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Sample records for airway cross-sectional area

  1. Epiglottis cross-sectional area and oropharyngeal airway length in male and female obstructive sleep apnea patients

    PubMed Central

    Ma, Melinda A; Kumar, Rajesh; Macey, Paul M; Yan-Go, Frisca L; Harper, Ronald M

    2016-01-01

    Introduction Obstructive sleep apnea (OSA) is a male-predominant condition, characterized by repeated upper-airway collapse with continued diaphragmatic efforts during sleep, and is accompanied by severe physiological consequences. Multiple morphological aspects, including epiglottis cross-sectional area (CSA) and oropharyngeal airway length (OPAL), can contribute to airway collapsibility in the condition. This study focused on the effects of OSA severity, sex, and race on OPA dimensions. Materials and methods Two high-resolution T1-weighted image series were collected from 40 mild-to-severe OSA subjects (age 46.9±9 years, body mass index 30.4±5.4 kg/m2, Apnea–Hypopnea Index score 32.8±22.5, 28 males) and 54 control subjects (47±9 years, 24.7±3.8 kg/m2, 32 males) using a 3 T magnetic resonance-imaging scanner. Caucasian, Asian, African-American, and “other” subjects constituted the study pool. Both image series were realigned and averaged, and reoriented to a common space. CSA and OPAL were measured, normalized for subject height, and compared between sexes and disease-severity levels in OSA and control subjects. Results Significantly reduced epiglottis CSA appeared only in severe OSA vs controls (P=0.009). OPAL increased significantly with OSA severity vs controls (mild, P=0.027; moderate, P<0.001; severe, P<0.001). OSA males showed increased CSA and greater OPAL than OSA females, which may underlie the increased proportion of affected males with higher apnea–hypopnea index scores. However, no significant differences appeared between CSA and OPAL measures for male and female controls, suggesting that airway morphology may not be the sole contributor for airway collapse. No ethnic or racial differences appeared for CSA or OPAL measures. Conclusion Sex-based reductions in epiglottis CSA and increased OPAL in OSA subjects may enhance airway-collapse vulnerability, more so with greater disease severity, and partially underlie male vs female susceptibility

  2. Evaluation of Cross-section Airway Configuration of Obstructive Sleep Apnea

    PubMed Central

    Ogawa, Takumi; Enciso, Reyes; Shintaku, Werner H.; Clark, Glenn T.

    2007-01-01

    Upper airway imaging techniques can be useful to identify the exact location and nature of the obstruction in obstructive sleep apnea (OSA) patients. Methods Ten OSA patients and ten non-OSA control subjects were imaged using cone-beam computed tomography (Newtom QR-DVT9000) to compare their upper airway structure. Results The OSA subjects presented higher BMI (OSA: 29.5 ± 9.05 kg/m2; Non-OSA: 23.1 ± 3.05 kg/m2 [p=0.034]), lower total volume (mm3) of the airway (OSA: 4868.4 ± 1863.9; Non-OSA: 6051.7 ± 1756.4 [p =0.054]), statistically significantly smaller anterior-posterior dimension (mm) of the minimum cross-section segment (OSA: 4.6 ± 1.2; Non-OSA: 7.8 ± 3.31 [p =0.009]), and smaller minimum cross-section area (OSA: 45.8±17.5 mm2; Non-OSA: 146.9±111.7 mm2 [p=0.011]) positioned below the occlusal plane in 70% of the cases (OSA:7 out of 10; Non-OSA: 5 out of 10 [p=0.030]). The OSA group presented a concave or elliptic shaped airway and the non-OSA group presented a concave, round or square shaped airway. (156 words) PMID:17178502

  3. Peripheral nerve imaging: Not only cross-sectional area.

    PubMed

    Tagliafico, Alberto Stefano

    2016-08-28

    Peripheral nerve imaging is recognized as a complement to clinical and neurophysiological assessment in the evaluation of peripheral nerves with the ability to impact patient management, even for small and difficult nerves. The European Society of Musculoskeletal Radiology, suggest to use ultrasound (US) for nerve evaluation due to the fact that, in sever anatomical area, magnetic resonance imaging is not able to give additional informations. US could be considered the first-choice approach for the assessment of peripheral nerves. The relative drawback of peripheral nerve US is the long learning curve and the deep anatomic competence to evaluate even small nerves. In the recent years, the role of US in peripheral nerve evaluation has been widened. In the past, nerve US was mainly used to assess nerve-cross sectional area, but now more advanced measurements and considerations are desirable and can boost the role of peripheral nerve US. Nerve echotexture evaluation was defined in 2010: The ratio between the hypoechoic and hyperechoic areas of peripheral nerves on US was called "nerve density". For evaluation of patients who have peripheral neuropathies, the role of peripheral nerve is US wider than simple cross-sectional area evaluation. Quantitative measurements describing the internal fascicular echotexture of peripheral nerves introduce the concept of considering US as a possible quantitative imaging biomarker technique. The potential of nerve US has started to be uncovered. It seems clear that only cross-sectional area measurement is no more sufficient for a comprehensive US evaluation of peripheral nerves.

  4. Peripheral nerve imaging: Not only cross-sectional area

    PubMed Central

    Tagliafico, Alberto Stefano

    2016-01-01

    Peripheral nerve imaging is recognized as a complement to clinical and neurophysiological assessment in the evaluation of peripheral nerves with the ability to impact patient management, even for small and difficult nerves. The European Society of Musculoskeletal Radiology, suggest to use ultrasound (US) for nerve evaluation due to the fact that, in sever anatomical area, magnetic resonance imaging is not able to give additional informations. US could be considered the first-choice approach for the assessment of peripheral nerves. The relative drawback of peripheral nerve US is the long learning curve and the deep anatomic competence to evaluate even small nerves. In the recent years, the role of US in peripheral nerve evaluation has been widened. In the past, nerve US was mainly used to assess nerve-cross sectional area, but now more advanced measurements and considerations are desirable and can boost the role of peripheral nerve US. Nerve echotexture evaluation was defined in 2010: The ratio between the hypoechoic and hyperechoic areas of peripheral nerves on US was called “nerve density”. For evaluation of patients who have peripheral neuropathies, the role of peripheral nerve is US wider than simple cross-sectional area evaluation. Quantitative measurements describing the internal fascicular echotexture of peripheral nerves introduce the concept of considering US as a possible quantitative imaging biomarker technique. The potential of nerve US has started to be uncovered. It seems clear that only cross-sectional area measurement is no more sufficient for a comprehensive US evaluation of peripheral nerves.

  5. Peripheral nerve imaging: Not only cross-sectional area.

    PubMed

    Tagliafico, Alberto Stefano

    2016-08-28

    Peripheral nerve imaging is recognized as a complement to clinical and neurophysiological assessment in the evaluation of peripheral nerves with the ability to impact patient management, even for small and difficult nerves. The European Society of Musculoskeletal Radiology, suggest to use ultrasound (US) for nerve evaluation due to the fact that, in sever anatomical area, magnetic resonance imaging is not able to give additional informations. US could be considered the first-choice approach for the assessment of peripheral nerves. The relative drawback of peripheral nerve US is the long learning curve and the deep anatomic competence to evaluate even small nerves. In the recent years, the role of US in peripheral nerve evaluation has been widened. In the past, nerve US was mainly used to assess nerve-cross sectional area, but now more advanced measurements and considerations are desirable and can boost the role of peripheral nerve US. Nerve echotexture evaluation was defined in 2010: The ratio between the hypoechoic and hyperechoic areas of peripheral nerves on US was called "nerve density". For evaluation of patients who have peripheral neuropathies, the role of peripheral nerve is US wider than simple cross-sectional area evaluation. Quantitative measurements describing the internal fascicular echotexture of peripheral nerves introduce the concept of considering US as a possible quantitative imaging biomarker technique. The potential of nerve US has started to be uncovered. It seems clear that only cross-sectional area measurement is no more sufficient for a comprehensive US evaluation of peripheral nerves. PMID:27648165

  6. Peripheral nerve imaging: Not only cross-sectional area

    PubMed Central

    Tagliafico, Alberto Stefano

    2016-01-01

    Peripheral nerve imaging is recognized as a complement to clinical and neurophysiological assessment in the evaluation of peripheral nerves with the ability to impact patient management, even for small and difficult nerves. The European Society of Musculoskeletal Radiology, suggest to use ultrasound (US) for nerve evaluation due to the fact that, in sever anatomical area, magnetic resonance imaging is not able to give additional informations. US could be considered the first-choice approach for the assessment of peripheral nerves. The relative drawback of peripheral nerve US is the long learning curve and the deep anatomic competence to evaluate even small nerves. In the recent years, the role of US in peripheral nerve evaluation has been widened. In the past, nerve US was mainly used to assess nerve-cross sectional area, but now more advanced measurements and considerations are desirable and can boost the role of peripheral nerve US. Nerve echotexture evaluation was defined in 2010: The ratio between the hypoechoic and hyperechoic areas of peripheral nerves on US was called “nerve density”. For evaluation of patients who have peripheral neuropathies, the role of peripheral nerve is US wider than simple cross-sectional area evaluation. Quantitative measurements describing the internal fascicular echotexture of peripheral nerves introduce the concept of considering US as a possible quantitative imaging biomarker technique. The potential of nerve US has started to be uncovered. It seems clear that only cross-sectional area measurement is no more sufficient for a comprehensive US evaluation of peripheral nerves. PMID:27648165

  7. Analytical technique for satellite projected cross-sectional area calculation

    NASA Astrophysics Data System (ADS)

    Ben-Yaacov, Ohad; Edlerman, Eviatar; Gurfil, Pini

    2015-07-01

    Calculating the projected cross-sectional area (PCSA) of a satellite along a given direction is essential for implementing attitude control modes such as Sun pointing or minimum-drag. The PCSA may also be required for estimating the forces and torques induced by atmospheric drag and solar radiation pressure. This paper develops a new analytical method for calculating the PCSA, the concomitant torques and the satellite exposed surface area, based on the theory of convex polygons. A scheme for approximating the outer surface of any satellite by polygons is developed. Then, a methodology for calculating the projections of the polygons along a given vector is employed. The methodology also accounts for overlaps among projections, and is capable of providing the true PCSA in a computationally-efficient manner. Using the Space Autonomous Mission for Swarming and Geo-locating Nanosatellites mechanical model, it is shown that the new analytical method yields accurate results, which are similar to results obtained from alternative numerical tools.

  8. Influence of knee alignment on quadriceps cross-sectional area.

    PubMed

    Sogabe, Akitoshi; Mukai, Naoki; Miyakawa, Shunpei; Mesaki, Noboru; Maeda, Kazuaki; Yamamoto, Tadashi; Gallagher, Philip M; Schrager, Matt; Fry, Andrew C

    2009-10-16

    Previous studies of methods for stimulating the individual muscles composing the quadriceps femoris have not considered the structural features of a subject's knee joint. In this study, we compared the ratios of the individual muscles composing the quadriceps between subjects with different knee alignments using magnetic resonance (MR) imaging. A total of 18 healthy males were examined: 6 normal knees (age, 23.0+/-0.6 yr; femorotibial angle (FTA), 176.8+/-0.4 degrees), 6 genu varum (age, 21.8+/-2.9 yr; FTA, 181.7+/-2.6 degrees) and 6 genu valgum (age, 21.0+/-1.6 yr; FTA, 172.3+/-1.5 degrees). The cross-sectional areas (CSAs) of quadriceps muscles were obtained by MR imaging of the entire left thigh. The CSAs of the vastus lateralis (VL), rectus femoris (RF), vastus medialis (VM) and vastus intermedius (VI) muscles were obtained by MR imaging of the entire left thigh in a supine position. The VM/VL ratio was also obtained by dividing the CSA of the VM by that of the VL and compared among the three groups of subjects with different knee alignments. The genu varum group showed a significantly higher %CSA of VM in the CSA of the quadriceps (VM/Quad) (49.0+/-2.6%) than values for the other two groups. The genu valgum group showed significantly higher values of RF/Quad (15.2+/-2.1%) and VL/Quad (40.6+/-4.0%) than the other groups. The VM/VL ratio was significantly higher in the genu varum than in values for the other two groups. This difference in CSA, in respect to knee alignment, may be considered when devising muscle training programs. PMID:19698946

  9. Pore cross-section area on predicting elastic properties of trabecular bovine bone for human implants.

    PubMed

    Maciel, Alfredo; Presbítero, Gerardo; Piña, Cristina; del Pilar Gutiérrez, María; Guzmán, José; Munguía, Nadia

    2015-01-01

    A clear understanding of the dependence of mechanical properties of bone remains a task not fully achieved. In order to estimate the mechanical properties in bones for implants, pore cross-section area, calcium content, and apparent density were measured in trabecular bone samples for human implants. Samples of fresh and defatted bone tissue, extracted from one year old bovines, were cut in longitudinal and transversal orientation of the trabeculae. Pore cross-section area was measured with an image analyzer. Compression tests were conducted into rectangular prisms. Elastic modulus presents a linear tendency as a function of pore cross-section area, calcium content and apparent density regardless of the trabecular orientation. The best variable to estimate elastic modulus of trabecular bone for implants was pore cross-section area, and affirmations to consider Nukbone process appropriated for marrow extraction in trabecular bone for implantation purposes are proposed, according to bone mechanical properties. Considering stress-strain curves, defatted bone is stiffer than fresh bone. Number of pores against pore cross-section area present an exponential decay, consistent for all the samples. These graphs also are useful to predict elastic properties of trabecular samples of young bovines for implants.

  10. Average Cross-Sectional Area of DebriSat Fragments Using Volumetrically Constructed 3D Representations

    NASA Technical Reports Server (NTRS)

    Scruggs, T.; Moraguez, M.; Patankar, K.; Fitz-Coy, N.; Liou, J.-C.; Sorge, M.; Huynh, T.

    2016-01-01

    Debris fragments from the hypervelocity impact testing of DebriSat are being collected and characterized for use in updating existing satellite breakup models. One of the key parameters utilized in these models is the ballistic coefficient of the fragment which is directly related to its area-to-mass ratio. However, since the attitude of fragments varies during their orbital lifetime, it is customary to use the average cross-sectional area in the calculation of the area-to-mass ratio. The average cross-sectional area is defined as the average of the projected surface areas perpendicular to the direction of motion and has been shown to be equal to one-fourth of the total surface area of a convex object. Unfortunately, numerous fragments obtained from the DebriSat experiment show significant concavity (i.e., shadowing) and thus we have explored alternate methods for computing the average cross-sectional area of the fragments. An imaging system based on the volumetric reconstruction of a 3D object from multiple 2D photographs of the object was developed for use in determining the size characteristic (i.e., characteristics length) of the DebriSat fragments. For each fragment, the imaging system generates N number of images from varied azimuth and elevation angles and processes them using a space-carving algorithm to construct a 3D point cloud of the fragment. This paper describes two approaches for calculating the average cross-sectional area of debris fragments based on the 3D imager. Approach A utilizes the constructed 3D object to generate equally distributed cross-sectional area projections and then averages them to determine the average cross-sectional area. Approach B utilizes a weighted average of the area of the 2D photographs to directly compute the average cross-sectional area. A comparison of the accuracy and computational needs of each approach is described as well as preliminary results of an analysis to determine the "optimal" number of images needed for

  11. Signal intensity, clinical activity and cross-sectional areas on MRI scans in thyroid eye disease.

    PubMed

    Mayer, E J; Fox, D L; Herdman, G; Hsuan, J; Kabala, J; Goddard, P; Potts, M J; Lee, R W J

    2005-10-01

    The signal intensity from inflamed extra-ocular muscles on short tau inversion recovery (STIR)-sequence magnetic resonance imaging (MRI) is known to correlate with clinical scores of thyroid eye disease (TED) severity. Twenty-one patients who had undergone repeated MRI scanning for TED were studied retrospectively. Signal intensity of extra-ocular muscles (from STIR-sequence MRI) and cross-sectional area (from STIR and T1 MRI) were correlated with Mourits' clinical activity score (CAS). The area of highest signal intensity within the most inflamed extra-ocular muscle, and the average cross-sectional signal intensity of the most inflamed extra-ocular muscle reliably correlated with CAS, and this was maintained as disease activity changed over time. In contrast, isolated measures of muscle cross-sectional area did not correlate with CAS. The extra-ocular muscle cross-sectional area calculated from STIR-sequence MR images was greater than that measured on T1 images. This suggests that muscle area from STIR-sequence MRI may also detect peri-muscular inflammation. We conclude that the peak signal intensity from the most inflamed extra-ocular muscle remains the most reliable correlate of clinical disease activity obtained from these images. STIR-sequence MRI scans provide a number of useful measures of disease activity in TED.

  12. Automated image analysis of skeletal muscle fiber cross-sectional area

    PubMed Central

    Mula, Jyothi; Lee, Jonah D.; Liu, Fujun; Yang, Lin

    2013-01-01

    Morphological characteristics of muscle fibers, such as fiber size, are critical factors that determine the health and function of the muscle. However, at this time, quantification of muscle fiber cross-sectional area is still a manual or, at best, a semiautomated process. This process is labor intensive, time consuming, and prone to errors, leading to high interobserver variability. We have developed and validated an automatic image segmentation algorithm and compared it directly with commercially available semiautomatic software currently considered state of the art. The proposed automatic segmentation algorithm was evaluated against a semiautomatic method with manual annotation using 35 randomly selected cross-sectional muscle histochemical images. The proposed algorithm begins with ridge detection to enhance the muscle fiber boundaries, followed by robust seed detection based on concave area identification to find initial seeds for muscle fibers. The final muscle fiber boundaries are automatically delineated using a gradient vector flow deformable model. Our automatic approach is accurate and represents a significant advancement in efficiency; quantification of fiber area in muscle cross sections was reduced from 25–40 min/image to 15 s/image, while accommodating common quantification obstacles including morphological variation (e.g., heterogeneity in fiber size and fibrosis) and technical artifacts (e.g., processing defects and poor staining quality). Automatic quantification of muscle fiber cross-sectional area using the proposed method is a powerful tool that will increase sensitivity, objectivity, and efficiency in measuring muscle adaptation. PMID:23139362

  13. Algorithm for Calculating the Cross-Section Areas of the Vocal Tract

    NASA Astrophysics Data System (ADS)

    Badin, P.; Makarov, I. S.; Sorokin, V. N.

    2005-02-01

    It is found that the articulation process is accompanied by active variations of the pharynx width. To describe the latter, a linear combination of two width eigenvectors with varying coefficients is proposed. A new algorithm is constructed for calculating the cross-section areas of the vocal tract. The algorithm takes into account not only the anatomic parameters and the shape of the tract in the saggital plane but also the parameters in the lateral and axial planes.

  14. The Predictability from Skull Morphology of Temporalis and Masseter Muscle Cross-Sectional Areas in Humans.

    PubMed

    Toro-Ibacache, Viviana; Zapata MuÑoz, Victor; O'higgins, Paul

    2015-07-01

    To carry out functional simulations of the masticatory system that aim to predict strain magnitudes it is important to apply appropriate jaw-elevator muscle forces. Force magnitude estimation from directly measured muscle physiological cross-sectional area or anatomical cross-sectional area (CSA) is not possible for fossils and skeletal material from museum collections. In these cases, muscle CSAs are often estimated from bony features. This approach has been shown to be inaccurate in a prior study based on direct measurements from cadavers. Postmortem alterations as well as age changes in muscle form might explain this discrepancy. As such, the present study uses CT images from 20 living individuals to directly measure temporalis and masseter muscle CSAs and estimated cross-sectional areas (ECSAs) from bony features. The relationships between CSAs and ECSAs were assessed by comparing mean values and by examining correlations. ECSAs are up to 100% greater than CSA and the means of these variables for each muscle differ significantly. Further, ECSA is significantly correlated with CSA for temporalis but not masseter. Cranial centroid size is only significantly associated with CSA for temporalis. These findings indicate that ECSAs should be employed with caution in simulations of human masticatory system functioning; they do not reflect CSAs and it is plausible that this also applies to studies of closely related living and fossil taxa. When ECSAs are used, sensitivity analyses are required to determine the impact of potential errors.

  15. For Better Calculation of the Average Cross-Sectional Area of Breakup Fragments

    NASA Astrophysics Data System (ADS)

    Hanada, Toshiya; Liou, Jer-Chyi; Krisko, Paula; Nakajima, Takashi

    This paper proposes a new approach to improve the calculation of the average cross-sectional area of breakup fragments, and a new technique for modeling the area-to-mass ratio distribution resulting from the new approach. This paper applies the proposed methods to the re-analysis of fragments from micro-satellite impact tests completed in late 2005. It can be concluded that the area-to-mass ratio distribution model resulting from the proposed methods fits very well with the fragments observed in the micro-satellite impact tests.

  16. MRI shows increased sciatic nerve cross sectional area in inherited and inflammatory neuropathies.

    PubMed

    Sinclair, C D J; Miranda, M A; Cowley, P; Morrow, J M; Davagnanam, I; Mehta, H; Hanna, M G; Koltzenburg, M; Reilly, M M; Yousry, T A; Thornton, J S

    2011-11-01

    Measurements of the cross sectional area of the sciatic nerve are described in a group of 10 patients with genetically confirmed Charcot-Marie-Tooth disease type 1A (CMT1A), nine patients with chronic inflammatory demyelinating polyneuropathy (CIDP) and 10 healthy controls using MRI. One mid-thigh of each individual was imaged using a short tau inversion recovery sequence and the nerve appearance evaluated radiologically with respect to the signal intensity and visibility of the internal neural structure. The cross sectional area of the sciatic nerve of each individual was measured by defining irregular enclosing regions of interest on the MRI images. The sciatic nerve area was enlarged in both CMT1A (p<0.001) and CIDP (p=0.008) compared with controls and in CMT1A compared with CIDP (p<0.001). Median (interquartile range) areas were 67.6 (16.2) mm(2) for the CIDP group, 135.9 (46.5) mm(2) for the CMT1A group and 43.3 (19.9) mm(2) for the control group. The critical upper value for discriminating pathologically enlarged nerves from normal controls with p<0.05 was 64.4 mm(2). Quantification of sciatic nerve hypertrophy on MRI may be of assistance in cases where the diagnosis is still in doubt, providing an objective pathological marker complimenting other clinical investigations.

  17. An evaluation of the reliability of muscle fiber cross-sectional area and fiber number measurements in rat skeletal muscle

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background: The reliability of estimating muscle fiber cross-sectional area (measure of muscle fiber size) and fiber number from only a subset of fibers in rat hindlimb muscle cross-sections has not been systematically evaluated. This study examined the variability in mean estimates of fiber cross-s...

  18. Fort Bliss Geothermal Area Data: Temperature profile, logs, schematic model and cross section

    SciTech Connect

    Adam Brandt

    2015-11-15

    This dataset contains a variety of data about the Fort Bliss geothermal area, part of the southern portion of the Tularosa Basin, New Mexico. The dataset contains schematic models for the McGregor Geothermal System, a shallow temperature survey of the Fort Bliss geothermal area. The dataset also contains Century OH logs, a full temperature profile, and complete logs from well RMI 56-5, including resistivity and porosity data, drill logs with drill rate, depth, lithology, mineralogy, fractures, temperature, pit total, gases, and descriptions among other measurements as well as CDL, CNL, DIL, GR Caliper and Temperature files. A shallow (2 meter depth) temperature survey of the Fort Bliss geothermal area with 63 data points is also included. Two cross sections through the Fort Bliss area, also included, show well position and depth. The surface map included shows faults and well spatial distribution. Inferred and observed fault distributions from gravity surveys around the Fort Bliss geothermal area.

  19. Odor tracking flight of male Manduca sexta moths along plumes of different cross-sectional area.

    PubMed

    Willis, Mark A; Ford, E A; Avondet, J L

    2013-11-01

    Males of the hawkmoth, Manduca sexta, track wind-borne plumes of female sex pheromone by flying upwind, while continuously turning from side-to-side and changing altitude. Their characteristic "zigzagging" trajectory has long been thought to result from the interaction of two mechanisms, an odor-modulated orientation to wind and a built-in central nervous system turning program. An interesting and as of yet unanswered question about this tracking behavior is how the cross-section of an odor plume or its clean-air "edges" affects moths' odor tracking behavior. This study attempts to address this question by video recording and analyzing the behavior of freely flying M. sexta males tracking plumes from pheromone sources of different lengths and orientations with equal odor concentration per unit area. Our results showed that moths generated significantly wider tracks in wide plumes from the longest horizontally-oriented sources as compared to narrower point-source plumes, but had relatively unaltered tracks when orienting to plumes from the same length sources oriented vertically. This suggests that in addition to wind and the presence of pheromones, the area of the plume's cross section or its edges may also play an important role in the plume tracking mechanisms of M. sexta.

  20. Robust estimation of physiological cross-sectional area and geometric reconstruction for human skeletal muscle.

    PubMed

    Lee, Dongwoon; Ravichandiran, Kajeandra; Jackson, Ken; Fiume, Eugene; Agur, Anne

    2012-05-11

    Understanding muscle architecture is crucial to determining the mechanical function of muscle during body movements, because architectural parameters directly correspond to muscle performance. Accurate parameters are thus essential for reliable simulation. Human cadaveric muscle specimen data provides the anatomical detail needed for in-depth understanding of muscle and accurate parameter estimation. However, as muscle generally has non-uniform architecture, parameter estimation, specifically, physiological cross-sectional area (PCSA), is rarely straightforward. To deal effectively with this non-uniformity, we propose a geometric approach in which a polygon is sought to best approximate the cross-sectional area of each fascicle by accounting for its three-dimensional trajectory and arrangement in the muscle. Those polygons are then aggregated to determine PCSA and volume of muscle. Experiments are run using both synthetic data and muscle specimen data. From comparison of PCSA using synthetic data, we conclude that the proposed method enhances the robustness of PCSA estimation against variation in muscle architecture. Furthermore, we suggest reconstruction methods to extract 3D muscle geometry directly from fascicle data and estimated parameters using the level set method. PMID:22406468

  1. Odor tracking flight of male Manduca sexta moths along plumes of different cross-sectional area.

    PubMed

    Willis, Mark A; Ford, E A; Avondet, J L

    2013-11-01

    Males of the hawkmoth, Manduca sexta, track wind-borne plumes of female sex pheromone by flying upwind, while continuously turning from side-to-side and changing altitude. Their characteristic "zigzagging" trajectory has long been thought to result from the interaction of two mechanisms, an odor-modulated orientation to wind and a built-in central nervous system turning program. An interesting and as of yet unanswered question about this tracking behavior is how the cross-section of an odor plume or its clean-air "edges" affects moths' odor tracking behavior. This study attempts to address this question by video recording and analyzing the behavior of freely flying M. sexta males tracking plumes from pheromone sources of different lengths and orientations with equal odor concentration per unit area. Our results showed that moths generated significantly wider tracks in wide plumes from the longest horizontally-oriented sources as compared to narrower point-source plumes, but had relatively unaltered tracks when orienting to plumes from the same length sources oriented vertically. This suggests that in addition to wind and the presence of pheromones, the area of the plume's cross section or its edges may also play an important role in the plume tracking mechanisms of M. sexta. PMID:24081678

  2. Bias and precision of algorithms in estimating the cross-sectional area of rat tail tendons

    NASA Astrophysics Data System (ADS)

    Parent, Gabriel; Cyr, Matthieu; Desbiens-Blais, Frédérique; Langelier, Ève

    2010-12-01

    The cross-section area (CSA) of rat tail tendons (RTTs), a common experimental model in biomechanics and mechanobiology, is often approximated using circle or ellipse models. This assumption may nevertheless be faulty given the sensitivity of the mechanical properties on CSA estimation. To investigate this issue, we designed a new optic micrometer to be used under a stereomicroscope. Images of specimen projections were captured at angular increments and specimen edges were localized within a local reference frame using an image analysis algorithm based on contrast. The cross-sectional areas estimated using four algorithms (single measurement circle, multiple measurement circle, two degrees of freedom ellipse, three degrees of freedom ellipse) were compared to those obtained using the best algorithm currently described in the literature: the profile reconstruction algorithm. We showed that the four tested algorithms exhibit moderate but uniform bias (mean systematic error between 7 and 11%) with very non-uniform precision, varying from excellent to very poor (adjusted root mean square deviation between 0 and 19%). The maximum CSA error was found to be as high as 99%. We therefore recommend avoiding the algorithms approximating the RTT CSA using circle or ellipse models in studies where accurate estimation of the CSA is required.

  3. Changes in intervertebral disc cross-sectional area with bed rest and space flight

    NASA Technical Reports Server (NTRS)

    LeBlanc, A. D.; Evans, H. J.; Schneider, V. S.; Wendt, R. E. 3rd; Hedrick, T. D.

    1994-01-01

    STUDY DESIGN. We measured the cross-sectional area of the intervertebral discs of normal volunteers after an overnight rest; before, during, and after 5 or 17 weeks of bed rest; and before and after 8 days of weightlessness. OBJECTIVES. This study sought to determine the degree of expansion of the lumbar discs resulting from bed rest and space flight. SUMMARY OF BACKGROUND DATA. Weightlessness and bed rest, an analog for weightlessness, reduce the mechanical loading on the musculoskeletal system. When unloaded, intervertebral discs will expand, increasing the nutritional diffusion distance and altering the mechanical properties of the spine. METHODS. Magnetic resonance imaging was used to measure the cross-sectional area and transverse relaxation time (T2) of the intervertebral discs. RESULTS. Overnight or longer bed rest causes expansion of the disc area, which reaches an equilibrium value of about 22% (range 10-40%) above baseline within 4 days. Increases in disc area were associated with modest increases in disc T2. During bed rest, disc height increased approximately 1 mm, about one-half of previous estimates based on body height measurements. After 5 weeks of bed rest, disc area returned to baseline within a few days of ambulation, whereas after 17 weeks, disc area remained above baseline 6 weeks after reambulation. After 8 days of weightlessness, T2, disc area, and lumbar length were not significantly different from baseline values 24 hours after landing. CONCLUSIONS. Significant adaptive changes in the intervertebral discs can be expected during weightlessness. These changes, which are rapidly reversible after short-duration flights, may be an important factor during and after long-duration missions.

  4. Best estimate of luminal cross-sectional area of coronary arteries from angiograms

    NASA Technical Reports Server (NTRS)

    Lee, P. L.; Selzer, R. H.

    1988-01-01

    We have reexamined the problem of estimating the luminal area of an elliptically-shaped coronary artery cross section from two or more radiographic diameter measurements. The expected error is found to be much smaller than the maximum potential error. In the cae of two orthogonal views, closed form expressions have been derived for calculating the area and the uncertainty. Assuming that the underlying ellipse has limited ellipticity (major/minor axis ratio less than five), it is shown that the average uncertainty in the area is less than 14 percent. When more than two views are available, we suggest using a least-squares fit method to extract all available information from the data.

  5. Automated fiber-type-specific cross-sectional area assessment and myonuclei counting in skeletal muscle

    PubMed Central

    Liu, Fujun; Fry, Christopher S.; Mula, Jyothi; Jackson, Janna R.; Lee, Jonah D.; Peterson, Charlotte A.

    2013-01-01

    Skeletal muscle is an exceptionally adaptive tissue that compromises 40% of mammalian body mass. Skeletal muscle functions in locomotion, but also plays important roles in thermogenesis and metabolic homeostasis. Thus characterizing the structural and functional properties of skeletal muscle is important in many facets of biomedical research, ranging from myopathies to rehabilitation sciences to exercise interventions aimed at improving quality of life in the face of chronic disease and aging. In this paper, we focus on automated quantification of three important morphological features of muscle: 1) muscle fiber-type composition; 2) muscle fiber-type-specific cross-sectional area, and 3) myonuclear content and location. We experimentally prove that the proposed automated image analysis approaches for fiber-type-specific assessments and automated myonuclei counting are fast, accurate, and reliable. PMID:24092696

  6. The tunneling magnetoresistance current dependence on cross sectional area, angle and temperature

    SciTech Connect

    Zhang, Z. H. Bai, Lihui; Hu, C.-M.; Hemour, S.; Wu, K.; Fan, X. L.; Xue, D. S.; Houssameddine, D.

    2015-03-15

    The magnetoresistance of a MgO-based magnetic tunnel junction (MTJ) was studied experimentally. The magnetoresistance as a function of current was measured systematically on MTJs for various MgO cross sectional areas and at various temperatures from 7.5 to 290.1 K. The resistance current dependence of the MTJ was also measured for different angles between the two ferromagnetic layers. By considering particle and angular momentum conservation of transport electrons, the current dependence of magnetoresistance can be explained by the changing of spin polarization in the free magnetic layer of the MTJ. The changing of spin polarization is related to the magnetoresistance, its angular dependence and the threshold current where TMR ratio equals zero. A phenomenological model is used which avoid the complicated barrier details and also describes the data.

  7. An evolutionary attractor model for sapwood cross section in relation to leaf area.

    PubMed

    Westoby, Mark; Cornwell, William K; Falster, Daniel S

    2012-06-21

    Sapwood cross-sectional area per unit leaf area (SA:LA) is an influential trait that plants coordinate with physical environment and with other traits. We develop theory for SA:LA and also for root surface area per leaf area (RA:LA) on the premise that plants maximizing the surplus of revenue over costs should have competitive advantage. SA:LA is predicted to increase in water-relations environments that reduce photosynthetic revenue, including low soil water potential, high water vapor pressure deficit (VPD), and low atmospheric CO(2). Because sapwood has costs, SA:LA adjustment does not completely offset difficult water relations. Where sapwood costs are large, as in tall plants, optimal SA:LA may actually decline with (say) high VPD. Large soil-to-root resistance caps the benefits that can be obtained from increasing SA:LA. Where a plant can adjust water-absorbing surface area of root per leaf area (RA:LA) as well as SA:LA, optimal RA:SA is not affected by VPD, CO(2) or plant height. If selection favours increased height more so than increased revenue-minus-cost, then height is predicted to rise substantially under improved water-relations environments such as high-CO(2) atmospheres. Evolutionary-attractor theory for SA:LA and RA:LA complements models that take whole-plant conductivity per leaf area as a parameter.

  8. Flow structure caused by a local cross-sectional area increase and curvature in sharp river bends

    NASA Astrophysics Data System (ADS)

    Vermeulen, B.

    2015-12-01

    Horizontal flow recirculation is often observed in sharp river bends, causing a complex three-dimensional flow structure with large implications for the morphological and planimetric development of meanders. Several field observations in small scale systems show that sharp bends are often found in association with a strong increase in cross-sectional area, the deposition of outer bank benches and reattachment bars near the inner bank. Recent studies show that these bends can also occur in large scale systems. In this study, we present field measurements of a sharp bend in the Mahakam River, East Kalimantan, Indonesia. The cross-sectional area increases by a factor of three compared with the reach averaged cross-sectional area. Along a river reach of about 150 km, cross-sectional area correlates strongly with curvature. The field measurements are analyzed together with the results from numerical simulation with a 3D finite element model, which yields a comprehensive view of the intricate flow structure. In turn, the model is used to validate a new equation that captures the water surface topography dependence on cross-sectional area variation and curvature. The results show the importance of the increase in cross-sectional area in the development of horizontal recirculation. Vertical acceleration of the flow into the scour causes the pressure to deviate from a hydrostatic pressure distribution. Strong downflow (up to 12 cm/s) advects longitudinal momentum towards the bed, causing the flow to concentrate in the lower part of the cross-section. This increases the velocity magnitude throughout the cross-section, which is expected to maintain the large scour depth found in several bends along the Mahakam River.

  9. Interpretive geologic cross sections for the Death Valley regional flow system and surrounding areas, Nevada and California

    SciTech Connect

    D.S. Sweetkind; R.P. Dickerson; R.J. Blakely; P.D. Denning

    2001-11-09

    This report presents a network of 28 geologic cross sections that portray subsurface geologic relations within the Death Valley regional ground-water system, a ground-water basin that encompasses a 3 degree x 3 degree area (approximately 70,000 square kilometers) in southern Nevada and eastern California. The cross sections transect that part of the southern Great Basin that includes Death Valley, the Nevada Test Site, and the potential high-level nuclear waste underground repository at Yucca Mountain. The specific geometric relationships portrayed on the cross sections are discussed in the context of four general sub-regions that have stratigraphic similarities and general consistency of structural style: (1) the Nevada Test Site vicinity; (2) the Spring Mountains, Pahrump Valley and Amargosa Desert region; (3) the Death Valley region; and (4) the area east of the Nevada Test Site. The subsurface geologic interpretations portrayed on the cross sections are based on an integration of existing geologic maps, measured stratigraphic sections, published cross sections, well data, and geophysical data and interpretations. The estimated top of pre-Cenozoic rocks in the cross sections is based on inversion of gravity data, but the deeper parts of the sections are based on geologic conceptual models and are more speculative.

  10. Interpretive geologic cross sections for the Death Valley regional flow system and surrounding areas, Nevada and California

    USGS Publications Warehouse

    Sweetkind, D.S.; Dickerson, R.P.; Blakely, R.J.; Denning, P.D.

    2001-01-01

    This report presents a network of 28 geologic cross sections that portray subsurface geologic relations within the Death Valley regional ground-water system, a ground-water basin that encompasses a 3? x 3? area (approximately 70,000 km2) in southern Nevada and eastern California. The cross sections transect that part of the southern Great Basin that includes Death Valley, the Nevada Test Site, and the potential high-level nuclear waste underground repository at Yucca Mountain. The specific geometric relationships portrayed on the cross sections are discussed in the context of four general sub-regions that have stratigraphic similarities and general consistency of structural style: (1) the Nevada Test Site vicinity; (2) the Spring Mountains, Pahrump Valley and Amargosa Desert region; (3) the Death Valley region; and (4) the area east of the Nevada Test Site. The subsurface geologic interpretations portrayed on the cross sections are based on an integration of existing geologic maps, measured stratigraphic sections, published cross sections, well data, and geophysical data and interpretations. The estimated top of pre-Cenozoic rocks in the cross sections is based on inversion of gravity data, but the deeper parts of the sections are based on geologic conceptual models and are more speculative. The region transected by the cross sections includes part of the southern Basin and Range Province, the northwest-trending Walker Lane belt, the Death Valley region, and the northern Mojave Desert. The region is structurally complex, where a locally thick Tertiary volcanic and sedimentary section unconformably overlies previously deformed Proterozoic through Paleozoic rocks. All of these rocks have been deformed by complex Neogene ex-tensional normal and strike-slip faults. These cross sections form a three-dimensional network that portrays the interpreted stratigraphic and structural relations in the region; the sections form part of the geologic framework that will be

  11. Ultrasound Assessment of the Rectus Femoris Cross-Sectional Area: Subject Position Implications.

    PubMed

    Hacker, Eileen Danaher; Peters, Tara; Garkova, Miglena

    2016-09-01

    Ultrasonic measurement of the rectus femoris (RF) is a novel, proxy measure for muscle strength. The impact of hip flexion/head of bed positioning on RF cross-sectional area (CSA) has not been fully explored. This study describes and compares differences in RF CSA across four degrees of hip flexion. This repeated-measures, comparative study enrolled healthy, pre-menopausal women (n = 20). RF CSA of the dominant leg was measured using the SonoSite M-Turbo ultrasound system with the head of bed at 0°, 20°, 30°, and 60°. One-way repeated measures indicated significant differences in RF CSA, F(3, 17) = 14.18, p < .001, with variation in hip flexion/head of bed elevation and significant RF CSA differences between: (a) 0° and 20°, (b) 0° and 30°, (c) 0° and 60°, and (d) 20° and 60°. Standardizing patient positioning when conducting ultrasonic measurement of RF CSA is vital for researchers who assess muscle mass.

  12. Ultrasound Assessment of the Rectus Femoris Cross-Sectional Area: Subject Position Implications.

    PubMed

    Hacker, Eileen Danaher; Peters, Tara; Garkova, Miglena

    2016-09-01

    Ultrasonic measurement of the rectus femoris (RF) is a novel, proxy measure for muscle strength. The impact of hip flexion/head of bed positioning on RF cross-sectional area (CSA) has not been fully explored. This study describes and compares differences in RF CSA across four degrees of hip flexion. This repeated-measures, comparative study enrolled healthy, pre-menopausal women (n = 20). RF CSA of the dominant leg was measured using the SonoSite M-Turbo ultrasound system with the head of bed at 0°, 20°, 30°, and 60°. One-way repeated measures indicated significant differences in RF CSA, F(3, 17) = 14.18, p < .001, with variation in hip flexion/head of bed elevation and significant RF CSA differences between: (a) 0° and 20°, (b) 0° and 30°, (c) 0° and 60°, and (d) 20° and 60°. Standardizing patient positioning when conducting ultrasonic measurement of RF CSA is vital for researchers who assess muscle mass. PMID:27090872

  13. Thermoeconomic design and analysis of constant cross-sectional area fins

    NASA Astrophysics Data System (ADS)

    Shuja, S. Z.; Zubair, S. M.; Khan, M. S.

    A closed-form model for the second-law-based thermoeconomic optimization of constant cross-sectional area fins, is discussed with an example problem. In this approach, different monetary values are attached to the irreversible losses caused by the finite temperature difference heat transfer (T0ΔT) and pressure drop (T0ΔP) in the fin application. In addition, a simplified closed-form solution is presented for the case when the capital cost of the fin is negligible and only operational costs are considered. To illustrate the usefulness of the present analytical approach, the simplified cost optimized results are compared with the numerical results obtained from Poulikakos and Bejan's analysis, who have assumed same monetary values for T0ΔT and T0ΔP. Furthermore, the influence of important fin thermal, physical, geometrical and cost parameters on the optimum Reynolds numbers ReDopt and ReLopt are presented in algebraic forms, and also graphical results are shown for the case of pin and plate fin, as examples.

  14. Carpal Tunnel Cross-Sectional Area Affected by Soft Tissues Abutting the Carpal Bones.

    PubMed

    Gabra, Joseph N; Li, Zong-Ming

    2013-02-01

    The carpal tunnel accommodates free movement of its contents, and the tunnel's cross-sectional area is a useful morphological parameter for the evaluation of the space available for the carpal tunnel contents and of potential nerve compression in the tunnel. The osseous boundary of the carpal bones as the dorsal border of the carpal tunnel is commonly used to determine the tunnel area, but this boundary contains soft tissues such as numerous intercarpal ligaments and the flexor carpi radialis tendon. The aims of this study were to quantify the thickness of the soft tissues abutting the carpal bones and to investigate how this soft tissue influences the calculation of the carpal tunnel area. Magnetic resonance images were analyzed for eight cadaveric specimens. A medical balloon with a physiological pressure was inserted into an evacuated tunnel to identify the carpal tunnel boundary. The balloon-based (i.e. true carpal tunnel) and osseous-based carpal tunnel boundaries were extracted and divided into regions corresponding to the hamate, capitate, trapezoid, trapezium, and transverse carpal ligament (TCL). From the two boundaries, the overall and regional soft tissue thicknesses and areas were calculated. The soft tissue thickness was significantly greater for the trapezoid (3.1±1.2mm) and trapezium (3.4±1.0mm) regions than for the hamate (0.7±0.3mm) and capitate (1.2±0.5mm) regions. The carpal tunnel area using the osseous boundary (243.0±40.4mm(2)) was significantly larger than the balloon-based area (183.9±29.7mm(2)) with a ratio of 1.32. In other words, the carpal tunnel area can be estimated as 76% (= 1/1.32) of the osseous-based area. The abundance of soft tissue in the trapezoid and trapezium regions can be attributed mainly to the capitate-trapezium ligament and the flexor carpi radialis tendon. Inclusion of such soft tissue leads to overestimations of the carpal tunnel area. Correct quantification of the carpal tunnel area aids in examining carpal

  15. A spray flame propagating in a nonadiabatic duct with varying cross-sectional area

    SciTech Connect

    Tsai, Chih-Hsin; Hou, Shuhn-Shyurng; Lin, Ta-Hui

    2006-01-01

    The influence of flame stretch, preferential diffusion, internal heat transfer, and external heat loss on the extinction of dilute spray flames propagating in a nonadiabatic duct with varying cross-sectional area is analyzed using activation energy asymptotics. A completely prevaporized mode and a partially prevaporized mode of flame propagation are identified. Internal heat transfer, resulting from droplets gasifying, varies with the liquid-fuel loading and the initial droplet size in the spray and also provides internal heat loss for rich sprays but heat gain for lean sprays. A spray flame propagating in a divergent (convergent) duct experiences positive (negative) stretch. The results show that the burning intensity of a lean (or rich) spray is enhanced (or reduced) with an increased liquid-fuel loading or smaller initial droplets. The positive stretch coupled with the effects of the Lewis number (Le) weakens a lean methanol-spray flame (Le>1), but intensifies a rich methanol-spray flame (Le<1). For a positively stretched flame with Le<1 or a negatively stretched flame with Le>1, without external heat loss, no extinction occurs by increasing the stretch. However, irrespective of heat loss, a flame with Le>1 experiencing positive stretch or a flame with Le<1 enduring negative stretch can be extinguished by increasing the stretch. Flame extinction characterized by a C-shaped curve is dominated by stretch or external heat loss. Note that for a methanol-rich spray flame (Le<1) experiencing positive stretch and enduring a partially prevaporized spray composed of a large enough liquid loading and sufficiently large droplets, an S-shaped extinction curve can be obtained. The S-shaped curve, which differs from the C-shaped one, indicates that flame extinction is governed by internal heat loss.

  16. The effect of scaling physiological cross-sectional area on musculoskeletal model predictions.

    PubMed

    Bolsterlee, Bart; Vardy, Alistair N; van der Helm, Frans C T; Veeger, H E J DirkJan

    2015-07-16

    Personalisation of model parameters is likely to improve biomechanical model predictions and could allow models to be used for subject- or patient-specific applications. This study evaluates the effect of personalising physiological cross-sectional areas (PCSA) in a large-scale musculoskeletal model of the upper extremity. Muscle volumes obtained from MRI were used to scale PCSAs of five subjects, for whom the maximum forces they could exert in six different directions on a handle held by the hand were also recorded. The effect of PCSA scaling was evaluated by calculating the lowest maximum muscle stress (σmax, a constant for human skeletal muscle) required by the model to reproduce these forces. When the original cadaver-based PCSA-values were used, strongly different between-subject σmax-values were found (σmax=106.1±39.9 N cm(-2)). A relatively simple, uniform scaling routine reduced this variation substantially (σmax=69.4±9.4 N cm(-2)) and led to similar results to when a more detailed, muscle-specific scaling routine was used (σmax=71.2±10.8 N cm(-2)). Using subject-specific PCSA values to simulate an shoulder abduction task changed muscle force predictions for the subscapularis and the pectoralis major on average by 33% and 21%, respectively, but was <10% for all other muscles. The glenohumeral (GH) joint contact force changed less than 1.5% as a result of scaling. We conclude that individualisation of the model's strength can most easily be done by scaling PCSA with a single factor that can be derived from muscle volume data or, alternatively, from maximum force measurements. However, since PCSA scaling only marginally changed muscle and joint contact force predictions for submaximal tasks, the need for PCSA scaling remains debatable. PMID:26050956

  17. The association between hip muscle cross-sectional area, muscle strength, and bone mineral density.

    PubMed

    Ahedi, Harbeer; Aitken, Dawn; Scott, David; Blizzard, Leigh; Cicuttini, Flavia; Jones, Graeme

    2014-07-01

    Studies examining the association between muscle size, muscle strength, and bone mineral density (BMD) are limited. Thus, this study aimed to describe the association between hip muscles cross-sectional area (CSA), muscle strength, and BMD of the hip and spine. A total of 321 subjects from the Tasmanian Older Adult Cohort study with a right hip MRI scan conducted between 2004 and 2006 were included. Hip muscles were measured on MR images by OsiriX (Geneva) software measuring maximum muscle CSA (cm(2)) of gluteus maximus, obturator externus, gemelli, quadratus femoris, piriformis, pectineus, sartorius, and iliopsoas. Dual-energy X-ray absorptiometry measured total hip, femoral neck, and spine BMD, and lower limb muscle strength was assessed by dynamometer. Muscle CSA of the hip flexors (pectineus, sartorius, and iliopsoas) and the hip rotators, obturator externus, and quadratus femoris were associated with both total hip and femoral neck BMD (all p < 0.05). The associations between CSA of pectineus and sartorius and BMD were stronger in women (p = 0.01-0.001) compared to men (p = 0.12-0.54). Additionally, only gemelli CSA was associated with BMD of the spine (p = 0.002). Gluteus maximus and piriformis showed no relationship with BMD. CSA of most hip muscles (except gluteus maximus and gemelli) were positively associated with leg strength (p = 0.02 to <0.001). Lastly, leg strength was weakly associated with BMD (p = 0.11-0.007). Hip muscle CSA, and to a lesser extent muscle strength, were positively associated with hip BMD. These data suggest that both higher muscle mass and strength may contribute to the maintenance of bone mass and prevention of disease progression in older adults. PMID:24829114

  18. Variations in duodenal cross-sectional area during the interdigestive migrating motility complex.

    PubMed

    Gregersen, H; Kraglund, K; Djurhuus, J C

    1990-07-01

    A probe for measurement of intestinal cross-sectional area (CA) was used to elucidate variations of human gut CA during the interdigestive migrating motility complex (MMC). A balloon was inflated by saline at a pressure of 1 kPa, and variations of balloon CA (BCSA) were measured by means of the field-gradient principle. Duodenal phasic activity was measured by perfused side holes proximal to, distal to, and inside the balloon. In vitro characterization of probe performance showed that static measurement of BCSA was very accurate regardless of the configuration of the balloon. However, during dynamic measurements, BCSA was valid only for slow variations in BCSA due to resistance in the evacuation and inflation system. Eight duodenal MMCs were recorded. BCSA increased consistently from the start of phase I to the end of phase II from 72 (45-100) to 136 (87-154) mm2. During late phase II, a large BCSA increase was recorded. A positive correlation between the phasic activity level in phases I and II of MMC and maximal BCSA in duodenum was demonstrated (proximal P less than 0.01; distal P less than 0.05). BCSA during phase III was small but could not be estimated accurately because steady-state conditions were not obtained. The large BCSA in late phase II suggests a relaxation of the duodenal wall secondary to a decrease in smooth muscle tone. The results add evidence to previous findings of a low-resistance or large-capacitance situation in late phase II, observed as a large pancreaticobiliary excretion into the duodenum and an increased flow of duodenal contents. PMID:2372063

  19. Physiological cross-sectional area of human leg muscles based on magnetic resonance imaging

    NASA Technical Reports Server (NTRS)

    Fukunaga, T.; Roy, R. R.; Shellock, F. G.; Hodgson, J. A.; Day, M. K.; Lee, P. L.; Kwong-Fu, H.; Edgerton, V. R.

    1992-01-01

    Magnetic resonance imaging techniques were used to determine the physiological cross-sectional areas (PCSAs) of the major muscles or muscle groups of the lower leg. For 12 healthy subjects, the boundaries of each muscle or muscle group were digitized from images taken at 1-cm intervals along the length of the leg. Muscle volumes were calculated from the summation of each anatomical CSA (ACSA) and the distance between each section. Muscle length was determined as the distance between the most proximal and distal images in which the muscle was visible. The PCSA of each muscle was calculated as muscle volume times the cosine of the angle of fiber pinnation divided by fiber length, where published fiber length:muscle length ratios were used to estimate fiber lengths. The mean volumes of the major plantarflexors were 489, 245, and 140 cm3 for the soleus and medial (MG) and lateral (LG) heads of the gastrocnemius. The mean PCSA of the soleus was 230 cm2, about three and eight times larger than the MG (68 cm2) and LG (28 cm2), respectively. These PCSA values were eight (soleus), four (MG), and three (LG) times larger than their respective maximum ACSA. The major dorsiflexor, the tibialis anterior (TA), had a muscle volume of 143 cm2, a PCSA of 19 cm2, and an ACSA of 9 cm2. With the exception of the soleus, the mean fiber length of all subjects was closely related to muscle volume across muscles. The soleus fibers were unusually short relative to the muscle volume, thus potentiating its force potential.(ABSTRACT TRUNCATED AT 250 WORDS).

  20. Internal Jugular Vein Cross-Sectional Area Enlargement Is Associated with Aging in Healthy Individuals

    PubMed Central

    Magnano, Christopher; Belov, Pavel; Krawiecki, Jacqueline; Hagemeier, Jesper; Beggs, Clive; Zivadinov, Robert

    2016-01-01

    Background Internal jugular vein (IJV) narrowing has been implicated in central nervous system pathologies, however normal physiological age- and gender-related IJV variance in healthy individuals (HIs) has not been adequately assessed. Objectives We assessed the relationship between IJV cross-sectional area (CSA) and aging. Materials and Methods This study involved 193 HIs (63 males and 130 females) who received 2-dimensional magnetic resonance venography at 3T. The minimum CSA of the IJVs at cervical levels C2/C3, C4, C5/C6, and C7/T1 was obtained using a semi-automated contouring-thresholding technique. Subjects were grouped by decade. Pearson and partial correlation (controlled for cardiovascular risk factors, including hypertension, heart disease, smoking and body mass index) and analysis of variance analyses were used, with paired t-tests comparing side differences. Results Mean right IJV CSA ranges were: in males, 41.6 mm2 (C2/C3) to 82.0 mm2 (C7/T1); in females, 38.0 mm2 (C2/C3) to 62.3 mm2 (C7/T1), while the equivalent left side ranges were: in males, 28.0 mm2 (C2/C3) to 52.2 mm2 (C7/T1); in females, 27.2 mm2 (C2/C3) to 47.8 mm2 (C7/T1). The CSA of the right IJVs was significantly larger (p<0.001) than the left at all cervical levels. Controlling for cardiovascular risk factors, the correlation between age and IJV CSA was more robust in males than in the females for all cervical levels. Conclusions In HIs age, gender, hand side and cervical location all affect IJV CSA. These findings suggest that any definition of IJV stenosis needs to account for these factors. PMID:26895434

  1. Effect of exercise intervention on thigh muscle volume and anatomical cross-sectional areas--quantitative assessment using MRI.

    PubMed

    Hudelmaier, Martin; Wirth, Wolfgang; Himmer, Maria; Ring-Dimitriou, Susanne; Sänger, Alexandra; Eckstein, Felix

    2010-12-01

    The objective of this study was to evaluate the location-specific magnitudes of an exercise intervention on thigh muscle volume and anatomical cross-sectional area, using MRI. Forty one untrained women participated in strength, endurance, or autogenic training for 12 weeks. Axial MR images of the thigh were acquired before and after the intervention, using a T1-weighted turbo-spin-echo sequence (10 mm sections, 0.78 mm in-plane resolution). The extensor, flexor, adductor, and sartorius muscles were segmented between the femoral neck and the rectus femoris tendon. Muscle volumes were determined, and anatomical cross-sectional areas were derived from 3D reconstructions at 10% (proximal-to-distal) intervals. With strength training, the volume of the extensors (+3.1%), flexors (+3.5%), and adductors (+3.9%) increased significantly (P < 0.05) between baseline and follow-up, and with endurance training, the volume of the extensor (+3.7%) and sartorius (+5.1%) increased significantly (P < 0.05). No relevant or statistically significant change was observed with autogenic training. The greatest standardized response means were observed for the anatomical cross-sectional area in the proximal aspect (10-30%) of the thigh and generally exceeded those for muscle volumes. The study shows that MRI can be used to monitor location-specific effects of exercise intervention on muscle cross-sectional areas, with the proximal aspect of the thigh muscles being most responsive. PMID:20665894

  2. Relationship between paraspinal muscle cross-sectional area and relative proprioceptive weighting ratio of older persons with lumbar spondylosis.

    PubMed

    Ito, Tadashi; Sakai, Yoshihito; Nakamura, Eishi; Yamazaki, Kazunori; Yamada, Ayaka; Sato, Noritaka; Morita, Yoshifumi

    2015-07-01

    [Purpose] The purpose of this study was to examine the relationship between the paraspinal muscle cross-sectional area and the relative proprioceptive weighting ratio during local vibratory stimulation of older persons with lumbar spondylosis in an upright position. [Subjects] In all, 74 older persons hospitalized for lumbar spondylosis were included. [Methods] We measured the relative proprioceptive weighting ratio of postural sway using a Wii board while vibratory stimulations of 30, 60, or 240 Hz were applied to the subjects' paraspinal or gastrocnemius muscles. Back strength, abdominal muscle strength, and erector spinae muscle (L1/L2, L4/L5) and lumbar multifidus (L1/L2, L4/L5) cross-sectional areas were evaluated. [Results] The erector spinae muscle (L1/L2) cross-sectional area was associated with the relative proprioceptive weighting ratio during 60Hz stimulation. [Conclusion] These findings show that the relative proprioceptive weighting ratio compared to the erector spinae muscle (L1/L2) cross-sectional area under 60Hz proprioceptive stimulation might be a good indicator of trunk proprioceptive sensitivity.

  3. Reliability and Validity of Ultrasound Cross Sectional Area Measurements for Long-Duration Spaceflight

    NASA Technical Reports Server (NTRS)

    Scott, Jessica M.; Martin, David S.; Cunningham, David; Matz, Timothy; Caine, Timothy; Hackney, Kyle J.; Arzeno, Natalia; Ploutz-Snyder, Lori

    2010-01-01

    Limb muscle atrophy and the accompanying decline in function can adversely affect the performance of astronauts during mission-related activities and upon re-ambulation in a gravitational environment. Previous characterization of space flight-induced muscle atrophy has been performed using pre and post flight magnetic resonance imaging (MRI). In addition to being costly and time consuming, MRI is an impractical methodology for assessing in-flight changes in muscle size. Given the mobility of ultrasound (US) equipment, it may be more feasible to evaluate changes in muscle size using this technique. PURPOSE: To examine the reliability and validity of using a customized template to acquire panoramic ultrasound (US) images for determining quadriceps and gastrocnemius anatomical cross sectional area (CSA). METHODS: Vastus lateralis (VL), rectus femoris (RF), medial gastrocnemius (MG), and lateral gastrocnemius (LG) CSA were assessed in 10 healthy individuals (36+/-2 yrs) using US and MRI. Panoramic US images were acquired by 2 sonographers using a customized template placed on the thigh and calf and analyzed by the same 2 sonographers (CX50 Philips). MRI images of the leg were acquired while subjects were supine in a 1.5T scanner (Signa Horizon LX, General Electric) and were analyzed by 3 trained investigators. The average of the 2 US and 3 MRI values were used for validity analysis. RESULTS: High inter-experimenter reliability was found for both the US template and MRI analysis as coefficients of variation across muscles ranged from 2.4 to 4.1% and 2.8 to 3.8%, respectively. Significant correlations were found between US and MRI CSA measures (VL, r = 0.85; RF, r = 0.60; MG, r = 0.86; LG, r = 0.73; p < 0.05). Furthermore, the standard error of measurement between US and MRI ranged from 0.91 to 2.09 sq cm with high limits of agreement analyzed by Bland-Altman plots. However, there were significant differences between absolute values of MRI and US for all muscles

  4. Muscle activity, cross-sectional area, and density following passive standing and whole body vibration: A case series

    PubMed Central

    Masani, Kei; Alizadeh-Meghrazi, Milad; Sayenko, Dimitry G.; Zariffa, Jose; Moore, Cameron; Giangregorio, Lora; Popovic, Milos R.; Catharine Craven, B.

    2014-01-01

    Objective To investigate the effects of intermittent passive standing (PS) and whole body vibration (WBV) on the electromyography (EMG) activity, cross-sectional area, and density of lower extremity muscles in individuals with chronic motor complete spinal cord injury (SCI). Design Case series. Methods Seven adult men with chronic (≥2 years), thoracic motor complete (AIS A–B) SCI completed a 40-week course of thrice-weekly intermittent PS-WBV therapy, in a flexed knee posture (160°), for 45 minutes per session at a frequency of 45 Hz and 0.6–0.7 mm displacement using the WAVE® Pro Plate, with an integrated EasyStand™ standing frame. EMG was measured in major lower extremity muscles to represent muscle activity during PS-WBV. The cross-sectional area and density of the calf muscles were measured using peripheral quantitative computed tomography at the widest calf cross-section (66% of the tibia length) at pre- and post-intervention. All measured variables were compared between the pre- and post-intervention measurements to assess change after the PS-WBV intervention. Results PS-WBV acutely induced EMG activity in lower extremity muscles of SCI subjects. No significant changes in lower extremity EMG activity, muscle cross-sectional area, or density were observed following the 40-week intervention. Conclusions Although acute exposure to PS-WBV can induce electrophysiological activity of lower extremity muscles during PS in men with motor complete SCI, the PS-WBV intervention for 40 weeks was not sufficient to result in enhanced muscle activity, or to increase calf muscle cross-sectional area or density. PMID:25059652

  5. The Association between the Cross-Sectional Area of the Dural Sac and Low Back Pain in a Large Population: The Wakayama Spine Study

    PubMed Central

    Iwahashi, Hiroki; Yoshimura, Noriko; Hashizume, Hiroshi; Yamada, Hiroshi; Oka, Hiroyuki; Matsudaira, Ko; Shinto, Kazunori; Ishimoto, Yuyu; Nagata, Keiji; Teraguchi, Masatoshi; Kagotani, Ryohei; Muraki, Shigeyuki; Akune, Toru; Tanaka, Sakae; Kawaguchi, Hiroshi; Nakamura, Kozo; Minamide, Akihito; Nakagawa, Yukihiro; Yoshida, Munehito

    2016-01-01

    Objective The purpose of this study was to evaluate the relations between the degree of encroachment, measured as the cross-sectional area of the dural sac, and low back pain in a large population. Methods In this cross-sectional study, data from 802 participants (247 men, 555 women; mean age, 63.5 years) were analyzed. The measurement of the cross-sectional area of the dural sac from the level of L1/2 to L4/5 was taken using axial T2-weighted images. The minimum cross-sectional area was defined as the cross-sectional area of the dural sac at the most constricted level in the examined spine. Participants were divided into three groups according to minimum cross-sectional area measurement quartiles (less than the first quartile, between the first and third quartiles, and greater than the third quartile). A multivariate logistic regression analysis was used to estimate the association between the minimum cross-sectional area and the prevalence of low back pain. Results The mean minimum cross-sectional area was 117.3 mm2 (men: 114.4 mm2; women: 118.6 mm2). A logistic regression analysis adjusted for age, sex, body mass index, and other confounding factors, including disc degeneration, showed that a narrow minimum cross-sectional area (smaller than the first quartile) was significantly associated with low back pain (odds ratio, 1.78; 95% confidence interval, 1.13–2.80 compared to the wide minimum cross-sectional area group: minimum cross-sectional area greater than the third quartile measured). Conclusion This study showed that a narrow dural sac cross-sectional area was significantly associated with the presence of low back pain after adjustment for age, sex, and body mass index. Further investigations that include additional radiographic findings and psychological factors will continue to elucidate the causes of low back pain. PMID:27486899

  6. A double fluorescence staining protocol to determine the cross-sectional area of myofibers using image analysis

    NASA Technical Reports Server (NTRS)

    Mozdziak, P. E.; Fassel, T. A.; Schultz, E.; Greaser, M. L.; Cassens, R. G.

    1996-01-01

    A double fluorescence staining protocol was developed to facilitate computer based image analysis. Myofibers from experimentally treated (irradiated) and control growing turkey skeletal muscle were labeled with the anti-myosin antibody MF-20 and detected using fluorescein-5-isothiocyanate (FITC). Extracellular material was stained with concanavalin A (ConA)-Texas red. The cross-sectional area of the myofibers was determined by calculating the number of pixels (0.83 mu m(2)) overlying each myofiber after subtracting the ConA-Texas red image from the MF-20-FITC image for each region of interest. As expected, myofibers in the irradiated muscle were smaller (P < 0.05) than those in the non-irradiated muscle. This double fluorescence staining protocol combined with image analysis is accurate and less labor-intensive than classical procedures for determining the cross-sectional area of myofibers.

  7. Efficacy of Percutaneous Epidural Neuroplasty Does Not Correlate with Dural Sac Cross-Sectional Area in Single Level Disc Disease

    PubMed Central

    Ji, Gyu Yeul; Oh, Chang Hyun; Moon, Bongju; Choi, Seung Hyun; Yoon, Young Sul; Kim, Keung Nyun

    2015-01-01

    Purpose Percutaneous epidural neuroplasty (PEN) is a minimally invasive treatment. The efficacy of PEN has been relatively well investigated; however, the relationship between the clinical effectiveness of PEN and the severity of spinal canal stenosis by disc material has not yet been established. The purpose of this study was to compare clinical outcomes of PEN according to the dural sac cross-sectional area in single level disc disease. Materials and Methods This study included 363 patients with back pain from single level disc disease with and without radiculopathy. Patients were categorized into groups according to spinal canal compromise by disc material: Category 1, less or more than 50%; and Category 2, three subgroups with lesser than a third, between a third and two thirds, and more than two thirds. Clinical outcomes were assessed according to the Visual Analog Scale (VAS) score for back pain and leg pain and Odom's criteria at 1, 3, 6, 12, and 24 months after treatment. Results The demographic data showed no difference between groups according to spinal canal compromise by disc material except age (older age correlated with more spinal canal compromise). The dural sac cross-sectional area did not correlate with the VAS scores for back and leg pain after PEN in single level disc disease in Groups 1 and 2. Odom's criteria after PEN were also not different according to dural sac cross-sectional area by disc material. Conclusion PEN is an effective procedure in treating single level lumbar disc herniation without affecting dural sac cross-sectional area. PMID:25837174

  8. Computer image analysis for measuring lean and fatty areas in cross-sectioned dry-cured hams.

    PubMed

    Carnier, P; Gallo, L; Romani, C; Sturaro, E; Bondesan, V

    2004-03-01

    The aims of this study were 1) to apply computer image analysis to obtain measures of lean and fatty areas on the cross section of dry-cured hams, 2) to investigate variation of these measures, and 3) to evaluate reproducibility and repeatability of these techniques. Traits of concern were the cross-sectional area (SA), lean, or muscles, area (LA), and the fatty area (FA) centered on the cross section and surrounded by biceps femoris, semimembranosus, semitendinosus, and quadriceps femoris, as well as the FA-to-SA ratio (FESR). Hams were obtained from crossbred pigs (n = 279) slaughtered at 9 mo of age (mean BW of 169 +/- 17 kg). Digital images of the cross section of dry-cured hams were captured using standardized procedures. Three replicated measures of areas were collected by three operators using three image analysis techniques (automatic, automatic-assisted, and manual). Variance components were estimated using a linear model that included slaughter group, gender, and gender x slaughter group as fixed effects and operators, pig, and operator x pig as random effects. Statistical analyses considered all measures (n = 7,533) or measures collected after reinstruction of all operators for spatial calibration of the analysis system (n = 4,428). Average SA, LA, FA, and FESR were 350 cm2, 220 cm2, 8.7 cm2, and 2.5%, respectively. Variability of FA (CV = 42%) and of FESR (CV = 39%) was four times greater than that of SA and LA. Slaughter group, pig, operator, and operator x pig effects were the most (P < 0.01) important sources of variation of measures. Correlations between measures obtained with different techniques were greater (P < 0.01) than 0.90, with the exception of LA measures. Coefficients of reproducibility for SA and LA ranged from 87 to 94%, whereas those for FA and FESR ranged from 88 to 98%. Coefficients of repeatability ranged from 92 to 99%. Automatic-assisted and manual methods provided more reproducible and repeatable measures than the automatic

  9. The african origin of complex projectile technology: an analysis using tip cross-sectional area and perimeter.

    PubMed

    Sisk, Matthew L; Shea, John J

    2011-01-01

    Despite a body of literature focusing on the functionality of modern and stylistically distinct projectile points, comparatively little attention has been paid to quantifying the functionality of the early stages of projectile use. Previous work identified a simple ballistics measure, the Tip Cross-Sectional Area, as a way of determining if a given class of stone points could have served as effective projectile armatures. Here we use this in combination with an alternate measure, the Tip Cross-Sectional Perimeter, a more accurate proxy of the force needed to penetrate a target to a lethal depth. The current study discusses this measure and uses it to analyze a collection of measurements from African Middle Stone Age pointed stone artifacts. Several point types that were rejected in previous studies are statistically indistinguishable from ethnographic projectile points using this new measure. The ramifications of this finding for a Middle Stone Age origin of complex projectile technology is discussed.

  10. The African Origin of Complex Projectile Technology: An Analysis Using Tip Cross-Sectional Area and Perimeter

    PubMed Central

    Sisk, Matthew L.; Shea, John J.

