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ The International Conference on Variational Methods (ICVAM) was held from May 20th to 26th in 2007 at the Chern Institute of Mathematics, Nankai University, Tianjin, China. Twenty eight invited speakers from ten countries and areas worldwide gave their lectures at the conference.

  6. Heart imaging method

    Science.gov (United States)

    Collins, H. Dale; Gribble, R. Parks; Busse, Lawrence J.

    1991-01-01

    A method for providing an image of the human heart's electrical system derives time-of-flight data from an array of EKG electrodes and this data is transformed into phase information. The phase information, treated as a hologram, is reconstructed to provide an image in one or two dimensions of the electrical system of the functioning heart.

  7. Quality of regularization methods

    NARCIS (Netherlands)

    Bouwman, J.

    1998-01-01

    The solution of ill-posed problems is non-trivial in the sense that frequently applied methods like least-squares fail. The ill-posedness of the problem is refiected by very small changes in the input data which may result in very large changes in the output data. Hence, some sort of stabilization

  8. Methods of materiality

    DEFF Research Database (Denmark)

    Aagaard, Jesper; Matthiesen, Noomi

    2016-01-01

    , and the method of participant observation is suggested as a viable approach to achieve this end. An empirical example of how authority is produced in a parent-teacher conference, not only through language but also through material objects and embodied being, is then presented. The article concludes by suggesting...

  9. Proven Weight Loss Methods

    Science.gov (United States)

    Fact Sheet Proven Weight Loss Methods What can weight loss do for you? Losing weight can improve your health in a number of ways. ... limiting calories) usually isn’t enough to cause weight loss. But exercise plays an important part in helping ...

  10. Research Methods in Sociolinguistics

    Science.gov (United States)

    Hernández-Campoy, Juan Manuel

    2014-01-01

    The development of Sociolinguistics has been qualitatively and quantitatively outstanding within Linguistic Science since its beginning in the 1950s, with a steady growth in both theoretical and methodological developments as well as in its interdisciplinary directions within the spectrum of language and society. Field methods in sociolinguistic…

  11. Sampling system and method

    Science.gov (United States)

    Decker, David L.; Lyles, Brad F.; Purcell, Richard G.; Hershey, Ronald Lee

    2013-04-16

    The present disclosure provides an apparatus and method for coupling conduit segments together. A first pump obtains a sample and transmits it through a first conduit to a reservoir accessible by a second pump. The second pump further conducts the sample from the reservoir through a second conduit.

  12. Photothermal methods in medicine

    Science.gov (United States)

    Murphy, John C.

    2000-10-01

    Photothermal imaging and spectroscopy are being applied to a variety of medical problems for diagnosis and therapy. This paper reviews some aspects of this field including the opportunities presented by non-optical sources and by use of detection methods targeted to the application.

  13. Quality of regularization methods

    NARCIS (Netherlands)

    Bouwman, J.

    1998-01-01

    The solution of ill-posed problems is non-trivial in the sense that frequently applied methods like least-squares fail. The ill-posedness of the problem is refiected by very small changes in the input data which may result in very large changes in the output data. Hence, some sort of stabilization o

  14. Project execution methods

    National Research Council Canada - National Science Library

    John C Pfeiffer

    2004-01-01

      In the design/build (D/B) method of implementing plant construction projects, the owner contracts with the engineer/contractor or contractor/engineer company or team-depending upon who takes the lead in the project to develop...

  15. The Effective Equation Method

    Science.gov (United States)

    Kuksin, Sergei; Maiocchi, Alberto

    In this chapter we present a general method of constructing the effective equation which describes the behavior of small-amplitude solutions for a nonlinear PDE in finite volume, provided that the linear part of the equation is a hamiltonian system with a pure imaginary discrete spectrum. The effective equation is obtained by retaining only the resonant terms of the nonlinearity (which may be hamiltonian, or may be not); the assertion that it describes the limiting behavior of small-amplitude solutions is a rigorous mathematical theorem. In particular, the method applies to the three- and four-wave systems. We demonstrate that different possible types of energy transport are covered by this method, depending on whether the set of resonances splits into finite clusters (this happens, e.g. in case of the Charney-Hasegawa-Mima equation), or is connected (this happens, e.g. in the case of the NLS equation if the space-dimension is at least two). For equations of the first type the energy transition to high frequencies does not hold, while for equations of the second type it may take place. Our method applies to various weakly nonlinear wave systems, appearing in plasma, meteorology and oceanography.

  16. Teaching Materials and Methods.

    Science.gov (United States)

    Physiologist, 1987

    1987-01-01

    Contains abstracts of presented papers which deal with teaching materials and methods in physiology. Includes papers on preconceptual notions in physiology, somatosensory activity recorded in the dorsal root ganglion of the bull frog, and the use of the Apple Macintosh microcomputer in teaching human anatomy and physiology. (TW)

  17. Convergence of Arnoldi method

    Energy Technology Data Exchange (ETDEWEB)

    Nevanlinna, O. [Helsinki Univ. of Technology, Espoo (Finland)

    1994-12-31

    This note summarizes some results on (a monitored version of) the Arnoldi method in Hilbert spaces. The interest in working in infinite dimensional spaces comes partly from the fact that only then can one have meaningful asymptotical statements (which hopefully give some light to the convergence of Arnoldi in large dimensional problems with iteration indices far less than the dimension).

  18. Photovoltaic device and method

    Science.gov (United States)

    Cleereman, Robert; Lesniak, Michael J.; Keenihan, James R.; Langmaid, Joe A.; Gaston, Ryan; Eurich, Gerald K.; Boven, Michelle L.

    2015-11-24

    The present invention is premised upon an improved photovoltaic device ("PVD") and method of use, more particularly to an improved photovoltaic device with an integral locator and electrical terminal mechanism for transferring current to or from the improved photovoltaic device and the use as a system.

  19. Water-budget methods

    Science.gov (United States)

    Healy, Richard W.; Scanlon, Bridget R.

    2010-01-01

    A water budget is an accounting of water movement into and out of, and storage change within, some control volume. Universal and adaptable are adjectives that reflect key features of water-budget methods for estimating recharge. The universal concept of mass conservation of water implies that water-budget methods are applicable over any space and time scales (Healy et al., 2007). The water budget of a soil column in a laboratory can be studied at scales of millimeters and seconds. A water-budget equation is also an integral component of atmospheric general circulation models used to predict global climates over periods of decades or more. Water-budget equations can be easily customized by adding or removing terms to accurately portray the peculiarities of any hydrologic system. The equations are generally not bound by assumptions on mechanisms by which water moves into, through, and out of the control volume of interest. So water-budget methods can be used to estimate both diffuse and focused recharge, and recharge estimates are unaffected by phenomena such as preferential flow paths within the unsaturated zone. Water-budget methods represent the largest class of techniques for estimating recharge. Most hydrologic models are derived from a water-budget equation and can therefore be classified as water-budget models. It is not feasible to address all water-budget methods in a single chapter. This chapter is limited to discussion of the “residual” water-budget approach, whereby all variables in a water-budget equation, except for recharge, are independently measured or estimated and recharge is set equal to the residual. This chapter is closely linked with Chapter 3, on modeling methods, because the equations presented here form the basis of many models and because models are often used to estimate individual components in water-budget studies. Water budgets for streams and other surface-water bodies are addressed in Chapter 4. The use of soil-water budgets and

  20. Nonhazardous Urine Pretreatment Method

    Science.gov (United States)

    Akse, James R.; Holtsnider, John T.

    2012-01-01

    A method combines solid phase acidification with two non-toxic biocides to prevent ammonia volatilization and microbial proliferation. The safe, non-oxidizing biocide combination consists of a quaternary amine and a food preservative. This combination has exhibited excellent stabilization of both acidified and unacidified urine. During pretreatment tests, composite urine collected from donors was challenged with a microorganism known to proliferate in urine, and then was processed using the nonhazardous urine pre-treatment method. The challenge microorganisms included Escherichia coli, a common gram-negative bacteria; Enterococcus faecalis, a ureolytic gram-positive bacteria; Candida albicans, a yeast commonly found in urine; and Aspergillus niger, a problematic mold that resists urine pre-treatment. Urine processed in this manner remained microbially stable for over 57 days. Such effective urine stabilization was achieved using non-toxic, non-oxidizing biocides at higher pH (3.6 to 5.8) than previous methods in use or projected for use aboard the International Space Station (ISS). ISS urine pretreatment methods employ strong oxidants including ozone and hexavalent chromium (Cr(VI)), a carcinogenic material, under very acidic conditions (pH = 1.8 to 2.4). The method described here offers a much more benign chemical environment than previous pretreatment methods, and will lower equivalent system mass (ESM) by reducing containment volume and mass, system complexity, and crew time needed to handle pre-treatment chemicals. The biocides, being non-oxidizing, minimize the potential for chemical reactions with urine constituents to produce volatile, airborne contaminants such as cyanogen chloride. Additionally, the biocides are active under significantly less acidic conditions than those used in the current system, thereby reducing the degree of required acidification. A simple flow-through solid phase acidification (SPA) bed is employed to overcome the natural buffering

  1. Developments in Surrogating Methods

    Directory of Open Access Journals (Sweden)

    Hans van Dormolen

    2005-11-01

    Full Text Available In this paper, I would like to talk about the developments in surrogating methods for preservation. My main focus will be on the technical aspects of preservation surrogates. This means that I will tell you something about my job as Quality Manager Microfilming for the Netherlands’ national preservation program, Metamorfoze, which is coordinated by the National Library. I am responsible for the quality of the preservation microfilms, which are produced for Metamorfoze. Firstly, I will elaborate on developments in preservation methods in relation to the following subjects: · Preservation microfilms · Scanning of preservation microfilms · Preservation scanning · Computer Output Microfilm. In the closing paragraphs of this paper, I would like to tell you something about the methylene blue test. This is an important test for long-term storage of preservation microfilms. Also, I will give you a brief report on the Cellulose Acetate Microfilm Conference that was held in the British Library in London, May 2005.

  2. Motor degradation prediction methods

    Energy Technology Data Exchange (ETDEWEB)

    Arnold, J.R.; Kelly, J.F.; Delzingaro, M.J.

    1996-12-01

    Motor Operated Valve (MOV) squirrel cage AC motor rotors are susceptible to degradation under certain conditions. Premature failure can result due to high humidity/temperature environments, high running load conditions, extended periods at locked rotor conditions (i.e. > 15 seconds) or exceeding the motor`s duty cycle by frequent starts or multiple valve stroking. Exposure to high heat and moisture due to packing leaks, pressure seal ring leakage or other causes can significantly accelerate the degradation. ComEd and Liberty Technologies have worked together to provide and validate a non-intrusive method using motor power diagnostics to evaluate MOV rotor condition and predict failure. These techniques have provided a quick, low radiation dose method to evaluate inaccessible motors, identify degradation and allow scheduled replacement of motors prior to catastrophic failures.

  3. Mitosis Methods & Protocols

    Directory of Open Access Journals (Sweden)

    CarloAlberto Redi

    2010-06-01

    Full Text Available Mitosis Methods & Protocols Andrew D. McAinsh (Edt Humana press, Totowa, New Jersey (USA Series: Springer Protocols Methods in Molecular Biology, Volume 545, 2009 ISBN: 978-1-60327-992-5   It is quite clear from the contents of this book that the remarkably fascinating phenomenon of mitosis (that captured, and still is capturing, the attention of entire generations of scientists is still open to research. This is mainly due to our lack of knowledge of so many multifaced events of this extraordinarly complex process. The reader giving a glace through the Contents and Contributors sections is speechless: All of the first-class models (i.e., budding yeast, Caenorabditis, Drosophila, Xenopus and Human are presented..... 

  4. Method card design dimensions

    DEFF Research Database (Denmark)

    Wölfel, Christiane; Merritt, T.

    2013-01-01

    . The card-based tools are explained in terms of five design dimensions including the intended purpose and scope of use, duration of use, methodology, customization, and formal/material qualities. Our analysis suggests three design patterns or archetypes for existing card-based design method tools...... and highlights unexplored areas in the design space. The paper concludes with recommendations for the future development of card-based methods for the field of interaction design.......There are many examples of cards used to assist or provide structure to the design process, yet there has not been a thorough articulation of the strengths and weaknesses of the various examples. We review eighteen card-based design tools in order to understand how they might benefit designers...

  5. Jet vortex methods

    CERN Document Server

    Holm, Darryl D

    2015-01-01

    Vortex blob methods are typically characterized by a regularization length scale, below which the the dynamics are trivial for isolated blobs. In this article we will find that the dynamics need not be trivial if one is willing to consider distributional derivatives of Dirac delta functionals as valid vorticity distributions. More specifically, a new singular vortex theory is presented for regularised Euler fluid equations of ideal incompressible flow in the plane. We determine the conditions under which such regularised Euler fluid equations may admit vorticity singularities which are stronger than delta functions, e.g., derivatives of delta functions. We also characterise the Hamiltonian dynamics of the higher-order singular vortices. Applications to the design of numerical meth- ods similar to vortex blob methods are also discussed. Such findings shed light onto the rich dynamics which occur below the regularization length scale and enlighten our perspective on the multiscale aspects of regularized fluid m...

  6. The Montessori Method

    Directory of Open Access Journals (Sweden)

    Cathleen Haskins

    2010-06-01

    Full Text Available Dr. Maria Montessori provided the world with a powerful philosophy and practice for the advancement of humanity: change how we educate children and we change the world. She understood two things very clearly: One, that we can build a better world, a more just and peaceful place, when we educate for the realization of the individual and collective human potential; and two, that the only way to create an educational system that will that will serve this end is to scrap the current system entirely and replace it with a completely new system. She gave us a system through which to accomplish that goal: The Montessori Method. The following is a personal and professional account of the Montessori Method of educating children.

  7. in the DSMC Method

    Directory of Open Access Journals (Sweden)

    Fong-Zhi Chen

    2001-01-01

    Full Text Available In this study, the Plücker coordinates representation is used to formulate the ruled surface and the molecular path for pumping speed performance evaluation of a molecular vacuum pump. The ruled surface represented by the Pliicker coordinates is used to develop a criterion for when gas molecules hit the pump surface wall. The criterion is applied to analyze the flow rate of a new developed vacuum pump in transition regimes by using the DSMC (Direct Simulation Monte Carlo method. When a molecule flies in a neutral electrical field its path is a straight line. If the molecular path and the generators of a ruled surface are both represented by the Pliicker coordinates, the position of the molecular hit on the wall can be verified by the reciprocal condition of the lines. The Plücker coordinates representation is quite convenient in the DSMC method for this three-dimensional molecular flow simulation.

  8. Anthropological methods in ethnopharmacology.

    Science.gov (United States)

    Etkin, N L

    1993-03-01

    This paper reviews anthropological methods in ethnopharmacology to advance a critical and biobehavioral perspective for the construction of primary data in the light of indigenous paradigms of health and therapeutics. The unique contributions of anthropology are the conceptual and practical tools that allow one to develop the ethnography of plant use in sufficient depth to correlate with laboratory and clinical investigations of plant constituents and activities. This serves an ethnopharmacology that links bioscientific research to traditional empirical knowledge. Specific methods discussed include: key respondents, participant observation, focus groups, structured and unstructured interviews, survey instruments and questionnaires, lexical and semantic studies, and discourse and content analysis. The accommodation of rapid ethnographic techniques for ethnopharmacologic research is described, and several problem orientations based on assessments of efficacy are offered.

  9. INNOVATIVE SALES METHODS

    Directory of Open Access Journals (Sweden)

    Roxana L. IONESCU

    2014-06-01

    Full Text Available Companies operating in a global economy that is constantly changing and developming, especially during the financial crisis and political instability. It is necessary to adapt and develop sales methods in such environment. For large companies who base their activity on sales it has become a necessity to learn different types of sales approaches because their knowledge enables them to grow the number of customers and therefore the sales and the turnover. This paper aims to exame the most effective sales methods used on the highly sensitive economic and social environment – the insurance market. In the field of insurances, the sales process is even more important because sellers need to sell an intangible product that may materialize in the future, but there is no certainty.

  10. Dynamic encryption method

    DEFF Research Database (Denmark)

    2013-01-01

    Disclosed is a method of transmitting a data set using encryption, wherein the method comprises the steps of: selecting a first encryption technique, wherein said first encryption technique comprises a first encryption algorithm for encrypting plain data into cipher data, and a first decryption...... algorithm for on provision of a specific key, decrypting cipher data and reproduce plain data; encrypting the first data package comprising plain data, using a first encryption program implementing the first encryption algorithm of said first encryption technique, creating a first encrypted data package...... comprising cipher data; obtaining a first decryption program; and transmitting said first decryption program and said first encrypted data package to a receiver, wherein the first decryption, upon provision of the specific key and the first encrypted data package, will decrypt the cipher data in the first...

  11. by Lifting Line Method

    Directory of Open Access Journals (Sweden)

    Horia Dumitrescu

    1998-01-01

    Full Text Available The vortex model of propellers is modified and applied to the high-speed horizontal axis turbines. The turbine blades are replaced by lifting lines and trailing vortices which shed along the blade span. The model is not a free wake model, but it is still a nonlinear one which should be solved iteratively. In addition to the regular case where the trailing vortices are constrained to distribute along a helical surface, another version, where each trailing vortex sheding from the blade grows as a free helical vortex line, is also included. Performance parameters are calculated by application of the Biot-Savart law along with the Kutta-Joukowski theorem. Predictions are, shown to compare favorably with existing numerical data from more involved free wake methods, but require less computational effort. Thereby, the present method may be a very useful tool for calculating the aerodynamic loads on horizontal-axis wind turbine blades.

  12. THE ACTION RESEARCH METHOD

    Directory of Open Access Journals (Sweden)

    Petre GEORGIEVSKI

    1999-05-01

    Full Text Available The effort in this work to elaborate an action research method as a central research problem considering the recent contemporary sociological and educa­tional literature. The author begins with the statement that the method is a complex notion, composed of three main components: approach to the research problem, data gathering procedures and data analysis procedures. This point of view is further applied and elaborated in the author's text, emphasizing the action research characteristics: interruption with the positive tradition in social research and the divided of the objective and subjective, application of the qualitative data. The sub­stantial difference between the action research in regard with the other kinds of research, is not only in getting to new knowledge's, but also in problem solving or a change in the situation in a concrete social context.

  13. Nanoscale waveguiding methods.

    Science.gov (United States)

    Wang, Chia-Jean; Lin, Lih Y

    2007-05-01

    While 32 nm lithography technology is on the horizon for integrated circuit (IC) fabrication, matching the pace for miniaturization with optics has been hampered by the diffraction limit. However, development of nanoscale components and guiding methods is burgeoning through advances in fabrication techniques and materials processing. As waveguiding presents the fundamental issue and cornerstone for ultra-high density photonic ICs, we examine the current state of methods in the field. Namely, plasmonic, metal slot and negative dielectric based waveguides as well as a few sub-micrometer techniques such as nanoribbons, high-index contrast and photonic crystals waveguides are investigated in terms of construction, transmission, and limitations. Furthermore, we discuss in detail quantum dot (QD) arrays as a gain-enabled and flexible means to transmit energy through straight paths and sharp bends. Modeling, fabrication and test results are provided and show that the QD waveguide may be effective as an alternate means to transfer light on sub-diffraction dimensions.

  14. Methods for forming particles

    Energy Technology Data Exchange (ETDEWEB)

    Fox, Robert V.; Zhang, Fengyan; Rodriguez, Rene G.; Pak, Joshua J.; Sun, Chivin

    2016-06-21

    Single source precursors or pre-copolymers of single source precursors are subjected to microwave radiation to form particles of a I-III-VI.sub.2 material. Such particles may be formed in a wurtzite phase and may be converted to a chalcopyrite phase by, for example, exposure to heat. The particles in the wurtzite phase may have a substantially hexagonal shape that enables stacking into ordered layers. The particles in the wurtzite phase may be mixed with particles in the chalcopyrite phase (i.e., chalcopyrite nanoparticles) that may fill voids within the ordered layers of the particles in the wurtzite phase thus produce films with good coverage. In some embodiments, the methods are used to form layers of semiconductor materials comprising a I-III-VI.sub.2 material. Devices such as, for example, thin-film solar cells may be fabricated using such methods.

  15. Methods for forming particles

    Science.gov (United States)

    Fox, Robert V.; Zhang, Fengyan; Rodriguez, Rene G.; Pak, Joshua J.; Sun, Chivin

    2016-06-21

    Single source precursors or pre-copolymers of single source precursors are subjected to microwave radiation to form particles of a I-III-VI.sub.2 material. Such particles may be formed in a wurtzite phase and may be converted to a chalcopyrite phase by, for example, exposure to heat. The particles in the wurtzite phase may have a substantially hexagonal shape that enables stacking into ordered layers. The particles in the wurtzite phase may be mixed with particles in the chalcopyrite phase (i.e., chalcopyrite nanoparticles) that may fill voids within the ordered layers of the particles in the wurtzite phase thus produce films with good coverage. In some embodiments, the methods are used to form layers of semiconductor materials comprising a I-III-VI.sub.2 material. Devices such as, for example, thin-film solar cells may be fabricated using such methods.

  16. The random projection method

    CERN Document Server

    Vempala, Santosh S

    2005-01-01

    Random projection is a simple geometric technique for reducing the dimensionality of a set of points in Euclidean space while preserving pairwise distances approximately. The technique plays a key role in several breakthrough developments in the field of algorithms. In other cases, it provides elegant alternative proofs. The book begins with an elementary description of the technique and its basic properties. Then it develops the method in the context of applications, which are divided into three groups. The first group consists of combinatorial optimization problems such as maxcut, graph coloring, minimum multicut, graph bandwidth and VLSI layout. Presented in this context is the theory of Euclidean embeddings of graphs. The next group is machine learning problems, specifically, learning intersections of halfspaces and learning large margin hypotheses. The projection method is further refined for the latter application. The last set consists of problems inspired by information retrieval, namely, nearest neig...