    2011-01-01

    Despite a body of literature focusing on the functionality of modern and stylistically distinct projectile points, comparatively little attention has been paid to quantifying the functionality of the early stages of projectile use. Previous work identified a simple ballistics measure, the Tip Cross-Sectional Area, as a way of determining if a given class of stone points could have served as effective projectile armatures. Here we use this in combination with an alternate measure, the Tip Cross-Sectional Perimeter, a more accurate proxy of the force needed to penetrate a target to a lethal depth. The current study discusses this measure and uses it to analyze a collection of measurements from African Middle Stone Age pointed stone artifacts. Several point types that were rejected in previous studies are statistically indistinguishable from ethnographic projectile points using this new measure. The ramifications of this finding for a Middle Stone Age origin of complex projectile technology is discussed. PMID:21755048

  11. Alternative method for estimating the cross-sectional interpolation errors of discharge measurements using the velocity-area method

    NASA Astrophysics Data System (ADS)

    Despax, Aurélien; Perret, Christian; Garçon, Rémy; Hauet, Alexandre; Belleville, Arnaud; Le Coz, Jérôme; Favre, Anne-Catherine

    2016-04-01

    Quantifying the quality of discharge measurements by uncertainty analysis is a challenge in the hydrometric community. Discharge measurements are the first step to produce hydrometric data which are used in many hydrological studies like design of hydraulic structures or calibration of hydrological models for flood forecasting and warning. Thus associated uncertainty has to be estimated carefully. The velocity-area method is a common approach for estimating river discharge. It consists in integrating depths and point velocities through the cross-section. Due to the limited number of point measurements, the quality of the measurement depends mainly on the sampling strategy. Different methods of uncertainty estimation are available in the literature (ISO 748, Q+ and IVE). The main uncertainty component, noted um, is often related to the cross-sectional interpolation errors. However the computation of this term according to these approaches does not evaluate both the sampling strategy and the complexity of the cross-section. The FLAURE method (FLow Analog UnceRtainty Estimation) includes a new methodology to estimate this term. It is based on the study of high-resolution stream-gaugings (i.e. reference stream-gaugings made with a high number of verticals). The high-resolution measurements are first subsampled by reducing the number of verticals to generate a sample of realistic stream-gaugings. A statistical analysis is performed to estimate the um component and then a sampling quality index is defined. For each reference stream-gauging, it leads to a curve of um component as a function of the sampling quality index. This set of curves is finally used to compute the um component of any routine stream-gauging. Curves are then selected according to the similitude between the routine stream-gauging and reference stream-gaugings. The similitude between the routine stream-gauging and reference stream-gaugings is evaluated thanks to the Nash criteria computed on lateral

  12. Force per cross-sectional area from molecules to muscles: a general property of biological motors

    PubMed Central

    Meyer-Vernet, Nicole

    2016-01-01

    We propose to formally extend the notion of specific tension, i.e. force per cross-sectional area—classically used for muscles, to quantify forces in molecular motors exerting various biological functions. In doing so, we review and compare the maximum tensions exerted by about 265 biological motors operated by about 150 species of different taxonomic groups. The motors considered range from single molecules and motile appendages of microorganisms to whole muscles of large animals. We show that specific tensions exerted by molecular and non-molecular motors follow similar statistical distributions, with in particular, similar medians and (logarithmic) means. Over the 1019 mass (M) range of the cell or body from which the motors are extracted, their specific tensions vary as Mα with α not significantly different from zero. The typical specific tension found in most motors is about 200 kPa, which generalizes to individual molecular motors and microorganisms a classical property of macroscopic muscles. We propose a basic order-of-magnitude interpretation of this result. PMID:27493785

  13. The subsurface cross section resistivity using magnetotelluric method in Pelabuhan Ratu area, West Java, implication for geological hazard mitigation

    NASA Astrophysics Data System (ADS)

    Gaffar, Eddy Z.

    2016-02-01

    Pelabuhan Ratu area is located on the south coast of West Java. Pelabuhan Ratu area's rapid development and population growth were partly stimulated by the Indonesian Government Regulation No. 66 the year 1998 that made Pelabuhan Ratu the capital city of the district of Sukabumi. Because of this fact, it is very important to create a geological hazard mitigation plan for the area. Pelabuhan Ratu were passed by two major faults: Cimandiri fault in the western and Citarik fault in the eastern. Cimandiri fault starts from the upstream of Cimandiri River to the southern of Sukabumi and Cianjur city. While Citarik fault starts from the Citarik River until the Salak Mountain. These two faults needs to be observed closely as they are prone to cause earthquake in the area. To mitigate earthquake that is estimated will occur at Cimandiri fault or the Citarik fault, the Research Center for Geotechnology LIPI conducted research using Magnetotelluric (MT) method with artificial Phoenix MT tool to determine the cross-section resistivity of the Pelabuhan Ratu and the surrounding area. Measurements were taken at 40 points along the highway towards Jampang to Pelabuhan Ratu, and to Bandung towards Cibadak with a distance of less than 500 meters between the measuring points. Measurement results using this tool will generate AMT cross-section resistivity to a depth of 1500 meters below the surface. Cross-section resistivity measurement results showed that there was a layer of rock with about 10 Ohm-m to 1000 Ohm-m resistivity. Rocks with resistivity of 10 Ohm-m was interpreted as conductive rocks that were loose or sandstone containing water. If an earthquake to occur in this area, it will lead to a strong movement and liquefaction that will destroy buildings and potentially cause casualties in this area.

  14. Cross-Sectional Data for Selected Reaches of the Chattahoochee River within the Chattahoochee River National Recreation Area, Georgia, 2004

    USGS Publications Warehouse

    Dalton, Melinda S.

    2006-01-01

    This report presents hydrologic data for selected reaches of the Chattahoochee River within the Chattahoochee River National Recreation Area (CRNRA). Data about transect location, width, depth, and velocity of flow for selected reaches of the river are presented in tabular form. The tables contain measurements collected from shoal and run habitats identified as critical sites for the CRNRA. In shoal habitats, measurements were collected while wading using a digital flowmeter and laser range finder. In run habitats, measurements were collected using acoustic Doppler current profiling. Fifty-three transects were established in six reaches throughout the CRNRA; 24 in shoal habitat, 26 in run habitat, and 3 in pool habitat. Illustrations in this report contain information about study area location, hydrology, transect locations, and cross-sectional information. A study area location figure is followed by figures identifying locations of transects within each individual reach. Cross-sectional information is presented for each transect, by reach, in a series of graphs. The data presented herein can be used to complete preliminary habitat assessments for the Chattahoochee River within the CRNRA. These preliminary assessments can be used to identify reaches of concern for future impacts associated with continual development in the Metropolitan Atlanta area and potential water allocation agreements between Georgia, Florida, and Alabama.

  15. Constructing river stage-discharge rating curves using remotely sensed river cross-sectional inundation areas and river bathymetry

    NASA Astrophysics Data System (ADS)

    Pan, Feifei; Wang, Cheng; Xi, Xiaohuan

    2016-09-01

    Remote sensing from satellites and airborne platforms provides valuable data for monitoring and gauging river discharge. One effective approach first estimates river stage from satellite-measured inundation area based on the inundation area-river stage relationship (IARSR), and then the estimated river stage is used to compute river discharge based on the stage-discharge rating (SDR) curve. However, this approach is difficult to implement because of a lack of data for constructing the SDR curves. This study proposes a new method to construct the SDR curves using remotely sensed river cross-sectional inundation areas and river bathymetry. The proposed method was tested over a river reach between two USGS gauging stations, i.e., Kingston Mines (KM) and Copperas Creek (CC) along the Illinois River. First a polygon over each of two cross sections was defined. A complete IARSR curve was constructed inside each polygon using digital elevation model (DEM) and river bathymetric data. The constructed IARSR curves were then used to estimate 47 river water surface elevations at each cross section based on 47 river inundation areas estimated from Landsat TM images collected during 1994-2002. The estimated water surface elevations were substituted into an objective function formed by the Bernoulli equation of gradually varied open channel flow. A nonlinear global optimization scheme was applied to solve the Manning's coefficient through minimizing the objective function value. Finally the SDR curve was constructed at the KM site using the solved Manning's coefficient, channel cross sectional geometry and the Manning's equation, and employed to estimate river discharges. The root mean square error (RMSE) in the estimated river discharges against the USGS measured river discharges is 112.4 m3/s. To consider the variation of the Manning's coefficient in the vertical direction, this study also suggested a power-law function to describe the vertical decline of the Manning

  16. Area deprivation and its association with health in a cross-sectional study: are the results biased by recent migration?

    PubMed Central

    Piro, Fredrik Niclas; Næss, Øyvind; Claussen, Bjørgulf

    2007-01-01

    Background The association between area deprivation and health has mostly been examined in cross-sectional studies or prospective studies with short follow-up. These studies have rarely taken migration into account. This is a possible source of misclassification of exposure, i.e. an unknown number of study participants are attributed an exposure of area deprivation that they may have experienced too short for it to have any influence. The aim of this article was to examine to what extent associations between area deprivation and health outcomes were biased by recent migration. Methods Based on data from the Oslo Health Study, a cross-sectional study conducted in 2000 in Oslo, Norway, we used six health outcomes (self rated health, mental health, coronary heart disease, chronic obstructive pulmonary disease, smoking and exercise) and considered migration nine years prior to the study conduct. Migration into Oslo, between the areas of Oslo, and the changes in area deprivation during the period were taken into account. Associations were investigated by multilevel logistic regression analyses. Results After adjustment for individual socio-demographic variables we found significant associations between area deprivation and all health outcomes. Accounting for migration into Oslo and between areas of Oslo did not change these associations much. However, the people who migrated into Oslo were younger and had lower prevalences of unfavourable health outcomes than those who were already living in Oslo. But since they were evenly distributed across the area deprivation quintiles, they had little influence on the associations between area deprivation and health. Evidence of selective migration within Oslo was weak, as both moving up and down in the deprivation hierarchy was associated with significantly worse health than not moving. Conclusion We have documented significant associations between area deprivation and health outcomes in Oslo after adjustment for socio

  17. Primary pressure standard based on piston-cylinder assemblies. Calculation of effective cross sectional area based on rarefied gas dynamics

    NASA Astrophysics Data System (ADS)

    Sharipov, Felix; Yang, Yuanchao; Ricker, Jacob E.; Hendricks, Jay H.

    2016-10-01

    Currently, the piston-cylinder assembly known as PG39 is used as a primary pressure standard at the National Institute of Standards and Technology (NIST) in the range of 20 kPa to 1 MPa with a standard uncertainty of 3× {{10}-6} as evaluated in 2006. An approximate model of gas flow through the crevice between the piston and sleeve contributed significantly to this uncertainty. The aim of this work is to revise the previous effective cross sectional area of PG39 and its uncertainty by carrying out more exact calculations that consider the effects of rarefied gas flow. The effective cross sectional area is completely determined by the pressure distribution in the crevice. Once the pressure distribution is known, the elastic deformations of both piston and sleeve are calculated by finite element analysis. Then, the pressure distribution is recalculated iteratively for the new crevice dimension. As a result, a new value of the effective area is obtained with a relative difference of 3× {{10}-6} from the previous one. Moreover, this approach allows us to reduce significantly the standard uncertainty related to the gas flow model so that the total uncertainty is decreased by a factor of three.

  18. Cross-sectional area measurement of the coronary arteries using CT angiography at the level of the bifurcation: is there a relationship?

    PubMed Central

    Verim, Samet; Öztürk, Ersin; Küçük, Uğur; Kara, Kemal; Sağlam, Muzaffer; Kardeşoğlu, Ejder

    2015-01-01

    PURPOSE Our aim was to determine whether there is a correlation between cross-sectional areas of the left main coronary artery (LMCA), left anterior descending artery (LAD), and circumflex artery (CX) in normal cases using coronary CT angiography. METHOD Examinations of 180 patients (119 men and 61 women) were selected among 2248 consecutive coronary CT angiography studies. Cross-sectional areas of LMCA, LAD, and CX were measured at the level of bifurcation. Correlation between age, height, and body mass index and coronary artery cross-sectional areas was investigated and possibility of formulating a correlation between the cross-sectional areas of LMCA, LAD, and CX was explored. RESULTS Mean cross-sectional areas of LMCA, LAD, and CX were found as 17.4±3.9 mm2, 12.5±3.1 mm2, and 10.5±3.0 mm2, respectively. While cross-sectional areas of LMCA and LAD were significantly larger in men, no significant difference was found between the sectional areas of CX in men and women. A multiple regression analysis was conducted to elucidate the relationship between the cross-sectional areas of LMCA LAD, and CX. Our analysis showed that the relationship between LMCA, LAD, and CX cross-sectional areas can be formulated as follows: LMCA=3.870 + 0.718×LAD + 0.434×CX. CONCLUSION There is a correlation between the cross-sectional areas of LMCA, LAD, and CX at the level of bifurcation, and this correlation can be expressed with a formula. PMID:26359878

  19. Are Sport-Specific Profiles of Tendon Stiffness and Cross-Sectional Area Determined by Structural or Functional Integrity?

    PubMed Central

    Rieder, Florian; Kösters, Alexander; Müller, Erich; Seynnes, Olivier R.

    2016-01-01

    The present study aimed to determine whether distinct sets of tendon properties are seen in athletes engaged in sports with contrasting requirements for tendon function and structural integrity. Patellar and Achilles tendon morphology and force-deformation relation were measured by combining ultrasonography, electromyography and dynamometry in elite ski jumpers, distance runners, water polo players and sedentary individuals. Tendon cross-sectional area normalized to body mass2/3 was smaller in water polo players than in other athletes (patellar and Achilles tendon; -28 to -24%) or controls (patellar tendon only; -9%). In contrast, the normalized cross-sectional area was larger in runners (patellar tendon only; +26%) and ski jumpers (patellar and Achilles tendon; +21% and +13%, respectively) than in controls. Tendon stiffness normalized to body mass2/3 only differed in ski jumpers, compared to controls (patellar and Achilles tendon; +11% and +27%, respectively) and to water polo players (Achilles tendon only; +23%). Tendon size appears as an adjusting variable to changes in loading volume and/or intensity, possibly to preserve ultimate strength or fatigue resistance. However, uncoupled morphological and mechanical properties indicate that functional requirements may also influence tendon adaptations. PMID:27362657

  20. Estimation of unemployment rates using small area estimation model by combining time series and cross-sectional data

    NASA Astrophysics Data System (ADS)

    Muchlisoh, Siti; Kurnia, Anang; Notodiputro, Khairil Anwar; Mangku, I. Wayan

    2016-02-01

    Labor force surveys conducted over time by the rotating panel design have been carried out in many countries, including Indonesia. Labor force survey in Indonesia is regularly conducted by Statistics Indonesia (Badan Pusat Statistik-BPS) and has been known as the National Labor Force Survey (Sakernas). The main purpose of Sakernas is to obtain information about unemployment rates and its changes over time. Sakernas is a quarterly survey. The quarterly survey is designed only for estimating the parameters at the provincial level. The quarterly unemployment rate published by BPS (official statistics) is calculated based on only cross-sectional methods, despite the fact that the data is collected under rotating panel design. The study purpose to estimate a quarterly unemployment rate at the district level used small area estimation (SAE) model by combining time series and cross-sectional data. The study focused on the application and comparison between the Rao-Yu model and dynamic model in context estimating the unemployment rate based on a rotating panel survey. The goodness of fit of both models was almost similar. Both models produced an almost similar estimation and better than direct estimation, but the dynamic model was more capable than the Rao-Yu model to capture a heterogeneity across area, although it was reduced over time.

  1. Quantitative ultrasound method for assessing stress-strain properties and the cross-sectional area of Achilles tendon

    NASA Astrophysics Data System (ADS)

    Du, Yi-Chun; Chen, Yung-Fu; Li, Chien-Ming; Lin, Chia-Hung; Yang, Chia-En; Wu, Jian-Xing; Chen, Tainsong

    2013-12-01

    The Achilles tendon is one of the most commonly observed tendons injured with a variety of causes, such as trauma, overuse and degeneration, in the human body. Rupture and tendinosis are relatively common for this strong tendon. Stress-strain properties and shape change are important biomechanical properties of the tendon to assess surgical repair or healing progress. Currently, there are rather limited non-invasive methods available for precisely quantifying the in vivo biomechanical properties of the tendons. The aim of this study was to apply quantitative ultrasound (QUS) methods, including ultrasonic attenuation and speed of sound (SOS), to investigate porcine tendons in different stress-strain conditions. In order to find a reliable method to evaluate the change of tendon shape, ultrasound measurement was also utilized for measuring tendon thickness and compared with the change in tendon cross-sectional area under different stress. A total of 15 porcine tendons of hind trotters were examined. The test results show that the attenuation and broadband ultrasound attenuation decreased and the SOS increased by a smaller magnitude as the uniaxial loading of the stress-strain upon tendons increased. Furthermore, the tendon thickness measured with the ultrasound method was significantly correlated with tendon cross-sectional area (Pearson coefficient = 0.86). These results also indicate that attenuation of QUS and ultrasonic thickness measurement are reliable and potential parameters for assessing biomechanical properties of tendons. Further investigations are needed to warrant the application of the proposed method in a clinical setting.

  2. Is the Cross-sectional Area after Unilateral Open Door Laminoplasty Wider than that after Midline Splitting Laminoplasty ? : Mathematical Approach

    PubMed Central

    Kim, Eun-Sang; Eoh, Whan; Jang, Il Tae; Choi, Sang-Eun

    2013-01-01

    Objective The aim of this study was to compare geometrically cross-sectional areas of two different laminoplasty techniques in same opening size. Some investigators have studied the expanded areas of the two different techniques using imaging study. Although it is unclear that postoperative spinal canal is correlated with the surgical outcome we just focused on mathematical and geometrical correlation of the expandable area with surgical opening size in different laminoplasty techniques. Methods To predict the expandable area by a midline splitting technique and a unilateral open door technique, we placed an imaginary isosceles triangle in the spinal canal and drew graphs for the equation of the expandable areas in same opening size using the Pythagorean theorem and mathematical program. To substitute the constant figures of mathematical formula we estimated the normal cervical spine CT scans of 50 Korean adults. Results We subtracted the imaginary triangle from the spinal canal and were left with the remaining area of the spinal canal that was not changed before and after surgery. In same opening size the expandable area by the midline splitting technique was same but slightly wider than the unilateral open door technique, irrespective of the triangular shape. For a normal isosceles triangle the results were the same. Conclusion Using mathematical proof, the expandable area after the midline splitting technique was same but slightly larger than that after the unilateral open door technique, irrespective of the size of the lamina opening. PMID:24891855

  3. Pilot study for reconstruction of soft tissues: muscle cross-sectional area of the forearm estimated from cortical bone for a Neolithic sample.

    PubMed

    Slizewski, Astrid; Burger-Heinrich, Eva; Francken, Michael; Wahl, Joachim; Harvati, Katerina

    2014-06-01

    On a basis of a method for muscle cross-sectional area estimation from cortical bone area that was previously developed (Slizewski et al. Anat Rec 2013; 296:1695-1707), we reconstructed muscle cross-sectional area at 65% of radius length for a sample of Neolithic human remains from the Linear Pottery Culture (ca. 5,700-4,900 years BC). Muscle cross-sectional area estimations for the Neolithic sample were compared to in vivo measurements from a recent human sample. Results demonstrate that the Neolithic individuals had larger muscle cross-sectional area relative to radius length than the contemporary humans and that their forearms were more muscular and robust. We also found significant differences in relative muscle cross-sectional area between Neolithic and recent children that indicate different levels of physical stress and isometric activities. Our results fit into the framework of studies previously published about the sample and the Linear Pottery Culture. Therefore, the new approach was successfully applied to an archaeological sample for the first time here. Results of our pilot study indicate that muscle cross-sectional area estimation could in the future supplement other anthropological methods currently in use for the analysis of postcranial remains.

  4. Does car ownership reflect socio-economic disadvantage in rural areas? A cross-sectional geographical study in Wales, UK.

    PubMed

    Christie, S M; Fone, D L

    2003-03-01

    It is widely believed that area-based deprivation indices that include the car ownership census variable are poor indicators of deprivation in rural areas since car ownership is a necessity of rural life. In this cross-sectional geographical study, we assess whether the relation between lack of car ownership and socio-economic deprivation varies between urban and rural enumeration districts of Wales, UK. We classified the 6376 census enumeration districts in Wales into rural (1636, 26%) and urban (4740, 74%), using the Office for National Statistics' classification based on land use. Rank correlation coefficients between the proportion of households with no car and a range of other proxy deprivation census variables were strongly positive in urban and the most densely populated rural enumeration districts. However, these correlations were weaker in sparsely populated rural enumeration districts, with a declining trend across deciles of population density. Exclusion of the car ownership variable from the Townsend index of deprivation re-categorized rural enumeration districts as more deprived and urban enumeration districts as less deprived compared with the standard Townsend index. Our results suggest that lack of car ownership is a poor proxy for social deprivation in the most sparsely populated rural areas of Wales, and therefore, deprivation indices that include the car ownership variable are less valid for use in rural areas. PMID:12802977

  5. Viscoelastic properties of healthy achilles tendon are independent of isometric plantar flexion strength and cross-sectional area.

    PubMed

    Suydam, Stephen M; Soulas, Elizabeth M; Elliott, Dawn M; Silbernagel, Karin Gravare; Buchanan, Thomas S; Cortes, Daniel H

    2015-06-01

    Changes in tendon viscoelastic properties are observed after injuries and during healing as a product of altered composition and structure. Continuous Shear Wave Elastography is a new technique measuring viscoelastic properties of soft tissues using external shear waves. Tendon has not been studied with this technique, therefore, the aims of this study were to establish the range of shear and viscosity moduli in healthy Achilles tendons, determine bilateral differences of these parameters and explore correlations of viscoelasticity to plantar flexion strength and tendon area. Continuous Shear Wave Elastography was performed over the free portion of both Achilles tendons from 29 subjects. Isometric plantar flexion strength and cross sectional area were measured. The average shear and viscous moduli was 83.2 kPa and 141.0 Pa-s, respectively. No correlations existed between the shear or viscous modulus and area or strength. This indicates that viscoelastic properties can be considered novel, independent biomarkers. The shear and viscosity moduli were bilaterally equivalent (p = 0.013, 0.017) which allows determining pathologies through side-to-side deviations. The average bilateral coefficient of variation was 7.2% and 9.4% for shear and viscosity modulus, respectively. The viscoelastic properties of the Achilles tendon may provide an unbiased, non-subjective rating system of tendon recovery and optimizing treatment strategies.

  6. Viscoelastic Properties of Healthy Achilles Tendon are Independent of Isometric Plantar Flexion Strength and Cross-Sectional Area

    PubMed Central

    Suydam, Stephen M.; Soulas, Elizabeth M.; Elliott, Dawn M.; Silbernagel, Karin Gravare; Buchanan, Thomas S.; Cortes, Daniel H.

    2015-01-01

    Changes in tendon viscoelastic properties are observed after injuries and during healing as a product of altered composition and structure. Continuous Shear Wave Elastography is a new technique measuring viscoelastic properties of soft tissues using external shear waves. Tendon has not been studied with this technique, therefore, the aims of this study were to establish the range of shear and viscosity moduli in healthy Achilles tendons, determine bilateral differences of these parameters and explore correlations of viscoelasticity to plantar flexion strength and tendon area. Continuous Shear Wave Elastography was performed over the free portion of both Achilles tendons from 29 subjects. Isometric plantar flexion strength and cross sectional area were measured. The average shear and viscous moduli was 83.2kPa and 141.0Pa-s, respectively. No correlations existed between the shear or viscous modulus and area or strength. This indicates that viscoelastic properties can be considered novel, independent biomarkers. The shear and viscosity moduli were bilaterally equivalent (p=0.013,0.017) which allows determining pathologies through side-to-side deviations. The average bilateral coefficient of variation was 7.2% and 9.4% for shear and viscosity modulus, respectively. The viscoelastic properties of the Achilles tendon may provide an unbiased, non-subjective rating system of tendon recovery and optimizing treatment strategies. PMID:25882209

  7. Cross-sectional study of ethnic differences in the utility of area deprivation measures to target socioeconomically deprived individuals.

    PubMed

    Baker, Jessica; Mitchell, Richard; Pell, Jill

    2013-05-01

    Area deprivation measures provide a pragmatic tool for targeting public health interventions at socioeconomically deprived individuals. Ethnic minority groups in the UK experience higher levels of socioeconomic deprivation and certain associated diseases than the White population. The aim of this study was to explore ethnic differences in the utility of area deprivation measures as a tool for targeting socioeconomically deprived individuals. We carried out a cross-sectional study using the Health Survey for England 2004. 7208 participants aged 16-64 years from the four largest ethnic groups in England (White, Indian, Pakistani and Black Caribbean) were included. The main outcome measures were percentage agreement, sensitivity and positive predictive value (PPV) of area deprivation, measured using Index of Multiple Deprivation 2004, in relation to individual socioeconomic position (measured by education, occupation, income, housing tenure and car access). We found that levels of both area and individual deprivation were higher in the Pakistani and Black Caribbean groups compared to the White group. Across all measures, agreement was lower in the Pakistani (50.9-63.4%) and Black Caribbean (61.0-70.1%) groups than the White (67.2-82.4%) group. However, sensitivity was higher in the Pakistani (0.56-0.64) and Black Caribbean (0.59-0.66) groups compared to the White group (0.24-0.38) and PPV was at least as high. The results for the Indian group were intermediate. We conclude that, in spite of lower agreement, area deprivation is better at identifying individual deprivation in ethnic minority groups. There was no evidence that area based targeting of public health interventions will disadvantage ethnic minority groups.

  8. Prevalence and Risk Factors of Hypertension in Urban Areas of Cameroon: A Nationwide Population-Based Cross-Sectional Study.

    PubMed

    Kingue, Samuel; Ngoe, Constant Ndong; Menanga, Alain Patrick; Jingi, Ahmadou M; Noubiap, Jean Jacques N; Fesuh, Betrand; Nouedoui, Christophe; Andze, Gervais; Muna, Walinjom F T

    2015-10-01

    Accurate estimates of the prevalence rate of hypertension and determinants in Cameroon are crucial to inform efficient prevention and control policies. The authors carried out a cluster-specific cross-sectional survey in urban areas of the 10 regions of Cameroon to assess the prevalence and risk factors of hypertension in Cameroonian adults using the WHO STEPwise approach to Surveillance (STEPS). Sociodemographic data were collected and blood pressure and glycemia were measured using standardized methods. Participants were adults of both sexes aged 16 years or older. A total of 15,470 participants were surveyed. The age-standardized prevalence rate of hypertension was 29.7%. The awareness rate was 14.1%. Independent correlates of hypertension included higher age, male sex, obesity, hyperglycemia, and living in the Savannah zone. The prevalence of hypertension is high in urban areas of Cameroon, with very low awareness. Prevention and control strategies should emphasize on improvement and vulgarization of population opportunistic screening and education. PMID:26140673

  9. Effects of Stabilization Exercise Using a Ball on Mutifidus Cross-Sectional Area in Patients with Chronic Low Back Pain

    PubMed Central

    Chung, SinHo; Lee, JuSang; Yoon, JangSoon

    2013-01-01

    The purpose of this study was to compare the effects of lumbar stabilization exercises using balls to the effects of general lumbar stabilization exercises with respect to changes in the cross section of the multifidus (MF), weight bearing, pain, and functional disorders in patients with non-specific chronic low back pain. Twelve patients participated in either a 8 week (3 days per week) stabilization exercise program using balls and control group (n = 12). The computer tomography (CT) was used to analyze MF cross-sectional areas (CSA) and Tetrax balancing scale was used to analyze left and right weight bearing differences. Both groups had significant changes in the CSA of the MF by segment after training (p < 0.05) and the experimental group showed greater increases at the L4 (F = 9.854, p = 0.005) and L5 (F = 39. 266, p = 0.000). Both groups showed significant decreases in weight bearing, from 9.25% to 5.83% in the experimental group and from 9.33% to 4.25% in the control group (p < 0.05), but did not differ significantly between the two groups. These results suggests that stabilization exercises using ball can increases in the CSA of the MF segments, improvement in weight bearing, pain relief, and recovery from functional disorders, and the increases in the CSA of the MF of the L4 and L5 segments for patients with low back pain. Key Points Compared with the stabilization exercise using a ball and general stabilization exercise increased the CSA of the MF, weight bearing, pain, and functional ability in patients with low back pain. We verified that increases in the CSA of the MF of the L4 and L5 segments and functional ability during the stabilization exercise using a ball. The stabilization exercise using a ball was shown to be an effective exercise method for patients with low back pain in a rehabilitation program by increasing functional ability and the CSA of the MF. PMID:24149162

  10. Prevalence of risk factors for hypertension: A cross-sectional study in an urban area of Bangladesh

    PubMed Central

    Islam, Shiekh Mohammed Shariful; Mainuddin, AKM; Islam, Md Serajul; Karim, Mohammad Azizul; Mou, Sabrina Zaman; Arefin, Shamsul; Chowdhury, Kamrun Nahar

    2015-01-01

    Background: Hypertension is a major risk factor for several cardiovascular diseases (CVD). The prevalence of hypertension is increasing in Bangladesh, especially in urban areas. The objective of this study was to estimate the prevalence of hypertension and its risk factors in an urban area of Bangladesh. Methods: We conducted a cross-sectional survey involving participants aged ≥ 25 years in an urban area in Dhaka between June-December 2012, using multi-stage random sampling. Data on socioeconomic status, tobacco use, physical activity, diet, extra-salt use, family history of hypertension, CVD, anthropometric measurements and blood pressure were collected using modified WHO-STEPS protocol. Hypertension and pre-hypertension were defined according to JNC-7. Multiple logistic regressions models were used to identify risk factors associated with hypertension. Results: The overall age-adjusted prevalence hypertension and pre-hypertension among 730 participants was 23.7% and 19%, respectively, which was higher among males compared to females (23.6% vs 21.71% and 21.7% vs 17.0%, respectively). Bivariate analysis showed significant relationship of hypertension with age, BMI, no physical activity, tobacco use, extra salt intake and family history of stroke/cardiovascular disease. In the multivariate model, factors significantly associated with hypertension were older age (OR 19.18, 95% CI 13.58–28.11), smoking (OR 3.47, 95% CI 2.85–5.19), extra salt intake (OR 1.13, 95% CI 1.04–2.21), and high waist circumference (OR 3.41, 95% CI 2.81–5.29). Conclusions: The prevalence of hypertension and pre-hypertension was high among our study participants. Population-based intervention programs and policies for increased awareness about the risk factors, and life-style modification are essential for prevention of hypertension. PMID:26779518

  11. Costs of chronic obstructive pulmonary disease in urban areas of China: a cross-sectional study in four cities

    PubMed Central

    Chen, Xiaoying; Wang, Na; Chen, Yue; Xiao, Tian; Fu, Chaowei; Xu, Biao

    2016-01-01

    Purpose The economic burden of COPD has not been well studied in China. This study investigated the total costs caused by COPD and the influencing factors for the high economic burden in urban areas of China. Patients and methods A cross-sectional study was carried out among 678 COPD patients in four cities in China in 2011. The average annual direct medical costs (DMCs), direct nonmedical costs (DNMCs), and indirect costs (ICs) on COPD were measured by median and mean (± standard deviation). Logistic regression model was used to explore factors related to high total costs on COPD. Results The median annual DMCs, DNMCs, and ICs per COPD patient were RMB 5565 Yuan (US$ 862), 0 Yuan (US$ 0), and 0 Yuan (US$ 0), respectively, and the mean annual DMCs, DNMCs, and ICs per COPD patient were RMB 11968 (±22422) Yuan [US$ 1853 (±3472)], 539 (±2092) Yuan [US$ 83 (±324)], and 2087 (±8110) Yuan [US$ 323 (±1256)], respectively. The annual DMCs, DNMCs, and ICs for diagnosed COPD patients were RMB 195.70 billion Yuan (US$ 30.30 billion), 8.78 billion Yuan (US$ 1.36 billion), and 34.10 billion Yuan (US$ 5.28 billion), respectively, in China. Hospitalization accounted for 56.7% of the total costs. High economic burden was significantly related to age, acute exacerbations, and disease severity in COPD patients. Conclusion COPD posed a heavy economic burden in China. Measures to delay the disease progression and to reduce the risks of acute exacerbation and hospitalization will help substantially lower the costs for COPD care. PMID:27799761

  12. Interplay among the changes of muscle strength, cross-sectional area and maximal explosive power: theory and facts.

    PubMed

    Zamparo, P; Minetti, A E; di Prampero, P E

    2002-12-01

    A model has recently been proposed to predict the changes of mechanical power (W) during a maximal explosive effort (such as a standing high jump off both feet) following an adaptation (e.g. training/de-training). The model is based on the assumption that, all other things being equal (ceteris paribus), the predicted changes in W depend on the measured changes of muscle force (F) or cross-sectional area (CSA) only. It follows that, if the measured changes in W are not equal to those predicted by the model, factors other than a change in F (or CSA) must be responsible for this difference. The model does not allow the determination of factors specifically involved in the adaptation process but it helps in discriminating whether an adaptation has taken place at a local level (when the observed changes in F would be attributed to factors other than the observed changes in CSA, e.g. co-contractions, fibre type modifications...), or at a central level (when the observed changes in W would be attributed to other factors than the observed changes in F, e.g. co-ordination of multiple joints and muscle groups...), or in both regions. In this paper the model has been applied to data reported in the literature on disuse (BR, bed rest), de-conditioning (SF, space flight), strength training (ST) and de-training (DT). The results of these calculations have confirmed previous observations on the determinants of the adaptation process and further suggest: (1) that training for one specific motor task (e.g. ST) could affect the performance of a second task (e.g. a maximal explosive jump) but that, as soon as the trained motor task is terminated (DT), this ability is re-gained; and (2) that neuromuscular impairment in disuse (BR) is closer to de-training than to the de-conditioning brought about by weightlessness (SF). PMID:12458362

  13. Status of cardiovascular health among adults in a rural area of Northwest China: Results from a cross-sectional study.

    PubMed

    Zhao, Yaling; Yan, Hong; Yang, Ruihai; Li, Qiang; Dang, Shaonong; Liu, Ruru; Pei, Leilei; Cao, Lei; Marshall, Roger J; Wang, Duolao

    2016-07-01

    The aim of this study was to assess the status of cardiovascular health among a rural population in Northwest China and to determine the associated factors for cardiovascular health.A population-based cross-sectional study was conducted in the rural areas of Hanzhong in Northwest China. Interview, physical examination, and fasting blood glucose and lipid measurements were completed for 2693 adults. The construct of cardiovascular health and the definitions of cardiovascular health metrics proposed by the American Heart Association were used to assess cardiovascular health. The proportions of subjects with cardiovascular health metrics were calculated, adjusting for age and sex. The multiple logistic regression model was used to evaluate the association between ideal cardiovascular health and its associated factors.Only 0.5% (0.0% in men vs 0.9% in women, P = 0.002) of the participants had ideal cardiovascular health, whereas 33.8% (18.0% in men vs 50.0% in women, P < 0.001) and 65.7% (82.0% in men vs 49.1% in women, P < 0.001) of the participants had intermediate and poor cardiovascular health, respectively. The prevalence of poor cardiovascular health increased with increasing age (P < 0.001 for trend). Participants fulfilled, on average, 4.4 (95% confidence interval: 4.2-4.7) of the ideal cardiovascular health metrics. Also, 22.2% of the participants presented with 3 or fewer ideal metrics. Only 19.4% of the participants presented with 6 or more ideal metrics. 24.1% of the participants had all 4 ideal health factors, but only 1.1% of the participants had all 4 ideal health behaviors. Women were more likely to have ideal cardiovascular health, whereas adults aged 35 years or over and those who had a family history of hypertension were less likely to have ideal cardiovascular health.The prevalence of ideal cardiovascular health was extremely low among the rural population in Northwest China. Most adults, especially men and the elderly, had a poor

  14. Feeding Patterns and Predictors of Malnutrition in Infants from Poor Socioeconomic Areas in Pakistan: A Cross-sectional Survey

    PubMed Central

    Anwar ul Haq, Malik Muhammad; Tariq, Saad; Anwar, Madiha; Khawar, Anam; Waqas, Ahmed; Nisar, Anam

    2016-01-01

    Introduction: Malnutrition, a state of under or over nutrition caused by improper food intake, causes significant morbidity and mortality in developing countries. It leads to a number of diseases which can be further divided into those caused by protein-caloric malnutrition and those caused by vitamin deficiencies, micronutrient, and mineral deficiencies. The purpose of this study was to identify the factors which contribute to malnutrition and to assess the dietary pattern in the pediatric population from birth up to five months belonging to poor socioeconomic areas. The children in this sample presented to a tertiary care hospital in the district of Sargodha, Pakistan. The findings in this cohort will support the development of an effective plan to tackle these issues. Methods: This cross-sectional study was undertaken between June 2014 and December 2014 at the inpatient pediatric department of District Headquarter Hospital Sargodha. Data were collected and recorded on a predesigned form which consisted of four sections to record 1) demographics: parents' level of education, monthly income, number of dependent household members, and birth interval; 2) anthropometric and personal history, birth history, and degree of malnutrition; 3) any secondary causes of malnutrition; and 4) feeding history. The data were analyzed in SPSS v. 20. Chi-squared, phi statistics, and logistic regression analysis were run to analyze the data. Results: A total of 294 participants were included in the study. Logistic regression analysis showed that the degree of malnutrition was associated negatively with increasing age and positively with family size. A majority of children (144, 49%) were being breastfed for less than 5 minutes followed by 38 (13%) > 5 minutes to 15 minutes, and 2 (0.7%) > 15 minutes while 110 (37 %) infants were not breastfed. Children who were breastfed were less likely to have severe malnutrition than those who were given formula, fresh cow's or goat's milk

  15. Cross-Sectional Area of the Rotator Cuff Muscles in MRI – Is there Evidence for a Biomechanical Balanced Shoulder?

    PubMed Central

    Bouaicha, Samy; Slankamenac, Ksenija; Moor, Beat K.; Tok, Sina; Andreisek, Gustav; Finkenstaedt, Tim

    2016-01-01

    Objective To provide in-vivo evidence for the common biomechanical concept of transverse and craniocaudal force couples in the shoulder that are yielded by both the rotator cuff muscles (RCM) and the deltoid and to quantitatively evaluate and correlate the cross-sectional areas (CSA) of the corresponding RCM as a surrogate marker for muscle strength using MRI. Materials and Methods Fifty patients (mean age, 36 years; age range, 18–57 years; 41 male, 9 female) without rotator cuff tears were included in this retrospective study. Data were assessed by two readers. The CSA (mm2) of all rotator cuff muscles was measured on parasagittal T1-weighted FSE sequence at two different positions (at the established “y-position” and at a more medial slice in the presumably maximal CSA for each muscle, i.e., the “set position”). The CSA of the deltoid was measured on axial intermediate-weighted FSE sequences at three positions. CSA measurements were obtained using 1.5 Tesla MR-arthrographic shoulder. Pearson’s correlation for the corresponding CSA of the force couple as well as was the intraclass correlation coefficient for the inter- and intra-reader agreement was calculated. Results The mean CSA was 770 mm2 (±167) and 841 mm2 (±191) for the supraspinatus (in the y- and set-positions, respectively) and 984 mm2 (±241) and 1568 mm2 (±338) for the infraspinatus. The mean CSA was 446 mm2 (±129) and 438 mm2 (±128) for the teres minor (in the y- and set-positions, respectively) and 1953 mm2 (±553) and 2343 mm2 (±587) for the subscapularis. The three measurements of the deltoid revealed a CSA of 3063 mm2 (±839) for the upper edge, 3829 mm2 (±836) for the lower edge and 4069 mm2 (±937) for the middle of the glenoid. At the set position Pearson’s correlation of the transverse force couple (subscapularis/infraspinatus) showed a moderate positive correlation of r = 0.583 (p<0.0001) and a strong correlation when the CSA of the teres minor was added to the

  16. Does the ratio of the carpal tunnel inlet and outlet cross-sectional areas in the median nerve reflect carpal tunnel syndrome severity?

    PubMed

    Zhang, Li; Rehemutula, Aierken; Peng, Feng; Yu, Cong; Wang, Tian-Bin; Chen, Lin

    2015-07-01

    Although ultrasound measurements have been used in previous studies on carpal tunnel syndrome to visualize injury to the median nerve, whether such ultrasound data can indicate the severity of carpal tunnel syndrome remains controversial. The cross-sectional areas of the median nerve at the tunnel inlet and outlet can show swelling and compression of the nerve at the carpal. We hypothesized that the ratio of the cross-sectional areas of the median nerve at the carpal tunnel inlet to outlet accurately reflects the severity of carpal tunnel syndrome. To test this, high-resolution ultrasound with a linear array transducer at 5-17 MHz was used to assess 77 patients with carpal tunnel syndrome. The results showed that the cut-off point for the inlet-to-outlet ratio was 1.14. Significant differences in the inlet-to-outlet ratio were found among patients with mild, moderate, and severe carpal tunnel syndrome. The cut-off point in the ratio of cross-sectional areas of the median nerve was 1.29 between mild and more severe (moderate and severe) carpal tunnel syndrome patients with 64.7% sensitivity and 72.7% specificity. The cut-off point in the ratio of cross-sectional areas of the median nerve was 1.52 between the moderate and severe carpal tunnel syndrome patients with 80.0% sensitivity and 64.7% specificity. These results suggest that the inlet-to-outlet ratio reflected the severity of carpal tunnel syndrome.

  17. Bacterial infection, airway and systemic inflammation and clinical outcomes before and after treatment of AECOPD, a longitudinal and cross-sectional study.

    PubMed

    Chang, Chun; Zhu, Hong; Shen, Ning; Chen, Yahong; He, Bei; Zhao, Jiangchao; Yao, Wanzhen

    2015-02-01

    Abstract Bacterial infection is a major cause of acute exacerbations of chronic obstructive pulmonary disease (AECOPD), which are associated with significantly increased airway and systemic inflammation. However, the relationship among bacteriology, the resolution of inflammation and clinical outcomes is largely unknown. In this study, we recruited consecutive patients hospitalized for AECOPD with purulent sputum. We measured the airway and systemic inflammation levels, the COPD assessment test (CAT) score and adverse outcomes between patients with and without potentially pathogenic microorganisms (PPM). Among sputum samples collected from the 135 episodes of AECOPD, 42 (31.1%) were PPM-positive at admission. Compared with those in the PPM-negative group, more patients in the PPM-positive group had ≥2 exacerbations in previous year and Anthonisen type I at admission and higher drop in sputum neutrophil, serum hs-CRP and CAT value from exacerbation to the subsequent baseline. No significant differences in the adverse outcomes between the two groups were observed. Among the 38 PPM-positive patients who survived and were discharged from hospital, 19 remained PPM-positive (bacterial persistence group) and 19 PPM-negative (bacterial clearance group). Both inflammation indices and CAT score decreased compared to admission in the two groups, regardless of the bacteriology at discharge. Our data suggest uncultivated bacteria and/or virus might also play important roles in causing inflammation and AECOPD.

  18. Bacterial infection, airway and systemic inflammation and clinical outcomes before and after treatment of AECOPD, a longitudinal and cross-sectional study.

    PubMed

    Chang, Chun; Zhu, Hong; Shen, Ning; Chen, Yahong; He, Bei; Zhao, Jiangchao; Yao, Wanzhen

    2015-02-01

    Abstract Bacterial infection is a major cause of acute exacerbations of chronic obstructive pulmonary disease (AECOPD), which are associated with significantly increased airway and systemic inflammation. However, the relationship among bacteriology, the resolution of inflammation and clinical outcomes is largely unknown. In this study, we recruited consecutive patients hospitalized for AECOPD with purulent sputum. We measured the airway and systemic inflammation levels, the COPD assessment test (CAT) score and adverse outcomes between patients with and without potentially pathogenic microorganisms (PPM). Among sputum samples collected from the 135 episodes of AECOPD, 42 (31.1%) were PPM-positive at admission. Compared with those in the PPM-negative group, more patients in the PPM-positive group had ≥2 exacerbations in previous year and Anthonisen type I at admission and higher drop in sputum neutrophil, serum hs-CRP and CAT value from exacerbation to the subsequent baseline. No significant differences in the adverse outcomes between the two groups were observed. Among the 38 PPM-positive patients who survived and were discharged from hospital, 19 remained PPM-positive (bacterial persistence group) and 19 PPM-negative (bacterial clearance group). Both inflammation indices and CAT score decreased compared to admission in the two groups, regardless of the bacteriology at discharge. Our data suggest uncultivated bacteria and/or virus might also play important roles in causing inflammation and AECOPD. PMID:24800883

  19. The skeletal muscle cross sectional area in long-term bisphosphonate users is smaller than that of bone mineral density-matched controls with increased serum pentosidine concentrations.

    PubMed

    Uchiyama, Shigeharu; Ikegami, Shota; Kamimura, Mikio; Mukaiyama, Keijiro; Nakamura, Yukio; Nonaka, Kiichi; Kato, Hiroyuki

    2015-06-01

    Bisphosphonates are effective in increasing bone mineral density (BMD), but fragility fractures can still occur despite bisphosphonate treatment. The purpose of this study was to determine if long-term bisphosphonate users have characteristic findings in the musculoskeletal system, which could put them at risk of developing typical or atypical femoral fractures. We recruited 40 female patients who had taken bisphosphonates for more than 3 years. The control group included 60 volunteers who were matched by age, body mass index, and dual-energy X-ray absorptiometry-derived BMDs. We measured the skeletal muscle cross sectional area around the proximal thigh and buckling ratio of the femoral neck using quantitative computed tomography (qCT) and several biochemical markers of bone metabolism. Those parameters were compared between the groups. While no significant differences of buckling ratio derived from qCT were detected, the skeletal muscle cross sectional area was significantly smaller in the long-term bisphosphonate users than in the controls. Furthermore, the serum pentosidine level was significantly higher in the bisphosphonate users than in the controls. To determine if those differences were attributable to bisphosphonate treatment, we further compared those parameters between before and after 3 years of bisphosphonate treatment in 32 patients. After 3 years of bisphosphonate treatment, the BMD of the femoral neck and serum pentosidine level increased but not the skeletal muscle cross sectional area. In the present study, the skeletal muscle mass did not match the bone mass in long-term bisphosphonate users, thus suggesting that increases in BMD by bisphosphonates are unlikely to have secondary positive effects on the surrounding skeletal muscles. Also, serum pentosidine levels were greater in the long-term bisphosphonate users. Further study is necessary to test if such patients are prone to develop typical or atypical femoral fractures. PMID:25708052

  20. Effects of long-term low-level radiation exposure after the Chernobyl catastrophe on immunoglobulins in children residing in contaminated areas: prospective and cross-sectional studies

    PubMed Central

    2014-01-01

    Background After the Chernobyl nuclear incident in 1986, children in the Narodichesky region, located 80 km west of the Chernobyl Power Plant, were exposed to 137Cesium (137Cs). Little is known about the effects of chronic low-level radiation on humoral immune responses in children residing in contaminated areas. Methods In four different approaches we investigated the effect of residential 137Cs exposure on immunoglobulins A, G, M, and specific immunoglobulin E in children. In a dynamic cohort (1993–1998) we included 617 children providing 2,407 repeated measurements; 421 and 523 children in two cross-sectional samples (1997–1998 and 2008–2010, respectively); and 25 participants in a small longitudinal cohort (1997–2010). All medical exams, blood collections, and analyses were conducted by the same team. We used mixed linear models to analyze repeated measurements in cohorts and general linear regression models for cross-sectional studies. Results Residential soil contamination in 2008 was highly correlated with the individual body burden of 137Cs. Serum IgG and IgM concentrations increased between 1993 and 1998. Children with higher 137Cs soil exposure had lower serum IgG levels, which, however, increased in the small cohort assessed between 1997 and 2010. Children within the fourth quintile of 137Cs soil exposure (266–310 kBq/m2) had higher IgM serum concentrations between 1993 and 1998 but these declined between 1997 and 2010. IgA remained stable with median 137Cs exposures related to higher IgA levels, which was corroborated in the cross-sectional study of 2008–2010. Specific IgE against indoor allergens was detected less often in children with higher 137Cs exposure. Conclusions Our findings show radiation-related alterations of immunoglobulins which by themselves do not constitute adverse health effects. Further investigations are necessary to understand how these changes affect health status. PMID:24886042

  1. A Cross-Sectional Survey to Estimate the Cat Population and Ownership Profiles in a Semirural Area of Central Italy

    PubMed Central

    Iacoponi, Francesca; Scaramozzino, Paola

    2016-01-01

    Understanding animal population size and its demographic features is essential to address Public Health policies as well as to provide valuable information to pet industries and veterinary practitioners. Nevertheless, official data on feline population are not available worldwide. In the present study, the owned cat population size, its demographic attributes, and the ownership profiles have been investigated through a face-to-face questionnaire in a semirural area of Central Italy. The human : cat ratio was equal to 6.8 (95% CI: 5.7–7.5); 29.3% of households own at least one cat. The majority of cats were living in a rural area (67.8%) and outdoors, were neutered (70.5%), and were fed with commercial food (54.8%) and they visited a veterinarian 1-2 times a year (43.3%). The cat ownership was strongly associated with people living in a rural area and owning another pet. As the cat owned population was mainly kept outdoors in rural areas, the possible relation between the owned and the stray animals is worthy to be monitored in future researches. Our study revealed that the feline owned population was larger than expected and that social and economic human factors do not influence the cat ownership. Health Authorities and veterinary practitioners should promote responsible ownership to increase the veterinary care, to intensify the official identification, and to properly manage the outdoor lifestyle.

  2. A Cross-Sectional Survey to Estimate the Cat Population and Ownership Profiles in a Semirural Area of Central Italy

    PubMed Central

    Iacoponi, Francesca; Scaramozzino, Paola

    2016-01-01

    Understanding animal population size and its demographic features is essential to address Public Health policies as well as to provide valuable information to pet industries and veterinary practitioners. Nevertheless, official data on feline population are not available worldwide. In the present study, the owned cat population size, its demographic attributes, and the ownership profiles have been investigated through a face-to-face questionnaire in a semirural area of Central Italy. The human : cat ratio was equal to 6.8 (95% CI: 5.7–7.5); 29.3% of households own at least one cat. The majority of cats were living in a rural area (67.8%) and outdoors, were neutered (70.5%), and were fed with commercial food (54.8%) and they visited a veterinarian 1-2 times a year (43.3%). The cat ownership was strongly associated with people living in a rural area and owning another pet. As the cat owned population was mainly kept outdoors in rural areas, the possible relation between the owned and the stray animals is worthy to be monitored in future researches. Our study revealed that the feline owned population was larger than expected and that social and economic human factors do not influence the cat ownership. Health Authorities and veterinary practitioners should promote responsible ownership to increase the veterinary care, to intensify the official identification, and to properly manage the outdoor lifestyle. PMID:27610373

  3. A Cross-Sectional Survey to Estimate the Cat Population and Ownership Profiles in a Semirural Area of Central Italy.

    PubMed

    Carvelli, Andrea; Iacoponi, Francesca; Scaramozzino, Paola

    2016-01-01

    Understanding animal population size and its demographic features is essential to address Public Health policies as well as to provide valuable information to pet industries and veterinary practitioners. Nevertheless, official data on feline population are not available worldwide. In the present study, the owned cat population size, its demographic attributes, and the ownership profiles have been investigated through a face-to-face questionnaire in a semirural area of Central Italy. The human : cat ratio was equal to 6.8 (95% CI: 5.7-7.5); 29.3% of households own at least one cat. The majority of cats were living in a rural area (67.8%) and outdoors, were neutered (70.5%), and were fed with commercial food (54.8%) and they visited a veterinarian 1-2 times a year (43.3%). The cat ownership was strongly associated with people living in a rural area and owning another pet. As the cat owned population was mainly kept outdoors in rural areas, the possible relation between the owned and the stray animals is worthy to be monitored in future researches. Our study revealed that the feline owned population was larger than expected and that social and economic human factors do not influence the cat ownership. Health Authorities and veterinary practitioners should promote responsible ownership to increase the veterinary care, to intensify the official identification, and to properly manage the outdoor lifestyle. PMID:27610373

  4. A Cross-Sectional Survey to Estimate the Cat Population and Ownership Profiles in a Semirural Area of Central Italy.

    PubMed

    Carvelli, Andrea; Iacoponi, Francesca; Scaramozzino, Paola

    2016-01-01

    Understanding animal population size and its demographic features is essential to address Public Health policies as well as to provide valuable information to pet industries and veterinary practitioners. Nevertheless, official data on feline population are not available worldwide. In the present study, the owned cat population size, its demographic attributes, and the ownership profiles have been investigated through a face-to-face questionnaire in a semirural area of Central Italy. The human : cat ratio was equal to 6.8 (95% CI: 5.7-7.5); 29.3% of households own at least one cat. The majority of cats were living in a rural area (67.8%) and outdoors, were neutered (70.5%), and were fed with commercial food (54.8%) and they visited a veterinarian 1-2 times a year (43.3%). The cat ownership was strongly associated with people living in a rural area and owning another pet. As the cat owned population was mainly kept outdoors in rural areas, the possible relation between the owned and the stray animals is worthy to be monitored in future researches. Our study revealed that the feline owned population was larger than expected and that social and economic human factors do not influence the cat ownership. Health Authorities and veterinary practitioners should promote responsible ownership to increase the veterinary care, to intensify the official identification, and to properly manage the outdoor lifestyle.

  5. The effects of magnetic-field geometry on longitudinal oscillations of solar prominences: Cross-sectional area variation for thin tubes

    NASA Astrophysics Data System (ADS)

    Luna, M.; Díaz, A. J.; Oliver, R.; Terradas, J.; Karpen, J.

    2016-09-01

    Context. Solar prominences are subject to both field-aligned (longitudinal) and transverse oscillatory motions, as evidenced by an increasing number of observations. Large-amplitude longitudinal motions provide valuable information on the geometry of the filament-channel magnetic structure that supports the cool prominence plasma against gravity. Our pendulum model, in which the restoring force is the gravity projected along the dipped field lines of the magnetic structure, best explains these oscillations. However, several factors can influence the longitudinal oscillations, potentially invalidating the pendulum model. Aims: The aim of this work is to study the influence of large-scale variations in the magnetic field strength along the field lines, i.e., variations of the cross-sectional area along the flux tubes supporting prominence threads. Methods: We studied the normal modes of several flux tube configurations, using linear perturbation analysis, to assess the influence of different geometrical parameters on the oscillation properties. Results: We found that the influence of the symmetric and asymmetric expansion factors on longitudinal oscillations is small. Conclusions: We conclude that the longitudinal oscillations are not significantly influenced by variations of the cross-section of the flux tubes, validating the pendulum model in this context.

  6. Overweight according to geographical origin and time spent in France: a cross sectional study in the Paris metropolitan area

    PubMed Central

    2012-01-01

    Background For the first time in France in a population-based survey, this study sought to investigate the potential impact of migration origin and the proportion of lifetime spent in mainland France on body mass index (BMI) and overweight in adults living in the Paris metropolitan area. Methods A representative, population-based, random sample of the adult, French speaking population of the Paris metropolitan area was interviewed in 2005. Self-reported BMI (BMI = weight/height2) and overweight (BMI ≥ 25) were our 2 outcomes of interest. Two variables were constructed to estimate individuals’ migration origin: parental nationality and the proportion of lifetime spent in mainland France, as declared by the participants. We performed multilevel regression models among different gender and age groups, adjusted for demographics and socioeconomic status. Results In women, a parental origin in the Middle East or North Africa (MENA) was associated with a higher risk of being overweight (especially before the age of 55) and a higher BMI (between 35 and 54 years of age), and so were women of Sub-Sahara African parental origin in the middle age category. Only in the youngest men (< 35 years of age) did we observe any association with parental nationality, with a higher BMI when having a MENA parentage. Regarding the association between the proportion of lifetime spent in France and overweight, we observed that, in women, a proportion of 50% to 99% appeared to be associated with overweight, especially after the age of 35. In men, having spent more than half of one’s lifetime in France was associated with a higher risk of overweight among oldest men. Conclusions Our results plea for potential cultural determinants of overweight in the migrant and migrants-born populations in the French context of the capital region. Taking into account the people’ family and personal migration histories may be an important issue in public health research and policies on overweight and

  7. Social Ties May Play a Critical Role in Mitigating Sleep Difficulties in Disaster-Affected Communities: A Cross-Sectional Study in the Ishinomaki Area, Japan

    PubMed Central

    Matsumoto, Shoko; Yamaoka, Kazue; Inoue, Machiko; Muto, Shinsuke

    2014-01-01

    Study Objectives: We examined the association between social factors and sleep difficulties among the victims remaining at home in the Ishinomaki area after the Great East Japan Earthquake and Tsunami and identified potentially modifiable factors that may mitigate vulnerability to sleep difficulties during future traumatic events or disasters. Design: A cross-sectional household survey was conducted from October 2011 to March 2012 (6-12 mo after the disaster) in the Ishinomaki area, Japan. Univariate and multivariate logistic regression models were used to examine associations between social factors and sleep difficulties. Participants: We obtained data on 4,176 household members who remained in their homes after the earthquake and tsunami. Interventions: N/A. Results: Sleep difficulties were prevalent in 15.0% of the respondents (9.2% male, 20.2% female). Two potentially modifiable factors (lack of pleasure in life and lack of interaction with/visiting neighbors) and three nonmodifiable or hardly modifiable factors (sex, source of income, and number of household members) were associated with sleep difficulties. Nonmodifiable or hardly modifiable consequences caused directly by the disaster (severity of house damage, change in family structure, and change in working status) were not significantly associated with sleep difficulties. Conclusions: Our data suggest that the lack of pleasure in life and relatively strong networks in the neighborhood, which are potentially modifiable, might have stronger associations with sleep difficulties than do nonmodifiable or hardly modifiable consequences of the disaster (e.g., house damage, change in family structure, and change in work status). Citation: Matsumoto S; Yamaoka K; Inoue M; Muto S. Social ties may play a critical role in mitigating sleep difficulties in disaster-affected communities: a cross-sectional study in the Ishinomaki area, Japan. SLEEP 2014;37(1):137-145. PMID:24470703

  8. Stratigraphic cross section of measured sections and drill holes of the Neslan Formation and adjacent formations, Book Cliffs Area, Colorado and Utah

    USGS Publications Warehouse

    Kirshbaum, Mark A.; Spear, Brianne D.

    2012-01-01

    This study updates a stratigraphic cross section published as plate 2 in Kirschbaum and Hettinger (2004) Digital Data Series 69-G (http://pubs.usgs.gov/dds/dds-069/dds-069-g/). The datum is a marine/tidal ravinement surface within the Cozzette Sandstone Member of the Iles Formation and the Thompson Canyon Sandstone and Sulphur Canyon Sandstone Beds of the Neslen Formation. One of the cores shown was included on the original cross section, and new core descriptions have been added to the upper part of the cored interval. A new core description (S178) is included in this report. Cores are stored in the U.S. Geological Survey Core Research Facility at the Denver Federal Center, Colorado. The following information has also been added to help define the stratigraphic framework: 1) At least five claystones interpreted as altered volcanic ashes have been identified and may give future workers a correlation tool within the largely continental section. 2) Thickness and general geometry of the Sego Sandstone, Buck Tongue of the Mancos Shale, and Castlegate Sandstone have been added to provide additional stratigraphic context. 3) The geometry in the Sego Sandstone, Buck Tongue of the Mancos Shale, and Castlegate Sandstone has been added to provide additional stratigraphic context. 4) Ammonite collections are from Gill and Hail. The zone of Didymoceras nebrascense projected into the East Salt Wash area is based on correlation of the flooding surface at the base of the Cozzette Member to this point as shown in Kirschbaum and Hettinger. 5) A leaf locality of the Denver Museum of Nature and Science is shown in its approximate stratigraphic position near Thompson Canyon. 6) A dinosaur locality of the Natural History Museum of Utah is shown in the Horse Canyon area measured section at the stratigraphic position where it was extracted.

  9. Exploring Subduction, Slab Breakoff, and Upper-Plate Deformation in the Georgian Greater Caucasus: Shortening Estimates from Area- and Line-Balanced Crustal Scale Cross Sections

    NASA Astrophysics Data System (ADS)

    Trexler, C. C.; Cowgill, E.; Niemi, N. A.; Godoladze, T.

    2015-12-01

    observations. These sections contain ~230 km of total shortening. Based on area-balanced cross sections along the same transects, this magnitude of shortening falls within the expected range of the subduction/ slab breakoff model, and is greater than might be expected from either buoyancy driven uplift or closure of a small basin.

  10. The Variation in the Lumbar Facet Joint Orientation in an Adult Asian Population and Its Relationship with the Cross-Sectional Area of the Multifidus and Erector Spinae

    PubMed Central

    Katayose, Masaki; Watanabe, Kota

    2016-01-01

    Study Design Cross-sectional study of healthy volunteers. Purpose We aimed to investigate the variation in the lumbar facet joint orientation in an adult Asian population. The relationship between the facet joint orientation and muscle cross-sectional area (CSA) of multifidus and erector spinae was also clarified. Overview of Literature Several studies have reported that lumbar pathologies, such as lumbar spondylolysis and degenerative spondylolisthesis, were related to the horizontally shaped lumbar facet joint orientation at the lower lumbar level. However, data regarding variations in the facet joint orientation in asymptomatic subjects have not been well documented. Methods In 31 healthy male adult Asian volunteers, the facet joint orientation and CSA of multifidus and erector spinae were measured using magnetic resonance imaging at the L4–5 and L5–S1 levels. Variation in the facet joint orientation was examined using coefficients of variation (CV). Pearson's product-moment coefficient was used to investigate the relationship between the facet joint orientation and CSA of multifidus and erector spinae. Results Lumbar facet joint orientation had a wider range of variation at L5–S1 (CV=0.30) than at L4–5 (CV=0.18). The L4–5 facet joint orientation had a weak but significant correlation with the CSA of erector spinae (r=0.40; p=0.031). The CSA of the multifidus had no relationship with the facet joint orientation at the L4–5 (r=0.19; p=0.314) and the L5–S1 level (r=0.19; p=0.312). Conclusions The lumbar facet joint orientation was found to have a wide variation, particularly at the L5–S1 in the Asian adult population, and the facet joint orientation had a relationship with the CSA of the erector spinae at the L4–5. PMID:27790316

  11. Morbidity Among Tribal Under-Five Children of Tea Garden Areas in a Block of Darjeeling District, West Bengal: A Cross-Sectional Study

    PubMed Central

    Ishore, Kaushik; Das, Dilip Kumar

    2015-01-01

    Background In the developing world, more than half of infant and childhood mortality is related to childhood diseases particularly- acute respiratory infections (ARI) and diarrhoea. The situation is worse among underprivileged population such as tribals and people living in tea garden areas. Aim To identify the morbidity pattern and the associated factors among tribal, under five, children living in tea garden areas of Darjeeling district. Materials and Methods A cross-sectional study was conducted in three randomly chosen tea garden areas of a block in Darjeeling District, West Bengal, India from September 2013-February 2014. The collected data was analysed using SPSS software and binary logistic regression was applied to test association between morbidity and other epidemiological correlates. Results Morbidity was noted among 74 out of 192 children studied. Major causes of morbidity were- diarrhoea (26%), acute respiratory infections (24.5%) and fever (16.7%). Proportion of underweight children according to their age was 64.4%. Morbidity status was found statistically significant with some factors, like- religion, socio-economic status, immunization status and number of siblings. Conclusion There is high prevalence of diarrhoea and ARI associated morbidity in this part of the country. PMID:26468469

  12. Mid-femoral and mid-tibial muscle cross-sectional area as predictors of tibial bone strength in middle-aged and older men.

    PubMed

    Rantalainen, T; Nikander, R; Kukuljan, S; Daly, R M

    2013-09-01

    While it is widely acknowledged that bones adapt to the site-specific prevalent loading environment, reasonable ways to estimate skeletal loads are not necessarily available. For long bone shafts, muscles acting to bend the bone may provide a more appropriate surrogate of the loading than muscles expected to cause compressive loads. Thus, the aim of this study was to investigate whether mid-thigh muscle cross-sectional area (CSA) was a better predictor of tibial mid-shaft bone strength than mid-tibia muscle CSA in middle aged and older men. 181 Caucasian men aged 50-79 years (mean±SD; 61±7 years) participated in this study. Mid-femoral and mid-tibial bone traits cortical area, density weighted polar moment of area and muscle CSA [cm(2)] were assessed with computed tomography. Tibial bone traits were positively associated with both the mid-femur (r=0.44 to 0.46, P<0.001) and the mid-tibia muscle CSA (r=0.35 to 0.37, P<0.001). Multivariate regression analysis, adjusting for age, weight, physical activity and femoral length, indicated that mid-femur muscle CSA predicted tibial mid-shaft bone strength indices better than mid-tibia muscle CSA. In conclusion, the association between a given skeletal site and functionally adjacent muscles may provide a meaningful probe of the site-specific effect of loading on bone. PMID:23989248

  13. Radar cross section of insects

    NASA Astrophysics Data System (ADS)

    Riley, J. R.

    1985-02-01

    X-band measurements of radar cross section as a function of the angle between insect body axis and the plane of polarization are presented. A finding of particular interest is that in larger insects, maximum cross section occurs when the E-vector is perpendicular to the body axis. A new range of measurements on small insects (aphids, and planthoppers) is also described, and a comprehensive summary of insect cross-section data at X-band is given.

  14. SU-C-207-07: Quantification of Coronary Artery Cross-Sectional Area in CT Angiography Using Integrated Density: A Phantom Study

    SciTech Connect

    Johnson, T; Ding, H; Torabzadeh, M; Molloi, S

    2015-06-15

    Purpose: To investigate the feasibility of quantifying the cross-sectional area (CSA) of coronary arteries using integrated density in a physics-based model with a phantom study. Methods: In this technique the total integrated density of the object as compared with its local background is measured so it is possible to account for the partial volume effect. The proposed method was compared to manual segmentation using CT scans of a 10 cm diameter Lucite cylinder placed inside a chest phantom. Holes with cross-sectional areas from 1.4 to 12.3 mm{sup 2} were drilled into the Lucite and filled with iodine solution, producing a contrast-to-noise ratio of approximately 26. Lucite rods 1.6 mm in diameter were used to simulate plaques. The phantom was imaged with and without the Lucite rods placed in the holes to simulate diseased and normal arteries, respectively. Linear regression analysis was used, and the root-mean-square deviations (RMSD) and errors (RMSE) were computed to assess the precision and accuracy of the measurements. In the case of manual segmentation, two readers independently delineated the lumen in order to quantify the inter-reader variability. Results: The precision and accuracy for the normal vessels using the integrated density technique were 0.32 mm{sup 2} and 0.32 mm{sup 2}, respectively. The corresponding results for the manual segmentation were 0.51 mm{sup 2} and 0.56 mm{sup 2}. In the case of diseased vessels, the precision and accuracy of the integrated density technique were 0.46 mm{sup 2} and 0.55 mm{sup 2}, respectively. The corresponding results for the manual segmentation were 0.75 mm{sup 2} and 0.98 mm{sup 2}. The mean percent difference for the two readers was found to be 8.4%. Conclusion: The CSA based on integrated density had improved precision and accuracy as compared with manual segmentation in a Lucite phantom. The results indicate the potential for using integrated density to improve CSA measurements in CT angiography.

  15. Considering sampling strategy and cross-section complexity for estimating the uncertainty of discharge measurements using the velocity-area method

    NASA Astrophysics Data System (ADS)

    Despax, Aurélien; Perret, Christian; Garçon, Rémy; Hauet, Alexandre; Belleville, Arnaud; Le Coz, Jérôme; Favre, Anne-Catherine

    2016-02-01

    Streamflow time series provide baseline data for many hydrological investigations. Errors in the data mainly occur through uncertainty in gauging (measurement uncertainty) and uncertainty in the determination of the stage-discharge relationship based on gaugings (rating curve uncertainty). As the velocity-area method is the measurement technique typically used for gaugings, it is fundamental to estimate its level of uncertainty. Different methods are available in the literature (ISO 748, Q + , IVE), all with their own limitations and drawbacks. Among the terms forming the combined relative uncertainty in measured discharge, the uncertainty component relating to the limited number of verticals often includes a large part of the relative uncertainty. It should therefore be estimated carefully. In ISO 748 standard, proposed values of this uncertainty component only depend on the number of verticals without considering their distribution with respect to the depth and velocity cross-sectional profiles. The Q + method is sensitive to a user-defined parameter while it is questionable whether the IVE method is applicable to stream-gaugings performed with a limited number of verticals. To address the limitations of existing methods, this paper presents a new methodology, called FLow Analog UnceRtainty Estimation (FLAURE), to estimate the uncertainty component relating to the limited number of verticals. High-resolution reference gaugings (with 31 and more verticals) are used to assess the uncertainty component through a statistical analysis. Instead of subsampling purely randomly the verticals of these reference stream-gaugings, a subsampling method is developed in a way that mimicks the behavior of a hydrometric technician. A sampling quality index (SQI) is suggested and appears to be a more explanatory variable than the number of verticals. This index takes into account the spacing between verticals and the variation of unit flow between two verticals. To compute the

  16. Association of urinary monomethylated arsenic concentration and risk of hypertension: a cross-sectional study from arsenic contaminated areas in northwestern China

    PubMed Central

    2013-01-01

    Background Although some studies mainly from Taiwan, Bangladesh and the United States, have suggested a consistent dose–response increase in the prevalence of hypertension with increasing arsenic exposure, the association between chronic environmental arsenic exposure and the risk of hypertension is still inconclusive. Most of the studies discussed the association from the point of view of arsenic concentration in drinking water or cumulative arsenic exposure (CAE), few involved arsenic speciation into the discussion. In this cross-sectional study, we evaluated the potential association between environmental arsenic exposure through drinking water and the prevalence of hypertension by analyzing not only CAE but also urinary arsenic speciation, and provided data on arsenic exposure and hypertension from mainland of China. Methods A cross-sectional study was conducted in one of the arsenic contaminated areas in the northwest of China. Among a total of 1005 residents who voluntarily participated in the study, 604 of eligible subjects were confirmed and interviewed door to door. Standing height, body weight, and blood pressure were measured. First void urine was collected and measured for the concentration of urinary arsenic speciation. CAE was calculated in a subpopulation of 360 subjects with detailed water consumption history. The association between urinary arsenic speciation, CAE and the risk of hypertension were analyzed by multiple logistic regressions. Results We found that the levels of urinary arsenic species of inorganic arsenic (iAs), monomethylated arsenic (MMA), dimethylated arsenic (DMA) and total arsenic (tAs) were significantly correlated with systolic or pulse blood pressure. A positive relationship was found between the highest tertile of CAE and hypertension in a dose-dependent manner. Subjects with higher concentration of urinary MMA or lower percentage of DMA tended to be liable to suffer from hypertension. A significant increasing trend of the

  17. The cross-sectional relationship between dietary calcium intake and metabolic syndrome among men and women aged 40 or older in rural areas of Korea

    PubMed Central

    Shin, Song Kyoung; Lee, Young-Hoon; Shin, Dong Hoon; Shin, Min-Ho; Chun, Byung-Yeol; Choi, Bo Youl

    2015-01-01

    BACKGROUND/OBJECTIVES Studies conducted in Western populations have suggested that dietary calcium may protect against metabolic abnormalities, but there is little evidence of this effect in Asians, who have relatively low calcium intake. We evaluated the cross-sectional relationship between dietary calcium and metabolic syndrome among Korean men and women aged 40 years and over. SUBJECTS/METHODS A total of 6,375 subjects aged 40 years and over and were recruited between January 2005 and February 2010 from the baseline study of the Multi-Rural Communities Cohort Study in Rural Communities (MRCohort). A food frequency questionnaire was used to collect dietary information. Metabolic syndrome was defined using the modified criteria published in the Third Report of the National Cholesterol Education Program Adult Treatment Panel. RESULTS Calcium intake was related inversely to metabolic syndrome in women (P-value = 0.0091), but not in men (P = 0.1842). Among metabolic components, high waist circumference (WC) (P = 0.0426) and high blood glucose (P = 0.0027) in women and hypertriglyceridemia (P = 0.0017) in men were inversely correlated with calcium intake. Excluding those who used calcium or multinutrient supplements did not attenuate the relationship between dietary calcium and metabolic abnormalities. CONCLUSION Dietary calcium intake from foods may be inversely related to metabolic syndrome, WC, and blood glucose among women in rural areas of Korea. PMID:26060546

  18. Theory of acoustic propagation in a multi-phase stratified liquid flowing within an elastic-walled conduit of varying cross-sectional area

    NASA Astrophysics Data System (ADS)

    Garces, M. A.