  17. Glycoconjugates and methods

    Energy Technology Data Exchange (ETDEWEB)

    Bertozzi, Carolyn C. (Albany, CA); Yarema, Kevin J. (Albany, CA); Mahal; Lara K. (Berkeley, CA)

    2008-04-01

    Methods for making the functionalized glycoconjugates include (a) contacting a cell with a first monosaccharide, and (b) incubating the cell under conditions whereby the cell (i) internalizes the first monosaccharide, (ii) biochemically processes the first monosaccharide into a second saccharide, (iii) conjugates the saccharide to a carrier to form a glycoconjugate, and (iv) extracellularly expresses the glycoconjugate to form an extracellular glycoconjugate comprising a selectively reactive functional group. Methods for forming products at a cell further comprise contacting the functional group of the extracellularly expressed glycoconjugate with an agent which selectively reacts with the functional group to form a product. Subject compositions include cyto-compatible monosaccharides comprising a nitrogen or ether linked functional group selectively reactive at a cell surface and compositions and cells comprising such saccharides.

  18. Statistical Methods for Astronomy

    CERN Document Server

    Feigelson, Eric D

    2012-01-01

    This review outlines concepts of mathematical statistics, elements of probability theory, hypothesis tests and point estimation for use in the analysis of modern astronomical data. Least squares, maximum likelihood, and Bayesian approaches to statistical inference are treated. Resampling methods, particularly the bootstrap, provide valuable procedures when distributions functions of statistics are not known. Several approaches to model selection and good- ness of fit are considered. Applied statistics relevant to astronomical research are briefly discussed: nonparametric methods for use when little is known about the behavior of the astronomical populations or processes; data smoothing with kernel density estimation and nonparametric regression; unsupervised clustering and supervised classification procedures for multivariate problems; survival analysis for astronomical datasets with nondetections; time- and frequency-domain times series analysis for light curves; and spatial statistics to interpret the spati...

  19. MIXED METHOD RESEARCH

    Directory of Open Access Journals (Sweden)

    Masrizal Masrizal

    2012-03-01

    Full Text Available Mixed Method Research adalah metode penelitian yang diaplikasikan bila peneliti memiliki pertanyaan yang perlu diuji dari segi outcomes dan prosesnya, serta menyangkut kombinasi antara metode kuantitatif dan kualitatif dalam satu penelitian. Karena berfokus pada outcomes dan proses, maka desain MMR biasa digunakan dalam penelitian evaluasi program. Namun sekarang, MMR sudah sering digunakan untuk ilmu-ilmu sosial, seperti: konseling, psikologi social manajemen, dan pengorganisasian perilaku.

  20. MIXED METHOD RESEARCH

    OpenAIRE

    Masrizal Masrizal

    2012-01-01

    Mixed Method Research adalah metode penelitian yang diaplikasikan bila peneliti memiliki pertanyaan yang perlu diuji dari segi outcomes dan prosesnya, serta menyangkut kombinasi antara metode kuantitatif dan kualitatif dalam satu penelitian. Karena berfokus pada outcomes dan proses, maka desain MMR biasa digunakan dalam penelitian evaluasi program. Namun sekarang, MMR sudah sering digunakan untuk ilmu-ilmu sosial, seperti: konseling, psikologi social manajemen, dan pengorganisasian perilaku.

  1. Method for scavenging mercury

    Science.gov (United States)

    Chang, Shih-ger; Liu, Shou-heng; Liu, Zhao-rong; Yan, Naiqiang

    2009-01-20

    Disclosed herein is a method for removing mercury from a gas stream comprising contacting the gas stream with a getter composition comprising bromine, bromochloride, sulphur bromide, sulphur dichloride or sulphur monochloride and mixtures thereof. In one preferred embodiment the getter composition is adsorbed onto a sorbent. The sorbent may be selected from the group consisting of flyash, limestone, lime, calcium sulphate, calcium sulfite, activated carbon, charcoal, silicate, alumina and mixtures thereof. Preferred is flyash, activated carbon and silica.

  2. Statokinesigram normalization method.

    Science.gov (United States)

    de Oliveira, José Magalhães

    2017-02-01

    Stabilometry is a technique that aims to study the body sway of human subjects, employing a force platform. The signal obtained from this technique refers to the position of the foot base ground-reaction vector, known as the center of pressure (CoP). The parameters calculated from the signal are used to quantify the displacement of the CoP over time; there is a large variability, both between and within subjects, which prevents the definition of normative values. The intersubject variability is related to differences between subjects in terms of their anthropometry, in conjunction with their muscle activation patterns (biomechanics); and the intrasubject variability can be caused by a learning effect or fatigue. Age and foot placement on the platform are also known to influence variability. Normalization is the main method used to decrease this variability and to bring distributions of adjusted values into alignment. In 1996, O'Malley proposed three normalization techniques to eliminate the effect of age and anthropometric factors from temporal-distance parameters of gait. These techniques were adopted to normalize the stabilometric signal by some authors. This paper proposes a new method of normalization of stabilometric signals to be applied in balance studies. The method was applied to a data set collected in a previous study, and the results of normalized and nonnormalized signals were compared. The results showed that the new method, if used in a well-designed experiment, can eliminate undesirable correlations between the analyzed parameters and the subjects' characteristics and show only the experimental conditions' effects.

  3. Comments on PDF methods

    Science.gov (United States)

    Chen, J.-Y.

    1992-01-01

    Viewgraphs are presented on the following topics: the grand challenge of combustion engineering; research of probability density function (PDF) methods at Sandia; experiments of turbulent jet flames (Masri and Dibble, 1988); departures from chemical equilibrium; modeling turbulent reacting flows; superequilibrium OH radical; pdf modeling of turbulent jet flames; scatter plot for CH4 (methane) and O2 (oxygen); methanol turbulent jet flames; comparisons between predictions and experimental data; and turbulent C2H4 jet flames.

  4. Situational method engineering

    CERN Document Server

    Henderson-Sellers, Brian; Ågerfalk, Pär J; Rossi, Matti

    2014-01-01

    While previously available methodologies for software ? like those published in the early days of object technology ? claimed to be appropriate for every conceivable project, situational method engineering (SME) acknowledges that most projects typically have individual characteristics and situations. Thus, finding the most effective methodology for a particular project needs specific tailoring to that situation. Such a tailored software development methodology needs to take into account all the bits and pieces needed for an organization to develop software, including the software process, the

  5. Polymer compositions and methods

    Energy Technology Data Exchange (ETDEWEB)

    Allen, Scott D.; Willkomm, Wayne R.

    2016-09-27

    The present invention encompasses polyurethane compositions comprising aliphatic polycarbonate chains. In one aspect, the present invention encompasses polyurethane foams, thermoplastics and elastomers derived from aliphatic polycarbonate polyols and polyisocyanates wherein the polyol chains contain a primary repeating unit having a structure: ##STR00001## In another aspect, the invention provides articles comprising the inventive foam and elastomer compositions as well as methods of making such compositions.

  6. Nearshore Pipeline Installation Methods.

    Science.gov (United States)

    1981-08-01

    179. 5. Aldridge, R. G., and Bomba , J. G., "Deep Water Pipelines - Interdependence of Design and Construction", ASCE Paper. 6. American Society Civil...October 13, 1967. 24. Bomba , J. G. and Seeds, K. J., "Pipelining in 600 feet of water .... A Case Study of Washington Natural Gas Company’s Puget Sound...Crossing", Offshore Technology Conference, paper OTC 1188, 1970. 25. Bomba , J., "Submarine Pipe Construction Methods", Petroleum Engineer, Vol. 32

  7. Methods in Bioengineering

    CERN Document Server

    Rege, Kaushal

    2009-01-01

    Filling a critical gap in the current literature, this new resource presents practical, step-by-step methods to help you synthesize, characterize, biofunctionalize and apply the nanomaterial that is most suitable for handling a given nanoscale bioengineering problem. Written and presented by leading scientists and engineers in their respective fields, the authors offer a clear and detailed understanding of how to carry out nanoparticle functionalization with biomolecules (including enzymes), nanoparticle analysis and characterization, in vitro evaluation of nanoparticles using different cell l

  8. Method of infusion extraction

    Science.gov (United States)

    Chang-Diaz, Franklin R. (Inventor)

    1989-01-01

    Apparatus and method of removing desirable constituents from an infusible material by infusion extraction, where a piston operating in a first chamber draws a solvent into the first chamber where it may be heated, and then moves the heated solvent into a second chamber containing the infusible material, and where infusion extraction takes place. The piston then moves the solvent containing the extract through a filter into the first chamber, leaving the extraction residue in the second chamber.

  9. Method for detecting biomolecules

    Science.gov (United States)

    Huo, Qisheng; Liu, Jun

    2008-08-12

    A method for detecting and measuring the concentration of biomolecules in solution, utilizing a conducting electrode in contact with a solution containing target biomolecules, with a film with controllable pore size distribution characteristics applied to at least one surface of the conducting electrode. The film is functionalized with probe molecules that chemically interact with the target biomolecules at the film surface, blocking indicator molecules present in solution from diffusing from the solution to the electrode, thereby changing the electrochemical response of the electrode

  10. Method for scavenging mercury

    Science.gov (United States)

    Chang, Shih-ger; Liu, Shou-heng; Liu, Zhao-rong; Yan, Naiqiang

    2010-07-13

    Disclosed herein is a method for removing mercury from a gas stream comprising contacting the gas stream with a getter composition comprising bromine, bromochloride, sulphur bromide, sulphur dichloride or sulphur monochloride and mixtures thereof. In one preferred embodiment the getter composition is adsorbed onto a sorbent. The sorbent may be selected from the group consisting flyash, limestone, lime, calcium sulphate, calcium sulfite, activated carbon, charcoal, silicate, alumina and mixtures thereof. Preferred is flyash, activated carbon and silica.

  11. Method of producing imines

    Science.gov (United States)

    Sithambaram, Shanthakumar; Son, Young-Chan; Suib, Steven L.

    2008-04-08

    A method for forming an imine comprises reacting a first reactant comprising a hydroxyl functionality, a carbonyl functionality, or both a hydroxyl functionality and a carbonyl functionality with a second reactant having an amine functionality in the presence of ordered porous manganese-based octahedral molecular sieves and an oxygen containing gas at a temperature and for a time sufficient for the imine to be produced.

  12. Methods in Bioengineering

    CERN Document Server

    Zahn, Jeffrey D

    2009-01-01

    This unique volume presents leading-edge microfluidics methods used to handle, manipulate, and analyze cells, particles, and biological components (e.g., proteins and DNA) for microdiagnostics. The authors offer clear and detailed guidance on microfabrication techniques utilized to create microfluidic devices and on-chip flow control and mixing Microsystems, protein and DNA handling devices for electrophoretic and isoelectric separations in microchromatography columns, microfluidic manipulations of droplets via electrowetting and particles via dielectrophoresis for separations and chemical rea

  13. Chromosome doubling method

    Science.gov (United States)

    Kato, Akio

    2006-11-14

    The invention provides methods for chromosome doubling in plants. The technique overcomes the low yields of doubled progeny associated with the use of prior techniques for doubling chromosomes in plants such as grasses. The technique can be used in large scale applications and has been demonstrated to be highly effective in maize. Following treatment in accordance with the invention, plants remain amenable to self fertilization, thereby allowing the efficient isolation of doubled progeny plants.

  14. Montessori Method and ICTs

    OpenAIRE

    Athanasios Drigas; Eugenia Gkeka

    2016-01-01

    This article bridges the gap between the Montessori Method and Information and Communication Technologies (ICTs) in contemporary education. It reviews recent research works which recall the Montessori philosophy, principles and didactical tools applying to today’s computers and supporting technologies in children’s learning process. This article reviews how important the stimulation of human senses in the learning process is, as well as the development of Montessori materials using the body a...

  15. Geometrical method of decoupling

    Science.gov (United States)

    Baumgarten, C.

    2012-12-01

    The computation of tunes and matched beam distributions are essential steps in the analysis of circular accelerators. If certain symmetries—like midplane symmetry—are present, then it is possible to treat the betatron motion in the horizontal, the vertical plane, and (under certain circumstances) the longitudinal motion separately using the well-known Courant-Snyder theory, or to apply transformations that have been described previously as, for instance, the method of Teng and Edwards. In a preceding paper, it has been shown that this method requires a modification for the treatment of isochronous cyclotrons with non-negligible space charge forces. Unfortunately, the modification was numerically not as stable as desired and it was still unclear, if the extension would work for all conceivable cases. Hence, a systematic derivation of a more general treatment seemed advisable. In a second paper, the author suggested the use of real Dirac matrices as basic tools for coupled linear optics and gave a straightforward recipe to decouple positive definite Hamiltonians with imaginary eigenvalues. In this article this method is generalized and simplified in order to formulate a straightforward method to decouple Hamiltonian matrices with eigenvalues on the real and the imaginary axis. The decoupling of symplectic matrices which are exponentials of such Hamiltonian matrices can be deduced from this in a few steps. It is shown that this algebraic decoupling is closely related to a geometric “decoupling” by the orthogonalization of the vectors E→, B→, and P→, which were introduced with the so-called “electromechanical equivalence.” A mathematical analysis of the problem can be traced down to the task of finding a structure-preserving block diagonalization of symplectic or Hamiltonian matrices. Structure preservation means in this context that the (sequence of) transformations must be symplectic and hence canonical. When used iteratively, the decoupling

  16. Electron cryomicroscopy methods.

    Science.gov (United States)

    Unger, V M

    2001-10-01

    Electron cryomicroscopy methods comprise a rapidly expanding field providing insights into the structure and function of biological macromolecules and their supramolecular assemblies. The 3.8 A resolution structure of the membrane protein aquaporin, a view of the herpesvirus capsid at 8.5 A and the 10 A resolution structure of the spliceosomal U1 small nuclear ribonucleoprotein complex are three outstanding examples emphasizing the versatility of this technique.

  17. Method for making nanomaterials

    Science.gov (United States)

    Fan, Hongyou; Wu, Huimeng

    2013-06-04

    A method of making a nanostructure by preparing a face centered cubic-ordered metal nanoparticle film from metal nanoparticles, such as gold and silver nanoparticles, exerting a hydrostatic pressure upon the film at pressures of several gigapascals, followed by applying a non-hydrostatic stress perpendicularly at a pressure greater than approximately 10 GPA to form an array of nanowires with individual nanowires having a relatively uniform length, average diameter and density.

  18. Bering Mission Navigation Method

    OpenAIRE

    2003-01-01

    "Bering", after the name of the famous Danish explorer, is a near Earth object (NEO) and main belt asteroids mapping mission envisaged by a consortium of Danish universities and research institutes. To achieve the ambitious goals set forth by this mission, while containing the costs and risks, "Bering" sports several new technological enhancements and advanced instruments under development at the Technical University of Denmark (DTU). The autonomous on-board orbit determination method is part...

  19. Methods of celestial mechanics

    CERN Document Server

    Brouwer, Dirk

    2013-01-01

    Methods of Celestial Mechanics provides a comprehensive background of celestial mechanics for practical applications. Celestial mechanics is the branch of astronomy that is devoted to the motions of celestial bodies. This book is composed of 17 chapters, and begins with the concept of elliptic motion and its expansion. The subsequent chapters are devoted to other aspects of celestial mechanics, including gravity, numerical integration of orbit, stellar aberration, lunar theory, and celestial coordinates. Considerable chapters explore the principles and application of various mathematical metho

  20. ARK methods: some recent developments

    Science.gov (United States)

    Moir, Nicolette

    2005-03-01

    Almost Runge-Kutta methods are a sub-class of the family of methods known as general linear methods, used for solving ordinary differential equations. They combine many of the favourable properties of traditional Runge-Kutta methods with some additional advantages. We will introduce these methods, concentrating on methods of order four, and present some recent results.

  1. Multigrid methods III

    CERN Document Server

    Trottenberg, U; Third European Conference on Multigrid Methods

    1991-01-01

    These proceedings contain a selection of papers presented at the Third European Conference on Multigrid Methods which was held in Bonn on October 1-4, 1990. Following conferences in 1981 and 1985, a platform for the presentation of new Multigrid results was provided for a third time. Multigrid methods no longer have problems being accepted by numerical analysts and users of numerical methods; on the contrary, they have been further developed in such a successful way that they have penetrated a variety of new fields of application. The high number of 154 participants from 18 countries and 76 presented papers show the need to continue the series of the European Multigrid Conferences. The papers of this volume give a survey on the current Multigrid situation; in particular, they correspond to those fields where new developments can be observed. For example, se­ veral papers study the appropriate treatment of time dependent problems. Improvements can also be noticed in the Multigrid approach for semiconductor eq...

  2. Stochastic Methods in Biology

    CERN Document Server

    Kallianpur, Gopinath; Hida, Takeyuki

    1987-01-01

    The use of probabilistic methods in the biological sciences has been so well established by now that mathematical biology is regarded by many as a distinct dis­ cipline with its own repertoire of techniques. The purpose of the Workshop on sto­ chastic methods in biology held at Nagoya University during the week of July 8-12, 1985, was to enable biologists and probabilists from Japan and the U. S. to discuss the latest developments in their respective fields and to exchange ideas on the ap­ plicability of the more recent developments in stochastic process theory to problems in biology. Eighteen papers were presented at the Workshop and have been grouped under the following headings: I. Population genetics (five papers) II. Measure valued diffusion processes related to population genetics (three papers) III. Neurophysiology (two papers) IV. Fluctuation in living cells (two papers) V. Mathematical methods related to other problems in biology, epidemiology, population dynamics, etc. (six papers) An important f...

  3. Validation of analytical methods

    Directory of Open Access Journals (Sweden)

    Xavier Rius, F.

    2002-03-01

    Full Text Available In this paper we shall discuss the concept of method validation, describe the various elements and explain its close relationship with fitness for purpose. Method validation is based on the assumption that a series of requirements are fulfilled and we shall explain how these requirements are selected, the way in which evidence is supplied and what work has to be carried out in the laboratory. The basic principles of method validation and the different ways to validate a methodology, by inter-laboratory comparison or performing an in-house validation, are also described.En este artículo se discute el concepto de validación del método, se describen los elementos que la componen y se explica la fuerte relación entre la validación y las características de ajuste. El método de validación se basa en el cumplimiento de una serie de requerimientos, se explica como seleccionar esos requerimientos, la forma en que se suministran evidencias, y que trabajo se debe llevar a cabo en el laboratorio. También se describen, los principios básicos del método de validación y los diferentes caminos para validar una metodología, tanto en la comparación entre laboratorios o como cuando se lleva a cabo una validación dentro del laboratorio.

  4. Generalized Agile Estimation Method

    Directory of Open Access Journals (Sweden)

    Shilpa Bahlerao

    2011-01-01

    Full Text Available Agile cost estimation process always possesses research prospects due to lack of algorithmic approaches for estimating cost, size and duration. Existing algorithmic approach i.e. Constructive Agile Estimation Algorithm (CAEA is an iterative estimation method that incorporates various vital factors affecting the estimates of the project. This method has lots of advantages but at the same time has some limitations also. These limitations may due to some factors such as number of vital factors and uncertainty involved in agile projects etc. However, a generalized agile estimation may generate realistic estimates and eliminates the need of experts. In this paper, we have proposed iterative Generalized Estimation Method (GEM and presented algorithm based on it for agile with case studies. GEM  based algorithm various project domain classes and vital factors with prioritization level. Further, it incorporates uncertainty factor to quantify the risk of project for estimating cost, size and duration. It also provides flexibility to project managers for deciding on number of vital factors, uncertainty level and project domains thereby maintaining the agility.

  5. A practical MRI technique for detecting Abdominal Aorta Aneurism and Peripheral Arterial Disease

    Directory of Open Access Journals (Sweden)

    Aykut Aktas

    2014-12-01

    Full Text Available Aim: Peripheral Arterial Disease(PAD and abdominal aorta aneurysm(AAA are frequent problems in geriatric population. In DSA, CTA or MRA techniques contrast agents has to be used for diagnosis that can be nephrotoxic for elderly patients. Magnetic resonans imaging (MRI is the most powerful, non-ionising radiological diagnostic tool that has the highest soft tissue contrast resolution. The aim of our study was to investigate the effectivity of MRI by the means of detecting the AAA and PAD in comparison with DSA. Material and Method: After getting ethical commitee approvel and informed consent, we have performed Balanced turbo field echo(B-TFE MRI technique without contrast agent in 1.5 Tesla MRI device before DSA examination. The luminal diameters of renal arteries, infrarenal abdominal aorta, iliac and femoral arteries was measured by using Philips DICOM Viewer R2.2 application. The intraclass corelation coefficient and reliability used to check if the techniques could be used for each other and the t-test was used to measure the differences between them. Results: There has been a high relationship between B-TFE and DSA in detecting the pathologies of larger arteries like aorta. In the case of small arterial pathologies, there is relatively lower relationship between BTFE and DSA. Discussion: For the diagnosis of AAA and PAD, DSA is the gold standart technique but it is invasive and patients have radiation exposure. In the follow up of geriatric patients with larger arterial pathologies B-TFE can be used instead of contrast enhanced MRA and invasive DSA.