    2000-08-01

    A theoretical solution is derived for the sound field in an arbitrarily layered viscous fluid moving with the non-negligible Mach number within a duct with elastic walls and varying cross-sectional area. The solution is applied to the interpretation of infrasonic and seismic signals preceding and accompanying volcanic eruptions, and can be used to study the acoustic response of various types of volcanic fluids, including magma-gas mixtures, ash-gas mixtures, and bubble-rich liquids. The acoustic field in a magma conduit can be propagated into the atmosphere through an open vent, and coupled into the ground through the displacement of the magma conduit walls. The theoretical solutions predict that fluids moving with the non-negligible Mach number will exhibit significant attenuation in the upstream direction, thereby reducing the quality factor of the conduit resonance. Thus, acoustic energy generated during an eruption may be preferentially radiated downstream, exacerbating the acoustic decoupling between the upper and lower parts of a stratified magma column. A source model for a repeated cavitation process is introduced as a possible excitation mechanism for tremor signals.

  19. Relationships of ultrasound measures of intrinsic foot muscle cross-sectional area and muscle volume with maximum toe flexor muscle strength and physical performance in young adults

    PubMed Central

    Abe, Takashi; Tayashiki, Kota; Nakatani, Miyuki; Watanabe, Hironori

    2016-01-01

    [Purpose] To investigate the relationships between toe flexor muscle strength with (TFS-5-toes) and without (TFS-4-toes) the contribution of the great toe, anatomical and physiological muscle cross-sectional areas (CSA) of intrinsic toe flexor muscle and physical performance were measured. [Subjects] Seventeen men (82% sports-active) and 17 women (47% sports-active), aged 20 to 35 years, volunteered. [Methods] Anatomical CSA was measured in two intrinsic toe flexor muscles (flexor digitorum brevis [FDB] and abductor hallucis) by ultrasound. Muscle volume and muscle length of the FDB were also estimated, and physiological CSA was calculated. [Results] Both TFS-5-toes and TFS-4-toes correlated positively with walking speed in men (r=0.584 and r=0.553, respectively) and women (r=0.748 and r=0.533, respectively). Physiological CSA of the FDB was significantly correlated with TFS-5-toes (r=0.748) and TFS-4-toes (r=0.573) in women. In men, physiological CSA of the FDB correlated positively with TFS-4-toes (r=0.536), but not with TFS-5-toes (r=0.333). [Conclusion] Our results indicate that physiological CSA of the FDB is moderately associated with TFS-4-toes while toe flexor strength correlates with walking performance. PMID:26957721

  20. Changes in Clinical Symptoms, Functions, and the Median Nerve Cross-Sectional Area at the Carpal Tunnel Inlet after Open Carpal Tunnel Release

    PubMed Central

    Koh, Young-Do; Kim, Jong Oh; Choi, Shin Woo

    2016-01-01

    Background The aim of this study was to investigate the relationship between clinical symptoms and cross-sectional area (CSA) of the median nerve at the carpal tunnel inlet before and after open carpal tunnel release (CTR). Methods Thirty-two patients (53 hands) that underwent open CTR for idiopathic carpal tunnel syndrome were prospectively enrolled. Median nerve CSA at the carpal tunnel inlet was measured preoperatively and at 2 and 12 weeks after CTR by high resolution ultrasonography. The Boston carpal tunnel questionnaire (BCTQ) was also completed at these times. Results BCTQ symptom (BCTQ-S) score was significantly improved at 2 weeks postoperatively, but BCTQ function (BCTQ-F) score and CSA were significantly improved at 12 weeks postoperatively. Preoperative CSA was significantly correlated with preoperative BCTQ-S and BCTQ-F scores but was not significantly correlated with postoperative BCTQ scores or postoperative changes in BCTQ scores. Postoperative median nerve CSA was not significantly correlated with postoperative BCTQ-S or BCTQ-F scores, and postoperative changes in median nerve CSA were not significantly correlated with postoperative changes in BCTQ-S or BCTQ-F scores. Conclusions The study shows clinical symptoms resolve rapidly after open CTR, but median nerve swelling and clinical function take several months to recover. In addition, preoperative median nerve swelling might predict preoperative severities of clinical symptoms and functional disabilities. However, postoperative reductions in median nerve swelling were not found to reflect postoperative reductions in clinical symptoms or functional disabilities. PMID:27583113

  1. On the mechanical power of joint extensions as affected by the change in muscle force (or cross-sectional area), ceteris paribus.

    PubMed

    Minetti, Alberto E

    2002-02-01

    This paper offers a reference prediction for the changes of mechanical power generated during a maximal (vertical, horizontal or inclined) joint extension, as a consequence of just the changes of muscle force or cross-sectional area (CSA). Ceteris paribus (all other things being equal), for a given joint, the exponents at which the force changes have to be raised to predict the duration, final speed and power of the maximal extension are -0.5, 0.5, and 1.5, respectively, for horizontal movements. For example, a force decrease of 30% leads to an increase of 19.5% of the duration of the extension and to a decrease of 16.3% and of 41.4% of its final speed and power. The equations for vertical or inclined extension performances are subject to the same exponents. However, the actual prediction is dependent upon the ratio between muscle strength and body weight, reflecting the fraction of the muscle strength (or CSA) acting against gravity during the manoeuvre. For instance, during a vertical extension, a force decrease of 30% leads to an increase of 30.9% of the duration of the extension and to a decrease of 29.3% and of 50.5% of its final speed and power. Based on the proposed model, a methodology is also described to detect the effects on the extension power of other determinants, in addition to CSA, of the useful force change (e.g. neuromuscular factors, motor control). PMID:11990751

  2. XCOM: Photon Cross Sections Database

    National Institute of Standards and Technology Data Gateway

    SRD 8 XCOM: Photon Cross Sections Database (Web, free access)   A web database is provided which can be used to calculate photon cross sections for scattering, photoelectric absorption and pair production, as well as total attenuation coefficients, for any element, compound or mixture (Z <= 100) at energies from 1 keV to 100 GeV.

  3. Chronic pain in the pelvic area or lower extremities after rectal cancer treatment and its impact on quality of life: a population-based cross-sectional study.

    PubMed

    Feddern, Marie-Louise; Jensen, Troels Staehelin; Laurberg, Søren

    2015-09-01

    The aim of this investigation was to examine the prevalence of and factors associated with chronic pain in the pelvic area or lower extremities after rectal cancer treatment and its impact on quality of life (QoL). This is a population-based cross-sectional study of chronic pain and QoL in patients treated for rectal cancer from 2001 to 2007. A modified version of the Brief Descriptive Danish Pain Questionnaire and the European Organization for Research and Treatment of Cancer QLQ-C30 questionnaire were mailed to 1713 Danish patients. Informative answers were obtained from 1369 patients (80%). A total of 426 patients (31%) reported chronic pain in the pelvic area or lower extremities, 173 (41%) of whom had daily pain. Pain in other parts of the body was associated with the presence of pain in the pelvic region (odds ratio [OR] 4.81 [3.63-6.38], P < 0.001). Multivariate logistic regression analysis showed an association with chronic pain in female patients (OR 1.91 [1.51-2.43], P < 0.001) and in those who received radio(chemo)therapy (OR 1.31 [1.01-1.7], P = 0.041) or underwent abdominoperineal excision (OR 1.71 [1.19-2.44], P = 0.003), total mesorectal excision (OR 1.39 [1.01-1.90], P = 0.041), and Hartmann procedure (OR 1.72 [1.04-2.84], P = 0.33) compared with partial mesorectal excision. Ordinal regression analysis showed a strong association between all QoL subgroups and pelvic pain. Chronic pain in the pelvic region or lower extremities after rectal cancer treatment is a common but largely neglected problem that is associated with female gender, type of surgery, radio(chemo)therapy, and young age, all of which impact the patient's QoL.

  4. Magnitude of Malaria and Factors among Febrile Cases in Low Transmission Areas of Hadiya Zone, Ethiopia: A Facility Based Cross Sectional Study

    PubMed Central

    Gone, Terefe Fuge; Leta, Taye Janfa

    2016-01-01

    Background Despite a remarkable decline in morbidity and mortality since the era of malaria roll back strategy, it still poses a huge challenge in Ethiopia in general and in Hadiya Zone in particular. Although, there are data from routine health management information on few indicators, there is scarcity of data showing magnitude of malaria and associated factors including knowledge and practice in the study area. Therefore, the aim of this study was to assess magnitude and factors affecting malaria in low transmission areas among febrile cases attending public health facilities in Hadiya Zone, Ethiopia. Methods A facility based cross-sectional study was conducted in Hadiya Zone from May 15 to June 15, 2014. Simple random sampling was used to select the health facility while systematic random sampling technique was used to reach febrile patients attending public health facilities. Data were collected by a pre-tested structured questionnaire containing sections of socio demographic risk factors and knowledge and prevention practices of malaria. Data were entered to Epi-Info software version 3.5.4 and exported to SPSS version 16 for descriptive and logistic regression analysis. Results One hundred six (25.8%) of participating febrile patients attending at sampled health facilities were found to have malaria by microscopy. Of which, P.vivax, P.falciparum and mixed infection accounted for 76(71. 7%), 27 (25.5%) and 3 (2.8%), respectively. History of travel to malaria endemic area, [AOR: 2.59, 95% CI: (1.24, 5.38)], not using bed net, [AOR: 4.67, 95%CI:, (2.11, 10.37)], poor practice related to malaria prevention and control, [AOR: 2.28, (95%CI: (1.10, 4.74)], poor knowledge about malaria, [AOR: 5.09,95%CI: (2.26,11.50)] and estimated distance of stagnant water near to the residence, [AOR: 3.32, (95%CI: (1.13, 9.76)] were significantly associated factors of malaria positivity in the study. Conclusion The present study revealed that malaria is still a major source of

  5. Prevalence and Risk Factors for Echinococcal Infection in a Rural Area of Northern Chile: A Household-Based Cross-Sectional Study

    PubMed Central

    Boufana, Belgees; Adones, Claudia; Bahamonde, Andrea; Abarca, Katia; Craig, Philip S.; Reiter-Owona, Ingrid

    2014-01-01

    Background Hydatidosis is a zoonotic disease of worldwide distribution caused by Echinococcus granulosus. Our study aimed to determine the prevalence of human and canine echinococcosis as well as the associated risk factors in a rural area of the Limarí province in northern Chile. Methodology/Principal Findings A cross-sectional study was conducted between August and November 2009 using a stratified sampling design in each of the five districts of the province. In the selected villages, up to 10 households were sampled. Serum and fecal samples from an adult family member and a dog were collected from each participating household. Risk factors were assessed by standardized questionnaires. Seroprevalence was assessed using a multi-step approach: an ELISA for screening, IFA, IHA and western blot for confirmation of results, respectively. The prevalence of echinococcal infection in dogs was determined by coproantigen genus specific ELISA. Chi-square, Fisher tests and logistic regressions were used to assess risk factors for human seropositivity and dog copropositivity. A seroprevalence of 2.6% (10/403) and coproprevalence of 28% (26/93) was recorded for humans and dogs respectively. Contact with dogs and dog feces were risk factors for human seropositivity while dog copropositivity was associated with home slaughter of livestock (OR = 3.35; CI 90%: 1.16–6.85) and households de-worming dogs (OR = 2.82; CI 90%: 1.33–8.43). Conclusions/Significance Echinococcal infection of humans and their dogs is common in Limarí province. Risk factors for human seropositivity were related to contact with domestic dogs and their feces, whereas those for dogs were home slaughter of livestock and the practice of de-worming dogs. PMID:25167140

  6. Impact of Perinatal Dioxin Exposure on Infant Growth: A Cross-Sectional and Longitudinal Studies in Dioxin-Contaminated Areas in Vietnam

    PubMed Central

    Nishijo, Muneko; Tai, Pham The; Nakagawa, Hideaki; Maruzeni, Shoko; Anh, Nguyen Thi Nguyet; Van Luong, Hoang; Anh, Tran Hai; Honda, Ryumon; Morikawa, Yuko; Kido, Teruhiko; Nishijo, Hisao

    2012-01-01

    Dioxin exposure levels remain elevated in residents living around former US Air Force bases in Vietnam, indicating potential adverse impacts on infant growth. In this study, 210 mother–infant pairs in dioxin-contaminated areas in Vietnam were recruited at the infants’ birth and followed up for 4 months. Perinatal dioxin exposure levels were estimated by measurement of polychlorinated dibenzo-p-dioxins/furans toxic equivalent (PCDDs/Fs-TEQ) in breast milk. The infants’ size was measured at birth and 1 and 4 months after birth, and neurodevelopment was evaluated using the Bayley Scales III at 4 months of age. Among 4 dioxin groups (<25, 25–50, 50–75, ≥75 percentile of PCDDs/Fs-TEQ), cross-sectional comparisons of body size and neurodevelopment scales and comparisons of longitudinally assessed body size were performed respectively. At birth, head circumference of girls in the ≥75 percentile group was significantly larger than those in the <25 and 50–75 percentile groups. At 4 months of age, the weight and body mass index (BMI) of boys in the ≥75 percentile group were significantly lower than those in the other groups. Increase in weight was significantly lower in the ≥75 percentile group in both sexes from birth to 1 month but only in boys at 1–4 months of age. Estimated marginal mean values in a mixed model of weight and BMI during the first 4 months of life were significantly lower in the ≥75 percentile group in boys. In girls, marginal mean values for head circumference were increased with increase in dioxin levels. Only in boys, cognitive, language, and fine motor scores in the ≥75 percentile group were significantly lower than those in the other groups. These results suggested a considerable impact of perinatal dioxin exposure on infant growth, particularly in boys exposed to dioxins at high level of PCDDs/Fs-TEQ. PMID:22815734

  7. Analysis of the dental morphology of Plio-Pleistocene hominids. II. Mandibular molars--study of cusp areas, fissure pattern and cross sectional shape of the crown.

    PubMed Central

    Wood, B A; Abbott, S A; Graham, S H

    1983-01-01

    Accurate measurements of the absolute and relative size of individual cusps, the arrangement of the primary fissure system and the shape of coronal cross sections of the tooth crown have been used to investigate the pattern of variation in Plio-Pleistocene hominid mandibular molar teeth. Teeth were either grouped into one of six taxonomic categories or considered as individual cases. Univariate analysis of relative cusp areas shows that the two taxonomic categories of 'robust' hominids from East and Southern Africa have relatively small mesial cusps, but a relatively large entoconid and hypoconulid and Principal Component plots of the data show that the 'robust' categories can be distinguished on the basis of relative cusp size. Other evidence suggests that these differences are not likely to be the result of allometric phenomena. Fissure pattern was analysed using the X/Y coordinates of defined reference points. Patterns were compared by Procrustes analysis and the relationships between teeth contained in the resulting similarity matrix were portrayed using Principal Coordinates plots and a nearest neighbours table. The positions of the posterior fovea and the mesial longitudinal fissure were important for distinguishing taxonomic categories. The shape of the coronal profiles proved difficult to quantify, but there were consistent and distinct differences between the South African 'robust' sample and teeth included within the East African Homo category. When these results are combined with those of a previous study of overall crown size and the distribution of extra cusps, they allow the affinities of isolated teeth or contentious specimens to be assessed. For example, our results show that KNM-ER 1506 and 1802 are more similar to the East African Homo group than any other category, and they indicate that though SK 1587 and 1588 are small teeth, they nonetheless are closest to the South African 'robust' category in terms of relative cusp size, fissure pattern and

  8. The cross-sectional area of the gluteus maximus muscle varies according to habitual exercise loading: Implications for activity-related and evolutionary studies.

    PubMed

    Niinimäki, Sirpa; Härkönen, Laura; Nikander, Riku; Abe, Shinya; Knüsel, Christopher; Sievänen, Harri

    2016-04-01

    Greater size of the gluteus maximus muscle in humans compared to non-human primates has been considered an indication of its function in bipedal posture and gait, especially running capabilities. Our aim was to find out how the size of the gluteus maximus muscle varies according to sports while controlling for variation in muscle strength and body weight. Data on gluteus maximus muscle cross-sectional area (MCA) were acquired from magnetic resonance images of the hip region of female athletes (N=91), and physically active controls (N=20). Dynamic muscle force was measured as counter movement jump and isometric knee extension force as leg press. Five exercise loading groups were created: high impact (triple-jumpers and high-jumpers), odd impact (soccer and squash players), high magnitude (power-lifters), repetitive impact (endurance runners) and repetitive non-impact (swimmers) loadings. Individuals in high impact, odd impact or high-magnitude loading groups had greater MCA compared to those of controls, requiring powerful hip extension, trunk stabilization in rapid directional change and high explosive muscle force. Larger body size and greater muscle strength were associated with larger MCA. An increase in dynamic force was associated with larger MCA, but the strength of this relationship varied with body weight. Thus, gluteal adaptation in humans promotes powerful lower limb movements required in sprinting and rapid changes in direction, as well as maintenance and stabilization of an erect trunk which also provides a platform for powerful motions of the upper limbs. These movements have likely evolved to facilitate food acquisition, including hunting. PMID:26384568

  9. Event-related differences in the cross-sectional areas and torque generation capabilities of quadriceps femoris and hamstrings in male high school athletes.

    PubMed

    Hoshikawa, Yoshihiro; Muramatsu, Masataka; Iida, Tomomi; Uchiyama, Akiko; Nakajima, Yoshiharu; Kanehisa, Hiroaki

    2010-01-01

    This study investigated the event-related differences in the cross-sectional areas (CSAs) and torque generation capabilities of the quadriceps femoris (QF) and hamstrings (HAM) in male high school athletes. Subjects were soccer players (n=32), volleyball players (21), rowers (29), karate athletes (18), sumo wrestlers (15), sprinters (22), throwers (16), and nonathletes (20). The CSAs of QF and HAM at the mid-thigh were determined using magnetic resonance imaging. In addition, isokinetic torques during knee extension and flexion were determined at a pre-set velocity of 1.05 rad/s. The CSAs of the two muscle groups and torques developed in the two motions were significantly related to the two-third power of lean body mass (LBM(2/3)) and the product of CSA and femur length (CSA*fl), calculated as an index of muscle volume, respectively. CSA relative to LBM(2/3) for QF did not differ among the groups, but that for HAM was higher in sprinters, soccer players, throwers, and karate athletes than in sumo wrestlers, rowers, volleyball players, and nonathletes. Knee extension torque relative to the CSA*fl of QF was higher in karate athletes, soccer players, and rowers than in nonathletes, but the corresponding value for knee flexion did not differ among groups. Thus, the present study indicated that, at least in male high school athletes, the event-related differences in LBM and the muscularity of QF and HAM produced the corresponding differences in the CSAs of the reciprocal muscle groups and knee extension and flexion torques, respectively. However, specific profiles related to competitive and/or training styles exist in HAM CSA and knee extension torque, which cannot be explained by the magnitude of LBM and QF CSA, respectively. PMID:20453429

  10. SU-E-I-25: Quantification of Coronary Artery Cross-Sectional Area in CT Angiography Using Integrated Density: A Simulation Study

    SciTech Connect

    Johnson, T; Ding, H; Lipinski, J; Molloi, S

    2015-06-15

    Purpose: To develop a physics-based model for accurate quantification of the cross-sectional area (CSA) of coronary arteries in CT angiography by measuring the integrated density to account for the partial volume effect. Methods: In this technique the integrated density of the object as compared with its local background is measured to account for the partial volume effect. Normal vessels were simulated as circles with diameters in the range of 0.1–3mm. Diseased vessels were simulated as 2, 3, and 4mm diameter vessels with 10–90% area stenosis, created by inserting circular plaques. A simplified two material model was used with the lumen as 8mg/ml Iodine and background as lipid. The contrast-to-noise ratio between lumen and background was approximately 26. Linear fits to the known CSA were calculated. The precision and accuracy of the measurement were quantified using the root-mean-square fit deviations (RMSD) and errors to the known CSA (RMSE). Results compared to manual segmentation of the vessel lumen. To assess the impact of random variations, coefficients of variation (CV) from 10 simulations for each vessel were computed to determine reliability. Measurements with CVs less than 10% were considered reliable. Results: For normal vessels, the precision and accuracy of the integrated density technique were 0.12mm{sup 2} and 0.28mm{sup 2}, respectively. The corresponding results for manual segmentation were 0.27mm{sup 2} and 0.43mm{sup 2}. For diseased vessels, the precision and accuracy of the integrated density technique were 0.14mm{sup 2} and 0.19mm{sup 2}. Corresponding results for manual segmentation were 0.42mm{sup 2} and 0.71mm{sup 2}. Reliable CSAs were obtained for normal vessels with diameters larger than 1 mm and for diseased vessels with area as low as 1.26mm2. Conclusion: The CSA based on integrated density showed improved precision and accuracy as compared with manual segmentation in simulation. These results indicate the potential of using

  11. Muscle torque relative to cross-sectional area and the functional muscle-bone unit in children and adolescents with chronic disease.

    PubMed

    Lee, Dale Y; Wetzsteon, Rachel J; Zemel, Babette S; Shults, Justine; Organ, Jason M; Foster, Bethany J; Herskovitz, Rita M; Foerster, Debbie L; Leonard, Mary B

    2015-03-01

    Measures of muscle mass or size are often used as surrogates of forces acting on bone. However, chronic diseases may be associated with abnormal muscle force relative to muscle size. The muscle-bone unit was examined in 64 children and adolescents with new-onset Crohn's disease (CD), 54 with chronic kidney disease (CKD), 51 treated with glucocorticoids for nephrotic syndrome (NS), and 264 healthy controls. Muscle torque was assessed by isometric ankle dynamometry. Calf muscle cross-sectional area (CSA) and tibia cortical section modulus (Zp) were assessed by quantitative CT. Log-linear regression was used to determine the relations among muscle CSA, muscle torque, and Zp, adjusted for tibia length, age, Tanner stage, sex, and race. Muscle CSA and muscle torque-relative-to-muscle CSA were significantly lower than controls in advanced CKD (CSA -8.7%, p = 0.01; torque -22.9%, p < 0.001) and moderate-to-severe CD (CSA -14.1%, p < 0.001; torque -7.6%, p = 0.05), but not in NS. Zp was 11.5% lower in advanced CKD (p = 0.005) compared to controls, and this deficit was attenuated to 6.7% (p = 0.05) with adjustment for muscle CSA. With additional adjustment for muscle torque and body weight, Zp was 5.9% lower and the difference with controls was no longer significant (p = 0.09). In participants with moderate-to-severe CD, Zp was 6.8% greater than predicted (p = 0.01) given muscle CSA and torque deficits (R(2)  = 0.92), likely due to acute muscle loss in newly-diagnosed patients. Zp did not differ in NS, compared with controls. In conclusion, muscle torque relative to muscle CSA was significantly lower in CKD and CD, compared with controls, and was independently associated with Zp. Future studies are needed to determine if abnormal muscle strength contributes to progressive bone deficits in chronic disease, independent of muscle area. © 2014 American Society for Bone and Mineral Research. PMID:25264231

  12. Muscle Torque Relative to Cross-Sectional Area and the Functional Muscle-Bone Unit in Children and Adolescents with Chronic Disease

    PubMed Central

    Lee, Dale Y.; Wetzsteon, Rachel J.; Zemel, Babette S.; Shults, Justine; Organ, Jason M.; Foster, Bethany J.; Herskovitz, Rita M.; Foerster, Debbie L.; Leonard, Mary B.

    2015-01-01

    Measures of muscle mass or size are often used as surrogates of forces acting on bone. However, chronic diseases may be associated with abnormal muscle force relative to muscle size. The muscle-bone unit was examined in 64 children and adolescents with new-onset Crohn’s disease (CD), 54 with chronic kidney disease (CKD), 51 treated with glucocorticoids for nephrotic syndrome (NS), and 264 healthy controls. Muscle torque was assessed by isometric ankle dynamometry. Calf muscle cross-sectional area (CSA) and tibia cortical section modulus (Zp) were assessed by quantitative CT. Log-linear regression was used to determine the relations among muscle CSA, muscle torque, and Zp, adjusted for tibia length, age, Tanner stage, sex, and race. Muscle CSA and muscle torque-relative-to-muscle CSA were significantly lower than controls in advanced CKD (CSA −8.7%, p = 0.01; torque −22.9%, p < 0.001) and moderate-to-severe CD (CSA −14.1%, p < 0.001; torque −7.6%, p = 0.05), but not in NS. Zp was 11.5% lower in advanced CKD (p = 0.005) compared to controls, and this deficit was attenuated to 6.7% (p = 0.05) with adjustment for muscle CSA. With additional adjustment for muscle torque and body weight, Zp was 5.9% lower and the difference with controls was no longer significant (p = 0.09). In participants with moderate-to-severe CD, Zp was 6.8% greater than predicted (p = 0.01) given muscle CSA and torque deficits (R2=0.92), likely due to acute muscle loss in newly diagnosed patients. Zp did not differ in NS, compared with controls. In conclusion, muscle torque relative to muscle CSA was significantly lower in CKD and CD, compared with controls, and was independently associated with Zp. Future studies are needed to determine if abnormal muscle strength contributes to progressive bone deficits in chronic disease, independent of muscle area. PMID:25264231

  13. Collision cross sectional areas from analysis of Fourier transform ion cyclotron resonance line width: a new method for characterizing molecular structure.

    PubMed

    Yang, Fan; Voelkel, Jacob E; Dearden, David V

    2012-06-01

    We demonstrate a technique for determining molecular collision cross sections via measuring the variation of Fourier transform ion cyclotron resonance (FTICR) line width with background damping gas pressure, under conditions where the length of the FTICR transient is pressure limited. Key features of our method include monoisotopic isolation of ions, the pulsed introduction of damping gas to a constant pressure using a pulsed leak valve, short excitation events to minimize collisions during the excitation, and proper choice of damping gas (Xe is superior to He). The measurements are reproducible within a few percent, which is sufficient for distinguishing between many structural possibilities and is comparable to the uncertainty in cross sections calculated from computed molecular structures. These techniques complement drift ion mobility measurements obtained on dedicated instruments. They do not require a specialized instrument, but should be easily performed on any FTICR mass spectrometer equipped with a pulsed leak valve.

  14. Hip Fractures Risk in Older Men and Women Associated With DXA-Derived Measures of Thigh Subcutaneous Fat Thickness, Cross-Sectional Muscle Area, and Muscle Density.

    PubMed

    Malkov, Serghei; Cawthon, Peggy M; Peters, Kathy Wilt; Cauley, Jane A; Murphy, Rachel A; Visser, Marjolein; Wilson, Joseph P; Harris, Tamara; Satterfield, Suzanne; Cummings, Steve; Shepherd, John A

    2015-08-01

    Mid-thigh cross-sectional muscle area (CSA), muscle attenuation, and greater trochanter soft tissue thickness have been shown to be independent risk factors of hip fracture. Our aim was to determine whether muscle and adipose tissue measures derived from dual-energy X-ray absorptiometry (DXA) scans would have a similar risk association as those measured using other imaging methods. Using a case-cohort study design, we identified 169 incident hip fracture cases over an average of 13.5 years among participants from the Health ABC Study, a prospective study of 3075 individuals initially aged 70 to 79 years. We modeled the thigh 3D geometry and compared DXA and computed tomography (CT) measures. DXA-derived thigh CSA, muscle attenuation, and subcutaneous fat thickness were found to be highly correlated to their CT counterparts (Pearson's r = 0.82, 0.45, and 0.91, respectively; p < 0.05). The fracture risk of men and women were calculated separately. We found that decreased subcutaneous fat, CT thigh muscle attenuation, and appendicular lean mass by height squared (ALM/Ht(2)) were associated with fracture risk in men; hazard ratios (HR) = 1.44 (1.02, 2.02), 1.40 (1.05, 1.85), and 0.58 (0.36, 0.91), respectively, after adjusting for age, race, clinical site, body mass index (BMI), chronic disease, hip bone mineral density (BMD), self-reported health, alcohol use, smoking status, education, physical activity, and cognitive function. In a similar model for women, only decreases in subcutaneous fat and DXA CSA were associated with hip fracture risk; HR = 1.39 (1.07, 1.82) and 0.78 (0.62, 0.97), respectively. Men with a high ALM/Ht(2) and low subcutaneous fat thickness had greater than 8 times higher risk for hip fracture compared with those with low ALM/Ht(2) and high subcutaneous fat. In women, ALM/Ht(2) did not improve the model when subcutaneous fat was included. We conclude that the DXA-derived subcutaneous fat thickness is a strong marker for hip fracture

  15. MRSA Carriage in Community Outpatients: A Cross-Sectional Prevalence Study in a High-Density Livestock Farming Area along the Dutch-German Border

    PubMed Central

    Paget, John; Aangenend, Helen; Kühn, Malte; Hautvast, Jeannine; van Oorschot, Desiree; Olde Loohuis, Alphons; van der Velden, Koos; Friedrich, Alexander W.; Voss, Andreas; Köck, Robin

    2015-01-01

    Objectives MRSA poses a considerable public health threat to the community. The objectives of this study were to assess the prevalence of MRSA carriage and determine factors that were associated with MRSA carriage among outpatients who had used antibiotics in the previous three months and who lived in a high-density livestock farming area along the Dutch-German border. Methods Cross-sectional prevalence study carried out between November 2011 and June 2012. Nasal swabs and questionnaires were collected in patients (>4 years) who had used antibiotics in the previous three months from twelve Dutch General Practitioners (GPs), seven German GPs and two German outpatient urologists. To assess nasal carriage, swabs were analyzed using selective MRSA agars after broth enrichment. MRSA positive samples were spa typed. Results Data were collected from 513 GP outpatients in the Netherlands, 261 GP outpatients in Germany and 200 urologist outpatients in Germany. The overall prevalence of MRSA carriage was 0.8%, 1.1% and 2.0%, respectively. In the GP outpatient populations, the prevalence was similar in both countries (0.8% and 1.1%, respectively, p = 0.879), all spa types were indicative for livestock-associated MRSA (4xt011 in the Netherlands; 2xt034 and t011 in Germany) and being a farmer, living on or near (<5km) to a farm were associated with MRSA carriage. In the urologist outpatient population, the prevalence was higher (2.0%), all spa types were indicative for healthcare-associated MRSA (t068, t032, t003, t10231) and being a farmer, living on or near to a farm were factors not associated with MRSA carriage. Conclusions The prevalence of MRSA carriage in these community outpatient populations along the Dutch-German border was low. There were striking similarities in livestock-associated MRSA carriage and clonal spread in the outpatient populations seeing their GP in both countries. In contrast, urologist outpatients in Germany were colonized with spa types indicative of

  16. Internal Jugular Vein Cross-Sectional Area and Cerebrospinal Fluid Pulsatility in the Aqueduct of Sylvius: A Comparative Study between Healthy Subjects and Multiple Sclerosis Patients

    PubMed Central

    Beggs, Clive B.; Magnano, Christopher; Belov, Pavel; Krawiecki, Jacqueline; Ramasamy, Deepa P.; Hagemeier, Jesper; Zivadinov, Robert

    2016-01-01

    Objectives Constricted cerebral venous outflow has been linked with increased cerebrospinal fluid (CSF) pulsatility in the aqueduct of Sylvius in multiple sclerosis (MS) patients and healthy individuals. This study investigates the relationship between CSF pulsatility and internal jugular vein (IJV) cross-sectional area (CSA) in these two groups, something previously unknown. Methods 65 relapsing-remitting MS patients (50.8% female; mean age = 43.8 years) and 74 healthy controls (HCs) (54.1% female; mean age = 43.9 years) were investigated. CSF flow quantification was performed on cine phase-contrast MRI, while IJV-CSA was calculated using magnetic resonance venography. Statistical analysis involved correlation, and partial least squares correlation analysis (PLSCA). Results PLSCA revealed a significant difference (p<0.001; effect size = 1.072) between MS patients and HCs in the positive relationship between CSF pulsatility and IJV-CSA at C5-T1, something not detected at C2-C4. Controlling for age and cardiovascular risk factors, statistical trends were identified in HCs between: increased net positive CSF flow (NPF) and increased IJV-CSA at C5-C6 (left: r = 0.374, p = 0.016; right: r = 0.364, p = 0.019) and C4 (left: r = 0.361, p = 0.020); and increased net negative CSF flow and increased left IJV-CSA at C5-C6 (r = -0.348, p = 0.026) and C4 (r = -0.324, p = 0.039), whereas in MS patients a trend was only identified between increased NPF and increased left IJV-CSA at C5-C6 (r = 0.351, p = 0.021). Overall, correlations were weaker in MS patients (p = 0.015). Conclusions In healthy adults, increased CSF pulsatility is associated with increased IJV-CSA in the lower cervix (independent of age and cardiovascular risk factors), suggesting a biomechanical link between the two. This relationship is altered in MS patients. PMID:27135831

  17. Accurate Cross Sections for Microanalysis

    PubMed Central

    Rez, Peter

    2002-01-01

    To calculate the intensity of x-ray emission in electron beam microanalysis requires a knowledge of the energy distribution of the electrons in the solid, the energy variation of the ionization cross section of the relevant subshell, the fraction of ionizations events producing x rays of interest and the absorption coefficient of the x rays on the path to the detector. The theoretical predictions and experimental data available for ionization cross sections are limited mainly to K shells of a few elements. Results of systematic plane wave Born approximation calculations with exchange for K, L, and M shell ionization cross sections over the range of electron energies used in microanalysis are presented. Comparisons are made with experimental measurement for selected K shells and it is shown that the plane wave theory is not appropriate for overvoltages less than 2.5 V. PMID:27446747

  18. Neutrino cross-sections: Experiments

    SciTech Connect

    Sánchez, F.

    2015-07-15

    Neutrino-nucleus cross-sections are as of today the main source of systematic errors for oscillation experiments together with neutrino flux uncertainties. Despite recent experimental and theoretical developments, future experiments require even higher precisions in their search of CP violation. We will review the experimental status and explore possible future developments required by next generation of experiments.

  19. [USE OF CONTRACEPTION IN WOMEN FROM THE ZAPRESIĆ AREA AND FACTORS INFLUENCING THE CHOICE OF METHOD: A CROSS-SECTIONAL STUDY].

    PubMed

    Benčić, Miro; Vrcić-Keglević, Mladenka

    2014-12-01

    There have long been no surveys in the field of family planning in Croatia. There were some carried out by commercial agencies and some related to adolescents, but none focused on women of reproductive age. Therefore, we embarked upon this survey including women living in the town of Zaprešić and its surroundings. The aims of the study were to investigate how many of them used contraception, which methods prevailed, how they made their choice and whether demographic and health care characteristics had have any influence on it. This cross-sectional survey was conducted at eight family medicine practices from the town of Zaprešić town and six practices from nearby rural settings. We used a purposeful sampling method; women aged 18-45 visiting family medicine practices for different reasons were asked to participate in the study. Those that agreed were given a questionnaire designed for this survey and based on literature results. The questions were closed and related to the women's demographic and some health-related characteristics and those related to the usage of contraception, such as the method used, how they made their choice, if they made any changes and why. The STATA/IC 11.2 (license 30110536846) was used on data processing. Descriptive statistics was used with Pearson χ2-test and logistic regression analysis to determine associations between categorical variables and dependent variable, in this case contraception use or non-use. The value of p < 0.05 was considered significant. Out of 283 women having filled in the questionnaire, 44.5% used some contraceptive methods. The most frequently used was condom (24.7%), then pill (24.1%) and combination of several methods (20.0%). The women living in the town used more coitus interruptus, and those living in rural areas used more pills. The most frequently stated reasons for the use of certain methods were as follows: the methods is simple for use (32.9%), it is safe (24.6%), and it is efficient and safe (22

  20. Socioeconomic disadvantage increasing risk for depression among recently diagnosed HIV patients in an urban area in Brazil: cross-sectional study.

    PubMed

    Nomoto, Silmara Harumi; Longhi, Renata Marrona Praça; de Barros, Bruna Paes; Croda, Julio; Ziff, Edward Benjamin; Castelon Konkiewitz, Elisabete

    2015-01-01

    Depression is the most common psychiatric co-morbidity among people living with HIV (PLHIV), with prevalence rates ranging from 25% to 36%. Depression impacts negatively upon adherence and response to combined antiretroviral therapy (CART) and the transmission of HIV infection through increased sexually risky behavior. This cross-sectional study presents data from a reference HIV-outpatient service in Dourados (Brazil) that evaluated the association between depressive symptoms, health-related quality of life, and clinical, socioeconomic, and demographic factors in newly diagnosed HIV/AIDS patients. Using the Beck Depression Inventory (BDI), the prevalence of depressive symptoms was 61% with a predominance of self-deprecating and cognitive-affective factors. Depressive symptoms were associated with lower income (p=0.019) and disadvantaged social class (p=0.005). Poorer quality of life was related to depressive symptoms (p<0.0001), low educational level (p=0.05), and lower income (p=0.03). These data suggest that socioeconomic factors, including level of income and education, are mediating the risk of depression and poor quality of life of PLHIV. Possible explanations for this effect are discussed, including the possible role of stigma. PMID:25741909

  1. Recommended Dosimetry Cross Section Compendium.

    1994-07-11

    Version 00 The data is recommended for spectrum determination applications and for the prediction of neutron activation of typical radiation sensor materials. The library has been tested for consistency of the cross sections in a wide variety of neutron environments. The results and cautions from this testing have been documented. The data has been interfaced with radiation transport codes, such as TWODANT-SYS (CCC-547) and MCNP (CCC-200), in order to compare calculated and measured activities formore » benchmark reactor experiments.« less

  2. Electron-Impact Ionization Cross Section Database

    National Institute of Standards and Technology Data Gateway

    SRD 107 Electron-Impact Ionization Cross Section Database (Web, free access)   This is a database primarily of total ionization cross sections of molecules by electron impact. The database also includes cross sections for a small number of atoms and energy distributions of ejected electrons for H, He, and H2. The cross sections were calculated using the Binary-Encounter-Bethe (BEB) model, which combines the Mott cross section with the high-incident energy behavior of the Bethe cross section. Selected experimental data are included.

  3. Active tuberculosis case finding and detection of drug resistance among HIV-infected patients: A cross-sectional study in a TB endemic area, Gondar, Northwest Ethiopia

    PubMed Central

    Alemayehu, Martha; Gelaw, Baye; Abate, Ebba; Wassie, Liya; Belyhun, Yeshambel; Bekele, Shiferaw; Kempker, Russell R.; Blumberg, Henry M.; Aseffa, Abraham

    2016-01-01

    Background Tuberculosis (TB) patients co-infected with human immunodeficiency virus (HIV) often lack the classic symptoms of pulmonary tuberculosis, making the diagnosis difficult. Current practices in resource-limited settings often indicate that these co-infected patients are diagnosed when they clinically manifest disease symptoms, resulting in a delayed diagnosis and despite continued transmission. The aim of this study is to determine the prevalence of undiagnosed pulmonary tuberculosis cases through active case finding and including multidrug-resistant TB (MDR-TB) among HIV-infected patients. Materials and methods A total of 250 HIV-infected patients, aged 18 years and above were evaluated in a cross-sectional design between February 2012 and November 2012. Socio-demographic and clinical data were collected using a structured questionnaire. Sputum samples were collected from all participants for acid fast bacilli (AFB) direct smear microscopy and Mycobacteria culture. A PCR-based RD9 deletion and genus typing, as well as first-line anti-TB drug susceptibility testing, was performed for all culture-positive isolates. Results Following active TB case finding, a total of 15/250 (6%) cases were diagnosed as TB cases, of whom 9/250 (3.6%) were detected by both smear microscopy and culture and the remaining 6/250 (2.4%) only by culture. All the 15 isolates were typed through RD9 typing of which 10 were Mycobacterium tuberculosis species; 1 belonged to Mycobacterium genus and 4 isolates were non-tuberculous mycobacteria. The prevalence of undiagnosed pulmonary TB disease among the study participants was 4.4%, which implies the possibility of identifying even more undiagnosed cases through active case finding. A multivariate logistic regression showed a statistically significant association between the presence of pneumonia infection and the occurrence of TB (OR = 4.81, 95% CI (1.08–21.43), p = 0.04). In addition, all the isolates were sensitive to all first

  4. Terahertz radar cross section measurements.

    PubMed

    Iwaszczuk, Krzysztof; Heiselberg, Henning; Jepsen, Peter Uhd

    2010-12-01

    We perform angle- and frequency-resolved radar cross section (RCS) measurements on objects at terahertz frequencies. Our RCS measurements are performed on a scale model aircraft of size 5-10 cm in polar and azimuthal configurations, and correspond closely to RCS measurements with conventional radar on full-size objects. The measurements are performed in a terahertz time-domain system with freely propagating terahertz pulses generated by tilted pulse front excitation of lithium niobate crystals and measured with sub-picosecond time resolution. The application of a time domain system provides ranging information and also allows for identification of scattering points such as weaponry attached to the aircraft. The shapes of the models and positions of reflecting parts are retrieved by the filtered back projection algorithm.

  5. Electron Photon Interaction Cross Sections

    2014-11-01

    Version 00 The Electron Photon Interaction Cross Sections, EPICS, provides the atomic data needed to perform coupled Electron-Photon transport calculations, to produce accurate macroscopic results, such as energy deposit and dose. Atomic data is provided for elements, Z = 1 to 100, over the energy range 10 eV to 100 GeV; note that nuclear data, such as photo-nuclear, and data for compounds, are not included. All data is in a simple computer independent text formatmore » that is standard and presented to a high precision that can be easily read by computer codes written in any computer language, e.g., C, C++, and FORTRAN. EPICS includes four separate data bases that are designed to be used in combination, these include, • The Evaluated Electron Data Library (EEDL), to describe the interaction of electrons with matter. • The Evaluated Photon Data Library (EPDL), to describe the interaction of photons with matter. • The Evaluated Atomic Data Library (EADL), to describe the emission of electrons and photons back to neutrality following an ionizing event, caused by either electron or photon interactions. • The Evaluated Excitation Data Library (EXDL), to describe the excitation of atoms due to photon interaction. All of these are available in the Extended ENDL format (ENDLX) in which the evaluations were originally performed. The first three are also available in the ENDF format; as yet ENDF does not include formats to handle excitation data (EXDL).« less

  6. Electron Photon Interaction Cross Sections

    SciTech Connect

    Cullen, D. E.

    2014-11-01

    Version 00 The Electron Photon Interaction Cross Sections, EPICS, provides the atomic data needed to perform coupled Electron-Photon transport calculations, to produce accurate macroscopic results, such as energy deposit and dose. Atomic data is provided for elements, Z = 1 to 100, over the energy range 10 eV to 100 GeV; note that nuclear data, such as photo-nuclear, and data for compounds, are not included. All data is in a simple computer independent text format that is standard and presented to a high precision that can be easily read by computer codes written in any computer language, e.g., C, C++, and FORTRAN. EPICS includes four separate data bases that are designed to be used in combination, these include, • The Evaluated Electron Data Library (EEDL), to describe the interaction of electrons with matter. • The Evaluated Photon Data Library (EPDL), to describe the interaction of photons with matter. • The Evaluated Atomic Data Library (EADL), to describe the emission of electrons and photons back to neutrality following an ionizing event, caused by either electron or photon interactions. • The Evaluated Excitation Data Library (EXDL), to describe the excitation of atoms due to photon interaction. All of these are available in the Extended ENDL format (ENDLX) in which the evaluations were originally performed. The first three are also available in the ENDF format; as yet ENDF does not include formats to handle excitation data (EXDL).

  7. [Fast neutron cross section measurements

    SciTech Connect

    Knoll, G.F.

    1992-10-26

    From its inception, the Nuclear Data Project at the University of Michigan has concentrated on two major objectives: (1) to carry out carefully controlled nuclear measurements of the highest possible reliability in support of the national nuclear data program, and (2) to provide an educational opportunity for students with interests in experimental nuclear science. The project has undergone a successful transition from a primary dependence on our photoneutron laboratory to one in which our current research is entirely based on a unique pulsed 14 MeV fast neutron facility. The new experimental facility is unique in its ability to provide nanosecond bursts of 14 MeV neutrons under conditions that are clean'' and as scatter-free as possible, and is the only one of its type currently in operation in the United States. It has been designed and put into operation primarily by graduate students, and has met or exceeded all of its important initial performance goals. We have reached the point of its routine operation, and most of the data are now in hand that will serve as the basis for the first two doctoral dissertations to be written by participating graduate students. Our initial results on double differential neutron cross sections will be presented at the May 1993 Fusion Reactor Technology Workshop. We are pleased to report that, after investing several years in equipment assembly and optimization, the project has now entered its data production'' phase.

  8. Local Deplanation Of Double Reinforced Beam Cross Section Under Bending

    NASA Astrophysics Data System (ADS)

    Baltov, Anguel; Yanakieva, Ana

    2015-12-01

    Bending of beams, double reinforced by means of thin composite layers, is considered in the study. Approximate numerical solution is proposed, considering transitional boundary areas, where smooth quadratic transition of the elasticity modulus and deformations take place. Deplanation of the cross section is also accounted for in the areas. Their thickness is found equalizing the total stiffness of the cross section and the layer stiffness. Deplanation of the cross section of the transitional area is determined via the longitudinal deformation in the reinforcing layer, accounting for the equilibrium between the internal and the external moment, generated by the longitudinal stresses in the cross section. A numerical example is given as an illustration demonstrating model's plausibility. The model allows the design and the calculation of recycled concrete beams double reinforced by means of thin layers. The approach is in agreement with modern design of nearly zero energy buildings (NZEB).

  9. Recent fission cross section standards measurements

    SciTech Connect

    Wasson, O.A.

    1985-01-01

    The /sup 235/U(n,f) reaction is the standard by which most neutron induced fission cross sections are determined. Most of these cross sections are derived from relatively easy ratio measurements to /sup 235/U. However, the more difficult /sup 235/U(n,f) cross section measurements require the use of advanced neutron detectors for the determination of the incident neutron fluence. Examples of recent standard cross section measurements are discussed, various neutron detectors are described, and the status of the /sup 235/U(n,f) cross section standard is assessed. 23 refs., 8 figs., 4 tabs.

  10. Quantitative Computed Tomography Measures of Pectoralis Muscle Area and Disease Severity in Chronic Obstructive Pulmonary Disease. A Cross-Sectional Study

    PubMed Central

    McDonald, Merry-Lynn N.; Diaz, Alejandro A.; Ross, James C.; San Jose Estepar, Raul; Zhou, Linfu; Regan, Elizabeth A.; Eckbo, Eric; Muralidhar, Nina; Come, Carolyn E.; Cho, Michael H.; Hersh, Craig P.; Lange, Christoph; Wouters, Emiel; Casaburi, Richard H.; Coxson, Harvey O.; MacNee, William; Rennard, Stephen I.; Lomas, David A.; Agusti, Alvar; Celli, Bartolome R.; Black-Shinn, Jennifer L.; Kinney, Greg L.; Lutz, Sharon M.; Hokanson, John E.; Silverman, Edwin K.

    2014-01-01

    Rationale: Muscle wasting in chronic obstructive pulmonary disease (COPD) is associated with a poor prognosis and is not readily assessed by measures of body mass index (BMI). BMI does not discriminate between relative proportions of adipose tissue and lean muscle and may be insensitive to early pathologic changes in body composition. Computed tomography (CT)–based assessments of the pectoralis muscles may provide insight into the clinical significance of skeletal muscles in smokers. Objectives: We hypothesized that objective assessment of the pectoralis muscle area on chest CT scans provides information that is clinically relevant and independent of BMI. Methods: Data from the ECLIPSE (Evaluation of COPD Longitudinally to Identify Predictive Surrogate Endpoints) Study (n = 73) were used to assess the relationship between pectoralis muscle area and fat-free mass. We then used data in a subset (n = 966) of a larger cohort, the COPDGene (COPD Genetic Epidemiology) Study, to explore the relationship between pectoralis muscle area and COPD-related traits. Measurements and Main Results: We first investigated the correlation between pectoralis muscle area and fat-free mass, using data from a subset of participants in the ECLIPSE Study. We then further investigated pectoralis muscle area in COPDGene Study participants and found that higher pectoralis muscle area values were associated with greater height, male sex, and younger age. On subsequent clinical correlation, compared with BMI, pectoralis muscle area was more significantly associated with COPD-related traits, including spirometric measures, dyspnea, and 6-minute-walk distance (6MWD). For example, on average, each 10-cm2 increase in pectoralis muscle area was associated with a 0.8-unit decrease in the BODE (Body mass index, Obstruction, Dyspnea, Exercise) index (95% confidence interval, –1.0 to –0.6; P < 0.001). Furthermore, statistically significant associations between pectoralis muscle area and COPD

  11. Medical and nursing students' intentions to work abroad or in rural areas: a cross-sectional survey in Asia and Africa

    PubMed Central

    Blevins, Meridith; Afzal, Arfan R; Andrews, Ben; Derbew, Miliard; Kaur, Simran; Mipando, Mwapatsa; Mkony, Charles A; Mwachaka, Philip M; Ranjit, Nirju; Vermund, Sten

    2014-01-01

    Abstract Objective To assess medical and nursing students’ intentions to migrate abroad or practice in rural areas. Methods We surveyed 3199 first- and final-year medical and nursing students at 16 premier government institutions in Bangladesh, Ethiopia, India, Kenya, Malawi, Nepal, the United Republic of Tanzania and Zambia. The survey contained questions to identify factors that could predict students’ intentions to migrate. Primary outcomes were the likelihoods of migrating to work abroad or working in rural areas in the country of training within five years post-training. We assessed predictors of migration intentions using multivariable proportional odds models. Findings Among respondents, 28% (870/3156) expected to migrate abroad, while only 18% (575/3158) anticipated a rural career. More nursing than medical students desired professions abroad (odds ratio, OR: 1.76; 95% confidence interval, CI: 1.25–2.48). Career desires before matriculation correlated with current intentions for international (OR: 4.49; 95% CI: 3.21–6.29) and rural (OR: 4.84; 95% CI: 3.52–6.66) careers. Time spent in rural areas before matriculation predicted the preference for a rural career (20 versus 0 years: OR: 1.53, 95% CI: 1.19–1.98) and against work abroad (20 versus 0 years: OR: 0.69, 95% CI: 0.50–0.96). Conclusion A significant proportion of students surveyed still intend to work abroad or in cities after training. These intentions could be identified even before matriculation. Admissions standards that account for years spent in rural areas could promote greater graduate retention in the country of training and in rural areas. PMID:25378729

  12. Cross-sectional Biomonitoring of Metals in Adult Populations in Post-war Eastern Croatia: Differences Between Areas of Moderate and Heavy Combat

    PubMed Central

    Jergović, Matijana; Miškulin, Maja; Puntarić, Dinko; Gmajnić, Rudika; Milas, Josip; Sipos, Laszlo

    2010-01-01

    Aim To determine differences in metal and metalloid exposure between residents of areas in eastern Croatia exposed to heavy fighting during the war in Croatia and residents of areas exposed to moderate fighting. Methods Concentrations of aluminum (Al), arsenic (As), barium (Ba), cadmium (Cd), chromium (Cr), copper (Cu), iron (Fe), nickel (Ni), lead (Pb), uranium (U), vanadium (V), and zinc (Zn), reported to be associated with military operations, were determined in hair, serum, and urine samples using inductively-coupled plasma mass spectroscopy. A total of 127 and 46 participants from areas of heavy and moderate fighting, respectively, were included. Results Compared with participants from areas exposed to moderate fighting, participants from areas exposed to heavy fighting had significantly higher serum concentrations of Al (87.61 vs 42.75 μg/L, P = 0.007), As (5.05 ± 1.79 vs 4.16 ± 1.55 μg/L, P = 0.003), Ba (7.12 vs 6.01 μg/L, P = 0.044), and V (17.98 vs 16.84 μg/L, P = 0.008); significantly higher urine concentrations of As (43.90 vs 11.51 μg/L, P < 0.001) and Cd (0.67 vs 0.50 μg/L, P = 0.031); and significantly higher hair concentrations of Al (12.61 vs 7.33 μg/L, P < 0.001), As (0.32 vs 0.05 μg/L, P < 0.001), Cd (0.03 vs 0.02 μg/L, P = 0.002), Fe (22.58 vs 12.68 μg/L, P = 0.001), Pb (1.04 vs 0.69 μg/L, P = 0.006), and V (0.07 vs 0.03 μg/L, P < 0.001). Conclusion Differences between populations from eastern Croatian areas exposed to heavy and populations exposed to moderate fighting point to the need for extensive monitoring of metal and metalloid exposure, emphasizing the role of biomonitoring through ecologic and preventive activities. PMID:20960595

  13. Area deprivation and the food environment over time: A repeated cross-sectional study on takeaway outlet density and supermarket presence in Norfolk, UK, 1990–2008

    PubMed Central

    Maguire, Eva R.; Burgoine, Thomas; Monsivais, Pablo

    2015-01-01

    Socioeconomic disparities in the food environment are known to exist but with little understanding of change over time. This study investigated the density of takeaway food outlets and presence of supermarkets in Norfolk, UK between 1990 and 2008. Data on food retail outlet locations were collected from telephone directories and aggregated within electoral wards. Supermarket presence was not associated with area deprivation over time. Takeaway food outlet density increased overall, and was significantly higher in more deprived areas at all time points; furthermore, socioeconomic disparities in takeaway food outlet density increased across the study period. These findings add to existing evidence and help assess the need for environmental interventions to reduce disparities in the prevalence of unhealthy food outlets. PMID:25841285

  14. Area deprivation and the food environment over time: A repeated cross-sectional study on takeaway outlet density and supermarket presence in Norfolk, UK, 1990-2008.

    PubMed

    Maguire, Eva R; Burgoine, Thomas; Monsivais, Pablo

    2015-05-01

    Socioeconomic disparities in the food environment are known to exist but with little understanding of change over time. This study investigated the density of takeaway food outlets and presence of supermarkets in Norfolk, UK between 1990 and 2008. Data on food retail outlet locations were collected from telephone directories and aggregated within electoral wards. Supermarket presence was not associated with area deprivation over time. Takeaway food outlet density increased overall, and was significantly higher in more deprived areas at all time points; furthermore, socioeconomic disparities in takeaway food outlet density increased across the study period. These findings add to existing evidence and help assess the need for environmental interventions to reduce disparities in the prevalence of unhealthy food outlets.

  15. The impact of area residential property values on self-rated health: A cross-sectional comparative study of Seattle and Paris.

    PubMed

    Jiao, Junfeng; Drewnowski, Adam; Moudon, Anne Vernez; Aggarwal, Anju; Oppert, Jean-Michel; Charreire, Helene; Chaix, Basile

    2016-12-01

    This study analyzed the impact of area residential property values, an objective measure of socioeconomic status (SES), on self-rated health (SRH) in Seattle, Washington and Paris, France. This study brings forth a valuable comparison of SRH between cities that have contrasting urban forms, population compositions, residential segregation, food systems and transportation modes. The SOS (Seattle Obesity Study) was based on a representative sample of 1394 adult residents of Seattle and King County in the United States. The RECORD Study (Residential Environment and Coronary Heart Disease) was based on 7131 adult residents of Paris and its suburbs in France. Socio-demographics, SRH and body weights were obtained from telephone surveys (SOS) and in-person interviews (RECORD). All home addresses were geocoded using ArcGIS 9.3.1 (ESRI, Redlands, CA). Residential property values were obtained from tax records (Seattle) and from real estate sales (Paris). Binary logistic regression models were used to test the associations among demographic and SES variables and SRH. Higher area property values significantly associated with better SRH, adjusting for age, gender, individual education, incomes, and BMI. The associations were significant for both cities. A one-unit increase in body mass index (BMI) was more detrimental to SRH in Seattle than in Paris. In both cities, higher area residential property values were related to a significantly lower obesity risk and better SRH. Ranked residential property values can be useful for health and weight studies, including those involving social inequalities and cross-country comparisons.

  16. The impact of area residential property values on self-rated health: A cross-sectional comparative study of Seattle and Paris.

    PubMed

    Jiao, Junfeng; Drewnowski, Adam; Moudon, Anne Vernez; Aggarwal, Anju; Oppert, Jean-Michel; Charreire, Helene; Chaix, Basile

    2016-12-01

    This study analyzed the impact of area residential property values, an objective measure of socioeconomic status (SES), on self-rated health (SRH) in Seattle, Washington and Paris, France. This study brings forth a valuable comparison of SRH between cities that have contrasting urban forms, population compositions, residential segregation, food systems and transportation modes. The SOS (Seattle Obesity Study) was based on a representative sample of 1394 adult residents of Seattle and King County in the United States. The RECORD Study (Residential Environment and Coronary Heart Disease) was based on 7131 adult residents of Paris and its suburbs in France. Socio-demographics, SRH and body weights were obtained from telephone surveys (SOS) and in-person interviews (RECORD). All home addresses were geocoded using ArcGIS 9.3.1 (ESRI, Redlands, CA). Residential property values were obtained from tax records (Seattle) and from real estate sales (Paris). Binary logistic regression models were used to test the associations among demographic and SES variables and SRH. Higher area property values significantly associated with better SRH, adjusting for age, gender, individual education, incomes, and BMI. The associations were significant for both cities. A one-unit increase in body mass index (BMI) was more detrimental to SRH in Seattle than in Paris. In both cities, higher area residential property values were related to a significantly lower obesity risk and better SRH. Ranked residential property values can be useful for health and weight studies, including those involving social inequalities and cross-country comparisons. PMID:27413663

  17. Association between wheeze and selected air pollution sources in an air pollution priority area in South Africa: a cross-sectional study

    PubMed Central

    2014-01-01

    Background An association between wheeze (a symptom of asthma) and environmental tobacco smoke (ETS), types of fuel used for residential heating or cooking and the frequency of trucks passing near homes, has been reported mainly in developed countries. Little is known about the strength of such associations in developing countries. This study was conducted in residential areas situated in Ekurhuleni Metropolitan Municipality, namely Tembisa and Kempton Park, which form part of the Highveld region, a priority area in terms of air pollution in South Africa. Methods From 3764 eligible school children, aged between 13 and 14 years, from 16 selected high schools in the study area, 3468 completed a modified questionnaire based on the International Study of Asthma and Allergies in Childhood (ISAAC). Data were analysed using multiple logistic regression models. Results The results are based on data from 3424 children. In the adjusted models, exposure to ETS at school was associated with wheeze ever (OR 1.22 95% CI: 1.03 - 1.45) and current wheeze (OR 1.33 95% CI: 1.08 - 1.64). When gas was most frequently used for residential heating the likelihood of wheeze ever increased by 47% (OR 1.47 95% CI: 1.15 - 1.88). Trucks passing near homes for almost the whole day during weekdays, increased the likelihood of wheeze ever (OR 1.32 95% CI: 1.01 - 1.73), current wheeze (OR 1.61 95% CI: 1.15 - 2.24) and current severe wheeze (OR 2.22 95% CI: 1.28 - 3.77). When data were stratified according to residential area, for children living in Tembisa, ETS exposure at home was associated with current wheeze (OR 1.36 95% CI: 1.06 - 1.77); gas most frequently used for residential heating was associated with wheeze ever (OR 1.68 95% CI: 1.23 - 2.28) and current wheeze (OR 1.61 95% CI: 1.08 - 2.39); paraffin most frequently used for residential heating was associated with current severe wheeze (OR 1.85 95% CI: 1.04 - 3.28). Conclusion It was concluded that children living in one of the air

  18. COPD and its association with smoking in the Mainland China: a cross-sectional analysis of 0.5 million men and women from ten diverse areas

    PubMed Central

    Kurmi, Om P; Li, Liming; Wang, Jenny; Millwood, Iona Y; Chen, Junshi; Collins, Rory; Guo, Yu; Bian, Zheng; Li, Jiangtao; Chen, Biyun; Xie, Kaixu; Jia, Weifan; Gao, Yali; Peto, Richard; Chen, Zhengming

    2015-01-01

    Purpose In adult Chinese men, smoking prevalence is high, but little is known about its association with chronic respiratory disease, which is still poorly diagnosed and managed. Methods A nationwide study recruited 0.5 million men and women aged 30–79 years during 2004–2008 from ten geographically diverse areas across the Mainland China. Information was collected from each participant regarding smoking and self-reported physician diagnosis of chronic bronchitis/emphysema (CB/E), along with measurement of lung function indices. Logistic regression was used to yield sex-specific odds ratios (ORs) relating smoking to airflow obstruction (AFO), defined as forced expiratory volume in 1 second (FEV1)/forced vital capacity (FVC) <0.7 and CB/E, adjusting for age, areas, education, and income. Results Overall 74% of men were ever regular smokers; among them, 7.2% had AFO compared with 5.4% in never-smokers, yielding an OR of 1.42 (95% confidence interval [CI]: 1.34–1.50). The risk was strongly associated with amount smoked and starting to smoke at a younger age. Among ex-smokers, the OR was more extreme for those who had quit due to illness (OR: 1.86, 95% CI: 1.77–1.96) than those who had quit by choice (OR:1.08, 95% CI: 1.01–1.16). CB/E prevalence was also significantly elevated in ex-smokers who had quit because of ill health (OR:2.79, 95% CI: 2.64–2.95), but not in regular smokers (OR:1.04, 95% CI: 0.96–1.11). Female smokers was rare (3%), but carried an excess risk for AFO (OR:1.53, 95% CI: 1.43–1.65) and, to a lesser extent, for CB/E (OR:1.28, 95% CI: 1.15–1.42). Conclusion In Mainland China, adult smokers, particularly ex-smokers who had quit because of illness, had significantly higher prevalence of chronic respiratory disease. AFO appeared to be more strongly associated with smoking than self-reported chronic respiratory disease. PMID:25848242

  19. Vertically stabilized elongated cross-section tokamak

    DOEpatents

    Sheffield, George V.

    1977-01-01

    This invention provides a vertically stabilized, non-circular (minor) cross-section, toroidal plasma column characterized by an external separatrix. To this end, a specific poloidal coil means is added outside a toroidal plasma column containing an endless plasma current in a tokamak to produce a rectangular cross-section plasma column along the equilibrium axis of the plasma column. By elongating the spacing between the poloidal coil means the plasma cross-section is vertically elongated, while maintaining vertical stability, efficiently to increase the poloidal flux in linear proportion to the plasma cross-section height to achieve a much greater plasma volume than could be achieved with the heretofore known round cross-section plasma columns. Also, vertical stability is enhanced over an elliptical cross-section plasma column, and poloidal magnetic divertors are achieved.

  20. Joint effects of urinary arsenic methylation capacity with potential modifiers on arsenicosis: a cross-sectional study from an endemic arsenism area in Huhhot Basin, northern China.

    PubMed

    Zhang, Qiang; Wang, Da; Zheng, Quanmei; Zheng, Yi; Wang, Huihui; Xu, Yuanyuan; Li, Xin; Sun, Guifan

    2014-07-01

    A lower arsenic methylation capacity is believed to be associated with various arsenic-related diseases. However, the synergistic effect of the arsenic methylation capacity and potential modifiers on arsenicosis risk is unclear. The current study evaluated the joint effect of the arsenic methylation capacity with several risk factors on the risk of arsenicosis characterized by skin lesions. In total, 302 adults (79 arsenicosis and 223 non-arsenicosis) residing in an endemic arsenism area in Huhhot Basin were included. Urinary levels of inorganic arsenic (iAs), monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA) were determined, and the percentages of arsenic species (iAs%, MMA%, and DMA%), as well as two methylation indices (primary methylation index, PMI, and secondary methylation index, SMI), were calculated to assess the arsenic methylation capacity of individuals. The results showed that a lower methylation capacity, which is indicated by higher MMA% values and lower DMA% and SMI values, was significantly associated with arsenicosis after the adjustment for multiple confounders. The relative excess risk for interactions between higher MMA% values and older age was 2.35 (95% CI: -0.56, 5.27), and the relative excess risk for interactions between higher MMA% values and lower BMI was 1.08 (95% CI: -1.20, 3.36). The data also indicated a suggestive synergistic effect of a lower arsenic methylation capacity (lower DMA% and SMI) with older age, lower BMI, and male gender. The findings of the present study suggest that a lower arsenic methylation capacity was associated with arsenicosis and that certain risk factors may enhance the risk of arsenic-induced skin lesions. PMID:24834823

  1. Joint effects of urinary arsenic methylation capacity with potential modifiers on arsenicosis: a cross-sectional study from an endemic arsenism area in Huhhot Basin, northern China.

    PubMed

    Zhang, Qiang; Wang, Da; Zheng, Quanmei; Zheng, Yi; Wang, Huihui; Xu, Yuanyuan; Li, Xin; Sun, Guifan

    2014-07-01

    A lower arsenic methylation capacity is believed to be associated with various arsenic-related diseases. However, the synergistic effect of the arsenic methylation capacity and potential modifiers on arsenicosis risk is unclear. The current study evaluated the joint effect of the arsenic methylation capacity with several risk factors on the risk of arsenicosis characterized by skin lesions. In total, 302 adults (79 arsenicosis and 223 non-arsenicosis) residing in an endemic arsenism area in Huhhot Basin were included. Urinary levels of inorganic arsenic (iAs), monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA) were determined, and the percentages of arsenic species (iAs%, MMA%, and DMA%), as well as two methylation indices (primary methylation index, PMI, and secondary methylation index, SMI), were calculated to assess the arsenic methylation capacity of individuals. The results showed that a lower methylation capacity, which is indicated by higher MMA% values and lower DMA% and SMI values, was significantly associated with arsenicosis after the adjustment for multiple confounders. The relative excess risk for interactions between higher MMA% values and older age was 2.35 (95% CI: -0.56, 5.27), and the relative excess risk for interactions between higher MMA% values and lower BMI was 1.08 (95% CI: -1.20, 3.36). The data also indicated a suggestive synergistic effect of a lower arsenic methylation capacity (lower DMA% and SMI) with older age, lower BMI, and male gender. The findings of the present study suggest that a lower arsenic methylation capacity was associated with arsenicosis and that certain risk factors may enhance the risk of arsenic-induced skin lesions.

  2. Prevalence of Frailty and Aging-Related Health Conditions in Older Koreans in Rural Communities: a Cross-Sectional Analysis of the Aging Study of Pyeongchang Rural Area.

    PubMed

    Jung, Hee-Won; Jang, Il-Young; Lee, Young Soo; Lee, Chang Ki; Cho, Eun-Il; Kang, Woo Young; Chae, Jeoung Hee; Lee, Eun Ju; Kim, Dae Hyun

    2016-03-01

    Frailty has been previously studied in Western countries and the urban Korean population; however, the burden of frailty and geriatric conditions in the aging populations of rural Korean communities had not yet been determined. Thus, we established a population-based prospective study of adults aged ≥ 65 years residing in rural communities of Korea between October 2014 and December 2014. All participants underwent comprehensive geriatric assessment that encompassed the assessment of cognitive and physical function, depression, nutrition, and body composition using bioimpedance analysis. We determined the prevalence of frailty based on the Cardiovascular Health Study (CHS) and Korean version of FRAIL (K-FRAIL) criteria, as well as geriatric conditions. We recruited 382 adults (98% of eligible adults; mean age: 74 years; 56% women). Generally, sociodemographic characteristics were similar to those of the general rural Korean population. Common geriatric conditions included instrumental activity of daily living disability (39%), malnutrition risk (38%), cognitive dysfunction (33%), multimorbidity (32%), and sarcopenia (28%), while dismobility (8%), incontinence (8%), and polypharmacy (3%) were less common conditions. While more individuals were classified as frail according to the K-FRAIL criteria (27%) than the CHS criteria (17%), the CHS criteria were more strongly associated with prevalent geriatric conditions. Older Koreans living in rural communities have a significant burden of frailty and geriatric conditions that increase the risk of functional decline, poor quality of life, and mortality. The current study provides a basis to guide public health professionals and policy-makers in prioritizing certain areas of care and designing effective public health interventions to promote healthy aging of this vulnerable population. PMID:26952571

  3. Prevalence of Frailty and Aging-Related Health Conditions in Older Koreans in Rural Communities: a Cross-Sectional Analysis of the Aging Study of Pyeongchang Rural Area

    PubMed Central

    2016-01-01

    Frailty has been previously studied in Western countries and the urban Korean population; however, the burden of frailty and geriatric conditions in the aging populations of rural Korean communities had not yet been determined. Thus, we established a population-based prospective study of adults aged ≥ 65 years residing in rural communities of Korea between October 2014 and December 2014. All participants underwent comprehensive geriatric assessment that encompassed the assessment of cognitive and physical function, depression, nutrition, and body composition using bioimpedance analysis. We determined the prevalence of frailty based on the Cardiovascular Health Study (CHS) and Korean version of FRAIL (K-FRAIL) criteria, as well as geriatric conditions. We recruited 382 adults (98% of eligible adults; mean age: 74 years; 56% women). Generally, sociodemographic characteristics were similar to those of the general rural Korean population. Common geriatric conditions included instrumental activity of daily living disability (39%), malnutrition risk (38%), cognitive dysfunction (33%), multimorbidity (32%), and sarcopenia (28%), while dismobility (8%), incontinence (8%), and polypharmacy (3%) were less common conditions. While more individuals were classified as frail according to the K-FRAIL criteria (27%) than the CHS criteria (17%), the CHS criteria were more strongly associated with prevalent geriatric conditions. Older Koreans living in rural communities have a significant burden of frailty and geriatric conditions that increase the risk of functional decline, poor quality of life, and mortality. The current study provides a basis to guide public health professionals and policy-makers in prioritizing certain areas of care and designing effective public health interventions to promote healthy aging of this vulnerable population. PMID:26952571

  4. Prevalence of Frailty and Aging-Related Health Conditions in Older Koreans in Rural Communities: a Cross-Sectional Analysis of the Aging Study of Pyeongchang Rural Area.