  6. Diagnostic Pitfalls in Postinterventional Intraarterial Magnetic Resonance Angiography after Recanalization of Femoropopliteal Arterial Occlusions

    Energy Technology Data Exchange (ETDEWEB)

    Huegli, R.W.; Aschwanden, M.; Kos, S.; Rasmus, M.; Jaeger, K.; Jacob, A.L.; Bilecen, D. (Dept. of Radiology and Dept. of Angiology, Univ. Hospital of Basel, Basel (Switzerland))

    2008-12-15

    Background: Magnetic resonance (MR)-guided vascular interventions are of increasing interest, and, with the use of contrast-enhanced techniques, intraarterial contrast-enhanced MR angiography (ia-ce-MRA) competes with intraarterial digital subtraction angiography (ia-DSA) for the diagnostic evaluation of the infrainguinal vessel tree. Purpose: To assess the diagnostic value of ia-ce-MRA and high-resolution T1-weighted (hr-T1w) imaging compared to the gold-standard ia-DSA for residual stenosis and local dissections after femoropopliteal recanalization in patients with peripheral arterial occlusive disease (PAOD). Material and Methods: Eight patients with PAOD and short vessel occlusion of their femoropopliteal arteries underwent recanalization and balloon positioning under DSA. Patients were transferred to a short-bore MR scanner. Percutaneous transluminal angioplasty (PTA) was accomplished under MR fluoroscopy. Pre- and postinterventional ia-ce three-dimensional (3D) gradient-echo MRA with gadopentate dimeglumine was performed using the intraarterial introducer sheath. Maximum intensity projections (MIP) and multiplanar reconstructions (MPR) were calculated from the data set. High-resolution T1w images of the angioplasty region before and after dilatation were acquired. Control ia-DSA images were obtained. Results: The postinterventional angioplasty results for stenosis grading were comparable in ia-MRA and ia-DSA. Only two of five local dissections in ia-DSA were visualized with the ia-ce-MRA runs including MIPs and MPRs. To clearly depict dissection, hr-T1w images were needed. Conclusion: Grading of stenotic lesions with ia-ce-MRA after PTA is comparable to ia-DSA. Intraarterial ce-MRA with calculated MIPs and MPRs is only partially sufficient to visualize local dissections after PTA. High-resolution T1w images are required for precise diagnosis of dissections in magnetic resonance tomography

  7. Diagnostic Pitfalls in Postinterventional Intraarterial Magnetic Resonance Angiography after Recanalization of Femoropopliteal Arterial Occlusions

    Energy Technology Data Exchange (ETDEWEB)

    Huegli, R.W.; Aschwanden, M.; Kos, S.; Rasmus, M.; Jaeger, K.; Jacob, A.L.; Bilecen, D. [Dept. of Radiology and Dept. of Angiology, Univ. Hospital of Basel, Basel (Switzerland)

    2008-12-15

    Background: Magnetic resonance (MR)-guided vascular interventions are of increasing interest, and, with the use of contrast-enhanced techniques, intraarterial contrast-enhanced MR angiography (ia-ce-MRA) competes with intraarterial digital subtraction angiography (ia-DSA) for the diagnostic evaluation of the infrainguinal vessel tree. Purpose: To assess the diagnostic value of ia-ce-MRA and high-resolution T1-weighted (hr-T1w) imaging compared to the gold-standard ia-DSA for residual stenosis and local dissections after femoropopliteal recanalization in patients with peripheral arterial occlusive disease (PAOD). Material and Methods: Eight patients with PAOD and short vessel occlusion of their femoropopliteal arteries underwent recanalization and balloon positioning under DSA. Patients were transferred to a short-bore MR scanner. Percutaneous transluminal angioplasty (PTA) was accomplished under MR fluoroscopy. Pre- and postinterventional ia-ce three-dimensional (3D) gradient-echo MRA with gadopentate dimeglumine was performed using the intraarterial introducer sheath. Maximum intensity projections (MIP) and multiplanar reconstructions (MPR) were calculated from the data set. High-resolution T1w images of the angioplasty region before and after dilatation were acquired. Control ia-DSA images were obtained. Results: The postinterventional angioplasty results for stenosis grading were comparable in ia-MRA and ia-DSA. Only two of five local dissections in ia-DSA were visualized with the ia-ce-MRA runs including MIPs and MPRs. To clearly depict dissection, hr-T1w images were needed. Conclusion: Grading of stenotic lesions with ia-ce-MRA after PTA is comparable to ia-DSA. Intraarterial ce-MRA with calculated MIPs and MPRs is only partially sufficient to visualize local dissections after PTA. High-resolution T1w images are required for precise diagnosis of dissections in magnetic resonance tomography.

  8. Method Engineering: Engineering of Information Systems Development Methods and Tools

    NARCIS (Netherlands)

    Brinkkemper, J.N.; Brinkkemper, Sjaak

    1996-01-01

    This paper proposes the term method engineering for the research field of the construction of information systems development methods and tools. Some research issues in method engineering are identified. One major research topic in method engineering is discussed in depth: situational methods, i.e.

  9. The data embedding method

    Energy Technology Data Exchange (ETDEWEB)

    Sandford, M.T. II; Bradley, J.N.; Handel, T.G.

    1996-06-01

    Data embedding is a new steganographic method for combining digital information sets. This paper describes the data embedding method and gives examples of its application using software written in the C-programming language. Sandford and Handel produced a computer program (BMPEMBED, Ver. 1.51 written for IBM PC/AT or compatible, MS/DOS Ver. 3.3 or later) that implements data embedding in an application for digital imagery. Information is embedded into, and extracted from, Truecolor or color-pallet images in Microsoft{reg_sign} bitmap (.BMP) format. Hiding data in the noise component of a host, by means of an algorithm that modifies or replaces the noise bits, is termed {open_quote}steganography.{close_quote} Data embedding differs markedly from conventional steganography, because it uses the noise component of the host to insert information with few or no modifications to the host data values or their statistical properties. Consequently, the entropy of the host data is affected little by using data embedding to add information. The data embedding method applies to host data compressed with transform, or {open_quote}lossy{close_quote} compression algorithms, as for example ones based on discrete cosine transform and wavelet functions. Analysis of the host noise generates a key required for embedding and extracting the auxiliary data from the combined data. The key is stored easily in the combined data. Images without the key cannot be processed to extract the embedded information. To provide security for the embedded data, one can remove the key from the combined data and manage it separately. The image key can be encrypted and stored in the combined data or transmitted separately as a ciphertext much smaller in size than the embedded data. The key size is typically ten to one-hundred bytes, and it is in data an analysis algorithm.

  10. Data embedding method

    Science.gov (United States)

    Sandford, Maxwell T., II; Bradley, Jonathan N.; Handel, Theodore G.

    1996-01-01

    Data embedding is a new steganographic method for combining digital information sets. This paper describes the data embedding method and gives examples of its application using software written in the C-programming language. Sandford and Handel produced a computer program (BMPEMBED, Ver. 1.51 written for IBM PC/AT or compatible, MS/DOS Ver. 3.3 or later) that implements data embedding in an application for digital imagery. Information is embedded into, and extracted from, Truecolor or color-pallet images in MicrosoftTM bitmap (BMP) format. Hiding data in the noise component of a host, by means of an algorithm that modifies or replaces the noise bits, is termed `steganography.' Data embedding differs markedly from conventional steganography, because it uses the noise component of the host to insert information with few or no modifications to the host data values or their statistical properties. Consequently, the entropy of the host data is affected little by using data embedding to add information. The data embedding method applies to host data compressed with transform, or `lossy' compression algorithms, as for example ones based on discrete cosine transform and wavelet functions. Analysis of the host noise generates a key required for embedding and extracting the auxiliary data from the combined data. The key is stored easily in the combined data. Images without the key cannot be processed to extract the embedded information. To provide security for the embedded data, one can remove the key from the combined data and manage it separately. The image key can be encrypted and stored in the combined data or transmitted separately as a ciphertext much smaller in size than the embedded data. The key size is typically ten to one-hundred bytes, and it is derived from the original host data by an analysis algorithm.

  11. ZIRCONIUM PHOSPHATE ADSORPTION METHOD

    Science.gov (United States)

    Russell, E.R.; Adamson, A.S.; Schubert, J.; Boyd, G.E.

    1958-11-01

    A method is presented for separating plutonium values from fission product values in aqueous acidic solution. This is accomplished by flowing the solutlon containing such values through a bed of zirconium orthophosphate. Any fission products adsorbed can subsequently be eluted by washing the column with a solution of 2N HNO/sub 3/ and O.lN H/sub 3/PO/sub 4/. Plutonium values may subsequently be desorbed by contacting the column with a solution of 7N HNO/sub 3/ .

  12. Methods of graded rings

    CERN Document Server

    Nastasescu, Constantin

    2004-01-01

    The topic of this book, graded algebra, has developed in the past decade to a vast subject with new applications in noncommutative geometry and physics. Classical aspects relating to group actions and gradings have been complemented by new insights stemming from Hopf algebra theory. Old and new methods are presented in full detail and in a self-contained way. Graduate students as well as researchers in algebra, geometry, will find in this book a useful toolbox. Exercises, with hints for solution, provide a direct link to recent research publications. The book is suitable for courses on Master level or textbook for seminars.

  13. Control system design method

    Science.gov (United States)

    Wilson, David G [Tijeras, NM; Robinett, III, Rush D.

    2012-02-21

    A control system design method and concomitant control system comprising representing a physical apparatus to be controlled as a Hamiltonian system, determining elements of the Hamiltonian system representation which are power generators, power dissipators, and power storage devices, analyzing stability and performance of the Hamiltonian system based on the results of the determining step and determining necessary and sufficient conditions for stability of the Hamiltonian system, creating a stable control system based on the results of the analyzing step, and employing the resulting control system to control the physical apparatus.

  14. Calcium measurement methods

    Directory of Open Access Journals (Sweden)

    CarloAlberto Redi

    2010-09-01

    Full Text Available Rightly stressed by prof. Wolfgang Walz in the Preface to the series Neuromethods series, the “careful application of methods is probably the most important step in the process of scientific inquiry”. Thus, I strongly suggest to all those interested in calcium signaling and especially to the new-comers in the hot topic of neuroscience (which has so much space even in science-society debate for its implications in legal issues and in the judge-decision process to take profit from this so well edited book. I am saying this since prof. Verkhratsky and prof. Petersen......

  15. Methods of thermodynamics

    CERN Document Server

    Reiss, Howard

    1997-01-01

    Since there is no shortage of excellent general books on elementary thermodynamics, this book takes a different approach, focusing attention on the problem areas of understanding of concept and especially on the overwhelming but usually hidden role of ""constraints"" in thermodynamics, as well as on the lucid exposition of the significance, construction, and use (in the case of arbitrary systems) of the thermodynamic potential. It will be especially useful as an auxiliary text to be used along with any standard treatment.Unlike some texts, Methods of Thermodynamics does not use statistical m

  16. Geometrical method of decoupling

    Directory of Open Access Journals (Sweden)

    C. Baumgarten

    2012-12-01

    Full Text Available The computation of tunes and matched beam distributions are essential steps in the analysis of circular accelerators. If certain symmetries—like midplane symmetry—are present, then it is possible to treat the betatron motion in the horizontal, the vertical plane, and (under certain circumstances the longitudinal motion separately using the well-known Courant-Snyder theory, or to apply transformations that have been described previously as, for instance, the method of Teng and Edwards. In a preceding paper, it has been shown that this method requires a modification for the treatment of isochronous cyclotrons with non-negligible space charge forces. Unfortunately, the modification was numerically not as stable as desired and it was still unclear, if the extension would work for all conceivable cases. Hence, a systematic derivation of a more general treatment seemed advisable. In a second paper, the author suggested the use of real Dirac matrices as basic tools for coupled linear optics and gave a straightforward recipe to decouple positive definite Hamiltonians with imaginary eigenvalues. In this article this method is generalized and simplified in order to formulate a straightforward method to decouple Hamiltonian matrices with eigenvalues on the real and the imaginary axis. The decoupling of symplectic matrices which are exponentials of such Hamiltonian matrices can be deduced from this in a few steps. It is shown that this algebraic decoupling is closely related to a geometric “decoupling” by the orthogonalization of the vectors E[over →], B[over →], and P[over →], which were introduced with the so-called “electromechanical equivalence.” A mathematical analysis of the problem can be traced down to the task of finding a structure-preserving block diagonalization of symplectic or Hamiltonian matrices. Structure preservation means in this context that the (sequence of transformations must be symplectic and hence canonical. When

  17. Method of joining ceramics

    Science.gov (United States)

    Henager, Jr., Charles H.; Brimhall, John L.

    2000-01-01

    According to the method of the present invention, joining a first bi-element carbide to a second bi-element carbide, has the steps of: (a) forming a bond agent containing a metal carbide and silicon; (b) placing the bond agent between the first and second bi-element carbides to form a pre-assembly; and (c) pressing and heating the pre-assembly in a non-oxidizing atmosphere to a temperature effective to induce a displacement reaction creating a metal silicon phase bonding the first and second bi-element carbides.