    PubMed

    Jung, Hee-Won; Jang, Il-Young; Lee, Young Soo; Lee, Chang Ki; Cho, Eun-Il; Kang, Woo Young; Chae, Jeoung Hee; Lee, Eun Ju; Kim, Dae Hyun

    2016-03-01

    Frailty has been previously studied in Western countries and the urban Korean population; however, the burden of frailty and geriatric conditions in the aging populations of rural Korean communities had not yet been determined. Thus, we established a population-based prospective study of adults aged ≥ 65 years residing in rural communities of Korea between October 2014 and December 2014. All participants underwent comprehensive geriatric assessment that encompassed the assessment of cognitive and physical function, depression, nutrition, and body composition using bioimpedance analysis. We determined the prevalence of frailty based on the Cardiovascular Health Study (CHS) and Korean version of FRAIL (K-FRAIL) criteria, as well as geriatric conditions. We recruited 382 adults (98% of eligible adults; mean age: 74 years; 56% women). Generally, sociodemographic characteristics were similar to those of the general rural Korean population. Common geriatric conditions included instrumental activity of daily living disability (39%), malnutrition risk (38%), cognitive dysfunction (33%), multimorbidity (32%), and sarcopenia (28%), while dismobility (8%), incontinence (8%), and polypharmacy (3%) were less common conditions. While more individuals were classified as frail according to the K-FRAIL criteria (27%) than the CHS criteria (17%), the CHS criteria were more strongly associated with prevalent geriatric conditions. Older Koreans living in rural communities have a significant burden of frailty and geriatric conditions that increase the risk of functional decline, poor quality of life, and mortality. The current study provides a basis to guide public health professionals and policy-makers in prioritizing certain areas of care and designing effective public health interventions to promote healthy aging of this vulnerable population.

  5. Association between ambient noise exposure and school performance of children living in an urban area: a cross-sectional population-based study.

    PubMed

    Pujol, Sophie; Levain, Jean-Pierre; Houot, Hélène; Petit, Rémy; Berthillier, Marc; Defrance, Jérôme; Lardies, Joseph; Masselot, Cyril; Mauny, Frédéric

    2014-04-01

    Most of the studies investigating the effects of the external noise on children's school performance have concerned pupils in schools exposed to high levels due to aircraft or freeway traffic noise. However, little is known about the consequences of the chronic ambient noise exposure at a level commonly encountered in residential urban areas. This study aimed to assess the relationship between the school performance of 8- to 9-year-old-children living in an urban environment and their chronic ambient noise exposure at home and at school. The children's school performances on the national standardized assessment test in French and mathematics were compared with the environmental noise levels. Children's exposure to ambient noise was calculated in front of their bedrooms (Lden) and schools (LAeq,day) using noise prediction modeling. Questionnaires were distributed to the families to collect potential confounding factors. Among the 746 respondent children, 586 were included in multilevel analyses. On average, the LAeq,day at school was 51.5 dB (SD= 4.5 dB; range = 38-58 dB) and the outdoor Lden at home was 56.4 dB (SD= 4.4 dB; range = 44-69 dB). LAeq,day at school was associated with impaired mathematics score (p = 0.02) or impaired French score (p = 0.01). For a + 10 dB gap, the French and mathematics scores were on average lower by about 5.5 points. Lden at home was significantly associated with impaired French performance when considered alone (p < 10(-3)) and was borderline significant when the combined home-school exposure was considered (p = 0.06). The magnitude of the observed effect on school performance may appear modest, but should be considered in light of the number of people who are potentially chronically exposed to similar environmental noise levels. PMID:24190106

  6. Association between ambient noise exposure and school performance of children living in an urban area: a cross-sectional population-based study.

    PubMed

    Pujol, Sophie; Levain, Jean-Pierre; Houot, Hélène; Petit, Rémy; Berthillier, Marc; Defrance, Jérôme; Lardies, Joseph; Masselot, Cyril; Mauny, Frédéric

    2014-04-01

    Most of the studies investigating the effects of the external noise on children's school performance have concerned pupils in schools exposed to high levels due to aircraft or freeway traffic noise. However, little is known about the consequences of the chronic ambient noise exposure at a level commonly encountered in residential urban areas. This study aimed to assess the relationship between the school performance of 8- to 9-year-old-children living in an urban environment and their chronic ambient noise exposure at home and at school. The children's school performances on the national standardized assessment test in French and mathematics were compared with the environmental noise levels. Children's exposure to ambient noise was calculated in front of their bedrooms (Lden) and schools (LAeq,day) using noise prediction modeling. Questionnaires were distributed to the families to collect potential confounding factors. Among the 746 respondent children, 586 were included in multilevel analyses. On average, the LAeq,day at school was 51.5 dB (SD= 4.5 dB; range = 38-58 dB) and the outdoor Lden at home was 56.4 dB (SD= 4.4 dB; range = 44-69 dB). LAeq,day at school was associated with impaired mathematics score (p = 0.02) or impaired French score (p = 0.01). For a + 10 dB gap, the French and mathematics scores were on average lower by about 5.5 points. Lden at home was significantly associated with impaired French performance when considered alone (p < 10(-3)) and was borderline significant when the combined home-school exposure was considered (p = 0.06). The magnitude of the observed effect on school performance may appear modest, but should be considered in light of the number of people who are potentially chronically exposed to similar environmental noise levels.

  7. Annular-Cross-Section CFE Chamber

    NASA Technical Reports Server (NTRS)

    Sharnez, Rizwan; Sammons, David W.

    1994-01-01

    Proposed continuous-flow-electrophoresis (CFE) chamber of annular cross section offers advantages over conventional CFE chamber, and wedge-cross-section chamber described in "Increasing Sensitivity in Continuous-Flow Electrophoresis" (MFS-26176). In comparison with wedge-shaped chamber, chamber of annular cross section virtually eliminates such wall effects as electro-osmosis and transverse gradients of velocity. Sensitivity enhanced by incorporating gradient maker and radial (collateral) flow.

  8. Theoretical antideuteron-nucleus absorptive cross sections

    NASA Technical Reports Server (NTRS)

    Buck, W. W.; Norbury, J. W.; Townsend, L. W.; Wilson, J. W.

    1993-01-01

    Antideuteron-nucleus absorptive cross sections for intermediate to high energies are calculated using an ion-ion optical model. Good agreement with experiment (within 15 percent) is obtained in this same model for (bar p)-nucleus cross sections at laboratory energies up to 15 GeV. We describe a technique for estimating antinucleus-nucleus cross sections from NN data and suggest that further cosmic ray studies to search for antideuterons and other antinuclei be undertaken.

  9. Cross Sections for Electron Collisions with Methane

    SciTech Connect

    Song, Mi-Young Yoon, Jung-Sik; Cho, Hyuck; Itikawa, Yukikazu; Karwasz, Grzegorz P.; Kokoouline, Viatcheslav; Nakamura, Yoshiharu; Tennyson, Jonathan

    2015-06-15

    Cross section data are compiled from the literature for electron collisions with methane (CH{sub 4}) molecules. Cross sections are collected and reviewed for total scattering, elastic scattering, momentum transfer, excitations of rotational and vibrational states, dissociation, ionization, and dissociative attachment. The data derived from swarm experiments are also considered. For each of these processes, the recommended values of the cross sections are presented. The literature has been surveyed through early 2014.

  10. Do Trunk Muscles Affect the Lumbar Interbody Fusion Rate?: Correlation of Trunk Muscle Cross Sectional Area and Fusion Rates after Posterior Lumbar Interbody Fusion Using Stand-Alone Cage

    PubMed Central

    Choi, Man Kyu; Park, Bong Jin; Park, Chang Kyu; Kim, Sung Min

    2016-01-01

    Objective Although trunk muscles in the lumbar spine preserve spinal stability and motility, little is known about the relationship between trunk muscles and spinal fusion rate. The aim of the present study is to evaluate the correlation between trunk muscles cross sectional area (MCSA) and fusion rate after posterior lumbar interbody fusion (PLIF) using stand-alone cages. Methods A total of 89 adult patients with degenerative lumbar disease who were performed PLIF using stand-alone cages at L4–5 were included in this study. The cross-sectional area of the psoas major (PS), erector spinae (ES), and multifidus (MF) muscles were quantitatively evaluated by preoperative lumbar magnetic resonance imaging at the L3–4, L4–5, and L5–S1 segments, and bone union was evaluated by dynamic lumbar X-rays. Results Of the 89 patients, 68 had bone union and 21 did not. The MCSAs at all segments in both groups were significantly different (p<0.05) for the PS muscle, those at L3–4 and L4–5 segments between groups were significantly different (p=0.048, 0.021) for the ES and MF muscles. In the multivariate analysis, differences in the PS MCSA at the L4–5 and L5–S1 segments remained significant (p=0.048, 0.043 and odds ratio=1.098, 1.169). In comparison analysis between male and female patients, most MCSAs of male patients were larger than female's. Fusion rates of male patients (80.7%) were higher than female's (68.8%), too. Conclusion For PLIF surgery, PS muscle function appears to be an important factor for bone union and preventing back muscle injury is essential for better fusion rate. PMID:27226860

  11. Correlation cross sections along the international border

    SciTech Connect

    Martiniuk, C.D. ); Le Fever, J.A.; Anderson, S.B. )

    1991-06-01

    The Manitoba-North Dakota (Canada-US) stratigraphic correlation project is a joint study between the Petroleum Branch of Manitoba Energy and Mines and the North Dakota Geological Survey. It is an attempt to correlate the differing stratigraphic terminologies established in the two jurisdictions by providing a reference cross section across the international boundary. The study involves the subsurface correlation of logs of the Paleozoic and Mesozoic sequences in the Manitoba and North Dakota portions of the Williston basin. The Paleozoic and Mesozoic sequences are subdivided for presentation into the following stratigraphic intervals: (a) Cambrian-Ordovician-Silurian, (b) Devonian, (c) Mississippian, (d) Jurassic, and (e) Cretaceous. Wireline logs show the actual stratigraphic correlations. A nomenclature chart is also presented from each sequence. In addition, the sections include a generalized description of lithologies, thicknesses, environments of deposition, and petroleum potential for each geographic area.

  12. Nasal airway responses to nasal continuous positive airway pressure breathing: An in-vivo pilot study.

    PubMed

    White, David E; Bartley, Jim; Shakeel, Muhammad; Nates, Roy J; Hankin, Robin K S

    2016-06-14

    The nasal cycle, through variation in nasal airflow partitioning, allows the upper airway to accommodate the contrasting demands of air conditioning and removal of entrapped air contaminants. The purpose of this study was to investigate the influence of nasal continuous positive airway pressure (nCPAP) breathing has on both nasal airflow partitioning and nasal geometry. Using a custom-made nasal mask, twenty healthy participants had the airflow in each naris measured during normal nasal breathing followed by nCPAP breathing. Eight participants also underwent magnetic resonance imaging (MRI) of the nasal region during spontaneous nasal breathing, and then nCPAP breathing over a range of air pressures. During nCPAP breathing, a simultaneous reduction in airflow through the patent airway together with a corresponding increase in airway flow within the congested nasal airway were observed in sixteen of the twenty participants. Nasal airflow resistance is inversely proportional to airway cross-sectional area. MRI data analysis during nCPAP breathing confirmed airway cross-sectional area reduced along the patent airway while the congested airway experienced an increase in this parameter. During awake breathing, nCPAP disturbs the normal inter-nasal airflow partitioning. This could partially explain the adverse nasal drying symptoms frequently reported by many users of this therapy. PMID:27173595

  13. Absolute partial photoionization cross sections of ozone.

    SciTech Connect

    Berkowitz, J.; Chemistry

    2008-04-01

    Despite the current concerns about ozone, absolute partial photoionization cross sections for this molecule in the vacuum ultraviolet (valence) region have been unavailable. By eclectic re-evaluation of old/new data and plausible assumptions, such cross sections have been assembled to fill this void.

  14. Preliminary cross section of Englebright Lake sediments

    USGS Publications Warehouse

    Snyder, Noah P.; Hampton, Margaret A.

    2003-01-01

    Overview -- The Upper Yuba River Studies Program is a CALFED-funded, multidisciplinary investigation of the feasibility of introducing anadromous fish species to the Yuba River system upstream of Englebright Dam. Englebright Lake (Figure 1 on poster) is a narrow, 14-km-long reservoir located in the northern Sierra Nevada, northeast of Marysville, CA. The dam was completed in 1941 for the primary purpose of trapping sediment derived from mining operations in the Yuba River watershed. Possible management scenarios include lowering or removing Englebright Dam, which could cause the release of stored sediments and associated contaminants, such as mercury used extensively in 19th-century hydraulic gold mining. Transport of released sediment to downstream areas could increase existing problems including flooding and mercury bioaccumulation in sport fish. To characterize the extent, grain size, and chemistry of this sediment, a coring campaign was done in Englebright Lake in May and June 2002. More than twenty holes were drilled at 7 different locations along the longitudinal axis of the reservoir (Figure 4 on poster), recovering 6 complete sequences of post-reservoir deposition and progradation. Here, a longitudinal cross section of Englebright Lake is presented (Figure 5 on poster), including pre-dam and present-day topographic profiles, and sedimentologic sections for each coring site. This figure shows the deltaic form of the reservoir deposit, with a thick upper section consisting of sand and gravel overlying silt, a steep front, and a thinner lower section dominated by silt. The methodologies used to create the reservoir cross section are discussed in the lower part of this poster.

  15. Experience With the SCALE Criticality Safety Cross Section Libraries

    SciTech Connect

    Bowman, S.M.

    2000-08-21

    This report provides detailed information on the SCALE criticality safety cross-section libraries. Areas covered include the origins of the libraries, the data on which they are based, how they were generated, past experience and validations, and performance comparisons with measured critical experiments and numerical benchmarks. The performance of the SCALE criticality safety cross-section libraries on various types of fissile systems are examined in detail. Most of the performance areas are demonstrated by examining the performance of the libraries vs critical experiments to show general trends and weaknesses. In areas where directly applicable critical experiments do not exist, performance is examined based on the general knowledge of the strengths and weaknesses of the cross sections. In this case, the experience in the use of the cross sections and comparisons with the results of other libraries on the same systems are relied on for establishing acceptability of application of a particular SCALE library to a particular fissile system. This report should aid in establishing when a SCALE cross-section library would be expected to perform acceptably and where there are known or suspected deficiencies that would cause the calculations to be less reliable. To determine the acceptability of a library for a particular application, the calculational bias of the library should be established by directly applicable critical experiments.

  16. Silicon Detector System for Cross Section Measurements

    NASA Technical Reports Server (NTRS)

    2003-01-01

    In order to estimate the radiation shielding effectiveness of materials it is necessary to know cosmic ray particles are broken up as they pass though these materials. The breakup of cosmic ray particles is characterized by the nuclear fragmentation cross sections, i.e. an effective geometrical cross section assigned to each target nucleus that represents its apparent size for fragmenting the incident particle. The values of these cross sections depend on the details of nuclear physics and cannot be calculated from first principles owing to the many-body nature of the interactions. The only way to determine them is to measure them. Once a sufficient number of cross sections have been measured, the systematic nature of the interactions allows other cross-sections to be estimated. The number of cross sections that contribute to the estimation of shielding effectiveness is very large 10,000. Fortunately most make minor contributions. These can be estimated from nuclear systematics. Only those who's uncertainties make significant contributions to the error in the shielding effectiveness estimations need to be measured. In the past it has proven difficult to measure light fragment production cross sections from the interactions of heavy cosmic rays owing to the size of the detectors used. We have developed a highly pixilated silicon (Si) detector system that can individually identify these light fragments while making efficient use of costly accelerator time. This system is an outgrowth of detector technology developed under a CDDF and a Code S sponsored cosmic ray experiment.

  17. Cross Section Evaluations for Arsenic Isotopes

    SciTech Connect

    Pruet, J; McNabb, D P; Ormand, W E

    2005-03-10

    The authors present an evaluation of cross sections describing reactions with neutrons incident on the arsenic isotopes with mass numbers 75 and 74. Particular attention is paid to (n,2n) reactions. The evaluation for {sup 75}As, the only stable As isotope, is guided largely by experimental data. Evaluation for {sup 74}As is made through calculations with the EMPIRE statistical-model reaction code. Cross sections describing the production and destruction of the 26.8 ns isomer in {sup 74}As are explicitly considered. Uncertainties and covariances in some evaluated cross sections are also estimated.

  18. Differential cross-sections with hard targets

    NASA Astrophysics Data System (ADS)

    Brun, J. L.; Pacheco, A. F.

    2005-09-01

    When the concept of scattering differential cross-section is introduced in classical mechanics textbooks, usually it is first supposed that the target is a fixed, hard sphere. In this paper we calculate the scattering differential cross-section in the case of the hard target being a fixed figure of revolution of any shape. When the target is a paraboloid of revolution, we find the well-known formula corresponding to Rutherford's scattering. In addition, we analyse the inverse problem, i.e. given a differential cross-section, what is the profile of the corresponding hard target?

  19. Bibliography of photoabsorption cross-section data

    NASA Technical Reports Server (NTRS)

    Hudson, R. D.; Kieffer, L. J.

    1970-01-01

    This bibliography contains only references which report a measured or calculated photoabsorption cross section (relative or normalized) in regions of continuous absorption. The bibliography is current as of January 1, 1970.

  20. Absorption cross section of canonical acoustic holes

    SciTech Connect

    Crispino, Luis C. B.; Oliveira, Ednilton S.; Matsas, George E. A.

    2007-11-15

    We compute numerically the absorption cross section of a canonical acoustic hole for sound waves with arbitrary frequencies. Our outputs are in full agreement with the expected low- and high-frequency limits.

  1. MODELING AND FISSION CROSS SECTIONS FOR AMERICIUM.

    SciTech Connect

    ROCHMAN, D.; HERMAN, M.; OBLOZINSKY, P.

    2005-05-01

    This is the final report of the work performed under the LANL contract on the modeling and fission cross section for americium isotopes (May 2004-June 2005). The purpose of the contract was to provide fission cross sections for americium isotopes with the nuclear reaction model code EMPIRE 2.19. The following work was performed: (1) Fission calculations capability suitable for americium was implemented to the EMPIRE-2.19 code. (2) Calculations of neutron-induced fission cross sections for {sup 239}Am to {sup 244g}Am were performed with EMPIRE-2.19 for energies up to 20 MeV. For the neutron-induced reaction of {sup 240}Am, fission cross sections were predicted and uncertainties were assessed. (3) Set of fission barrier heights for each americium isotopes was chosen so that the new calculations fit the experimental data and follow the systematics found in the literature.

  2. The radar cross section of dielectric disks

    NASA Technical Reports Server (NTRS)

    Levine, D. M.

    1982-01-01

    A solution is presented for the backscatter (nonstatic) radar cross section of dielectric disks of arbitrary shape, thickness and dielectric constant. The result is obtained by employing a Kirchhoff type approximation to obtain the fields inside the disk. The internal fields induce polarization and conduction currents from which the scattered fields and the radar cross section can be computed. The solution for the radar cross section obtained in this manner is shown to agree with known results in the special cases of normal incidence, thin disks and perfect conductivity. The solution can also be written as a product of the reflection coefficient of an identically oriented slab times the physical optics solution for the backscatter cross section of a perfectly conducting disk of the same shape. This result follows directly from the Kirchhoff type approximation without additional assumptions.

  3. International Evaluation of Neutron Cross Section Standards

    NASA Astrophysics Data System (ADS)

    Carlson, A. D.; Pronyaev, V. G.; Smith, D. L.; Larson, N. M.; Chen, Zhenpeng; Hale, G. M.; Hambsch, F.-J.; Gai, E. V.; Oh, Soo-Youl; Badikov, S. A.; Kawano, T.; Hofmann, H. M.; Vonach, H.; Tagesen, S.

    2009-12-01

    Neutron cross section standards are the basis for the determination of most neutron cross sections. They are used for both measurements and evaluations of neutron cross sections. Not many cross sections can be obtained absolutely - most cross sections are measured relative to the cross section standards and converted using evaluations of the standards. The previous complete evaluation of the neutron cross section standards was finished in 1987 and disseminated as the NEANDC/INDC and ENDF/B-VI standards. R-matrix model fits for the light elements and non-model least-squares fits for all the cross sections in the evaluation were the basis of the combined fits for all of the data. Some important reactions and constants are not standards, but they assist greatly in the determination of the standard cross sections and reduce their uncertainties - these data were also included in the combined fits. The largest experimental database used in the evaluation was prepared by Poenitz and included about 400 sets of experimental data with covariance matrices of uncertainties that account for all cross-energy, cross-reaction and cross-material correlations. For the evaluation GMA, a least-squares code developed by Poenitz, was used to fit all types of cross sections (absolute and shape), their ratios, spectrum-averaged cross sections and thermal constants in one full analysis. But, the uncertainties derived in this manner, and especially those obtained in the R-matrix model fits, have been judged to be too low and unrealistic. These uncertainties were substantially increased prior to their release in the recommended data files of 1987. Modified percentage uncertainties were reassigned by the United States Cross Section Evaluation Working Group's Standards Subcommittee for a wide range of energies, and no covariance (or correlation) matrices were supplied at that time. The need to re-evaluate the cross section standards is based on the appearance of a significant amount of precise

  4. A nuclear cross section data handbook

    SciTech Connect

    Fisher, H.O.M.

    1989-12-01

    Isotopic information, reaction data, data availability, heating numbers, and evaluation information are given for 129 neutron cross-section evaluations, which are the source of the default cross sections for the Monte Carlo code MCNP. Additionally, pie diagrams for each nuclide displaying the percent contribution of a given reaction to the total cross section are given at 14 MeV, 1 MeV, and thermal energy. Other information about the evaluations and their availability in continuous-energy, discrete-reaction, and multigroup forms is provided. The evaluations come from ENDF/B-V, ENDL85, and the Los Alamos Applied Nuclear Science Group T-2. Graphs of all neutron and photon production cross-section reactions for these nuclides have been categorized and plotted. 21 refs., 5 tabs.

  5. Ultraviolet absorption cross sections of hydrogen peroxide

    NASA Technical Reports Server (NTRS)

    Lin, C. L.; Rohatgi, N. K.; Demore, W. B.

    1978-01-01

    Absorption cross-sections of hydrogen peroxide vapor and of neutral aqueous solutions of hydrogen peroxide were measured in the wavelength range from 195 to 350 nm at 296 K. The spectrophotometric procedure is described, and the reported cross-sections are compared with values obtained by other researchers. Photodissociation coefficients of atmospheric H2O2 were calculated for direct absorption of unscattered solar radiation, and the vertical distributions of these coefficients are shown for various solar zenith angles.

  6. QuickSite Cross Section Processing

    2003-05-27

    This AGEM-developed system produces cross sections by inputting data in both standard and custom file formats and outputting a graphic file that can be printed or further modified in a commercial graphic program. The system has evolved over several years in order to combine and visualize a changing set of field data more rapidly than was possible with commercially available cross section software packages. It uses some commercial packages to produce the input and tomore » modify the output files. Flexibility is provided by a dynamic set of programs that are customized to accept varying input and accomodate varying output requirements. There are two basic types of routines: conversion routines and cross section generation routines. The conversion routines convery various data files to logger file format which is compatible with a standard file format for LogPlot 98, a commonly used commercial log plotting program. The cross section routines generate cross sections and apply topography to these cross sections. All of the generation routines produce a standard graphic DXF file, which is the format used in AutoCAD and can then be modified in a number of available graphics programs.« less

  7. Theoretical Formalism To Estimate the Positron Scattering Cross Section.

    PubMed

    Singh, Suvam; Dutta, Sangita; Naghma, Rahla; Antony, Bobby

    2016-07-21

    A theoretical formalism is introduced in this article to calculate the total cross sections for positron scattering. This method incorporates positron-target interaction in the spherical complex optical potential formalism. The study of positron collision has been quite subtle until now. However, recently, it has emerged as an interesting area due to its role in atomic and molecular structure physics, astrophysics, and medicine. With the present method, the total cross sections for simple atoms C, N, and O and their diatomic molecules C2, N2, and O2 are obtained and compared with existing data. The total cross section obtained in the present work gives a more consistent shape and magnitude than existing theories. The characteristic dip below 10 eV is identified due to the positronium formation. The deviation of the present cross section with measurements at energies below 10 eV is attributed to the neglect of forward angle-discrimination effects in experiments, the inefficiency of additivity rule for molecules, empirical treatment of positronium formation, and the neglect of annihilation reactions. In spite of these deficiencies, the present results show consistent behavior and reasonable agreement with previous data, wherever available. Besides, this is the first computational model to report positron scattering cross sections over the energy range from 1 to 5000 eV. PMID:27333337

  8. Effects of Spinal Stabilization Exercise on the Cross-sectional Areas of the Lumbar Multifidus and Psoas Major Muscles, Pain Intensity, and Lumbar Muscle Strength of Patients with Degenerative Disc Disease

    PubMed Central

    Kim, Seongho; Kim, Hyungguen; Chung, Jaeyeop

    2014-01-01

    [Purpose] The aim of this study was to evaluate the efficacy of using spinal stabilizing exercise to reduce atrophy of the multifidus and psoas major muscles, reduce the levels of pain and disability, and increase paraspinal muscle strength in patients with degenerative disc disease (DDD). [Subjects and Methods] In 33 patients (Age range: 25–65 years) diagnosed with DDD, spinal stabilization exercise was conducted for 8 weeks. The levels of pain and disability were measured before and after exercise using the visual analogue scale (VAS) and the Oswestry Disability Index (ODI). Paraspinal muscular strength in four directions was evaluated with a CENTAUR 3D Spatial Rotation Device. Cross-sectional areas (CSAs) of both the left and right multifidus and the psoas major at the upper endplate of L4 were measured before and after exercise using computed tomography (CT). [Results] After 8 weeks of spinal stabilization exercise, the pain and lumbar disability in subjects decreased significantly from 6.12±1.24 to 2.43±1.14. The ODI score also improved from 20.18±7.14 to 8.81±5.73. In addition, paraspinal muscle strength increased significantly, while the CSAs of the left and right multifidus and psoas major widened as compared with the pre-exercise size. [Conclusion] Spinal stabilization exercise was effective for reducing pain and disability in DDD patients. It was an effective adjunct to aid rehabilitation in these cases. PMID:24764637

  9. A Cross-sectional Study of Correlation of Body Image Anxiety with Social Phobia and Their Association with Depression in the Adolescents from a Rural Area of Sangli District in India

    PubMed Central

    Waghachavare, Vivek Baliram; Quraishi, Sanjay R.; Dhumale, Girish B.; Gore, Alka D.

    2014-01-01

    Background: Prevailing socio-cultural influences lead females to desire a thin body and males a muscular body, especially in adolescents. This results in body image anxiety which may lead to social phobia. Together they can develop depression. The aim was to study the correlation of body image anxiety with social phobia and their association with depression, among adolescents. Methods: This was a cross-sectional study conducted in randomly selected colleges from a rural area of Sangli district Maharashtra, India. Stratified random sampling technique used with sample size 805. Pretested self-administered questionnaire used. Percentage, Chi-square test, binary logistic regression model was used to estimate odds ratio (OR) and its 95% confidence intervals. Results: Of 997 study subjects body image anxiety, social phobia and depression were observed in 232 (23.3%), 193 (19.4%) and 326 (32.7%) participants, respectively. Binary logistic regression showed that body image anxiety (OR = 1.849 [1.22, 2.804]; P = 0.004) and social phobia (OR = 4.575 [2.952-7.09]; P < 0.001) were significant predictors for depression. Conclusions: Body image anxiety and social phobia are linked with the development of depression. This impresses the need for timely counseling and education among adolescents. PMID:25709801

  10. Effect of changes in intra-abdominal pressure on diameter, cross-sectional area, and distensibility of the lower esophageal sphincter of healthy dogs as determined by use of an endoscopic functional luminal imaging probe.

    PubMed

    Mayhew, Philipp D; Pitt, Kathryn A; Steffey, Michele A; Culp, William T N; Kass, Philip H; Marks, Stanley L

    2016-08-01

    OBJECTIVE To evaluate the effect of intra-abdominal pressure (IAP) on morphology and compliance of the lower esophageal sphincter (LES) by use of impedance planimetry in healthy dogs and to quantify the effect of changes in IAP. ANIMALS 7 healthy, purpose-bred sexually intact male hound-cross dogs. PROCEDURES Dogs were anesthetized, and cross-sectional area (CSA), minimal diameter (MD), LES length, LES volume, and distensibility index (DI) of the LES were evaluated by use of an endoscopic functional luminal imaging probe. For each dog, measurements were obtained before (baseline) and after creation of a pneumoperitoneum at an IAP of 4, 8, and 15 mm Hg. Order of the IAPs was determined by use of a randomization software program. RESULTS CSA and MD at 4 and 8 mm Hg were not significantly different from baseline measurements; however, CSA and MD at 15 mm Hg were both significantly greater than baseline measurements. The LES length and LES volume did not differ significantly from baseline measurements at any IAP. The DI differed inconsistently from the baseline measurement but was not substantially affected by IAP. CONCLUSIONS AND CLINICAL RELEVANCE Pneumoperitoneum created with an IAP of 4 or 8 mm Hg did not significantly alter LES morphology in healthy dogs. Pneumoperitoneum at an IAP of 15 mm Hg caused a significant increase in CSA and MD of the LES. Compliance of the LES as measured by the DI was not greatly altered by pneumoperitoneum at an IAP of up to 15 mm Hg. PMID:27463542

  11. Determining physiological cross-sectional area of extensor carpi radialis longus and brevis as a whole and by regions using 3D computer muscle models created from digitized fiber bundle data.

    PubMed

    Ravichandiran, Kajeandra; Ravichandiran, Mayoorendra; Oliver, Michele L; Singh, Karan S; McKee, Nancy H; Agur, Anne M R

    2009-09-01

    Architectural parameters and physiological cross-sectional area (PCSA) are important determinants of muscle function. Extensor carpi radialis longus (ECRL) and brevis (ECRB) are used in muscle transfers; however, their regional architectural differences have not been investigated. The aim of this study is to develop computational algorithms to quantify and compare architectural parameters (fiber bundle length, pennation angle, and volume) and PCSA of ECRL and ECRB. Fiber bundles distributed throughout the volume of ECRL (75+/-20) and ECRB (110+/-30) were digitized in eight formalin embalmed cadaveric specimens. The digitized data was reconstructed in Autodesk Maya with computational algorithms implemented in Python. The mean PCSA and fiber bundle length were significantly different between ECRL and ECRB (p < or = 0.05). Superficial ECRL had significantly longer fiber bundle length than the deep region, whereas the PCSA of superficial ECRB was significantly larger than the deep region. The regional quantification of architectural parameters and PCSA provides a framework for the exploration of partial tendon transfers of ECRL and ECRB.

  12. Lactiferous vessel detection from microscopic cross-sectional images

    NASA Astrophysics Data System (ADS)

    Jariyawatthananon, Jirapath; Cooharojananone, Nagul; Lipikorn, Rajalida

    2014-04-01

    This paper presents the methods to detect and segment lactiferous vessels or rubber latex vessels from gray scale microscopic cross-sectional images using polynomial curve-fitting with maximum and minimum stationary points. Polynomial curve-fitting is used to detect the location of lactiferous vessels from an image of a non-dyed cross-sectional slice which was taken by a digital camera through microscope lens. The lactiferous vessels are then segmented from an image using maximum and minimum stationary points with morphological closing operation. Two species of rubber trees of age between one to two years old are sampled namely, RRIM600 and RRIT251. Two data sets contain 30 microscopic cross-sectional images of one-year old rubber tree's stems from each species are used in the experiments and the results reveal that most of the lactiferous vessel areas can be segmented correctly.

  13. Inclined Bodies of Various Cross Sections at Supersonic Speeds

    NASA Technical Reports Server (NTRS)

    Jorgensen, Leland H.

    1958-01-01

    To aid in assessing effects of cross-sectional shape on body aerodynamics, the forces and moments have been measured for bodies with circular, elliptic, square, and triangular cross sections at Mach numbers 1.98 and 3.88. Results for bodies with noncircular cross sections have been compared with results for bodies of revolution having the same axial distribution of cross-sectional area (and, thus, the same equivalent fineness ratio). Comparisons have been made for bodies of fineness ratios 6 and 10 at angles of attack from 0 deg to about 20 deg and for Reynolds numbers, based on body length, of 4.0 x 10(exp 6) and 6.7 x 10(exp 6). The results of this investigation show that distinct aerodynamic advantages can be obtained by using bodies with noncircular cross sections. At certain angles of bank, bodies with elliptic, square, and triangular cross sections develop considerably greater lift and lift-drag ratios than equivalent bodies of revolution. For bodies with elliptic cross sections, lift and pitching-moment coefficients can be correlated with corresponding coefficients for equivalent circular bodies. It has been found that the ratios of lift and pitching-moment coefficients for an elliptic body to those for an equivalent circular body are practically constant with change in both angle of attack and Mach number. These lift and moment ratios are given very accurately by slender-body theory. As a result of this agreement, the method of NACA Rep. 1048 for computing forces and moments for bodies of revolution has been simply extended to bodies with elliptic cross sections. For the cases considered (elliptic bodies of fineness ratios 6 and 10 having cross-sectional axis ratios of 1.5 and 2), agreement of theory with experiment is very good. As a supplement to the force and moment results, visual studies of the flow over bodies have been made by use of the vapor-screen, sublimation, and white-lead techniques. Photographs from these studies are included in the report.

  14. APPARATUS FOR MEASURING TOTAL NEUTRON CROSS SECTIONS

    DOEpatents

    Cranberg, L.

    1959-10-13

    An apparatus is described for measuring high-resolution total neutron cross sections at high counting rate in the range above 50-kev neutron energy. The pulsed-beam time-of-flight technique is used to identify the neutrons of interest which are produced in the target of an electrostatic accelerator. Energy modulation of the accelerator . makes it possible to make observations at 100 energy points simultaneously. 761O An apparatus is described for monitoring the proton resonance of a liquid which is particulariy useful in the continuous purity analysis of heavy water. A hollow shell with parallel sides defines a meander chamber positioned within a uniform magnetic fieid. The liquid passes through an inlet at the outer edge of the chamber and through a spiral channel to the central region of the chamber where an outlet tube extends into the chamber perpendicular to the magnetic field. The radiofrequency energy for the monitor is coupled to a coil positioned coaxially with the outlet tube at its entrance point within the chamber. The improvement lies in the compact mechanical arrangement of the monitor unit whereby the liquid under analysis is subjected to the same magnetic field in the storage and sensing areas, and the entire unit is shielded from external electrostatic influences.

  15. Skin Diseases: Cross-section of human skin

    MedlinePlus

    Skip Navigation Bar Home Current Issue Past Issues Skin Diseases Cross-section of human skin Past Issues / Fall 2008 Table of Contents For ... Logical Images, Inc. I n the areas of skin health and skin diseases, the NIH's National Institute ...

  16. Actinide cross section program at ORELA

    SciTech Connect

    Dabbs, J. W.T.

    1980-01-01

    The actinide cross section program at ORELA, the Oak Ridge Electron Linear Accelerator, is aimed at obtaining accurate neutron cross sections (primarily fission, capture, and total) for actinide nuclides which occur in fission reactors. Such cross sections, measured as a function of neutron energy over as wide a range of energies as feasible, comprise a data base that permits calculated predictions of the formation and removal of these nuclides in reactors. The present program is funded by the Division of Basic Energy Sciences of DOE, and has components in several divisions at ORNL. For intensively ..cap alpha..-active nuclides, many of the existing fission cross section data have been provided by underground explosions. New measurement techniques, developed at ORELA, now permit linac measurements on fissionable nuclides with alpha half-lives as short as 28 years. Capture and capture-plus-fission measurements utilize scintillation detectors (of capture ..gamma.. rays and fission neutrons) in which pulse shape discrimination plays an important role. Total cross sections can be measured at ORELA on samples of only a few milligrams. A simultaneous program of chemical and isotopic analyses of samples irradiated in EBR-II is in progress to provide benchmarks for the existing differential measurements. These analyses are being studied with updated versions of ORIGEN and with sensitivity determinations. Calculations of the sensitivity to cross section changes of various aspects of the nuclear fuel cycle are also being made. Even in this relatively mature field, many cross sections still require improvements to provide an adequate data base. Examples of recent techniques and measurements are presented. 12 figures, 3 tables.

  17. Coverage of Adequately Iodized Salt Is Suboptimal and Rice Fortification Using Public Distribution Channels Could Reach Low-Income Households: Findings from a Cross-Sectional Survey of Anganwadi Center Catchment Areas in Telangana, India.

    PubMed

    Wirth, James P; Leyvraz, Magali; Sodani, Prahlad R; Aaron, Grant J; Sharma, Narottam D; Woodruff, Bradley A

    2016-01-01

    Food fortification is a cost-effective approach to prevent and control of micronutrient deficiencies in India. A cross-sectional survey of children 0-35 months of age residing in the catchment areas of anganwadi centers in the state of Telangana was conducted to assess the coverage of adequately iodized salt and the potential for rice fortification. Salt samples were collected and tested for iodine concentration using iodometric titration. Information on demographics, household rice consumption, and Telangana's rice sector was collected and interpreted. In households of selected children, 79% of salt samples were found to be adequately iodized. Salt brand and district were significant predictors of inadequately iodized salt. Daily rice consumption among children and women averaged 122 grams and 321 grams per day, respectively. Approximately 28% of households reported consuming rice produced themselves or purchased from a local farmer, 65% purchased rice from a market or shop, 6% got rice from a public distribution system site, and 2% obtained it from a rice mill. In the catchment areas of Telangana's anganwadi centers, there is significant variation in the coverage of adequately iodized salt by district. Future surveys in Telangana should measure the coverage of salt iodization in the general population using quantitative methods. Nonetheless, increasing the adequacy of iodization of smaller salt manufacturers would help achieve universal salt iodization in Telangana. Despite high consumption of rice, our findings suggest that large-scale market-based rice fortification is not feasible in Telangana due to a large proportion of households producing their own rice and highly fragmented rice distribution. Distributing fortified rice via Telangana's public distribution system may be a viable approach to target low-income households, but would only reach a small proportion of the population in Telangana. PMID:27447925

  18. Coverage of Adequately Iodized Salt Is Suboptimal and Rice Fortification Using Public Distribution Channels Could Reach Low-Income Households: Findings from a Cross-Sectional Survey of Anganwadi Center Catchment Areas in Telangana, India

    PubMed Central

    Wirth, James P.; Leyvraz, Magali; Sodani, Prahlad R.; Aaron, Grant J.; Sharma, Narottam D.; Woodruff, Bradley A.

    2016-01-01

    Food fortification is a cost-effective approach to prevent and control of micronutrient deficiencies in India. A cross-sectional survey of children 0–35 months of age residing in the catchment areas of anganwadi centers in the state of Telangana was conducted to assess the coverage of adequately iodized salt and the potential for rice fortification. Salt samples were collected and tested for iodine concentration using iodometric titration. Information on demographics, household rice consumption, and Telangana’s rice sector was collected and interpreted. In households of selected children, 79% of salt samples were found to be adequately iodized. Salt brand and district were significant predictors of inadequately iodized salt. Daily rice consumption among children and women averaged 122 grams and 321 grams per day, respectively. Approximately 28% of households reported consuming rice produced themselves or purchased from a local farmer, 65% purchased rice from a market or shop, 6% got rice from a public distribution system site, and 2% obtained it from a rice mill. In the catchment areas of Telangana’s anganwadi centers, there is significant variation in the coverage of adequately iodized salt by district. Future surveys in Telangana should measure the coverage of salt iodization in the general population using quantitative methods. Nonetheless, increasing the adequacy of iodization of smaller salt manufacturers would help achieve universal salt iodization in Telangana. Despite high consumption of rice, our findings suggest that large-scale market-based rice fortification is not feasible in Telangana due to a large proportion of households producing their own rice and highly fragmented rice distribution. Distributing fortified rice via Telangana’s public distribution system may be a viable approach to target low-income households, but would only reach a small proportion of the population in Telangana. PMID:27447925

  19. Coverage of Adequately Iodized Salt Is Suboptimal and Rice Fortification Using Public Distribution Channels Could Reach Low-Income Households: Findings from a Cross-Sectional Survey of Anganwadi Center Catchment Areas in Telangana, India.

    PubMed

    Wirth, James P; Leyvraz, Magali; Sodani, Prahlad R; Aaron, Grant J; Sharma, Narottam D; Woodruff, Bradley A

    2016-01-01

    Food fortification is a cost-effective approach to prevent and control of micronutrient deficiencies in India. A cross-sectional survey of children 0-35 months of age residing in the catchment areas of anganwadi centers in the state of Telangana was conducted to assess the coverage of adequately iodized salt and the potential for rice fortification. Salt samples were collected and tested for iodine concentration using iodometric titration. Information on demographics, household rice consumption, and Telangana's rice sector was collected and interpreted. In households of selected children, 79% of salt samples were found to be adequately iodized. Salt brand and district were significant predictors of inadequately iodized salt. Daily rice consumption among children and women averaged 122 grams and 321 grams per day, respectively. Approximately 28% of households reported consuming rice produced themselves or purchased from a local farmer, 65% purchased rice from a market or shop, 6% got rice from a public distribution system site, and 2% obtained it from a rice mill. In the catchment areas of Telangana's anganwadi centers, there is significant variation in the coverage of adequately iodized salt by district. Future surveys in Telangana should measure the coverage of salt iodization in the general population using quantitative methods. Nonetheless, increasing the adequacy of iodization of smaller salt manufacturers would help achieve universal salt iodization in Telangana. Despite high consumption of rice, our findings suggest that large-scale market-based rice fortification is not feasible in Telangana due to a large proportion of households producing their own rice and highly fragmented rice distribution. Distributing fortified rice via Telangana's public distribution system may be a viable approach to target low-income households, but would only reach a small proportion of the population in Telangana.

  20. Photodisintegration Cross Section of 241Am

    NASA Astrophysics Data System (ADS)

    Tonchev, A. P.; Hammond, S.; Howell, C. R.; Huibregtse, C.; Hutcheson, A.; Karwowski, H. J.; Kelley, J. H.; Kwan, E.; Rusev, G.; Tornow, W.; Vieira, D. J.; Wilhelmy, J. B.

    2009-03-01

    The photodisintegration cross section of radioactive 241Am has been obtained for the first time using monoenergetic γ-ray beams from the HIγS facility. The induced activity of 240Am produced via the 241Am(γ,n) reaction in the γ-ray energy range from 9.5 to 16 MeV was measured by the activation technique utilizing high resolution HPGe detectors. The 241Am(γ,n) cross section was determined both by measuring the absolute γ-ray flux and by comparison to the 197Au(γ,n) and 58Ni(γ,n) cross section standards. The experimental data for the 241Am(γ,n) reaction in the giant dipole resonance energy region is compared with statistical nuclear-model calculations.

  1. Top differential cross section measurements (Tevatron)

    SciTech Connect

    Jung, Andreas W.

    2012-01-01

    Differential cross sections in the top quark sector measured at the Fermilab Tevatron collider are presented. CDF used 2.7 fb{sup -1} of data and measured the differential cross section as a function of the invariant mass of the t{bar t} system. The measurement shows good agreement with the standard model and furthermore is used to derive limits on the ratio {kappa}/M{sub Pl} for gravitons which decay to top quarks in the Randall-Sundrum model. D0 used 1.0 fb{sup -1} of data to measure the differential cross section as a function of the transverse momentum of the top-quark. The measurement shows a good agreement to the next-to-leading order perturbative QCD prediction and various other standard model predictions.

  2. Algorithmic analysis of quantum radar cross sections

    NASA Astrophysics Data System (ADS)

    Lanzagorta, Marco; Venegas-Andraca, Salvador

    2015-05-01

    Sidelobe structures on classical radar cross section graphs are a consequence of discontinuities in the surface currents. In contrast, quantum radar theory states that sidelobe structures on quantum radar cross section graphs are due to quantum interference. Moreover, it is conjectured that quantum sidelobe structures may be used to detect targets oriented off the specular direction. Because of the high data bandwidth expected from quantum radar, it may be necessary to use sophisticated quantum signal analysis algorithms to determine the presence of stealth targets through the sidelobe structures. In this paper we introduce three potential quantum algorithmic techniques to compute classical and quantum radar cross sections. It is our purpose to develop a computer science-oriented tool for further physical analysis of quantum radar models as well as applications of quantum radar technology in various fields.

  3. The cross section for double Compton scattering

    NASA Technical Reports Server (NTRS)

    Gould, R. J.

    1984-01-01

    Employing elementary methods in nonrelativistic quantum electrodynamics, the cross section for gamma sub 0 + e yields e + gamma + gamma is computed for arbitrary energy in the spectrum of the outgoing photons. The final result is given, differential in the energy of one of these photons, for the case where the incident photon is unpolarized and has energy E sub 0 much less than mc-squared, a polarization sum and angular integration being performed for the final-state photons. The cross section has a simple algebraic form resulting from contributions from the sum of squared direct and exchange amplitudes; interference terms from these amplitudes do not contribute to the angular-integrated cross section.

  4. Total quadruple photoionization cross section of beryllium

    SciTech Connect

    Emmanouilidou, Agapi

    2007-11-15

    In a quasiclassical framework, we formulate the quadruple ionization by single-photon absorption of the Coulomb five-body problem. We present the quadruple photoionization total cross section of the ground state of beryllium for energies up to 620 eV. Our results for energies close to threshold are in agreement with the Wannier threshold law for four-electron escape. In addition, the agreement of our results with a shape formula provides support for the overall shape of our total quadruple cross section. Finally, we find that the photon energy where the maximum of the total photoionization cross section occurs for single, double, triple, and quadruple photoionization of H, He, Li, and Be, respectively, seems to follow a linear relation with the threshold energy for complete breakup of the respective element.

  5. Upper Airway Elasticity Estimation in Pediatric Down Syndrome Sleep Apnea Patients Using Collapsible Tube Theory.

    PubMed

    Subramaniam, Dhananjay Radhakrishnan; Mylavarapu, Goutham; McConnell, Keith; Fleck, Robert J; Shott, Sally R; Amin, Raouf S; Gutmark, Ephraim J

    2016-05-01

    Elasticity of the soft tissues surrounding the upper airway lumen is one of the important factors contributing to upper airway disorders such as snoring and obstructive sleep apnea. The objective of this study is to calculate patient specific elasticity of the pharynx from magnetic resonance (MR) images using a 'tube law', i.e., the relationship between airway cross-sectional area and transmural pressure difference. MR imaging was performed under anesthesia in children with Down syndrome (DS) and obstructive sleep apnea (OSA). An airway segmentation algorithm was employed to evaluate changes in airway cross-sectional area dilated by continuous positive airway pressure (CPAP). A pressure-area relation was used to make localized estimates of airway wall stiffness for each patient. Optimized values of patient specific Young's modulus for tissue in the velopharynx and oropharynx, were estimated from finite element simulations of airway collapse. Patient specific deformation of the airway wall under CPAP was found to exhibit either a non-linear 'hardening' or 'softening' behavior. The localized airway and tissue elasticity were found to increase with increasing severity of OSA. Elasticity based patient phenotyping can potentially assist clinicians in decision making on CPAP and airway or tissue elasticity can supplement well-known clinical measures of OSA severity.

  6. Neutron capture cross section of 136 Xe

    NASA Astrophysics Data System (ADS)

    Daugherty, Sean; Albert, Joshua; Johnson, Tessa; O'Conner, Thomasina; Kaufman, Lisa

    2015-04-01

    136 Xe is an important 0 νββ candidate, studied in experiments such as EXO-200 and, in the future, nEXO. These experiments require a precise study of neutron capture for their background models. The neutron capture cross section of 136 Xe has been measured at the Detector for Advanced Capture Experiments (DANCE) at the Los Alamos Neutron Science Center. A neutron beam ranging from thermal energy to 100 keV was incident on a gas cell filled with isotopically pure 136 Xe . We will discuss the measurement of partial neutron capture cross sections at thermal and first neutron resonance energies along with corresponding capture gamma cascades.

  7. Infrared absorption cross sections of alternative CFCs

    NASA Technical Reports Server (NTRS)

    Clerbaux, Cathy; Colin, Reginald; Simon, Paul C.

    1994-01-01

    Absorption cross sections have obtained in the infrared atmospheric window, between 600 and 1500 cm(exp -1), for 10 alternative hydrohalocarbons: HCFC-22, HCFC-123, HCFC-124, HCFC-141b, HCFC-142b, HCFC-225ca, HCFC-225cb, HFC-125, HFC-134a, and HFC-152a. The measurements were made at three temperatures (287K, 270K and 253K) with a Fourier transform spectrometer operating at 0.03 cm(exp -1) apodized resolution. Integrated cross sections are also derived for use in radiative models to calculate the global warming potentials.

  8. Covariance Evaluation Methodology for Neutron Cross Sections

    SciTech Connect

    Herman,M.; Arcilla, R.; Mattoon, C.M.; Mughabghab, S.F.; Oblozinsky, P.; Pigni, M.; Pritychenko, b.; Songzoni, A.A.

    2008-09-01

    We present the NNDC-BNL methodology for estimating neutron cross section covariances in thermal, resolved resonance, unresolved resonance and fast neutron regions. The three key elements of the methodology are Atlas of Neutron Resonances, nuclear reaction code EMPIRE, and the Bayesian code implementing Kalman filter concept. The covariance data processing, visualization and distribution capabilities are integral components of the NNDC methodology. We illustrate its application on examples including relatively detailed evaluation of covariances for two individual nuclei and massive production of simple covariance estimates for 307 materials. Certain peculiarities regarding evaluation of covariances for resolved resonances and the consistency between resonance parameter uncertainties and thermal cross section uncertainties are also discussed.

  9. Seventy-year-old habitual volleyball players have larger tibial cross-sectional area and may be differentiated from their age-matched peers by the osteogenic index in dynamic performance.

    PubMed

    Rantalainen, T; Linnamo, V; Komi, P V; Selänne, H; Heinonen, A

    2010-07-01

    The osteogenicity of a given exercise may be estimated by calculating an osteogenic index (OI) consisting of magnitude and rate of strain. Volleyball involves repetitive jumping and requires high power output and thus may be expected to be beneficial to bone and performance. The purpose of the present study was to examine if habitual volleyball playing is reflected in OI. Ten elderly habitual volleyball players [age 69.9 (SD 4.4) years] and ten matched controls volunteered [age 69.7 (4.2) years] as subjects. Distal tibia (d), tibial mid-shaft (50) and femoral neck (FN) bone characteristics were measured using pQCT and DXA. To estimate skeletal rigidity, cross-sectional area (ToA(50)), and compressive (BSI(d)) and bending strength indices (SSImax(50)) were calculated. Maximal performance was assessed with eccentric ankle plantar flexion, isometric leg press and countermovement jump (CMJ). A fast Fourier transform (FFT) was calculated from the acceleration of the center of mass during the CMJ. Maximal acceleration (MAG) and mean magnitude frequency (MMF) were selected to represent the constituents of OI. OI was calculated as the sum of the products of magnitudes and corresponding frequencies. Volleyball players had 7% larger ToA(50) and 37% higher power in CMJ, 15% higher MAG and 36% higher OI (P or= 0.646). In conclusion, habitual volleyball players may be differentiated from their matched peers by their dynamic jumping performance, and the differences are reflected in the magnitude but not rate of loading.

  10. Testing (Validating?) Cross Sections with ICSBEP Benchmarks

    SciTech Connect

    Kahler, Albert C. III

    2012-06-28

    We discuss how to use critical benchmarks from the International Handbook of Evaluated Criticality Safety Benchmark Experiments to determine the applicability of specific cross sections to the end-user's problem of interest. Particular attention is paid to making sure the selected suite of benchmarks includes the user's range of applicability (ROA).

  11. Neutron capture cross section of Am241

    NASA Astrophysics Data System (ADS)

    Jandel, M.; Bredeweg, T. A.; Bond, E. M.; Chadwick, M. B.; Clement, R. R.; Couture, A.; O'Donnell, J. M.; Haight, R. C.; Kawano, T.; Reifarth, R.; Rundberg, R. S.; Ullmann, J. L.; Vieira, D. J.; Wilhelmy, J. B.; Wouters, J. M.; Agvaanluvsan, U.; Parker, W. E.; Wu, C. Y.; Becker, J. A.

    2008-09-01

    The neutron capture cross section of Am241 for incident neutrons from 0.02 eV to 320 keV has been measured with the detector for advanced neutron capture experiments (DANCE) at the Los Alamos Neutron Science Center. The thermal neutron capture cross section was determined to be 665±33 b. Our result is in good agreement with other recent measurements. Resonance parameters for En<12 eV were obtained using an R-matrix fit to the measured cross section. The results are compared with values from the ENDF/B-VII.0, Mughabghab, JENDL-3.3, and JEFF-3.1 evaluations. Γn neutron widths for the first three resonances are systematically larger by 5-15% than the ENDF/B-VII.0 values. The resonance integral above 0.5 eV was determined to be 1553±7 b. Cross sections in the resolved and unresolved energy regions above 12 eV were calculated using the Hauser-Feshbach theory incorporating the width-fluctuation correction of Moldauer. The calculated results agree well with the measured data, and the extracted averaged resonance parameters in the unresolved resonance region are consistent with those for the resolved resonances.

  12. Cross Sections From Scalar Field Theory

    NASA Technical Reports Server (NTRS)

    Norbury, John W.; Dick, Frank; Norman, Ryan B.; Nasto, Rachel

    2008-01-01

    A one pion exchange scalar model is used to calculate differential and total cross sections for pion production through nucleon- nucleon collisions. The collisions involve intermediate delta particle production and decay to nucleons and a pion. The model provides the basic theoretical framework for scalar field theory and can be applied to particle production processes where the effects of spin can be neglected.

  13. Cross sections relevant to gamma ray astronomy

    NASA Technical Reports Server (NTRS)

    Dyer, P.; Bodansky, D.; Maxson, D. R.

    1978-01-01

    Gamma-ray production cross sections were measured for protons and alpha particles incident on targets consisting of nuclei of high cosmic abundance: C-12, N-14, O-16, Ne-20, Mg-24, Si-28 and Fe-56. Solid or gaseous targets were bombarded by monoenergetic beams of protons and alpha particles, and gamma rays were detected by two Ge(Li) detectors. The proton energy for each target was varied from threshold to about 24 MeV (lab); for alphas the range was from threshold to about 27 MeV. For most transitions, it was possible to measure the total cross section by placing the detectors at 30.5 deg and 109.9 deg where the fourth-order Legendre polynomial is zero. For the case of the 16O (E sub gamma = 6.13 MeV, multipolarity E3) cross sections, yields were measured at four angles. Absolute cross sections were obtained by integrating the beam current and by measuring target thicknesses and detector efficiencies. The Ge(Li) detector resolution was a few keV (although the peak widths were greater, due to Doppler broadening).

  14. Neutron Capture Cross Sections for Radioactive Nuclei

    NASA Astrophysics Data System (ADS)

    Tonchev, Anton; Bedrossian, Peter; Escher, Jutta; Scielzo, Nicholas

    2015-10-01

    Accurate neutron-capture cross sections for radioactive nuclei near or far away from the line of beta stability are crucial for understanding the nucleosynthesis of heavy elements. However, neutron-capture cross sections for short-lived radionuclides are difficult to measure due to the fact that the measurements require both highly radioactive samples and intense neutron sources. Essential ingredients for describing the γ decays following neutron capture are the γ-ray strength function and level densities. We will compare different indirect approaches for obtaining observables that can constrain Hauser-Feshbach statistical model calculations of capture cross sections. Specifically, we will consider photon scattering, transfer reactions, and beta-delayed neutron emission. Challenges that exist on the path to obtaining neutron-capture cross sections for reactions on isotopes far from stability will be discussed. This work was performed under the auspices of US DOE by LLNL under contract DE-AC52-07NA27344. Funding was provided via the LDRD-ERD-069 project.

  15. Propagation of sound waves in tubes of noncircular cross section

    NASA Technical Reports Server (NTRS)

    Richards, W. B.

    1986-01-01

    Plane-acoustic-wave propagation in small tubes with a cross section in the shape of a flattened oval is described. Theoretical descriptions of a plane wave propagating in a tube with circular cross section and between a pair of infinite parallel plates, including viscous and thermal damping, are expressed in similar form. For a wide range of useful duct sizes, the propagation constant (whose real and imaginary parts are the amplitude attenuation rate and the wave number, respectively) is very nearly the same function of frequency for both cases if the radius of the circular tube is the same as the distance between the parallel plates. This suggests that either a circular-cross-section model or a flat-plate model can be used to calculate wave propagation in flat-oval tubing, or any other shape tubing, if its size is expressed in terms of an equivalent radius, given by g = 2 x (cross-sectional area)/(length of perimeter). Measurements of the frequency response of two sections of flat-oval tubing agree with calculations based on this idea. Flat-plate formulas are derived, the use of transmission-line matrices for calculations of plane waves in compound systems of ducts is described, and examples of computer programs written to carry out the calculations are shown.

  16. Correlates of smoking susceptibility among adolescents in a peri-urban area of Nepal: a population-based cross-sectional study in the Jhaukhel-Duwakot Health Demographic Surveillance Site

    PubMed Central

    Aryal, Umesh R.; Petzold, Max; Bondjers, Göran; Krettek, Alexandra

    2014-01-01

    Background Susceptibility to smoking is defined as an absence of firm commitment not to smoke in the future or when offered a cigarette by best friends. Susceptibility begins in adolescence and is the first step in the transition to becoming an established smoker. Many scholars have hypothesized and studied whether psychosocial risk factors play a crucial role in preventing adolescent susceptibility to smoking or discourage susceptible adolescents from becoming established smokers. Our study examined sociodemographic and family and childhood environmental factors associated with smoking susceptibility among adolescents in a peri-urban area of Nepal. Design We conducted a population-based cross-sectional study during October–November 2011 in the Jhaukhel-Duwakot Health Demographic Surveillance Site (JD-HDSS) located in a peri-urban area near Kathmandu, the capital city of Nepal, where tobacco products are easily available. Trained local enumerators conducted face-to-face interviews with 352 respondents aged 14–16. We used stepwise logistic regression to assess sociodemographic and family and childhood environmental factors associated with smoking susceptibility. Results The percentage of smoking susceptibility among respondents was 49.70% (95% CI: 44.49; 54.93). Multivariable analysis demonstrated that smoking susceptibility was associated with smoking by exposure of adolescents to pro-tobacco advertisements (AOR [adjusted odds ratio] =2.49; 95% CI: 1.46–4.24), the teacher (2.45; 1.28–4.68), adolescents attending concerts/picnics (2.14; 1.13–4.04), and smoking by other family members/relatives (1.76; 1.05–2.95). Conclusions Smoking susceptible adolescents are prevalent in the JD-HDSS, a peri-urban community of Nepal. Several family and childhood environmental factors increased susceptibility to smoking among Nepalese non-smoking adolescents. Therefore, intervention efforts need to be focused on family and childhood environmental factors with emphasis on

  17. Absolute np and pp Cross Section Determinations Aimed At Improving The Standard For Cross Section Measurements

    SciTech Connect

    Laptev, A. B.; Haight, R. C.; Tovesson, F.; Arndt, R. A.; Briscoe, W. J.; Paris, M. W.; Strakovsky, I. I.; Workman, R. L.

    2011-06-01

    Purpose of present research is a keeping improvement of the standard for cross section measurements of neutron-induced reactions. The cross sections for np and pp scattering below 1 GeV are determined based on partial-wave analyses (PWAs) of nucleon-nucleon scattering data. These cross sections are compared with the most recent ENDF/B-VII.0 and JENDL-4.0 data files, and the Nijmegen PWA. Also a comparison of evaluated data with recent experimental data was made to check a quality of evaluation. Excellent agreement was found between the new experimental data and our PWA predictions.

  18. Absolute np and pp cross section determinations aimed at improving the standard for cross section measurements

    SciTech Connect

    Laptev, Alexander B; Haight, Robert C; Tovesson, Fredrik; Arndt, Richard A; Briscoe, William J; Paris, Mark W; Strakovsky, Igor I; Workman, Ron L

    2010-01-01

    Purpose of present research is a keeping improvement of the standard for cross section measurements of neutron-induced reactions. The cross sections for np and pp scattering below 1000 MeV are determined based on partial-wave analyses (PW As) of nucleon-nucleon scattering data. These cross sections are compared with the most recent ENDF/B-V11.0 and JENDL-4.0 data files, and the Nijmegen PWA. Also a comparison of evaluated data with recent experimental data was made to check a quality of evaluation. Excellent agreement was found between the new experimental data and our PWA predictions.

  19. Inclusive jet cross section at the Tevatron

    SciTech Connect

    1998-01-01

    The authors report preliminary measurements of the central inclusive jet cross section at 1.8 TeV by the D0 and the CDF collaborations at the p{anti p} Fermilab collider. They are based on an integrated luminosity of 92 and 87 pb-1, respectively. The cross sections are measured as a function of jet transverse energy in the pseudorapidity interval 0.1 < 1,711 < 0.7 (CDF), and the two pseudorapidity ranges 1,711 < 0.5 and 0.1 < Inj < 0.7 (D0). D0 reports good agreement with the Next-to-Leading Order QCD predictions currently available. CDF observes an excess above 200 GeV, which can be accommodated with a modification in the gluon distribution function at high x.

  20. Cross sections required for FMIT dosimetry

    SciTech Connect

    Gold, R.; McElroy, W.N.; Lippincott, E.P.; Mann, F.M.; Oberg, D.L.; Roberts, J.H.; Ruddy, F.H.

    1980-05-02

    The Fusion Materials Irradiation Test (FMIT) facility, currently under construction, is designed to produce a high flux of high energy neutrons for irradiation effects experiments on fusion reactor materials. Characterization of the flux-fluence-spectrum in this rapidly varying neutron field requires adaptation and extension of currently available dosimetry techniques. This characterization will be carried out by a combination of active, passive, and calculational dosimetry. The goal is to provide the experimenter with accurate neutron flux-fluence-spectra at all positions in the test cell. Plans have been completed for a number of experimental dosimetry stations and provision for these facilities has been incorporated into the FMIT design. Overall needs of the FMIT irradiation damage program delineate goal accuracies for dosimetry that, in turn, create new requirements for high energy neutron cross section data. Recommendations based on these needs have been derived for required cross section data and accuracies.

  1. Proton Pair Production Cross Sections at BESIII

    NASA Astrophysics Data System (ADS)

    Zhou, Xiaorong

    Using data samples collected with the BESIII detector at the BEPCII collider, the Born cross section of e + e - to pbar{p} at 12 center-of-mass energies from 2232.4 to 3671.0 MeV is provided. The corresponding effective electromagnetic form factor of the proton is deduced under the assumption that the electric and magnetic form factors are equal. In addition, the ratio of electric to magnetic form factors are extracted for the data samples with larger statistics. The measured cross sections are in agreement with recent results from BaBar, improving the overall uncertainty by about 30%. The |GE/GM| ratios are close to unity and consistent with BaBar results in the same q2 region.

  2. Rotational averaging of multiphoton absorption cross sections

    SciTech Connect

    Friese, Daniel H. Beerepoot, Maarten T. P.; Ruud, Kenneth

    2014-11-28

    Rotational averaging of tensors is a crucial step in the calculation of molecular properties in isotropic media. We present a scheme for the rotational averaging of multiphoton absorption cross sections. We extend existing literature on rotational averaging to even-rank tensors of arbitrary order and derive equations that require only the number of photons as input. In particular, we derive the first explicit expressions for the rotational average of five-, six-, and seven-photon absorption cross sections. This work is one of the required steps in making the calculation of these higher-order absorption properties possible. The results can be applied to any even-rank tensor provided linearly polarized light is used.

  3. Inclusive jet cross section measurement at CDF

    SciTech Connect

    Pagliarone, C.

    1996-08-01

    The CDF Collaboration has measured the inclusive jet cross section using 1992-93 collider data at 1.8 TeV. The CDF measurement is in very good agreement with NLO QCD predictions for transverse energies (E{sub T}) below 200 GeV. However, it is systematically higher than NLO QCD predictions for E{sub T} above 200 GeV.

  4. {sup 231}Pa photofission cross section

    SciTech Connect

    Soldatov, A.S.; Rudnikov, V.E.; Smirenkin, G.N.

    1995-12-01

    The measurements of the {sup 231}Pa yield and cross section photofission in the energy range 7-9 MeV are presented. These measurements are a continuation of similar measurements performed for the {gamma}-ray energy range 4.8-7 MeV. The entire collection of experimental data which combine the results obtained in the present work and in Ref. 1 was analyzed.

  5. Absolute photoionization cross sections of atomic oxygen

    NASA Technical Reports Server (NTRS)

    Samson, J. A. R.; Pareek, P. N.

    1985-01-01

    The absolute values of photoionization cross sections of atomic oxygen were measured from the ionization threshold to 120 A. An auto-ionizing resonance belonging to the 2S2P4(4P)3P(3Do, 3So) transition was observed at 479.43 A and another line at 389.97 A. The experimental data is in excellent agreement with rigorous close-coupling calculations that include electron correlations in both the initial and final states.

  6. Absolute photoionization cross sections of atomic oxygen

    NASA Technical Reports Server (NTRS)

    Samson, J. A. R.; Pareek, P. N.

    1982-01-01

    The absolute values of photoionization cross sections of atomic oxygen were measured from the ionization threshold to 120 A. An auto-ionizing resonance belonging to the 2S2P4(4P)3P(3Do, 3So) transition was observed at 479.43 A and another line at 389.97 A. The experimental data is in excellent agreement with rigorous close-coupling calculations that include electron correlations in both the initial and final states.

  7. Fusion cross sections measurements with MUSIC

    NASA Astrophysics Data System (ADS)

    Carnelli, P. F. F.; Fernández Niello, J. O.; Almaraz-Calderon, S.; Rehm, K. E.; Albers, M.; Digiovine, B.; Esbensen, H.; Henderson, D.; Jiang, C. L.; Nusair, O.; Palchan-Hazan, T.; Pardo, R. C.; Ugalde, C.; Paul, M.; Alcorta, M.; Bertone, P. F.; Lai, J.; Marley, S. T.

    2014-09-01

    The interaction between exotic nuclei plays an important role for understanding the reaction mechanism of the fusion processes as well as for the energy production in stars. With the advent of radioactive beams new frontiers for fusion reaction studies have become accessible. We have performed the first measurements of the total fusion cross sections in the systems 10 , 14 , 15C + 12C using a newly developed active target-detector system (MUSIC). Comparison of the obtained cross sections with theoretical predictions show a good agreement in the energy region accessible with existing radioactive beams. This type of comparison allows us to calibrate the calculations for cases that cannot be studied in the laboratory with the current experimental capabilities. The high efficiency of this active detector system will allow future measurements with even more neutron-rich isotopes. The interaction between exotic nuclei plays an important role for understanding the reaction mechanism of the fusion processes as well as for the energy production in stars. With the advent of radioactive beams new frontiers for fusion reaction studies have become accessible. We have performed the first measurements of the total fusion cross sections in the systems 10 , 14 , 15C + 12C using a newly developed active target-detector system (MUSIC). Comparison of the obtained cross sections with theoretical predictions show a good agreement in the energy region accessible with existing radioactive beams. This type of comparison allows us to calibrate the calculations for cases that cannot be studied in the laboratory with the current experimental capabilities. The high efficiency of this active detector system will allow future measurements with even more neutron-rich isotopes. This work is supported by the U.S. DOE Office of Nuclear Physics under Contract No. DE-AC02-06CH11357 and the Universidad Nacional de San Martin, Argentina, Grant SJ10/39.

  8. How to Calculate Colourful Cross Sections Efficiently

    SciTech Connect

    Gleisberg, Tanju; Hoeche, Stefan; Krauss, Frank

    2008-09-03

    Different methods for the calculation of cross sections with many QCD particles are compared. To this end, CSW vertex rules, Berends-Giele recursion and Feynman-diagram based techniques are implemented as well as various methods for the treatment of colours and phase space integration. We find that typically there is only a small window of jet multiplicities, where the CSW technique has efficiencies comparable or better than both of the other two methods.

  9. Nonperturbative corrections in resummed cross sections

    NASA Astrophysics Data System (ADS)

    Korchemsky, Gregory P.; Sterman, George

    1995-02-01

    We show that the resummation of large perturbative corrections in QCD leads to ambiguities in high energy cross sections that are suppressed by powers of large momentum scales. These ambiguities are caused by infrared renormalons, which are a general feature of resummed hardscattering functions in perturbative QCD, even though these functions are infrared safe order-by-order in perturbation theory. As in the case of the operator product expansion, the contributions of infrared renormalons to coefficient functions may be absorbed into the definition of higher-dimensional operators, which induce nonperturbative corrections that are power-suppressed at high energies. The strength of the suppression is determined by the location of the dominant infrared renormalon, which may be identified explicitly in the resummed series. In contrast to the operator product expansion, however, the relevant operators in factorized hadron-hadron scattering and jet cross sections are generally nonlocal in QCD, although they may be expressed as local operators in an effective theory for eikonalized quarks. In this context, we verify and interpret the presence of 1 / Q corrections to the inclusive Drell-Yan cross section with Q the pair mass. In a similar manner, we find exp (- b2 In Q) corrections in the impact parameter space of the transverse momentum distributions of the Drell-Yan process and e +6 - annihilation. We also show that the dominant nonperturbative corrections to cone-based jet cross sections behave as 1 /( Qδ), with δ the opening angle of the jet and Q the center of mass energy.