  18. Object oriented methods

    CERN Document Server

    Graham, Ian

    1994-01-01

    This book is a revision of Ian Graham's successful survey of the whole area of object technology. It covers object- oriented programming, object-oriented design, object- oriented analysis, object-oriented databases and treats several related technologies. New to this edition are more applications of object-oriented methods and more coverage of object-oriented database products available. Graham has also doubled the design and analysis material that examines over 60 different approaches - making this the most comprehensive book on the market. Also new is the foreword by Grady Booch.

  19. Electrical estimating methods

    CERN Document Server

    Del Pico, Wayne J

    2014-01-01

    Simplify the estimating process with the latest data, materials, and practices Electrical Estimating Methods, Fourth Edition is a comprehensive guide to estimating electrical costs, with data provided by leading construction database RS Means. The book covers the materials and processes encountered by the modern contractor, and provides all the information professionals need to make the most precise estimate. The fourth edition has been updated to reflect the changing materials, techniques, and practices in the field, and provides the most recent Means cost data available. The complexity of el

  20. Introduction to Numerical Methods

    Energy Technology Data Exchange (ETDEWEB)

    Schoonover, Joseph A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-06-14

    These are slides for a lecture for the Parallel Computing Summer Research Internship at the National Security Education Center. This gives an introduction to numerical methods. Repetitive algorithms are used to obtain approximate solutions to mathematical problems, using sorting, searching, root finding, optimization, interpolation, extrapolation, least squares regresion, Eigenvalue problems, ordinary differential equations, and partial differential equations. Many equations are shown. Discretizations allow us to approximate solutions to mathematical models of physical systems using a repetitive algorithm and introduce errors that can lead to numerical instabilities if we are not careful.

  1. Epitope prediction methods

    DEFF Research Database (Denmark)

    Karosiene, Edita

    on machine learning techniques. Several MHC class I binding prediction algorithms have been developed and due to their high accuracy they are used by many immunologists to facilitate the conventional experimental process of epitope discovery. However, the accuracy of these methods depends on data defining...... the NetMHCIIpan-3.0 predictor based on artificial neural networks, which is capable of giving binding affinities to any human MHC class II molecule. Chapter 4 of this thesis gives an overview of bioinformatics tools developed by the Immunological Bioinformatics group at Center for Biological Sequence...

  2. Formal Methods in Industry

    Directory of Open Access Journals (Sweden)

    Alexei Serna A.

    2012-12-01

    Full Text Available The application of formal methods in industry has progressed extensively over the past decade and the results are promising. But despite these achievements and it have been documented in numerous studies, it is still very common the skepticism about its usefulness and applicability. The goal of this paper is to show that its evolution over the past decade exceeds all previous processes and each time they do a better job to satisfy industrial needs. This is achieved by the description of some experiments and the result of various applications in industry and through an analyzing of the needs of companies that must be satisfy the research community in this field.

  3. Interval methods: An introduction

    DEFF Research Database (Denmark)

    Achenie, L.E.K.; Kreinovich, V.; Madsen, Kaj

    2006-01-01

    This chapter contains selected papers presented at the Minisymposium on Interval Methods of the PARA'04 Workshop '' State-of-the-Art in Scientific Computing ''. The emphasis of the workshop was on high-performance computing (HPC). The ongoing development of ever more advanced computers provides....... An important characteristic of the computer performance in scientific computing is the accuracy of the Computation results. Often, we can estimate this accuracy by using traditional statistical techniques. However, in many practical situations, we do not know the probability distributions of different...... '' techniques, and the applications of these techniques to various problems of scientific computing....

  4. Hydraulic mining method

    Science.gov (United States)

    Huffman, Lester H.; Knoke, Gerald S.

    1985-08-20

    A method of hydraulically mining an underground pitched mineral vein comprising drilling a vertical borehole through the earth's lithosphere into the vein and drilling a slant borehole along the footwall of the vein to intersect the vertical borehole. Material is removed from the mineral vein by directing a high pressure water jet thereagainst. The resulting slurry of mineral fragments and water flows along the slant borehole into the lower end of the vertical borehole from where it is pumped upwardly through the vertical borehole to the surface.

  5. QUATERNIONIC JACOBI METHOD APPLICATIONS

    OpenAIRE

    SANCREY RODRIGUES ALVES

    2008-01-01

    O método tipo-Jacobi quaterniônico foi proposto em 1993. Vários estudos provaram sua convergência e melhoram a teoria proposta desde então. O presente trabalho realiza uma síntese do método tipo- Jacobi quaterniônico, apresentando aplicações do mesmo a diferentes tipos de matrizes. The quaternionic Jacobi method was proposed on 1993. Lots of studies has proved his convergence and also has improved the theory proposed. This document makes a survey of this me...

  6. Methods in Bioengineering

    CERN Document Server

    Nahmias, Yaakov

    2009-01-01

    Offering a practical look into the field, this volume presents the science behind microscale device design and the engineering of its fabrication. Supported with dozens of full-color illustrations, this book offers you clear, step-by-step methods for the cell capture from whole blood, high-throughput study of transcriptional dynamics in living cells, temporal control of cell-cell interaction, nanoscale measurements of cellular forces, immobilizing living c. elegans, optical and electrical on-chip cell sorting and human-on-chip modeling of drug metabolism.

  7. Interior-point methods

    Science.gov (United States)

    Potra, Florian A.; Wright, Stephen J.

    2000-12-01

    The modern era of interior-point methods dates to 1984, when Karmarkar proposed his algorithm for linear programming. In the years since then, algorithms and software for linear programming have become quite sophisticated, while extensions to more general classes of problems, such as convex quadratic programming, semi-definite programming, and nonconvex and nonlinear problems, have reached varying levels of maturity. We review some of the key developments in the area, including comments on both the complexity theory and practical algorithms for linear programming, semi-definite programming, monotone linear complementarity, and convex programming over sets that can be characterized by self-concordant barrier functions.

  8. Mathematical methods for physicists

    CERN Document Server

    Arfken, George B

    1985-01-01

    Mathematical Methods for Physicists, Third Edition provides an advanced undergraduate and beginning graduate study in physical science, focusing on the mathematics of theoretical physics. This edition includes sections on the non-Cartesian tensors, dispersion theory, first-order differential equations, numerical application of Chebyshev polynomials, the fast Fourier transform, and transfer functions. Many of the physical examples provided in this book, which are used to illustrate the applications of mathematics, are taken from the fields of electromagnetic theory and quantum mechanics. The He

  9. Crystallographic Lattice Boltzmann Method

    Science.gov (United States)

    Namburi, Manjusha; Krithivasan, Siddharth; Ansumali, Santosh

    2016-01-01

    Current approaches to Direct Numerical Simulation (DNS) are computationally quite expensive for most realistic scientific and engineering applications of Fluid Dynamics such as automobiles or atmospheric flows. The Lattice Boltzmann Method (LBM), with its simplified kinetic descriptions, has emerged as an important tool for simulating hydrodynamics. In a heterogeneous computing environment, it is often preferred due to its flexibility and better parallel scaling. However, direct simulation of realistic applications, without the use of turbulence models, remains a distant dream even with highly efficient methods such as LBM. In LBM, a fictitious lattice with suitable isotropy in the velocity space is considered to recover Navier-Stokes hydrodynamics in macroscopic limit. The same lattice is mapped onto a cartesian grid for spatial discretization of the kinetic equation. In this paper, we present an inverted argument of the LBM, by making spatial discretization as the central theme. We argue that the optimal spatial discretization for LBM is a Body Centered Cubic (BCC) arrangement of grid points. We illustrate an order-of-magnitude gain in efficiency for LBM and thus a significant progress towards feasibility of DNS for realistic flows. PMID:27251098

  10. Research methods in information

    CERN Document Server

    Pickard, Alison Jane

    2013-01-01

    The long-awaited 2nd edition of this best-selling research methods handbook is fully updated and includes brand new coverage of online research methods and techniques, mixed methodology and qualitative analysis. There is an entire chapter contributed by Professor Julie McLeod, Sue Childs and Elizabeth Lomas focusing on research data management, applying evidence from the recent JISC funded 'DATUM' project. The first to focus entirely on the needs of the information and communications community, it guides the would-be researcher through the variety of possibilities open to them under the heading "research" and provides students with the confidence to embark on their dissertations. The focus here is on the 'doing' and although the philosophy and theory of research is explored to provide context, this is essentially a practical exploration of the whole research process with each chapter fully supported by examples and exercises tried and tested over a whole teaching career. The book will take readers through eac...

  11. Nanoscale waveguiding methods

    Directory of Open Access Journals (Sweden)

    Wang Chia-Jean

    2007-01-01

    Full Text Available AbstractWhile 32 nm lithography technology is on the horizon for integrated circuit (IC fabrication, matching the pace for miniaturization with optics has been hampered by the diffraction limit. However, development of nanoscale components and guiding methods is burgeoning through advances in fabrication techniques and materials processing. As waveguiding presents the fundamental issue and cornerstone for ultra-high density photonic ICs, we examine the current state of methods in the field. Namely, plasmonic, metal slot and negative dielectric based waveguides as well as a few sub-micrometer techniques such as nanoribbons, high-index contrast and photonic crystals waveguides are investigated in terms of construction, transmission, and limitations. Furthermore, we discuss in detail quantum dot (QD arrays as a gain-enabled and flexible means to transmit energy through straight paths and sharp bends. Modeling, fabrication and test results are provided and show that the QD waveguide may be effective as an alternate means to transfer light on sub-diffraction dimensions.

  12. Recombinant methods and materials

    Energy Technology Data Exchange (ETDEWEB)

    Roizman, B.; Post, L.E.

    1988-09-06

    This patent describes a method for stably effecting the insertion or deletion of a selected DNA sequence at a specific site in a viral genome. The method consists of: (1) isolating from the genome a linear DNA fragment comprising both (a) the specific site determined for insertion or deletion of selected DNA sequence and (b) flanking DNA sequences normally preceding and following the site; (2) preparing first and second altered genome fragments from the fragment isolated in step (1). (a) the first altered fragment comprising the fragment comprising a thymidine kinase gene in a position intermediate the ends of the fragment, and (b) the second altered fragment comprising the fragment having the selected DNA sequence inserted therein or deleted therefrom; (3) contacting the genome with the first altered fragment under conditions permitting recombination at sites of DNA sequence homology, selecting for a recombinant genome comprising the thymidine kinase gene, and isolating the recombinant genome; and (4) contacting the recombinant genome isolated in step (3) with the second altered fragment under conditions permitting recombination at sites of DNA sequence homology, selecting for a recombinant genome lacking the thymidine kinase gene, and isolating the recombinant genome product.