  10. KLOE results on hadronic cross section

    NASA Astrophysics Data System (ADS)

    Mandaglio, Giuseppe; Ambrosino, F.; Antonelli, A.; Antonelli, M.; Archilli, F.; Balwierz, I.; Bencivenni, G.; Bini, C.; Bloise, C; . Bocchetta, S.; Bossi, F.; Branchini, P.; Capon, G.; Capussela, T.; Ceradini, F.; Ciambrone, P.; Czerwiński, E.; De Lucia, E.; De Santis, A.; De Simone, P.; De Zorzi, G.; Denig, A.; Di Domenico, A.; Di Donato, C.; Di Micco, B.; Dreucci, M.; Felici, G.; Fiore, S.; Franzini, P.; Gatti, C.; Gauzzi, P.; Giovannella, S.; Graziani, E.; Jacewicz, M.; Kluge, W.; Lee-Franzini, J.; Lukin, P.; Martemianov, M.; Martini, M.; Massarotti, P.; Meola, S.; Miscetti, S.; Morello, G.; Moulson, M.; Müller, S; . Napolitano, M.; Nguyen, F.; Palutan, M.; Passeri, A.; Patera, V.; Prado Longhi, I.; Santangelo, P.; Sciascia, B.; Silarski, M.; Spadaro, T.; Taccini, C.; Tortora, L.; Venanzoni, G.; Versaci, R.; Xu, G.; Zdebik, J.; Babusci, D.; Badoni, D.; Bocci, V.; Budano, A.; Bulychjev, S. A; .; Caldeira Balkeståhl, L.; Campana, P.; Dané, E.; De Robertis, G.; Domenici, D.; Erriquez, O.; Fanizzi, G.; Giardina, G.; Gonnella, F.; Happacher, F.; Höistad, B.; Iafolla, L.; Iarocci, E.; Johansson, T.; Kowalewska, A.; Kulikov, V.; Kupsc, A.; Loddo, F.; Mandaglio, G.; Mascolo, M.; Matsyuk, M.; Messi, R.; Moricciani, D.; Ranieri, A.; Redmer, C. F.; Sarra, I.; Schioppa, M.; Sciubba, A.; Wiślicki, W.; Wolke, M.; KLOE/KLOE-2 Collaborations

    2012-03-01

    The KLOE experiment at the phi - factory DAΦNE is the first to have exploited Initial State Radiation (ISR) to precisely determine the e+e- → π+π-(γ) cross section below 1 GeV, representing the 70% of the leading order contribution to the muon anomaly. The leading order contribution ahloμ is presently the main source of uncertainty in the theoretical evaluation of the muon anomaly, and it can be evaluated by dispersion integral using the experimental measurement of hadronic cross section. A persistent discrepancy of about 3 σ between standard model (SM) prediction and experimental measurements of the muon anomalous magnetic moment has been up to now observed. The KLOE collaboration published two measurements of the π+π- cross section with the photon in the initial state emitted at small polar angle in Phys. Lett. B vol. 606 pg. 12 and vol. 670 pg. 285, and an independent measurement with the photon emitted at large polar angle in Phys. Lett. B vol. 700 pg. 102. These measurements were normalized to the DAΦNE luminosity. Recently, a new analysis deriving the pion form factor directly from measuring the bin-by-bin π+πγ and μ+μγ final states ratio has been performed. In this paper, the preliminary results of this new measurement and the comparison to the previous published ones, the impact on the evaluation of the hadronic contribution to the muon anomaly, the preliminary μ+μγ cross section measurement and the comparison with the PHOKHARA-MC prediction are presented.

  11. Quality Quantification of Evaluated Cross Section Covariances

    SciTech Connect

    Varet, S.; Dossantos-Uzarralde, P.

    2015-01-15

    Presently, several methods are used to estimate the covariance matrix of evaluated nuclear cross sections. Because the resulting covariance matrices can be different according to the method used and according to the assumptions of the method, we propose a general and objective approach to quantify the quality of the covariance estimation for evaluated cross sections. The first step consists in defining an objective criterion. The second step is computation of the criterion. In this paper the Kullback-Leibler distance is proposed for the quality quantification of a covariance matrix estimation and its inverse. It is based on the distance to the true covariance matrix. A method based on the bootstrap is presented for the estimation of this criterion, which can be applied with most methods for covariance matrix estimation and without the knowledge of the true covariance matrix. The full approach is illustrated on the {sup 85}Rb nucleus evaluations and the results are then used for a discussion on scoring and Monte Carlo approaches for covariance matrix estimation of the cross section evaluations.

  12. 35. Photograph of a line drawing. 'CROSS SECTION OF PART ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    35. Photograph of a line drawing. 'CROSS SECTION OF PART III, SECTION 1, EQUIPMENT LAYOUT, BUILDINGS E-1 TO E-10 INCL., WASHING, MANUFACTURING AREA, PLANT 'B'.' From the U.S. Army Corps of Engineers. Industrial Facilities Inventory, Holston Ordnance Works, Kingsport, Tennessee. Plant B, Parts II, III. (Nashville, TN: Office of the District Engineer, 1944). - Holston Army Ammunition Plant, RDX-and-Composition-B Manufacturing Line 9, Kingsport, Sullivan County, TN

  13. 42. Photograph of a line drawing. 'CROSS SECTION AND PLAN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    42. Photograph of a line drawing. 'CROSS SECTION AND PLAN LAYOUT OF PART I, SECTION 8, BUILDINGS NO. H-1 TO H-10 INCL., GRINDING, MANUFACTURING AREA, PLANT B AS OF 4-24-44.' From the U.S. Army Corps of Engineers. Industrial Facilities Inventory, Holston Ordnance Works, Kingsport, Tennessee. Plant B, Parts II, III. (NashVille, TN: Office of the District Engineer, 1944). - Holston Army Ammunition Plant, RDX-and-Composition-B Manufacturing Line 9, Kingsport, Sullivan County, TN

  14. 34. Photograph of a line drawing. 'CROSS SECTION AND PLAN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    34. Photograph of a line drawing. 'CROSS SECTION AND PLAN LAYOUT OF PART I, SECTION B, BUILDINGS NO. E-1 TO E-10 INCL., WASHING, MANUFACTURING AREA, PLANT B AS OF 4-24-44.' From the U.S. Army Corps of Engineers. Industrial Facilities Inventory, Holston Ordnance Works, Kingsport, Tennessee. Plant B, Parts II, III. (Nashville, TN: Office of the District Engineer, 1944). - Holston Army Ammunition Plant, RDX-and-Composition-B Manufacturing Line 9, Kingsport, Sullivan County, TN

  15. Differential collision cross-sections for atomic oxygen

    NASA Technical Reports Server (NTRS)

    Torr, Douglas G.

    1991-01-01

    Differential collision cross-sections of O on N2 and other gases were measured to understand vehicle-environmental contamination effects in orbit. The following subject areas are also covered: groundbased scientific observations of rocket releases during NICARE-1; data compression study for the UVI; science priorities for UV imaging in the mid-1990's; and assessment of optimizations possible in UV imaging systems.

  16. 30. Photograph of a line drawing. 'CROSS SECTION OF PART ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    30. Photograph of a line drawing. 'CROSS SECTION OF PART III, SECTION 1, EQUIPMENT LAYOUT, BUILDINGS D-1 TO D-10 INCL., NITRATION, MANUFACTURING AREA, PLANT 'B'.' From U.S. Army Corps of Engineers. Industrial Facilities Inventory, Holston Ordnance Works, Kingsport, Tennessee. Plant B, Parts II, III. (Nashville, TN: Office of the District Engineer, 1944). - Holston Army Ammunition Plant, RDX-and-Composition-B Manufacturing Line 9, Kingsport, Sullivan County, TN

  17. 29. Photograph of a line drawing. 'CROSS SECTION AND PLAN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    29. Photograph of a line drawing. 'CROSS SECTION AND PLAN LAYOUT OF PART I, SECTION 8, BUILDINGS NO. D-1 TO D-10 INCL., NITRATION, MANUFACTURING AREA, PLANT B AS OF 4-24-44.' From the U.S. Army Corps of Engineers. Industrial Facilities Inventory, Holston Ordnance Works, Kingsport, Tennessee. Plant B, Parts II, III. (Nashville, TN: Office of the District Engineer, 1944). - Holston Army Ammunition Plant, RDX-and-Composition-B Manufacturing Line 9, Kingsport, Sullivan County, TN

  18. A Subject-Specific Acoustic Model of the Upper Airway for Snoring Sounds Generation

    PubMed Central

    Saha, Shumit; Bradley, T. Douglas; Taheri, Mahsa; Moussavi, Zahra; Yadollahi, Azadeh

    2016-01-01

    Monitoring variations in the upper airway narrowing during sleep is invasive and expensive. Since snoring sounds are generated by air turbulence and vibrations of the upper airway due to its narrowing; snoring sounds may be used as a non-invasive technique to assess upper airway narrowing. Our goal was to develop a subject-specific acoustic model of the upper airway to investigate the impacts of upper airway anatomy, e.g. length, wall thickness and cross-sectional area, on snoring sounds features. To have a subject-specific model for snoring generation, we used measurements of the upper airway length, cross-sectional area and wall thickness from every individual to develop the model. To validate the proposed model, in 20 male individuals, intensity and resonant frequencies of modeled snoring sounds were compared with those measured from recorded snoring sounds during sleep. Based on both modeled and measured results, we found the only factor that may positively and significantly contribute to snoring intensity was narrowing in the upper airway. Furthermore, measured resonant frequencies of snoring were inversely correlated with the upper airway length, which is a risk factor for upper airway collapsibility. These results encourage the use of snoring sounds analysis to assess the upper airway anatomy during sleep. PMID:27210576

  19. Averaging cross section data so we can fit it

    SciTech Connect

    Brown, D.

    2014-10-23

    The 56Fe cross section we are interested in have a lot of fluctuations. We would like to fit the average of the cross section with cross sections calculated within EMPIRE. EMPIRE is a Hauser-Feshbach theory based nuclear reaction code, requires cross sections to be smoothed using a Lorentzian profile. The plan is to fit EMPIRE to these cross sections in the fast region (say above 500 keV).

  20. Infrared absorption cross sections for trifluoromethane

    NASA Astrophysics Data System (ADS)

    Harrison, Jeremy J.

    2013-11-01

    High-resolution infrared absorption cross sections for trifluoromethane have been determined over the range 950-1500 cm-1 from spectra recorded using a high-resolution FTIR spectrometer (Bruker IFS 125HR) and a 26-cm-pathlength cell. Spectra of trifluoromethane/dry synthetic air mixtures were recorded at 0.015 cm-1 resolution (calculated as 0.9/MOPD) at a number of temperatures and pressures (23-762 Torr and 188-294 K) appropriate for atmospheric conditions. Intensities were calibrated using composite trifluoromethane spectra taken from the Pacific Northwest National Laboratory (PNNL) IR database.

  1. Multicollinearity in cross-sectional regressions

    NASA Astrophysics Data System (ADS)

    Lauridsen, Jørgen; Mur, Jesùs

    2006-10-01

    The paper examines robustness of results from cross-sectional regression paying attention to the impact of multicollinearity. It is well known that the reliability of estimators (least-squares or maximum-likelihood) gets worse as the linear relationships between the regressors become more acute. We resolve the discussion in a spatial context, looking closely into the behaviour shown, under several unfavourable conditions, by the most outstanding misspecification tests when collinear variables are added to the regression. A Monte Carlo simulation is performed. The conclusions point to the fact that these statistics react in different ways to the problems posed.

  2. The calculation of radar cross sections

    NASA Astrophysics Data System (ADS)

    Pizer, R.

    1980-04-01

    The FORTRAN program CHAOS, used for calculating cross sections is described including the physical approximations used to simplify Maxwell's equations. The scattering bodies are extended to both open and closed surfaces. The numerical methods used are supplied. The problems of wire junctions, of finite conductivity and the attaching of lumped loads to the structure are considered. Techniques for dealing with bodies having rotational or left-right symmetries are examined as well as the sparse matrix approximation and the complex frequency version of CHAOS. The formula used to calculate the impedance matrix elements, and the conventions adopted concerning coordinate systems and polarization are included.

  3. Three Dimensional Cross-Sectional Properties From Bone Densitometry

    NASA Technical Reports Server (NTRS)

    Cleek, Tammy M.; Whalen, Robert T.; Dalton, Bonnie P. (Technical Monitor)

    2001-01-01

    Bone densitometry has previously been used to obtain cross-sectional properties of bone in a single scan plane. Using three non-coplanar scans, we have extended the method to obtain the principal area Moments of inertia and orientations of the principal axes at each cross-section along the length of the scan. Various 5 aluminum phantoms were used to examine scanner characteristics to develop the highest accuracy possible for in vitro non-invasive analysis of mass distribution. Factors considered included X-ray photon energy, initial scan orientation, the included angle of the 3 scans, and Imin/Imax ratios. Principal moments of inertia were accurate to within 3.1% and principal angles were within 1 deg. of the expected value for phantoms scanned with included angles of 60 deg. and 90 deg. at the higher X-ray photon energy. Low standard deviations in error also 10 indicate high precision of calculated measurements with these included angles. Accuracy and precision decreased slightly when the included angle was reduced to 30 deg. The method was then successfully applied to a pair of excised cadaveric tibiae. The accuracy and insensitivity of the algorithms to cross-sectional shape and changing isotropy (Imin/Imax) values when various included angles are used make this technique viable for future in vivo studies.

  4. Evaluation of discrepancies in assembly cross-section generator codes

    SciTech Connect

    Fisher, J.R.; Grow, R.L.; Rapp, J.S.; Smolinske, K.M.; Mint, L.S. )

    1990-02-01

    The capabilities of utility reactor analysis technical staffs have increased significantly over the past five to ten years. Utilities utilize different cross section generators (EPRI-CELL, CPM, CASMO), different versions of these generators and different libraries in the generators, to produce input to different nodal codes. Phase I of this project utilized available data from utility calculations to identify the areas of differences in calculated results and to make an initial assessment of the potential impact and/or consequence of these differences. Phase II of this project investigated these differences via a consortium of utilities performing calculations for pin cells and multi-pin cells using controlled input data and options. The Phase II goal was to quantify differences and to determine if the differences were due to cross section library, cross section code methodology or the procedure for utilizing a code. The Phase III goal was to investigate the significant differences from Phase II in an assembly environment to determine if the differences became smaller, larger or remained the same in the assembly environment. The Phase III assembly calculations were performed by the same group of utilities as Phase II and the cases used controlled input and code vendor input option recommendations. 10 figs., 31 tabs.

  5. Summary of the Workshop on Neutron Cross Section Covariances

    SciTech Connect

    Smith, Donald L.

    2008-12-15

    A Workshop on Neutron Cross Section Covariances was held from June 24-27, 2008, in Port Jefferson, New York. This Workshop was organized by the National Nuclear Data Center, Brookhaven National Laboratory, to provide a forum for reporting on the status of the growing field of neutron cross section covariances for applications and for discussing future directions of the work in this field. The Workshop focused on the following four major topical areas: covariance methodology, recent covariance evaluations, covariance applications, and user perspectives. Attention was given to the entire spectrum of neutron cross section covariance concerns ranging from light nuclei to the actinides, and from the thermal energy region to 20 MeV. The papers presented at this conference explored topics ranging from fundamental nuclear physics concerns to very specific applications in advanced reactor design and nuclear criticality safety. This paper provides a summary of this workshop. Brief comments on the highlights of each Workshop contribution are provided. In addition, a perspective on the achievements and shortcomings of the Workshop as well as on the future direction of research in this field is offered.

  6. Hydraulic geometry of river cross sections; theory of minimum variance

    USGS Publications Warehouse

    Williams, Garnett P.

    1978-01-01

    This study deals with the rates at which mean velocity, mean depth, and water-surface width increase with water discharge at a cross section on an alluvial stream. Such relations often follow power laws, the exponents in which are called hydraulic exponents. The Langbein (1964) minimum-variance theory is examined in regard to its validity and its ability to predict observed hydraulic exponents. The variables used with the theory were velocity, depth, width, bed shear stress, friction factor, slope (energy gradient), and stream power. Slope is often constant, in which case only velocity, depth, width, shear and friction factor need be considered. The theory was tested against a wide range of field data from various geographic areas of the United States. The original theory was intended to produce only the average hydraulic exponents for a group of cross sections in a similar type of geologic or hydraulic environment. The theory does predict these average exponents with a reasonable degree of accuracy. An attempt to forecast the exponents at any selected cross section was moderately successful. Empirical equations are more accurate than the minimum variance, Gauckler-Manning, or Chezy methods. Predictions of the exponent of width are most reliable, the exponent of depth fair, and the exponent of mean velocity poor. (Woodard-USGS)

  7. Humeral cross-sectional shape in suspensory primates and sloths.

    PubMed

    Patel, Biren A; Ruff, Christopher B; Simons, Erin L R; Organ, Jason M

    2013-04-01

    Studies on the cross-sectional geometry of long bones in African apes have documented that shape ratios derived from second moments of area about principle axes (e.g., Imax /Imin ) are often correlated with habitual locomotor behaviors. For example, humeral cross-sections tend to appear more circular in more arboreal and forelimb suspensory chimpanzees compared with terrestrial quadrupedal gorillas. These data support the hypothesis that cross-sections that are more circular in shape are adapted for multidirectional loading regimes and bending moments encountered when using acrobatic locomotor behaviors. Whether a more circular humerus reflects greater use of forelimb suspension in other primates and nonprimate mammals is unknown. In this study, cross-sections at or near midshaft of the humerus were obtained from anthropoid primates that differ in their use of forelimb suspension, as well as from two genera of suspensory sloths. Imax /Imin ratios were compared within and between groups, and correlations were made with behavioral data. In broad comparisons, observed differences in morphology follow predicted patterns. Humeri of suspensory sloths are circular. Humeri of the more suspensory hominoids tend to be more circular than those of quadrupedal taxa. Humeri of the suspensory atelines are similar to hominoids, while those of Cebus are more like nonsuspensory cercopithecoids. There is, however, considerable overlap between taxa and within finer comparisons variation between species are not in the predicted direction. Thus, although Imax /Imin ratios of the humerus are informative for characterizing generalized locomotor modes (i.e., forelimb suspensory vs. quadrupedal), additional structural information is needed for more fine-grained assessments of locomotion.

  8. Humeral cross-sectional shape in suspensory primates and sloths.

    PubMed

    Patel, Biren A; Ruff, Christopher B; Simons, Erin L R; Organ, Jason M

    2013-04-01

    Studies on the cross-sectional geometry of long bones in African apes have documented that shape ratios derived from second moments of area about principle axes (e.g., Imax /Imin ) are often correlated with habitual locomotor behaviors. For example, humeral cross-sections tend to appear more circular in more arboreal and forelimb suspensory chimpanzees compared with terrestrial quadrupedal gorillas. These data support the hypothesis that cross-sections that are more circular in shape are adapted for multidirectional loading regimes and bending moments encountered when using acrobatic locomotor behaviors. Whether a more circular humerus reflects greater use of forelimb suspension in other primates and nonprimate mammals is unknown. In this study, cross-sections at or near midshaft of the humerus were obtained from anthropoid primates that differ in their use of forelimb suspension, as well as from two genera of suspensory sloths. Imax /Imin ratios were compared within and between groups, and correlations were made with behavioral data. In broad comparisons, observed differences in morphology follow predicted patterns. Humeri of suspensory sloths are circular. Humeri of the more suspensory hominoids tend to be more circular than those of quadrupedal taxa. Humeri of the suspensory atelines are similar to hominoids, while those of Cebus are more like nonsuspensory cercopithecoids. There is, however, considerable overlap between taxa and within finer comparisons variation between species are not in the predicted direction. Thus, although Imax /Imin ratios of the humerus are informative for characterizing generalized locomotor modes (i.e., forelimb suspensory vs. quadrupedal), additional structural information is needed for more fine-grained assessments of locomotion. PMID:23408647

  9. Windowed multipole for cross section Doppler broadening

    NASA Astrophysics Data System (ADS)

    Josey, C.; Ducru, P.; Forget, B.; Smith, K.

    2016-02-01

    This paper presents an in-depth analysis on the accuracy and performance of the windowed multipole Doppler broadening method. The basic theory behind cross section data is described, along with the basic multipole formalism followed by the approximations leading to windowed multipole method and the algorithm used to efficiently evaluate Doppler broadened cross sections. The method is tested by simulating the BEAVRS benchmark with a windowed multipole library composed of 70 nuclides. Accuracy of the method is demonstrated on a single assembly case where total neutron production rates and 238U capture rates compare within 0.1% to ACE format files at the same temperature. With regards to performance, clock cycle counts and cache misses were measured for single temperature ACE table lookup and for windowed multipole. The windowed multipole method was found to require 39.6% more clock cycles to evaluate, translating to a 7.9% performance loss overall. However, the algorithm has significantly better last-level cache performance, with 3 fewer misses per evaluation, or a 65% reduction in last-level misses. This is due to the small memory footprint of the windowed multipole method and better memory access pattern of the algorithm.

  10. Actinide Targets for Neutron Cross Section Measurements

    SciTech Connect

    John D. Baker; Christopher A. McGrath

    2006-10-01

    The Advanced Fuel Cycle Initiative (AFCI) and the Generation IV Reactor Initiative have demonstrated a lack of detailed neutron cross-sections for certain "minor" actinides, those other than the most common (235U, 238U, and 239Pu). For some closed-fuel-cycle reactor designs more than 50% of reactivity will, at some point, be derived from "minor" actinides that currently have poorly known or in some cases not measured (n,?) and (n,f) cross sections. A program of measurements under AFCI has begun to correct this. One of the initial hurdles has been to produce well-characterized, highly isotopically enriched, and chemically pure actinide targets on thin backings. Using a combination of resurrected techniques and new developments, we have made a series of targets including highly enriched 239Pu, 240Pu, and 242Pu. Thus far, we have electrodeposited these actinide targets. In the future, we plan to study reductive distillation to achieve homogeneous, adherent targets on thin metal foils and polymer backings. As we move forward, separated isotopes become scarcer, and safety concerns become greater. The chemical purification and electodeposition techniques will be described.

  11. The effects of increased nasal airway resistance on modeled velopharyngeal orifice area estimation.

    PubMed

    Smith, B E; Moon, J B; Weinberg, B

    1984-01-01

    Research has shown that cleft lip and palate individuals have higher nasal airway resistance than normal subjects (Warren, Duany, and Fischer, 1969). The present work examined the predictive nature of modeled velopharyngeal orifice area calculations obtained using the hydrokinetic equation (Warren and DuBois, 1964) under conditions simulating increased degrees of nasal obstruction. The results of this project suggested that Warren's hydrokinetic method can be used to obtain accurate estimates of velopharyngeal orifice area under conditions of increased nasal airway resistance when airflow rates are nonvariant.

  12. The effects of increased nasal airway resistance on modeled velopharyngeal orifice area estimation.

    PubMed

    Smith, B E; Moon, J B; Weinberg, B

    1984-01-01

    Research has shown that cleft lip and palate individuals have higher nasal airway resistance than normal subjects (Warren, Duany, and Fischer, 1969). The present work examined the predictive nature of modeled velopharyngeal orifice area calculations obtained using the hydrokinetic equation (Warren and DuBois, 1964) under conditions simulating increased degrees of nasal obstruction. The results of this project suggested that Warren's hydrokinetic method can be used to obtain accurate estimates of velopharyngeal orifice area under conditions of increased nasal airway resistance when airflow rates are nonvariant. PMID:6584247

  13. Effect of mouthpiece, noseclips, and head position on airway area measured by acoustic reflections.

    PubMed

    Rubinstein, I; McClean, P A; Boucher, R; Zamel, N; Fredberg, J J; Hoffstein, V

    1987-10-01

    To investigate whether it is possible to simplify the methodology of measuring airway area by acoustic reflections, we measured upper airway area in 10 healthy subjects during tidal breathing according to seven different protocols. Three protocols employed custom-made bulky mouthpiece with or without nose-clips, two protocols used a scuba-diving mouthpiece and cotton balls placed in the nostrils instead of noseclips, and two protocols employed neck flexion and extension. We found no significant difference in average pharyngeal, glottic, and tracheal areas for any of the protocols except for neck flexion, which was associated with a significantly lower mean pharyngeal area. Intraindividual variabilities were comparable for all protocols, except for protocol employing the customary bulky mouthpiece and no noseclips, which consistently resulted in the most variable measurements of area for all three airway segments: pharynx, glottis, and trachea. Furthermore, we found that the protocol employing the scuba-diving mouthpiece with or without cotton balls in the nostrils resulted in the lowest number of unacceptable measurements. We conclude that measurements of airway area by acoustic reflections may be further simplified by using a scuba-diving mouthpiece without noseclips; furthermore, control of head position during measurements is not critical provided there is no obvious neck flexion.

  14. Sucrose radical-production cross-section regarding heavy-ion irradiation

    NASA Astrophysics Data System (ADS)

    Nakagawa, Kouichi; Ikota, Nobuo; Anzai, Kazunori

    2008-05-01

    We investigated the sucrose radical-production cross-section induced by heavy-ion irradiation. L-Alanine was also used in order to compare radical yield and cross-section. The stable free radicals after irradiation were analyzed by electron paramagnetic resonance (EPR). The radical yield obtained by the irradiated samples had a logarithmic correlation with the LET (linear energy transfer). Quantitative EPR analyses showed that radical productions for sucrose and L-alanine vary both by different particle irradiation and the LET under the same absorbed dose. Furthermore, the cross-sections of radical productions for samples were calculated. Both cross-sections for C ions irradiation under LET 30 keV/μm at 50 Gy dose were ˜3.0 × 10 -9 μm 2, taking account of the molecular areas of the samples. The values of the cross-sections imply that multiple ionizing particles involve producing stable radicals.

  15. Lunar Radar Cross Section at Low Frequency

    NASA Technical Reports Server (NTRS)

    Rodriguez, P.; Kennedy, E. J.; Kossey, P.; McCarrick, M.; Kaiser, M. L.; Bougeret, J.-L.; Tokarev, Y. V.

    2002-01-01

    Recent bistatic measurements of the lunar radar cross-section have extended the spectrum to long radio wavelength. We have utilized the HF Active Auroral Research Program (HAARP) radar facility near Gakona, Alaska to transmit high power pulses at 8.075 MHz to the Moon; the echo pulses were received onboard the NASA/WIND spacecraft by the WAVES HF receiver. This lunar radar experiment follows our previous use of earth-based HF radar with satellites to conduct space experiments. The spacecraft was approaching the Moon for a scheduled orbit perturbation when our experiment of 13 September 2001 was conducted. During the two-hour experiment, the radial distance of the satellite from the Moon varied from 28 to 24 Rm, where Rm is in lunar radii.

  16. Absolute photoneutron cross sections of Sm isotopes

    SciTech Connect

    Gheorghe, I.; Glodariu, T.; Utsunomiya, H.; Filipescu, D.; Nyhus, H.-T.; Renstrom, T.; Tesileanu, O.; Shima, T.; Takahisa, K.; Miyamoto, S.

    2015-02-24

    Photoneutron cross sections for seven samarium isotopes, {sup 144}Sm, {sup 147}Sm, {sup 148}Sm, {sup 149}Sm, {sup 150}Sm, {sup 152}Sm and {sup 154}Sm, have been investigated near neutron emission threshold using quasimonochromatic laser-Compton scattering γ-rays produced at the synchrotron radiation facility NewSUBARU. The results are important for nuclear astrophysics calculations and also for probing γ-ray strength functions in the vicinity of neutron threshold. Here we describe the neutron detection system and we discuss the related data analysis and the necessary method improvements for adapting the current experimental method to the working parameters of the future Gamma Beam System of Extreme Light Infrastructure - Nuclear Physics facility.

  17. Collision cross sections for structural proteomics.

    PubMed

    Marklund, Erik G; Degiacomi, Matteo T; Robinson, Carol V; Baldwin, Andrew J; Benesch, Justin L P

    2015-04-01

    Ion mobility mass spectrometry (IM-MS) allows the structural interrogation of biomolecules by reporting their collision cross sections (CCSs). The major bottleneck for exploiting IM-MS in structural proteomics lies in the lack of speed at which structures and models can be related to experimental data. Here we present IMPACT (Ion Mobility Projection Approximation Calculation Tool), which overcomes these twin challenges, providing accurate CCSs up to 10(6) times faster than alternative methods. This allows us to assess the CCS space presented by the entire structural proteome, interrogate ensembles of protein conformers, and monitor molecular dynamics trajectories. Our data demonstrate that the CCS is a highly informative parameter and that IM-MS is of considerable practical value to structural biologists. PMID:25800554

  18. Automated segmentation of lung airway wall area measurements from bronchoscopic optical coherence tomography imaging

    NASA Astrophysics Data System (ADS)

    Heydarian, Mohammadreza; Choy, Stephen; Wheatley, Andrew; McCormack, David; Coxson, Harvey O.; Lam, Stephen; Parraga, Grace

    2011-03-01

    Chronic Obstructive Pulmonary Disease (COPD) affects almost 600 million people and is currently the fourth leading cause of death worldwide. COPD is an umbrella term for respiratory symptoms that accompany destruction of the lung parenchyma and/or remodeling of the airway wall, the sum of which result in decreased expiratory flow, dyspnea and gas trapping. Currently, x-ray computed tomography (CT) is the main clinical method used for COPD imaging, providing excellent spatial resolution for quantitative tissue measurements although dose limitations and the fundamental spatial resolution of CT limit the measurement of airway dimensions beyond the 5th generation. To address this limitation, we are piloting the use of bronchoscopic Optical Coherence Tomography (OCT), by exploiting its superior spatial resolution of 5-15 micrometers for in vivo airway imaging. Currently, only manual segmentation of OCT airway lumen and wall have been reported but manual methods are time consuming and prone to observer variability. To expand the utility of bronchoscopic OCT, automatic and robust measurement methods are required. Therefore, our objective was to develop a fully automated method for segmenting OCT airway wall dimensions and here we explore several different methods of image-regeneration, voxel clustering and post-processing. Our resultant automated method used K-means or Fuzzy c-means to cluster pixel intensity and then a series of algorithms (i.e. cluster selection, artifact removal, de-noising) was applied to process the clustering results and segment airway wall dimensions. This approach provides a way to automatically and rapidly segment and reproducibly measure airway lumen and wall area.

  19. Experiments on Antiprotons: Antiproton-Nucleon Cross Sections

    DOE R&D Accomplishments Database

    Chamberlain, Owen; Keller, Donald V.; Mermond, Ronald; Segre, Emilio; Steiner, Herbert M.; Ypsilantis, Tom

    1957-07-22

    In this paper experiments are reported on annihilation and scattering of antiprotons in H{sub 2}O , D{sub 2}O, and O{sub 2}. From the data measured it is possible to obtain an antiproton-proton and an antiproton-deuteron cross section at 457 Mev (lab). Further analysis gives the p-p and p-n cross sections as 104 mb for the p-p reaction cross section and 113 mb for the p-n reaction cross section. The respective annihilation cross sections are 89 and 74 mb. The Glauber correction necessary in order to pass from the p-d to the p-n cross section by subtraction of the p-p cross section is unfortunately large and somewhat uncertain. The data are compared with the p-p and p-n cross sections and with other results on p-p collisions.

  20. Single-level resonance parameters fit nuclear cross-sections

    NASA Technical Reports Server (NTRS)

    Drawbaugh, D. W.; Gibson, G.; Miller, M.; Page, S. L.

    1970-01-01

    Least squares analyses of experimental differential cross-section data for the U-235 nucleus have yielded single level Breit-Wigner resonance parameters that fit, simultaneously, three nuclear cross sections of capture, fission, and total.

  1. Electron Elastic-Scattering Cross-Section Database

    National Institute of Standards and Technology Data Gateway

    SRD 64 NIST Electron Elastic-Scattering Cross-Section Database (PC database, no charge)   This database provides values of differential elastic-scattering cross sections, corresponding total elastic-scattering cross sections, phase shifts, and transport cross sections for elements with atomic numbers from 1 to 96 and for electron energies between 50 eV and 20,000 eV (in steps of 1 eV).

  2. Viscous Flow through Pipes of Various Cross-Sections

    ERIC Educational Resources Information Center

    Lekner, John

    2007-01-01

    An interesting variety of pipe cross-sectional shapes can be generated, for which the Navier-Stokes equations can be solved exactly. The simplest cases include the known solutions for elliptical and equilateral triangle cross-sections. Students can find pipe cross-sections from solutions of Laplace's equation in two dimensions, and then plot the…

  3. Mental Visualization of Objects from Cross-Sectional Images

    ERIC Educational Resources Information Center

    Wu, Bing; Klatzky, Roberta L.; Stetten, George D.

    2012-01-01

    We extended the classic anorthoscopic viewing procedure to test a model of visualization of 3D structures from 2D cross-sections. Four experiments were conducted to examine key processes described in the model, localizing cross-sections within a common frame of reference and spatiotemporal integration of cross sections into a hierarchical object…

  4. Higher order representation of the beam cross section deformation in large displacement finite element analysis

    NASA Astrophysics Data System (ADS)

    Li, Pengfei; Gantoi, Florentina M.; Shabana, Ahmed A.

    2011-12-01

    Most existing beam formulations assume that the cross section of the beam remains rigid regardless of the amplitude of the displacement. The absolute nodal coordinate formulation (ANCF); however, allows for the deformation of the cross section and leads to a more general beam models that capture the coupling between different modes of displacement. This paper examines the effect of the order of interpolation on the modes of deformation of the beam cross section using ANCF finite elements. To this end, a new two-dimensional shear deformable ANCF beam element is developed. The new finite element employs a higher order of interpolation, and allows for new cross section deformation modes that cannot be captured using previously developed shear deformable ANCF beam elements. The element developed in this study relaxes the assumption of planar cross section; thereby allowing for including the effect of warping as well as for different stretch values at different points on the element cross section. The displacement field of the new element is assumed to be cubic in the axial direction and quadratic in the transverse direction. Using this displacement field, more expressions for the element extension, shear and the cross section stretch can be systematically defined. The change in the cross section area is measured using Nanson's formula. Measures of the shear angle, extension, and cross section stretch can also be systematically defined using coordinate systems defined at the element material points. Using these local coordinate systems, expressions for a nominal shear angle are obtained. The differences between the cross section deformation modes obtained using the new higher order element and those obtained using the previously developed lower order elements are highlighted. Numerical examples are presented in order to compare the results obtained using the new finite element and the results obtained using previously developed ANCF finite elements.

  5. Analysis of the influence of MOS device geometry on predicted SEU cross sections

    SciTech Connect

    Warren, K.; Massengill, L.; Schrimpf, R.; Barnaby, H.

    1999-12-01

    An investigation into the single-event sensitive area geometry of a body-tied-to-source (BTS) SOI nMOS transistor has been performed through a novel simulation technique. Results are presented which demonstrate the influence of spatial variations in charge collection efficiency on the shape of the predicted upset cross section curve. Observations are made on a technique for inferring sensitive area or intra-cell collection efficiencies from cross section data.

  6. Amyloidosis: Modern Cross-sectional Imaging.

    PubMed

    Czeyda-Pommersheim, Ferenc; Hwang, Misun; Chen, Sue Si; Strollo, Diane; Fuhrman, Carl; Bhalla, Sanjeev

    2015-01-01

    Amyloidosis is a rare diverse condition caused by the pathologic extracellular deposition of abnormal insoluble proteins throughout the body. It may exist as a primary disease or, more commonly, may be secondary to a wide variety of pathologic processes ranging from chronic infection or inflammation to malignancy. Hereditary forms also exist. On the basis of the structure of the protein deposits, more than two dozen subtypes of amyloidosis have been described. A single organ or multiple organ systems may be affected. The radiologic manifestations of amyloidosis are varied and often nonspecific, making amyloidosis a diagnostic challenge for the radiologist. In the chest, the lungs, mediastinum, pleura, and heart may be involved. Lung involvement may manifest as diffuse reticulonodular interstitial thickening, consolidations, or solitary or multiple parenchymal nodules that may calcify, cavitate, and slowly enlarge. Pleural involvement most commonly manifests as pleural effusions. Tracheobronchial involvement may exhibit concentric airway thickening, mural and intraluminal nodules, submucosal calcification, and airway obstruction. Mediastinal and hilar lymph nodes may enlarge and frequently calcify. At cardiac magnetic resonance (MR) imaging, the left ventricular wall is typically thickened, with associated diastolic dysfunction. Delayed contrast material-enhanced cardiac MR imaging typically shows global transmural or subendocardial enhancement. The pathophysiology, classification, treatment, and prognosis of amyloidosis are reviewed, followed by case examples of the appearance of thoracic and cardiac amyloidosis on chest radiographs, computed tomographic (CT) images, and cardiac MR images. PMID:26230754

  7. Abdominal sarcoidosis: cross-sectional imaging findings

    PubMed Central

    Gezer, Naciye Sinem; Başara, Işıl; Altay, Canan; Harman, Mustafa; Rocher, Laurence; Karabulut, Nevzat; Seçil, Mustafa

    2015-01-01

    Sarcoidosis is a multisystem inflammatory disease of unknown etiology. The lungs and the lymphoid system are the most commonly involved organs. Extrapulmonary involvement is reported in 30% of patients, and the abdomen is the most common extrapulmonary site with a frequency of 50%–70%. Although intra-abdominal sarcoidosis is usually asymptomatic, its presence may affect the prognosis and treatment options. The lesions are less characteristic and may mimick neoplastic or infectious diseases such as lymphoma, diffuse metastasis, and granulomatous inflammation. The liver and spleen are the most common abdominal sites of involvement. Sarcoidosis of the gastrointestinal system, pancreas, and kidneys are extremely rare. Adenopathy which is most commonly found in the porta hepatis, exudative ascites, and multiple granulomatous nodules studding the peritoneum are the reported manifestations of abdominal sarcoidosis. Since abdominal sarcoidosis is less common and long-standing, unrecognized disease can result in significant morbidity and mortality. Imaging contributes to diagnosis and management of intra-abdominal sarcoidosis. In this report we reviewed the cross-sectional imaging findings of hepatobiliary, gastrointestinal, and genitourinary sarcoidosis. PMID:25512071

  8. The hadronic cross section measurement at KLOE

    NASA Astrophysics Data System (ADS)

    Valeriani, B.; KLOE Collaboration

    2004-04-01

    KLOE uses the radiative return to measure the hadronic cross section e+e- → π +- at DANE. Theemission of one or more hard photons in the initial state ( ISR) reduces the collision energy, otherwise fixed at 1020 MeV, and allows to perform an effective scan of the two pions invariant mass squared, sπ, in the whole sπ, region from threshold to mφ2. An extremely accurate knowledge of experimental systematics, background, luminosity and, on the theoretical side, a precise description of initial state radiation are needed to perform a competitive measurement. We present here the status of the analysis of 140 pb -1 collected in 2001. A preliminary evaluation of the hadronic contribution to aμ in the sπ range between 0.37 GeV 2 and 0.93 GeV 2 yields aμ = 378.4 ± 0.8 stat ± 4.5 syst ± 3.0 theo ± 3.8 FSR, consistent with the CMD-2 result and confirming the present discrepancy between e+e - and τ data.

  9. [Fast neutron cross section measurements]. Progress report

    SciTech Connect

    Knoll, G.F.

    1992-10-26

    From its inception, the Nuclear Data Project at the University of Michigan has concentrated on two major objectives: (1) to carry out carefully controlled nuclear measurements of the highest possible reliability in support of the national nuclear data program, and (2) to provide an educational opportunity for students with interests in experimental nuclear science. The project has undergone a successful transition from a primary dependence on our photoneutron laboratory to one in which our current research is entirely based on a unique pulsed 14 MeV fast neutron facility. The new experimental facility is unique in its ability to provide nanosecond bursts of 14 MeV neutrons under conditions that are ``clean`` and as scatter-free as possible, and is the only one of its type currently in operation in the United States. It has been designed and put into operation primarily by graduate students, and has met or exceeded all of its important initial performance goals. We have reached the point of its routine operation, and most of the data are now in hand that will serve as the basis for the first two doctoral dissertations to be written by participating graduate students. Our initial results on double differential neutron cross sections will be presented at the May 1993 Fusion Reactor Technology Workshop. We are pleased to report that, after investing several years in equipment assembly and optimization, the project has now entered its ``data production`` phase.

  10. Electron-impact-ionization cross section for the hydrogen atom

    NASA Astrophysics Data System (ADS)

    Hu, W.; Fang, D.; Wang, Y.; Yang, F.

    1994-02-01

    A distorted-wave Born exchange approximation was used to calculate the cross section for electron-impact ionization of the hydrogen atoms. Both the integral and energy-differential cross section were calculated. The results were compared with the latest experimental data and other theoretical calculations. Comparison shows that the calculations agree with differential cross-section measurements in general. For integral cross sections the calculation shows a better agreement with an earlier measurement [M.B. Shah, D. S. Elliott, and H. B. Gilbody, J. Phys. B 20, 3501 (1987)] in which the cross sections are normalized to the first Born approximation.

  11. Graphs of the cross sections in the recommended Monte Carlo cross-section library at the Los Alamos Scientific Laboratory

    SciTech Connect

    Soran, P.D.; Seamon, R.E.

    1980-05-01

    Graphs of all neutron cross sections and photon production cross sections on the Recommended Monte Carlo Cross Section (RMCCS) library have been plotted along with local neutron heating numbers. Values for anti ..nu.., the average number of neutrons per fission, are also given.

  12. Upper airway segmentation and measurement in MRI using fuzzy connectedness

    NASA Astrophysics Data System (ADS)

    Liu, Jianguo; Udupa, Jayaram K.; Odhner, Dewey; McDonough, Joe M.; Arens, Raanan

    2002-04-01

    The purpose of this work is to build a computerized system for the delineation of upper airway structures via MRI and to evaluate its effectiveness for routine clinical use in aiding diagnosis of upper airway disorders in children. We use two MRI protocols, axial T1 and T2, to gather information about different aspects of the airway and its surrounding soft tissue structures including adenoid, tonsils, tongue and soft palate. These images are processed and segmented to compute the architectural parameters of the airway such as its surface description, volume, central (medial) line, and cross-sectional areas at planes orthogonal to the central line. We have built a software package based on 3DVIEWNIX and running on a 450 MHz Pentium PC under Linux system (and on a Sun workstation under Unix) for the various operations of visualization, segmentation, registration, prefiltering, interpolation, standardization, and quantitative analysis of the airway. The system has been tested utilizing 40 patient studies. For every study, the system segmented and displayed a smooth 3D rendition of the airway, its central line and a plot of the cross-sectional area of the airway orthogonal to the central line as a function of the distance from one end of the central line. The tests indicate 97% precision and accuracy for segmentation. The mean time taken per study is about 4 minutes for the airway. This includes operator interaction time and processing time. This method provides a robust and fast means of assessing the airway size, shape, and places of restriction, as well as providing a structural data set suitable for use in modeling studies of airflow and mechanics.

  13. Realizing the Opportunities of Neutron Cross Section Measurements at RIA

    SciTech Connect

    Ahle, L; Hausmann, M; Reifarth, R; Roberts, K; Roeben, M; Rusnak, B; Vieira, D

    2004-10-13

    The Rare Isotope Accelerator will produce many isotopes at never before seen rates. This will allow for the first time measurements on isotopes very far from stability and new measurement opportunities for unstable nuclei near stability. In fact, the production rates are such that it should be possible to collect 10 micrograms of many isotopes with a half-life of 1 day or more. This ability to make targets of short-lived nuclei enables the possibility of making neutron cross-section measurements important to the astrophysics and the stockpile stewardship communities. But to fully realize this opportunity, the appropriate infrastructure must be included at the RIA facility. This includes isotope harvesting capabilities, radiochemical areas for processing collected material, and an intense, ''mono-energetic'', tunable neutron source. As such, we have been developing a design for neutron source facility to be included at the RIA site. This facility would produce neutrons via intense beams of deuterons and protons on a variety of targets. The facility would also include the necessary radiochemical facilities for target processing. These infrastructure needs will be discussed in addition to the methods that would be employed at RIA for measuring these neutron cross-sections.

  14. Retrodeformable cross sections and Oak Ridge fault, Ventura basin, California

    SciTech Connect

    Yeats, R.S.; Huftile, G.F.

    1988-03-01

    A retrodeformable (balanced) cross section is constructed such that stratified rocks are restored to their undeformed state without loss or gain of bed length or bed thickness. Ductile strata may be area-balanced if original thickness is known. Near Ventura, folds in Pliocene-Pleistocene turbidites and Miocene-early Pliocene shales (Rincon, Monterey, Sisquoc) overlie an unfolded competent Paleogene sequence. The basal decollement of the foldbelt is in the ductile Rincon Formation (lower Miocene). The overlying Sulphur Mountain, Ventura Avenue, San Miguelito, and Rincon anticlines are fault-propagation folds developing from south-dipping, largely late Quaternary frontal ramp thrusts (Sisar-Big Canyon-Lion fault set, Barnard fault set, padre Juan fault, and C-3 fault, respectively) that rise from the decollement. Cross-section balancing shows that the overlying fold-thrust belt has shortened 2.5-6 km more than subjacent Paleogene competent strata. This excess bed length is taken up in the Paleogene sequence on the Oak Ridge fault as a ramp from the brittle-plastic transition zone through the upper crust. This implies that the basal decollement is the frontal active thrust of the Oak Ridge fault. The decollement dies out southeast of a line between Timber Canyon oil field and the west end of Oak Ridge, possibly because of decreased ductility in the Miocene decollement sequence due to appearance of sandstone interbeds. Farther southeast, late Quaternary displacement concentrated on the Oak Ridge fault itself at rates greater than 10 mm/year.

  15. Optimal cross-sectional sampling for river modelling with bridges: An information theory-based method

    NASA Astrophysics Data System (ADS)

    Ridolfi, E.; Alfonso, L.; Di Baldassarre, G.; Napolitano, F.

    2016-06-01

    The description of river topography has a crucial role in accurate one-dimensional (1D) hydraulic modelling. Specifically, cross-sectional data define the riverbed elevation, the flood-prone area, and thus, the hydraulic behavior of the river. Here, the problem of the optimal cross-sectional spacing is solved through an information theory-based concept. The optimal subset of locations is the one with the maximum information content and the minimum amount of redundancy. The original contribution is the introduction of a methodology to sample river cross sections in the presence of bridges. The approach is tested on the Grosseto River (IT) and is compared to existing guidelines. The results show that the information theory-based approach can support traditional methods to estimate rivers' cross-sectional spacing.

  16. NASA-Lewis experiences with multigroup cross sections and shielding calculations

    NASA Technical Reports Server (NTRS)

    Lahti, G. P.

    1972-01-01

    The nuclear reactor shield analysis procedures employed at NASA-Lewis are described. Emphasis is placed on the generation, use, and testing of multigroup cross section data. Although coupled neutron and gamma ray cross section sets are useful in two dimensional Sn transport calculations, much insight has been gained from examination of uncoupled calculations. These have led to experimental and analytic studies of areas deemed to be of first order importance to reactor shield calculations. A discussion is given of problems encountered in using multigroup cross sections in the resolved resonance energy range. The addition to ENDF files of calculated and/or measured neutron-energy-dependent capture gamma ray spectra for shielding calculations is questioned for the resonance region. Anomalies inherent in two dimensional Sn transport calculations which may overwhelm any cross section discrepancies are illustrated.

  17. High E{sub T} jet cross sections at CDF

    SciTech Connect

    Flaugher, B.; CDF Collaboration

    1996-08-01

    The inclusive jet cross section for {ital p}{ital {anti p}} collisions at {radical}s = 1.8 TeV as measured by the CDF collaboration will be presented. Preliminary CDF measurements of the {Sigma} E{sub T} cross section at {radical}s = 1.8 TeV and the central inclusive jet cross section at {radical}s = 0.630 TeV will also be shown.

  18. Measured microwave scattering cross sections of three meteorite specimens

    NASA Technical Reports Server (NTRS)

    Hughes, W. E.

    1972-01-01

    Three meteorite specimens were used in a microwave scattering experiment to determine the scattering cross sections of stony meteorites and iron meteorites in the frequency range from 10 to 14 GHz. The results indicate that the stony meteorites have a microwave scattering cross section that is 30 to 50 percent of their projected optical cross section. Measurements of the iron meteorite scattering were inconclusive because of specimen surface irregularities.

  19. Projectile and Lab Frame Differential Cross Sections for Electromagnetic Dissociation

    NASA Technical Reports Server (NTRS)

    Norbury, John W.; Adamczyk, Anne; Dick, Frank

    2008-01-01

    Differential cross sections for electromagnetic dissociation in nuclear collisions are calculated for the first time. In order to be useful for three - dimensional transport codes, these cross sections have been calculated in both the projectile and lab frames. The formulas for these cross sections are such that they can be immediately used in space radiation transport codes. Only a limited amount of data exists, but the comparison between theory and experiment is good.

  20. Analytical formulation of the quantum electromagnetic cross section

    NASA Astrophysics Data System (ADS)

    Brandsema, Matthew J.; Narayanan, Ram M.; Lanzagorta, Marco

    2016-05-01

    It has been found that the quantum radar cross section (QRCS) equation can be written in terms of the Fourier transform of the surface atom distribution of the object. This paper uses this form to provide an analytical formulation of the quantum radar cross section by deriving closed form expressions for various geometries. These expressions are compared to the classical radar cross section (RCS) expressions and the quantum advantages are discerned from the differences in the equations. Multiphoton illumination is also briefly discussed.

  1. Flow in tubes of non-circular cross-sections

    NASA Astrophysics Data System (ADS)

    Quadir, Raushan Ara

    Laminar, viscous, incompressible flow in tubes of noncircular cross sections is investigated. The specific aims of the investigation are (1) to look at the problems of both developing flow and fully developed flow, (2) to consider noncircular cross sections in a more systematic manner than has been done in the past, and (3) to develop a relatively simple finite element technique for producing accurate numerical solutions of flow in tubes of fairly arbitrary cross sections. Fully developed flow in tubes is governed by a Poisson type equation for the mainstream velocity. Both analytical and numerical solutions are considered. The cross sections studied include elliptic and rectangular cross sections of different aspect ratios, some triangular cross sections, and a series of crescent-shaped cross sections. The physical characteristics of the flow are examined in a systematic manner in order to determine how these characteristics are affected by certain geometrical features of the cross section. Solutions fall into three basic categories depending on the shape of the cross section. In the first category, which includes circular and elliptic cross sections, solutions are possible in closed form. In the second, including rectangular and some triangular cross sections, solutions are in the form of infinite series. In the third, including cross sections of more complicated or irregular shapes, only numerical solutions are possible. Results of calculations of velocity profiles, flow rate, pumping power, and friction factor are presented in a way which can be useful for engineering applications. In numerical studies of both developing and fully developed flow finite element techniques are used. Results are obtained for tubes of rectangular and elliptic cross sections of different aspect ratios, for tubes of crescent-shaped cross sections, and a tube whose cross section is an oval of Cassini. For fully developed flow, results are compared with the corresponding exact

  2. Flow in Tubes of Non-Circular Cross-Sections

    NASA Astrophysics Data System (ADS)

    Quadir, Raushan Ara

    In this thesis steady, laminar, viscous, incompressible flow in tubes of non-circular cross sections is investigated. The specific aims of the investigation are (a) to look at the problems of both developing flow and fully developed flow, (b) to consider non-circular cross sections in a more systematic manner than has been done in the past, and (c) to develop a relatively simple finite element technique for producing accurate numerical solutions of flow in tubes of fairly arbitrary cross sections. Fully developed flow in tubes is governed by a Poisson type equation for the mainstream velocity. Both analytical and numerical solutions are considered. The cross sections studied include elliptic and rectangular cross sections of different aspect ratios, some triangular cross sections, and a series of crescent-shaped cross sections. The physical characteristics of the flow are examined in a systematic manner in order to determine how these characteristics are affected by certain geometrical features of the cross section. Solutions fall into three basic categories depending on the shape of the cross section. In the first category, which includes circular and elliptic cross sections, solutions are possible in closed form. In the second, including rectangular and some triangular cross sections, solutions are in the form of infinite series. In the third, including cross sections of more complicated or irregular shapes, only numerical solutions are possible. Results of calculations of velocity profiles, flow rate, pumping power, and friction factor are presented in a way which can be useful for engineering applications. In numerical studies of both developing and fully developed flow finite element techniques are used. Results are obtained for tubes of rectangular and elliptic cross sections of different aspect ratios, for tubes of crescent -shaped cross sections and a tube whose cross section is an oval of Cassini. For fully developed flow, results are compared with the

  3. Documentation of Uncertainties in Experimental Cross Sections for EXFOR

    SciTech Connect

    Otuka, N.; Smith, D.L.

    2014-06-15

    Documentation of uncertainties and covariances in experimental nuclear reaction cross sections has been assessed. Following consideration of the importance of covariances for nuclear data in various nuclear applications, and presentation of a simple numerical example to demonstrate this point, the minimum basic concepts (mean, covariance, standard derivation, partial uncertainties, micro- and macro-correlation coefficients) are introduced. A deterministic approach to propagating the covariances in primary measured parameters (e.g., counts) to the derived cross sections is discussed, using a neutron-induced activation cross section measurement as an example. Finally, various approaches to documentation (publication, compilation) of experimental cross sections to facilitate their use in future evaluations are mentioned.

  4. Neutron-capture Cross Sections from Indirect Measurements

    SciTech Connect

    Escher, J E; Burke, J T; Dietrich, F S; Ressler, J J; Scielzo, N D; Thompson, I J

    2011-10-18

    Cross sections for compound-nuclear reactions play an important role in models of astrophysical environments and simulations of the nuclear fuel cycle. Providing reliable cross section data remains a formidable task, and direct measurements have to be complemented by theoretical predictions and indirect methods. The surrogate nuclear reactions method provides an indirect approach for determining cross sections for reactions on unstable isotopes, which are difficult or impossible to measure otherwise. Current implementations of the method provide useful cross sections for (n,f) reactions, but need to be improved upon for applications to capture reactions.

  5. Thermal Neutron Capture Cross Section of 22Ne

    NASA Astrophysics Data System (ADS)

    Belgya, T.; Uberseder, E.; Petrich, D.; Käppeler, F.

    2009-01-01

    The radiative thermal neutron capture cross section of the astrophysically important 22Ne nucleus has been measured at the guided cold neutron beam of the Budapest Research Reactor. High-pressure gas-bottles filled with mixtures of enriched 22Ne and CH4 were used. The cross section was determined by means of the comparator method, and an improved decay-scheme obtained in this work. The new value for the thermal neutron cross section is 52.7±0.7 mb, 18% larger than the accepted value. The influence of the new cross section on the astrophysical reaction rate is under investigation.

  6. Development of radar cross section analysis system of naval ships

    NASA Astrophysics Data System (ADS)

    Kim, Kookhyun; Kim, Jin-Hyeong; Choi, Tae-Muk; Cho, Dae-Seung

    2012-03-01

    A software system for a complex object scattering analysis, named SYSCOS, has been developed for a systematic radar cross section (RCS) analysis and reduction design. The system is based on the high frequency analysis methods of physical optics, geometrical optics, and physical theory of diffraction, which are suitable for RCS analysis of electromagnetically large and complex targets as like naval ships. In addition, a direct scattering center analysis function has been included, which gives relatively simple and intuitive way to discriminate problem areas in design stage when comparing with conventional image-based approaches. In this paper, the theoretical background and the organization of the SYSCOS system are presented. To verify its accuracy and to demonstrate its applicability, numerical analyses for a square plate, a sphere and a cylinder, a weapon system and a virtual naval ship have been carried out, of which results have been compared with analytic solutions and those obtained by the other existing software.

  7. Modeled velopharyngeal orifice area prediction during simulated stop consonant production in the presence of increased nasal airway resistance.

    PubMed

    Smith, B E; Maddox, C M; Kostinski, A B

    1985-07-01

    This project examined modeled velopharyngeal orifice area estimation under conditions simulating voiceless stop consonant production in the presence of nasal airway obstruction. The results indicated that accurate estimates of velopharyngeal orifice area can be obtained using Warren's hydrokinetic equation during aerodynamic events like those known to exist during speech in the presence of increased nasal airway resistance. These findings provide support for clinical and research use of Warren's pressure-flow approach to investigate velopharyngeal function during speech production.

  8. Modeled velopharyngeal orifice area prediction during simulated stop consonant production in the presence of increased nasal airway resistance.

    PubMed

    Smith, B E; Maddox, C M; Kostinski, A B

    1985-07-01

    This project examined modeled velopharyngeal orifice area estimation under conditions simulating voiceless stop consonant production in the presence of nasal airway obstruction. The results indicated that accurate estimates of velopharyngeal orifice area can be obtained using Warren's hydrokinetic equation during aerodynamic events like those known to exist during speech in the presence of increased nasal airway resistance. These findings provide support for clinical and research use of Warren's pressure-flow approach to investigate velopharyngeal function during speech production. PMID:3860307

  9. Neutron Fission of 235,237,239U and 241,243Pu: Cross Sections, Integral Cross Sections and Cross Sections on Excited States

    SciTech Connect

    Younes, W; Britt, H C

    2003-07-10

    In a recent paper submitted to Phys. Rev. C they have presented estimates for (n,f) cross sections on a series of Thorium, Uranium and Plutonium isotopes over the range E{sub n} = 0.1-2.5 MeV. The (n,f) cross sections for many of these isotopes are difficult or impossible to measure in the laboratory. The cross sections were obtained from previous (t,pf) reaction data invoking a model which takes into account the differences between (t,pf) and (n,f) reaction processes, and which includes improved estimates for the neutron compound formation process. The purpose of this note is: (1) to compare the estimated cross sections to current data files in both ENDF and ENDL databases; (2) to estimate ratios of cross sections relatively to {sup 235}U integrated over the ''tamped flattop'' critical assembly spectrum that was used in the earlier {sup 237}U report; and (3) to show the effect on the integral cross sections when the neutron capturing state is an excited rotational state or an isomer. The isomer and excited state results are shown for {sup 235}U and {sup 237}U.

  10. Cross Sections for Inner-Shell Ionization by Electron Impact

    SciTech Connect

    Llovet, Xavier; Powell, Cedric J.; Salvat, Francesc; Jablonski, Aleksander

    2014-03-15

    An analysis is presented of measured and calculated cross sections for inner-shell ionization by electron impact. We describe the essentials of classical and semiclassical models and of quantum approximations for computing ionization cross sections. The emphasis is on the recent formulation of the distorted-wave Born approximation by Bote and Salvat [Phys. Rev. A 77, 042701 (2008)] that has been used to generate an extensive database of cross sections for the ionization of the K shell and the L and M subshells of all elements from hydrogen to einsteinium (Z = 1 to Z = 99) by electrons and positrons with kinetic energies up to 1 GeV. We describe a systematic method for evaluating cross sections for emission of x rays and Auger electrons based on atomic transition probabilities from the Evaluated Atomic Data Library of Perkins et al. [Lawrence Livermore National Laboratory, UCRL-ID-50400, 1991]. We made an extensive comparison of measured K-shell, L-subshell, and M-subshell ionization cross sections and of Lα x-ray production cross sections with the corresponding calculated cross sections. We identified elements for which there were at least three (for K shells) or two (for L and M subshells) mutually consistent sets of cross-section measurements and for which the cross sections varied with energy as expected by theory. The overall average root-mean-square deviation between the measured and calculated cross sections was 10.9% and the overall average deviation was −2.5%. This degree of agreement between measured and calculated ionization and x-ray production cross sections was considered to be very satisfactory given the difficulties of these measurements.

  11. Calculation of cross sections for binary reactions between heavy ion projectiles and heavy actinide targets

    SciTech Connect

    Hoffman, D.C.; Hoffman, M.M.

    1990-11-01

    The computer program, described in this report, is identified as PWAVED5. It was developed to calculate cross sections for nucleon transfer reactions in low energy heavy ion bombardments. The objective was to calculate cross sections that agree with experimental results for ions of different charge and mass and to develop a predictive capability. It was undertaken because previous heavy ion calculations, for which programs were readily available, appeared to focus primarily on reactions resulting in compound nucleus formation and were not particularly applicable to calculations of binary reaction cross sections at low interaction energies. There are to principal areas in which this computation differs from several other partial wave calculations of heavy-ion reaction cross sections. First, this program is designed specifically to calculate cross sections for nucleon exchange interactions and to exclude interactions that are expected to result in fusion of the two nuclei. A second major difference in this calculation is the use of a statistical distribution to assign the total interaction cross section to individual final mass states.

  12. Electron induced inelastic and ionization cross section for plasma modeling

    NASA Astrophysics Data System (ADS)

    Verma, Pankaj; Mahato, Dibyendu; Kaur, Jaspreet; Antony, Bobby

    2016-09-01

    The present paper reports electron impact total inelastic and ionization cross section for silicon, germanium, and tin tetrahalides at energies varying from ionization threshold of the target to 5000 eV. These cross section data over a wide energy domain are very essential to understand the physico-chemical processes involved in various environments such as plasma modeling, semiconductor etching, atmospheric sciences, biological sciences, and radiation physics. However, the cross section data on the above mentioned molecules are scarce. In the present article, we report the computation of total inelastic cross section using spherical complex optical potential formalism and the estimation of ionization cross section through a semi-empirical method. The present ionization cross section result obtained for SiCl4 shows excellent agreement with previous measurements, while other molecules have not yet been investigated experimentally. Present results show more consistent behaviour than previous theoretical estimates. Besides cross sections, we have also studied the correlation of maximum ionization cross section with the square root of the ratio of polarizability to ionization potential for the molecules with known polarizabilities. A linear relation is observed between these quantities. This correlation is used to obtain approximate polarizability volumes for SiBr4, SiI4, GeCl4, GeBr4, and GeI4 molecules.

  13. Electron impact on atmospheric gases. I - Updated cross sections

    NASA Technical Reports Server (NTRS)

    Jackman, C. H.; Garvey, R. H.; Green, A. E. S.

    1977-01-01

    The analytic characterizations of electron impact cross sections for important atmospheric gases (namely, O2, N2, O, CO, CO2, and He) are updated. With these cross sections it is simple to communicate massive quantities of experimental and theoretical results. In addition, these forms are convenient for applications in energy degradation calculations, including a new approach described in a companion paper.

  14. Cross Sections for Electron Collisions with Carbon Monoxide

    SciTech Connect

    Itikawa, Yukikazu

    2015-03-15

    Cross section data are collected and reviewed for electron collisions with carbon monoxide. Collision processes included are total scattering, elastic scattering, momentum transfer, excitations of rotational, vibrational and electronic states, ionization, and dissociation. For each process, recommended values of the cross sections are presented, when possible. The literature has been surveyed through to the end of 2013.

  15. Learning of Cross-Sectional Anatomy Using Clay Models

    ERIC Educational Resources Information Center

    Oh, Chang-Seok; Kim, Ji-Young; Choe, Yeon Hyeon

    2009-01-01

    We incorporated clay modeling into gross anatomy and neuro-anatomy courses to help students understand cross-sectional anatomy. By making clay models, cutting them and comparing cut surfaces to CT and MR images, students learned how cross-sectional two-dimensional images were created from three-dimensional structure of human organs. Most students…

  16. Cross sections for electron collisions with nitric oxide

    NASA Astrophysics Data System (ADS)

    Itikawa, Yukikazu

    2016-09-01

    Cross section data are reviewed for electron collisions with nitric oxide. Collision processes considered are total scattering, elastic scattering, momentum transfer, excitations of rotational, vibrational, and electronic states, ionization, and dissociative electron attachment. After a survey of the literature (up to the end of 2015), recommended values of the cross section are determined, as far as possible.

  17. Benchmark Calculations of Electron-Impact Differential Cross Sections

    SciTech Connect

    Bray, I.; Bostock, C. J.; Fursa, D. V.; Hines, C. W.; Kadyrov, A. S.; Stelbovics, A. T.

    2011-05-11

    The calculation of electron-atom excitation and ionization cross section is considered in both the non-relativistic and relativistic scattering theory. We consider electron collisions with H, He, Cs, and Hg. Differential cross sections for elastic scattering and ionization are presented.

  18. Analysis of cross sections using various nuclear potential

    SciTech Connect

    Aziz, Azni Abdul; Kassim, Hasan Abu; Yusof, Norhasliza; Muhammad Zamrun, F.

    2014-05-02

    The relevant astrophysical reaction rates which are derived from the reaction cross sections are necessary input to the reaction network. In this work, we analyse several theoretical models of the nuclear potential which give better prediction of the cross sections for some selected reactions.

  19. Temperature-dependent high resolution absorption cross sections of propane

    NASA Astrophysics Data System (ADS)

    Beale, Christopher A.; Hargreaves, Robert J.; Bernath, Peter F.

    2016-10-01

    High resolution (0.005 cm-1) absorption cross sections have been measured for pure propane (C3H8). These cross sections cover the 2550-3500 cm-1 region at five temperatures (from 296 to 700 K) and were measured using a Fourier transform spectrometer and a quartz cell heated by a tube furnace. Calibrations were made by comparison to the integrated cross sections of propane from the Pacific Northwest National Laboratory. These are the first high resolution absorption cross sections of propane for the 3 μm region at elevated temperatures. The cross sections provided may be used to monitor propane in combustion environments and in astronomical sources such as the auroral regions of Jupiter, brown dwarfs and exoplanets.

  20. Analytical approximations for x-ray cross sections III

    SciTech Connect

    Biggs, F; Lighthill, R

    1988-08-01

    This report updates our previous work that provided analytical approximations to cross sections for both photoelectric absorption of photons by atoms and incoherent scattering of photons by atoms. This representation is convenient for use in programmable calculators and in computer programs to evaluate these cross sections numerically. The results apply to atoms of atomic numbers between 1 and 100 and for photon energiesgreater than or equal to10 eV. The photoelectric cross sections are again approximated by four-term polynomials in reciprocal powers of the photon energy. There are now more fitting intervals, however, than were used previously. The incoherent-scattering cross sections are based on the Klein-Nishina relation, but use simpler approximate equations for efficient computer evaluation. We describe the averaging scheme for applying these atomic results to any composite material. The fitting coefficients are included in tables, and the cross sections are shown graphically. 100 graphs, 1 tab.

  1. Fission cross section measurements of actinides at LANSCE

    SciTech Connect

    Tovesson, Fredrik; Laptev, Alexander B; Hill, Tony S

    2010-01-01

    Fission cross sections of a range of actinides have been measured at the Los Alamos Neutron Science Center (LANSCE) in support of nuclear energy applications. By combining measurement at two LANSCE facilities, Lujan Center and the Weapons Neutron Research center (WNR), differential cross sections can be measured from sub-thermal energies up to 200 MeV. Incident neutron energies are determined using the time-of-flight method, and parallel-plate ionization chambers are used to measure fission cross sections relative to the {sup 235}U standard. Recent measurements include the {sup 233,238}U, {sup 239,242}Pu and {sup 243}Am neutron-induced fission cross sections. In this paper preliminary results for cross section data of {sup 243}Am and {sup 233}U will be presented.

  2. Temperature-dependent absorption cross sections for hydrogen peroxide vapor

    NASA Technical Reports Server (NTRS)

    Nicovich, J. M.; Wine, P. H.

    1988-01-01

    Relative absorption cross sections for hydrogen peroxide vapor were measured over the temperature ranges 285-381 K for lambda = 230 nm-295 nm and 300-381 K for lambda = 193 nm-350 nm. The well established 298 K cross sections at 202.6 and 228.8 nm were used as an absolute calibration. A significant temperature dependence was observed at the important tropospheric photolysis wavelengths lambda over 300 nm. Measured cross sections were extrapolated to lower temperatures, using a simple model which attributes the observed temperature dependence to enhanced absorption by molecules possessing one quantum of O-O stretch vibrational excitation. Upper tropospheric photodissociation rates calculated using the extrapolated cross sections are about 25 percent lower than those calculated using currently recommended 298 K cross sections.

  3. EGAF: Measurement and Analysis of Gamma-ray Cross Sections

    NASA Astrophysics Data System (ADS)

    Firestone, R. B.; Abusaleem, K.; Basunia, M. S.; Bečvář, F.; Belgya, T.; Bernstein, L. A.; Choi, H. D.; Escher, J. E.; Genreith, C.; Hurst, A. M.; Krtička, M.; Renne, P. R.; Révay, Zs.; Rogers, A. M.; Rossbach, M.; Siem, S.; Sleaford, B.; Summers, N. C.; Szentmiklosi, L.; van Bibber, K.; Wiedeking, M.

    2014-05-01

    The Evaluated Gamma-ray Activation File (EGAF) is the result of a 2000-2007 IAEA Coordinated Research Project to develop a database of thermal, prompt γ-ray cross sections, σγ, for all elemental and selected radioactive targets. No previous database of this kind had existed. EGAF was originally based on measurements using guided neutron beams from the Budapest Reactor on all elemental targets from Z=1-82, 90 and 92, except for He and Pm. The EGAF σγ data were published in the Database of Prompt Gamma Rays from Slow Neutron Capture for Elemental Analysis [1]. An international collaboration has formed to continue the EGAF measurements with isotopically enriched targets, derive total radiative thermal neutron cross sections, σ0, extend the σγ data from thermal to 20 MeV neutrons, compile a completed activation data file, improve sections of the Reference Input Parameter Library (RIPL) with more complete and up to date level and γ-ray data, evaluate statistical γ-ray data from reaction studies, and determine recommended neutron separations energies, Sn, for atomic mass evaluations. A new guided neutron beam facility has become available at the Garching (Munich) FRM II Reactor, and high energy neutron experimental facilities are being developed by a Berkeley area collaboration where 5-33 MeV neutron beams are available at the LBNL 88” cyclotron, 2.5 and 14 MeV beams at the University of California, Berkeley neutron generator laboratory, and high flux, 10 nṡcmṡ-2 s-1, neutron pulses available from the LLNL National Ignition Facility (NIF).

  4. Collision Cross Sections for 20 Protonated Amino Acids: Fourier Transform Ion Cyclotron Resonance and Ion Mobility Results

    NASA Astrophysics Data System (ADS)

    Anupriya; Jones, Chad A.; Dearden, David V.