  13. Methods of Endotoxin Detection.

    Science.gov (United States)

    Su, Wenqiong; Ding, Xianting

    2015-08-01

    Endotoxin, present in the outer membrane of all gram-negative bacteria, can pose serious risks to human health, from irreversible shock to death. Therefore, it is essential to develop sensitive, accurate, and rapid methods for its detection. The rabbit pyrogen test is the first standard technique for endotoxin detection and, nowadays, has been replaced by the Limulus Amoebocyte Lysate test, which is the most popular detection technique for endotoxin. With in-depth understanding of endotoxin, biosensors based on endotoxin-sensing components are promising alternatives to pursue in developing low-cost, easy-operation, and fast-response endotoxin detection techniques. This article summarizes the recent advances of endotoxin detection methods with a particular emphasis on optical and electrochemical biosensors based on various sensing elements ranging from nature biomolecules to artificial materials. As the research and technological revolution continues, the highly integrated and miniaturized commercial devices for sensitively and reliably detecting endotoxin will provide a wide range of applications in people's daily life.

  14. Conjugated polymer nanoparticles, methods of using, and methods of making

    KAUST Repository

    Habuchi, Satoshi

    2017-03-16

    Embodiments of the present disclosure provide for conjugated polymer nanoparticle, method of making conjugated polymer nanoparticles, method of using conjugated polymer nanoparticle, polymers, and the like.

  15. Microencapsulation system and method

    Science.gov (United States)

    Morrison, Dennis R. (Inventor)

    2009-01-01

    A microencapsulation apparatus is provided which is configured to form co-axial multi-lamellar microcapsules from materials discharged from first and second microsphere dispensers of the apparatus. A method of fabricating and processing microcapsules is also provided which includes forming distinct droplets comprising one or more materials and introducing the droplets directly into a solution bath to form a membrane around the droplets such that a plurality of microcapsules are formed. A microencapsulation system is provided which includes a microcapsule production unit, a fluidized passage for washing and harvesting microcapsules dispensed from the microcapsule production unit and a flow sensor for sizing and counting the microcapsules. In some embodiments, the microencapsulation system may further include a controller configured to simultaneously operate the microcapsule production unit, fluidized passage and flow sensor to process the microcapsules in a continuous manner.

  16. Introduction to perturbation methods

    CERN Document Server

    Holmes, M

    1995-01-01

    This book is an introductory graduate text dealing with many of the perturbation methods currently used by applied mathematicians, scientists, and engineers. The author has based his book on a graduate course he has taught several times over the last ten years to students in applied mathematics, engineering sciences, and physics. The only prerequisite for the course is a background in differential equations. Each chapter begins with an introductory development involving ordinary differential equations. The book covers traditional topics, such as boundary layers and multiple scales. However, it also contains material arising from current research interest. This includes homogenization, slender body theory, symbolic computing, and discrete equations. One of the more important features of this book is contained in the exercises. Many are derived from problems of up- to-date research and are from a wide range of application areas.

  17. Extending the MINLO method

    CERN Document Server

    Frederix, Rikkert

    2015-01-01

    We consider improving POWHEG+MINLO simulations, so as to also render them NLO accurate in the description of observables receiving contributions from events with lower parton multiplicity than present in their underlying NLO calculation. On a conceptual level we follow the strategy of the so-called MINLO' programs. Whereas the existing MINLO' framework requires explicit analytic input from higher order resummation, here we derive an effective numerical approximation to these ingredients, by imposing unitarity. This offers a way of extending the MINLO' method to more complex processes, complementary to the known route which uses explicit computations of high-accuracy resummation inputs. Specifically, we have focused on Higgs-plus-two-jet production (HJJ) and related processes. We also consider how one can cover three units of multiplicity at NLO accuracy, i.e. we consider how the HJJ-MINLO simulation may yield NLO accuracy for inclusive H, HJ, and HJJ quantities. We perform a feasibility study assessing the po...

  18. Data mining methods

    CERN Document Server

    Chattamvelli, Rajan

    2015-01-01

    DATA MINING METHODS, Second Edition discusses both theoretical foundation and practical applications of datamining in a web field including banking, e-commerce, medicine, engineering and management. This book starts byintroducing data and information, basic data type, data category and applications of data mining. The second chapterbriefly reviews data visualization technology and importance in data mining. Fundamentals of probability and statisticsare discussed in chapter 3, and novel algorithm for sample covariants are derived. The next two chapters give an indepthand useful discussion of data warehousing and OLAP. Decision trees are clearly explained and a new tabularmethod for decision tree building is discussed. The chapter on association rules discusses popular algorithms andcompares various algorithms in summary table form. An interesting application of genetic algorithm is introduced inthe next chapter. Foundations of neural networks are built from scratch and the back propagation algorithm is derived...

  19. New methods in cytogenetics.

    Science.gov (United States)

    Buckle, V J; Kearney, L

    1994-06-01

    Developments in the technique of fluorescence in situ hybridization (FISH) now permit hybridization of sequences ranging from 1 kb to whole genomes. The technique can be used in applications from coarse mapping of whole chromosomes to high-resolution analysis of extended strands of DNA. The complexity, and hence the coverage, of 'paints' prepared by amplification is being improved to the extent that such methods are used in cloning strategies for the generation of region-specific probes. Interphase analysis and comparative genomic hybridization are becoming important tools in cancer cytogenetics, and the potential for routine analysis of fetal cells obtained from maternal blood may provide a fresh approach to prenatal cytogenetic screening. Functional studies of gene activity and nuclear organization are now also possible.

  20. Electrochemical catalyst recovery method

    Science.gov (United States)

    Silva, Laura J.; Bray, Lane A.

    1995-01-01

    A method of recovering catalyst material from latent catalyst material solids includes: a) combining latent catalyst material solids with a liquid acid anolyte solution and a redox material which is soluble in the acid anolyte solution to form a mixture; b) electrochemically oxidizing the redox material within the mixture into a dissolved oxidant, the oxidant having a potential for oxidation which is effectively higher than that of the latent catalyst material; c) reacting the oxidant with the latent catalyst material to oxidize the latent catalyst material into at least one oxidized catalyst species which is soluble within the mixture and to reduce the oxidant back into dissolved redox material; and d) recovering catalyst material from the oxidized catalyst species of the mixture. The invention is expected to be particularly useful in recovering spent catalyst material from petroleum hydroprocessing reaction waste products having adhered sulfides, carbon, hydrocarbons, and undesired metals, and as well as in other industrial applications.

  1. Floating Silicon Method

    Energy Technology Data Exchange (ETDEWEB)

    Kellerman, Peter

    2013-12-21

    The Floating Silicon Method (FSM) project at Applied Materials (formerly Varian Semiconductor Equipment Associates), has been funded, in part, by the DOE under a “Photovoltaic Supply Chain and Cross Cutting Technologies” grant (number DE-EE0000595) for the past four years. The original intent of the project was to develop the FSM process from concept to a commercially viable tool. This new manufacturing equipment would support the photovoltaic industry in following ways: eliminate kerf losses and the consumable costs associated with wafer sawing, allow optimal photovoltaic efficiency by producing high-quality silicon sheets, reduce the cost of assembling photovoltaic modules by creating large-area silicon cells which are free of micro-cracks, and would be a drop-in replacement in existing high efficiency cell production process thereby allowing rapid fan-out into the industry.

  2. Cyclostationarity theory and methods

    CERN Document Server

    Leśkow, Jacek; Napolitano, Antonio; Sanchez-Ramirez, Andrea

    2014-01-01

    In the last decade the research in signal analysis was dominated by models that encompass nonstationarity as an important feature. This book presents the results of a workshop held in Grodek—Poland in February 2013 which was dedicated to the investigation of cyclostationary signals. Its main objective is to highlight the strong interactions between theory and applications of cyclostationary signals with the use of modern statistical tools. An important application of cyclostationary signals is the analysis of mechanical signals generated by a vibrating mechanism. Cyclostationary models are very important to perform basic operations on signals in both time and frequency domains. One of the fundamental problems in diagnosis of rotating machine is the identification of significant modulating frequencies that contribute to the cyclostationary nature of the signals. The book shows that there are modern tools available for analyzing cyclostationary signals without the assumption of gaussianity. Those methods are...

  3. METHOD OF RECOVERING THORIUM

    Science.gov (United States)

    Fisher, R.W.

    1957-12-10

    A method is described for recovering thorium from impurities found in a slag containing thorium and said impurities, comprising leaching a composition containing thorium with water, removing the water solution, treating the residue with hydrochloric acid, separating the solution from the insoluble residue, adjusting its acidity to 1 to 3 normal, adding oxalic acid, and thereafter separating the precipitated thorium oxalate digesting the residue from the hydrochloric acid treatment with a strong solution of sodium hydroxide at an elevated temperature, removing said solution and treating the insoluble residue with hydrochloric acid, separating the solution from the insoluble residue, adjusting the acidity of this solution to 1 to 3 normal, adding nitric acid to oxidize the iron present, adding oxalic acid and thereafter separating the thorium oxalate thus precipitated.

  4. Ticks and control methods.

    Science.gov (United States)

    Jongejan, F; Uilenberg, G

    1994-12-01

    Ticks are the most important ectoparasites of livestock in tropical and sub-tropical areas, and are responsible for severe economic losses both through the direct effects of blood sucking and indirectly as vectors of pathogens and toxins. Feeding by large numbers of ticks causes reduction in live weight gain and anaemia among domestic animals, while tick bites also reduce the quality of hides. However, the major losses caused by ticks are due to the ability to transmit protozoan, rickettsial and viral diseases of livestock, which are of great economic importance world-wide. The authors review general aspects of tick biology, the taxonomy, pathogenic effects and vector role of these species, and methods for the control of ticks. The distribution of ticks is continuously changing, as illustrated by the spread of the African tick Amblyomma variegatum in the Caribbean, where a large-scale eradication campaign is now under way.

  5. Radioactive air sampling methods

    CERN Document Server

    Maiello, Mark L

    2010-01-01

    Although the field of radioactive air sampling has matured and evolved over decades, it has lacked a single resource that assimilates technical and background information on its many facets. Edited by experts and with contributions from top practitioners and researchers, Radioactive Air Sampling Methods provides authoritative guidance on measuring airborne radioactivity from industrial, research, and nuclear power operations, as well as naturally occuring radioactivity in the environment. Designed for industrial hygienists, air quality experts, and heath physicists, the book delves into the applied research advancing and transforming practice with improvements to measurement equipment, human dose modeling of inhaled radioactivity, and radiation safety regulations. To present a wide picture of the field, it covers the international and national standards that guide the quality of air sampling measurements and equipment. It discusses emergency response issues, including radioactive fallout and the assets used ...

  6. Parametric lattice Boltzmann method

    Science.gov (United States)

    Shim, Jae Wan

    2017-06-01

    The discretized equilibrium distributions of the lattice Boltzmann method are presented by using the coefficients of the Lagrange interpolating polynomials that pass through the points related to discrete velocities and using moments of the Maxwell-Boltzmann distribution. The ranges of flow velocity and temperature providing positive valued distributions vary with regulating discrete velocities as parameters. New isothermal and thermal compressible models are proposed for flows of the level of the isothermal and thermal compressible Navier-Stokes equations. Thermal compressible shock tube flows are simulated by only five on-lattice discrete velocities. Two-dimensional isothermal and thermal vortices provoked by the Kelvin-Helmholtz instability are simulated by the parametric models.

  7. Method for radioactivity monitoring

    Science.gov (United States)

    Umbarger, C. John; Cowder, Leo R.

    1976-10-26

    The disclosure relates to a method for analyzing uranium and/or thorium contents of liquid effluents preferably utilizing a sample containing counting chamber. Basically, 185.7-keV gamma rays following .sup.235 U alpha decay to .sup.231 Th which indicate .sup.235 U content and a 63-keV gamma ray doublet found in the nucleus of .sup.234 Pa, a granddaughter of .sup.238 U, are monitored and the ratio thereof taken to derive uranium content and isotopic enrichment .sup.235 U/.sup.235 U + .sup.238 U) in the liquid effluent. Thorium content is determined by monitoring the intensity of 238-keV gamma rays from the nucleus of .sup.212 Bi in the decay chain of .sup.232 Th.

  8. Method for synthesizing HMX

    Science.gov (United States)

    McGuire, Raymond R.; Coon, Clifford L.; Harrar, Jackson E.; Pearson, Richard K.

    1984-01-01

    A method and apparatus for electrochemically synthesizing N.sub.2 O.sub.5 cludes oxidizing a solution of N.sub.2 O.sub.4 /HNO.sub.3 at an anode, while maintaining a controlled potential between the N.sub.2 O.sub.4 /HNO.sub.3 solution and the anode. A potential of about 1.35 to 2.0 V vs. SCE is preferred, while a potential of about 1.80 V vs. SCE is most preferred. Thereafter, the N.sub.2 O.sub.5 is reacted with either 1.5-diacetyl-3,7-dinitro-1,3,5,7-tetraazacyclooctane (DADN) or 1,3,5,7-tetraacetyl-1,3,5,7-tetraazacyclooctane (TAT) to form cyclotetramethylenetetraamine (HMX).

  9. The Algebraic Method

    CERN Document Server

    Grassi, P A; Steinhauser, M

    2001-01-01

    Combining the effect of an intermediate renormalization prescription (zero momentum subtraction) and the background field method (BFM), we show that the algebraic renormalization procedure needed for the computation of radiative corrections within non-invariant regularization schemes is drastically simplified. The present technique is suitable for gauge models and, here, is applied to the Standard Model. The use of the BFM allows a powerful organization of the counterterms and avoids complicated Slavnov-Taylor identities. Furthermore, the Becchi-Rouet-Stora-Tyutin (BRST) variation of background fields plays a special role in disentangling Ward-Takahashi identities (WTI) and Slavnov-Taylor identities (STI). Finally, the strategy to be applied to physical processes is exemplified for the process $b\\to s\\gamma$.

  10. Unconventional methods for clustering

    Science.gov (United States)

    Kotyrba, Martin

    2016-06-01

    Cluster analysis or clustering is a task of grouping a set of objects in such a way that objects in the same group (called a cluster) are more similar (in some sense or another) to each other than to those in other groups (clusters). It is the main task of exploratory data mining and a common technique for statistical data analysis used in many fields, including machine learning, pattern recognition, image analysis, information retrieval, and bioinformatics. The topic of this paper is one of the modern methods of clustering namely SOM (Self Organising Map). The paper describes the theory needed to understand the principle of clustering and descriptions of algorithm used with clustering in our experiments.

  11. Dominant modal decomposition method

    Science.gov (United States)

    Dombovari, Zoltan

    2017-03-01

    The paper deals with the automatic decomposition of experimental frequency response functions (FRF's) of mechanical structures. The decomposition of FRF's is based on the Green function representation of free vibratory systems. After the determination of the impulse dynamic subspace, the system matrix is formulated and the poles are calculated directly. By means of the corresponding eigenvectors, the contribution of each element of the impulse dynamic subspace is determined and the sufficient decomposition of the corresponding FRF is carried out. With the presented dominant modal decomposition (DMD) method, the mode shapes, the modal participation vectors and the modal scaling factors are identified using the decomposed FRF's. Analytical example is presented along with experimental case studies taken from machine tool industry.

  12. Method for maskless lithography

    Science.gov (United States)

    Sweatt, William C.; Stulen, Richard H.

    2000-01-01

    The present invention provides a method for maskless lithography. A plurality of individually addressable and rotatable micromirrors together comprise a two-dimensional array of micromirrors. Each micromirror in the two-dimensional array can be envisioned as an individually addressable element in the picture that comprises the circuit pattern desired. As each micromirror is addressed it rotates so as to reflect light from a light source onto a portion of the photoresist coated wafer thereby forming a pixel within the circuit pattern. By electronically addressing a two-dimensional array of these micromirrors in the proper sequence a circuit pattern that is comprised of these individual pixels can be constructed on a microchip. The reflecting surface of the micromirror is configured in such a way as to overcome coherence and diffraction effects in order to produce circuit elements having straight sides.

  13. Geophysical Methods: an Overview

    Science.gov (United States)

    Becker, A.; Goldstein, N. E.; Lee, K. H.; Majer, E. L.; Morrison, H. F.; Myer, L.

    1992-01-01

    Geophysics is expected to have a major role in lunar resource assessment when manned systems return to the Moon. Geophysical measurements made from a lunar rover will contribute to a number of key studies: estimating regolith thickness, detection of possible large-diameter lava tubes within maria basalts, detection of possible subsurface ice in polar regions, detection of conductive minerals that formed directly from a melt (orthomagmatic sulfides of Cu, Ni, Co), and mapping lunar geology beneath the regolith. The techniques that can be used are dictated both by objectives and by our abilities to adapt current technology to lunar conditions. Instrument size, weight, power requirements, and freedom from orientation errors are factors we have considered. Among the geophysical methods we believe to be appropriate for a lunar resource assessment are magnetics, including gradiometry, time-domain magnetic induction, ground-penetrating radar, seismic reflection, and gravimetry.

  14. Mathematical methods in engineering

    CERN Document Server

    Machado, José

    2014-01-01

    This book presents a careful selection of the contributions presented at the Mathematical Methods in Engineering (MME10) International Symposium, held at the Polytechnic Institute of Coimbra- Engineering Institute of Coimbra (IPC/ISEC), Portugal, October 21-24, 2010. The volume discusses recent developments about theoretical and applied mathematics toward the solution of engineering problems, thus covering a wide range of topics, such as:  Automatic Control, Autonomous Systems, Computer Science, Dynamical Systems and Control,  Electronics, Finance and Economics, Fluid Mechanics and Heat Transfer, Fractional Mathematics, Fractional Transforms and Their Applications,  Fuzzy Sets and Systems, Image and Signal Analysis, Image Processing, Mechanics, Mechatronics, Motor Control and Human Movement Analysis, Nonlinear Dynamics, Partial Differential Equations, Robotics, Acoustics, Vibration and Control, and Wavelets.

  15. Remanufacturability and Assessment Method

    Institute of Scientific and Technical Information of China (English)

    ZHU Sheng; CUI Pei-zhi; YAO Ju-kun

    2004-01-01

    Remanufacturing represents the combination of "three Rs" (reduce, reuse, recycle) into a single activity, which restores a wide variety of worn-out, discarded durable products to like-new condition, prolonging theit useful life,protecting the environment. The application of surface engineering has promoted the development of remanufacturing.Remanufacturing is an environmentally and economically sound way to achieve many of the goals of sustainable development. Through developing study of product design for remanufacturing, it can promote the surface technologies application in the remanufacturing, and markedly enhance the efficiency of remanufacturing. This paper gives some relative concepts about product design for remanufacturing, such as remanufacturability, and brings forward the remanufacturability research contents and assessment method of used product.

  16. Acoustophoresis separation method

    Science.gov (United States)

    Heyman, Joseph S. (Inventor)

    1993-01-01

    A method and apparatus are provided for acoustophoresis, i.e., the separation of species via acoustic waves. An ultrasonic transducer applies an acoustic wave to one end of a sample container containing at least two species having different acoustic absorptions. The wave has a frequency tuned to or harmonized with the point of resonance of the species to be separated. This wave causes the species to be driven to an opposite end of the sample container for removal. A second ultrasonic transducer may be provided to apply a second, oppositely directed acoustic wave to prevent undesired streaming. In addition, a radio frequency tuned to the mechanical resonance and coupled with a magnetic field can serve to identify a species in a medium comprising species with similar absorption coefficients, whereby an acoustic wave having a frequency corresponding to this gyrational rate can then be applied to sweep the identified species to one end of the container for removal.

  17. Remanufacturability and Assessment Method

    Institute of Scientific and Technical Information of China (English)

    ZHUSheng; CUIPei-zhi; YAOJu-kun

    2004-01-01

    Remanufacturing represents the combination of "three Rs" (reduce, reuse, recycle) into a single activity, which restores a wide variety of worn-out, discarded durable products to like-new condition, prolonging their useful life, protecting the environment. The application of surface engineering has promoted the development of remanufacturing. Remanufacturing is an environmentally and economically sound way to achieve many of the goals of sustainable development. Through developing study of product design for remanufacturing, it can promote the surface technologies application in the remanufacturing, and markedly enhance the efficiency of remanufacturing. This paper gives some relative concepts about product design for remanufacturing, such as remanufacturability, and brings forward the remanufacturability research contents and assessment method of used product.

  18. Gas centrifuge purge method

    Science.gov (United States)

    Theurich, Gordon R.

    1976-01-01

    1. In a method of separating isotopes in a high speed gas centrifuge wherein a vertically oriented cylindrical rotor bowl is adapted to rotate about its axis within an evacuated chamber, and wherein an annular molecular pump having an intake end and a discharge end encircles the uppermost portion of said rotor bowl, said molecular pump being attached along its periphery in a leak-tight manner to said evacuated chamber, and wherein end cap closure means are affixed to the upper end of said rotor bowl, and a process gas withdrawal and insertion system enters said bowl through said end cap closure means, said evacuated chamber, molecular pump and end cap defining an upper zone at the discharge end of said molecular pump, said evacuated chamber, molecular pump and rotor bowl defining a lower annular zone at the intake end of said molecular pump, a method for removing gases from said upper and lower zones during centrifuge operation with a minimum loss of process gas from said rotor bowl, comprising, in combination: continuously measuring the pressure in said upper zone, pumping gas from said lower zone from the time the pressure in said upper zone equals a first preselected value until the pressure in said upper zone is equal to a second preselected value, said first preselected value being greater than said second preselected value, and continuously pumping gas from said upper zone from the time the pressure in said upper zone equals a third preselected value until the pressure in said upper zone is equal to a fourth preselected value, said third preselected value being greater than said first, second and fourth preselected values.

  19. Characterization Methods of Encapsulates

    Science.gov (United States)

    Zhang, Zhibing; Law, Daniel; Lian, Guoping

    , reliable methods which can be used to characterize these properties of encapsulates are vital. In this chapter, the state-of-art of these methods, their principles and applications, and release mechanisms are described as follows.

  20. Location predicting methods for UAVs

    Science.gov (United States)

    Peng, Xiaodong; Zhang, Yu

    2017-08-01

    Location prediction of unmanned aerial vehicle (UAV) is important for fighting with its enemy and ensuring its normal operation. This paper presents the motion model of UAVs and reduces the state space into 7 dimensions. The Bayesian Network, Markov Chain, Curve Fitting and Neural Network are introduced for designing predicting methods. Then Curve Fitting Predicting method, Markov Chain Predicting method, Bayesian Network Predicting method and Neural Network Predicting method are designed for UAVs. The simulation result shows that 1) Neural Network Predicting method has highest predicting accuracy; 2) Markov Chain Predicting method and Bayesian Network Predicting method methods have similar performance and both are better than Bayesian Network Predicting method methods; 3) Neural Network Predicting method is the first choice when predicting the locations of UAVs.