    2016-08-01

    We report relative dephasing cross sections for the 20 biogenic protonated amino acids measured using the cross sectional areas by Fourier transform ion cyclotron resonance (CRAFTI) technique at 1.9 keV in the laboratory reference frame, as well as momentum transfer cross sections for the same ions computed from Boltzmann-weighted structures determined using molecular mechanics. Cross sections generally increase with increasing molecular weight. Cross sections for aliphatic and aromatic protonated amino acids are larger than the average trend, suggesting these side chains do not fold efficiently. Sulfur-containing protonated amino acids have smaller than average cross sections, reflecting the mass of the S atom. Protonated amino acids that can internally hydrogen-bond have smaller than average cross sections, reflecting more extensive folding. The CRAFTI measurements correlate well with results from drift ion mobility (IMS) and traveling wave ion mobility (TWIMS) spectrometric measurements; CRAFTI results correlate with IMS values approximately as well as IMS and TWIMS values from independent measurements correlate with each other. Both CRAFTI and IMS results correlate well with the computed momentum transfer cross sections, suggesting both techniques provide accurate molecular structural information. Absolute values obtained using the various methods differ significantly; in the case of CRAFTI, this may be due to errors in measurements of collision gas pressure, measurement of excitation voltage, and/or dependence of cross sections on kinetic energy.

  5. Collision Cross Sections for 20 Protonated Amino Acids: Fourier Transform Ion Cyclotron Resonance and Ion Mobility Results.

    PubMed

    Anupriya; Jones, Chad A; Dearden, David V

    2016-08-01

    We report relative dephasing cross sections for the 20 biogenic protonated amino acids measured using the cross sectional areas by Fourier transform ion cyclotron resonance (CRAFTI) technique at 1.9 keV in the laboratory reference frame, as well as momentum transfer cross sections for the same ions computed from Boltzmann-weighted structures determined using molecular mechanics. Cross sections generally increase with increasing molecular weight. Cross sections for aliphatic and aromatic protonated amino acids are larger than the average trend, suggesting these side chains do not fold efficiently. Sulfur-containing protonated amino acids have smaller than average cross sections, reflecting the mass of the S atom. Protonated amino acids that can internally hydrogen-bond have smaller than average cross sections, reflecting more extensive folding. The CRAFTI measurements correlate well with results from drift ion mobility (IMS) and traveling wave ion mobility (TWIMS) spectrometric measurements; CRAFTI results correlate with IMS values approximately as well as IMS and TWIMS values from independent measurements correlate with each other. Both CRAFTI and IMS results correlate well with the computed momentum transfer cross sections, suggesting both techniques provide accurate molecular structural information. Absolute values obtained using the various methods differ significantly; in the case of CRAFTI, this may be due to errors in measurements of collision gas pressure, measurement of excitation voltage, and/or dependence of cross sections on kinetic energy. Graphical Abstract ᅟ. PMID:27220844

  6. XSECT: A computer code for generating fuselage cross sections - user's manual

    NASA Technical Reports Server (NTRS)

    Ames, K. R.

    1982-01-01

    A computer code, XSECT, has been developed to generate fuselage cross sections from a given area distribution and wing definition. The cross sections are generated to match the wing definition while conforming to the area requirement. An iterative procedure is used to generate each cross section. Fuselage area balancing may be included in this procedure if desired. The code is intended as an aid for engineers who must first design a wing under certain aerodynamic constraints and then design a fuselage for the wing such that the contraints remain satisfied. This report contains the information necessary for accessing and executing the code, which is written in FORTRAN to execute on the Cyber 170 series computers (NOS operating system) and produces graphical output for a Tektronix 4014 CRT. The LRC graphics software is used in combination with the interface between this software and the PLOT 10 software.

  7. Health-related quality of life and long-term care needs among elderly individuals living alone: a cross-sectional study in rural areas of Shaanxi Province, China

    PubMed Central

    2013-01-01

    Background The number of elderly individuals living alone is rising, especially in rural areas of China, and their health-related quality of life (HRQoL) is an increasing public health concern. However, little is known about factors that influence HRQoL and the need for long-term care services. The aim of the study was to identify these factors and the long-term care requirements of persons aged 60 and older living alone in rural areas of Shaanxi Province, China. Methods The study included 424 older subjects, selected by stratified random sampling. Logistic regression adjusted for age was conducted to analyze factors influencing HRQoL and the need for long-term care services. Pearson correlative analysis was conducted to assess the correlation between HRQoL score and long-term care needs. Results HRQoL among elderly subjects living alone declined with age in both males and females. The main diseases influencing HRQoL among the elderly were hypertension, cardiac disease, chronic bronchitis, neurological disease and cancer. Cataract disease was the most important factor related to HRQoL. This was followed by long-term care needs, living conditions, economic status, Cardiovascular disease, osteoporosis and age. Factors affecting long-term care needs were economic status, education level, alcohol intake, living conditions, general health and age. HRQoL and long-term care needs among this elderly population were significantly correlated (r=−0.204, p<0.01). Conclusions For elderly persons living alone, factors such as chronic disease, lower income level and living in a rural area may limit their ability to form social relationships. Reducing the level of loneliness, with better care and support, may be helpful in improving their HRQoL. There is a need for an overall improvement in the planning, provision and financing of long-term care and psychogeriatric services for elderly individuals living alone in China. PMID:23566211

  8. Correlation between hyoid bone position and airway dimensions in Chinese adolescents by cone beam computed tomography analysis.

    PubMed

    Jiang, Y-Y

    2016-07-01

    This study aimed to investigate the correlation between upper airway dimensions and hyoid bone position in Chinese adolescents based on cone beam computed tomography (CBCT) images. CBCT images from a total of 254 study subjects were included. The upper airway and hyoid bone parameters were measured by Materialism's interactive medical image control system (MIMICS) v.16.01 (Materialise, Leuven, Belgium). The airway dimensions were evaluated in terms of volume, cross-sectional area (CSA), mean CSA, length, anteroposterior dimension of the cross-section (AP), lateral dimension of the cross-section (LAT), and LAT/AP ratio. The hyoid bone position was evaluated using eight linear parameters and two angular parameters. Facial characteristics were evaluated using three linear parameters and three angular parameters. Most hyoid bone position parameters (especially the distance between the hyoid bone and hard palate) were significantly associated with most airway dimension parameters. Significant correlations were also observed between the different facial characteristic parameters and hyoid bone position parameters. Most airway dimension parameters showed significant correlations with linear facial parameters, but they displayed significant correlations with only a few angular facial parameters. These findings provide an understanding of the static relationship between the hyoid bone position and airway dimensions, which may serve as a reference for surgeons before orthodontic or orthognathic surgery.

  9. The cross-sectional size and shape of human terminal scalp hair.

    PubMed

    Hutchinson, P E; Thompson, J R

    1997-02-01

    Change in size of the hair shaft with distance form the scalp has been investigated, using a rotatory profile method of diameter measurement, in terminal human scalp hair of long-haired young Caucasian women. As the whole length of hairs having completed anagen are rarely found intact, two types of hair were investigated: those including segments produced at the onset of anagen ('anagen hairs'), and those including segments produced at the end of anagen ('telogen hairs'). In addition, a method of determining the cause of any size variation has been described and employed. Changes were found in the major axis of the hair cross-section, cross-sectional area and ellipticity with distance from the scalp, while the minor cross-sectional axis remained constant. It was established that these changes were the result of intrafollicular rather than extrafollicular mechanisms. Finally, a composite picture of the cross-sectional size and shape of the 'average' whole anagen hair of the study has been constructed. From the distal tip towards the scalp for approximately 6-8 cm, there was an abrupt increase in size, representing a starting-up phase of early anagen. Following this, the hair was at its greatest cross-sectional size and ellipticity which then progressively decreased through anagen (20% decrease for cross-sectional area and 13% for ellipticity). In contrast, the minor axis of the hair cross-section, remained constant throughout anagen. The hair was not therefore a uniformly sized cylinder. It was approximately spear-shaped, being broadened out in one plane distally where it was more elliptical. Subsequently as anagen progressed the hair shaft became smaller and more circular.

  10. Cross Section Sensitivity and Propagated Errors in HZE Exposures

    NASA Technical Reports Server (NTRS)

    Heinbockel, John H.; Wilson, John W.; Blatnig, Steve R.; Qualls, Garry D.; Badavi, Francis F.; Cucinotta, Francis A.

    2005-01-01

    It has long been recognized that galactic cosmic rays are of such high energy that they tend to pass through available shielding materials resulting in exposure of astronauts and equipment within space vehicles and habitats. Any protection provided by shielding materials result not so much from stopping such particles but by changing their physical character in interaction with shielding material nuclei forming, hopefully, less dangerous species. Clearly, the fidelity of the nuclear cross-sections is essential to correct specification of shield design and sensitivity to cross-section error is important in guiding experimental validation of cross-section models and database. We examine the Boltzmann transport equation which is used to calculate dose equivalent during solar minimum, with units (cSv/yr), associated with various depths of shielding materials. The dose equivalent is a weighted sum of contributions from neutrons, protons, light ions, medium ions and heavy ions. We investigate the sensitivity of dose equivalent calculations due to errors in nuclear fragmentation cross-sections. We do this error analysis for all possible projectile-fragment combinations (14,365 such combinations) to estimate the sensitivity of the shielding calculations to errors in the nuclear fragmentation cross-sections. Numerical differentiation with respect to the cross-sections will be evaluated in a broad class of materials including polyethylene, aluminum and copper. We will identify the most important cross-sections for further experimental study and evaluate their impact on propagated errors in shielding estimates.

  11. Modeling elastic momentum transfer cross-sections from mobility data

    NASA Astrophysics Data System (ADS)

    Nikitović, Ž. D.; Stojanović, V. D.; Raspopović, Z. M.

    2016-04-01

    In this letter we present a new method to simply obtain the elastic momentum transfer cross-section which predicts a maximum of reduced mobility and its sensitivity to the temperature variation at low energies. We first determined the transport cross-section which resembles mobility data for similar closed-shell systems by using the Monte Carlo method. Second, we selected the most probable reactive processes and compiled cross-sections from experimental and theoretical data. At the end, an elastic momentum transfer cross-section is obtained by subtracting the compiled cross-sections from the momentum transfer cross-section, taking into account the effects of the angular scattering distributions. Finally, the cross-section set determined in such a way is used as an input in a final Monte Carlo code run, to calculate the flux and bulk reduced mobility for Ne+ + CF4 which were discussed as functions of the reduced electric field E/N (N is the gas density) for the temperature T = 300 K.

  12. Electron impact rotationally elastic total cross section for formamide

    NASA Astrophysics Data System (ADS)

    Vinodkumar, Minaxi; Limbachiya, Chetan; Desai, Hardik; Vinodkumar, P. C.

    2014-09-01

    This paper reports computational results of the total cross sections for electron impact on formamide (HCONH2) over a wide range of energies from 0.01 eV to 5 keV. Total cross sections over such a wide range are reported for the first time as the earlier reported data is up to maximum of 12 eV. Below ionization threshold of the target, we performed ab initio calculations using UK molecular R-Matrix code within static, exchange plus polarization (SEP), and close coupling approximations. Twenty eight target states are included in close coupling formalism. Total 350 channels and 2410 configuration state functions are included in the calculations. We observe a π* shape resonance at 3.41 eV and a σ* resonance at 15.3 eV as against similar resonances reported at 3.77 eV and 14.9 eV, respectively, by Goumans et al. [J. Chem. Theory Comput. 5, 217 (2009)] using SEP model. The cross sections at higher energies are evaluated using the spherical complex optical potential formalism. The two methods are found to be consistent with a smooth cross over at 18 eV. The vertical excitation energies, electronic excitation cross sections, differential cross sections, momentum transfer, and total cross sections are computed. In absence of experimental data, we compared our computed total cross sections with available other theoretical results.

  13. Electron impact rotationally elastic total cross section for formamide

    SciTech Connect

    Vinodkumar, Minaxi; Limbachiya, Chetan; Desai, Hardik Vinodkumar, P. C.

    2014-09-28

    This paper reports computational results of the total cross sections for electron impact on formamide (HCONH₂) over a wide range of energies from 0.01 eV to 5 keV. Total cross sections over such a wide range are reported for the first time as the earlier reported data is up to maximum of 12 eV. Below ionization threshold of the target, we performed ab initio calculations using UK molecular R-Matrix code within static, exchange plus polarization (SEP), and close coupling approximations. Twenty eight target states are included in close coupling formalism. Total 350 channels and 2410 configuration state functions are included in the calculations. We observe a π* shape resonance at 3.41 eV and a σ* resonance at 15.3 eV as against similar resonances reported at 3.77 eV and 14.9 eV, respectively, by Goumans et al. [J. Chem. Theory Comput. 5, 217 (2009)] using SEP model. The cross sections at higher energies are evaluated using the spherical complex optical potential formalism. The two methods are found to be consistent with a smooth cross over at 18 eV. The vertical excitation energies, electronic excitation cross sections, differential cross sections, momentum transfer, and total cross sections are computed. In absence of experimental data, we compared our computed total cross sections with available other theoretical results.

  14. Accessing completeness of pregnancy, delivery, and death registration by Accredited Social Health Activists [ASHA] in an innovative mHealth project in the tribal areas of Gujarat: A cross-sectional study

    PubMed Central

    Modi, D; Patel, J; Desai, S; Shah, P

    2016-01-01

    Background: The Innovative Mobile-phone Technology for Community Health Operation (ImTeCHO) is a mobile-phone application that helps Accredited Social Health Activists (ASHAs) in complete registration through the strategies employed during implementation that is linking ASHAs’ incentives to digital records, regular feedback, onsite data entry, and demand generation among beneficiaries. Objective: To determine the proportion of pregnancies, deliveries, and infant deaths (events) being registered through the ImTeCHO application against actual number of events in a random sample of villages. Materials and Methods: Five representative villages were randomly selected from the ImTeCHO project area in the tribal areas of Gujarat, India to obtain the required sample of 98 recently delivered women. A household survey was done in the entire villages to enumerate each family and create a line-listing of events since January 2014; the line-listing was compared with list of women registered through the ImTeCHO application. The proportion of events being registered through the ImTeCHO application was compared against the actual number of events to find sensitivity of the ImTeCHO application. Result: A total of 844 families were found during household enumeration. Out of actual line-listing of pregnancies (N = 39), deliveries (N = 102), and infant deaths (N = 5) found during household enumeration, 38 (97.43%), 101 (99.01%), and 5 (100%) were registered by ASHAs through the ImTeCHO application. Conclusion: The use of mobile-phone technology and strategies applied during the ImTeCHO implementation should be upscaled to supplement efforts to improve the completeness of registration. PMID:27241808

  15. Review of electron impact excitation cross sections for copper atom

    SciTech Connect

    Winter, N.W.; Hazi, A.U.

    1982-02-01

    Excitation of atomic copper by electron impact plays an important role in the copper vapor laser and accurate cross sections are needed for understanding and modeling laser performance. During the past seven years, there have been several attempts to normalize the relative elastic and inelastic cross sections measured by Trajmar and coworkers. However, each of these efforts have yielded different cross sections, and the uncertainty in the correct normalization of the data has been a source of confusion and concern for the kinetic modeling efforts. This difficulty has motivated us to review previous work on the electron impact excitation of copper atom and to perform new calculations of the inelastic cross sections using the impact parameter method. In this memorandum we review the previous attempts to normalize the experimental data and provide a critical assessment of the accuracy of the resulting cross sections. We also present new theoretical cross sections for the electron impact excitation of the /sup 2/S ..-->.. /sup 2/P/sup 0/ and /sup 2/S ..-->.. /sup 2/D transitions in copper. When the experimental cross sections are renormalized to the results of the impact parameter calculations, they are a factor of three smaller than those published in the latest paper of Trajmar et. al. At impact energies above 60 eV the excitation cross sections obtained with the impact parameter method agree well with the results of the very recent, unpublished, close-coupling calculations of Henry. This agreement suggests that the present normalization of the experimental cross sections is probably the most reliable one obtained to date.

  16. Electron impact ionization cross sections of beryllium-tungsten clusters*

    NASA Astrophysics Data System (ADS)

    Sukuba, Ivan; Kaiser, Alexander; Huber, Stefan E.; Urban, Jan; Probst, Michael

    2016-01-01

    We report calculated electron impact ionization cross sections (EICSs) of beryllium-tungsten clusters, BenW with n = 1,...,12, from the ionization threshold to 10 keV using the Deutsch-Märk (DM) and the binary-encounter-Bethe (BEB) formalisms. The positions of the maxima of DM and BEB cross sections are mostly close to each other. The DM cross sections are more sensitive with respect to the cluster size. For the clusters smaller than Be4W they yield smaller cross sections than BEB and vice versa larger cross sections than BEB for clusters larger than Be6W. The maximum cross section values for the singlet-spin groundstate clusters range from 7.0 × 10-16 cm2 at 28 eV (BeW) to 54.2 × 10-16 cm2 at 43 eV (Be12W) for the DM cross sections and from 13.5 × 10-16 cm2 at 43 eV (BeW) to 38.9 × 10-16 cm2 at 43 eV (Be12W) for the BEB cross sections. Differences of the EICSs in different isomers and between singlet and triplet states are also explored. Both the DM and BEB cross sections could be fitted perfectly to a simple expression used in modeling and simulation codes in the framework of nuclear fusion research. Contribution to the Topical Issue "Atomic Cluster Collisions (7th International Symposium)", edited by Gerardo Delgado Barrio, Andrey Solov'Yov, Pablo Villarreal, Rita Prosmiti.Supplementary material in the form of one pdf file available from the Journal web page at http://dx.doi.org/10.1140/epjd/e2015-60583-7

  17. Overweight among students aged 11–15 years and its relationship with breakfast, area of residence and parents’ education: results from the Italian HBSC 2010 cross-sectional study

    PubMed Central

    2014-01-01

    Background The international increase in overweight and obesity among children and adolescents over the past three decades confirms that childhood obesity is a global ‘epidemic’. The World Health Organization considers childhood obesity to be a major public health concern. Childhood obesity is associated with cardiovascular, endocrine, musculoskeletal and gastrointestinal complications, and may have psycho-social consequences. The aim of this paper is to examine overweight (including obesity) prevalence and its association with geographic area of residence, parental education and daily breakfast consumption in Italian students aged 11–15 yrs. Methods A nationally representative sample of 11–15 year old students from 20 Italian Regions (Italian Health Behaviour in School-aged Children 2010-HBSC) was randomly selected (2,504 schools and 77,113 students). Self-reported anonymous questionnaires, prepared by the international HBSC network, were used to collect the data. BMI was calculated using self-reported weight and height and the International Obesity Task Force cut-offs. Multiple logistic regressions were performed to assess the relationship between the risk of overweight and parental education, area of residence and breakfast consumption in each age group and gender. Results Boys were more likely to be overweight or obese than girls (28.1% vs. 18.9% at 11 yrs-old, 24.8% vs. 16.5% at 13 yrs and 25.4 vs. 11.8% at 15 yrs). The prevalence of overweight and obesity was lower among the older girls. Overweight and obesity rates increased from the North of Italy to the South in both boys and girls and in all age groups. Boys 11-15 yrs living in southern Italy had an OR=2.05 (1.77-2.38) and girls 2.04 (95% CI 1.70-2.44) for overweight (including obesity) compared with those living in the North. Parent’s low educational level and no daily breakfast consumption were also associated with overweight including obesity (p<0.05). Conclusion The prevalence of

  18. Regional structural cross sections, mid-permian to quaternary strata, Texas Panhandle and Eastern New Mexico

    SciTech Connect

    McGookey, D.A.; Gustavson, T.C.; Hoadley, A.D.

    1989-01-01

    Twelve regional cross sections (with text) of the Palo Duro, Dalhart, and Anadarko Basins illustrating the tabular geometry of Permian evaporite beds, areas where salt has been lost by dissolution, and the effects of dissolution-induced subsidence on Permian and post-Permian strata. The authors identify areas of dissolution beneath the High Plains, the Caprock Escarpment, the Rolling Plains, the Pecos Plains, and along the Canadian River valley. The cross sections are printed at a vertical scale of 1 inch equals 400 feet and a horizontal scale of 1 inch equals approximately 8 miles and were constructed using geophysical logs, sample logs, and surficial geologic data.

  19. Top quark pair production cross section at Tevatron

    SciTech Connect

    Shary, V.; /DAPNIA, Saclay

    2009-05-01

    An overview of the recent measurements of the top antitop quark pair production cross section in proton antiproton collisions at {radical}s = 1.96 TeV in lepton + jets and dilepton final states is presented. These measurements are based on 1-2.8 fb{sup -1} of data collected with the D0 and CDF experiments at the Fermilab Tevatron collider. The cross section is measured with a precision close to 8 % and found to be compatible with the standard model prediction. Interpretations of the cross-section measurements for charge higgs search and for top quark mass measurement are also discussed.

  20. Relative charge transfer cross section from Rb (4d)

    NASA Astrophysics Data System (ADS)

    Shah, M. H.; Camp, H. A.; Trachy, M. L.; Fléchard, X.; Gearba, M. A.; Nguyen, H.; Brédy, R.; Lundeen, S. R.; Depaola, B. D.

    2005-08-01

    Relative charge transfer cross section measurements for the excited state Rb(4d) with 7keV Na+ is reported. The specific channels reported are Na++Rb(4d5/2)→Na(nl)+Rb+ , where the dominant transfer cross sections channels were nl=3d and 4s . Using a combination of a magneto-optical trap and recoil ion momentum spectroscopy (MOTRIMS methodology), the cross sections were measured relative to the previously studied Na++Rb(5s,5p) systems at the same collision energy.

  1. Antinucleus-Nucleus Cross Sections Implemented in Geant4

    SciTech Connect

    Uzhinsky, V.; Apostolakis, J.; Galoyan, A.; Folger, G.; Grichine, V.M.; Ivanchenko, V.N.; Wright, D.H.; /SLAC

    2012-04-26

    Cross sections of antinucleus ({bar p}, {bar d}, {bar t}, {sup 3}{ovr He}, {sup 4}{ovr He}) interactions with nuclei in the energy range 100 MeV/c to 1000 GeV/c per antinucleon are calculated in the Glauber approximation which provides good description of all known {bar p}Across sections. The results were obtained using a new parameterization of the total and elastic {bar p}p cross sections. Simple parameterizations of the antinucleus-nucleus cross sections are proposed for use in estimating the efficiency of antinucleus detection and tracking in cosmic rays and accelerator experiments. These parameterizations are implemented in the Geant4 toolkit.

  2. Actinide neutron-induced fission cross section measurements at LANSCE

    SciTech Connect

    Tovesson, Fredrik K; Laptev, Alexander B; Hill, Tony S

    2010-01-01

    Fission cross sections of a range of actinides have been measured at the Los Alamos Neutron Science Center (LANSCE) in support of nuclear energy applications in a wide energy range from sub-thermal energies up to 200 MeV. A parallel-plate ionization chamber are used to measure fission cross sections ratios relative to the {sup 235}U standard while incident neutron energies are determined using the time-of-flight method. Recent measurements include the {sup 233,238}U, {sup 239-242}Pu and {sup 243}Am neutron-induced fission cross sections. Obtained data are presented in comparison with ex isting evaluations and previous data.

  3. Relative charge transfer cross section from Rb(4d)

    SciTech Connect

    Shah, M.H.; Camp, H.A.; Trachy, M.L.; De Paola, B.D.; Flechard, X.; Gearba, M.A.; Nguyen, H.; Bredy, R.; Lundeen, S.R.

    2005-08-15

    Relative charge transfer cross section measurements for the excited state Rb(4d) with 7 keV Na{sup +} is reported. The specific channels reported are Na{sup +}+Rb(4d{sub 5/2}){yields}Na(nl)+Rb{sup +}, where the dominant transfer cross sections channels were nl=3d and 4s. Using a combination of a magneto-optical trap and recoil ion momentum spectroscopy (MOTRIMS methodology), the cross sections were measured relative to the previously studied Na{sup +}+Rb(5s,5p) systems at the same collision energy.

  4. A Potential Synergy between Incomplete Arsenic Methylation Capacity and Demographic Characteristics on the Risk of Hypertension: Findings from a Cross-Sectional Study in an Arsenic-Endemic Area of Inner Mongolia, China

    PubMed Central

    Li, Yongfang; Wang, Da; Li, Xin; Zheng, Quanmei; Sun, Guifan

    2015-01-01

    Inefficient arsenic methylation capacity has been associated with various health hazards induced by arsenic. In this study, we aimed to explore the interaction effect of lower arsenic methylation capacity with demographic characteristics on hypertension risk. A total of 512 adult participants (126 hypertension subjects and 386 non-hypertension subjects) residing in an arsenic-endemic area in Inner Mongolia, China were included. Urinary levels of inorganic arsenic (iAs), monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA) were measured for all subjects. The percentage of urinary arsenic metabolites (iAs%, MMA%, and DMA%), primary methylation index (PMI) and secondary methylation index (SMI) were calculated to assess arsenic methylation capacity of individuals. Results showed that participants carrying a lower methylation capacity, which is characterized by lower DMA% and SMI, have a higher risk of hypertension compared to their corresponding references after adjusting for multiple confounders. A potential synergy between poor arsenic methylation capacity (higher MMA%, lower DMA% and SMI) and older age or higher BMI were detected. The joint effects of higher MMA% and lower SMI with cigarette smoking also suggest some evidence of synergism. The findings of present study indicated that inefficient arsenic methylation capacity was associated with hypertension and the effect might be enhanced by certain demographic factors. PMID:25837203

  5. Awareness and management of chronic disease, insurance status, and health professional shortage areas in the REasons for Geographic And Racial Differences in Stroke (REGARDS): a cross-sectional study

    PubMed Central

    2012-01-01

    Background Limited financial and geographic access to primary care can adversely influence chronic disease outcomes. We examined variation in awareness, treatment, and control of hypertension, diabetes, and hyperlipidemia according to both geographic and financial access to care. Methods We analyzed data on 17,458 participants in the REasons for Geographic And Racial Differences in Stroke (REGARDS) study with either hypertension, hyperlipidemia, or diabetes and living in either complete Health Professional Shortage Area (HPSA) counties or non-HPSA counties in the U.S. All analyses were stratified by insurance status and adjusted for sociodemographics and health behaviors. Results 2,261 residents lived in HPSA counties and 15,197 in non-HPSA counties. Among the uninsured, HPSA residents had higher awareness of both hypertension (adjusted OR 2.30, 95% CI 1.08, 4.89) and hyperlipidemia (adjusted OR 1.50, 95% CI 1.01, 2.22) compared to non-HPSA residents. Also among the uninsured, HPSA residents with hypertension had lower blood pressure control (adjusted OR 0.45, 95% CI 0.29, 0.71) compared with non-HPSA residents. Similar differences in awareness and control according to HPSA residence were absent among the insured. Conclusions Despite similar or higher awareness of some chronic diseases, uninsured HPSA residents may achieve control of hypertension at lower rates compared to uninsured non-HPSA residents. Federal allocations in HPSAs should target improved quality of care as well as increasing the number of available physicians. PMID:22818296

  6. In situ oil shale retort with a generally T-shaped vertical cross section

    DOEpatents

    Ricketts, Thomas E.

    1981-01-01

    An in situ oil shale retort is formed in a subterranean formation containing oil shale. The retort contains a fragmented permeable mass of formation particles containing oil shale and has a production level drift in communication with a lower portion of the fragmented mass for withdrawing liquid and gaseous products of retorting during retorting of oil shale in the fragmented mass. The principal portion of the fragmented mass is spaced vertically above a lower production level portion having a generally T-shaped vertical cross section. The lower portion of the fragmented mass has a horizontal cross sectional area smaller than the horizontal cross sectional area of the upper principal portion of the fragmented mass above the production level.

  7. 8. VIEW OF CROSS SECTION OF THE EASTERNMOST WALL SEGMENT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. VIEW OF CROSS SECTION OF THE EASTERNMOST WALL SEGMENT THAT SHOWS THE TRENCHING AND 1960 PIPELINE CORRIDOR BETWEEN THE WALL SEGMENTS, LOOKING WEST-NORTHWEST - Rock Wall, North side of Battle Creek Canyon, Shingletown, Shasta County, CA

  8. Radiative neutron capture cross sections on 176Lu at DANCE

    NASA Astrophysics Data System (ADS)

    Roig, O.; Jandel, M.; Méot, V.; Bond, E. M.; Bredeweg, T. A.; Couture, A. J.; Haight, R. C.; Keksis, A. L.; Rundberg, R. S.; Ullmann, J. L.; Vieira, D. J.

    2016-03-01

    The cross section of the neutron capture reaction 176Lu(n ,γ ) has been measured for a wide incident neutron energy range with the Detector for Advanced Neutron Capture Experiments at the Los Alamos Neutron Science Center. The thermal neutron capture cross section was determined to be (1912 ±132 ) b for one of the Lu natural isotopes, 176Lu. The resonance part was measured and compared to the Mughabghab's atlas using the R -matrix code, sammy. At higher neutron energies the measured cross sections are compared to ENDF/B-VII.1, JEFF-3.2, and BRC evaluated nuclear data. The Maxwellian averaged cross sections in a stellar plasma for thermal energies between 5 keV and 100 keV were extracted using these data.

  9. Fluctuations of cross sections seen in cosmic ray data

    SciTech Connect

    Wilk, G. ); Wlodarczyk, Z. )

    1994-08-01

    We argue that the unexpected nonexponential behavior of some cosmic ray data is just a manifestation of cross section fluctuations discussed recently in the literature and observed in nuclear collisions and in diffraction dissociation experiments on accelerators.

  10. 36. CROSS SECTIONAL VIEW OF ORIGINAL HORSE MESA DAM POWER ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    36. CROSS SECTIONAL VIEW OF ORIGINAL HORSE MESA DAM POWER PLANT, LOOKING NORTH. ONLY TWO OF THE THREE UNITS ARE VISIBLE - Horse Mesa Dam, Salt River, 65 miles East of Phoenix, Phoenix, Maricopa County, AZ

  11. 20. CROSS SECTIONAL VIEW OF HORSE MESA, SHOWING RIGHT SPILLWAY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    20. CROSS SECTIONAL VIEW OF HORSE MESA, SHOWING RIGHT SPILLWAY SUPERSTRUCTURE AND CONCRETE PLACEMENT LINES August 2, 1927 - Horse Mesa Dam, Salt River, 65 miles East of Phoenix, Phoenix, Maricopa County, AZ

  12. On the cyclo-synchrotron cross-section

    NASA Astrophysics Data System (ADS)

    Gliozzi, M.; Bodo, G.; Ghisellini, G.; Trussoni, E.

    1996-06-01

    The study of the synchrotron and cyclotron absorption processes and their relative cross-sections, recently analysed by Ghisellini & Svensson, is extended to the case of photons propagating along the direction of the magnetic field. In the relativistic regime we follow a quantum approach, which requires first the derivation of the particle emissivity for the assumed configuration. The expression for the cross-section coincides with that obtained through a classical treatment of the problem in the non-relativistic regime. In the frequency range where absorption is important, the cross-section is larger than the Thomson cross-section by several orders of magnitude, implying a strong coupling between radiation and magnetized plasma. The possible atrophysical implications of this process are briefly discussed; in particular, in a magnetized plasma the Eddington luminosity for synchrotron interaction can be much lower than the standard value.

  13. Photocopy of longitudinal, cross sections and roof plan of the ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of longitudinal, cross sections and roof plan of the C.B. & Q. R.R. roundhouse and locomotive shops. June 1980. - Chicago, Burlington & Quincy Railroad, Roundhouse & Shops, Broadway & Spring Streets, Aurora, Kane County, IL

  14. Cross Sections for K-Shell Ionization by Electron Impact

    NASA Astrophysics Data System (ADS)

    Santos, J. P.; Parente, F.; Kim, Yong-Ki

    2001-05-01

    The formula for the total ionization cross section by electron impact based on the Binary-Encounter-Bethe (BEB) model, which has been very successful in reproducing electron-impact total ionization cross sections for atoms(Y.-K. Kim and M.E. Rudd, Phys. Rev A 50), 3954 (1994), was extended to provides reliable inner-shell ionization cross sections from the threshold to relativistic incident electron energies with simple input data for the target inner shell: the binding energy, the orbital kinetic energy and the electron occupation number(Y.-K. Kim, J. P. Santos, and F. Parente, Phys. Rev. A, 62), 052710 (2000). A comparison between the nonrelativistic BEB and the relativistic BEB (RBEB) K-shell ionization cross sections by electron impact for the carbon, argon, nickel, niobium, and silver atoms and the available experimental and theoretical data will be presented at the conference.

  15. 4. DETAIL VIEW OF CROSS SECTION OF STRUCTURE, SHOWING EXTERIOR ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. DETAIL VIEW OF CROSS SECTION OF STRUCTURE, SHOWING EXTERIOR FACINGS LINED WITH RUBBLE BACKING AND EARTH INFILL, LOOKING EAST - Rock Wall, North side of Battle Creek Canyon, Shingletown, Shasta County, CA

  16. Modeling ionization cross sections: Two decades of dreams come true

    NASA Astrophysics Data System (ADS)

    Kim, Yong-Ki

    1996-03-01

    Modeling of differential and total ionization cross sections by electron impact is reviewed. A new theoretical model that does not depend on any empirical or arbitrary parameters is described. The prototype of this new model was proposed by Rudd and was originally based on the binary-encounter theory. The model has been improved by replacing a part of the binary-encounter theory with the dipole contribution as prescribed by the Bethe theory. The current model, henceforth referred to as the binary-encounter-dipole (BED) model, reproduces known singly differential and total ionization cross sections for small atoms and molecules accurately. The possibility of extending the BED theory to doubly differential cross sections as well as to proton-impact ionization cross sections is discussed.

  17. 15. Power plant elevations and cross sections, sheet 64 of ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    15. Power plant elevations and cross sections, sheet 64 of 130 - Naval Air Station Fallon, Power Plant, 800 Complex, off Carson Road near intersection of Pasture & Berney Roads, Fallon, Churchill County, NV

  18. Theoretical Studies on Photoionization Cross Sections of Solid Gold

    NASA Astrophysics Data System (ADS)

    Ma, Xiao-Guang; Sun, Wei-Guo; Cheng, Yan-Song

    2005-01-01

    Accurate expression for photoabsorption (photoionization) cross sections of high density system proposed recently is used to study the photoionization of solid gold. The results show that the present theoretical photoionization cross sections have good agreement both in structure and in magnitude with the experimental results of gold crystal. The studies also indicate that both the real part ε' and the imaginary part ε'' of the complex dielectric constant ε, and the dielectric influence function of a nonideal system have rich structures in low energy side with a range about 50 eV, and suggest that the influence of particle interactions of surrounding particles with the photoionized particle on the photoionization cross sections can be easily investigated using the dielectric influence function. The electron overlap effects are suggested to be implemented in the future studies to improve the accuracy of theoretical photoionization cross sections of a solid system.

  19. Electron-Impact Total Ionization Cross Sections of Hydrocarbon Ions

    PubMed Central

    Irikura, Karl K.; Kim, Yong-Ki; Ali, M. A.

    2002-01-01

    The Binary-Encounter-Bethe (BEB) model for electron-impact total ionization cross sections has been applied to CH2+, CH3+, CH4+, C2H2+, C2H4+, C2H6+ and H3O+. The cross sections for the hydrocarbon ions are needed for modeling cool plasmas in fusion devices. No experimental data are available for direct comparison. Molecular constants to generate total ionization cross sections at arbitrary incident electron energies using the BEB formula are presented. A recent experimental result on the ionization of H3O+ is found to be almost 1/20 of the present theory at the cross section peak. PMID:27446718

  20. 28. CROSS SECTION OF A RECTANGULAR COKE OVEN SHOWING THE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    28. CROSS SECTION OF A RECTANGULAR COKE OVEN SHOWING THE INTERNAL STRUCTURE OF THE OVEN. - Tower Hill No. 2 Mine, Approximately 0.47 mile Southwest of intersection of Stone Church Road & Township Route 561, Hibbs, Fayette County, PA

  1. 12. CLOSEUP VIEW OF CROSS SECTION OF SPILLWAY FIFTY FEET ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. CLOSE-UP VIEW OF CROSS SECTION OF SPILLWAY FIFTY FEET FROM LAKESHORE, SHOWING REMAINS OF SPILLWAY TIMBERS, LOOKING WEST - Three Bears Lake & Dams, North of Marias Pass, East Glacier Park, Glacier County, MT

  2. Differential cross sections of positron–hydrogen collisions

    NASA Astrophysics Data System (ADS)

    Rong-Mei, Yu; Chun-Ying, Pu; Xiao-Yu, Huang; Fu-Rong, Yin; Xu-Yan, Liu; Li-Guang, Jiao; Ya-Jun, Zhou

    2016-07-01

    We make a detailed study on the angular differential cross sections of positron–hydrogen collisions by using the momentum-space coupled-channels optical (CCO) method for incident energies below the H ionization threshold. The target continuum and the positronium (Ps) formation channels are included in the coupled-channels calculations via a complex equivalent-local optical potential. The critical points, which show minima in the differential cross sections, as a function of the scattering angle and the incident energy are investigated. The resonances in the angular differential cross sections are reported for the first time in this energy range. The effects of the target continuum and the Ps formation channels on the different cross sections are discussed. Project supported by the Nanyang Normal University Science Foundation of China (Grant No. ZX2013017) and the National Natural Science Foundation of China (Grant Nos. 11174066, 61306007, and U1304114).

  3. Photocopy of "sheet 6 of 8" showing cross section of ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of "sheet 6 of 8" showing cross section of house, front elevation, fire finder stand, hip roof cap, and shiplap roof sheathing. - Badger Mountain Lookout, .125 mile northwest of Badger Mountain summit, East Wenatchee, Douglas County, WA

  4. Excited state cross sections for Er-doped glasses

    NASA Astrophysics Data System (ADS)

    Zemon, Stanley A.; Lambert, Gary M.; Miniscalco, William J.; Davies, Richard W.; Hall, Bruce T.; Folweiler, Robert C.; Wei, Ta-Sheng; Andrews, Leonard J.; Singh, Mahendra P.

    1991-01-01

    Excited-state-absorption (ESA) cross sections were determined for the region between 760 and 900 nm for Er-doped fluorophosphate phosphate and silicate glasses. Measurements were performed on multimode fibers pumping at 647 nm with powers 1 . 5 Wto invert the population into the saturation regime. Over much of the 800-nm band ground-state-absorption (GSA) cross sections are equal to or greater than ESA cross sections. For comparison ESA was also measured for singlemode Al/P-doped silica fiber. The cross sections were incorporated into an amplifier model and the phosphate and fluorophosphate glasses were found to provide higher gain than silica for pumping in the 800-nm band. Photoexcited fluorozirconates were found to have substantial populations in the first four excited states and ESA transitions originating from these states are identified.

  5. Proximal femoral diaphyseal cross-sectional geometry in Orrorin tugenensis.

    PubMed

    Bleuze, M

    2012-06-01

    Functional adaptations in femora attributed to Orrorin tugenensis provide a unique opportunity to examine locomotor behavior very early in the hominin lineage. This study examines relative cortical thickness, cortical area (CA) relative to the polar moment of area (J), and J relative to femoral head superoinferior diameter (FHD) in the proximal femur of O. tugenensis (BAR 1002'00 and BAR 1003'00), and compares patterns in this early hominin with those in a sample of modern humans (N=31), Plio-Pleistocene fossil hominins (N=8), Pan troglodytes troglodytes (N=13), and Pan paniscus (N=3). Relative cortical thickness and CA relative to J in the proximal femur of O. tugenensis are comparable to patterns generally found in other fossil hominins. Proximal femoral diaphyseal J relative to FHD in BAR 1002'00 is similar to patterns found in fossil hominins typically attributed to a non-Homo genus (i.e. SK 82, SK 97, and KNM-ER 738). Cross-sectional geometric patterns in the proximal femur of Orrorin are not unlike those generally found in australopithecines and fossil Homo. While the results of this study cannot confirm unequivocally that Orrorin was an obligate biped, a mode of locomotion comparable to that proposed for australopithecines cannot be ruled out. PMID:22609080

  6. Proximal femoral diaphyseal cross-sectional geometry in Orrorin tugenensis.

    PubMed

    Bleuze, M

    2012-06-01

    Functional adaptations in femora attributed to Orrorin tugenensis provide a unique opportunity to examine locomotor behavior very early in the hominin lineage. This study examines relative cortical thickness, cortical area (CA) relative to the polar moment of area (J), and J relative to femoral head superoinferior diameter (FHD) in the proximal femur of O. tugenensis (BAR 1002'00 and BAR 1003'00), and compares patterns in this early hominin with those in a sample of modern humans (N=31), Plio-Pleistocene fossil hominins (N=8), Pan troglodytes troglodytes (N=13), and Pan paniscus (N=3). Relative cortical thickness and CA relative to J in the proximal femur of O. tugenensis are comparable to patterns generally found in other fossil hominins. Proximal femoral diaphyseal J relative to FHD in BAR 1002'00 is similar to patterns found in fossil hominins typically attributed to a non-Homo genus (i.e. SK 82, SK 97, and KNM-ER 738). Cross-sectional geometric patterns in the proximal femur of Orrorin are not unlike those generally found in australopithecines and fossil Homo. While the results of this study cannot confirm unequivocally that Orrorin was an obligate biped, a mode of locomotion comparable to that proposed for australopithecines cannot be ruled out.

  7. Thermal neutron capture cross sections of tellurium isotopes

    SciTech Connect

    Tomandl, I.; Honzatko, J.; von Egidy, T.; Wirth, H.-F.; Belgya, T.; Lakatos, M.; Szentmiklosi, L.; Revay, Zs.; Molnar, G.L.; Firestone, R.B.; Bondarenko, V.

    2004-03-01

    New values for thermal neutron capture cross sections of the tellurium isotopes 122Te, 124Te, 125Te, 126Te, 128Te, and 130Te are reported. These values are based on a combination of newly determined partial g-ray cross sections obtained from experiments on targets contained natural Te and gamma intensities per capture of individual Te isotopes. Isomeric ratios for the thermal neutron capture on the even tellurium isotopes are also given.

  8. Modelling of reaction cross sections and prompt neutron emission

    NASA Astrophysics Data System (ADS)

    Hambsch, F.-J.; Tudora, A.; Oberstedt, S.

    2010-10-01

    Accurate nuclear data concerning reaction cross sections and the emission of prompt fission neutrons (i.e. multiplicity and spectra) as well as other fission fragment data are of great importance for reactor physics design, especially for the new Generation IV nuclear energy systems. During the past years for several actinides (238U(n, f) and 237Np(n, f)) both the reaction cross sections and prompt neutron multiplicities and spectra have been calculated within the frame of the EFNUDAT project.

  9. Top Quark Pair Production Cross Section at the Tevatron

    SciTech Connect

    Peters, Reinhild Yvonne

    2015-09-25

    The top quark, discovered in 1995 by the CDF and D0 collaborations at the Tevatron proton antiproton collider at Fermilab, has undergone intense studies in the last 20 years. Currently, CDF and D0 converge on their measurements of top-antitop quark production cross sections using the full Tevatron data sample. In these proceedings, the latest results on inclusive and differential measurements of top-antitop quark production cross sections at the Tevatron are reported.

  10. Absorption cross sections of the ClO dimer

    NASA Technical Reports Server (NTRS)

    Huder, K. J.; DeMore, W. B.

    1995-01-01

    The absorption cross sections of the ClO dimer, ClOOCl, are important to the photochemistry of ozone depletion in the Antarctic. In this work, new measurements were made of the dimer cross sections at 195 K. the results yield somewhat lower values in the long wavelength region, compared to those currently recommended in the NASA data evaluation (JPL 94-26). The corresponding solar photodissociation rates in the Antarctic are reduced by about 40%.

  11. Updated ozone absorption cross section will reduce air quality compliance

    NASA Astrophysics Data System (ADS)

    Sofen, E. D.; Evans, M. J.; Lewis, A. C.

    2015-12-01

    Photometric ozone measurements rely upon an accurate value of the ozone absorption cross section at 253.65 nm. This has recently been re-evaluated by Viallon et al. (2015) as 1.8 % smaller than the accepted value (Hearn, 1961) used for the preceding 50 years. Thus, ozone measurements that applied the older cross section systematically underestimate the amount of ozone in air. We correct the reported historical surface data from North America and Europe and find that this modest change in cross section has a significant impact on the number of locations that are out of compliance with air quality regulations if the air quality standards remain the same. We find 18, 23, and 20 % increases in the number of sites that are out of compliance with current US, Canadian, and European ozone air quality health standards for the year 2012. Should the new cross-section value be applied, it would impact attainment of air quality standards and compliance with relevant clean air acts, unless the air quality target values themselves were also changed proportionately. We draw attention to how a small change in gas metrology has a global impact on attainment and compliance with legal air quality standards. We suggest that further laboratory work to evaluate the new cross section is needed and suggest three possible technical and policy responses should the new cross section be adopted.

  12. Updated ozone absorption cross section will reduce air quality compliance

    NASA Astrophysics Data System (ADS)

    Sofen, E. D.; Evans, M. J.; Lewis, A. C.

    2015-07-01

    Photometric ozone measurements rely upon an accurate value of the ozone absorption cross section at 253.65 nm. This has recently been reevaluated by Viallon et al. (2015) as 1.8 % smaller than the accepted value (Hearn, 1961) used for the preceding fifty years. Thus, ozone measurements that applied the older cross section systematically underestimate the amount of ozone in air. We correct the reported historical surface data from North America and Europe and find that this modest change in cross section has a significant impact on the number of locations that are out of compliance with air quality regulations if the air quality standards remain the same. We find 18, 23, and 20 % increases in the number of sites that are out of compliance with current US, Canadian, and European ozone air quality health standards for the year 2012. Should the new cross section value be applied, it would impact attainment of air quality standards and compliance with relevant clean air acts, unless the air quality target values themselves were also changed proportionately. We draw attention to how a small change in gas metrology has a global impact on attainment and compliance with legal air quality standards. We suggest that further laboratory work to evaluate the new cross section is needed and suggest three possible technical and policy responses should the new cross section be adopted.

  13. Krypton charge exchange cross sections for Hall effect thruster models

    SciTech Connect

    Hause, Michael L.; Prince, Benjamin D.; Bemish, Raymond J.

    2013-04-28

    Following discharge from a Hall effect thruster, charge exchange occurs between ions and un-ionized propellant atoms. The low-energy cations produced can disturb operation of onboard instrumentation or the thruster itself. Charge-exchange cross sections for both singly and doubly charged propellant atoms are required to model these interactions. While xenon is the most common propellant currently used in Hall effect thrusters, other propellants are being considered, in particular, krypton. We present here guided-ion beam measurements and comparisons to semiclassical calculations for Kr{sup +} + Kr and Kr{sup 2+} + Kr cross sections. The measurements of symmetric Kr{sup +} + Kr charge exchange are in good agreement with both the calculations including spin-orbit effects and previous measurements. For the symmetric Kr{sup 2+} + Kr reaction, we present cross section measurements for center-of-mass energies between 1 eV and 300 eV, which spans energies not previously examined experimentally. These cross section measurements compare well with a simple one-electron transfer model. Finally, cross sections for the asymmetric Kr{sup 2+} + Kr {yields} Kr{sup +} + Kr{sup +} reaction show an onset near 12 eV, reaching cross sections near constant value of 1.6 A{sup 2} with an exception near 70-80 eV.

  14. Topological Optimization of Beam Cross Section by Employing Extrusion Constraint

    NASA Astrophysics Data System (ADS)

    Zuberi, Rehan H.; Zhengxing, Zuo; Kai, Long

    2010-05-01

    Optimal cross-section design of beams plays a characteristic role which signifies the rigidity of the member in bending, shear and torsion load conditions. Practically modern overhead crane girders, railway bridge girders or rail tracks etc. require constant cross-section along the axial direction. Conventional topological optimization modeling procedures in such cases prove inadequate for the reason that these procedures generate non-uniform topologies along the axis of the bending member. To examine optimal topology of those structural bending members which commonly possess constant cross-section along the axis the topology optimization with extrusion constraint is more appropriate. The extrusion constraint method suggests a fresh approach to investigate optimal topologies of beam cross-section under the influence of realistic loading condition across the section at the beginning of design cycle. Presented study is focused upon the influence of various configuration and location of the load and boundary conditions on the topology of the of the beam cross-section which was not possible prior to the materialization of the extrusion or stamping constraint method. Several realistic loads and boundary conditions have been applied on the 3D beam model and optimal cross-section topologies obtained have uniform compliance history and convergent solutions. The lowest compliance criteria have been suggested to choose topologies as furthers shape and size optimization candidates during beam design process.

  15. Thermoelastic damping in microrings with circular cross-section

    NASA Astrophysics Data System (ADS)

    Li, Pu; Fang, Yuming; Zhang, Jianrun

    2016-01-01

    Predicting thermoelastic damping (TED) is crucial in the design of high Q micro-resonators. Microrings are often critical components in many micro-resonators. Some analytical models for TED in microrings have already been developed in the past. However, the previous works are limited to the microrings with rectangular cross-section. The temperature field in the rectangular cross-section is one-dimensional. This paper deals with TED in the microrings with circular cross-section. The temperature field in the circular cross-section is two-dimensional. This paper first presents a 2-D analytical model for TED in the microrings with circular cross-section. Only the two-dimensional heat conduction in the circular cross-section is considered. The heat conduction along the circumferential direction of the microring is neglected in the 2-D model. Then the 2-D model has been extended to cover the circumferential heat conduction, and a 3-D analytical model for TED has been developed. The analytical results from the present 2-D and 3-D models show good agreement with the numerical results of FEM model. The limitations of the present 2-D analytical model are assessed.

  16. General Constraints on Cross Sections Deduced from Surrogate Reactions

    SciTech Connect

    Younes, W

    2003-08-14

    Cross sections that cannot be measured in the laboratory, e.g. because the target lifetime is too short, can be inferred indirectly from a different reaction forming the same compound system, but with a more accessible beam/target combination (the ''surrogate-reaction'' technique). The reactions share the same compound system and a common decay mechanism, but they involve different formation processes. Therefore, an implicit constraint is imposed on the inferred cross section deduced from the measured surrogate-reaction data, through the common decay mechanism. In this paper, the mathematical consequences of this implicit constraint are investigated. General formulas are derived from upper and lower bounds on the inferred cross section, estimated from surrogate data in a procedure which does not require any modeling of the common decay process. As an example, the formulas developed here are applied to the case of the {sup 235}U(n,f) cross section, deduced from {sup 234}U(t,pf) surrogate data. The calculated bounds are not very tight in this particular case. However, by introducing a few qualitative assumptions about the physics of the fission process, meaningful bounds on the deduced cross section are obtained. Upper and lower limits for the cross-section ratio of the (n,f) reaction on the {sup 235}U isomer at E{sub x} = 77 eV relative to the (n,f) reaction on the ground state are also calculated. The generalization of this technique to other surrogate reactions is discussed.

  17. A genetic algorithm to reduce stream channel cross section data

    USGS Publications Warehouse

    Berenbrock, C.

    2006-01-01

    A genetic algorithm (GA) was used to reduce cross section data for a hypothetical example consisting of 41 data points and for 10 cross sections on the Kootenai River. The number of data points for the Kootenai River cross sections ranged from about 500 to more than 2,500. The GA was applied to reduce the number of data points to a manageable dataset because most models and other software require fewer than 100 data points for management, manipulation, and analysis. Results indicated that the program successfully reduced the data. Fitness values from the genetic algorithm were lower (better) than those in a previous study that used standard procedures of reducing the cross section data. On average, fitnesses were 29 percent lower, and several were about 50 percent lower. Results also showed that cross sections produced by the genetic algorithm were representative of the original section and that near-optimal results could be obtained in a single run, even for large problems. Other data also can be reduced in a method similar to that for cross section data.

  18. The effect of mandibular setback or two-jaws surgery on pharyngeal airway among different genders.

    PubMed

    Degerliyurt, K; Ueki, K; Hashiba, Y; Marukawa, K; Simsek, B; Okabe, K; Nakagawa, K; Yamamoto, E

    2009-06-01

    Cephalometric studies show significant gender differences in the size of the pharyngeal airway space. This study aimed to investigate and compare morphologic changes after mandibular setback or two-jaws surgery on the pharyngeal airway in men and women using computed tomography (CT). The sample included 34 women and 13 men diagnosed with Class III skeletal deformities, who had been treated by mandibular setback or bimaxillary surgery (maxillary advancement and mandibular setback). Anteroposterior, lateral and cross-sectional area dimensions of the airway, at the level of soft palate and base of tongue, were measured pre- and postoperatively on CT images. In the mandibular setback group, the anteroposterior and cross-sectional area of the pharyngeal airway at the level of the soft palate and base of tongue were significantly reduced for men or women (P<.05). In the two-jaws surgery group, only midsagittal anteroposterior dimensions at the same levels were significantly decreased for men or women (P<.05). The difference between any values measured between men and women who received bilateral sagittal split ramus osteotomy setback surgery or two-jaws surgery for the treatment of class III anteroposterior discrepancy were not statistically significant (P>.05). This study suggests that oropharyngeal airway measurements, important for airway patency, do not demonstrate sex dimorphism.

  19. Profile variation impact on FIB cross-section metrology

    NASA Astrophysics Data System (ADS)

    Cordes, Aaron; Bunday, Benjamin; Nadeau, Jim

    2012-03-01

    The focused ion beam (FIB) milling tool is an important component of reference metrology and process characterization, both as a supporting instrument for bulk sample preparation before forwarding to the transmission electron microscope (TEM) and other instruments and as an in situ measurement instrument using angled scanning electron microscopy. As features grow denser, deeper and more demanding, full-profile reference metrology is needed, and this methodology will only grow in importance. Thus, the ability to extract accurate dimensional and profile information out of the crosssectional faces produced by FIB milling is critical. For features that demonstrate perfect symmetry in the plane of the cross section, analyzing images and extracting metrology data are straightforward. However, for industrial materials, symmetry is not a safe assumption: as features shrink, the line edge and sidewall roughness increases as a percentage of the overall feature dimension. Furthermore, with the introduction of more complex architectures such as 3D memory and FinFETs, the areas of greatest interest, such as the intersections of wrap-around gates, cannot be assumed to be symmetrical in any given plane if cut placement is not precisely controlled. Therefore it is important to establish the exact location and repeatability of the cross-section plane, both in terms of coordinate placement and effective angle of the milled surface. To this end, we prepared designed-in line edge roughness samples in the Albany Nanotech facility using SEMATECH's AMAG6 metrology reticle. The samples were thoroughly characterized before being milled by a non-destructive, sidewall-scanning atomic force microscope (AFM). These samples are then milled and measured under varying process and setup parameters using a single-beam FIB with angled SEM. We established methodologies that allow precise alignment of the cut planes of slice-and-view FIB milling to 3D-AFM scan lines to compare repeated sections

  20. Cross sections for bare and dressed carbon ions in water and neon

    NASA Astrophysics Data System (ADS)

    Liamsuwan, Thiansin; Nikjoo, Hooshang

    2013-02-01

    other calculations at lower energies. The discrepancy arises from the inclusion of all carbon charge states and coupling between electron capture and target ionization channels, while other models use an average projectile charge. The CTMC model presented here provides a tool for cross section calculations for low and intermediate energy carbon projectiles. The calculated cross sections are required for Monte Carlo track structure simulations of full-slowing-down tracks of carbon ions. The work paves the way for biophysical studies and dosimetry at the cellular and subcellular levels in the Bragg peak area of a therapeutic carbon ion beam.

  1. Cross sections for bare and dressed carbon ions in water and neon.

    PubMed

    Liamsuwan, Thiansin; Nikjoo, Hooshang

    2013-02-01

    than the other calculations at lower energies. The discrepancy arises from the inclusion of all carbon charge states and coupling between electron capture and target ionization channels, while other models use an average projectile charge. The CTMC model presented here provides a tool for cross section calculations for low and intermediate energy carbon projectiles. The calculated cross sections are required for Monte Carlo track structure simulations of full-slowing-down tracks of carbon ions. The work paves the way for biophysical studies and dosimetry at the cellular and subcellular levels in the Bragg peak area of a therapeutic carbon ion beam.

  2. Unintended Pregnancy in Ethiopia: Community Based Cross-Sectional Study

    PubMed Central

    Berta Badi, Martha

    2016-01-01

    Introduction. Unintended pregnancy is defined as a pregnancy which is a sum of mistimed pregnancy (pregnancy wanted at a later time) and unwanted pregnancy (pregnancy which is not wanted at all). Unintended pregnancy is a global public health problem and its sequels are major causes for maternal and neonatal morbidity and mortality with its effect to maternal metal illness as well. Objective. To determine the prevalence and associated factors of unintended pregnancy in Debre Birhan town, northeast of Ethiopia, in 2014. Method. Community based cross-sectional study and questionnaire developed from Ethiopian demographic health survey 2011. Participants were 690 currently pregnant mothers. Association of unintended pregnancy with factors was measured with bivariate and multivariate logistic regressions. Result. In this study unintended pregnancy is found to be 23.5%. Being formerly married and never married, distance to the nearest health facility >80 minutes, gravidity >5, 1-2 parity, and partner disagreement on desired number of children are the variables significantly associated with unintended pregnancy. Conclusion. Significant proportion of unintended pregnancy is found in the study area. To minimize unintended pregnancy concerned bodies should work on the identified factors, so we can minimize maternal and neonatal morbidity and mortality and keep the health of the family specifically and country in general.

  3. Child abuse: Cross-sectional survey of general dentists

    PubMed Central

    Kaur, Harsimran; Chaudhary, Seema; Choudhary, Nidhi; Manuja, Naveen; Chaitra, T.R.; Amit, Sinha Ashish

    2015-01-01

    Background Child abuse continues to be a social menace causing both physical and emotional trauma to benevolent children. Census has shown that nearly 50–75% of child abuse include trauma to mouth, face, and head. Thus, dental professionals are in strategic position to identify physical and emotional manifestations of abuse. Aim A cross-sectional survey was undertaken to assess knowledge and attitude of dental practitioners regarding child abuse and to identify the barriers in reporting the same. Methods With prior consent, a 20-question survey including both multiple choice and dichotomous (Yes/No) questions was mailed to 120 state-registered general dentists, and the data collected were subjected to statistical analysis. Results Overall response rate to the questionnaires was 97%. Lack of knowledge about dentist's role in reporting child abuse accounted to 55% in the reasons for hesitancy to report. Pearson chi-square test did not show any significant difference between male and female regarding reason for hesitancy to report and legal obligation of dentists. Conclusion Although respondent dentists were aware of the diagnosis of child abuse, they were hesitant and unaware of the appropriate authority to report. Increased instruction in the areas of recognition and reporting of child abuse and neglect should be emphasized. PMID:27195209

  4. Unintended Pregnancy in Ethiopia: Community Based Cross-Sectional Study

    PubMed Central

    Berta Badi, Martha

    2016-01-01

    Introduction. Unintended pregnancy is defined as a pregnancy which is a sum of mistimed pregnancy (pregnancy wanted at a later time) and unwanted pregnancy (pregnancy which is not wanted at all). Unintended pregnancy is a global public health problem and its sequels are major causes for maternal and neonatal morbidity and mortality with its effect to maternal metal illness as well. Objective. To determine the prevalence and associated factors of unintended pregnancy in Debre Birhan town, northeast of Ethiopia, in 2014. Method. Community based cross-sectional study and questionnaire developed from Ethiopian demographic health survey 2011. Participants were 690 currently pregnant mothers. Association of unintended pregnancy with factors was measured with bivariate and multivariate logistic regressions. Result. In this study unintended pregnancy is found to be 23.5%. Being formerly married and never married, distance to the nearest health facility >80 minutes, gravidity >5, 1-2 parity, and partner disagreement on desired number of children are the variables significantly associated with unintended pregnancy. Conclusion. Significant proportion of unintended pregnancy is found in the study area. To minimize unintended pregnancy concerned bodies should work on the identified factors, so we can minimize maternal and neonatal morbidity and mortality and keep the health of the family specifically and country in general. PMID:27656213

  5. Unintended Pregnancy in Ethiopia: Community Based Cross-Sectional Study.

    PubMed

    Getu Melese, Kidest; Gebrie, Mignote Hailu; Berta Badi, Martha; Fekadu Mersha, Wubalem

    2016-01-01

    Introduction. Unintended pregnancy is defined as a pregnancy which is a sum of mistimed pregnancy (pregnancy wanted at a later time) and unwanted pregnancy (pregnancy which is not wanted at all). Unintended pregnancy is a global public health problem and its sequels are major causes for maternal and neonatal morbidity and mortality with its effect to maternal metal illness as well. Objective. To determine the prevalence and associated factors of unintended pregnancy in Debre Birhan town, northeast of Ethiopia, in 2014. Method. Community based cross-sectional study and questionnaire developed from Ethiopian demographic health survey 2011. Participants were 690 currently pregnant mothers. Association of unintended pregnancy with factors was measured with bivariate and multivariate logistic regressions. Result. In this study unintended pregnancy is found to be 23.5%. Being formerly married and never married, distance to the nearest health facility >80 minutes, gravidity >5, 1-2 parity, and partner disagreement on desired number of children are the variables significantly associated with unintended pregnancy. Conclusion. Significant proportion of unintended pregnancy is found in the study area. To minimize unintended pregnancy concerned bodies should work on the identified factors, so we can minimize maternal and neonatal morbidity and mortality and keep the health of the family specifically and country in general. PMID:27656213

  6. Ultra wide band 3-D cross section (RCS) holography

    SciTech Connect

    Collins, H.D.; Hall, T.E.

    1992-07-01

    Ultra wide band impulse holography is an exciting new concept for predictive radar cross section (RCS) evaluation employing near-field measurements. Reconstruction of the near-field hologram data maps the target`s scattering areas, and uniquely identifies the ``hot spot`` locations on the target. In addition, the target and calibration sphere`s plane wave angular spectrums are computed (via digital algorithm) and used to generate the target`s far-field RCS values in three dimensions for each frequency component in the impulse. Thin and thick targets are defined in terms of their near-field amplitude variations in range. Range gating and computer holographic techniques are applied to correct these variations. Preliminary experimental results on various targets verify the concept of RCS holography. The unique 3-D presentation (i.e., typically containing 524,288 RCS values for a 1024 {times} 512 sampled aperture for every frequency component) illustrates the efficacy of target recognition in terms of its far-field plane wave angular spectrum image. RCS images can then be viewed at different angles for target recognition, etc.

  7. Ultra wide band 3-D cross section (RCS) holography

    SciTech Connect

    Collins, H.D.; Hall, T.E.

    1992-07-01

    Ultra wide band impulse holography is an exciting new concept for predictive radar cross section (RCS) evaluation employing near-field measurements. Reconstruction of the near-field hologram data maps the target's scattering areas, and uniquely identifies the hot spot'' locations on the target. In addition, the target and calibration sphere's plane wave angular spectrums are computed (via digital algorithm) and used to generate the target's far-field RCS values in three dimensions for each frequency component in the impulse. Thin and thick targets are defined in terms of their near-field amplitude variations in range. Range gating and computer holographic techniques are applied to correct these variations. Preliminary experimental results on various targets verify the concept of RCS holography. The unique 3-D presentation (i.e., typically containing 524,288 RCS values for a 1024 {times} 512 sampled aperture for every frequency component) illustrates the efficacy of target recognition in terms of its far-field plane wave angular spectrum image. RCS images can then be viewed at different angles for target recognition, etc.

  8. A Multigroup Reaction Cross-Section Collapsing Code and Library of 154-Group Fission-Product Cross Sections.

    1983-03-23

    Version 01/02 The code reads multigroup cross sections from a compatible data file and collapses user-selected reaction cross sections to any few-group structure using one of a variety of user neutron flux spectrum options given below: Option Flux description 1 Built-in function including Maxwellian, fission, fusion and slowing-down regions and requiring user-specified parameters and energy-region boundaries. 2 Set of log-log flux-energy interpolation points read from input cross-section data file. 3 Set of log-log flux-energy interpolationmore » points read from user-supplied card input. 4 - 6 Histogram flux values read from user-supplied card input in arbitrary group structure in units of flux-per unit-energy, flux-per-unit lethargy, or integral group flux. LAFPX-E may be used to collapse any set of multigroup reaction cross sections furnished in the required format. However, the code was developed for, and is furnished with, a library of 154-group fission-product cross sections processed from ENDF/B-IV with a typical light water reactor (LWR) flux spectrum and temperature. Four-group radiative capture cross sections produced for LWR calculations are tabulated in the code documentation and are incorporated in the EPRI-CINDER data library, RSIC Code Package CCC-309.« less

  9. The impact of television viewing on brain structures: cross-sectional and longitudinal analyses.

    PubMed

    Takeuchi, Hikaru; Taki, Yasuyuki; Hashizume, Hiroshi; Asano, Kohei; Asano, Michiko; Sassa, Yuko; Yokota, Susumu; Kotozaki, Yuka; Nouchi, Rui; Kawashima, Ryuta

    2015-05-01

    Television (TV) viewing is known to affect children's verbal abilities and other physical, cognitive, and emotional development in psychological studies. However, the brain structural development associated with TV viewing has never been investigated. Here we examined cross-sectional correlations between the duration of TV viewing and regional gray/white matter volume (rGMV/rWMV) among 133 boys and 143 girls as well as correlations between the duration of TV viewing and longitudinal changes that occurred a few years later among 111 boys and 105 girls. After correcting for confounding factors, we found positive effects of TV viewing on rGMV of the frontopolar and medial prefrontal areas in cross-sectional and longitudinal analyses, positive effects of TV viewing on rGMV/rWMV of areas of the visual cortex in cross-sectional analyses, and positive effects of TV viewing on rGMV of the hypothalamus/septum and sensorimotor areas in longitudinal analyses. We also confirmed negative effects of TV viewing on verbal intelligence quotient (IQ) in cross-sectional and longitudinal analyses. These anatomical correlates may be linked to previously known effects of TV viewing on verbal competence, aggression, and physical activity. In particular, the present results showed effects of TV viewing on the frontopolar area of the brain, which has been associated with intellectual abilities.

  10. The impact of television viewing on brain structures: cross-sectional and longitudinal analyses.

    PubMed

    Takeuchi, Hikaru; Taki, Yasuyuki; Hashizume, Hiroshi; Asano, Kohei; Asano, Michiko; Sassa, Yuko; Yokota, Susumu; Kotozaki, Yuka; Nouchi, Rui; Kawashima, Ryuta

    2015-05-01

    Television (TV) viewing is known to affect children's verbal abilities and other physical, cognitive, and emotional development in psychological studies. However, the brain structural development associated with TV viewing has never been investigated. Here we examined cross-sectional correlations between the duration of TV viewing and regional gray/white matter volume (rGMV/rWMV) among 133 boys and 143 girls as well as correlations between the duration of TV viewing and longitudinal changes that occurred a few years later among 111 boys and 105 girls. After correcting for confounding factors, we found positive effects of TV viewing on rGMV of the frontopolar and medial prefrontal areas in cross-sectional and longitudinal analyses, positive effects of TV viewing on rGMV/rWMV of areas of the visual cortex in cross-sectional analyses, and positive effects of TV viewing on rGMV of the hypothalamus/septum and sensorimotor areas in longitudinal analyses. We also confirmed negative effects of TV viewing on verbal intelligence quotient (IQ) in cross-sectional and longitudinal analyses. These anatomical correlates may be linked to previously known effects of TV viewing on verbal competence, aggression, and physical activity. In particular, the present results showed effects of TV viewing on the frontopolar area of the brain, which has been associated with intellectual abilities. PMID:24256892

  11. ACTIV87: Fast Neutron Activation Cross Section File

    1993-08-01

    4. HISTORICAL BACKGROUND AND INFORMATION ACTIV87 is a compilation of fast neutron induced activation reaction cross-sections. The compilation covers energies from threshold to 20 MeV and is based on evaluated data taken from other evaluated data libraries and individual evaluations. The majority of these evaluations were performed by using available experimental data. The aforementioned available experimental data were used in the selection of needed parameters for theoretical computations and for normalizing the results of suchmore » computations. Theoretical calculations were also used for interpolation and extrapolation of experimental cross-section data. All of the evaluated data curves were compared with experimental data that had been reported over the four year period preceding 1987. Only those cross-sections not in contradiction with experimental data that was current in 1987 were retained in the activation file, ACTIV87. In cases of several conflicting evaluations, that evaluation was chosen which best corresponded to the experimental data. A few evaluated curves were renormalized in accordance with the results of the latest precision measurements. 5. APPLICATION OF THE DATA 6. SOURCE AND SCOPE OF DATA The following libraries and individual files of evaluated neutron cross-section data were used for the selection of the activation cross-sections: the BOSPOR Library, the Activation File of the Evaluated Nuclear Data Library, the Evaluated Neutron Data File (ENDF/B-V) Activation File, the International Reactor Dosimetry File (IRDF-82), and individual evaluations carried out under various IAEA research contracts. The file of selected reactions contains 206 evaluated cross-section curves of the (n,2n), (n,p) and (n,a) reactions which lead to radioactive products and may be used in many practical applications of neutron activation analysis. Some competing activation reactions, usually with low cross-section values, are given for completeness.« less

  12. Measurement of the 242Pu neutron capture cross section

    NASA Astrophysics Data System (ADS)

    Buckner, M. Q.; Wu, C. Y.; Henderson, R. A.; Bucher, B.; Bredeweg, T. A.; Baramsai, B.; Couture, A.; Jandel, M.; Mosby, S.; O'Donnell, J. M.; Ullmann, J. L.; Chyzh, A.; Dance Collaboration

    2015-10-01

    Precision (n,f) and (n, γ) cross sections are important for the network calculations of the radiochemical diagnostic chain for the U.S. DOE's Stockpile Stewardship Program. 242Pu(n, γ) cross section is relevant to the network calculations of Pu and Am. Additionally, new reactor concepts have catalyzed considerable interest in the measurement of improved cross sections for neutron-induced reactions on key actinides. To date, little or no experimental data has been reported on 242Pu(n, γ) for incident neutron energy below 50 keV. A new measurement of the 242Pu(n, γ) reaction was performed with the DANCE together with an improved PPAC for fission-fragment detection at LANSCE during FY14. The relative scale of the 242Pu(n, γ) cross section spans four orders of magnitude for incident neutron energies from thermal to ~ 30 keV. The absolute scale of the 242Pu(n, γ) cross section is set according to the measured 239Pu(n,f) resonance at 7.8 eV; the target was spiked with 239Pu for this measurement. The absolute 242Pu(n, γ) neutron capture cross section is ~ 30% higher than the cross section reported in ENDF for the 2.7 eV resonance. Latest results to be reported. Funded by U.S. DOE Contract No. DE-AC52-07NA27344 (LLNL) and DE-AC52-06NA25396 (LANL). U.S. DOE/NNSA Office of Defense Nuclear Nonproliferation Research and Development. Isotopes (ORNL).

  13. Electron Impact Ionization Cross Sections in Rb and Cs.

    NASA Astrophysics Data System (ADS)

    Reddish, T. J.; Lukomski, M.; Sutton, S.; Kedzierski, W.; McConkey, J. W.; Bartschat, K.; Bartlett, P. L.; Stelbovics, A. T.; Bray, I.

    2006-05-01

    We present a new atom trapping technique for determining absolute, total ionisation cross sections (TICS) out of an excited atom. The novel feature of this method is in utilizing Doppler cooling of neutral atoms to determine ionisation cross sections. This fluorescence-monitoring experiment, which is a variant of the `trap loss' technique, has enabled us to obtain the experimental electron impact ionisation cross sections out of the Cs 6^2P3/2 excited state between 7 - 400 eV. New CCC, R-Matrix with Pseudo-States (RMPS), and Born approximation single ionisation cross sections (SICS) are also presented for both the ground and excited states of Cs and Rb, and compared with the available experimental data. The comparison of the results reveals the importance of the autoionisation and multiple ionisation contributions to the TICS. The autoionisation contribution appears to be substantial for ionisation out of the Cs 6^2P and Rb 5^2P excited states; ˜ 3-4 larger than the direct ionisation contribution predicted by CCC at ˜ 30-50 eV. This surprising result shows the importance of multi-electron processes in determining the ionisation cross sections of heavy alkali atoms.

  14. Simulation of multistatic and backscattering cross sections for airborne radar

    NASA Astrophysics Data System (ADS)

    Biggs, Albert W.

    1986-07-01

    In order to determine susceptibilities of airborne radar to electronic countermeasures and electronic counter-countermeasures simulations of multistatic and backscattering cross sections were developed as digital modules in the form of algorithms. Cross section algorithms are described for prolate (cigar shape) and oblate (disk shape) spheroids. Backscattering cross section algorithms are also described for different categories of terrain. Backscattering cross section computer programs were written for terrain categorized as vegetation, sea ice, glacial ice, geological (rocks, sand, hills, etc.), oceans, man-made structures, and water bodies. PROGRAM SIGTERRA is a file for backscattering cross section modules of terrain (TERRA) such as vegetation (AGCROP), oceans (OCEAN), Arctic sea ice (SEAICE), glacial snow (GLASNO), geological structures (GEOL), man-made structures (MAMMAD), or water bodies (WATER). AGCROP describes agricultural crops, trees or forests, prairies or grassland, and shrubs or bush cover. OCEAN has the SLAR or SAR looking downwind, upwind, and crosswind at the ocean surface. SEAICE looks at winter ice and old or polar ice. GLASNO is divided into a glacial ice and snow or snowfields. MANMAD includes buildings, houses, roads, railroad tracks, airfields and hangars, telephone and power lines, barges, trucks, trains, and automobiles. WATER has lakes, rivers, canals, and swamps. PROGRAM SIGAIR is a similar file for airborne targets such as prolate and oblate spheroids.

  15. Cross Sections and Transport Properties of BR- Ions in AR

    NASA Astrophysics Data System (ADS)

    Jovanovic, Jasmina; Stojanovic, Vladimir; Raspopovic, Zoran; Petrovic, Zoran

    2014-10-01

    We have used a combination of a simple semi-analytic theory - Momentum Transfer Theory (MTT) and exact Monte Carlo (MC) simulations to develop Br- in Ar momentum transfer cross section based on the available data for reduced mobility at the temperature T = 300 K over the range 10 Td <= E / N <= 300 Td. At very low energies, we have extrapolated obtained cross sections towards Langevin's cross section. Also, we have extrapolated data to somewhat higher energies based on behavior of similar ions in similar gases and by the addition of the total detachment cross section that was used from the threshold around 7.7 eV. Relatively complete set was derived which can be used in modeling of plasmas by both hybrid, particle in cell (PIC) and fluid codes. A good agreement between calculated and measured ion mobilities and longitudinal diffusion coefficients is an independent proof of the validity of the cross sections that were derived for the negative ion mobility data. In addition to transport coefficients we have also calculated the net rate coefficients of elastic scattering and detachment. Author acknowledge Ministry of Education, Science and Technology, Proj. Nos. 171037 and 410011.

  16. Electromagnetic Dissociation Cross Sections using Weisskopf-Ewing Theory

    NASA Technical Reports Server (NTRS)

    Adamczyk, Anne M.; Norbury, John W.

    2011-01-01

    It is important that accurate estimates of crew exposure to radiation are obtained for future long-term space missions. Presently, several space radiation transport codes exist to predict the radiation environment, all of which take as input particle interaction cross sections that describe the nuclear interactions between the particles and the shielding material. The space radiation transport code HZETRN uses the nuclear fragmentation model NUCFRG2 to calculate Electromagnetic Dissociation (EMD) cross sections. Currently, NUCFRG2 employs energy independent branching ratios to calculate these cross sections. Using Weisskopf-Ewing (WE) theory to calculate branching ratios, however, is more advantageous than the method currently employed in NUCFRG2. The WE theory can calculate not only neutron and proton emission, as in the energy independent branching ratio formalism used in NUCFRG2, but also deuteron, triton, helion, and alpha particle emission. These particles can contribute significantly to total exposure estimates. In this work, photonuclear cross sections are calculated using WE theory and the energy independent branching ratios used in NUCFRG2 and then compared to experimental data. It is found that the WE theory gives comparable, but mainly better agreement with data than the energy independent branching ratio. Furthermore, EMD cross sections for single neutron, proton, and alpha particle removal are calculated using WE theory and an energy independent branching ratio used in NUCFRG2 and compared to experimental data.

  17. Cross-section fluctuations in chaotic scattering systems

    NASA Astrophysics Data System (ADS)

    Ericson, Torleif E. O.; Dietz, Barbara; Richter, Achim

    2016-10-01

    Exact analytical expressions for the cross-section correlation functions of chaotic scattering systems have hitherto been derived only under special conditions. The objective of the present article is to provide expressions that are applicable beyond these restrictions. The derivation is based on a statistical model of Breit-Wigner type for chaotic scattering amplitudes which has been shown to describe the exact analytical results for the scattering (S )-matrix correlation functions accurately. Our results are given in the energy and in the time representations and apply in the whole range from isolated to overlapping resonances. The S -matrix contributions to the cross-section correlations are obtained in terms of explicit irreducible and reducible correlation functions. Consequently, the model can be used for a detailed exploration of the key features of the cross-section correlations and the underlying physical mechanisms. In the region of isolated resonances, the cross-section correlations contain a dominant contribution from the self-correlation term. For narrow states the self-correlations originate predominantly from widely spaced states with exceptionally large partial width. In the asymptotic region of well-overlapping resonances, the cross-section autocorrelation functions are given in terms of the S -matrix autocorrelation functions. For inelastic correlations, in particular, the Ericson fluctuations rapidly dominate in that region. Agreement with known analytical and experimental results is excellent.

  18. Electron-impact ionization cross section of rubidium

    NASA Astrophysics Data System (ADS)

    Kim, Yong-Ki; Migdałek, Jacek; Siegel, Wojciech; Bieroń, Jacek

    1998-01-01

    A theoretical model for electron-impact ionization cross section has been applied to Rb and the theoretical cross section (from the threshold to 1 keV in incident energy) is in good agreement with the recent experimental data obtained using Rb atoms trapped in a magneto-optical trap. The theoretical model, called the binary-encounter-dipole (BED) model, combines a modified Mott cross section with the high-energy behavior of Born cross sections. To obtain the continuum dipole oscillator strength df/dE of the 5s electron required in the BED model, we used Dirac-Fock continuum wave functions with a core polarization potential that reproduced the known position of the Cooper minimum in the photoionization cross section. For inner-shell ionization, we used a simpler version of df/dE, which retained the hydrogenic shape. The contributions of the 4p-->4d, 5s, and 5p autoionizing excitations were estimated using the plane-wave Born approximation. As a by-product, we also present the dipole oscillator strengths for the 5s-->np1/2 and 5s-->np3/2 transitions for high principal quantum numbers n near the ionization threshold obtained from the Dirac-Fock wave functions with the same core polarization potential as that used for the continuum wave functions.

  19. Optimization of multi-group cross sections for fast reactor analysis

    SciTech Connect

    Chin, M. R.; Manalo, K. L.; Edgar, C. A.; Paul, J. N.; Molinar, M. P.; Redd, E. M.; Yi, C.; Sjoden, G. E.

    2013-07-01

    The selection of the number of broad energy groups, collapsed broad energy group boundaries, and their associated evaluation into collapsed macroscopic cross sections from a general 238-group ENDF/B-VII library dramatically impacted the k eigenvalue for fast reactor analysis. An analysis was undertaken to assess the minimum number of energy groups that would preserve problem physics; this involved studies using the 3D deterministic transport parallel code PENTRAN, the 2D deterministic transport code SCALE6.1, the Monte Carlo based MCNP5 code, and the YGROUP cross section collapsing tool on a spatially discretized MOX fuel pin comprised of 21% PUO{sub 2}-UO{sub 2} with sodium coolant. The various cases resulted in a few hundred pcm difference between cross section libraries that included the 238 multi-group reference, and cross sections rendered using various reaction and adjoint weighted cross sections rendered by the YGROUP tool, and a reference continuous energy MCNP case. Particular emphasis was placed on the higher energies characteristic of fission neutrons in a fast spectrum; adjoint computations were performed to determine the average per-group adjoint fission importance for the MOX fuel pin. This study concluded that at least 10 energy groups for neutron transport calculations are required to accurately predict the eigenvalue for a fast reactor system to within 250 pcm of the 238 group case. In addition, the cross section collapsing/weighting schemes within YGROUP that provided a collapsed library rendering eigenvalues closest to the reference were the contribution collapsed, reaction rate weighted scheme. A brief analysis on homogenization of the MOX fuel pin is also provided, although more work is in progress in this area. (authors)

  20. Assessment of methacholine-induced airway constriction by ultrafast high-resolution computed tomography.

    PubMed

    Amirav, I; Kramer, S S; Grunstein, M M; Hoffman, E A

    1993-11-01

    Assessment of changes in airway dimensions during bronchoconstriction is conventionally based on measurements of respiratory mechanics. We evaluated the efficacy of ultrafast high-resolution computed tomography (UHRCT) to directly determine the dynamic changes in cross-sectional area (CSA) of airways in response to methacholine (MCh). UHRCT scans were obtained at functional residual capacity before (baseline) and after intravenous bolus injections of MCh (10(-8.5)-10(-7.0) mol/kg) to seven mechanically ventilated pigs. Changes in CSA of bronchi of varying baseline size (1-10 mm diam) were determined by using a customized image processing software package (VIDA) based on a user-directed computer-adjusted edge-finding algorithm. MCh induced dose-dependent decreases in CSA, which were paralleled by increases in airway opening pressure at higher doses of MCh; at lower doses of MCh, decreases in CSA of smaller airways were detected without concomitant changes in airway opening pressure. Changes in CSA were heterogeneous and variable, especially in the smaller airway ranges. The results of the present study support the concept that UHRCT can be used in conjunction with bolus challenges to effectively determine dose-response changes in airway caliber in both large and small airways. This technique provides data that may not be reflected by conventional lung function measurements and, hence, is a useful tool to study airway reactivity.

  1. Particle Deposition in Human Lungs due to Varying Cross-Sectional Ellipticity of Left and Right Main Bronchi

    NASA Astrophysics Data System (ADS)

    Roth, Steven; Oakes, Jessica; Shadden, Shawn

    2015-11-01

    Particle deposition in the human lungs can occur with every breathe. Airbourne particles can range from toxic constituents (e.g. tobacco smoke and air pollution) to aerosolized particles designed for drug treatment (e.g. insulin to treat diabetes). The effect of various realistic airway geometries on complex flow structures, and thus particle deposition sites, has yet to be extensively investigated using computational fluid dynamics (CFD). In this work, we created an image-based geometric airway model of the human lung and performed CFD simulations by employing multi-domain methods. Following the flow simulations, Lagrangian particle tracking was used to study the effect of cross-sectional shape on deposition sites in the conducting airways. From a single human lung model, the cross-sectional ellipticity (the ratio of major and minor diameters) of the left and right main bronchi was varied systematically from 2:1 to 1:1. The influence of the airway ellipticity on the surrounding flow field and particle deposition was determined.

  2. A New Scaling Law of Resonance in Total Scattering Cross Section in Gases

    NASA Astrophysics Data System (ADS)

    Raju, Gorur Govinda

    2009-10-01

    Electrical discharges in gases continue to be an active area of research because of industrial applications such as power systems, environmental clean up, laser technology, semiconductor fabrication etc. A fundamental knowledge of electron-gas neutral interaction is indispensable and, the total scattering cross section is one of the quantities that have been measured extensively. The energy dependence of the total cross sections shows peaks or resonance processes that are operative in the collision process. These peaks and the energies at which they occur are shown to satisfy a broad relationship involving the polarizability and the dipole moment of the target particle. Data on 62 target particles belonging to the following species are analyzed. (Eq 1) Rare gas atoms (Eq 2) Di-atomic molecules with combinations of polar, non-polar, attaching, and non-attaching properties Poly-atomic molecules with combinations of polar, non-polar, attaching, and non-attaching properties. Methods of improving the newly identified scaling law and possible application have been identified. 1 INTRODUCTION: Data on electron-neutral interactions are one of the most fundamental in the study of gaseous electronics and an immense literature, both experimental and theoretical, has become available since about the year 1920. [1-5]. In view of the central role which these data play in all facets of gas discharges and plasma science, it is felt that a critical review of available data is timely, mainly for the community of high voltage engineers and industries connected with plasma science in general. The electron-neutral interaction, often referred to as scattering in the scientific literature, is quantified by using the quantity called the total scattering cross section (QT, m^2). In the literature on cross section, total cross section and total scattering cross section are terms used synonymously and we follow the same practice. A definition may be found in reference [1]. This paper concerns

  3. Inversion of rotationally inelastic differential cross sections under sudden conditions

    NASA Astrophysics Data System (ADS)

    Schinke, Reinhard

    1980-12-01

    An inversion method for rotationally inelastic atom-diatom differential cross sections based on the infinite-order-sudden (IOS) approximation is presented. It consists of two separate steps: (1) The scattering phase shift, which is a function of the partial wave parameter l and the orientation angle γ, is determined by least-squares fitting of the reference cross sections. (2) For fixed orientation γ the R dependence of the interaction potential in obtained from the l dependence of the phase shift using the Firsov technique. This method is applicable in the so-called strong coupling case when rotational rainbow features are dominant and yields information about the anisotropy of the potential surface in the repulsive region. Because of the centrifugal sudden condition, scattering systems with deep potential wells cannot be treated by the present method. Test calculations are performed using theoretical IOS cross sections obtained from a realistic He-Na2 surface as reference data.

  4. pi+- p differential cross sections at low energies

    SciTech Connect

    H. Denz; P. Amaudruz; J.T. Brack; J. Breitschopf; P. Camerini; J.L. Clark; H. Clement; L. Felawka; E. Fragiacomo; E.F. Gibson; N. Grion; G.J. Hofman; B. Jamieson; E.L. Mathie; R. Meier; G. Moloney; D. Ottewell; O. Patarakin; J.D. Patterson; M.M. Pavan; S. Piano; K. Raywood; R.A. Ristinen; R. Rui; M.E. Sevior; G.R. Smith; J. Stahov; R. Tacik; G.J. Wagner; F. von Wrochem; D.M. Yeomans

    2005-12-03

    Differential cross sections for pi- p and pi+ p elastic scattering were measured at five energies between 19.9 and 43.3 MeV. The use of the CHAOS magnetic spectrometer at TRIUMF, supplemented by a range telescope for muon background suppression, provided simultaneous coverage of a large part of the full angular range, thus allowing very precise relative cross section measurements. The absolute normalization was determined with a typical accuracy of 5 %. This was verified in a simultaneous measurement of muon proton elastic scattering. The measured cross sections show some deviations from phase shift analysis predictions, in particular at large angles and low energies. From the new data we determine the real part of the isospin forward scattering amplitude.

  5. 63Ni (n ,γ ) cross sections measured with DANCE

    NASA Astrophysics Data System (ADS)

    Weigand, M.; Bredeweg, T. A.; Couture, A.; Göbel, K.; Heftrich, T.; Jandel, M.; Käppeler, F.; Lederer, C.; Kivel, N.; Korschinek, G.; Krtička, M.; O'Donnell, J. M.; Ostermöller, J.; Plag, R.; Reifarth, R.; Schumann, D.; Ullmann, J. L.; Wallner, A.

    2015-10-01

    The neutron capture cross section of the s -process branch nucleus 63Ni affects the abundances of other nuclei in its region, especially 63Cu and 64Zn. In order to determine the energy-dependent neutron capture cross section in the astrophysical energy region, an experiment at the Los Alamos National Laboratory has been performed using the calorimetric 4 π BaF2 array DANCE. The (n ,γ ) cross section of 63Ni has been determined relative to the well-known 197Au standard with uncertainties below 15%. Various 63Ni resonances have been identified based on the Q value. Furthermore, the s -process sensitivity of the new values was analyzed with the new network calculation tool NETZ.

  6. Photoabsorption cross section of acetylene in the EUV region

    NASA Technical Reports Server (NTRS)

    Wu, C. Y. R.; Judge, D. L.

    1985-01-01

    The measurement of the absolute photoabsorption cross sections of C2H2 in the 175-740 A region by means of a double ionization chamber is reported. The continuum background source is the synchrotron radiation emitted by the Wisconsin 240 MeV electron storage ring. It is found that the cross sections range from 2 to a maximum of 36 Mb. Two new Rydberg series are identified and the cross section data are applied in the analysis of various sum rules. From the rules, it is shown that the data of C2H2 in the 580-1088 A range may be too low, while the measured ionization transition moment may be too high.

  7. High Energy Measurement of the Deuteron Photodisintegration Differential Cross Section

    SciTech Connect

    Elaine Schulte

    2002-05-01

    New measurements of the high energy deuteron photodisintegration differential cross section were made at the Thomas Jefferson National Accelerator Facility in Newport News, Virginia. Two experiments were performed. Experiment E96-003 was performed in experimental Hall C. The measurements were designed to extend the highest energy differential cross section values to 5.5 GeV incident photon energy at forward angles. This builds upon previous high energy measurements in which scaling consistent with the pQCD constituent counting rules was observed at 90 degrees and 70 degrees in the center of mass. From the new measurements, a threshold for the onset of constituent counting rule scaling seems present at transverse momentum approximately 1.3 GeV/c. The second experiment, E99-008, was performed in experimental Hall A. The measurements were designed to explore the angular distribution of the differential cross section at constant energy. The measurements were made symmetric about 90 degrees

  8. Double-differential heavy-ion production cross sections.

    PubMed

    Miller, T M; Townsend, L W

    2004-01-01

    Current computational tools used for space or accelerator shielding studies transport energetic heavy ions either using a one-dimensional straight-ahead approximation or by dissociating the nuclei into protons and neutrons and then performing neutron and proton transport using Monte Carlo techniques. Although the heavy secondary particles generally travel close to the beam direction, a proper treatment of the light ions produced in these reactions requires that double-differential cross sections should be utilised. Unfortunately, no fundamental nuclear model capable of serving as an event generator to provide these cross sections for all ions and energies of interest exists currently. Herein, we present a model for producing double-differential heavy-ion production cross sections that uses heavy-ion fragmentation yields produced by the NUCFRG2 fragmentation code coupled with a model of energy degradation in nucleus-nucleus collisions and systematics of momentum distributions to provide energy and angular dependences of the heavy-ion production.

  9. Dosimetry and cross section measurements at RTNS II

    SciTech Connect

    Greenwood, L.R.; Kneff, D.W.

    1987-01-01

    Numerous measurements have been conducted at TRNS-II in order to map the neutron field for materials irradiations, to measure activation cross sections, and to measure helium production cross sections. Experiments of up to two weeks duration irradiated large numbers of activation dosimetry and helium samples both close to the source and throughout the target room. Many other samples have been irradiated in piggy-back positions over periods lasting many months. All of these experiments fall into four main classes, namely, fluence-mapping, activation dosimetry, the production of long-lived isotopes, and helium generation measurements. Radiometric dosimetry and activation cross section measurements were performed at Argonne National Laboratory; helium production was measured at Rockwell International Corporation. This paper briefly summarizes the principal results of our measurements at RTNS-II; references are given for more detailed publications. 14 refs., 4 figs.

  10. Cross section versus time delay and trapping probability

    NASA Astrophysics Data System (ADS)

    Luna-Acosta, G. A.; Fernández-Marín, A. A.; Méndez-Bermúdez, J. A.; Poli, Charles

    2016-07-01

    We study the behavior of the s-wave partial cross section σ (k), the Wigner-Smith time delay τ (k), and the trapping probability P (k) as function of the wave number k. The s-wave central square well is used for concreteness, simplicity, and to elucidate the controversy whether it shows true resonances. It is shown that, except for very sharp structures, the resonance part of the cross section, the trapping probability, and the time delay, reach their local maxima at different values of k. We show numerically that τ (k) > 0 at its local maxima, occurring just before the resonant part of the cross section reaches its local maxima. These results are discussed in the light of the standard definition of resonance.

  11. Inelastic cross sections for positron scattering from atomic hydrogen

    SciTech Connect

    Weber, M.; Hofmann, A.; Raith, W.; Sperber, W.; Jacobsen, F.; Lynn, K.G.

    1994-12-31

    Positronium formation (Ps) cross sections for positrons impinging on atomic hydrogen were measured in the impact energy range from 13eV to 255eV at the High Intensity Positron (HIP) beam at Brookhaven National Laboratory (BNL). The Ps-formation cross section was found to rise rapidly from the threshold at 6.8eV to a maximum value of (2.98 {plus_minus} 0.18) {times} 10{sup {minus}16} cm{sup 2} for {approx} 15eV positrons. By 75eV it drops below the detection limit of 0.17 {times} 10{sup {minus}16} cm{sup 2} which is the present level of statistical uncertainty. The experiment was modified to enable the measurement of doubly differential scattering cross sections.

  12. Cross-Sectional Transport Imaging in a Multijunction Solar Cell

    SciTech Connect

    Haegel, Nancy M.; Ke, Chi-Wen; Taha, Hesham; Guthrey, Harvey; Fetzer, C. M.; King, Richard

    2015-06-14

    Combining highly localized electron-beam excitation at a point with the spatial resolution capability of optical near-field imaging, we have imaged carrier transport in a cross-sectioned multijunction (GaInP/GaInAs/Ge) solar cell. We image energy transport associated with carrier diffusion throughout the full width of the middle (GaInAs) cell and luminescent coupling from point excitation in the top cell GaInP to the middle cell. Supporting cathodoluminescence and near-field photoluminescence measurements demonstrate excitation-dependent Fermi level splitting effects that influence cross-sectioned spectroscopy results as well as transport limitations on the spatial resolution of cross-sectional measurements.

  13. Pion Total Cross Section in Nucleon - Nucleon Collisions

    NASA Technical Reports Server (NTRS)

    Norbury, John W.

    2009-01-01

    Total cross section parameterizations for neutral and charged pion production in nucleon - nucleon collisions are compared to experimental data over the projectile momentum range from threshold to 300 GeV. Both proton - proton and proton - neutron reactions are considered. Overall excellent agreement between parameterizations and experiment is found, except for notable disagreements near threshold. In addition, the hypothesis that the neutral pion production cross section can be obtained from the average charged pion cross section is checked. The theoretical formulas presented in the paper obey this hypothesis for projectile momenta below 500 GeV. The results presented provide a test of engineering tools used to calculate the pion component of space radiation.

  14. Recent advances in modeling fission cross sections over intermediate structures

    SciTech Connect

    Bouland, Olivier; Lynn, J. Eric; Talou, Patrick

    2009-01-01

    More accurate fission cross section calculations in presence of underlying intermediate structure are strongly desired. This paper recalls the common approximations used below the fission threshold and quantifies their impact. In particular, an exact expanded R-matrix Monte Carlo calculation of the intermediate structure, deeply mixed with the fluctuations of the class-I and II decay amplitudes, is shown. This paper also insists on the microscopic structure of the level densities as a function of the nucleus deformation and show preliminary neutron induced fission cross section calculations for {sup 239}Pu and {sup 240}Pu using newly calculated combinatorial level densities. Comparisons with recent evaluated and measured fission cross sections are made.

  15. The use of cross-section warping functions in composite rotor blade analysis

    NASA Technical Reports Server (NTRS)

    Kosmatka, J. B.

    1992-01-01

    During the contracted period, our research was concentrated into three areas. The first was the development of an accurate and a computationally efficient method for predicting the cross-section warping functions in an arbitrary cross-section composed of isotropic and/or anisotropic materials. The second area of research was the development of a general higher-order one-dimensional theory for anisotropic beams. The third area of research was the development of an analytical model for assessing the extension-bend-twist coupling behavior of nonhomogeneous anisotropic beams with initial twist. In the remaining six chapters of this report, the three different research areas and associated sub-research areas are covered independently including separate introductions, theoretical developments, numerical results, and references.

  16. Inclusive jet cross sections and jet shapes at CDF

    SciTech Connect

    Wainer, N.

    1991-09-01

    The inclusive jet cross section and jet shapes at {radical}s = 1.8 TeV have been measured by CDF at the Fermilab Tevatron Collider. results are compared to recent next-to-leading order QCD calculations, which predict variation of the cross section with cone size, as well as variation of the jet shape with energy. A lower limit on the parameter {Lambda}{sub c}, which characterize a contact interaction associated with quark sub-structure is determined to be 1400 GeV at the 95% confidence level. 3 refs., 4 figs.

  17. Neutron capture cross section standards for BNL 325, Fourth Edition

    SciTech Connect

    Holden, N.E.

    1981-01-01

    This report evaluates the experimental data and recommends values for the thermal neutron cross sections and resonance integrals for the neutron capture reactions: /sup 55/Mn(n,..gamma..), /sup 59/Co(n,..gamma..) and /sup 197/Au(n,..gamma..). The failure of lithium and boron as standards due to the natural variation of the absorption cross sections of these elements is discussed. The Westcott convention, which describes the neutron spectrum as a thermal Maxwellian distribution with an epithermal component, is also discussed.

  18. Light ray tracing through a leaf cross section

    NASA Technical Reports Server (NTRS)

    Kumar, R.; Silva, L. F.

    1973-01-01

    A light ray, incident at about 5 deg to the normal, is geometrically plotted through the drawing of the cross section of a soybean leaf using Fresnel's equations and Snell's law. The optical mediums of the leaf considered for ray tracing are: air, cell sap, chloroplast, and cell wall. The ray is also drawn through the same leaf cross section with cell wall and air as the only optical mediums. The values of the reflection and transmission found from the ray tracing tests agree closely with the experimental results obtained using a Beckman Dk-2A Spectroreflector.

  19. Light ray tracing through a leaf cross section

    NASA Technical Reports Server (NTRS)

    Kumar, R.; Silva, L.

    1973-01-01

    A light ray, incident at about 5 deg to the normal, is geometrically plotted through the drawing of the cross section of a soybean leaf using Fresnel's equations and Snell's law. The optical mediums of the leaf considered for ray tracing are air, cell sap, chloroplast, and cell wall. The above ray is also drawn through the same leaf cross section considering cell wall and air as the only optical mediums. The values of the reflection and transmission found from ray tracing agree closely with the experimental results obtained using a Beckman DK-2A spectroreflectometer.

  20. Uncertainty Quantification in Fission Cross Section Measurements at LANSCE

    SciTech Connect

    Tovesson, F.

    2015-01-15

    Neutron-induced fission cross sections have been measured for several isotopes of uranium and plutonium at the Los Alamos Neutron Science Center (LANSCE) over a wide range of incident neutron energies. The total uncertainties in these measurements are in the range 3–5% above 100 keV of incident neutron energy, which results from uncertainties in the target, neutron source, and detector system. The individual sources of uncertainties are assumed to be uncorrelated, however correlation in the cross section across neutron energy bins are considered. The quantification of the uncertainty contributions will be described here.

  1. SU-E-I-43: Photoelectric Cross Section Revisited

    SciTech Connect

    Haga, A; Nakagawa, K; Kotoku, J; Horikawa, Y

    2015-06-15

    Purpose: The importance of the precision in photoelectric cross-section value increases for recent developed technology such as dual energy computed tomography, in which some reconstruction algorithms require the energy dependence of the photo-absorption in each material composition of human being. In this study, we revisited the photoelectric cross-section calculation by self-consistent relativistic Hartree-Fock (HF) atomic model and compared with that widely distributed as “XCOM database” in National Institute of Standards and Technology, which was evaluated with localdensity approximation for electron-exchange (Fock)z potential. Methods: The photoelectric cross section can be calculated with the electron wave functions in initial atomic state (bound electron) and final continuum state (photoelectron). These electron states were constructed based on the selfconsistent HF calculation, where the repulsive Coulomb potential from the electron charge distribution (Hartree term) and the electron exchange potential with full electromagnetic interaction (Fock term) were included for the electron-electron interaction. The photoelectric cross sections were evaluated for He (Z=2), Be (Z=4), C (Z=6), O (Z=8), and Ne (Z=10) in energy range of 10keV to 1MeV. The Result was compared with XCOM database. Results: The difference of the photoelectric cross section between the present calculation and XCOM database was 8% at a maximum (in 10keV for Be). The agreement tends to be better as the atomic number increases. The contribution from each atomic shell has a considerable discrepancy with XCOM database except for K-shell. However, because the photoelectric cross section arising from K-shell is dominant, the net photoelectric cross section was almost insensitive to the different handling in Fock potential. Conclusion: The photoelectric cross-section program has been developed based on the fully self-consistent relativistic HF atomic model. Due to small effect on the Fock

  2. Inclusive jet cross section measurement at D0

    SciTech Connect

    Voutilainen, M.; /Nebraska U. /Helsinki Inst. of Phys.

    2006-09-01

    We present a new preliminary measurement of the inclusive jet cross section in p{bar p} collisions based on a integrated luminosity of about 0.8 fb{sup -1}. The data were acquired using the D0 detector between 2002 and 2005. Jets are reconstructed using an iterative cone algorithm with radius R{sub cone} = 0.7. The inclusive jet cross section is presented as a function of transverse jet momentum and rapidity. Predictions from perturbative QCD in next-to-leading order, plus threshold corrections in 2-loop accuracy describe the shape in the transverse jet momentum.

  3. Improved Actinide Neutron Capture Cross Sections Using Accelerator Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Bauder, W.; Pardo, R. C.; Kondev, F. G.; Kondrashev, S.; Nair, C.; Nusair, O.; Palchan, T.; Scott, R.; Seweryniak, D.; Vondrasek, R.; Collon, P.; Paul, M.; Youinou, G.; Salvatores, M.; Palmotti, G.; Berg, J.; Maddock, T.; Imel, G.

    2014-09-01

    The MANTRA (Measurement of Actinide Neutron TRAnsmutations) project will improve energy-integrated neutron capture cross section data across the actinide region. These data are incorporated into nuclear reactor models and are an important piece in understanding Generation IV reactor designs. We will infer the capture cross sections by measuring isotopic ratios from actinide samples, irradiated in the Advanced Test Reactor at INL, with Accelerator Mass Spectrometry (AMS) at ATLAS (ANL). The superior sensitivity of AMS allows us to extract multiple cross sections from a single sample. In order to analyze the large number of samples needed for MANTRA and to meet the goal of extracting multiple cross sections per sample, we have made a number of modifications to the AMS setup at ATLAS. In particular, we are developing a technique to inject solid material into the ECR with laser ablation. With laser ablation, we can better control material injection and potentially increase efficiency in the ECR, thus creating less contamination in the source and reducing cross talk. I will present work on the laser ablation system and preliminary results from our AMS measurements. The MANTRA (Measurement of Actinide Neutron TRAnsmutations) project will improve energy-integrated neutron capture cross section data across the actinide region. These data are incorporated into nuclear reactor models and are an important piece in understanding Generation IV reactor designs. We will infer the capture cross sections by measuring isotopic ratios from actinide samples, irradiated in the Advanced Test Reactor at INL, with Accelerator Mass Spectrometry (AMS) at ATLAS (ANL). The superior sensitivity of AMS allows us to extract multiple cross sections from a single sample. In order to analyze the large number of samples needed for MANTRA and to meet the goal of extracting multiple cross sections per sample, we have made a number of modifications to the AMS setup at ATLAS. In particular, we are

  4. Uncertainty quantification in fission cross section measurements at LANSCE

    DOE PAGES

    Tovesson, F.

    2015-01-09

    Neutron-induced fission cross sections have been measured for several isotopes of uranium and plutonium at the Los Alamos Neutron Science Center (LANSCE) over a wide range of incident neutron energies. The total uncertainties in these measurements are in the range 3–5% above 100 keV of incident neutron energy, which results from uncertainties in the target, neutron source, and detector system. The individual sources of uncertainties are assumed to be uncorrelated, however correlation in the cross section across neutron energy bins are considered. The quantification of the uncertainty contributions will be described here.

  5. Measurement of a metastability-exchange cross section in krypton

    SciTech Connect

    Brechignac, C.; Vetter, R.

    1980-08-01

    The metastability-exchange cross section between (/sup 3/P/sub 2/)Kr atoms and (/sup 1/S/sub 0/)Kr atoms is measured by means of a two-laser saturated-absorption experiment performed on the lambda=557-nm transition. A study of velocity changes occurring in pure /sup 86/Kr and in (/sup 86/Kr--/sup 78/Kr) discharges leads to a value for the cross section Q75=(plus-or-minus10) A/sup 2/.

  6. Inelastic cross sections from gamma-ray measurements

    SciTech Connect

    Nelson, Ronald Owen

    2010-12-06

    Measurements of gamma rays following neutron induced reactions have been studied with the Germanium Array for Neutron-induced Excitations (GEANIE) at the Los Alamos Neutron Science Center (LANSCE) for many years. Gamma-ray excitation functions and coincidence studies provide insight into nuclear reaction mechanisms as well as expanding our knowledge of energy levels and gamma-rays. Samples studied with Ge detectors at LANSCE range from Be to Pu. Fe, Cr and Ti have been considered for use as reference cross sections. An overview of the measurements and efforts to create a reliable neutron-induced gamma-ray reference cross section will be presented.

  7. Total cross section of electron scattering by fluorocarbon molecules

    NASA Astrophysics Data System (ADS)

    Yamada, T.; Ushiroda, S.; Kondo, Y.

    2008-12-01

    A compact linear electron transmission apparatus was used for the measurement of the total electron scattering cross section at 4-500 eV. Total cross sections of chlorofluorocarbon (CCl2F2), hydrochlorofluorocarbon (CHClF2), perfluoropropane (C3F8), perfluoro-n-pentane (C5F12), perfluoro-n-hexane (C6F14) and perfluoro-n-octane (C8F18) were obtained experimentally and compared with the values obtained from a theoretical calculation and semi-empirical model calculation.

  8. Evaluation of the /sup 238/U neutron total cross section

    SciTech Connect

    Smith, A.; Poenitz, W.P.; Howerton, R.J.

    1982-12-01

    Experimental energy-averaged neutron total cross sections of /sup 238/U were evaluated from 0.044 to 20.0 MeV using regorous numerical methods. The evaluated results are presented together with the associated uncertainties and correlation matrix. They indicate that this energy-averaged neutron total cross section is known to better than 1% over wide energy regions. There are somwewhat larger uncertainties at low energies (e.g., less than or equal to 0.2 MeV), near 8 MeV and above 15 MeV. The present evaluation is compard with values given in ENDF/B-V.

  9. Fast-neutron scattering cross sections of elemental zirconium

    SciTech Connect

    Smith, A.B.; Guenther, P.T.

    1982-12-01

    Differential neturon-elastic-scattering cross sections of elemental zirconium are measured from 1.5 to 4.0 MeV at intervals of less than or equal to 200 keV. Inelastic-neutron-scattering cross sections corresponding to the excitation of levels at observed energies of: 914 +- 25, 1476 +- 37, 1787 +- 23, 2101 +- 26, 2221 +- 17, 2363 +- 14, 2791 +- 15 and 3101 +- 25 keV are determined. The experimental results are interpreted in terms of the optical-statistical model and are compared with corresponding quantities given in ENDF/B-V.

  10. Hadronic absorption cross sections of B{sub c}

    SciTech Connect

    Lodhi, M. A. K.; Akram, Faisal; Irfan, Shaheen

    2011-09-15

    The cross sections of B{sub c} absorption by {pi} mesons are calculated using a hadronic Lagrangian based on the SU(5) flavor symmetry. Calculated cross sections are found to be in the ranges 2-7 mb and 0.2-2 mb for the processes B{sub c}{sup +}{pi}{yields}DB and B{sub c}{sup +}{pi}{yields}D*B*, respectively, when the monopole form factor is included. These results could be useful in calculating the production rate of B{sub c} mesons in relativistic heavy ion collisions.

  11. Differential Cross Sections for Proton-Proton Elastic Scattering

    NASA Technical Reports Server (NTRS)

    Norman, Ryan B.; Dick, Frank; Norbury, John W.; Blattnig, Steve R.

    2009-01-01

    Proton-proton elastic scattering is investigated within the framework of the one pion exchange model in an attempt to model nucleon-nucleon interactions spanning the large range of energies important to cosmic ray shielding. A quantum field theoretic calculation is used to compute both differential and total cross sections. A scalar theory is then presented and compared to the one pion exchange model. The theoretical cross sections are compared to proton-proton scattering data to determine the validity of the models.

  12. Review of Current and Future Neutrino Cross-Section Experiments

    SciTech Connect

    Schmitz, D.; /Fermilab

    2009-07-01

    There has been a surge of progress and published results in neutrino cross-section physics in recent years. In many cases, absolute differential cross-sections are being measured for the first time and can be compared to interaction models first developed decades ago. These measurements are important input for the next generation of accelerator-based neutrino oscillation experiments where precise understanding of both signal and background channels will be critical to the observation of sub-dominant oscillation effects. This paper discusses recent results from several experiments and describes new experiments currently under construction dedicated to making these measurements with unprecedented precision.

  13. Review of Current and Future Neutrino Cross-Section Experiments

    SciTech Connect

    Schmitz, D.

    2010-03-30

    There has been a surge of progress and published results in neutrino cross-section physics in recent years. In many cases, absolute differential cross-sections are being measured for the first time and can be compared to interaction models first developed decades ago. These measurements are important input for the next generation of accelerator-based neutrino oscillation experiments where precise understanding of both signal and background channels will be critical to the observation of sub-dominant oscillation effects. This paper discusses recent results from several experiments and describes new experiments currently under construction dedicated to making these measurements with unprecedented precision.

  14. Automated image segmentation of haematoxylin and eosin stained skeletal muscle cross-sections

    PubMed Central

    LIU, F.; MACKEY, A.L.; SRIKUEA, R.; ESSER, K.A.; YANG, L.

    2014-01-01

    Summary The ability to accurately and efficiently quantify muscle morphology is essential to determine the physiological relevance of a variety of muscle conditions including growth, atrophy and repair. There is agreement across the muscle biology community that important morphological of characteristics of muscle fibres, such as cross-sectional area, are critical factors that determine the health and function (e.g. quality) of the muscle. However, at this time, quantification of muscle characteristics, especially from haematoxylin and eosin stained slides, is still a manual or semi-automatic process. This procedure is labour-intensive and time-consuming. In this paper, we have developed and validated an automatic image segmentation algorithm that is not only efficient but also accurate. Our proposed automatic segmentation algorithm for haematoxylin and eosin stained skeletal muscle cross-sections consists of two major steps: (1) A learning-based seed detection method to find the geometric centres of the muscle fibres, and (2) a colour gradient repulsive balloon snake deformable model that adopts colour gradient in Luv colour space. Automatic quantification of muscle fibre cross-sectional areas using the proposed method is accurate and efficient, providing a powerful automatic quantification tool that can increase sensitivity, objectivity and efficiency in measuring the morphometric features of the haematoxylin and eosin stained muscle cross-sections. PMID:24118017

  15. Hindlimb suspension diminishes femoral cross-sectional growth in the rat

    NASA Technical Reports Server (NTRS)

    van der Meulen, M. C.; Morey-Holton, E. R.; Carter, D. R.

    1995-01-01

    Growth, functional adaptation, and torsional strength were examined in the femora of 39-day-old male Sprague-Dawley rats subjected to hindlimb suspension for 0, 1, 2, 3, or 4 weeks and were compared with measurements for age-matched control animals. Our goal was to understand the effect of reduced loading on the normal age-related changes in femoral properties during growth. The control animals exhibited growth-related increases in all geometric and torsional properties of the femur. The mean body mass and femoral length of the hindlimb-suspended rats were similar to those of the controls throughout the experiment. Over 4 weeks, the femoral cross-sectional and torsional measurements from the hindlimb-suspended rats demonstrated increases in comparison with the basal values (+33% cross-sectional area, +64% polar moment of inertia, +67% ultimate torque, and +181% torsional rigidity), but the age-matched controls showed significantly greater growth-related increases (+71% cross-sectional area, +136% polar moment of inertia, +127% ultimate torque, and +367% torsional rigidity). The differences in femoral structural strength between the hindlimb-suspended animals and the age-matched controls were attributable to differences in altered cross-sectional geometry.

  16. Effect of finite range of the NN force and NN cross section on reaction cross section for neutron rich nuclei

    SciTech Connect

    Ismail, M.; Ellithi, A.Y.; Abou-Shady, H.

    2005-02-01

    The reaction cross section ({sigma}{sub R}) is calculated using the optical limit of the Glauber theory. A density-dependent effective nucleon-nucleon (NN) cross section {sigma}{sub NN} is considered. Finite and zero range NN interactions are studied. The effect of finite range and an appropriate local density can increase {sigma}{sub R} up to 20% compared to the zero range at constant density (0.16 fm{sup -3}), while a zero range calculation with free NN cross section increases {sigma}{sub R} up to 13%. These factors affect the values of the rms radii for neutron rich nuclei extracted from {sigma}{sub R}.

  17. The effect of asthma on the perimeter of the airway basement membrane.

    PubMed

    Elliot, John G; Budgeon, Charley A; Harji, Salima; Jones, Robyn L; James, Alan L; Green, Francis H

    2015-11-15

    When comparing the pathology of airways in individuals with and without asthma, the perimeter of the basement membrane (Pbm) is used as a marker of airway size, as it is independent of airway smooth muscle shortening or airway collapse. The extent to which the Pbm is itself altered in asthma has not been quantified. The aim of this study was to compare the Pbm from the same anatomical sites in postmortem lungs from subjects with (n = 55) and without (n = 30) asthma (nonfatal or fatal). Large and small airways were systematically sampled at equidistant "levels" from the apical segment of the left upper lobes and anterior and basal segments of the left lower lobes of lungs fixed in inflation. The length of the Pbm was estimated from cross sections of airway at each relative level. Linear mixed models were used to investigate the relationships between Pbm and sex, age, height, smoking status, airway level, and asthma group. The final model showed significant interactions between Pbm and airway level in small (<3 mm) airways, in subjects having asthma (P < 0.0001), and by sex (P < 0.0001). No significant interactions for Pbm between asthma groups were observed for larger airways (equivalent to a diameter of ∼3 mm and greater) or smoking status. Asthma is not associated with remodeling of the Pbm in large airways. In medium and small airways, the decrease in Pbm in asthma (≤20%) would not account for the published differences in wall area or area of smooth muscle observed in cases of severe asthma.

  18. A Cross-Sectional Study of Cognitive Variables.

    ERIC Educational Resources Information Center

    Grippin, Pauline; And Others

    Students in grades K, 1, 3, and 5 were administered the Rod and Frame Test (RFT), the Matching Familiar Figures (MFF) Test, and the Piagetian tasks of Discontinuous Quantity, Class Inclusion, Multiplication of Classes, and Multiplication of Relations. Cross-sectional trends were found in all tasks with older children being less impulsive, more…

  19. Measurement campaign for astrophysically relevant 36Cl production cross sections

    NASA Astrophysics Data System (ADS)

    Anderson, Tyler; Skulski, Michael; Ostdiek, Karen; Lu, Wenting; Beard, Mary; Collon, Philippe

    2015-10-01

    The short-lived radionuclide 36Cl (t1/2 = 0.301 Ma) is known to have existed in the Early Solar System (ESS), and evaluating its production sources can lead to better understanding of the processes taking place in ESS formation and their timescales. The x-wind production model is used to explain 36Cl production via solar energetic particles from the young Sun, but is lacking empirical data for many relevant reactions. Bowers et al. (2013) measured the cross section of 33S(α,p)36Cl at various energies in the range of 0.70-2.42 MeV/A, and found them to be systematically under predicted by statistical Hauser-Feshbach model codes TALYS and NON-SMOKER, highlighting the need for more empirical data for these cross sections. A recent paper by Mohr (2013) called these results in to question, prompting the re-measurement of the cross section for 33S(α,p)36Cl at new energies in the same energy range as Bowers et al. This talk will also discuss two further planned measurements of cross sections suggested by Bowers et al. to be the next most significant in 36Cl production.

  20. RZ calculations for self shielded multigroup cross sections

    SciTech Connect

    Li, M.; Sanchez, R.; Zmijarevic, I.; Stankovski, Z.

    2006-07-01

    A collision probability method has been implemented for RZ geometries. The method accounts for white albedo, specular and translation boundary condition on the top and bottom surfaces of the geometry and for a white albedo condition on the outer radial surface. We have applied the RZ CP method to the calculation of multigroup self shielded cross sections for Gadolinia absorbers in BWRs. (authors)

  1. 10. Photograph of a line drawing. SHEET 10, CROSS SECTION ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. Photograph of a line drawing. SHEET 10, CROSS SECTION BB; 9-16-1940. Assembly Building for Tank Plant for the Chrysler Corporation, Macomb County, Michigan. Delineator: S.B. - Detroit Arsenal, 6501 East Eleven Mile Road, Warren, Macomb County, MI

  2. 8. Photograph of a line drawing. SHEET 8, CROSS SECTION ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. Photograph of a line drawing. SHEET 8, CROSS SECTION ON LINE EE; 9-16-1940. Assembly Building for Tank Plant for the Chrysler Corporation, Macomb County, Michigan. Delineator: E.B. - Detroit Arsenal, 6501 East Eleven Mile Road, Warren, Macomb County, MI

  3. 7. Photograph of a line drawing. SHEET 7, CROSS SECTION ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. Photograph of a line drawing. SHEET 7, CROSS SECTION ON LINE CC AND DD; 9-16-1940. Assembly Building for Tank Plant for the Chrysler Corporation, Macomb County, Michigan. Delineator: E.B. - Detroit Arsenal, 6501 East Eleven Mile Road, Warren, Macomb County, MI

  4. C+C Fusion Cross Sections Measurements for Nuclear Astrophysics

    SciTech Connect

    Almaraz-Calderon, S.; Carnelli, P. F. F.; Rehm, K. E.; Albers, M.; Alcorta, M.; Bertone, P. F.; Digiovine, B.; Esbensen, H.; Fernandez Niello, J. O.; Henderson, D.; Jiang, C. L.; Lai, J.; Marley, S. T.; Nusair, O.; Palchan-Hazan, T.; Pardo, R. C.; Paul, M.; Ugalde, C.; Giardina, G.; Eidelman, S.; Venanzoni, G.; Battaglieri, M.; Mandaglio, G.

    2015-06-02

    Total fusion cross section of carbon isotopes were obtained using the newly developed MUSIC detector. MUSIC is a highly efficient, active target-detector system designed to measure fusion excitation functions with radioactive beams. The present measurements are relevant for understanding x-ray superbursts. The results of the first MUSIC campaign as well as the astrophysical implications are presented in this work.

  5. 44. CROSS SECTION OF GRAND CANAL (not to scale, but ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    44. CROSS SECTION OF GRAND CANAL (not to scale, but representative of all six canals) Plan Sheet D-29976, Venice Canals Rehabilitation, Sheet No. 7 of 26 (delineated by T. Wu and E. Lee, March 1991) - Venice Canals, Community of Venice, Los Angeles, Los Angeles County, CA

  6. 35. 'Firing Pier, Cross Sections, Looking South,' submitted 29 December ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    35. 'Firing Pier, Cross Sections, Looking South,' submitted 29 December 1941 by John Brackett, Consulting Engineer, to Public Works Department, Bureau of Yards & Docks. PW Drawing 3874-46, Y&D Drawing 190848. Scale 1/8' = 1'. - Naval Torpedo Station, Firing Pier, North end of Gould Island in Narragansett Bay, Newport, Newport County, RI

  7. 11. Photograph of a line drawing. 'CROSS SECTION OF GAS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    11. Photograph of a line drawing. 'CROSS SECTION OF GAS PRODUCER.' From George R. Cooper (Wilputte Corporation). 'Operating Overview of a Producer Gas Plant (12 Machines) at Kingsport, Tennessee.' Presented at the Fifth Annual International Conference on Coal Gasification, Liquefaction and Conversion to Electricity. University of Pittsburgh, August 2, 1978. - Holston Army Ammunition Plant, Producer Gas Plant, Kingsport, Sullivan County, TN

  8. Cross Sections: No 6 Hold Section at Fr 178 Looking ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Cross Sections: No 6 Hold Section at Fr 178 Looking Fwd, No 7 Hold Section at No 154 Looking Fwd, No 7 Hold Section at Fr 195 Looking Fwd Showing Trans 194, No 7 Hold Section at Fr 198 Looking Fwd - General John Pope, Suisun Bay Reserve Fleet, Benicia, Solano County, CA

  9. Cross Sections: No. 1 Hold section at Fr 24 Looking ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Cross Sections: No. 1 Hold section at Fr 24 Looking Fwd, No 1 Hold Section at Fr 28 Looking Aft, No 2 Hold Section at Fr 48 Looking Aft, No 3 Hold Section at Fr 70 Looking Aft, No 4 Hold Section at Fr 90 Looking Aft - General John Pope, Suisun Bay Reserve Fleet, Benicia, Solano County, CA

  10. Absolute photoionization cross-section of the propargyl radical

    SciTech Connect

    Savee, John D.; Welz, Oliver; Taatjes, Craig A.; Osborn, David L.; Soorkia, Satchin; Selby, Talitha M.

    2012-04-07

    Using synchrotron-generated vacuum-ultraviolet radiation and multiplexed time-resolved photoionization mass spectrometry we have measured the absolute photoionization cross-section for the propargyl (C{sub 3}H{sub 3}) radical, {sigma}{sub propargyl}{sup ion}(E), relative to the known absolute cross-section of the methyl (CH{sub 3}) radical. We generated a stoichiometric 1:1 ratio of C{sub 3}H{sub 3} : CH{sub 3} from 193 nm photolysis of two different C{sub 4}H{sub 6} isomers (1-butyne and 1,3-butadiene). Photolysis of 1-butyne yielded values of {sigma}{sub propargyl}{sup ion}(10.213 eV)=(26.1{+-}4.2) Mb and {sigma}{sub propargyl}{sup ion}(10.413 eV)=(23.4{+-}3.2) Mb, whereas photolysis of 1,3-butadiene yielded values of {sigma}{sub propargyl}{sup ion}(10.213 eV)=(23.6{+-}3.6) Mb and {sigma}{sub propargyl}{sup ion}(10.413 eV)=(25.1{+-}3.5) Mb. These measurements place our relative photoionization cross-section spectrum for propargyl on an absolute scale between 8.6 and 10.5 eV. The cross-section derived from our results is approximately a factor of three larger than previous determinations.

  11. Predictions of diffractive cross sections in proton-proton collisions

    SciTech Connect

    Goulianos, Konstantin

    2013-04-15

    We review our pre-LHC predictions of the total, elastic, total-inelastic, and diffractive components of proton-proton cross sections at high energies, expressed in the form of unitarized expressions based on a special parton-model approach to diffraction employing inclusive proton parton distribution functions and QCD color factors and compare with recent LHC results.

  12. Service building. Cross section thru dry dock nos. 4 & ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Service building. Cross section thru dry dock nos. 4 & 5 showing service bldg & 20-75-150 ton cranes (dry dock associates, May 23, 1941). In files of Cushman & Wakefield, building no. 501, Philadelphia Naval Business Center. - Naval Base Philadelphia-Philadelphia Naval Shipyard, Service Building, Dry Docks No. 4 & 5, League Island, Philadelphia, Philadelphia County, PA

  13. Elastic photonuclear cross sections for bremsstrahlung from relativistic ions

    NASA Astrophysics Data System (ADS)

    Mikkelsen, Rune E.; Sørensen, Allan H.; Uggerhøj, Ulrik I.

    2016-04-01

    In this paper, we provide a procedure to calculate the bremsstrahlung spectrum for virtually any relativistic bare ion with charge 6e or beyond, Z ⩾ 6 , in ultraperipheral collisions with target nuclei. We apply the Weizsäcker-Williams method of virtual quanta to model the effect of the distribution of nuclear constituents on the interaction of the ion with the radiation target. This leads to a bremsstrahlung spectrum peaking at 2 γ times the energy of the giant dipole resonance (γ is the projectile energy in units of its rest energy). A central ingredient in the calculation is the cross section for elastic scattering of photons on the ion. This is only available in the literature for a few selected nuclei and, usually, only in a rather restricted parameter range. Hence we develop a procedure applicable for all Z ⩾ 6 to estimate the elastic scattering. The elastic cross section is obtained at low to moderate photon energies, somewhat beyond the giant dipole resonance, by means of the optical theorem, a dispersion relation, and data on the total absorption cross section. The cross section is continued at higher energies by invoking depletion due to loss of coherence in the scattering. Our procedure is intended for any ion where absorption data is available and for moderate to high energies, γ ≳ 10 .

  14. Measurement of proton inelastic scattering cross sections on fluorine

    NASA Astrophysics Data System (ADS)

    Chiari, M.; Caciolli, A.; Calzolai, G.; Climent-Font, A.; Lucarelli, F.; Nava, S.

    2016-10-01

    Differential cross-sections for proton inelastic scattering on fluorine, 19F(p,p')19F, from the first five excited levels of 19F at 110, 197, 1346, 1459 and 1554 keV were measured for beam energies from 3 to 7 MeV at a scattering angle of 150° using a LiF thin target (50 μg/cm2) evaporated on a self-supporting C thin film (30 μg/cm2). Absolute differential cross-sections were calculated with a method not dependent on the absolute values of collected beam charge and detector solid angle. The validity of the measured inelastic scattering cross sections was then tested by successfully reproducing EBS spectra collected from a thick Teflon (CF2) target. As a practical application of these measured inelastic scattering cross sections in elastic backscattering spectroscopy (EBS), the feasibility of quantitative light element (C, N and O) analysis in aerosol particulate matter samples collected on Teflon by EBS measurements and spectra simulation is demonstrated.

  15. Electron-Impact Total Ionization Cross Section of Rb.

    NASA Astrophysics Data System (ADS)

    Kim, Y.-K.; Migdalek, J.; Siegel, W.; Bieroń, J.

    1997-04-01

    The Binary-Encounter-Dipole (BED) model(Y.-K. Kim and M.E. Rudd, Phys. Rev. A 50), 3954 (1994). has been applied to electron-impact ionization of Rb. The BED cross section is in good agreement with a recent experimental data.(R.S. Schappe et al., Phys. Rev. Lett. 76), 4328 (1996). The BED theory combines a modified Mott cross section with the high-incident energy behavior of the Born cross section. The required continuum f-values were calculated from Dirac-Fock continuum wave functions with a core polarization potential.(J. Migdalek and W.E. Baylis, J. Phys. B 11), L497 (1978). The cut-off radius of the matching dipole transition operator was adjusted to reproduce the position of the known minimum in the photoionization cross section.(H. Suemitsu and J.A.R. Samson, Phys. Rev. 28), 2752 (1983). The contributions of the 4p arrow 4d, 5s, and 5p autoionizing excitations were included using the plane-wave Born approximation. We also present f-values for the 5s arrow np_1/2, np_3/2 transitions for high n near the ionization threshold.

  16. Neutron capture cross section of {sup 241}Am

    SciTech Connect

    Jandel, M.; Bredeweg, T. A.; Bond, E. M.; Chadwick, M. B.; Clement, R. R.; Couture, A.; O'Donnell, J. M.; Haight, R. C.; Kawano, T.; Reifarth, R.; Rundberg, R. S.; Ullmann, J. L.; Vieira, D. J.; Wilhelmy, J. B.; Wouters, J. M.; Agvaanluvsan, U.; Parker, W. E.; Wu, C. Y.; Becker, J. A.

    2008-09-15

    The neutron capture cross section of {sup 241}Am for incident neutrons from 0.02 eV to 320 keV has been measured with the detector for advanced neutron capture experiments (DANCE) at the Los Alamos Neutron Science Center. The thermal neutron capture cross section was determined to be 665{+-}33 b. Our result is in good agreement with other recent measurements. Resonance parameters for E{sub n}<12 eV were obtained using an R-matrix fit to the measured cross section. The results are compared with values from the ENDF/B-VII.0, Mughabghab, JENDL-3.3, and JEFF-3.1 evaluations. {gamma}{sub n} neutron widths for the first three resonances are systematically larger by 5-15% than the ENDF/B-VII.0 values. The resonance integral above 0.5 eV was determined to be 1553{+-}7 b. Cross sections in the resolved and unresolved energy regions above 12 eV were calculated using the Hauser-Feshbach theory incorporating the width-fluctuation correction of Moldauer. The calculated results agree well with the measured data, and the extracted averaged resonance parameters in the unresolved resonance region are consistent with those for the resolved resonances.

  17. Accurate momentum transfer cross section for the attractive Yukawa potential

    SciTech Connect

    Khrapak, S. A.

    2014-04-15

    Accurate expression for the momentum transfer cross section for the attractive Yukawa potential is proposed. This simple analytic expression agrees with the numerical results better than to within ±2% in the regime relevant for ion-particle collisions in complex (dusty) plasmas.

  18. C+C Fusion Cross Sections Measurements for Nuclear Astrophysics

    NASA Astrophysics Data System (ADS)

    Almaraz-Calderon, S.; Carnelli, P. F. F.; Rehm, K. E.; Albers, M.; Alcorta, M.; Bertone, P. F.; Digiovine, B.; Esbensen, H.; Fernandez Niello, J. O.; Henderson, D.; Jiang, C. L.; Lai, J.; Marley, S. T.; Nusair, O.; Palchan-Hazan, T.; Pardo, R. C.; Paul, M.; Ugalde, C.

    2015-06-01

    Total fusion cross section of carbon isotopes were obtained using the newly developed MUSIC detector. MUSIC is a highly efficient, active target-detector system designed to measure fusion excitation functions with radioactive beams. The present measurements are relevant for understanding x-ray superbursts. The results of the first MUSIC campaign as well as the astrophysical implications are presented in this work.

  19. On the interweaving of partial cross sections of different parity

    NASA Technical Reports Server (NTRS)

    Devries, P. L.; George, T. F.

    1979-01-01

    Partial cross sections of definite parity, calculated for electronic-rotational energy transfer in the F +H2 collision system, interweave with increasing total angular momentum J. An explanation, in terms of diabatic curve crossings induced by the centrifugal potential in the body-fixed coordinate system, predicts the interweaving to occur only in systems having half-integer J.

  20. Commentary: Mediation Analysis, Causal Process, and Cross-Sectional Data

    ERIC Educational Resources Information Center

    Shrout, Patrick E.

    2011-01-01

    Maxwell, Cole, and Mitchell (2011) extended the work of Maxwell and Cole (2007), which raised important questions about whether mediation analyses based on cross-sectional data can shed light on longitudinal mediation process. The latest article considers longitudinal processes that can only be partially explained by an intervening variable, and…

  1. On total cross sections and slopes at superhigh energies

    NASA Technical Reports Server (NTRS)

    Yeremian, S. S.; Zhamkochian, V. M.

    1985-01-01

    Hadron-hadron and hadron-nucleus interactions are investigated in the framework of the Reggeon field theory with critical and supercritical pomerons and multiple scattering theory. A good agreement is obtained with experimental data on cross sections of proton-proton and proton-nucleus interactions at high energies.

  2. 44. Cross section of the Blacksmith Shop from Construction Drawing ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    44. Cross section of the Blacksmith Shop from Construction Drawing 2042-F-15, entitled Machine and Blacksmith Shop; Plan, Elevations, and Sections. (Original drawing, in the possession of Wyre Dick and Company, Livingston, New Jersey.) - Central Railroad of New Jersey, Engine Terminal, Jersey City, Hudson County, NJ

  3. 45. Cross Section through the Power House, from Construction Drawing ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    45. Cross Section through the Power House, from Construction Drawing 2042-F-23, entitled General Arrangement of Power Plant, Sections. (Original drawing, in the possession of Wyre Dick and Company, Livingston, New Jersey.) - Central Railroad of New Jersey, Engine Terminal, Jersey City, Hudson County, NJ

  4. Stellar neutron capture cross sections of the Lu isotopes

    SciTech Connect

    Wisshak, K.; Voss, F.; Kaeppeler, F.; Kazakov, L.

    2006-01-15

    The neutron capture cross sections of {sup 175}Lu and {sup 176}Lu have been measured in the energy range 3-225 keV at the Karlsruhe 3.7 MV Van de Graaff accelerator. Neutrons were produced via the {sup 7}Li(p,n){sup 7}Be reaction by bombarding metallic Li targets with a pulsed proton beam, and capture events were registered with the Karlsruhe 4{pi} barium fluoride detector. The cross sections were determined relative to the gold standard using isotopically enriched as well as natural lutetium oxide samples. Overall uncertainties of {approx}1% could be achieved in the final cross section ratios to the gold standard, about a factor of 5 smaller than in previous works. Maxwellian averaged neutron capture cross sections were calculated for thermal energies between kT = 8 and 100 keV. These values are systematically larger by {approx}7% than those reported in recent evaluations. These results are of crucial importance for the assessment of the s-process branchings at A 175/176.

  5. Neutrino Cross-Section Measurements at the Spallation Neutron Source

    SciTech Connect

    Stancu, Ion

    2008-02-21

    In this paper we discuss the proposal to build a neutrino facility at the recently-completed Spallation Neutron Source (SNS) at the Oak Ridge National Laboratory (ORNL). This facility can host an extensive, long-term program to study neutrino-nucleus cross-sections in the range of interest for nuclear astrophysics and nuclear theory.

  6. Photoionization cross sections and oscillator strengths of neutral cesium

    NASA Astrophysics Data System (ADS)

    Haq, S. U.; Nadeem, Ali; Nawaz, M.

    2012-11-01

    The absolute photoionization cross sections from the 6p 2P1/2 excited state of cesium at threshold and above the threshold region have been measured using the saturation absorption technique. The photoionization cross section at the ionization threshold is determined as 22.6±3.6 Mb, whereas in the region above threshold its value ranges from 22 to 20 Mb for photoelectron energies up to 0.1 eV. A comparison of the photoionization cross sections with earlier reported theoretical and experimental data have been presented and are in good agreement within the uncertainty. In addition, the oscillator strengths of the 6p 2P1/2→n d 2D3/2 (21≤n≤60) Rydberg transitions of cesium have been calibrated using the threshold value of the photoionization cross section. A complete picture of the oscillator strengths from the present work and previously reported data from n=5-60 is presented.

  7. Extracting cross sections and water levels of minor streams and ditches from LiDAR point data

    NASA Astrophysics Data System (ADS)

    Roelens, Jennifer; Dondeyne, Stefaan; Deckers, Jozef; Van Orshoven, Jos; Diels, Jan

    2016-04-01

    Quantitative data on the shape and dimensions of location-specific cross-sections is useful for water and floodplain management. In addition, information about the water level is often needed, for example to be used as a boundary condition in hydrological, hydraulic and groundwater models. To detect a water course, let alone the cross section of small streams, the spatial resolution of DEM's derived from LiDAR or other data sources is insufficient. This is not the case for high resolution LiDAR data clouds. An aerial LiDAR database encompassing on average 16 points per square meter is available for the entire Flanders region. LiDAR elevation point clouds and digital RGB aerial images were collected simultaneously. To extract the right points for determination of the water course's cross-section at a given location, a buffer zone is defined around a predefined cross-section. This is based on the assumption that the cross-section of a channel is invariable over a small distance (0.1-1m). The set of extracted and then projected points was subjected to curve fitting based on shape language modelling (SLM). Based on the modelled cross-sectional profile, characteristics like cross-sectional area, width and water level were extracted. Furthermore, normalized indices combining the RGB and intensity data were used to detect the presence of water and the different characteristics of the points close to the water level and close to the banks. The study area is located in the alluvial valley of the Dijle, 20 km east of Brussels. It is part of the nature reserve 'de Doode Bemde'. The area of the test site is 10.3 ha and contains a ditch network of approximately three km. The field data, collected during August 2015 with a real time kinematic (RTK) GPS, was used for validation. The measurement result contained 153 cross sections with all the bathymetry data under the water level. Validation showed that all of the cross-sections modelled with the LiDAR data had a positive mean

  8. Thermal neutron capture cross sections of the potassium isotopes

    NASA Astrophysics Data System (ADS)

    Firestone, R. B.; Krtička, M.; Révay, Zs.; Szentmiklosi, L.; Belgya, T.

    2013-02-01

    Precise thermal neutron capture γ-ray cross sections σγ for 39,40,41K were measured on a natural potassium target with the guided neutron beam at the Budapest Reactor. The cross sections were internally standardized using a stoichiometric KCl target with well-known 35Cl(n,γ) γ-ray cross sections [Révay and Molnár, Radiochimica ActaRAACAP0033-823010.1524/ract.91.6.361.20027 91, 361 (2003); Molnár, Révay, and Belgya, Nucl. Instrum. Meth. Phys. Res. BNIMBEU0168-583X10.1016/S0168-583X(03)01529-5 213, 32 (2004)]. These data were combined with γ-ray intensities from von Egidy [von Egidy, Daniel, Hungerford, Schmidt, Lieb, Krusche, Kerr, Barreau, Borner, Brissot , J. Phys. G. Nucl. Phys.JPHGBM0305-461610.1088/0305-4616/10/2/013 10, 221 (1984)] and Krusche [Krusche, Lieb, Ziegler, Daniel, von Egidy, Rascher, Barreau, Borner, and Warner, Nucl. Phys. ANUPABL0375-947410.1016/0375-9474(84)90506-2 417, 231 (1984); Krusche, Winter, Lieb, Hungerford, Schmidt, von Egidy, Scheerer, Kerr, and Borner, Nucl. Phys. ANUPABL0375-947410.1016/0375-9474(85)90429-4 439, 219 (1985)] to generate nearly complete capture γ-ray level schemes. Total radiative neutron cross sections were deduced from the total γ-ray cross section feeding the ground state, σ0=Σσγ(GS) after correction for unobserved statistical γ-ray feeding from levels near the neutron capture energy. The corrections were performed with Monte Carlo simulations of the potassium thermal neutron capture decay schemes using the computer code dicebox where the simulated populations of low-lying levels are normalized to the measured cross section depopulating those levels. Comparisons of the simulated and experimental level feeding intensities have led to proposed new spins and parities for selected levels in the potassium isotopes where direct reactions are not a significant contribution. We determined the total radiative neutron cross sections σ0(39K)=2.28±0.04 b, σ0(40K)=90±7 b, and σ0(41K)=1.62±0.03 b from the

  9. Absolute photoionization cross-section of the methyl radical.

    SciTech Connect

    Taatjes, C. A.; Osborn, D. L.; Selby, T.; Meloni, G.; Fan, H.; Pratt, S. T.; Chemical Sciences and Engineering Division; SNL

    2008-01-01

    The absolute photoionization cross-section of the methyl radical has been measured using two completely independent methods. The CH{sub 3} photoionization cross-section was determined relative to that of acetone and methyl vinyl ketone at photon energies of 10.2 and 11.0 eV by using a pulsed laser-photolysis/time-resolved synchrotron photoionization mass spectrometry method. The time-resolved depletion of the acetone or methyl vinyl ketone precursor and the production of methyl radicals following 193 nm photolysis are monitored simultaneously by using time-resolved synchrotron photoionization mass spectrometry. Comparison of the initial methyl signal with the decrease in precursor signal, in combination with previously measured absolute photoionization cross-sections of the precursors, yields the absolute photoionization cross-section of the methyl radical; {sigma}{sub CH}(10.2 eV) = (5.7 {+-} 0.9) x 10{sup -18} cm{sup 2} and {sigma}{sub CH{sub 3}}(11.0 eV) = (6.0 {+-} 2.0) x 10{sup -18} cm{sup 2}. The photoionization cross-section for vinyl radical determined by photolysis of methyl vinyl ketone is in good agreement with previous measurements. The methyl radical photoionization cross-section was also independently measured relative to that of the iodine atom by comparison of ionization signals from CH{sub 3} and I fragments following 266 nm photolysis of methyl iodide in a molecular-beam ion-imaging apparatus. These measurements gave a cross-section of (5.4 {+-} 2.0) x 10{sup -18} cm{sup 2} at 10.460 eV, (5.5 {+-} 2.0) x 10{sup -18} cm{sup 2} at 10.466 eV, and (4.9 {+-} 2.0) x 10{sup -18} cm{sup 2} at 10.471 eV. The measurements allow relative photoionization efficiency spectra of methyl radical to be placed on an absolute scale and will facilitate quantitative measurements of methyl concentrations by photoionization mass spectrometry.

  10. Froissart bound on inelastic cross section without unknown constants

    NASA Astrophysics Data System (ADS)

    Martin, André; Roy, S. M.

    2015-04-01

    Assuming that axiomatic local field theory results hold for hadron scattering, André Martin and S. M. Roy recently obtained absolute bounds on the D wave below threshold for pion-pion scattering and thereby determined the scale of the logarithm in the Froissart bound on total cross sections in terms of pion mass only. Previously, Martin proved a rigorous upper bound on the inelastic cross-section σinel which is one-fourth of the corresponding upper bound on σtot, and Wu, Martin, Roy and Singh improved the bound by adding the constraint of a given σtot. Here we use unitarity and analyticity to determine, without any high-energy approximation, upper bounds on energy-averaged inelastic cross sections in terms of low-energy data in the crossed channel. These are Froissart-type bounds without any unknown coefficient or unknown scale factors and can be tested experimentally. Alternatively, their asymptotic forms, together with the Martin-Roy absolute bounds on pion-pion D waves below threshold, yield absolute bounds on energy-averaged inelastic cross sections. For example, for π0π0 scattering, defining σinel=σtot-(σπ0π0→π0π0+σπ0π0→π+π-) , we show that for c.m. energy √{s }→∞, σ¯ inel(s ,∞)≡s ∫s∞d s'σinel(s')/s'2≤(π /4 )(mπ)-2[ln (s /s1)+(1 /2 )ln ln (s /s1)+1 ]2 where 1 /s1=34 π √{2 π }mπ-2 . This bound is asymptotically one-fourth of the corresponding Martin-Roy bound on the total cross section, and the scale factor s1 is one-fourth of the scale factor in the total cross section bound. The average over the interval (s,2s) of the inelastic π0π0 cross section has a bound of the same form with 1 /s1 replaced by 1 /s2=2 /s1.

  11. Lung function and airway diseases.

    PubMed

    Weiss, Scott T

    2010-01-01

    Two studies report genome-wide association studies for lung function, using cross-sectional spirometric measurements in healthy individuals. They identify six genetic loci newly associated to natural variation in lung function, which may have implications for the related airway diseases of asthma and chronic obstructive pulmonary disease. PMID:20037613

  12. Plume rise from a chimney with an elongated exit cross section

    NASA Astrophysics Data System (ADS)

    Seifert, A.; Shemer, L.

    The effect of using a nozzle with an elongated exit cross section as a passive device for increasing jet penetration into cross flow was studied experimentally in a wind tunnel. It was found that the smoke plume dispersion and jet penetration are governed not only by the ratio of flow velocities in the pipe and in the cross flour, but also by the shape of the exit cross section and its orientation with respect to the cross flow. An elongated exit cross section may be particularly effective whenever only a narrow wedge of wind directions leads to air pollution of populated areas. It was found that when such a nozzle is oriented along the wind direction, the chimney effective height is increased as compared to a circular exit cross section, in spite of the fact that the velocity ratio in our experiments was higher for the circular exit. Possible physical reasons for the advantage of the elongated over the circular section shape at the exit are discussed.

  13. Scaled plane-wave Born cross sections for atoms and molecules

    NASA Astrophysics Data System (ADS)

    Tanaka, H.; Brunger, M. J.; Campbell, L.; Kato, H.; Hoshino, M.; Rau, A. R. P.

    2016-04-01

    Integral cross sections for optically allowed electronic-state excitations of atoms and molecules by electron impact, by applying scaled plane-wave Born models, are reviewed. Over 40 years ago, Inokuti presented an influential review of charged-particle scattering, based on the theory pioneered by Bethe forty years earlier, which emphasized the importance of reliable cross-section data from low eV energies to high keV energies that are needed in many areas of radiation science with applications to astronomy, plasmas, and medicine. Yet, with a couple of possible exceptions, most computational methods in electron-atom scattering do not, in general, overlap each other's validity range in the region from threshold up to 300 eV and, in particular, in the intermediate region from 30 to 300 eV. This is even more so for electron-molecule scattering. In fact this entire energy range is of great importance and, to bridge the gap between the two regions of low and high energy, scaled plane-wave Born models were developed to provide reliable, comprehensive, and absolute integral cross sections, first for ionization by Kim and Rudd and then extended to optically allowed electronic-state excitation by Kim. These and other scaling models in a broad, general application to electron scattering from atoms and molecules, their theoretical basis, and their results for cross sections along with comparison to experimental measurements are reviewed. Where possible, these data are also compared to results from other computational approaches.

  14. An X-Ray Analysis Database of Photoionization Cross Sections Including Variable Ionization

    NASA Technical Reports Server (NTRS)

    Wang, Ping; Cohen, David H.; MacFarlane, Joseph J.; Cassinelli, Joseph P.

    1997-01-01

    Results of research efforts in the following areas are discussed: review of the major theoretical and experimental data of subshell photoionization cross sections and ionization edges of atomic ions to assess the accuracy of the data, and to compile the most reliable of these data in our own database; detailed atomic physics calculations to complement the database for all ions of 17 cosmically abundant elements; reconciling the data from various sources and our own calculations; and fitting cross sections with functional approximations and incorporating these functions into a compact computer code.Also, efforts included adapting an ionization equilibrium code, tabulating results, and incorporating them into the overall program and testing the code (both ionization equilibrium and opacity codes) with existing observational data. The background and scientific applications of this work are discussed. Atomic physics cross section models and calculations are described. Calculation results are compared with available experimental data and other theoretical data. The functional approximations used for fitting cross sections are outlined and applications of the database are discussed.

  15. Cross-section Trichometry: A Clinical Tool for Assessing the Progression and Treatment Response of Alopecia

    PubMed Central

    Wikramanayake, Tongyu Cao; Mauro, Lucia M; Tabas, Irene A; Chen, Anne L; Llanes, Isabel C; Jimenez, Joaquin J

    2012-01-01

    Background: To properly assess the progression and treatment response of alopecia, one must measure the changes in hair mass, which is influenced by both the density and diameter of hair. Unfortunately, a convenient device for hair mass evaluation had not been available to dermatologists until the recent introduction of the cross-section trichometer, which directly measures the cross-sectional area of an isolated bundle of hair. Objective: We sought to evaluate the accuracy and sensitivity of the HairCheck® device, a commercial product derived from the original cross-section trichometer. Materials and Methods: Bundles of surgical silk and human hair were used to evaluate the ability of the HairCheck® device to detect and measure small changes in the number and diameter of strands, and bundle weight. Results: Strong correlations were observed between the bundle's cross-sectional area, displayed as the numeric Hair Mass Index (HMI), the number of strands, the silk/hair diameter, and the bundle dry weight. Conclusion: HMI strongly correlated with the number and diameter of silk/hair, and the weight of the bundle, suggesting that it can serve as a valid indicator of hair mass. We have given the name cross-section trichometry (CST) to the methodology of obtaining the HMI using the HairCheck® system. CST is a simple modality for the quantification of hair mass, and may be used as a convenient and useful tool to clinically assess changes in hair mass caused by thinning, shedding, breakage, or growth in males and females with progressive alopecia or those receiving alopecia treatment. PMID:23766610

  16. Stellar neutron capture cross sections of the Nd isotopes

    SciTech Connect

    Wisshak, K.; Voss, F.; Kaeppeler, F.; Kazakov, L.; Reffo, G.

    1998-01-01

    The neutron capture cross sections of {sup 142}Nd, {sup 143}Nd, {sup 144}Nd, {sup 145}Nd, {sup 146}Nd, and {sup 148}Nd have been measured in the energy range from 3 to 225 keV at the Karlsruhe 3.75 MV Van de Graaff accelerator. Neutrons were produced via the {sup 7}Li(p,n){sup 7}Be reaction by bombarding metallic Li targets with a pulsed proton beam. Capture events were registered with the Karlsruhe 4{pi} Barium Fluoride Detector. The cross sections were determined relative to the gold standard. The experiment was difficult due to the small cross sections of the even isotopes at or near the magic neutron number N=82, and also since the isotopic enrichment of some samples was comparably low. The necessary corrections for capture of scattered neutrons and for isotopic impurities could be determined reliably thanks to the high efficiency and the spectroscopic quality of the BaF{sub 2} detector, resulting in a consistent set of (n,{gamma}) cross sections for the six stable neodymium isotopes involved in the s process with typical uncertainties of 1.5{endash}2{percent}. From these data, Maxwellian averaged cross sections were calculated between kT=10 and 100 keV. The astrophysical implications of these results were investigated in an s-process analysis, which deals with the role of the s-only isotope {sup 142}Nd for the N{sub s}{l_angle}{sigma}{r_angle} systematics near the magic neutron number N=82, the decomposition of the Nd abundances into the respective r-, s-, and p-process components, and the interpretation of isotopic anomalies in meteoritic material. {copyright} {ital 1998} {ital The American Physical Society}

  17. Electron impact ionisation cross sections of iron hydrogen clusters

    NASA Astrophysics Data System (ADS)

    Huber, Stefan E.; Sukuba, Ivan; Urban, Jan; Limtrakul, Jumras; Probst, Michael

    2016-09-01

    We computed electron impact ionisation cross sections (EICSs) of iron hydrogen clusters, FeH n with n = 1,2, ...,10, from the ionisation threshold to 10 keV using the Deutsch-Märk (DM) and the binary-encounter-Bethe (BEB) formalisms. The maxima of the cross sections for the iron hydrogen clusters range from 6.13 × 10-16 cm2 at 60 eV to 8.76 × 10-16 cm2 at 76 eV for BEB-AE (BEB method based on quantum-chemical data from all-electron basis sets) calculations, from 4.15 × 10-16 cm2 at 77 eV to 7.61 × 10-16 cm2 at 80 eV for BEB-ECP (BEB method based on quantum-chemical data from effective-core potentials for inner-core electrons) calculations and from 2.49 × 10-16 cm2 at 43.5 eV to 7.04 × 10-16 cm2 at 51 eV for the DM method. Cross sections calculated via the BEB method are substantially higher than the ones obtained via the DM method, up to a factor of about two for FeH and FeH2. The formation of Fe-H bonds depopulates the iron 4 s orbital, causing significantly lower cross sections for the small iron hydrides compared to atomic iron. Both the DM and BEB cross sections can be fitted perfectly against a simple expression used in modelling and simulation codes in the framework of nuclear fusion research. The energetics of the iron hydrogen clusters change substantially when exact exchange is present in the density functional, while the cluster geometries do not depend on this choice.

  18. Absolute doubly differential bremsstrahlung cross sections from rare gas atoms

    NASA Astrophysics Data System (ADS)

    Portillo, Salvador

    The absolute doubly differential bremsstrahlung cross section has been measured for 28 and 50 keV electrons incident on the rare gases Xe, Kr, Ar and Ne. The cross sections are differential with respect to energy and photon emission. A SiLi solid state detector measured data at 90° with respect to the beam line. A thorough analysis of the experimental systematic error yielded a high degree of confidence in the experimental data. The absolute bremsstrahlung doubly differential cross sections provided for a rigorous test of the normal bremsstrahlung theory, tabulated by Kissel, Quarles and Pratt1 (KQP) and of the SA theory2 that includes the contribution from polarization bremsstrahlung. To test the theories a comparison of the overall magnitude of the cross section as well as comparison of the photon energy dependence was carried out. The KQP theoretical values underestimated the magnitude of the cross section for all targets and for both energies. The SA values were in excellent agreement with the 28 keV data. For the 50keV data the fit was also very good. However, there were energy regions where there was a small discrepancy between the theory and the data. This suggests that the Polarization Bremsstrahlung (PB) mechanism does contribute to the overall spectrum and is detectable in this parameter space. 1Kissel, L., Quarles, C. A., Pratt, R. H., Atom. Data Nucl. Data Tables 28, 381 (1983). 2Avdonina N. B., Pratt, R. H., J. Phys. B: At. Mol. Opt. Phys. 32 4261 (1999).

  19. Total electron scattering and electronic state excitations cross sections for O2, CO, and CH4

    NASA Technical Reports Server (NTRS)

    Kanik, I.; Trajmar, S.; Nickel, J. C.

    1993-01-01

    Available electron collision cross section data concerning total and elastic scattering, vibrational excitation, and ionization for O2, CO, and CH4 have been critically reviewed, and a set of cross sections for modeling of planetary atmospheric behavior is recommended. Utilizing these recommended cross sections, we derived total electronic state excitation cross sections and upper limits for dissociation cross sections, which in the case of CH4 should very closely equal the actual dissociation cross section.

  20. Calculation of photoionization cross section near auto-ionizing lines and magnesium photoionization cross section near threshold

    NASA Technical Reports Server (NTRS)

    Moore, E. N.; Altick, P. L.

    1972-01-01

    The research performed is briefly reviewed. A simple method was developed for the calculation of continuum states of atoms when autoionization is present. The method was employed to give the first theoretical cross section for beryllium and magnesium; the results indicate that the values used previously at threshold were sometimes seriously in error. These threshold values have potential applications in astrophysical abundance estimates.

  1. 70 Group Neutron Fast Reactor Cross Section Set and 25 Group Neutron Fast Reactor Cross Section Set.

    1984-10-29

    Version 00 These multigroup cross sections are used in fast reactor calculations. The benchmark calculations for the 23 fast critical assemblies used in the benchmark tests of JFS-2 were performed with one-dimensional diffusion theory by using the JFS-3-J2 set.

  2. Gonorrhoea in inner London: results of a cross sectional study.

    PubMed Central

    Low, N.; Daker-White, G.; Barlow, D.; Pozniak, A. L.

    1997-01-01

    OBJECTIVES: To estimate population based incidence rates of gonorrhoea in an inner London area and examine relations with age, ethnic group, and socioeconomic deprivation. DESIGN: Cross sectional study. SETTING: 11 departments of genitourinary medicine in south and central London. SUBJECTS: 1978 first episodes of gonorrhoea diagnosed in 1994 and 1995 in residents of 73 electoral wards in the boroughs of Lambeth, Southwark, and Lewisham who attended any of the departments of genitourinary medicine. MAIN OUTCOME MEASURES: Yearly age, sex, and ethnic group specific rates of gonorrhoea per 100,000 population aged 15-59 years; rate ratios for the effects of age and ethnic group on gonorrhoea rates in women and men before and after adjustment for confounding factors. RESULTS: Overall incidence rates of gonorrhoea in residents of Lambeth, Southwark, and Lewisham were 138.3 cases yearly per 100,000 women and 291.9 cases yearly per 100,000 men aged 15-59 years. At all ages gonorrhoea rates were higher in non-white minority ethnic groups. Rate ratios for the effect of age adjusted for ethnic group and underprivilege were 15.2 (95% confidence interval 11.6 to 19.7) for women and 2.0 (1.7 to 2.5) for men aged 15-19 years compared with those over 30. After deprivation score and age were taken into account, women from black minority groups were 10.5 (8.6 to 12.8) times as likely and men 11.0 (9.7 to 12.6) times as likely as white people to experience gonorrhoea. CONCLUSIONS: Gonorrhoea rates in Lambeth, Southwark, and Lewisham in 1994-5 were six to seven times higher than for England and Wales one year earlier. The presentation of national trends thus hides the disproportionate contribution of ongoing endemic transmission in the study area. Teenage women and young adult men, particularly those from black minority ethnic groups, are the most heavily affected, even when socioeconomic underprivilege is taken into account. There is urgent need for resources for culturally

  3. Detection and interpretation of ocean roughness variations across the Gulf Stream inferred from radar cross section observations

    NASA Technical Reports Server (NTRS)

    Weissman, D. E.; Thompson, T. W.

    1977-01-01

    Radar cross section data shows that the Gulf Stream has a higher cross section per unit area (interpreted here as a greater roughness) than the water on the continental shelf. A steep gradient in cross section was often seen at the expected location of the western boundary. There were also longer-scale (10-20 km) gradual fluctuations within the stream of significant magnitude. These roughness variations are correlated with the surface shear stress that the local wind imposes on the sea. Using the available surface-truth information concerning the wind speed and direction, an assumed Gulf Stream velocity profile, and high-resolution ocean-surface temperature data obtained by the VHRR onboard a NOAA-NESS polar-orbiting satellite, the present study demonstrates that the computed surface stress variation bears a striking resemblance to the measured radar cross-section variations.

  4. Automated continuous quantitative measurement of proximal airways on dynamic ventilation CT: initial experience using an ex vivo porcine lung phantom

    PubMed Central

    Yamashiro, Tsuneo; Tsubakimoto, Maho; Nagatani, Yukihiro; Moriya, Hiroshi; Sakuma, Kotaro; Tsukagoshi, Shinsuke; Inokawa, Hiroyasu; Kimoto, Tatsuya; Teramoto, Ryuichi; Murayama, Sadayuki

    2015-01-01

    Background The purpose of this study was to evaluate the feasibility of continuous quantitative measurement of the proximal airways, using dynamic ventilation computed tomography (CT) and our research software. Methods A porcine lung that was removed during meat processing was ventilated inside a chest phantom by a negative pressure cylinder (eight times per minute). This chest phantom with imitated respiratory movement was scanned by a 320-row area-detector CT scanner for approximately 9 seconds as dynamic ventilatory scanning. Obtained volume data were reconstructed every 0.35 seconds (total 8.4 seconds with 24 frames) as three-dimensional images and stored in our research software. The software automatically traced a designated airway point in all frames and measured the cross-sectional luminal area and wall area percent (WA%). The cross-sectional luminal area and WA% of the trachea and right main bronchus (RMB) were measured for this study. Two radiologists evaluated the traceability of all measurable airway points of the trachea and RMB using a three-point scale. Results It was judged that the software satisfactorily traced airway points throughout the dynamic ventilation CT (mean score, 2.64 at the trachea and 2.84 at the RMB). From the maximum inspiratory frame to the maximum expiratory frame, the cross-sectional luminal area of the trachea decreased 17.7% and that of the RMB 29.0%, whereas the WA% of the trachea increased 6.6% and that of the RMB 11.1%. Conclusion It is feasible to measure airway dimensions automatically at designated points on dynamic ventilation CT using research software. This technique can be applied to various airway and obstructive diseases. PMID:26445535

  5. Absolute X-ray emission cross section measurements of Fe K transitions

    NASA Astrophysics Data System (ADS)

    Hell, Natalie; Brown, Gregory V.; Beiersdorfer, Peter; Boyce, Kevin R.; Grinberg, Victoria; Kelley, Richard L.; Kilbourne, Caroline; Leutenegger, Maurice A.; Porter, Frederick Scott; Wilms, Jörn

    2016-06-01

    We have measured the absolute X-ray emission cross sections of K-shell transitions in highly charged L- and K-shell Fe ions using the LLNL EBIT-I electron beam ion trap and the NASA GSFC EBIT Calorimeter Spectrometer (ECS). The cross sections are determined by using the ECS to simultaneously record the spectrum of the bound-bound K-shell transitions and the emission from radiative recombination from trapped Fe ions. The measured spectrum is then brought to an absolute scale by normalizing the measured flux in the radiative recombination features to their theoretical cross sections, which are well known. Once the spectrum is brought to an absolute scale, the cross sections of the K-shell transitions are determined. These measurements are made possible by the ECS, which consists of a 32 channel array, with 14 channels optimized for detecting high energy photons (hν > 10 keV) and 18 channels optimized for detecting low energy photons (hν < 10 keV). The ECS has a large collection area, relatively high energy resolution, and a large bandpass; all properties necessary for this measurement technique to be successful. These data will be used to benchmark cross sections in the atomic reference data bases underlying the plasma modeling codes used to analyze astrophysical spectra, especially those measured by the Soft X-ray Spectrometer calorimeter instrument recently launched on the Hitomi X-ray Observatory.This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344, and supported by NASA grants to LLNL and NASA/GSFC and by ESA under contract No. 4000114313/15/NL/CB.

  6. Neutron Capture Cross Sections of 236U and 234U

    NASA Astrophysics Data System (ADS)

    Rundberg, R. S.; Bredeweg, T. A.; Bond, E. M.; Haight, R. C.; Hunt, L. F.; Kronenberg, A.; O'Donnell, J. M.; Schwantes, J. M.; Ullmann, J. L.; Vieira, D. J.; Wilhelmy, J. B.; Wouters, J. M.

    2006-03-01

    Accurate neutron capture cross sections of the actinide elements at neutron energies up to 1 MeV are needed to better interpret archived nuclear test data, for post-detonation nuclear attribution, and the Advanced Fuel Cycle Initiative. The Detector for Advance Neutron Capture Experiments, DANCE, has unique capabilities that allow the differentiation of capture gamma rays from fission gamma rays and background gamma rays from scattered neutrons captured by barium isotopes in the barium fluoride scintillators. The DANCE array has a high granularity, 160 scintillators, high efficiency, and nearly 4-π solid angle. Through the use of cuts in cluster multiplicity and calorimetric energy the capture gamma-rays are differentiated from other sources of gamma rays. The preliminary results for the capture cross sections of 236U are in agreement with the ENDF/B-VI evaluation. The preliminary results for 234U lower are than ENDF/B-VI evaluation and are closer to older evaluations.

  7. Fast-neutron scattering cross sections of elemental silver

    SciTech Connect

    Smith, A.B.; Guenther, P.T.

    1982-05-01

    Differential neutron elastic- and inelastic-scattering cross sections of elemental silver are measured from 1.5 to 4.0 MeV at intervals of less than or equal to 200 keV and at 10 to 20 scattering angles distributed between 20 and 160/sup 0/. Inelastically-scattered neutron groups are observed corresponding to the excitation of levels at; 328 +- 13, 419 +- 50, 748 +- 25, 908 +- 26, 1150 +- 38, 1286 +- 25, 1507 +- 20, 1623 +- 30, 1835 +- 20 and 1944 +- 26 keV. The experimental results are used to derive an optical-statistical model that provides a good description of the observed cross sections. The measured values are compared with corresponding quantities given in ENDF/B-V.

  8. Turbulent combustion flow through variable cross section channel

    SciTech Connect

    Rogov, B.V.; Sokolova, I.A.

    1999-07-01

    The object of this study is to develop a new evolutionary numerical method for solving direct task of Laval nozzle, which provides non-iterative calculations of chemical reacting turbulent flows with detailed kinetic chemistry. The numerical scheme of fourth order along the normal coordinate and second order along the streamwise one is derived for calculation of difference-differential equations of the second order and the first order. Marching method provides the possibility of computing field flow in subsonic section of nozzle and near an expansion. Critical mass consumption is calculated with controlled accuracy. After critical cross section of nozzle a combined marching method with global iterations over axial pressure (only) makes it possible to overcome ill posedness of mixed supersonic flow and calculate the whole flow field near and after critical cross section. Numerical results are demonstrated on turbulent burning hydrogen-oxygen flow through Laval nozzle with curvature of wall K{sub w} = 0.5.

  9. Evolving roles of cross-sectional imaging in Crohn's disease.

    PubMed

    Magarotto, Andrea; Orlando, Stefania; Coletta, Marina; Conte, Dario; Fraquelli, Mirella; Caprioli, Flavio

    2016-09-01

    The implementation of cross-sectional imaging techniques for the clinical management of Crohn's disease patients has steadily grown over the recent years, thanks to a series of technological advances, including the evolution of contrast media for magnetic resonance, computed tomography and bowel ultrasound. This has resulted in a continuous improvement of diagnostic accuracy and capability to detect Crohn's disease-related complications. Additionally, a progressive widening of indications for cross-sectional imaging in Crohn's disease has been put forward, thus leading to hypothesize that in the near future imaging techniques can increasingly complement endoscopy in most clinical settings, including the grading of disease activity and the assessment of mucosal healing or Crohn's disease post-surgical recurrence.

  10. A dissociative electron attachment cross-section estimator

    NASA Astrophysics Data System (ADS)

    Munro, James J.; Harrison, Stephen; Fujimoto, Milton M.; Tennyson, Jonathan

    2012-11-01

    Dissociative electron attachment (DEA) is the major process where molecules are destroyed in low-energy plasmas. DEA cross sections are therefore important for a whole variety of applications but are both hard to measure or compute accurately. A method for estimating DEA cross sections based a simple resonance plus survival model is presented. Test results are presented for DEA of molecular oxygen and molecular chlorine, for which experimental measurements are available for comparison, and SiBr and SiBr2, for which no previous data is available. The estimator has been implemented as part of Quantemol-N expert system which uses the R-matrix method to predict resonance positions and widths.

  11. Experimental validation of lead cross sections for scale and MCNP

    SciTech Connect

    Henrikson, D.J.

    1995-12-01

    Moving spent nuclear fuel between facilities often requires the use of lead-shielded casks. Criticality safety that is based upon calculations requires experimental validation of the fuel matrix and lead cross section libraries. A series of critical experiments using a high-enriched uranium-aluminum fuel element with a variety of reflectors, including lead, has been identified. Twenty-one configurations were evaluated in this study. The fuel element was modelled for KENO V.a and MCNP 4a using various cross section sets. The experiments addressed in this report can be used to validate lead-reflected calculations. Factors influencing calculated k{sub eff} which require further study include diameters of styrofoam inserts and homogenization.

  12. Accurate Development of Thermal Neutron Scattering Cross Section Libraries

    SciTech Connect

    Hawari, Ayman; Dunn, Michael

    2014-06-10

    The objective of this project is to develop a holistic (fundamental and accurate) approach for generating thermal neutron scattering cross section libraries for a collection of important enutron moderators and reflectors. The primary components of this approach are the physcial accuracy and completeness of the generated data libraries. Consequently, for the first time, thermal neutron scattering cross section data libraries will be generated that are based on accurate theoretical models, that are carefully benchmarked against experimental and computational data, and that contain complete covariance information that can be used in propagating the data uncertainties through the various components of the nuclear design and execution process. To achieve this objective, computational and experimental investigations will be performed on a carefully selected subset of materials that play a key role in all stages of the nuclear fuel cycle.

  13. NIFFTE Time Projection Chamber for Fission Cross Section Measurements

    NASA Astrophysics Data System (ADS)

    Castillo, Ryan; Neutron Induced Fission Fragment Tracking Experiment Collaboration

    2011-10-01

    In order to design safer and more efficient Generation IV nuclear reactors, more accurate knowledge of fission cross sections is needed. The goal of the Time Projection Chamber (TPC) used by the Neutron Induced Fission Fragment Tracking Experiment (NIFFTE) collaboration is to measure the cross sections of several fissile materials to within 1% uncertainty. The ability of the TPC to produce 3D ``pictures'' of charged particle trajectories will eliminate unwanted alpha particles in the data. Another important source of error is the normalization of data the U-235 standard. NIFFTE will use the H(n,n)H reaction instead, which is known to better than 0.2%. The run control and monitoring system will eventually allow for nearly complete automation and off-site monitoring of the experiment. This presentation will cover the need for precision measurements and an overview of the experiment. This work was supported by the U.S. Department of Energy Division of Energy Research.

  14. Neutron Capture Cross Sections of 236U and 234U

    SciTech Connect

    Rundberg, R. S.; Bredeweg, T. A.; Bond, E. M.; Haight, R. C.; Hunt, L. F.; O'Donnell, J. M.; Schwantes, J. M.; Ullmann, J. L.; Vieira, D. J.; Wilhelmy, J. B.; Wouters, J. M.; Kronenberg, A.

    2006-03-13

    Accurate neutron capture cross sections of the actinide elements at neutron energies up to 1 MeV are needed to better interpret archived nuclear test data, for post-detonation nuclear attribution, and the Advanced Fuel Cycle Initiative. The Detector for Advance Neutron Capture Experiments, DANCE, has unique capabilities that allow the differentiation of capture gamma rays from fission gamma rays and background gamma rays from scattered neutrons captured by barium isotopes in the barium fluoride scintillators. The DANCE array has a high granularity, 160 scintillators, high efficiency, and nearly 4-{pi} solid angle. Through the use of cuts in cluster multiplicity and calorimetric energy the capture gamma-rays are differentiated from other sources of gamma rays. The preliminary results for the capture cross sections of 236U are in agreement with the ENDF/B-VI evaluation. The preliminary results for 234U lower are than ENDF/B-VI evaluation and are closer to older evaluations.

  15. Absolute photoionization cross sections of the ions Ca+ Ni+

    NASA Astrophysics Data System (ADS)

    Hansen, J. E.; Kjeldsen, H.; Folkmann, F.; Martins, M.; West, J. B.

    2007-01-01

    Absolute measurements of the photoionization cross sections of the singly charged ions in the sequence Ca to Ni are presented, focussing on the 3p → 3d resonance region. Major differences are found in both spectral structure and cross section as the 3d shell is filled progressively. The behaviour of the total oscillator strength is studied as well as its relation to the collapse of the 3d orbital. The 3p53d 1P term is found to have an influence on the spectra even when further 3d electrons are added and this dependence combined with the effect of Hund's rule leads to a considerable simplification in the structure of the absorption spectra before the half-filled 3d shell, while from the half-filled 3d shell Hund's rule is the main simplifying effect.

  16. Vortex breakdown in closed containers with polygonal cross sections

    SciTech Connect

    Naumov, I. V. Dvoynishnikov, S. V.; Kabardin, I. K.; Tsoy, M. A.

    2015-12-15

    The vortex breakdown bubble in the confined flow generated by a rotating lid in closed containers with polygonal cross sections was analysed both experimentally and numerically for the height/radius aspect ratio equal to 2. The stagnation point locations of the breakdown bubble emergence and the corresponding Reynolds number were determined experimentally and in addition computed numerically by STAR-CCM+ CFD software for square, pentagonal, hexagonal, and octagonal cross section configurations. The flow pattern and the velocity were observed and measured by combining the seeding particle visualization and the temporal accuracy of laser Doppler anemometry. The vortex breakdown size and position on the container axis were determined for Reynolds numbers, ranging from 1450 to 2400. The obtained results were compared with the flow structure in the closed container of cubical and cylindrical configurations. It is shown that the measured evolution of steady vortex breakdown is in close agreement with the numerical results.

  17. Developing Scientific Reasoning Through Drawing Cross-Sections

    NASA Astrophysics Data System (ADS)

    Hannula, K. A.

    2012-12-01

    Cross-sections and 3D models of subsurface geology are typically based on incomplete information (whether surface geologic mapping, well logs, or geophysical data). Creating and evaluating those models requires spatial and quantitative thinking skills (including penetrative thinking, understanding of horizontality, mental rotation and animation, and scaling). However, evaluating the reasonableness of a cross-section or 3D structural model also requires consideration of multiple possible geometries and geologic histories. Teaching students to create good models requires application of the scientific methods of the geosciences (such as evaluation of multiple hypotheses and combining evidence from multiple techniques). Teaching these critical thinking skills, especially combined with teaching spatial thinking skills, is challenging. My Structural Geology and Advanced Structural Geology courses have taken two different approaches to developing both the abilities to visualize and to test multiple models. In the final project in Structural Geology (a 3rd year course with a pre-requisite sophomore mapping course), students create a viable cross-section across part of the Wyoming thrust belt by hand, based on a published 1:62,500 geologic map. The cross-section must meet a number of geometric criteria (such as the template constraint), but is not required to balance. Each student tries many potential geometries while trying to find a viable solution. In most cases, the students don't visualize the implications of the geometries that they try, but have to draw them and then erase their work if it does not meet the criteria for validity. The Advanced Structural Geology course used Midland Valley's Move suite to test the cross-sections that they made in Structural Geology, mostly using the flexural slip unfolding algorithm and testing whether the resulting line lengths balanced. In both exercises, students seemed more confident in the quality of their cross-sections when the

  18. Cross-Section Measurements with the Radioactive Isotope Accelerator (ria)

    NASA Astrophysics Data System (ADS)

    Stoyer, M. A.; Moody, K. J.; Wild, J. F.; Patin, J. B.; Shaughnessy, D. A.; Stoyer, N. J.; Harris, L. J.

    2003-10-01

    RIA will produce beams of exotic nuclei of unprecedented luminosity. Preliminary studies of the feasibility of measuring cross-sections of interest to the science based stockpile stewardship (SBSS) program will be presented, and several experimental techniques will be discussed. Cross-section modeling attempts for the A = 95 mass region will be shown. In addition, several radioactive isotopes could be collected for target production or medical isotope purposes while the main in-beam experiments are running. The inclusion of a broad range mass analyzer (BRAMA) capability at RIA will enable more effective utilization of the facility, enabling the performance of multiple experiments at the same time. This option will be briefly discussed.

  19. Vortex breakdown in closed containers with polygonal cross sections

    NASA Astrophysics Data System (ADS)

    Naumov, I. V.; Dvoynishnikov, S. V.; Kabardin, I. K.; Tsoy, M. A.

    2015-12-01

    The vortex breakdown bubble in the confined flow generated by a rotating lid in closed containers with polygonal cross sections was analysed both experimentally and numerically for the height/radius aspect ratio equal to 2. The stagnation point locations of the breakdown bubble emergence and the corresponding Reynolds number were determined experimentally and in addition computed numerically by STAR-CCM+ CFD software for square, pentagonal, hexagonal, and octagonal cross section configurations. The flow pattern and the velocity were observed and measured by combining the seeding particle visualization and the temporal accuracy of laser Doppler anemometry. The vortex breakdown size and position on the container axis were determined for Reynolds numbers, ranging from 1450 to 2400. The obtained results were compared with the flow structure in the closed container of cubical and cylindrical configurations. It is shown that the measured evolution of steady vortex breakdown is in close agreement with the numerical results.

  20. Cross-Section Measurements with the Radioactive Isotope Accelerator (RIA)

    SciTech Connect

    Stoyer, M A; Moody, K J; Wild, J F; Patin, J B; Shaughnessy, D A; Stoyer, N J; Harris, L J

    2002-11-19

    RIA will produce beams of exotic nuclei of unprecedented luminosity. Preliminary studies of the feasibility of measuring cross-sections of interest to the science based stockpile stewardship (SBSS) program will be presented, and several experimental techniques will be discussed. Cross-section modeling attempts for the A = 95 mass region will be shown. In addition, several radioactive isotopes could be collected for target production or medical isotope purposes while the main in-beam experiments are running. The inclusion of a broad range mass analyzer (BRAMA) capability at RIA will enable more effective utilization of the facility, enabling the performance of multiple experiments at the same time. This option will be briefly discussed.

  1. Improved activation cross sections for vanadium and titanium

    SciTech Connect

    Muir, D.W.; Arthur, E.D.

    1983-01-01

    Vanadium alloys such as V-20Ti and V-Cr-Ti are attractive candidates for use as structural materials in fusion-reactor blankets. The virtual absence of long-lived activation products in these alloys suggest the possibility of reprocessing on an intermediate time scale. We have employed the modern Hauser-Feshbach nuclear-model code GNASH to calculate cross sections for neutron-activation reactions in /sup 50/V and /sup 51/V, to allow a more accurate assessment of induced radioactivity in vanadium alloys. In addition, cross sections are calculated for the reactions /sup 46/Ti(n,2n) and /sup 45/Ti(n,2n) in order to estimate the production of /sup 44/Ti, a 1.2-MeV gamma-ray source with a half-life of 47 years.

  2. Elastic total cross-sections in an RSIIp scenario

    NASA Astrophysics Data System (ADS)

    Arceo, R.; Pedraza, Omar; López, L. A.; Valencia-Palomo, L.; González-Espinosa, E.; Leon-Soto, G.; Kurtz, Stan

    2016-10-01

    The total elastic nucleon-nucleus cross-section is calculated at energies up to 600 MeV for the elements 12C, 208Pb, 16O, 9Be, 4He, 2H, 238U and 27Al using a finite electromagnetic potential, which is obtained considering a Randall-Sundrum II scenario modified by the inclusion of p compact extra dimensions. The length scale bound is set in the potential to compare with known experimental data.

  3. Measurements of cross sections relevant to. gamma. -ray line astronomy

    SciTech Connect

    Lesko, K.T.; Norman, E.B.; Larimer, R.M.; Crane, S.G.

    1986-06-01

    Gamma-ray production cross sections have been measured for the ..gamma..-ray lines which are mostly strongly excited in the proton bombardment of C, O, Mg, Si, and Fe targets of natural isotopic composition. High resolution germanium detectors were used to collect ..gamma..-ray spectra at proton bombarding energies of 20, 30, 33, 40 and 50 MeV. 6 refs., 6 figs.

  4. W and Z cross sections at the Tevatron

    SciTech Connect

    T. Dorigo

    2003-07-01

    The CDF and D0 experiments at the Tevatron have used p{bar p} collisions at {radical}s = 1.96 TeV to measure the cross section of W and Z boson production using several leptonic final states. An indirect measurement of the total W width has been extracted, and the lepton charge asymmetry in Drell-Yan production has been studied up to invariant masses of 600 GeV/c{sup 2}.

  5. Nuclear Astrophysics and Neutron Cross Section Measurements Using the ORELA

    SciTech Connect

    Winters, R. R.

    2000-08-25

    This is the final report for a research program which has been continuously supported by the AEC, ERDA, or USDOE since 1973. The neutron total and capture cross sections for n + {sup 88}Sr have been measured over the neutron energy range 100 eV to 1 MeV. The report briefly summaries our results and the importance of this work for nucleosynthesis and the optical model.

  6. Analysis of charged-current neutrino-nucleus cross section

    SciTech Connect

    Megias, G.; Caballero, J. A.

    2013-06-10

    A study of the cross section for chaged-current quasielastic (CCQE) scattering on nuclei has been performed using a description of nuclear dynamics based on the Relativistic Fermi Gas model (RFG). The role played by different parametrizations for the weak nucleon form factors is analyzed taking into account the relevance of the axial mass value. The results obtained are compared with the recent data for neutrinos measured by the MiniBooNE Collaboration.

  7. Neutron-Induced Cross Sections Measurements of Calcium

    SciTech Connect

    Guber, Klaus H; Kopecky, S.; Schillebeeckx, P.; Kauwenberghs, K.; Siegler, P.

    2013-01-01

    To support the US Department of Energy Nuclear Criticality Safety Program neutron induced cross section experiments were performed at the Geel Electron Linear Accelerator of the Institute for Reference Material and Measurements of the Joint Research Centers, European Union. Neutron capture and transmission measurements were carried out using a metallic calcium sample. The obtained data will be used for a new calcium evaluation, which will be submitted with its covariances to the ENDBF/B nuclear data base.

  8. Overview of recent U235 neutron cross section evaluation work

    SciTech Connect

    Lubitz, C.

    1998-10-01

    This report is an overview (through 1997) of the U235 neutron cross section evaluation work at Oak Ridge National Laboratory (ORNL), AEA Technology (Harwell) and Lockheed Martin Corp.-Schenectady (LMS), which has influenced, or appeared in, ENDF/B-VI through Release 5. The discussion is restricted to the thermal and resolved resonance regions, apart from some questions about the unresolved region which still need investigation. The important role which benchmark testing has played will be touched on.

  9. Effect of core polarizability on photoionization cross-section calculations.

    NASA Technical Reports Server (NTRS)

    Kirkpatrick, R. C.

    1972-01-01

    Demonstration of the importance of core polarizability in a case where cancellation is only moderate, with suggestion of an improvement to the scaled Thomas-Fermi (STF) wave functions of Stewart and Rotenberg (1965). The inclusion of dipole polarizability of the core for argon is shown to substantially improve the agreement between the theoretical and experimental photoionization cross sections for the ground-state configuration.

  10. Cross-sectional transmission electron microscopy of semiconductors

    SciTech Connect

    Sadana, D.K.

    1982-10-01

    A method to prepare cross-sectional (X) semiconductor specimens for transmission electron microscopy (TEM) has been described. The power and utility of XTEM has been demonstrated. It has been shown that accuracy and interpretation of indirect structural-defects profiling techniques, namely, MeV He/sup +/ channeling and secondary ion mass spectrometry (SIMS) can be greatly enhanced by comparing their results with those obtained by XTEM from the same set of samples.

  11. Top quark pair production cross section at the Tevatron

    SciTech Connect

    Cortiana, Giorgio; /INFN, Padua /Padua U.

    2008-04-01

    Top quark pair production cross section has been measured at the Tevatron by CDF and D0 collaborations using different channels and methods, in order to test standard model predictions, and to search for new physics hints affecting the t{bar t} production mechanism or decay. Measurements are carried out with an integrated luminosity of 1.0 to 2.0 fb{sup -1}, and are found to be consistent with standard model expectations.

  12. Workshop on a Cross Section of Archean Crust

    NASA Technical Reports Server (NTRS)

    Ashwal, L. D. (Editor); Card, K. D. (Editor)

    1983-01-01

    Various topics relevant to crustal genesis, especially the relationship between Archean low - and high-grade terrains, were discussed. The central Superior Province of the Canadian Shield was studied. Here a 120 km-wide transition from subgreenschist facies rocks of the Michipicoten greenstone belt to granulite facies rocks of the Kapuskasing structural zone represents an oblique cross section through some 20 km of crust, uplifted along a northwest-dipping thrust fault.

  13. Radial Eigenmodes for a Toroidal Waveguide with Rectangular Cross Section

    SciTech Connect

    Rui Li

    2012-07-01

    In applying mode expansion to solve the CSR impedance for a section of toroidal vacuum chamber with rectangular cross section, we identify the eigenvalue problem for the radial eigenmodes which is different from that for cylindrical structures. In this paper, we present the general expressions of the radial eigenmodes, and discuss the properties of the eigenvalues on the basis of the Sturm-Liouville theory.

  14. Isotopic dependence of induced fission cross sections for heavy nuclei

    NASA Astrophysics Data System (ADS)

    Zubov, A. S.; Bolgova, O. N.; Adamian, G. G.; Antonenko, N. V.; Scheid, W.

    2009-10-01

    Using the statistical model, we calculate the induced fission cross sections for the nuclei 211-223Ra in their peripheral collisions with 208Pb. The role of closed shell N = 126 is studied. Level densities of the Fermi-gas model and of the model with collective enhancement are used. Taking into account the particle-hole excitation in addition to the collective Coulomb excitation, we obtain satisfactory agreement with the experimental data.

  15. Cross-sectional echocardiographic diagnosis of systemic venous return.

    PubMed Central

    Huhta, J C; Smallhorn, J F; Macartney, F J; Anderson, R H; de Leval, M

    1982-01-01

    To determine the sensitivity and specificity of cross-sectional echocardiography in diagnosing anomalous systemic venous return we used the technique in 800 consecutive children with congenital heart disease and whom the diagnosis was ultimately confirmed by angiography. Cross-sectional echocardiography was performed without prior knowledge of the diagnosis in all but 11 patients, who were recalled because of a known abnormality of atrial situs. The sensitivity of cross-sectional echocardiographic detection of various structures was as follows: right superior vena cava 792/792 (100%); left superior vena cava 46/48 (96%); bilateral superior vena cava 38/40 (95%); bridging innominate vein with bilateral superior vena cava 13/18 (72%); connection of superior caval segment to heart (coronary sinus or either atrium) (100%); absence of suprarenal inferior vena cava 23/23 (100%); azygos continuation of the inferior vena cava 31/33 (91%); downstream connection of azygos continuation, once seen, 21/21 (100%); partial anomalous hepatic venous connection (one hepatic vein not connected to the inferior vena cava) 1/1 (100%); total anomalous hepatic venous connection (invariably associated with left isomerism) 23/23 (100%). The specificity of each above diagnoses was 100% except in one infant with exomphalos in whom absence of the suprarenal inferior vena cava was incorrectly diagnosed. Thus cross-sectional echocardiography is an extremely specific and highly sensitive method of recognizing anomalous systemic venous return. It is therefore of great value of planning both cardiac catheterisation and cannulation for open heart surgery. Images PMID:6751361

  16. Top Quark Production Cross Section at the Tevatron

    SciTech Connect

    Shabalina, E.; /Chicago U.

    2006-05-01

    An overview of the preliminary results of the top quark pair production cross section measurements at a center-of-mass energy of 1.96 TeV carried out by the CDF and D0 collaborations is presented. The data samples used for the analyses are collected in the current Tevatron run and correspond to an integrated luminosity from 360 pb{sup -1} up to 760 pb{sup -1}.

  17. 13. Photocopy of drawing dated January 20, 1958, CROSS SECTION, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    13. Photocopy of drawing dated January 20, 1958, CROSS SECTION, REHABILITATION OF PIERSHED AT FOOT OF 29TH ST. city of New York Department of Marine and Aviation, Contract 3049, Drawing 3. (On file, City of New York Department of Ports and Trade). - South Brooklyn Freight Terminal, 29th Street Pier, Opposite end of Twenty-ninth Street on upper New York Bay, Brooklyn, Kings County, NY

  18. Neutrino and Antineutrino Cross sections at MiniBooNE

    SciTech Connect

    Dharmapalan, Ranjan; /Alabama U.

    2011-10-01

    The MiniBooNE experiment has reported a number of high statistics neutrino and anti-neutrino cross sections -among which are the charged current quasi-elastic (CCQE) and neutral current elastic (NCE) neutrino scattering on mineral oil (CH2). Recently a study of the neutrino contamination of the anti-neutrino beam has concluded and the analysis of the anti-neutrino CCQE and NCE scattering is ongoing.

  19. Inclusive jet cross-section measurement at CDF

    SciTech Connect

    Norniella, Olga; /Barcelona, IFAE

    2007-05-01

    The CDF Collaboration has measured the inclusive jet cross section using 1992-93 collider data at 1.8 TeV. The CDF measurement is in very good agreement with NLO QCD predictions for transverse energies (E{sub T}) below 200 GeV. However, it is systematically higher than NLO QCD predictions for E{sub T} above 200 GeV.

  20. Study of Exotic Nuclear Structures via Total Reaction Cross Sections

    NASA Astrophysics Data System (ADS)

    Takechi, Maya

    2009-10-01

    Nuclear radius is one of the most basic physical quantities to study unknown exotic nuclei. A number of radii for unstable nuclei were studied through measurements of interaction cross sections (σI) at high energies, using the Glauber-type calculation (Optical-Limit approximation (OLA) of Glauber theory) to investigate halo and skin structures of exotic nuclei. On the other hand, it was indicated that reaction cross sections (σR) at intermediate energies (from several tens to hundreds of MeV/nucleon) were more sensitive to dilute nucleon density distribution owing to large nucleon-nucleon total cross sections (σNN) compared to high-energy region. Recently, we developed a new method to deduce nucleon density distributions from the energy dependences of σ R, through the precise measurements of σ R for various nuclei and some modifications of Glauber-type calculation. Using this method, we studied nucleon density distributions of light nuclei by measuring σ R for those nuclei at HIMAC (Heavy ion Medical Accelerator in CHIBA), NIRS (National Institute of Radiological Sciences). And very recently, we deduced nuclear radii of neutron-rich Ne isotopes (^28-32Ne) which are in the island-of-inversion region by measuring σI using BigRIPS at RIBF (RI Beam Factory) to study nuclear structures of those isotopes using our method. In this workshop, results of nucleon density distributions obtained at HIMAC and results of the studies of Ne isotopes at RIBF will be introduced and discussed.

  1. Suppression of Wake Vortices Using Periodic Cross-Section Variations

    NASA Astrophysics Data System (ADS)

    Bouabdallah, A.; Oualli, H.; Benlahnache, A.; Menad, Y.; Gad-El-Hak, M.

    2013-11-01

    Vortices in the wake of blunt bodies are responsible for significant portion of the drag. An active flow control strategy is designed to inhibit the shedding of such vortex structures. A numerical study is conducted to investigate the effect of periodic cross-section variations on the shed vortices. We use an LES scheme with a Smagorinsky-Lilly subgrid model. The two-dimensional body sinusoidally changes its cross-section from circular to elliptic. The amplitude varies in the range of 5-100% of the nominal cylinder's diameter, and the oscillation frequency varies in the range of 0.2-10 times the cylinder's natural shedding frequency. The von Kármán vortex street is most sensitive to the cross-section variations at a Reynolds number of 3,740. At this Re, the boundary layer is subcritical, and the wake is predominately bidimensional. The flow exhibits a cascade of bifurcations identified by the shifting of the shedding mode. When the flow control strategy is optimized, as much as 65% drag reduction is achieved, which is a direct result of the shedding mechanism inhibition. An experimental validation of this result is forthcoming.

  2. Coherent set of electron cross sections for argon

    NASA Astrophysics Data System (ADS)

    Alves, L. L.; Ferreira, C. M.

    2011-10-01

    This paper presents a coherent set of electron impact cross sections for argon (elastic momentum-transfer, inelastic for the excitation of 37 levels Ar(4s,4p,3d,5p,4d,6s) and ionization), which was recently uploaded onto the LXcat IST-Lisbon database. The cross section set was validated by comparing calculated swarm parameters (electron mobility and characteristic energy) and rate coefficients (Townsend ionization coefficient and direct + cascade excitation coefficients to the 4s and 4p states) with available experimental data, for E / N = 10-4 - 100 Td and Tg = 300, 77 K. The validation procedure involves the solution to the homogeneous two-term electron Boltzmann equation, resorting to three different solvers: (i) IST-Lisbon's (ii) BOLSIG+ (v1.2) with LXcat; (iii) BOLSIG+ (v1.23). The results obtained with these solvers are compared to evidence the importance of certain numerical features related with both the energy-grid (number of points, grid-type and maximum energy value) and the interpolation scheme adopted for the cross sections. In particular, the latter can cause a 6% variation on the values of swarm parameters at intermediate E/Ns.

  3. Electron impact excitation cross sections in F-like selenium

    SciTech Connect

    Chen Guoxin |; Ong, P.P.

    1998-09-01

    Cross sections for excitation induced by electron collision between low-lying 1s{sup 2}2s{sup 2}2p{sup 5} and 1s{sup 2}2s2p{sup 6} states of f-like selenium and from these states to singly excited states with the excited electron occupying the M shell have been calculated by relativistic distorted-wave Born procedures. The GRASP{sup 2} code was used for the atomic structure calculations. The continuum orbitals for the construction of continuum states were computed in the distorted-wave approximation, in which the distorted-wave potential used was the spherically averaged potential of the nucleus plus the potential of the bound electrons of the bound state. The cross sections for excitations were computed first by a 233-level multiconfiguration Dirac-Fock (MCDF) configuration expansion and then by a 279-level MCDF configuration expansion. The latter procedure, which also took into account contributions from all the participating singly excited N-shell states, was found to be necessary for improved accuracy. The cross section data should be a useful reference in the development of x-ray lasers and other related fields involving highly stripped ions.

  4. A study of radar cross section measurement techniques

    NASA Technical Reports Server (NTRS)

    Mcdonald, Malcolm W.

    1986-01-01

    Past, present, and proposed future technologies for the measurement of radar cross section were studied. The purpose was to determine which method(s) could most advantageously be implemented in the large microwave anechoic chamber facility which is operated at the antenna test range site. The progression toward performing radar cross section measurements of space vehicles with which the Orbital Maneuvering Vehicle will be called upon to rendezvous and dock is a natural outgrowth of previous work conducted in recent years of developing a high accuracy range and velocity sensing radar system. The radar system was designed to support the rendezvous and docking of the Orbital Maneuvering Vehicle with various other space vehicles. The measurement of radar cross sections of space vehicles will be necessary in order to plan properly for Orbital Maneuvering Vehicle rendezvous and docking assignments. The methods which were studied include: standard far-field measurements; reflector-type compact range measurements; lens-type compact range measurement; near field/far field transformations; and computer predictive modeling. The feasibility of each approach is examined.

  5. Reconciling cross-sectional with longitudinal observations on annual decline.

    PubMed

    Vollmer, W M

    1993-01-01

    In summary, numerous factors may contribute to observed differences between longitudinally and cross-sectionally derived measures of annual decline in lung function. The direction and magnitude of these differences appear hard to predict. Furthermore, although these differences can be minimized by careful modeling of the data, they cannot, in general, be completely avoided. It seems plausible, however, that both types of studies should give similar qualitative comparisons of risk factor effects if appropriately modeled. Longitudinal studies are likely to provide the most accurate and reliable estimates of lung function decline for both individuals and populations. Such data may be especially useful in identifying individuals with accelerated declines in lung function but who still have "normal" lung function as measured cross-sectionally. However, such studies require careful attention to quality control and typically require at least 4 years of follow-up before the noise in the data settles down. Multiple measurements, preferably four or more, are also necessary to reliably detect and adjust for survey effects. Cross-sectional studies, on the other hand, are simpler, cheaper, and quicker to conduct than are longitudinal studies. They may be particularly useful as a screening tool for identifying potentially affected or high-risk subjects (e.g., those with low levels of lung function) who may require further medical follow-up and/or ongoing monitoring. Both types of studies have a role in population-based occupational health hazard assessments.

  6. Neutron Capture Cross Sections for the Re/Os Clock

    SciTech Connect

    Mosconi, M.; Heil, M.; Kaeppeler, F.; Plag, R.; Voss, F.; Wisshak, K.; Mengoni, A.; Cennini, P.; Chiaveri, E.; Ferrari, A.; Fitzpatrick, L.; Herrera-Martinez, A.; Kadi, Y.; Sarchiapone, L.; Vlachoudis, V.; Wendler, H.; Aerts, G.; Andriamonje, S.; Berthoumieux, E.; Dridi, W.

    2005-05-24

    The radioactive decay of 187Re {yields} 187Os (t1/2 = 43 Gyr) is suited for dating the onset of heavy-element nucleosynthesis. The radiogenic contribution to the 187Os abundance is the difference between the natural abundance and the corresponding s-process component. This component can be obtained via the well-established {sigma}N systematics using the neighboring s-only isotope 186Os, provided the neutron-capture cross sections of both isotopes are known with sufficient accuracy. We report on a new set of experiments performed with a C6D6 detector array at the n{sub T}OF neutron spallation facility of CERN. The capture cross sections of 186Os, 187Os, and 188Os have been measured in the neutron-energy range between 1 eV and 1 MeV, and Maxwellian-averaged cross sections were deduced for the relevant thermal energies from kT=5 keV to 100 keV.

  7. Fission cross section uncertainties with the NIFFTE TPC

    NASA Astrophysics Data System (ADS)

    Sangiorgio, Samuele; Niffte Collaboration

    2014-09-01

    Nuclear data such as neutron-induced fission cross sections play a fundamental role in nuclear energy and defense applications. In recent years, understanding of these systems has become increasingly dependent upon advanced simulation and modeling, where uncertainties in nuclear data propagate in the expected performances of existing and future systems. It is important therefore that uncertainties in nuclear data are minimized and fully understood. For this reason, the Neutron Induced Fission Fragment Tracking Experiment (NIFFTE) uses a Time Projection Chamber (TPC) to measure energy-differential (n,f) cross sections with unprecedented precision. The presentation will discuss how the capabilities of the NIFFTE TPC allow to directly measures systematic uncertainties in fission cross sections, in particular for what concerns fission-fragment identification, and target and beam uniformity. Preliminary results from recent analysis of 238U/235U and 239Pu/235U data collected with the TPC will be presented. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  8. Measurements of Fe and Ar fragmentation cross sections

    NASA Technical Reports Server (NTRS)

    Lau, K. H.; Mewaldt, R. A.; Stone, E. C.

    1985-01-01

    Measurements are reported of the yields of individual isotopes of Cr to Co(Z = 24 to 27) resulting from the fragmentation of Fe-56, and the isotopes of Mg to K(Z = 12 to 19) resulting from the fragmentation of Ar-40. Recent advances in the resolution and collecting power of cosmic ray instrumentation, have led to dramatic improvements in the precision of cosmic ray composition measurements, both elemental and isotopic. The interpretation of these measurements is presently limited by uncertainties in the fragmentation cross-sections needed to correct for nuclear interactions with the interstellar gas. Cosmic ray propagation codes now rely mainly on semi-empirical cross-section formulae developed by Silberberg and Tsao (S&T), which have a typical uncertainty of approximately 25%. Relative isotope yields from the fragmentation of approximately 380 MeV/nucleon Fe-56 e and approximately 210 MeV/nucleon Ar-40 r in CH2 targets, observed during the calibration of two cosmic ray spectrometers at the Lawrence Berkeley Laboratory Bevalac are reported. These are compared with calculated yeilds based on the S&T cross-section formulae.

  9. Extension of the Bgl Broad Group Cross Section Library

    NASA Astrophysics Data System (ADS)

    Kirilova, Desislava; Belousov, Sergey; Ilieva, Krassimira

    2009-08-01

    The broad group cross-section libraries BUGLE and BGL are applied for reactor shielding calculation using the DOORS package based on discrete ordinates method and multigroup approximation of the neutron cross-sections. BUGLE and BGL libraries are problem oriented for PWR or VVER type of reactors respectively. They had been generated by collapsing the problem independent fine group library VITAMIN-B6 applying PWR and VVER one-dimensional radial model of the reactor middle plane using the SCALE software package. The surveillance assemblies (SA) of VVER-1000/320 are located on the baffle above the reactor core upper edge in a region where geometry and materials differ from those of the middle plane and the neutron field gradient is very high which would result in a different neutron spectrum. That is why the application of the fore-mentioned libraries for the neutron fluence calculation in the region of SA could lead to an additional inaccuracy. This was the main reason to study the necessity for an extension of the BGL library with cross-sections appropriate for the SA region. Comparative analysis of the neutron spectra of the SA region calculated by the VITAMIN-B6 and BGL libraries using the two-dimensional code DORT have been done with purpose to evaluate the BGL applicability for SA calculation.

  10. Deuterium target data for precision neutrino-nucleus cross sections

    DOE PAGES

    Meyer, Aaron S.; Betancourt, Minerba; Gran, Richard; Hill, Richard J.

    2016-06-23

    Amplitudes derived from scattering data on elementary targets are basic inputs to neutrino-nucleus cross section predictions. A prominent example is the isovector axial nucleon form factor, FA(q2), which controls charged current signal processes at accelerator-based neutrino oscillation experiments. Previous extractions of FA from neutrino-deuteron scattering data rely on a dipole shape assumption that introduces an unquantified error. A new analysis of world data for neutrino-deuteron scattering is performed using a model-independent, and systematically improvable, representation of FA. A complete error budget for the nucleon isovector axial radius leads to rA2 = 0.46(22)fm2, with a much larger uncertainty than determined inmore » the original analyses. The quasielastic neutrino-neutron cross section is determined as σ(νμn → μ-p)|Ev=1GeV = 10.1(0.9)×10-39cm2. The propagation of nucleon-level constraints and uncertainties to nuclear cross sections is illustrated using MINERvA data and the GENIE event generator. Furthermore, these techniques can be readily extended to other amplitudes and processes.« less

  11. Cross-sectional TEM analysis of solvent-cast SBS thin films

    SciTech Connect

    Kim, G.; Libera, M.

    1996-12-31

    Block copolymers can assume a range of microphase-separated morphologies, and the dependence of morphology on temperature and composition is an area of active research. Our work has been studying the morphology of solvent-cast thin films of polystyrene-polybutadiene-polystyrene (SBS) as a function of solvent evaporation rate and post-specimen annealing. This paper describes the analysis of thin film cross-sections to distinguish between possible morphologies.

  12. Cross Section and Analyzing Power Measurements for Neutron Scattering from Aluminum and Cobalt and Spin - Cross Section Calculations

    NASA Astrophysics Data System (ADS)

    Nagadi, Mahmoud Mohamud

    Differential cross sections and analyzing power data have been measured for ^{27} Al and ^{59}Co at 15.5 MeV. Cross section data was also measured for ^{59}Co at 10, 12, 14, 17, and 19 MeV using standard time-of-flight techniques at the Triangle Universities Nuclear Laboratory (TUNL). Absolute normalization of the sigma(theta) data was performed using n-p scattering measurements. Both sigma(theta) and rm A_{y}(theta) were corrected for finite geometry, attenuation, relative efficiency, and multiple scattering effects using Monte Carlo techniques. A large data base was formed from our data and the existing data on ^{27}Al and ^{59}Co. This data base was used to develop a Dispersive Optical Model (DOM) and a Coupled Channels Model (CCM). The DOM model describes the data quite well above 8 MeV for ^{27 }Al and ^{59}Co. However, for data below 8 MeV the model is not as satisfactory, perhaps because of angular momentum l-dependencies in the absorptive potential. The CCM improved the description of the data over the DOM, but still does not describe the data well at low energies. The DOM and CCM for ^{27} Al and ^{59}Co were used to describe the spin-spin cross section data for ^{27}Al and ^{59}Co. We obtained a good fit for the spin-spin cross section with both the DOM and CCM with the spin-spin real surface parameters of V _{rm ss} = 0.80 MeV, r _{rm ss} = 1.00 fm and a _{rm ss} = 0.654 for both ^{27}Al and ^{59}Co. A surprising relation between the spin-spin cross section and the derivative of the total cross section with respect to energy, was discovered: sigma_{ss } = c {dsigma_{T} over dE} where c is a constant related to the slope of the real central potential and spin-spin potential strength. This observation is not yet understood.

  13. Electron impact ionisation cross sections of iron hydrogen clusters

    NASA Astrophysics Data System (ADS)

    Huber, Stefan E.; Sukuba, Ivan; Urban, Jan; Limtrakul, Jumras; Probst, Michael

    2016-09-01

    We computed electron impact ionisation cross sections (EICSs) of iron hydrogen clusters, FeHn with n = 1,2,...,10, from the ionisation threshold to 10 keV using the Deutsch-Märk (DM) and the binary-encounter-Bethe (BEB) formalisms. The maxima of the cross sections for the iron hydrogen clusters range from 6.13 × 10-16 cm2 at 60 eV to 8.76 × 10-16 cm2 at 76 eV for BEB-AE (BEB method based on quantum-chemical data from all-electron basis sets) calculations, from 4.15 × 10-16 cm2 at 77 eV to 7.61 × 10-16 cm2 at 80 eV for BEB-ECP (BEB method based on quantum-chemical data from effective-core potentials for inner-core electrons) calculations and from 2.49 × 10-16 cm2 at 43.5 eV to 7.04 × 10-16 cm2 at 51 eV for the DM method. Cross sections calculated via the BEB method are substantially higher than the ones obtained via the DM method, up to a factor of about two for FeH and FeH2. The formation of Fe-H bonds depopulates the iron 4s orbital, causing significantly lower cross sections for the small iron hydrides compared to atomic iron. Both the DM and BEB cross sections can be fitted perfectly against a simple expression used in modelling and simulation codes in the framework of nuclear fusion research. The energetics of the iron hydrogen clusters change substantially when exact exchange is present in the density functional, while the cluster geometries do not depend on this choice. Supplementary material in the form of one pdf file available from the Journal web page athttp://dx.doi.org/10.1140/epjd/e2016-70292-4

  14. From ZZ to ZH : How Low Can These Cross Sections Go or Everybody, Let's Cross Section Limbo!

    SciTech Connect

    Strauss, Emanuel Alexandre

    2009-08-01

    We report on two searches performed at the D0 detector at the Fermi National Laboratory. The first is a search for Z di-boson production with a theoretical cross section of 1.4 pb. The search was performed on 2.6 fb-1 of data and contributed to the first observation of ZZ production at a hadron collider. The second is a search for a low mass Standard Model Higgs in 4.2 fb-1 of data. The Higgs boson is produced in association with a Z boson where the Higgs decays hadronically and the Z decays to two leptons. The ZZ search was performed in both the di-electron and di-muon channels. For the ZH search, we will focus on the muonic decays where we expanded the traditional coverage by considering events in which one of the two muons fails the selection requirement, and is instead reconstructed as an isolated track. We consider Higgs masses between 100 and 150 GeV, with theoretical cross sections ranging from 0.17 to 0.042 pb, and set upper limits on the ZH production cross-section at 95% confidence level.

  15. Effect of transition in cross-sectional shape on the development of the velocity and pressure distribution of turbulent flow in pipes

    NASA Technical Reports Server (NTRS)

    Mayer, Edwin

    1939-01-01

    With regard to the change in shape of the cross section while the area remains constant, no investigation results are as yet available. Such an investigation will be the subject of the present paper. For this purpose it is necessary to consider the velocity and pressure relations over each entire cross section so that we are confronted with a three-dimensional problem.

  16. Photoionization cross-section of isotropic defects or impurity centers in isolators

    NASA Astrophysics Data System (ADS)

    Lima, H.; Batista, J. V.; Couto dos Santos, M. A.

    2016-08-01

    An analytical expression to calculate the photoionization cross-section of isotropic defects or impurity centers is being proposed by using the time-dependent perturbation theory. The ground-state wave function of the electron captured in the impurity state is described by a three-dimensional isotropic harmonic oscillator and the electron excited state in the continuum conduction band is described by a plane wave. The expression has been obtained considering all multipoles terms in the Hamiltonian, and that the radiation field which interacts with electrons is semi-classical and linearly polarized. This approximation is assumed because the effects of the linear contribution are dominant. The available data of the Al2O3:C and Lu2SiO5:Ce systems are in good agreement with our predictions. Such satisfactory comparison is a strong indication that the present model can be used to provide good predictions of the photoionization cross-section in several areas.

  17. Reduced backscattering cross section (Sigma degree) data from the Skylab S-193 radar altimeter

    NASA Technical Reports Server (NTRS)

    Brown, G. S.

    1975-01-01

    Backscattering cross section per unit scattering area data, reduced from measurements made by the Skylab S-193 radar altimeter over the ocean surface are presented. Descriptions of the altimeter are given where applicable to the measurement process. Analytical solutions are obtained for the flat surface impulse response for the case of a nonsymmetrical antenna pattern. Formulations are developed for converting altimeter AGC outputs into values for the backscattering cross section. Reduced data are presented for Missions SL-2, 3 and 4 for all modes of the altimeter where sufficient calibration existed. The problem of interpreting land scatter data is also discussed. Finally, a comprehensive error analysis of the measurement is presented and worst case random and bias errors are estimated.

  18. Contactless Visualization of Latent Fingerprints on Nonporous Curved Surfaces of Circular Cross Section.

    PubMed

    Low, Wei Zeng; Khoo, Bee Ee; Abdullah, Ahmad Fahmi Lim Bin

    2016-07-01

    Nondestructive techniques for gathering evidence are important in the field of forensics. Due to the geometry of the substrates, nondestructive visualization of fingermarks on curved surfaces remains challenging. A novel contactless technique was developed for visualizing and recording fingermark patterns on nonporous curved surfaces of circular cross section. The technique utilizes a plane mirror to transmit rays from a light source to illuminate the area of interest for fingermark visualization. The fingermark acquisition system consists of a digital single-lens reflex (SLR) camera, a plane mirror, and a white light source. Mathematical equations are used to calculate the mirror size. Experiments were performed on various curved surfaces to determine the feasibility and effectiveness of the technique. Spectral Image Validation and Verification (SIVV) was used to analyze the captured images. The results of this study indicate that the technique described here is able to reveal fingermark patterns on curved surfaces of circular cross section. PMID:27364293

  19. Upper Airway Changes after Orthodontic Extraction Treatment in Adults: A Preliminary Study using Cone Beam Computed Tomography

    PubMed Central

    Zhang, Jingjing; Chen, Gui; Li, Weiran; Xu, Tianmin; Gao, Xuemei

    2015-01-01

    Objective Whether the orthodontic treatment with premolar extraction and maximum anchorage in adults will lead to a narrowed upper airway remains under debated. The study aims to investigate the airway changes after orthodontic extraction treatment in adult patients with Class II and hyperdivergent skeletal malocclusion. Materials and Methods This retrospective study enrolled 18 adults with Class II and hyperdivergent skeletal malocclusion (5 males and 13 females, 24.1 ± 3.8 years of age, BMI 20.33 ± 1.77 kg/m2). And 18 untreated controls were matched 1:1 with the treated patients for age, sex, BMI, and skeletal pattern. CBCT images before and after treatment were obtained. DOLPHIN 11.7 software was used to reconstruct and measure the airway size, hyoid position, and craniofacial structures. Changes in the airway and craniofacial parameters from pre to post treatment were assessed by Wilcoxon signed rank test. Mann-Whitney U test was used in comparisons of the airway parameters between the treated patients and the untreated controls. Significant level was set at 0.05. Results The upper and lower incisors retracted 7.87 mm and 6.10 mm based on the measurement of U1-VRL and L1-VRL (P < 0.01), while the positions of the upper and lower molars (U6-VRL, and L6-VRL) remained stable. Volume, height, and cross-sectional area of the airway were not significantly changed after treatment, while the sagittal dimensions of SPP-SPPW, U-MPW, PAS, and V-LPW were significantly decreased (P < 0.05), and the morphology of the cross sections passing through SPP-SPPW, U-MPW, PAS, and V-LPW became anteroposteriorly compressed (P <0.001). No significant differences in the airway volume, height, and cross-sectional area were found between the treated patients and untreated controls. Conclusions The airway changes after orthodontic treatment with premolar extraction and maximum anchorage in adults are mainly morphological changes with anteroposterior dimension compressed in airway cross

  20. Morphometric changes during the early airway response to allergen challenge in the rat.

    PubMed

    Du, T; Xu, L J; Lei, M; Wang, N S; Eidelman, D H; Ghezzo, H; Martin, J G

    1992-10-01

    The purpose of this study was to determine the relative contributions of airway wall edema and smooth muscle contraction to the early response (ER) of allergic bronchoconstriction. Brown Norway rats, 6 to 7 wk old, were sensitized with ovalbumin (OA). Anesthetized rats were challenged with either OA or saline 2 wk later. Pulmonary resistance (RL) was measured every minute until either it increased to 150% of the baseline, defined as a significant ER, or until 15 min elapsed. Eight OA-challenged test rats with a significant ER and eight saline-challenged control rats were used for morphometric studies. The lungs were quick-frozen with liquid nitrogen, processed with freeze substitution, and sagittal sections (5 microns) were stained with hematoxylin and eosin. The airway lumen subtended by the epithelial basement membrane (LuB) and cross sectional airway wall area (AW) of all airways were measured by camera lucida and digitization. The LuB and AW of each airway was standardized for size by dividing by the ideal airway lumen (LuBideal), which was calculated from the length of basement membrane, assuming a perfect circle in the unconstricted state. The cumulative frequency distribution of the LuB/LuBideal for the airways from test rats was shifted to the left compared with the control rats (p less than 0.01), indicating airway narrowing after challenge. Airway narrowing increased as a function of airway size. Cumulative frequency distributions of AW/LuBideal showed that there was a significant increase in the wall thickness of only the small airways of test animals.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1416393